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3058 lines
114 KiB
C
3058 lines
114 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#ifndef __LINUX_BPF_H__
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#define __LINUX_BPF_H__
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#include <linux/types.h>
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#include <linux/bpf_common.h>
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/* Extended instruction set based on top of classic BPF */
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/* instruction classes */
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#define BPF_ALU64 0x07 /* alu mode in double word width */
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/* ld/ldx fields */
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#define BPF_DW 0x18 /* double word (64-bit) */
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#define BPF_XADD 0xc0 /* exclusive add */
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/* alu/jmp fields */
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#define BPF_MOV 0xb0 /* mov reg to reg */
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#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
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/* change endianness of a register */
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#define BPF_END 0xd0 /* flags for endianness conversion: */
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#define BPF_TO_LE 0x00 /* convert to little-endian */
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#define BPF_TO_BE 0x08 /* convert to big-endian */
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#define BPF_FROM_LE BPF_TO_LE
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#define BPF_FROM_BE BPF_TO_BE
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/* jmp encodings */
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#define BPF_JNE 0x50 /* jump != */
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#define BPF_JLT 0xa0 /* LT is unsigned, '<' */
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#define BPF_JLE 0xb0 /* LE is unsigned, '<=' */
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#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
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#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
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#define BPF_JSLT 0xc0 /* SLT is signed, '<' */
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#define BPF_JSLE 0xd0 /* SLE is signed, '<=' */
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#define BPF_CALL 0x80 /* function call */
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#define BPF_EXIT 0x90 /* function return */
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/* Register numbers */
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enum {
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BPF_REG_0 = 0,
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BPF_REG_1,
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BPF_REG_2,
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BPF_REG_3,
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BPF_REG_4,
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BPF_REG_5,
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BPF_REG_6,
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BPF_REG_7,
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BPF_REG_8,
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BPF_REG_9,
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BPF_REG_10,
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__MAX_BPF_REG,
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};
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/* BPF has 10 general purpose 64-bit registers and stack frame. */
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#define MAX_BPF_REG __MAX_BPF_REG
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struct bpf_insn {
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__u8 code; /* opcode */
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__u8 dst_reg:4; /* dest register */
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__u8 src_reg:4; /* source register */
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__s16 off; /* signed offset */
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__s32 imm; /* signed immediate constant */
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};
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/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
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struct bpf_lpm_trie_key {
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__u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
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__u8 data[0]; /* Arbitrary size */
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};
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struct bpf_cgroup_storage_key {
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__u64 cgroup_inode_id; /* cgroup inode id */
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__u32 attach_type; /* program attach type */
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};
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/* BPF syscall commands, see bpf(2) man-page for details. */
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enum bpf_cmd {
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BPF_MAP_CREATE,
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BPF_MAP_LOOKUP_ELEM,
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BPF_MAP_UPDATE_ELEM,
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BPF_MAP_DELETE_ELEM,
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BPF_MAP_GET_NEXT_KEY,
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BPF_PROG_LOAD,
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BPF_OBJ_PIN,
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BPF_OBJ_GET,
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BPF_PROG_ATTACH,
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BPF_PROG_DETACH,
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BPF_PROG_TEST_RUN,
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BPF_PROG_GET_NEXT_ID,
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BPF_MAP_GET_NEXT_ID,
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BPF_PROG_GET_FD_BY_ID,
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BPF_MAP_GET_FD_BY_ID,
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BPF_OBJ_GET_INFO_BY_FD,
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BPF_PROG_QUERY,
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BPF_RAW_TRACEPOINT_OPEN,
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BPF_BTF_LOAD,
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BPF_BTF_GET_FD_BY_ID,
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BPF_TASK_FD_QUERY,
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BPF_MAP_LOOKUP_AND_DELETE_ELEM,
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};
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enum bpf_map_type {
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BPF_MAP_TYPE_UNSPEC,
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BPF_MAP_TYPE_HASH,
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BPF_MAP_TYPE_ARRAY,
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BPF_MAP_TYPE_PROG_ARRAY,
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BPF_MAP_TYPE_PERF_EVENT_ARRAY,
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BPF_MAP_TYPE_PERCPU_HASH,
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BPF_MAP_TYPE_PERCPU_ARRAY,
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BPF_MAP_TYPE_STACK_TRACE,
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BPF_MAP_TYPE_CGROUP_ARRAY,
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BPF_MAP_TYPE_LRU_HASH,
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BPF_MAP_TYPE_LRU_PERCPU_HASH,
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BPF_MAP_TYPE_LPM_TRIE,
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BPF_MAP_TYPE_ARRAY_OF_MAPS,
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BPF_MAP_TYPE_HASH_OF_MAPS,
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BPF_MAP_TYPE_DEVMAP,
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BPF_MAP_TYPE_SOCKMAP,
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BPF_MAP_TYPE_CPUMAP,
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BPF_MAP_TYPE_XSKMAP,
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BPF_MAP_TYPE_SOCKHASH,
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BPF_MAP_TYPE_CGROUP_STORAGE,
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BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
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BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
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BPF_MAP_TYPE_QUEUE,
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BPF_MAP_TYPE_STACK,
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};
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/* Note that tracing related programs such as
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* BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
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* are not subject to a stable API since kernel internal data
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* structures can change from release to release and may
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* therefore break existing tracing BPF programs. Tracing BPF
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* programs correspond to /a/ specific kernel which is to be
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* analyzed, and not /a/ specific kernel /and/ all future ones.
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*/
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enum bpf_prog_type {
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BPF_PROG_TYPE_UNSPEC,
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BPF_PROG_TYPE_SOCKET_FILTER,
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BPF_PROG_TYPE_KPROBE,
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BPF_PROG_TYPE_SCHED_CLS,
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BPF_PROG_TYPE_SCHED_ACT,
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BPF_PROG_TYPE_TRACEPOINT,
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BPF_PROG_TYPE_XDP,
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BPF_PROG_TYPE_PERF_EVENT,
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BPF_PROG_TYPE_CGROUP_SKB,
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BPF_PROG_TYPE_CGROUP_SOCK,
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BPF_PROG_TYPE_LWT_IN,
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BPF_PROG_TYPE_LWT_OUT,
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BPF_PROG_TYPE_LWT_XMIT,
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BPF_PROG_TYPE_SOCK_OPS,
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BPF_PROG_TYPE_SK_SKB,
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BPF_PROG_TYPE_CGROUP_DEVICE,
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BPF_PROG_TYPE_SK_MSG,
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BPF_PROG_TYPE_RAW_TRACEPOINT,
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BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
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BPF_PROG_TYPE_LWT_SEG6LOCAL,
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BPF_PROG_TYPE_LIRC_MODE2,
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BPF_PROG_TYPE_SK_REUSEPORT,
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BPF_PROG_TYPE_FLOW_DISSECTOR,
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};
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enum bpf_attach_type {
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BPF_CGROUP_INET_INGRESS,
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BPF_CGROUP_INET_EGRESS,
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BPF_CGROUP_INET_SOCK_CREATE,
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BPF_CGROUP_SOCK_OPS,
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BPF_SK_SKB_STREAM_PARSER,
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BPF_SK_SKB_STREAM_VERDICT,
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BPF_CGROUP_DEVICE,
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BPF_SK_MSG_VERDICT,
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BPF_CGROUP_INET4_BIND,
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BPF_CGROUP_INET6_BIND,
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BPF_CGROUP_INET4_CONNECT,
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BPF_CGROUP_INET6_CONNECT,
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BPF_CGROUP_INET4_POST_BIND,
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BPF_CGROUP_INET6_POST_BIND,
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BPF_CGROUP_UDP4_SENDMSG,
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BPF_CGROUP_UDP6_SENDMSG,
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BPF_LIRC_MODE2,
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BPF_FLOW_DISSECTOR,
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__MAX_BPF_ATTACH_TYPE
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};
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#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
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/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
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*
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* NONE(default): No further bpf programs allowed in the subtree.
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*
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* BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
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* the program in this cgroup yields to sub-cgroup program.
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*
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* BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
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* that cgroup program gets run in addition to the program in this cgroup.
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*
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* Only one program is allowed to be attached to a cgroup with
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* NONE or BPF_F_ALLOW_OVERRIDE flag.
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* Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
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* release old program and attach the new one. Attach flags has to match.
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*
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* Multiple programs are allowed to be attached to a cgroup with
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* BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
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* (those that were attached first, run first)
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* The programs of sub-cgroup are executed first, then programs of
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* this cgroup and then programs of parent cgroup.
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* When children program makes decision (like picking TCP CA or sock bind)
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* parent program has a chance to override it.
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*
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* A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
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* A cgroup with NONE doesn't allow any programs in sub-cgroups.
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* Ex1:
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* cgrp1 (MULTI progs A, B) ->
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* cgrp2 (OVERRIDE prog C) ->
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* cgrp3 (MULTI prog D) ->
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* cgrp4 (OVERRIDE prog E) ->
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* cgrp5 (NONE prog F)
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* the event in cgrp5 triggers execution of F,D,A,B in that order.
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* if prog F is detached, the execution is E,D,A,B
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* if prog F and D are detached, the execution is E,A,B
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* if prog F, E and D are detached, the execution is C,A,B
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*
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* All eligible programs are executed regardless of return code from
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* earlier programs.
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*/
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#define BPF_F_ALLOW_OVERRIDE (1U << 0)
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#define BPF_F_ALLOW_MULTI (1U << 1)
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/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
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* verifier will perform strict alignment checking as if the kernel
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* has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
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* and NET_IP_ALIGN defined to 2.
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*/
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#define BPF_F_STRICT_ALIGNMENT (1U << 0)
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/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the
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* verifier will allow any alignment whatsoever. On platforms
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* with strict alignment requirements for loads ands stores (such
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* as sparc and mips) the verifier validates that all loads and
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* stores provably follow this requirement. This flag turns that
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* checking and enforcement off.
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*
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* It is mostly used for testing when we want to validate the
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* context and memory access aspects of the verifier, but because
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* of an unaligned access the alignment check would trigger before
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* the one we are interested in.
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*/
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#define BPF_F_ANY_ALIGNMENT (1U << 1)
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/* when bpf_ldimm64->src_reg == BPF_PSEUDO_MAP_FD, bpf_ldimm64->imm == fd */
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#define BPF_PSEUDO_MAP_FD 1
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/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
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* offset to another bpf function
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*/
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#define BPF_PSEUDO_CALL 1
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/* flags for BPF_MAP_UPDATE_ELEM command */
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#define BPF_ANY 0 /* create new element or update existing */
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#define BPF_NOEXIST 1 /* create new element if it didn't exist */
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#define BPF_EXIST 2 /* update existing element */
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/* flags for BPF_MAP_CREATE command */
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#define BPF_F_NO_PREALLOC (1U << 0)
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/* Instead of having one common LRU list in the
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* BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
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* which can scale and perform better.
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* Note, the LRU nodes (including free nodes) cannot be moved
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* across different LRU lists.
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*/
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#define BPF_F_NO_COMMON_LRU (1U << 1)
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/* Specify numa node during map creation */
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#define BPF_F_NUMA_NODE (1U << 2)
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#define BPF_OBJ_NAME_LEN 16U
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/* Flags for accessing BPF object */
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#define BPF_F_RDONLY (1U << 3)
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#define BPF_F_WRONLY (1U << 4)
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/* Flag for stack_map, store build_id+offset instead of pointer */
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#define BPF_F_STACK_BUILD_ID (1U << 5)
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/* Zero-initialize hash function seed. This should only be used for testing. */
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#define BPF_F_ZERO_SEED (1U << 6)
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/* flags for BPF_PROG_QUERY */
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#define BPF_F_QUERY_EFFECTIVE (1U << 0)
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enum bpf_stack_build_id_status {
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/* user space need an empty entry to identify end of a trace */
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BPF_STACK_BUILD_ID_EMPTY = 0,
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/* with valid build_id and offset */
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BPF_STACK_BUILD_ID_VALID = 1,
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/* couldn't get build_id, fallback to ip */
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BPF_STACK_BUILD_ID_IP = 2,
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};
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#define BPF_BUILD_ID_SIZE 20
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struct bpf_stack_build_id {
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__s32 status;
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unsigned char build_id[BPF_BUILD_ID_SIZE];
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union {
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__u64 offset;
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__u64 ip;
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};
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};
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union bpf_attr {
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struct { /* anonymous struct used by BPF_MAP_CREATE command */
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__u32 map_type; /* one of enum bpf_map_type */
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__u32 key_size; /* size of key in bytes */
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__u32 value_size; /* size of value in bytes */
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__u32 max_entries; /* max number of entries in a map */
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__u32 map_flags; /* BPF_MAP_CREATE related
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* flags defined above.
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*/
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__u32 inner_map_fd; /* fd pointing to the inner map */
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__u32 numa_node; /* numa node (effective only if
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* BPF_F_NUMA_NODE is set).
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*/
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char map_name[BPF_OBJ_NAME_LEN];
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__u32 map_ifindex; /* ifindex of netdev to create on */
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__u32 btf_fd; /* fd pointing to a BTF type data */
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__u32 btf_key_type_id; /* BTF type_id of the key */
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__u32 btf_value_type_id; /* BTF type_id of the value */
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};
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struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
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__u32 map_fd;
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__aligned_u64 key;
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union {
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__aligned_u64 value;
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__aligned_u64 next_key;
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};
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__u64 flags;
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};
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struct { /* anonymous struct used by BPF_PROG_LOAD command */
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__u32 prog_type; /* one of enum bpf_prog_type */
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__u32 insn_cnt;
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__aligned_u64 insns;
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__aligned_u64 license;
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__u32 log_level; /* verbosity level of verifier */
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__u32 log_size; /* size of user buffer */
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__aligned_u64 log_buf; /* user supplied buffer */
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__u32 kern_version; /* not used */
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__u32 prog_flags;
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char prog_name[BPF_OBJ_NAME_LEN];
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__u32 prog_ifindex; /* ifindex of netdev to prep for */
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/* For some prog types expected attach type must be known at
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* load time to verify attach type specific parts of prog
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* (context accesses, allowed helpers, etc).
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*/
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__u32 expected_attach_type;
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__u32 prog_btf_fd; /* fd pointing to BTF type data */
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__u32 func_info_rec_size; /* userspace bpf_func_info size */
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__aligned_u64 func_info; /* func info */
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__u32 func_info_cnt; /* number of bpf_func_info records */
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__u32 line_info_rec_size; /* userspace bpf_line_info size */
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__aligned_u64 line_info; /* line info */
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__u32 line_info_cnt; /* number of bpf_line_info records */
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};
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struct { /* anonymous struct used by BPF_OBJ_* commands */
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__aligned_u64 pathname;
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__u32 bpf_fd;
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__u32 file_flags;
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};
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struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
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__u32 target_fd; /* container object to attach to */
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__u32 attach_bpf_fd; /* eBPF program to attach */
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__u32 attach_type;
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__u32 attach_flags;
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};
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struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
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__u32 prog_fd;
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__u32 retval;
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__u32 data_size_in; /* input: len of data_in */
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__u32 data_size_out; /* input/output: len of data_out
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* returns ENOSPC if data_out
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* is too small.
