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initial commit

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This initial commit added the following files
from bpf-next repository:
  src:
    <files from linux:tools/lib/bpf>
    bpf.c bpf.h btf.c btf.h libbpf.c libbpf.h
    libbpf_errno.c netlink.c nlattr.c nlattr.h
    str_error.c str_error.h
  include:
    <files from linux:tools/include/uapi/linux>
    uapi/linux/{bpf.h, btf.h}

    <files from linux:tools/include/tools>
    tools/libc_compat.h

The following files are also added:
  include/linux/{err.h, kernel.h, list.h, overflow.h, types.h}
These files are customized headers to satisfy compilation.
Their original counterparts are at linux:tools/include/linux
directory.

Signed-off-by: Yonghong Song <yhs@fb.com>
This commit is contained in:
Yonghong Song
2018-10-09 17:50:12 -07:00
commit 66684189f0
20 changed files with 7902 additions and 0 deletions
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11
include/linux/err.h Normal file
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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __LINUX_ERR_H
#define __LINUX_ERR_H
static inline void * ERR_PTR(long error_)
{
return (void *) error_;
}
#endif

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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __LINUX_KERNEL_H
#define __LINUX_KERNEL_H
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#define container_of(ptr, type, member) ({ \
const typeof(((type *)0)->member) * __mptr = (ptr); \
(type *)((char *)__mptr - offsetof(type, member)); })
#endif

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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __LINUX_LIST_H
#define __LINUX_LIST_H
#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) \
struct list_head name = LIST_HEAD_INIT(name)
#define list_entry(ptr, type, member) \
container_of(ptr, type, member)
#define list_first_entry(ptr, type, member) \
list_entry((ptr)->next, type, member)
#define list_next_entry(pos, member) \
list_entry((pos)->member.next, typeof(*(pos)), member)
#endif

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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __LINUX_OVERFLOW_H
#define __LINUX_OVERFLOW_H
#define is_signed_type(type) (((type)(-1)) < (type)1)
#define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type)))
#define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T)))
#define type_min(T) ((T)((T)-type_max(T)-(T)1))
#ifdef __GNUC__
#define GCC_VERSION (__GNUC__ * 10000 \
+ __GNUC_MINOR__ * 100 \
+ __GNUC_PATCHLEVEL__)
#if GCC_VERSION >= 50100
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif
#endif
#ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
#define check_mul_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
__builtin_mul_overflow(__a, __b, __d); \
})
#else
/* Checking for unsigned overflow is relatively easy without causing UB. */
#define __unsigned_add_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
*__d = __a + __b; \
*__d < __a; \
})
#define __unsigned_sub_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
*__d = __a - __b; \
__a < __b; \
})
/*
* If one of a or b is a compile-time constant, this avoids a division.
*/
#define __unsigned_mul_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
*__d = __a * __b; \
__builtin_constant_p(__b) ? \
__b > 0 && __a > type_max(typeof(__a)) / __b : \
__a > 0 && __b > type_max(typeof(__b)) / __a; \
})
/*
* For signed types, detecting overflow is much harder, especially if
* we want to avoid UB. But the interface of these macros is such that
* we must provide a result in *d, and in fact we must produce the
* result promised by gcc's builtins, which is simply the possibly
* wrapped-around value. Fortunately, we can just formally do the
* operations in the widest relevant unsigned type (u64) and then
* truncate the result - gcc is smart enough to generate the same code
* with and without the (u64) casts.
*/
/*
* Adding two signed integers can overflow only if they have the same
* sign, and overflow has happened iff the result has the opposite
* sign.
*/
#define __signed_add_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
*__d = (u64)__a + (u64)__b; \
(((~(__a ^ __b)) & (*__d ^ __a)) \
& type_min(typeof(__a))) != 0; \
})
/*
* Subtraction is similar, except that overflow can now happen only
* when the signs are opposite. In this case, overflow has happened if
* the result has the opposite sign of a.
*/
#define __signed_sub_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
*__d = (u64)__a - (u64)__b; \
((((__a ^ __b)) & (*__d ^ __a)) \
& type_min(typeof(__a))) != 0; \
})
/*
* Signed multiplication is rather hard. gcc always follows C99, so
* division is truncated towards 0. This means that we can write the
* overflow check like this:
*
* (a > 0 && (b > MAX/a || b < MIN/a)) ||
* (a < -1 && (b > MIN/a || b < MAX/a) ||
* (a == -1 && b == MIN)
*
* The redundant casts of -1 are to silence an annoying -Wtype-limits
* (included in -Wextra) warning: When the type is u8 or u16, the
* __b_c_e in check_mul_overflow obviously selects
* __unsigned_mul_overflow, but unfortunately gcc still parses this
* code and warns about the limited range of __b.
*/
#define __signed_mul_overflow(a, b, d) ({ \
typeof(a) __a = (a); \
typeof(b) __b = (b); \
typeof(d) __d = (d); \
typeof(a) __tmax = type_max(typeof(a)); \
typeof(a) __tmin = type_min(typeof(a)); \
(void) (&__a == &__b); \
(void) (&__a == __d); \
*__d = (u64)__a * (u64)__b; \
(__b > 0 && (__a > __tmax/__b || __a < __tmin/__b)) || \
(__b < (typeof(__b))-1 && (__a > __tmin/__b || __a < __tmax/__b)) || \
(__b == (typeof(__b))-1 && __a == __tmin); \
})
#define check_add_overflow(a, b, d) \
__builtin_choose_expr(is_signed_type(typeof(a)), \
__signed_add_overflow(a, b, d), \
__unsigned_add_overflow(a, b, d))
#define check_sub_overflow(a, b, d) \
__builtin_choose_expr(is_signed_type(typeof(a)), \
__signed_sub_overflow(a, b, d), \
__unsigned_sub_overflow(a, b, d))
#define check_mul_overflow(a, b, d) \
__builtin_choose_expr(is_signed_type(typeof(a)), \
__signed_mul_overflow(a, b, d), \
__unsigned_mul_overflow(a, b, d))
#endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */
/**
* array_size() - Calculate size of 2-dimensional array.
*
* @a: dimension one
* @b: dimension two
*
* Calculates size of 2-dimensional array: @a * @b.
*
* Returns: number of bytes needed to represent the array or SIZE_MAX on
* overflow.
*/
static inline size_t array_size(size_t a, size_t b)
{
size_t bytes;
if (check_mul_overflow(a, b, &bytes))
return SIZE_MAX;
return bytes;
}
/**
* array3_size() - Calculate size of 3-dimensional array.
*
* @a: dimension one
* @b: dimension two
* @c: dimension three
*
* Calculates size of 3-dimensional array: @a * @b * @c.
*
* Returns: number of bytes needed to represent the array or SIZE_MAX on
* overflow.
*/
static inline size_t array3_size(size_t a, size_t b, size_t c)
{
size_t bytes;
if (check_mul_overflow(a, b, &bytes))
return SIZE_MAX;
if (check_mul_overflow(bytes, c, &bytes))
return SIZE_MAX;
return bytes;
}
static inline size_t __ab_c_size(size_t n, size_t size, size_t c)
{
size_t bytes;
if (check_mul_overflow(n, size, &bytes))
return SIZE_MAX;
if (check_add_overflow(bytes, c, &bytes))
return SIZE_MAX;
return bytes;
}
#endif