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*/
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__aligned_u64 data_in;
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__aligned_u64 data_out;
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__u32 repeat;
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__u32 duration;
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} test;
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struct { /* anonymous struct used by BPF_*_GET_*_ID */
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union {
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__u32 start_id;
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__u32 prog_id;
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__u32 map_id;
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__u32 btf_id;
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};
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__u32 next_id;
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__u32 open_flags;
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};
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struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
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__u32 bpf_fd;
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__u32 info_len;
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__aligned_u64 info;
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} info;
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struct { /* anonymous struct used by BPF_PROG_QUERY command */
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__u32 target_fd; /* container object to query */
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__u32 attach_type;
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__u32 query_flags;
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__u32 attach_flags;
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__aligned_u64 prog_ids;
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__u32 prog_cnt;
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} query;
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struct {
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__u64 name;
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__u32 prog_fd;
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} raw_tracepoint;
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struct { /* anonymous struct for BPF_BTF_LOAD */
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__aligned_u64 btf;
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__aligned_u64 btf_log_buf;
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__u32 btf_size;
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__u32 btf_log_size;
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__u32 btf_log_level;
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};
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struct {
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__u32 pid; /* input: pid */
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__u32 fd; /* input: fd */
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__u32 flags; /* input: flags */
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__u32 buf_len; /* input/output: buf len */
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__aligned_u64 buf; /* input/output:
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* tp_name for tracepoint
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* symbol for kprobe
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* filename for uprobe
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*/
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__u32 prog_id; /* output: prod_id */
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__u32 fd_type; /* output: BPF_FD_TYPE_* */
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__u64 probe_offset; /* output: probe_offset */
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__u64 probe_addr; /* output: probe_addr */
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} task_fd_query;
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} __attribute__((aligned(8)));
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/* The description below is an attempt at providing documentation to eBPF
|
|
* developers about the multiple available eBPF helper functions. It can be
|
|
* parsed and used to produce a manual page. The workflow is the following,
|
|
* and requires the rst2man utility:
|
|
*
|
|
* $ ./scripts/bpf_helpers_doc.py \
|
|
* --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
|
|
* $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
|
|
* $ man /tmp/bpf-helpers.7
|
|
*
|
|
* Note that in order to produce this external documentation, some RST
|
|
* formatting is used in the descriptions to get "bold" and "italics" in
|
|
* manual pages. Also note that the few trailing white spaces are
|
|
* intentional, removing them would break paragraphs for rst2man.
|
|
*
|
|
* Start of BPF helper function descriptions:
|
|
*
|
|
* void *bpf_map_lookup_elem(struct bpf_map *map, const void *key)
|
|
* Description
|
|
* Perform a lookup in *map* for an entry associated to *key*.
|
|
* Return
|
|
* Map value associated to *key*, or **NULL** if no entry was
|
|
* found.
|
|
*
|
|
* int bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags)
|
|
* Description
|
|
* Add or update the value of the entry associated to *key* in
|
|
* *map* with *value*. *flags* is one of:
|
|
*
|
|
* **BPF_NOEXIST**
|
|
* The entry for *key* must not exist in the map.
|
|
* **BPF_EXIST**
|
|
* The entry for *key* must already exist in the map.
|
|
* **BPF_ANY**
|
|
* No condition on the existence of the entry for *key*.
|
|
*
|
|
* Flag value **BPF_NOEXIST** cannot be used for maps of types
|
|
* **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all
|
|
* elements always exist), the helper would return an error.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_map_delete_elem(struct bpf_map *map, const void *key)
|
|
* Description
|
|
* Delete entry with *key* from *map*.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
|
|
* Description
|
|
* Push an element *value* in *map*. *flags* is one of:
|
|
*
|
|
* **BPF_EXIST**
|
|
* If the queue/stack is full, the oldest element is removed to
|
|
* make room for this.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_probe_read(void *dst, u32 size, const void *src)
|
|
* Description
|
|
* For tracing programs, safely attempt to read *size* bytes from
|
|
* address *src* and store the data in *dst*.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* u64 bpf_ktime_get_ns(void)
|
|
* Description
|
|
* Return the time elapsed since system boot, in nanoseconds.
|
|
* Return
|
|
* Current *ktime*.
|
|
*
|
|
* int bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
|
|
* Description
|
|
* This helper is a "printk()-like" facility for debugging. It
|
|
* prints a message defined by format *fmt* (of size *fmt_size*)
|
|
* to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if
|
|
* available. It can take up to three additional **u64**
|
|
* arguments (as an eBPF helpers, the total number of arguments is
|
|
* limited to five).
|
|
*
|
|
* Each time the helper is called, it appends a line to the trace.
|
|
* The format of the trace is customizable, and the exact output
|
|
* one will get depends on the options set in
|
|
* *\/sys/kernel/debug/tracing/trace_options* (see also the
|
|
* *README* file under the same directory). However, it usually
|
|
* defaults to something like:
|
|
*
|
|
* ::
|
|
*
|
|
* telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg>
|
|
*
|
|
* In the above:
|
|
*
|
|
* * ``telnet`` is the name of the current task.
|
|
* * ``470`` is the PID of the current task.
|
|
* * ``001`` is the CPU number on which the task is
|
|
* running.
|
|
* * In ``.N..``, each character refers to a set of
|
|
* options (whether irqs are enabled, scheduling
|
|
* options, whether hard/softirqs are running, level of
|
|
* preempt_disabled respectively). **N** means that
|
|
* **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
|
|
* are set.
|
|
* * ``419421.045894`` is a timestamp.
|
|
* * ``0x00000001`` is a fake value used by BPF for the
|
|
* instruction pointer register.
|
|
* * ``<formatted msg>`` is the message formatted with
|
|
* *fmt*.
|
|
*
|
|
* The conversion specifiers supported by *fmt* are similar, but
|
|
* more limited than for printk(). They are **%d**, **%i**,
|
|
* **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
|
|
* **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
|
|
* of field, padding with zeroes, etc.) is available, and the
|
|
* helper will return **-EINVAL** (but print nothing) if it
|
|
* encounters an unknown specifier.
|
|
*
|
|
* Also, note that **bpf_trace_printk**\ () is slow, and should
|
|
* only be used for debugging purposes. For this reason, a notice
|
|
* bloc (spanning several lines) is printed to kernel logs and
|
|
* states that the helper should not be used "for production use"
|
|
* the first time this helper is used (or more precisely, when
|
|
* **trace_printk**\ () buffers are allocated). For passing values
|
|
* to user space, perf events should be preferred.
|
|
* Return
|
|
* The number of bytes written to the buffer, or a negative error
|
|
* in case of failure.
|
|
*
|
|
* u32 bpf_get_prandom_u32(void)
|
|
* Description
|
|
* Get a pseudo-random number.
|
|
*
|
|
* From a security point of view, this helper uses its own
|
|
* pseudo-random internal state, and cannot be used to infer the
|
|
* seed of other random functions in the kernel. However, it is
|
|
* essential to note that the generator used by the helper is not
|
|
* cryptographically secure.
|
|
* Return
|
|
* A random 32-bit unsigned value.
|
|
*
|
|
* u32 bpf_get_smp_processor_id(void)
|
|
* Description
|
|
* Get the SMP (symmetric multiprocessing) processor id. Note that
|
|
* all programs run with preemption disabled, which means that the
|
|
* SMP processor id is stable during all the execution of the
|
|
* program.
|
|
* Return
|
|
* The SMP id of the processor running the program.
|
|
*
|
|
* int bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
|
|
* Description
|
|
* Store *len* bytes from address *from* into the packet
|
|
* associated to *skb*, at *offset*. *flags* are a combination of
|
|
* **BPF_F_RECOMPUTE_CSUM** (automatically recompute the
|
|
* checksum for the packet after storing the bytes) and
|
|
* **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
|
|
* **->swhash** and *skb*\ **->l4hash** to 0).
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
|
|
* Description
|
|
* Recompute the layer 3 (e.g. IP) checksum for the packet
|
|
* associated to *skb*. Computation is incremental, so the helper
|
|
* must know the former value of the header field that was
|
|
* modified (*from*), the new value of this field (*to*), and the
|
|
* number of bytes (2 or 4) for this field, stored in *size*.
|
|
* Alternatively, it is possible to store the difference between
|
|
* the previous and the new values of the header field in *to*, by
|
|
* setting *from* and *size* to 0. For both methods, *offset*
|
|
* indicates the location of the IP checksum within the packet.
|
|
*
|
|
* This helper works in combination with **bpf_csum_diff**\ (),
|
|
* which does not update the checksum in-place, but offers more
|
|
* flexibility and can handle sizes larger than 2 or 4 for the
|
|
* checksum to update.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
|
|
* Description
|
|
* Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
|
|
* packet associated to *skb*. Computation is incremental, so the
|
|
* helper must know the former value of the header field that was
|
|
* modified (*from*), the new value of this field (*to*), and the
|
|
* number of bytes (2 or 4) for this field, stored on the lowest
|
|
* four bits of *flags*. Alternatively, it is possible to store
|
|
* the difference between the previous and the new values of the
|
|
* header field in *to*, by setting *from* and the four lowest
|
|
* bits of *flags* to 0. For both methods, *offset* indicates the
|
|
* location of the IP checksum within the packet. In addition to
|
|
* the size of the field, *flags* can be added (bitwise OR) actual
|
|
* flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
|
|
* untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
|
|
* for updates resulting in a null checksum the value is set to
|
|
* **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
|
|
* the checksum is to be computed against a pseudo-header.
|
|
*
|
|
* This helper works in combination with **bpf_csum_diff**\ (),
|
|
* which does not update the checksum in-place, but offers more
|
|
* flexibility and can handle sizes larger than 2 or 4 for the
|
|
* checksum to update.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index)
|
|
* Description
|
|
* This special helper is used to trigger a "tail call", or in
|
|
* other words, to jump into another eBPF program. The same stack
|
|
* frame is used (but values on stack and in registers for the
|
|
* caller are not accessible to the callee). This mechanism allows
|
|
* for program chaining, either for raising the maximum number of
|
|
* available eBPF instructions, or to execute given programs in
|
|
* conditional blocks. For security reasons, there is an upper
|
|
* limit to the number of successive tail calls that can be
|
|
* performed.
|
|
*
|
|
* Upon call of this helper, the program attempts to jump into a
|
|
* program referenced at index *index* in *prog_array_map*, a
|
|
* special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
|
|
* *ctx*, a pointer to the context.
|
|
*
|
|
* If the call succeeds, the kernel immediately runs the first
|
|
* instruction of the new program. This is not a function call,
|
|
* and it never returns to the previous program. If the call
|
|
* fails, then the helper has no effect, and the caller continues
|
|
* to run its subsequent instructions. A call can fail if the
|
|
* destination program for the jump does not exist (i.e. *index*
|
|
* is superior to the number of entries in *prog_array_map*), or
|
|
* if the maximum number of tail calls has been reached for this
|
|
* chain of programs. This limit is defined in the kernel by the
|
|
* macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
|
|
* which is currently set to 32.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
|
|
* Description
|
|
* Clone and redirect the packet associated to *skb* to another
|
|
* net device of index *ifindex*. Both ingress and egress
|
|
* interfaces can be used for redirection. The **BPF_F_INGRESS**
|
|
* value in *flags* is used to make the distinction (ingress path
|
|
* is selected if the flag is present, egress path otherwise).
|
|
* This is the only flag supported for now.
|
|
*
|
|
* In comparison with **bpf_redirect**\ () helper,
|
|
* **bpf_clone_redirect**\ () has the associated cost of
|
|
* duplicating the packet buffer, but this can be executed out of
|
|
* the eBPF program. Conversely, **bpf_redirect**\ () is more
|
|
* efficient, but it is handled through an action code where the
|
|
* redirection happens only after the eBPF program has returned.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* u64 bpf_get_current_pid_tgid(void)
|
|
* Return
|
|
* A 64-bit integer containing the current tgid and pid, and
|
|
* created as such:
|
|
* *current_task*\ **->tgid << 32 \|**
|
|
* *current_task*\ **->pid**.
|
|
*
|
|
* u64 bpf_get_current_uid_gid(void)
|
|
* Return
|
|
* A 64-bit integer containing the current GID and UID, and
|
|
* created as such: *current_gid* **<< 32 \|** *current_uid*.
|
|
*
|
|
* int bpf_get_current_comm(char *buf, u32 size_of_buf)
|
|
* Description
|
|
* Copy the **comm** attribute of the current task into *buf* of
|
|
* *size_of_buf*. The **comm** attribute contains the name of
|
|
* the executable (excluding the path) for the current task. The
|
|
* *size_of_buf* must be strictly positive. On success, the
|
|
* helper makes sure that the *buf* is NUL-terminated. On failure,
|
|
* it is filled with zeroes.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* u32 bpf_get_cgroup_classid(struct sk_buff *skb)
|
|
* Description
|
|
* Retrieve the classid for the current task, i.e. for the net_cls
|
|
* cgroup to which *skb* belongs.
|
|
*
|
|
* This helper can be used on TC egress path, but not on ingress.
|
|
*
|
|
* The net_cls cgroup provides an interface to tag network packets
|
|
* based on a user-provided identifier for all traffic coming from
|
|
* the tasks belonging to the related cgroup. See also the related
|
|
* kernel documentation, available from the Linux sources in file
|
|
* *Documentation/cgroup-v1/net_cls.txt*.
|
|
*
|
|
* The Linux kernel has two versions for cgroups: there are
|
|
* cgroups v1 and cgroups v2. Both are available to users, who can
|
|
* use a mixture of them, but note that the net_cls cgroup is for
|
|
* cgroup v1 only. This makes it incompatible with BPF programs
|
|
* run on cgroups, which is a cgroup-v2-only feature (a socket can
|
|
* only hold data for one version of cgroups at a time).
|
|
*
|
|
* This helper is only available is the kernel was compiled with
|
|
* the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
|
|
* "**y**" or to "**m**".
|
|
* Return
|
|
* The classid, or 0 for the default unconfigured classid.
|
|
*
|
|
* int bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
|
|
* Description
|
|
* Push a *vlan_tci* (VLAN tag control information) of protocol
|
|
* *vlan_proto* to the packet associated to *skb*, then update
|
|
* the checksum. Note that if *vlan_proto* is different from
|
|
* **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
|
|
* be **ETH_P_8021Q**.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_vlan_pop(struct sk_buff *skb)
|
|
* Description
|
|
* Pop a VLAN header from the packet associated to *skb*.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
|
|
* Description
|
|
* Get tunnel metadata. This helper takes a pointer *key* to an
|
|
* empty **struct bpf_tunnel_key** of **size**, that will be
|
|
* filled with tunnel metadata for the packet associated to *skb*.
|
|
* The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
|
|
* indicates that the tunnel is based on IPv6 protocol instead of
|
|
* IPv4.
|
|
*
|
|
* The **struct bpf_tunnel_key** is an object that generalizes the
|
|
* principal parameters used by various tunneling protocols into a
|
|
* single struct. This way, it can be used to easily make a
|
|
* decision based on the contents of the encapsulation header,
|
|
* "summarized" in this struct. In particular, it holds the IP
|
|
* address of the remote end (IPv4 or IPv6, depending on the case)
|
|
* in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
|
|
* this struct exposes the *key*\ **->tunnel_id**, which is
|
|
* generally mapped to a VNI (Virtual Network Identifier), making
|
|
* it programmable together with the **bpf_skb_set_tunnel_key**\
|
|
* () helper.
|
|
*
|
|
* Let's imagine that the following code is part of a program
|
|
* attached to the TC ingress interface, on one end of a GRE
|
|
* tunnel, and is supposed to filter out all messages coming from
|
|
* remote ends with IPv4 address other than 10.0.0.1:
|
|
*
|
|
* ::
|
|
*
|
|
* int ret;
|
|
* struct bpf_tunnel_key key = {};
|
|
*
|
|
* ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
|
|
* if (ret < 0)
|
|
* return TC_ACT_SHOT; // drop packet
|
|
*
|
|
* if (key.remote_ipv4 != 0x0a000001)
|
|
* return TC_ACT_SHOT; // drop packet
|
|
*
|
|
* return TC_ACT_OK; // accept packet
|
|
*
|
|
* This interface can also be used with all encapsulation devices
|
|
* that can operate in "collect metadata" mode: instead of having
|
|
* one network device per specific configuration, the "collect
|
|
* metadata" mode only requires a single device where the
|
|
* configuration can be extracted from this helper.
|
|
*
|
|
* This can be used together with various tunnels such as VXLan,
|
|
* Geneve, GRE or IP in IP (IPIP).
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
|
|
* Description
|
|
* Populate tunnel metadata for packet associated to *skb.* The
|
|
* tunnel metadata is set to the contents of *key*, of *size*. The
|
|
* *flags* can be set to a combination of the following values:
|
|
*
|
|
* **BPF_F_TUNINFO_IPV6**
|
|
* Indicate that the tunnel is based on IPv6 protocol
|
|
* instead of IPv4.
|
|
* **BPF_F_ZERO_CSUM_TX**
|
|
* For IPv4 packets, add a flag to tunnel metadata
|
|
* indicating that checksum computation should be skipped
|
|
* and checksum set to zeroes.
|
|
* **BPF_F_DONT_FRAGMENT**
|
|
* Add a flag to tunnel metadata indicating that the
|
|
* packet should not be fragmented.
|
|
* **BPF_F_SEQ_NUMBER**
|
|
* Add a flag to tunnel metadata indicating that a
|
|
* sequence number should be added to tunnel header before
|
|
* sending the packet. This flag was added for GRE
|
|
* encapsulation, but might be used with other protocols
|
|
* as well in the future.
|
|
*
|
|
* Here is a typical usage on the transmit path:
|
|
*
|
|
* ::
|
|
*
|
|
* struct bpf_tunnel_key key;
|
|
* populate key ...
|
|
* bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
|
|
* bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
|
|
*
|
|
* See also the description of the **bpf_skb_get_tunnel_key**\ ()
|
|
* helper for additional information.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
|
|
* Description
|
|
* Read the value of a perf event counter. This helper relies on a
|
|
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
|
|
* the perf event counter is selected when *map* is updated with
|
|
* perf event file descriptors. The *map* is an array whose size
|
|
* is the number of available CPUs, and each cell contains a value
|
|
* relative to one CPU. The value to retrieve is indicated by
|
|
* *flags*, that contains the index of the CPU to look up, masked
|
|
* with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
|
|
* **BPF_F_CURRENT_CPU** to indicate that the value for the
|
|
* current CPU should be retrieved.
|
|
*
|
|
* Note that before Linux 4.13, only hardware perf event can be
|
|
* retrieved.
|
|
*
|
|
* Also, be aware that the newer helper
|
|
* **bpf_perf_event_read_value**\ () is recommended over
|
|
* **bpf_perf_event_read**\ () in general. The latter has some ABI
|
|
* quirks where error and counter value are used as a return code
|
|
* (which is wrong to do since ranges may overlap). This issue is
|
|
* fixed with **bpf_perf_event_read_value**\ (), which at the same
|
|
* time provides more features over the **bpf_perf_event_read**\
|
|
* () interface. Please refer to the description of
|
|
* **bpf_perf_event_read_value**\ () for details.
|
|
* Return
|
|
* The value of the perf event counter read from the map, or a
|
|
* negative error code in case of failure.
|
|
*
|
|
* int bpf_redirect(u32 ifindex, u64 flags)
|
|
* Description
|
|
* Redirect the packet to another net device of index *ifindex*.
|
|
* This helper is somewhat similar to **bpf_clone_redirect**\
|
|
* (), except that the packet is not cloned, which provides
|
|
* increased performance.
|
|
*
|
|
* Except for XDP, both ingress and egress interfaces can be used
|
|
* for redirection. The **BPF_F_INGRESS** value in *flags* is used
|
|
* to make the distinction (ingress path is selected if the flag
|
|
* is present, egress path otherwise). Currently, XDP only
|
|
* supports redirection to the egress interface, and accepts no
|
|
* flag at all.
|
|
*
|
|
* The same effect can be attained with the more generic
|
|
* **bpf_redirect_map**\ (), which requires specific maps to be
|
|
* used but offers better performance.
|
|
* Return
|
|
* For XDP, the helper returns **XDP_REDIRECT** on success or
|
|
* **XDP_ABORTED** on error. For other program types, the values
|
|
* are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
|
|
* error.
|
|
*
|
|
* u32 bpf_get_route_realm(struct sk_buff *skb)
|
|
* Description
|
|
* Retrieve the realm or the route, that is to say the
|
|
* **tclassid** field of the destination for the *skb*. The
|
|
* indentifier retrieved is a user-provided tag, similar to the
|
|
* one used with the net_cls cgroup (see description for
|
|
* **bpf_get_cgroup_classid**\ () helper), but here this tag is
|
|
* held by a route (a destination entry), not by a task.
|
|
*
|
|
* Retrieving this identifier works with the clsact TC egress hook
|
|
* (see also **tc-bpf(8)**), or alternatively on conventional
|
|
* classful egress qdiscs, but not on TC ingress path. In case of
|
|
* clsact TC egress hook, this has the advantage that, internally,
|
|
* the destination entry has not been dropped yet in the transmit
|
|
* path. Therefore, the destination entry does not need to be
|
|
* artificially held via **netif_keep_dst**\ () for a classful
|
|
* qdisc until the *skb* is freed.
|
|
*
|
|
* This helper is available only if the kernel was compiled with
|
|
* **CONFIG_IP_ROUTE_CLASSID** configuration option.
|
|
* Return
|
|
* The realm of the route for the packet associated to *skb*, or 0
|
|
* if none was found.
|
|
*
|
|
* int bpf_perf_event_output(struct pt_reg *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
|
|
* Description
|
|
* Write raw *data* blob into a special BPF perf event held by
|
|
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
|
|
* event must have the following attributes: **PERF_SAMPLE_RAW**
|
|
* as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
|
|
* **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
|
|
*
|
|
* The *flags* are used to indicate the index in *map* for which
|
|
* the value must be put, masked with **BPF_F_INDEX_MASK**.
|
|
* Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
|
|
* to indicate that the index of the current CPU core should be
|
|
* used.
|
|
*
|
|
* The value to write, of *size*, is passed through eBPF stack and
|
|
* pointed by *data*.
|
|
*
|
|
* The context of the program *ctx* needs also be passed to the
|
|
* helper.
|
|
*
|
|
* On user space, a program willing to read the values needs to
|
|
* call **perf_event_open**\ () on the perf event (either for
|
|
* one or for all CPUs) and to store the file descriptor into the
|
|
* *map*. This must be done before the eBPF program can send data
|
|
* into it. An example is available in file
|
|
* *samples/bpf/trace_output_user.c* in the Linux kernel source
|
|
* tree (the eBPF program counterpart is in
|
|
* *samples/bpf/trace_output_kern.c*).
|
|
*
|
|
* **bpf_perf_event_output**\ () achieves better performance
|
|
* than **bpf_trace_printk**\ () for sharing data with user
|
|
* space, and is much better suitable for streaming data from eBPF
|
|
* programs.
|
|
*
|
|
* Note that this helper is not restricted to tracing use cases
|
|
* and can be used with programs attached to TC or XDP as well,
|
|
* where it allows for passing data to user space listeners. Data
|
|
* can be:
|
|
*
|
|
* * Only custom structs,
|
|
* * Only the packet payload, or
|
|
* * A combination of both.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_load_bytes(const struct sk_buff *skb, u32 offset, void *to, u32 len)
|
|
* Description
|
|
* This helper was provided as an easy way to load data from a
|
|
* packet. It can be used to load *len* bytes from *offset* from
|
|
* the packet associated to *skb*, into the buffer pointed by
|
|
* *to*.
|
|
*
|
|
* Since Linux 4.7, usage of this helper has mostly been replaced
|
|
* by "direct packet access", enabling packet data to be
|
|
* manipulated with *skb*\ **->data** and *skb*\ **->data_end**
|
|
* pointing respectively to the first byte of packet data and to
|
|
* the byte after the last byte of packet data. However, it
|
|
* remains useful if one wishes to read large quantities of data
|
|
* at once from a packet into the eBPF stack.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_get_stackid(struct pt_reg *ctx, struct bpf_map *map, u64 flags)
|
|
* Description
|
|
* Walk a user or a kernel stack and return its id. To achieve
|
|
* this, the helper needs *ctx*, which is a pointer to the context
|
|
* on which the tracing program is executed, and a pointer to a
|
|
* *map* of type **BPF_MAP_TYPE_STACK_TRACE**.
|
|
*
|
|
* The last argument, *flags*, holds the number of stack frames to
|
|
* skip (from 0 to 255), masked with
|
|
* **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
|
|
* a combination of the following flags:
|
|
*
|
|
* **BPF_F_USER_STACK**
|
|
* Collect a user space stack instead of a kernel stack.
|
|
* **BPF_F_FAST_STACK_CMP**
|
|
* Compare stacks by hash only.
|
|
* **BPF_F_REUSE_STACKID**
|
|
* If two different stacks hash into the same *stackid*,
|
|
* discard the old one.
|
|
*
|
|
* The stack id retrieved is a 32 bit long integer handle which
|
|
* can be further combined with other data (including other stack
|
|
* ids) and used as a key into maps. This can be useful for
|
|
* generating a variety of graphs (such as flame graphs or off-cpu
|
|
* graphs).
|
|
*
|
|
* For walking a stack, this helper is an improvement over
|
|
* **bpf_probe_read**\ (), which can be used with unrolled loops
|
|
* but is not efficient and consumes a lot of eBPF instructions.
|
|
* Instead, **bpf_get_stackid**\ () can collect up to
|
|
* **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
|
|
* this limit can be controlled with the **sysctl** program, and
|
|
* that it should be manually increased in order to profile long
|
|
* user stacks (such as stacks for Java programs). To do so, use:
|
|
*
|
|
* ::
|
|
*
|
|
* # sysctl kernel.perf_event_max_stack=<new value>
|
|
* Return
|
|
* The positive or null stack id on success, or a negative error
|
|
* in case of failure.
|
|
*
|
|
* s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed)
|
|
* Description
|
|
* Compute a checksum difference, from the raw buffer pointed by
|
|
* *from*, of length *from_size* (that must be a multiple of 4),
|
|
* towards the raw buffer pointed by *to*, of size *to_size*
|
|
* (same remark). An optional *seed* can be added to the value
|
|
* (this can be cascaded, the seed may come from a previous call
|
|
* to the helper).
|
|
*
|
|
* This is flexible enough to be used in several ways:
|
|
*
|
|
* * With *from_size* == 0, *to_size* > 0 and *seed* set to
|
|
* checksum, it can be used when pushing new data.
|
|
* * With *from_size* > 0, *to_size* == 0 and *seed* set to
|
|
* checksum, it can be used when removing data from a packet.
|
|
* * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
|
|
* can be used to compute a diff. Note that *from_size* and
|
|
* *to_size* do not need to be equal.
|
|
*
|
|
* This helper can be used in combination with
|
|
* **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
|
|
* which one can feed in the difference computed with
|
|
* **bpf_csum_diff**\ ().
|
|
* Return
|
|
* The checksum result, or a negative error code in case of
|
|
* failure.
|
|
*
|
|
* int bpf_skb_get_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size)
|
|
* Description
|
|
* Retrieve tunnel options metadata for the packet associated to
|
|
* *skb*, and store the raw tunnel option data to the buffer *opt*
|
|
* of *size*.
|
|
*
|
|
* This helper can be used with encapsulation devices that can
|
|
* operate in "collect metadata" mode (please refer to the related
|
|
* note in the description of **bpf_skb_get_tunnel_key**\ () for
|
|
* more details). A particular example where this can be used is
|
|
* in combination with the Geneve encapsulation protocol, where it
|
|
* allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
|
|
* and retrieving arbitrary TLVs (Type-Length-Value headers) from
|
|
* the eBPF program. This allows for full customization of these
|
|
* headers.
|
|
* Return
|
|
* The size of the option data retrieved.
|
|
*
|
|
* int bpf_skb_set_tunnel_opt(struct sk_buff *skb, u8 *opt, u32 size)
|
|
* Description
|
|
* Set tunnel options metadata for the packet associated to *skb*
|
|
* to the option data contained in the raw buffer *opt* of *size*.
|
|
*
|
|
* See also the description of the **bpf_skb_get_tunnel_opt**\ ()
|
|
* helper for additional information.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
|
|
* Description
|
|
* Change the protocol of the *skb* to *proto*. Currently
|
|
* supported are transition from IPv4 to IPv6, and from IPv6 to
|
|
* IPv4. The helper takes care of the groundwork for the
|
|
* transition, including resizing the socket buffer. The eBPF
|
|
* program is expected to fill the new headers, if any, via
|
|
* **skb_store_bytes**\ () and to recompute the checksums with
|
|
* **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
|
|
* (). The main case for this helper is to perform NAT64
|
|
* operations out of an eBPF program.
|
|
*
|
|
* Internally, the GSO type is marked as dodgy so that headers are
|
|
* checked and segments are recalculated by the GSO/GRO engine.
|
|
* The size for GSO target is adapted as well.
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_change_type(struct sk_buff *skb, u32 type)
|
|
* Description
|
|
* Change the packet type for the packet associated to *skb*. This
|
|
* comes down to setting *skb*\ **->pkt_type** to *type*, except
|
|
* the eBPF program does not have a write access to *skb*\
|
|
* **->pkt_type** beside this helper. Using a helper here allows
|
|
* for graceful handling of errors.
|
|
*
|
|
* The major use case is to change incoming *skb*s to
|
|
* **PACKET_HOST** in a programmatic way instead of having to
|
|
* recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
|
|
* example.
|
|
*
|
|
* Note that *type* only allows certain values. At this time, they
|
|
* are:
|
|
*
|
|
* **PACKET_HOST**
|
|
* Packet is for us.
|
|
* **PACKET_BROADCAST**
|
|
* Send packet to all.
|
|
* **PACKET_MULTICAST**
|
|
* Send packet to group.
|
|
* **PACKET_OTHERHOST**
|
|
* Send packet to someone else.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
|
|
* Description
|
|
* Check whether *skb* is a descendant of the cgroup2 held by
|
|
* *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
|
|
* Return
|
|
* The return value depends on the result of the test, and can be:
|
|
*
|
|
* * 0, if the *skb* failed the cgroup2 descendant test.
|
|
* * 1, if the *skb* succeeded the cgroup2 descendant test.
|
|
* * A negative error code, if an error occurred.
|
|
*
|
|
* u32 bpf_get_hash_recalc(struct sk_buff *skb)
|
|
* Description
|
|
* Retrieve the hash of the packet, *skb*\ **->hash**. If it is
|
|
* not set, in particular if the hash was cleared due to mangling,
|
|
* recompute this hash. Later accesses to the hash can be done
|
|
* directly with *skb*\ **->hash**.
|
|
*
|
|
* Calling **bpf_set_hash_invalid**\ (), changing a packet
|
|
* prototype with **bpf_skb_change_proto**\ (), or calling
|
|
* **bpf_skb_store_bytes**\ () with the
|
|
* **BPF_F_INVALIDATE_HASH** are actions susceptible to clear
|
|
* the hash and to trigger a new computation for the next call to
|
|
* **bpf_get_hash_recalc**\ ().
|
|
* Return
|
|
* The 32-bit hash.
|
|
*
|
|
* u64 bpf_get_current_task(void)
|
|
* Return
|
|
* A pointer to the current task struct.
|
|
*
|
|
* int bpf_probe_write_user(void *dst, const void *src, u32 len)
|
|
* Description
|
|
* Attempt in a safe way to write *len* bytes from the buffer
|
|
* *src* to *dst* in memory. It only works for threads that are in
|
|
* user context, and *dst* must be a valid user space address.
|
|
*
|
|
* This helper should not be used to implement any kind of
|
|
* security mechanism because of TOC-TOU attacks, but rather to
|
|
* debug, divert, and manipulate execution of semi-cooperative
|
|
* processes.
|
|
*
|
|
* Keep in mind that this feature is meant for experiments, and it
|
|
* has a risk of crashing the system and running programs.
|
|
* Therefore, when an eBPF program using this helper is attached,
|
|
* a warning including PID and process name is printed to kernel
|
|
* logs.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
|
|
* Description
|
|
* Check whether the probe is being run is the context of a given
|
|
* subset of the cgroup2 hierarchy. The cgroup2 to test is held by
|
|
* *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
|
|
* Return
|
|
* The return value depends on the result of the test, and can be:
|
|
*
|
|
* * 0, if the *skb* task belongs to the cgroup2.
|
|
* * 1, if the *skb* task does not belong to the cgroup2.
|
|
* * A negative error code, if an error occurred.
|
|
*
|
|
* int bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
|
|
* Description
|
|
* Resize (trim or grow) the packet associated to *skb* to the
|
|
* new *len*. The *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* The basic idea is that the helper performs the needed work to
|
|
* change the size of the packet, then the eBPF program rewrites
|
|
* the rest via helpers like **bpf_skb_store_bytes**\ (),
|
|
* **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
|
|
* and others. This helper is a slow path utility intended for
|
|
* replies with control messages. And because it is targeted for
|
|
* slow path, the helper itself can afford to be slow: it
|
|
* implicitly linearizes, unclones and drops offloads from the
|
|
* *skb*.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_pull_data(struct sk_buff *skb, u32 len)
|
|
* Description
|
|
* Pull in non-linear data in case the *skb* is non-linear and not
|
|
* all of *len* are part of the linear section. Make *len* bytes
|
|
* from *skb* readable and writable. If a zero value is passed for
|
|
* *len*, then the whole length of the *skb* is pulled.
|
|
*
|
|
* This helper is only needed for reading and writing with direct
|
|
* packet access.
|
|
*
|
|
* For direct packet access, testing that offsets to access
|
|
* are within packet boundaries (test on *skb*\ **->data_end**) is
|
|
* susceptible to fail if offsets are invalid, or if the requested
|
|
* data is in non-linear parts of the *skb*. On failure the
|
|
* program can just bail out, or in the case of a non-linear
|
|
* buffer, use a helper to make the data available. The
|
|
* **bpf_skb_load_bytes**\ () helper is a first solution to access
|
|
* the data. Another one consists in using **bpf_skb_pull_data**
|
|
* to pull in once the non-linear parts, then retesting and
|
|
* eventually access the data.
|
|
*
|
|
* At the same time, this also makes sure the *skb* is uncloned,
|
|
* which is a necessary condition for direct write. As this needs
|
|
* to be an invariant for the write part only, the verifier
|
|
* detects writes and adds a prologue that is calling
|
|
* **bpf_skb_pull_data()** to effectively unclone the *skb* from
|
|
* the very beginning in case it is indeed cloned.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
|
|
* Description
|
|
* Add the checksum *csum* into *skb*\ **->csum** in case the
|
|
* driver has supplied a checksum for the entire packet into that
|
|
* field. Return an error otherwise. This helper is intended to be
|
|
* used in combination with **bpf_csum_diff**\ (), in particular
|
|
* when the checksum needs to be updated after data has been
|
|
* written into the packet through direct packet access.
|
|
* Return
|
|
* The checksum on success, or a negative error code in case of
|
|
* failure.
|
|
*
|
|
* void bpf_set_hash_invalid(struct sk_buff *skb)
|
|
* Description
|
|
* Invalidate the current *skb*\ **->hash**. It can be used after
|
|
* mangling on headers through direct packet access, in order to
|
|
* indicate that the hash is outdated and to trigger a
|
|
* recalculation the next time the kernel tries to access this
|
|
* hash or when the **bpf_get_hash_recalc**\ () helper is called.
|
|
*
|
|
* int bpf_get_numa_node_id(void)
|
|
* Description
|
|
* Return the id of the current NUMA node. The primary use case
|
|
* for this helper is the selection of sockets for the local NUMA
|
|
* node, when the program is attached to sockets using the
|
|
* **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
|
|
* but the helper is also available to other eBPF program types,
|
|
* similarly to **bpf_get_smp_processor_id**\ ().
|
|
* Return
|
|
* The id of current NUMA node.
|
|
*
|
|
* int bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
|
|
* Description
|
|
* Grows headroom of packet associated to *skb* and adjusts the
|
|
* offset of the MAC header accordingly, adding *len* bytes of
|
|
* space. It automatically extends and reallocates memory as
|
|
* required.
|
|
*
|
|
* This helper can be used on a layer 3 *skb* to push a MAC header
|
|
* for redirection into a layer 2 device.
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
|
|
* Description
|
|
* Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
|
|
* it is possible to use a negative value for *delta*. This helper
|
|
* can be used to prepare the packet for pushing or popping
|
|
* headers.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_probe_read_str(void *dst, int size, const void *unsafe_ptr)
|
|
* Description
|
|
* Copy a NUL terminated string from an unsafe address
|
|
* *unsafe_ptr* to *dst*. The *size* should include the
|
|
* terminating NUL byte. In case the string length is smaller than
|
|
* *size*, the target is not padded with further NUL bytes. If the
|
|
* string length is larger than *size*, just *size*-1 bytes are
|
|
* copied and the last byte is set to NUL.
|
|
*
|
|
* On success, the length of the copied string is returned. This
|
|
* makes this helper useful in tracing programs for reading
|
|
* strings, and more importantly to get its length at runtime. See
|
|
* the following snippet:
|
|
*
|
|
* ::
|
|
*
|
|
* SEC("kprobe/sys_open")
|
|
* void bpf_sys_open(struct pt_regs *ctx)
|
|
* {
|
|
* char buf[PATHLEN]; // PATHLEN is defined to 256
|
|
* int res = bpf_probe_read_str(buf, sizeof(buf),
|
|
* ctx->di);
|
|
*
|
|
* // Consume buf, for example push it to
|
|
* // userspace via bpf_perf_event_output(); we
|
|
* // can use res (the string length) as event
|
|
* // size, after checking its boundaries.
|
|
* }
|
|
*
|
|
* In comparison, using **bpf_probe_read()** helper here instead
|
|
* to read the string would require to estimate the length at
|
|
* compile time, and would often result in copying more memory
|
|
* than necessary.
|
|
*
|
|
* Another useful use case is when parsing individual process
|
|
* arguments or individual environment variables navigating
|
|
* *current*\ **->mm->arg_start** and *current*\
|
|
* **->mm->env_start**: using this helper and the return value,
|
|
* one can quickly iterate at the right offset of the memory area.
|
|
* Return
|
|
* On success, the strictly positive length of the string,
|
|
* including the trailing NUL character. On error, a negative
|
|
* value.
|
|
*
|
|
* u64 bpf_get_socket_cookie(struct sk_buff *skb)
|
|
* Description
|
|
* If the **struct sk_buff** pointed by *skb* has a known socket,
|
|
* retrieve the cookie (generated by the kernel) of this socket.
|
|
* If no cookie has been set yet, generate a new cookie. Once
|
|
* generated, the socket cookie remains stable for the life of the
|
|
* socket. This helper can be useful for monitoring per socket
|
|
* networking traffic statistics as it provides a unique socket
|
|
* identifier per namespace.
|
|
* Return
|
|
* A 8-byte long non-decreasing number on success, or 0 if the
|
|
* socket field is missing inside *skb*.
|
|
*
|
|
* u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
|
|
* Description
|
|
* Equivalent to bpf_get_socket_cookie() helper that accepts
|
|
* *skb*, but gets socket from **struct bpf_sock_addr** contex.
|
|
* Return
|
|
* A 8-byte long non-decreasing number.
|
|
*
|
|
* u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
|
|
* Description
|
|
* Equivalent to bpf_get_socket_cookie() helper that accepts
|
|
* *skb*, but gets socket from **struct bpf_sock_ops** contex.
|
|
* Return
|
|
* A 8-byte long non-decreasing number.
|
|
*
|
|
* u32 bpf_get_socket_uid(struct sk_buff *skb)
|
|
* Return
|
|
* The owner UID of the socket associated to *skb*. If the socket
|
|
* is **NULL**, or if it is not a full socket (i.e. if it is a
|
|
* time-wait or a request socket instead), **overflowuid** value
|
|
* is returned (note that **overflowuid** might also be the actual
|
|
* UID value for the socket).
|
|
*
|
|
* u32 bpf_set_hash(struct sk_buff *skb, u32 hash)
|
|
* Description
|
|
* Set the full hash for *skb* (set the field *skb*\ **->hash**)
|
|
* to value *hash*.
|
|
* Return
|
|
* 0
|
|
*
|
|
* int bpf_setsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen)
|
|
* Description
|
|
* Emulate a call to **setsockopt()** on the socket associated to
|
|
* *bpf_socket*, which must be a full socket. The *level* at
|
|
* which the option resides and the name *optname* of the option
|
|
* must be specified, see **setsockopt(2)** for more information.
|
|
* The option value of length *optlen* is pointed by *optval*.
|
|
*
|
|
* This helper actually implements a subset of **setsockopt()**.
|
|
* It supports the following *level*\ s:
|
|
*
|
|
* * **SOL_SOCKET**, which supports the following *optname*\ s:
|
|
* **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
|
|
* **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.
|
|
* * **IPPROTO_TCP**, which supports the following *optname*\ s:
|
|
* **TCP_CONGESTION**, **TCP_BPF_IW**,
|
|
* **TCP_BPF_SNDCWND_CLAMP**.
|
|
* * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
|
|
* * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags)
|
|
* Description
|
|
* Grow or shrink the room for data in the packet associated to
|
|
* *skb* by *len_diff*, and according to the selected *mode*.
|
|
*
|
|
* There is a single supported mode at this time:
|
|
*
|
|
* * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
|
|
* (room space is added or removed below the layer 3 header).
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags)
|
|
* Description
|
|
* Redirect the packet to the endpoint referenced by *map* at
|
|
* index *key*. Depending on its type, this *map* can contain
|
|
* references to net devices (for forwarding packets through other
|
|
* ports), or to CPUs (for redirecting XDP frames to another CPU;
|
|
* but this is only implemented for native XDP (with driver
|
|
* support) as of this writing).
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* When used to redirect packets to net devices, this helper
|
|
* provides a high performance increase over **bpf_redirect**\ ().
|
|
* This is due to various implementation details of the underlying
|
|
* mechanisms, one of which is the fact that **bpf_redirect_map**\
|
|
* () tries to send packet as a "bulk" to the device.
|
|
* Return
|
|
* **XDP_REDIRECT** on success, or **XDP_ABORTED** on error.
|
|
*
|
|
* int bpf_sk_redirect_map(struct bpf_map *map, u32 key, u64 flags)
|
|
* Description
|
|
* Redirect the packet to the socket referenced by *map* (of type
|
|
* **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
|
|
* egress interfaces can be used for redirection. The
|
|
* **BPF_F_INGRESS** value in *flags* is used to make the
|
|
* distinction (ingress path is selected if the flag is present,
|
|
* egress path otherwise). This is the only flag supported for now.
|
|
* Return
|
|
* **SK_PASS** on success, or **SK_DROP** on error.
|
|
*
|
|
* int bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
|
|
* Description
|
|
* Add an entry to, or update a *map* referencing sockets. The
|
|
* *skops* is used as a new value for the entry associated to
|
|
* *key*. *flags* is one of:
|
|
*
|
|
* **BPF_NOEXIST**
|
|
* The entry for *key* must not exist in the map.
|
|
* **BPF_EXIST**
|
|
* The entry for *key* must already exist in the map.
|
|
* **BPF_ANY**
|
|
* No condition on the existence of the entry for *key*.
|
|
*
|
|
* If the *map* has eBPF programs (parser and verdict), those will
|
|
* be inherited by the socket being added. If the socket is
|
|
* already attached to eBPF programs, this results in an error.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
|
|
* Description
|
|
* Adjust the address pointed by *xdp_md*\ **->data_meta** by
|
|
* *delta* (which can be positive or negative). Note that this
|
|
* operation modifies the address stored in *xdp_md*\ **->data**,
|
|
* so the latter must be loaded only after the helper has been
|
|
* called.
|
|
*
|
|
* The use of *xdp_md*\ **->data_meta** is optional and programs
|
|
* are not required to use it. The rationale is that when the
|
|
* packet is processed with XDP (e.g. as DoS filter), it is
|
|
* possible to push further meta data along with it before passing
|
|
* to the stack, and to give the guarantee that an ingress eBPF
|
|
* program attached as a TC classifier on the same device can pick
|
|
* this up for further post-processing. Since TC works with socket
|
|
* buffers, it remains possible to set from XDP the **mark** or
|
|
* **priority** pointers, or other pointers for the socket buffer.
|
|
* Having this scratch space generic and programmable allows for
|
|
* more flexibility as the user is free to store whatever meta
|
|
* data they need.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size)
|
|
* Description
|
|
* Read the value of a perf event counter, and store it into *buf*
|
|
* of size *buf_size*. This helper relies on a *map* of type
|
|
* **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
|
|
* counter is selected when *map* is updated with perf event file
|
|
* descriptors. The *map* is an array whose size is the number of
|
|
* available CPUs, and each cell contains a value relative to one
|
|
* CPU. The value to retrieve is indicated by *flags*, that
|
|
* contains the index of the CPU to look up, masked with
|
|
* **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
|
|
* **BPF_F_CURRENT_CPU** to indicate that the value for the
|
|
* current CPU should be retrieved.
|
|
*
|
|
* This helper behaves in a way close to
|
|
* **bpf_perf_event_read**\ () helper, save that instead of
|
|
* just returning the value observed, it fills the *buf*
|
|
* structure. This allows for additional data to be retrieved: in
|
|
* particular, the enabled and running times (in *buf*\
|
|
* **->enabled** and *buf*\ **->running**, respectively) are
|
|
* copied. In general, **bpf_perf_event_read_value**\ () is
|
|
* recommended over **bpf_perf_event_read**\ (), which has some
|
|
* ABI issues and provides fewer functionalities.
|
|
*
|
|
* These values are interesting, because hardware PMU (Performance
|
|
* Monitoring Unit) counters are limited resources. When there are
|
|
* more PMU based perf events opened than available counters,
|
|
* kernel will multiplex these events so each event gets certain
|
|
* percentage (but not all) of the PMU time. In case that
|
|
* multiplexing happens, the number of samples or counter value
|
|
* will not reflect the case compared to when no multiplexing
|
|
* occurs. This makes comparison between different runs difficult.
|
|
* Typically, the counter value should be normalized before
|
|
* comparing to other experiments. The usual normalization is done
|
|
* as follows.
|
|
*
|
|
* ::
|
|
*
|
|
* normalized_counter = counter * t_enabled / t_running
|
|
*
|
|
* Where t_enabled is the time enabled for event and t_running is
|
|
* the time running for event since last normalization. The
|
|
* enabled and running times are accumulated since the perf event
|
|
* open. To achieve scaling factor between two invocations of an
|
|
* eBPF program, users can can use CPU id as the key (which is
|
|
* typical for perf array usage model) to remember the previous
|
|
* value and do the calculation inside the eBPF program.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size)
|
|
* Description
|
|
* For en eBPF program attached to a perf event, retrieve the
|
|
* value of the event counter associated to *ctx* and store it in
|
|
* the structure pointed by *buf* and of size *buf_size*. Enabled
|
|
* and running times are also stored in the structure (see
|
|
* description of helper **bpf_perf_event_read_value**\ () for
|
|
* more details).
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_getsockopt(struct bpf_sock_ops *bpf_socket, int level, int optname, char *optval, int optlen)
|
|
* Description
|
|
* Emulate a call to **getsockopt()** on the socket associated to
|
|
* *bpf_socket*, which must be a full socket. The *level* at
|
|
* which the option resides and the name *optname* of the option
|
|
* must be specified, see **getsockopt(2)** for more information.
|
|
* The retrieved value is stored in the structure pointed by
|
|
* *opval* and of length *optlen*.
|
|
*
|
|
* This helper actually implements a subset of **getsockopt()**.
|
|
* It supports the following *level*\ s:
|
|
*
|
|
* * **IPPROTO_TCP**, which supports *optname*
|
|
* **TCP_CONGESTION**.
|
|
* * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
|
|
* * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_override_return(struct pt_reg *regs, u64 rc)
|
|
* Description
|
|
* Used for error injection, this helper uses kprobes to override
|
|
* the return value of the probed function, and to set it to *rc*.
|
|
* The first argument is the context *regs* on which the kprobe
|
|
* works.
|
|
*
|
|
* This helper works by setting setting the PC (program counter)
|
|
* to an override function which is run in place of the original
|
|
* probed function. This means the probed function is not run at
|
|
* all. The replacement function just returns with the required
|
|
* value.
|
|
*
|
|
* This helper has security implications, and thus is subject to
|
|
* restrictions. It is only available if the kernel was compiled
|
|
* with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
|
|
* option, and in this case it only works on functions tagged with
|
|
* **ALLOW_ERROR_INJECTION** in the kernel code.
|
|
*
|
|
* Also, the helper is only available for the architectures having
|
|
* the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
|
|
* x86 architecture is the only one to support this feature.
|
|
* Return
|
|
* 0
|
|
*
|
|
* int bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
|
|
* Description
|
|
* Attempt to set the value of the **bpf_sock_ops_cb_flags** field
|
|
* for the full TCP socket associated to *bpf_sock_ops* to
|
|
* *argval*.
|
|
*
|
|
* The primary use of this field is to determine if there should
|
|
* be calls to eBPF programs of type
|
|
* **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
|
|
* code. A program of the same type can change its value, per
|
|
* connection and as necessary, when the connection is
|
|
* established. This field is directly accessible for reading, but
|
|
* this helper must be used for updates in order to return an
|
|
* error if an eBPF program tries to set a callback that is not
|
|
* supported in the current kernel.
|
|
*
|
|
* The supported callback values that *argval* can combine are:
|
|
*
|
|
* * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
|
|
* * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
|
|
* * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
|
|
*
|
|
* Here are some examples of where one could call such eBPF
|
|
* program:
|
|
*
|
|
* * When RTO fires.
|
|
* * When a packet is retransmitted.
|
|
* * When the connection terminates.
|
|
* * When a packet is sent.
|
|
* * When a packet is received.
|
|
* Return
|
|
* Code **-EINVAL** if the socket is not a full TCP socket;
|
|
* otherwise, a positive number containing the bits that could not
|
|
* be set is returned (which comes down to 0 if all bits were set
|
|
* as required).
|
|
*
|
|
* int bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags)
|
|
* Description
|
|
* This helper is used in programs implementing policies at the
|
|
* socket level. If the message *msg* is allowed to pass (i.e. if
|
|
* the verdict eBPF program returns **SK_PASS**), redirect it to
|
|
* the socket referenced by *map* (of type
|
|
* **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
|
|
* egress interfaces can be used for redirection. The
|
|
* **BPF_F_INGRESS** value in *flags* is used to make the
|
|
* distinction (ingress path is selected if the flag is present,
|
|
* egress path otherwise). This is the only flag supported for now.
|
|
* Return
|
|
* **SK_PASS** on success, or **SK_DROP** on error.
|
|
*
|
|
* int bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
|
|
* Description
|
|
* For socket policies, apply the verdict of the eBPF program to
|
|
* the next *bytes* (number of bytes) of message *msg*.
|
|
*
|
|
* For example, this helper can be used in the following cases:
|
|
*
|
|
* * A single **sendmsg**\ () or **sendfile**\ () system call
|
|
* contains multiple logical messages that the eBPF program is
|
|
* supposed to read and for which it should apply a verdict.
|
|
* * An eBPF program only cares to read the first *bytes* of a
|
|
* *msg*. If the message has a large payload, then setting up
|
|
* and calling the eBPF program repeatedly for all bytes, even
|
|
* though the verdict is already known, would create unnecessary
|
|
* overhead.
|
|
*
|
|
* When called from within an eBPF program, the helper sets a
|
|
* counter internal to the BPF infrastructure, that is used to
|
|
* apply the last verdict to the next *bytes*. If *bytes* is
|
|
* smaller than the current data being processed from a
|
|
* **sendmsg**\ () or **sendfile**\ () system call, the first
|
|
* *bytes* will be sent and the eBPF program will be re-run with
|
|
* the pointer for start of data pointing to byte number *bytes*
|
|
* **+ 1**. If *bytes* is larger than the current data being
|
|
* processed, then the eBPF verdict will be applied to multiple
|
|
* **sendmsg**\ () or **sendfile**\ () calls until *bytes* are
|
|
* consumed.
|
|
*
|
|
* Note that if a socket closes with the internal counter holding
|
|
* a non-zero value, this is not a problem because data is not
|
|
* being buffered for *bytes* and is sent as it is received.
|
|
* Return
|
|
* 0
|
|
*
|
|
* int bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
|
|
* Description
|
|
* For socket policies, prevent the execution of the verdict eBPF
|
|
* program for message *msg* until *bytes* (byte number) have been
|
|
* accumulated.
|
|
*
|
|
* This can be used when one needs a specific number of bytes
|
|
* before a verdict can be assigned, even if the data spans
|
|
* multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
|
|
* case would be a user calling **sendmsg**\ () repeatedly with
|
|
* 1-byte long message segments. Obviously, this is bad for
|
|
* performance, but it is still valid. If the eBPF program needs
|
|
* *bytes* bytes to validate a header, this helper can be used to
|
|
* prevent the eBPF program to be called again until *bytes* have
|
|
* been accumulated.
|
|
* Return
|
|
* 0
|
|
*
|
|
* int bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
|
|
* Description
|
|
* For socket policies, pull in non-linear data from user space
|
|
* for *msg* and set pointers *msg*\ **->data** and *msg*\
|
|
* **->data_end** to *start* and *end* bytes offsets into *msg*,
|
|
* respectively.
|
|
*
|
|
* If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
|
|
* *msg* it can only parse data that the (**data**, **data_end**)
|
|
* pointers have already consumed. For **sendmsg**\ () hooks this
|
|
* is likely the first scatterlist element. But for calls relying
|
|
* on the **sendpage** handler (e.g. **sendfile**\ ()) this will
|
|
* be the range (**0**, **0**) because the data is shared with
|
|
* user space and by default the objective is to avoid allowing
|
|
* user space to modify data while (or after) eBPF verdict is
|
|
* being decided. This helper can be used to pull in data and to
|
|
* set the start and end pointer to given values. Data will be
|
|
* copied if necessary (i.e. if data was not linear and if start
|
|
* and end pointers do not point to the same chunk).
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len)
|
|
* Description
|
|
* Bind the socket associated to *ctx* to the address pointed by
|
|
* *addr*, of length *addr_len*. This allows for making outgoing
|
|
* connection from the desired IP address, which can be useful for
|
|
* example when all processes inside a cgroup should use one
|
|
* single IP address on a host that has multiple IP configured.
|
|
*
|
|
* This helper works for IPv4 and IPv6, TCP and UDP sockets. The
|
|
* domain (*addr*\ **->sa_family**) must be **AF_INET** (or
|
|
* **AF_INET6**). Looking for a free port to bind to can be
|
|
* expensive, therefore binding to port is not permitted by the
|
|
* helper: *addr*\ **->sin_port** (or **sin6_port**, respectively)
|
|
* must be set to zero.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
|
|
* Description
|
|
* Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
|
|
* only possible to shrink the packet as of this writing,
|
|
* therefore *delta* must be a negative integer.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags)
|
|
* Description
|
|
* Retrieve the XFRM state (IP transform framework, see also
|
|
* **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
|
|
*
|
|
* The retrieved value is stored in the **struct bpf_xfrm_state**
|
|
* pointed by *xfrm_state* and of length *size*.
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* This helper is available only if the kernel was compiled with
|
|
* **CONFIG_XFRM** configuration option.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_get_stack(struct pt_regs *regs, void *buf, u32 size, u64 flags)
|
|
* Description
|
|
* Return a user or a kernel stack in bpf program provided buffer.
|
|
* To achieve this, the helper needs *ctx*, which is a pointer
|
|
* to the context on which the tracing program is executed.
|
|
* To store the stacktrace, the bpf program provides *buf* with
|
|
* a nonnegative *size*.
|
|
*
|
|
* The last argument, *flags*, holds the number of stack frames to
|
|
* skip (from 0 to 255), masked with
|
|
* **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
|
|
* the following flags:
|
|
*
|
|
* **BPF_F_USER_STACK**
|
|
* Collect a user space stack instead of a kernel stack.
|
|
* **BPF_F_USER_BUILD_ID**
|
|
* Collect buildid+offset instead of ips for user stack,
|
|
* only valid if **BPF_F_USER_STACK** is also specified.
|
|
*
|
|
* **bpf_get_stack**\ () can collect up to
|
|
* **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
|
|
* to sufficient large buffer size. Note that
|
|
* this limit can be controlled with the **sysctl** program, and
|
|
* that it should be manually increased in order to profile long
|
|
* user stacks (such as stacks for Java programs). To do so, use:
|
|
*
|
|
* ::
|
|
*
|
|
* # sysctl kernel.perf_event_max_stack=<new value>
|
|
* Return
|
|
* A non-negative value equal to or less than *size* on success,
|
|
* or a negative error in case of failure.
|
|
*
|
|
* int bpf_skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header)
|
|
* Description
|
|
* This helper is similar to **bpf_skb_load_bytes**\ () in that
|
|
* it provides an easy way to load *len* bytes from *offset*
|
|
* from the packet associated to *skb*, into the buffer pointed
|
|
* by *to*. The difference to **bpf_skb_load_bytes**\ () is that
|
|
* a fifth argument *start_header* exists in order to select a
|
|
* base offset to start from. *start_header* can be one of:
|
|
*
|
|
* **BPF_HDR_START_MAC**
|
|
* Base offset to load data from is *skb*'s mac header.
|
|
* **BPF_HDR_START_NET**
|
|
* Base offset to load data from is *skb*'s network header.
|
|
*
|
|
* In general, "direct packet access" is the preferred method to
|
|
* access packet data, however, this helper is in particular useful
|
|
* in socket filters where *skb*\ **->data** does not always point
|
|
* to the start of the mac header and where "direct packet access"
|
|
* is not available.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
|
|
* Description
|
|
* Do FIB lookup in kernel tables using parameters in *params*.
|
|
* If lookup is successful and result shows packet is to be
|
|
* forwarded, the neighbor tables are searched for the nexthop.
|
|
* If successful (ie., FIB lookup shows forwarding and nexthop
|
|
* is resolved), the nexthop address is returned in ipv4_dst
|
|
* or ipv6_dst based on family, smac is set to mac address of
|
|
* egress device, dmac is set to nexthop mac address, rt_metric
|
|
* is set to metric from route (IPv4/IPv6 only), and ifindex
|
|
* is set to the device index of the nexthop from the FIB lookup.
|
|
*
|
|
* *plen* argument is the size of the passed in struct.
|
|
* *flags* argument can be a combination of one or more of the
|
|
* following values:
|
|
*
|
|
* **BPF_FIB_LOOKUP_DIRECT**
|
|
* Do a direct table lookup vs full lookup using FIB
|
|
* rules.
|
|
* **BPF_FIB_LOOKUP_OUTPUT**
|
|
* Perform lookup from an egress perspective (default is
|
|
* ingress).
|
|
*
|
|
* *ctx* is either **struct xdp_md** for XDP programs or
|
|
* **struct sk_buff** tc cls_act programs.
|
|
* Return
|
|
* * < 0 if any input argument is invalid
|
|
* * 0 on success (packet is forwarded, nexthop neighbor exists)
|
|
* * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
|
|
* packet is not forwarded or needs assist from full stack
|
|
*
|
|
* int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags)
|
|
* Description
|
|
* Add an entry to, or update a sockhash *map* referencing sockets.
|
|
* The *skops* is used as a new value for the entry associated to
|
|
* *key*. *flags* is one of:
|
|
*
|
|
* **BPF_NOEXIST**
|
|
* The entry for *key* must not exist in the map.
|
|
* **BPF_EXIST**
|
|
* The entry for *key* must already exist in the map.
|
|
* **BPF_ANY**
|
|
* No condition on the existence of the entry for *key*.
|
|
*
|
|
* If the *map* has eBPF programs (parser and verdict), those will
|
|
* be inherited by the socket being added. If the socket is
|
|
* already attached to eBPF programs, this results in an error.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
|
|
* Description
|
|
* This helper is used in programs implementing policies at the
|
|
* socket level. If the message *msg* is allowed to pass (i.e. if
|
|
* the verdict eBPF program returns **SK_PASS**), redirect it to
|
|
* the socket referenced by *map* (of type
|
|
* **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
|
|
* egress interfaces can be used for redirection. The
|
|
* **BPF_F_INGRESS** value in *flags* is used to make the
|
|
* distinction (ingress path is selected if the flag is present,
|
|
* egress path otherwise). This is the only flag supported for now.
|
|
* Return
|
|
* **SK_PASS** on success, or **SK_DROP** on error.
|
|
*
|
|
* int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
|
|
* Description
|
|
* This helper is used in programs implementing policies at the
|
|
* skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
|
|
* if the verdeict eBPF program returns **SK_PASS**), redirect it
|
|
* to the socket referenced by *map* (of type
|
|
* **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
|
|
* egress interfaces can be used for redirection. The
|
|
* **BPF_F_INGRESS** value in *flags* is used to make the
|
|
* distinction (ingress path is selected if the flag is present,
|
|
* egress otherwise). This is the only flag supported for now.
|
|
* Return
|
|
* **SK_PASS** on success, or **SK_DROP** on error.
|
|
*
|
|
* int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
|
|
* Description
|
|
* Encapsulate the packet associated to *skb* within a Layer 3
|
|
* protocol header. This header is provided in the buffer at
|
|
* address *hdr*, with *len* its size in bytes. *type* indicates
|
|
* the protocol of the header and can be one of:
|
|
*
|
|
* **BPF_LWT_ENCAP_SEG6**
|
|
* IPv6 encapsulation with Segment Routing Header
|
|
* (**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
|
|
* the IPv6 header is computed by the kernel.
|
|
* **BPF_LWT_ENCAP_SEG6_INLINE**
|
|
* Only works if *skb* contains an IPv6 packet. Insert a
|
|
* Segment Routing Header (**struct ipv6_sr_hdr**) inside
|
|
* the IPv6 header.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
|
|
* Description
|
|
* Store *len* bytes from address *from* into the packet
|
|
* associated to *skb*, at *offset*. Only the flags, tag and TLVs
|
|
* inside the outermost IPv6 Segment Routing Header can be
|
|
* modified through this helper.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
|
|
* Description
|
|
* Adjust the size allocated to TLVs in the outermost IPv6
|
|
* Segment Routing Header contained in the packet associated to
|
|
* *skb*, at position *offset* by *delta* bytes. Only offsets
|
|
* after the segments are accepted. *delta* can be as well
|
|
* positive (growing) as negative (shrinking).
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
|
|
* Description
|
|
* Apply an IPv6 Segment Routing action of type *action* to the
|
|
* packet associated to *skb*. Each action takes a parameter
|
|
* contained at address *param*, and of length *param_len* bytes.
|
|
* *action* can be one of:
|
|
*
|
|
* **SEG6_LOCAL_ACTION_END_X**
|
|
* End.X action: Endpoint with Layer-3 cross-connect.
|
|
* Type of *param*: **struct in6_addr**.
|
|
* **SEG6_LOCAL_ACTION_END_T**
|
|
* End.T action: Endpoint with specific IPv6 table lookup.
|
|
* Type of *param*: **int**.
|
|
* **SEG6_LOCAL_ACTION_END_B6**
|
|
* End.B6 action: Endpoint bound to an SRv6 policy.
|
|
* Type of param: **struct ipv6_sr_hdr**.
|
|
* **SEG6_LOCAL_ACTION_END_B6_ENCAP**
|
|
* End.B6.Encap action: Endpoint bound to an SRv6
|
|
* encapsulation policy.
|
|
* Type of param: **struct ipv6_sr_hdr**.
|
|
*
|
|
* A call to this helper is susceptible to change the underlaying
|
|
* packet buffer. Therefore, at load time, all checks on pointers
|
|
* previously done by the verifier are invalidated and must be
|
|
* performed again, if the helper is used in combination with
|
|
* direct packet access.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
|
|
* Description
|
|
* This helper is used in programs implementing IR decoding, to
|
|
* report a successfully decoded key press with *scancode*,
|
|
* *toggle* value in the given *protocol*. The scancode will be
|
|
* translated to a keycode using the rc keymap, and reported as
|
|
* an input key down event. After a period a key up event is
|
|
* generated. This period can be extended by calling either
|
|
* **bpf_rc_keydown**\ () again with the same values, or calling
|
|
* **bpf_rc_repeat**\ ().
|
|
*
|
|
* Some protocols include a toggle bit, in case the button was
|
|
* released and pressed again between consecutive scancodes.
|
|
*
|
|
* The *ctx* should point to the lirc sample as passed into
|
|
* the program.
|
|
*
|
|
* The *protocol* is the decoded protocol number (see
|
|
* **enum rc_proto** for some predefined values).
|
|
*
|
|
* This helper is only available is the kernel was compiled with
|
|
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
|
|
* "**y**".
|
|
* Return
|
|
* 0
|
|
*
|
|
* int bpf_rc_repeat(void *ctx)
|
|
* Description
|
|
* This helper is used in programs implementing IR decoding, to
|
|
* report a successfully decoded repeat key message. This delays
|
|
* the generation of a key up event for previously generated
|
|
* key down event.
|
|
*
|
|
* Some IR protocols like NEC have a special IR message for
|
|
* repeating last button, for when a button is held down.
|
|
*
|
|
* The *ctx* should point to the lirc sample as passed into
|
|
* the program.
|
|
*
|
|
* This helper is only available is the kernel was compiled with
|
|
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
|
|
* "**y**".
|
|
* Return
|
|
* 0
|
|
*
|
|
* uint64_t bpf_skb_cgroup_id(struct sk_buff *skb)
|
|
* Description
|
|
* Return the cgroup v2 id of the socket associated with the *skb*.
|
|
* This is roughly similar to the **bpf_get_cgroup_classid**\ ()
|
|
* helper for cgroup v1 by providing a tag resp. identifier that
|
|
* can be matched on or used for map lookups e.g. to implement
|
|
* policy. The cgroup v2 id of a given path in the hierarchy is
|
|
* exposed in user space through the f_handle API in order to get
|
|
* to the same 64-bit id.
|
|
*
|
|
* This helper can be used on TC egress path, but not on ingress,
|
|
* and is available only if the kernel was compiled with the
|
|
* **CONFIG_SOCK_CGROUP_DATA** configuration option.
|
|
* Return
|
|
* The id is returned or 0 in case the id could not be retrieved.
|
|
*
|
|
* u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level)
|
|
* Description
|
|
* Return id of cgroup v2 that is ancestor of cgroup associated
|
|
* with the *skb* at the *ancestor_level*. The root cgroup is at
|
|
* *ancestor_level* zero and each step down the hierarchy
|
|
* increments the level. If *ancestor_level* == level of cgroup
|
|
* associated with *skb*, then return value will be same as that
|
|
* of **bpf_skb_cgroup_id**\ ().
|
|
*
|
|
* The helper is useful to implement policies based on cgroups
|
|
* that are upper in hierarchy than immediate cgroup associated
|
|
* with *skb*.
|
|
*
|
|
* The format of returned id and helper limitations are same as in
|
|
* **bpf_skb_cgroup_id**\ ().
|
|
* Return
|
|
* The id is returned or 0 in case the id could not be retrieved.
|
|
*
|
|
* u64 bpf_get_current_cgroup_id(void)
|
|
* Return
|
|
* A 64-bit integer containing the current cgroup id based
|
|
* on the cgroup within which the current task is running.
|
|
*
|
|
* void* get_local_storage(void *map, u64 flags)
|
|
* Description
|
|
* Get the pointer to the local storage area.
|
|
* The type and the size of the local storage is defined
|
|
* by the *map* argument.
|
|
* The *flags* meaning is specific for each map type,
|
|
* and has to be 0 for cgroup local storage.
|
|
*
|
|
* Depending on the BPF program type, a local storage area
|
|
* can be shared between multiple instances of the BPF program,
|
|
* running simultaneously.
|
|
*
|
|
* A user should care about the synchronization by himself.
|
|
* For example, by using the **BPF_STX_XADD** instruction to alter
|
|
* the shared data.
|
|
* Return
|
|
* A pointer to the local storage area.
|
|
*
|
|
* int bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags)
|
|
* Description
|
|
* Select a **SO_REUSEPORT** socket from a
|
|
* **BPF_MAP_TYPE_REUSEPORT_ARRAY** *map*.
|
|
* It checks the selected socket is matching the incoming
|
|
* request in the socket buffer.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
|
|
* Description
|
|
* Look for TCP socket matching *tuple*, optionally in a child
|
|
* network namespace *netns*. The return value must be checked,
|
|
* and if non-**NULL**, released via **bpf_sk_release**\ ().
|
|
*
|
|
* The *ctx* should point to the context of the program, such as
|
|
* the skb or socket (depending on the hook in use). This is used
|
|
* to determine the base network namespace for the lookup.
|
|
*
|
|
* *tuple_size* must be one of:
|
|
*
|
|
* **sizeof**\ (*tuple*\ **->ipv4**)
|
|
* Look for an IPv4 socket.
|
|
* **sizeof**\ (*tuple*\ **->ipv6**)
|
|
* Look for an IPv6 socket.
|
|
*
|
|
* If the *netns* is a negative signed 32-bit integer, then the
|
|
* socket lookup table in the netns associated with the *ctx* will
|
|
* will be used. For the TC hooks, this is the netns of the device
|
|
* in the skb. For socket hooks, this is the netns of the socket.
|
|
* If *netns* is any other signed 32-bit value greater than or
|
|
* equal to zero then it specifies the ID of the netns relative to
|
|
* the netns associated with the *ctx*. *netns* values beyond the
|
|
* range of 32-bit integers are reserved for future use.
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* This helper is available only if the kernel was compiled with
|
|
* **CONFIG_NET** configuration option.
|
|
* Return
|
|
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
|
|
* For sockets with reuseport option, the **struct bpf_sock**
|
|
* result is from **reuse->socks**\ [] using the hash of the tuple.
|
|
*
|
|
* struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
|
|
* Description
|
|
* Look for UDP socket matching *tuple*, optionally in a child
|
|
* network namespace *netns*. The return value must be checked,
|
|
* and if non-**NULL**, released via **bpf_sk_release**\ ().
|
|
*
|
|
* The *ctx* should point to the context of the program, such as
|
|
* the skb or socket (depending on the hook in use). This is used
|
|
* to determine the base network namespace for the lookup.
|
|
*
|
|
* *tuple_size* must be one of:
|
|
*
|
|
* **sizeof**\ (*tuple*\ **->ipv4**)
|
|
* Look for an IPv4 socket.
|
|
* **sizeof**\ (*tuple*\ **->ipv6**)
|
|
* Look for an IPv6 socket.
|
|
*
|
|
* If the *netns* is a negative signed 32-bit integer, then the
|
|
* socket lookup table in the netns associated with the *ctx* will
|
|
* will be used. For the TC hooks, this is the netns of the device
|
|
* in the skb. For socket hooks, this is the netns of the socket.
|
|
* If *netns* is any other signed 32-bit value greater than or
|
|
* equal to zero then it specifies the ID of the netns relative to
|
|
* the netns associated with the *ctx*. *netns* values beyond the
|
|
* range of 32-bit integers are reserved for future use.
|
|
*
|
|
* All values for *flags* are reserved for future usage, and must
|
|
* be left at zero.
|
|
*
|
|
* This helper is available only if the kernel was compiled with
|
|
* **CONFIG_NET** configuration option.
|
|
* Return
|
|
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
|
|
* For sockets with reuseport option, the **struct bpf_sock**
|
|
* result is from **reuse->socks**\ [] using the hash of the tuple.
|
|
*
|
|
* int bpf_sk_release(struct bpf_sock *sock)
|
|
* Description
|
|
* Release the reference held by *sock*. *sock* must be a
|
|
* non-**NULL** pointer that was returned from
|
|
* **bpf_sk_lookup_xxx**\ ().
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_map_pop_elem(struct bpf_map *map, void *value)
|
|
* Description
|
|
* Pop an element from *map*.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_map_peek_elem(struct bpf_map *map, void *value)
|
|
* Description
|
|
* Get an element from *map* without removing it.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_msg_push_data(struct sk_buff *skb, u32 start, u32 len, u64 flags)
|
|
* Description
|
|
* For socket policies, insert *len* bytes into *msg* at offset
|
|
* *start*.
|
|
*
|
|
* If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
|
|
* *msg* it may want to insert metadata or options into the *msg*.
|
|
* This can later be read and used by any of the lower layer BPF
|
|
* hooks.
|
|
*
|
|
* This helper may fail if under memory pressure (a malloc
|
|
* fails) in these cases BPF programs will get an appropriate
|
|
* error and BPF programs will need to handle them.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 pop, u64 flags)
|
|
* Description
|
|
* Will remove *pop* bytes from a *msg* starting at byte *start*.
|
|
* This may result in **ENOMEM** errors under certain situations if
|
|
* an allocation and copy are required due to a full ring buffer.
|
|
* However, the helper will try to avoid doing the allocation
|
|
* if possible. Other errors can occur if input parameters are
|
|
* invalid either due to *start* byte not being valid part of *msg*
|
|
* payload and/or *pop* value being to large.
|
|
* Return
|
|
* 0 on success, or a negative error in case of failure.
|
|
*
|
|
* int bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
|
|
* Description
|
|
* This helper is used in programs implementing IR decoding, to
|
|
* report a successfully decoded pointer movement.
|
|
*
|
|
* The *ctx* should point to the lirc sample as passed into
|
|
* the program.
|
|
*
|
|
* This helper is only available is the kernel was compiled with
|
|
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
|
|
* "**y**".
|
|
* Return
|
|
* 0
|
|
*/
|
|
#define __BPF_FUNC_MAPPER(FN) \
|
|
FN(unspec), \
|
|
FN(map_lookup_elem), \
|
|
FN(map_update_elem), \
|
|
FN(map_delete_elem), \
|
|
FN(probe_read), \
|
|
FN(ktime_get_ns), \
|
|
FN(trace_printk), \
|
|
FN(get_prandom_u32), \
|
|
FN(get_smp_processor_id), \
|
|
FN(skb_store_bytes), \
|
|
FN(l3_csum_replace), \
|
|
FN(l4_csum_replace), \
|
|
FN(tail_call), \
|
|
FN(clone_redirect), \
|
|
FN(get_current_pid_tgid), \
|
|
FN(get_current_uid_gid), \
|
|
FN(get_current_comm), \
|
|
FN(get_cgroup_classid), \
|
|
FN(skb_vlan_push), \
|
|
FN(skb_vlan_pop), \
|
|
FN(skb_get_tunnel_key), \
|
|
FN(skb_set_tunnel_key), \
|
|
FN(perf_event_read), \
|
|
FN(redirect), \
|
|
FN(get_route_realm), \
|
|
FN(perf_event_output), \
|
|
FN(skb_load_bytes), \
|
|
FN(get_stackid), \
|
|
FN(csum_diff), \
|
|
FN(skb_get_tunnel_opt), \
|
|
FN(skb_set_tunnel_opt), \
|
|
FN(skb_change_proto), \
|
|
FN(skb_change_type), \
|
|
FN(skb_under_cgroup), \
|
|
FN(get_hash_recalc), \
|
|
FN(get_current_task), \
|
|
FN(probe_write_user), \
|
|
FN(current_task_under_cgroup), \
|
|
FN(skb_change_tail), \
|
|
FN(skb_pull_data), \
|
|
FN(csum_update), \
|
|
FN(set_hash_invalid), \
|
|
FN(get_numa_node_id), \
|
|
FN(skb_change_head), \
|
|
FN(xdp_adjust_head), \
|
|
FN(probe_read_str), \
|
|
FN(get_socket_cookie), \
|
|
FN(get_socket_uid), \
|
|
FN(set_hash), \
|
|
FN(setsockopt), \
|
|
FN(skb_adjust_room), \
|
|
FN(redirect_map), \
|
|
FN(sk_redirect_map), \
|
|
FN(sock_map_update), \
|
|
FN(xdp_adjust_meta), \
|
|
FN(perf_event_read_value), \
|
|
FN(perf_prog_read_value), \
|
|
FN(getsockopt), \
|
|
FN(override_return), \
|
|
FN(sock_ops_cb_flags_set), \
|
|
FN(msg_redirect_map), \
|
|
FN(msg_apply_bytes), \
|
|
FN(msg_cork_bytes), \
|
|
FN(msg_pull_data), \
|
|
FN(bind), \
|
|
FN(xdp_adjust_tail), \
|
|
FN(skb_get_xfrm_state), \
|
|
FN(get_stack), \
|
|
FN(skb_load_bytes_relative), \
|
|
FN(fib_lookup), \
|
|
FN(sock_hash_update), \
|
|
FN(msg_redirect_hash), \
|
|
FN(sk_redirect_hash), \
|
|
FN(lwt_push_encap), \
|
|
FN(lwt_seg6_store_bytes), \
|
|
FN(lwt_seg6_adjust_srh), \
|
|
FN(lwt_seg6_action), \
|
|
FN(rc_repeat), \
|
|
FN(rc_keydown), \
|
|
FN(skb_cgroup_id), \
|
|
FN(get_current_cgroup_id), \
|
|
FN(get_local_storage), \
|
|
FN(sk_select_reuseport), \
|
|
FN(skb_ancestor_cgroup_id), \
|
|
FN(sk_lookup_tcp), \
|
|
FN(sk_lookup_udp), \
|
|
FN(sk_release), \
|
|
FN(map_push_elem), \
|
|
FN(map_pop_elem), \
|
|
FN(map_peek_elem), \
|
|
FN(msg_push_data), \
|
|
FN(msg_pop_data), \
|
|
FN(rc_pointer_rel),
|
|
|
|
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
|
|
* function eBPF program intends to call
|
|
*/
|
|
#define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
|
|
enum bpf_func_id {
|
|
__BPF_FUNC_MAPPER(__BPF_ENUM_FN)
|
|
__BPF_FUNC_MAX_ID,
|
|
};
|
|
#undef __BPF_ENUM_FN
|
|
|
|
/* All flags used by eBPF helper functions, placed here. */
|
|
|
|
/* BPF_FUNC_skb_store_bytes flags. */
|
|
#define BPF_F_RECOMPUTE_CSUM (1ULL << 0)
|
|
#define BPF_F_INVALIDATE_HASH (1ULL << 1)
|
|
|
|
/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
|
|
* First 4 bits are for passing the header field size.
|
|
*/
|
|
#define BPF_F_HDR_FIELD_MASK 0xfULL
|
|
|
|
/* BPF_FUNC_l4_csum_replace flags. */
|
|
#define BPF_F_PSEUDO_HDR (1ULL << 4)
|
|
#define BPF_F_MARK_MANGLED_0 (1ULL << 5)
|
|
#define BPF_F_MARK_ENFORCE (1ULL << 6)
|
|
|
|
/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
|
|
#define BPF_F_INGRESS (1ULL << 0)
|
|
|
|
/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
|
|
#define BPF_F_TUNINFO_IPV6 (1ULL << 0)
|
|
|
|
/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
|
|
#define BPF_F_SKIP_FIELD_MASK 0xffULL
|
|
#define BPF_F_USER_STACK (1ULL << 8)
|
|
/* flags used by BPF_FUNC_get_stackid only. */
|
|
#define BPF_F_FAST_STACK_CMP (1ULL << 9)
|
|
#define BPF_F_REUSE_STACKID (1ULL << 10)
|
|
/* flags used by BPF_FUNC_get_stack only. */
|
|
#define BPF_F_USER_BUILD_ID (1ULL << 11)
|
|
|
|
/* BPF_FUNC_skb_set_tunnel_key flags. */
|
|
#define BPF_F_ZERO_CSUM_TX (1ULL << 1)
|
|
#define BPF_F_DONT_FRAGMENT (1ULL << 2)
|
|
#define BPF_F_SEQ_NUMBER (1ULL << 3)
|
|
|
|
/* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
|
|
* BPF_FUNC_perf_event_read_value flags.
|
|
*/
|
|
#define BPF_F_INDEX_MASK 0xffffffffULL
|
|
#define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK
|
|
/* BPF_FUNC_perf_event_output for sk_buff input context. */
|
|
#define BPF_F_CTXLEN_MASK (0xfffffULL << 32)
|
|
|
|
/* Current network namespace */
|
|
#define BPF_F_CURRENT_NETNS (-1L)
|
|
|
|
/* Mode for BPF_FUNC_skb_adjust_room helper. */
|
|
enum bpf_adj_room_mode {
|
|
BPF_ADJ_ROOM_NET,
|
|
};
|
|
|
|
/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
|
|
enum bpf_hdr_start_off {
|
|
BPF_HDR_START_MAC,
|
|
BPF_HDR_START_NET,
|
|
};
|
|
|
|
/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
|
|
enum bpf_lwt_encap_mode {
|
|
BPF_LWT_ENCAP_SEG6,
|
|
BPF_LWT_ENCAP_SEG6_INLINE
|
|
};
|
|
|
|
#define __bpf_md_ptr(type, name) \
|
|
union { \
|
|
type name; \
|
|
__u64 :64; \
|
|
} __attribute__((aligned(8)))
|
|
|
|
/* user accessible mirror of in-kernel sk_buff.
|
|
* new fields can only be added to the end of this structure
|
|
*/
|
|
struct __sk_buff {
|
|
__u32 len;
|
|
__u32 pkt_type;
|
|
__u32 mark;
|
|
__u32 queue_mapping;
|
|
__u32 protocol;
|
|
__u32 vlan_present;
|
|
__u32 vlan_tci;
|
|
__u32 vlan_proto;
|
|
__u32 priority;
|
|
__u32 ingress_ifindex;
|
|
__u32 ifindex;
|
|
__u32 tc_index;
|
|
__u32 cb[5];
|
|
__u32 hash;
|
|
__u32 tc_classid;
|
|
__u32 data;
|
|
__u32 data_end;
|
|
__u32 napi_id;
|
|
|
|
/* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */
|
|
__u32 family;
|
|
__u32 remote_ip4; /* Stored in network byte order */
|
|
__u32 local_ip4; /* Stored in network byte order */
|
|
__u32 remote_ip6[4]; /* Stored in network byte order */
|
|
__u32 local_ip6[4]; /* Stored in network byte order */
|
|
__u32 remote_port; /* Stored in network byte order */
|
|
__u32 local_port; /* stored in host byte order */
|
|
/* ... here. */
|
|
|
|
__u32 data_meta;
|
|
__bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
|
|
__u64 tstamp;
|
|
__u32 wire_len;
|
|
};
|
|
|
|
struct bpf_tunnel_key {
|
|
__u32 tunnel_id;
|
|
union {
|
|
__u32 remote_ipv4;
|
|
__u32 remote_ipv6[4];
|
|
};
|
|
__u8 tunnel_tos;
|
|
__u8 tunnel_ttl;
|
|
__u16 tunnel_ext; /* Padding, future use. */
|
|
__u32 tunnel_label;
|
|
};
|
|
|
|
/* user accessible mirror of in-kernel xfrm_state.
|
|
* new fields can only be added to the end of this structure
|
|
*/
|
|
struct bpf_xfrm_state {
|
|
__u32 reqid;
|
|
__u32 spi; /* Stored in network byte order */
|
|
__u16 family;
|
|
__u16 ext; /* Padding, future use. */
|
|
union {
|
|
__u32 remote_ipv4; /* Stored in network byte order */
|
|
__u32 remote_ipv6[4]; /* Stored in network byte order */
|
|
};
|
|
};
|
|
|
|
/* Generic BPF return codes which all BPF program types may support.
|
|
* The values are binary compatible with their TC_ACT_* counter-part to
|
|
* provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
|
|
* programs.
|
|
*
|
|
* XDP is handled seprately, see XDP_*.
|
|
*/
|
|
enum bpf_ret_code {
|
|
BPF_OK = 0,
|
|
/* 1 reserved */
|
|
BPF_DROP = 2,
|
|
/* 3-6 reserved */
|
|
BPF_REDIRECT = 7,
|
|
/* >127 are reserved for prog type specific return codes */
|
|
};
|
|
|
|
struct bpf_sock {
|
|
__u32 bound_dev_if;
|
|
__u32 family;
|
|
__u32 type;
|
|
__u32 protocol;
|
|
__u32 mark;
|
|
__u32 priority;
|
|
__u32 src_ip4; /* Allows 1,2,4-byte read.
|
|
* Stored in network byte order.
|
|
*/
|
|
__u32 src_ip6[4]; /* Allows 1,2,4-byte read.
|
|
* Stored in network byte order.
|
|
*/
|
|
__u32 src_port; /* Allows 4-byte read.
|
|
* Stored in host byte order
|
|
*/
|
|
};
|
|
|
|
struct bpf_sock_tuple {
|
|
union {
|
|
struct {
|
|
__be32 saddr;
|
|
__be32 daddr;
|
|
__be16 sport;
|
|
__be16 dport;
|
|
} ipv4;
|
|
struct {
|
|
__be32 saddr[4];
|
|
__be32 daddr[4];
|
|
__be16 sport;
|
|
__be16 dport;
|
|
} ipv6;
|
|
};
|
|
};
|
|
|
|
#define XDP_PACKET_HEADROOM 256
|
|
|
|
/* User return codes for XDP prog type.
|
|
* A valid XDP program must return one of these defined values. All other
|
|
* return codes are reserved for future use. Unknown return codes will
|
|
* result in packet drops and a warning via bpf_warn_invalid_xdp_action().
|
|
*/
|
|
enum xdp_action {
|
|
XDP_ABORTED = 0,
|
|
XDP_DROP,
|
|
XDP_PASS,
|
|
XDP_TX,
|
|
XDP_REDIRECT,
|
|
};
|
|
|
|
/* user accessible metadata for XDP packet hook
|
|
* new fields must be added to the end of this structure
|
|
*/
|
|
struct xdp_md {
|
|
__u32 data;
|
|
__u32 data_end;
|
|
__u32 data_meta;
|
|
/* Below access go through struct xdp_rxq_info */
|
|
__u32 ingress_ifindex; /* rxq->dev->ifindex */
|
|
__u32 rx_queue_index; /* rxq->queue_index */
|
|
};
|
|
|
|
enum sk_action {
|
|
SK_DROP = 0,
|
|
SK_PASS,
|
|
};
|
|
|
|
/* user accessible metadata for SK_MSG packet hook, new fields must
|
|
* be added to the end of this structure
|
|
*/
|
|
struct sk_msg_md {
|
|
__bpf_md_ptr(void *, data);
|
|
__bpf_md_ptr(void *, data_end);
|
|
|
|
__u32 family;
|
|
__u32 remote_ip4; /* Stored in network byte order */
|
|
__u32 local_ip4; /* Stored in network byte order */
|
|
__u32 remote_ip6[4]; /* Stored in network byte order */
|
|
__u32 local_ip6[4]; /* Stored in network byte order */
|
|
__u32 remote_port; /* Stored in network byte order */
|
|
__u32 local_port; /* stored in host byte order */
|
|
__u32 size; /* Total size of sk_msg */
|
|
};
|
|
|
|
struct sk_reuseport_md {
|
|
/*
|
|
* Start of directly accessible data. It begins from
|
|
* the tcp/udp header.
|
|
*/
|
|
__bpf_md_ptr(void *, data);
|
|
/* End of directly accessible data */
|
|
__bpf_md_ptr(void *, data_end);
|
|
/*
|
|
* Total length of packet (starting from the tcp/udp header).
|
|
* Note that the directly accessible bytes (data_end - data)
|
|
* could be less than this "len". Those bytes could be
|
|
* indirectly read by a helper "bpf_skb_load_bytes()".
|
|
*/
|
|
__u32 len;
|
|
/*
|
|
* Eth protocol in the mac header (network byte order). e.g.
|
|
* ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD)
|
|
*/
|
|
__u32 eth_protocol;
|
|
__u32 ip_protocol; /* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
|
|
__u32 bind_inany; /* Is sock bound to an INANY address? */
|
|
__u32 hash; /* A hash of the packet 4 tuples */
|
|
};
|
|
|
|
#define BPF_TAG_SIZE 8
|
|
|
|
struct bpf_prog_info {
|
|
__u32 type;
|
|
__u32 id;
|
|
__u8 tag[BPF_TAG_SIZE];
|
|
__u32 jited_prog_len;
|
|
__u32 xlated_prog_len;
|
|
__aligned_u64 jited_prog_insns;
|
|
__aligned_u64 xlated_prog_insns;
|
|
__u64 load_time; /* ns since boottime */
|
|
__u32 created_by_uid;
|
|
__u32 nr_map_ids;
|
|
__aligned_u64 map_ids;
|
|
char name[BPF_OBJ_NAME_LEN];
|
|
__u32 ifindex;
|
|
__u32 gpl_compatible:1;
|
|
__u64 netns_dev;
|
|
__u64 netns_ino;
|
|
__u32 nr_jited_ksyms;
|
|
__u32 nr_jited_func_lens;
|
|
__aligned_u64 jited_ksyms;
|
|
__aligned_u64 jited_func_lens;
|
|
__u32 btf_id;
|
|
__u32 func_info_rec_size;
|
|
__aligned_u64 func_info;
|
|
__u32 nr_func_info;
|
|
__u32 nr_line_info;
|
|
__aligned_u64 line_info;
|
|
__aligned_u64 jited_line_info;
|
|
__u32 nr_jited_line_info;
|
|
__u32 line_info_rec_size;
|
|
__u32 jited_line_info_rec_size;
|
|
__u32 nr_prog_tags;
|
|
__aligned_u64 prog_tags;
|
|
} __attribute__((aligned(8)));
|
|
|
|
struct bpf_map_info {
|
|
__u32 type;
|
|
__u32 id;
|
|
__u32 key_size;
|
|
__u32 value_size;
|
|
__u32 max_entries;
|
|
__u32 map_flags;
|
|
char name[BPF_OBJ_NAME_LEN];
|
|
__u32 ifindex;
|
|
__u32 :32;
|
|
__u64 netns_dev;
|
|
__u64 netns_ino;
|
|
__u32 btf_id;
|
|
__u32 btf_key_type_id;
|
|
__u32 btf_value_type_id;
|
|
} __attribute__((aligned(8)));
|
|
|
|
struct bpf_btf_info {
|
|
__aligned_u64 btf;
|
|
__u32 btf_size;
|
|
__u32 id;
|
|
} __attribute__((aligned(8)));
|
|
|
|
/* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
|
|
* by user and intended to be used by socket (e.g. to bind to, depends on
|
|
* attach attach type).
|
|
*/
|
|
struct bpf_sock_addr {
|
|
__u32 user_family; /* Allows 4-byte read, but no write. */
|
|
__u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write.
|
|
* Stored in network byte order.
|
|
*/
|
|
__u32 user_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
|
|
* Stored in network byte order.
|
|
*/
|
|
__u32 user_port; /* Allows 4-byte read and write.
|
|
* Stored in network byte order
|
|
*/
|
|
__u32 family; /* Allows 4-byte read, but no write */
|
|
__u32 type; /* Allows 4-byte read, but no write */
|
|
__u32 protocol; /* Allows 4-byte read, but no write */
|
|
__u32 msg_src_ip4; /* Allows 1,2,4-byte read an 4-byte write.
|
|
* Stored in network byte order.
|
|
*/
|
|
__u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
|
|
* Stored in network byte order.
|
|
*/
|
|
};
|
|
|
|
/* User bpf_sock_ops struct to access socket values and specify request ops
|
|
* and their replies.
|
|
* Some of this fields are in network (bigendian) byte order and may need
|
|
* to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
|
|
* New fields can only be added at the end of this structure
|
|
*/
|
|
struct bpf_sock_ops {
|
|
__u32 op;
|
|
union {
|
|
__u32 args[4]; /* Optionally passed to bpf program */
|
|
__u32 reply; /* Returned by bpf program */
|
|
__u32 replylong[4]; /* Optionally returned by bpf prog */
|
|
};
|
|
__u32 family;
|
|
__u32 remote_ip4; /* Stored in network byte order */
|
|
__u32 local_ip4; /* Stored in network byte order */
|
|
__u32 remote_ip6[4]; /* Stored in network byte order */
|
|
__u32 local_ip6[4]; /* Stored in network byte order */
|
|
__u32 remote_port; /* Stored in network byte order */
|
|
__u32 local_port; /* stored in host byte order */
|
|
__u32 is_fullsock; /* Some TCP fields are only valid if
|
|
* there is a full socket. If not, the
|
|
* fields read as zero.
|
|
*/
|
|
__u32 snd_cwnd;
|
|
__u32 srtt_us; /* Averaged RTT << 3 in usecs */
|
|
__u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
|
|
__u32 state;
|
|
__u32 rtt_min;
|
|
__u32 snd_ssthresh;
|
|
__u32 rcv_nxt;
|
|
__u32 snd_nxt;
|
|
__u32 snd_una;
|
|
__u32 mss_cache;
|
|
__u32 ecn_flags;
|
|
__u32 rate_delivered;
|
|
__u32 rate_interval_us;
|
|
__u32 packets_out;
|
|
__u32 retrans_out;
|
|
__u32 total_retrans;
|
|
__u32 segs_in;
|
|
__u32 data_segs_in;
|
|
__u32 segs_out;
|
|
__u32 data_segs_out;
|
|
__u32 lost_out;
|
|
__u32 sacked_out;
|
|
__u32 sk_txhash;
|
|
__u64 bytes_received;
|
|
__u64 bytes_acked;
|
|
};
|
|
|
|
/* Definitions for bpf_sock_ops_cb_flags */
|
|
#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0)
|
|
#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1)
|
|
#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2)
|
|
#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x7 /* Mask of all currently
|
|
* supported cb flags
|
|
*/
|
|
|
|
/* List of known BPF sock_ops operators.
|
|
* New entries can only be added at the end
|
|
*/
|
|
enum {
|
|
BPF_SOCK_OPS_VOID,
|
|
BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or
|
|
* -1 if default value should be used
|
|
*/
|
|
BPF_SOCK_OPS_RWND_INIT, /* Should return initial advertized
|
|
* window (in packets) or -1 if default
|
|
* value should be used
|
|
*/
|
|
BPF_SOCK_OPS_TCP_CONNECT_CB, /* Calls BPF program right before an
|
|
* active connection is initialized
|
|
*/
|
|
BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, /* Calls BPF program when an
|
|
* active connection is
|
|
* established
|
|
*/
|
|
BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, /* Calls BPF program when a
|
|
* passive connection is
|
|
* established
|
|
*/
|
|
BPF_SOCK_OPS_NEEDS_ECN, /* If connection's congestion control
|
|
* needs ECN
|
|
*/
|
|
BPF_SOCK_OPS_BASE_RTT, /* Get base RTT. The correct value is
|
|
* based on the path and may be
|
|
* dependent on the congestion control
|
|
* algorithm. In general it indicates
|
|
* a congestion threshold. RTTs above
|
|
* this indicate congestion
|
|
*/
|
|
BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered.
|
|
* Arg1: value of icsk_retransmits
|
|
* Arg2: value of icsk_rto
|
|
* Arg3: whether RTO has expired
|
|
*/
|
|
BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted.
|
|
* Arg1: sequence number of 1st byte
|
|
* Arg2: # segments
|
|
* Arg3: return value of
|
|
* tcp_transmit_skb (0 => success)
|
|
*/
|
|
BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state.
|
|
* Arg1: old_state
|
|
* Arg2: new_state
|
|
*/
|
|
BPF_SOCK_OPS_TCP_LISTEN_CB, /* Called on listen(2), right after
|
|
* socket transition to LISTEN state.
|
|
*/
|
|
};
|
|
|
|
/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
|
|
* changes between the TCP and BPF versions. Ideally this should never happen.
|
|
* If it does, we need to add code to convert them before calling
|
|
* the BPF sock_ops function.
|
|
*/
|
|
enum {
|
|
BPF_TCP_ESTABLISHED = 1,
|
|
BPF_TCP_SYN_SENT,
|
|
BPF_TCP_SYN_RECV,
|
|
BPF_TCP_FIN_WAIT1,
|
|
BPF_TCP_FIN_WAIT2,
|
|
BPF_TCP_TIME_WAIT,
|
|
BPF_TCP_CLOSE,
|
|
BPF_TCP_CLOSE_WAIT,
|
|
BPF_TCP_LAST_ACK,
|
|
BPF_TCP_LISTEN,
|
|
BPF_TCP_CLOSING, /* Now a valid state */
|
|
BPF_TCP_NEW_SYN_RECV,
|
|
|
|
BPF_TCP_MAX_STATES /* Leave at the end! */
|
|
};
|
|
|
|
#define TCP_BPF_IW 1001 /* Set TCP initial congestion window */
|
|
#define TCP_BPF_SNDCWND_CLAMP 1002 /* Set sndcwnd_clamp */
|
|
|
|
struct bpf_perf_event_value {
|
|
__u64 counter;
|
|
__u64 enabled;
|
|
__u64 running;
|
|
};
|
|
|
|
#define BPF_DEVCG_ACC_MKNOD (1ULL << 0)
|
|
#define BPF_DEVCG_ACC_READ (1ULL << 1)
|
|
#define BPF_DEVCG_ACC_WRITE (1ULL << 2)
|
|
|
|
#define BPF_DEVCG_DEV_BLOCK (1ULL << 0)
|
|
#define BPF_DEVCG_DEV_CHAR (1ULL << 1)
|
|
|
|
struct bpf_cgroup_dev_ctx {
|
|
/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
|
|
__u32 access_type;
|
|
__u32 major;
|
|
__u32 minor;
|
|
};
|
|
|
|
struct bpf_raw_tracepoint_args {
|
|
__u64 args[0];
|
|
};
|
|
|
|
/* DIRECT: Skip the FIB rules and go to FIB table associated with device
|
|
* OUTPUT: Do lookup from egress perspective; default is ingress
|
|
*/
|
|
#define BPF_FIB_LOOKUP_DIRECT BIT(0)
|
|
#define BPF_FIB_LOOKUP_OUTPUT BIT(1)
|
|
|
|
enum {
|
|
BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */
|
|
BPF_FIB_LKUP_RET_BLACKHOLE, /* dest is blackholed; can be dropped */
|
|
BPF_FIB_LKUP_RET_UNREACHABLE, /* dest is unreachable; can be dropped */
|
|
BPF_FIB_LKUP_RET_PROHIBIT, /* dest not allowed; can be dropped */
|
|
BPF_FIB_LKUP_RET_NOT_FWDED, /* packet is not forwarded */
|
|
BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */
|
|
BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */
|
|
BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */
|
|
BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */
|
|
};
|
|
|
|
struct bpf_fib_lookup {
|
|
/* input: network family for lookup (AF_INET, AF_INET6)
|
|
* output: network family of egress nexthop
|
|
*/
|
|
__u8 family;
|
|
|
|
/* set if lookup is to consider L4 data - e.g., FIB rules */
|
|
__u8 l4_protocol;
|
|
__be16 sport;
|
|
__be16 dport;
|
|
|
|
/* total length of packet from network header - used for MTU check */
|
|
__u16 tot_len;
|
|
|
|
/* input: L3 device index for lookup
|
|
* output: device index from FIB lookup
|
|
*/
|
|
__u32 ifindex;
|
|
|
|
union {
|
|
/* inputs to lookup */
|
|
__u8 tos; /* AF_INET */
|
|
__be32 flowinfo; /* AF_INET6, flow_label + priority */
|
|
|
|
/* output: metric of fib result (IPv4/IPv6 only) */
|
|
__u32 rt_metric;
|
|
};
|
|
|
|
union {
|
|
__be32 ipv4_src;
|
|
__u32 ipv6_src[4]; /* in6_addr; network order */
|
|
};
|
|
|
|
/* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in
|
|
* network header. output: bpf_fib_lookup sets to gateway address
|
|
* if FIB lookup returns gateway route
|
|
*/
|
|
union {
|
|
__be32 ipv4_dst;
|
|
__u32 ipv6_dst[4]; /* in6_addr; network order */
|
|
};
|
|
|
|
/* output */
|
|
__be16 h_vlan_proto;
|
|
__be16 h_vlan_TCI;
|
|
__u8 smac[6]; /* ETH_ALEN */
|
|
__u8 dmac[6]; /* ETH_ALEN */
|
|
};
|
|
|
|
enum bpf_task_fd_type {
|
|
BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */
|
|
BPF_FD_TYPE_TRACEPOINT, /* tp name */
|
|
BPF_FD_TYPE_KPROBE, /* (symbol + offset) or addr */
|
|
BPF_FD_TYPE_KRETPROBE, /* (symbol + offset) or addr */
|
|
BPF_FD_TYPE_UPROBE, /* filename + offset */
|
|
BPF_FD_TYPE_URETPROBE, /* filename + offset */
|
|
};
|
|
|
|
struct bpf_flow_keys {
|
|
__u16 nhoff;
|
|
__u16 thoff;
|
|
__u16 addr_proto; /* ETH_P_* of valid addrs */
|
|
__u8 is_frag;
|
|
__u8 is_first_frag;
|
|
__u8 is_encap;
|
|
__u8 ip_proto;
|
|
__be16 n_proto;
|
|
__be16 sport;
|
|
__be16 dport;
|
|
union {
|
|
struct {
|
|
__be32 ipv4_src;
|
|
__be32 ipv4_dst;
|
|
};
|
|
struct {
|
|
__u32 ipv6_src[4]; /* in6_addr; network order */
|
|
__u32 ipv6_dst[4]; /* in6_addr; network order */
|
|
};
|
|
};
|
|
};
|
|
|
|
struct bpf_func_info {
|
|
__u32 insn_off;
|
|
__u32 type_id;
|
|
};
|
|
|
|
#define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10)
|
|
#define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff)
|
|
|
|
struct bpf_line_info {
|
|
__u32 insn_off;
|
|
__u32 file_name_off;
|
|
__u32 line_off;
|
|
__u32 line_col;
|
|
};
|
|
|
|
#endif /* __LINUX_BPF_H__ */
|