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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __LINUX_TYPES_H
#define __LINUX_TYPES_H
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#define __SANE_USERSPACE_TYPES__ /* For PPC64, to get LL64 types */
#include <asm/types.h>
#include <asm/posix_types.h>
typedef uint64_t u64;
typedef int64_t s64;
typedef __u32 u32;
typedef __s32 s32;
typedef __u16 u16;
typedef __s16 s16;
typedef __u8 u8;
typedef __s8 s8;
#define __bitwise__
#define __bitwise __bitwise__
typedef __u16 __bitwise __le16;
typedef __u16 __bitwise __be16;
typedef __u32 __bitwise __le32;
typedef __u32 __bitwise __be32;
typedef __u64 __bitwise __le64;
typedef __u64 __bitwise __be64;
#ifndef __aligned_u64
# define __aligned_u64 __u64 __attribute__((aligned(8)))
#endif
struct list_head {
struct list_head *next, *prev;
};
#endif

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// SPDX-License-Identifier: (LGPL-2.0+ OR BSD-2-Clause)
/* Copyright (C) 2018 Netronome Systems, Inc. */
#ifndef __TOOLS_LIBC_COMPAT_H
#define __TOOLS_LIBC_COMPAT_H
#include <stdlib.h>
#include <linux/overflow.h>
#ifdef COMPAT_NEED_REALLOCARRAY
static inline void *reallocarray(void *ptr, size_t nmemb, size_t size)
{
size_t bytes;
if (unlikely(check_mul_overflow(nmemb, size, &bytes)))
return NULL;
return realloc(ptr, bytes);
}
#endif
#endif

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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/* Copyright (c) 2018 Facebook */
#ifndef _UAPI__LINUX_BTF_H__
#define _UAPI__LINUX_BTF_H__
#include <linux/types.h>
#define BTF_MAGIC 0xeB9F
#define BTF_VERSION 1
struct btf_header {
__u16 magic;
__u8 version;
__u8 flags;
__u32 hdr_len;
/* All offsets are in bytes relative to the end of this header */
__u32 type_off; /* offset of type section */
__u32 type_len; /* length of type section */
__u32 str_off; /* offset of string section */
__u32 str_len; /* length of string section */
};
/* Max # of type identifier */
#define BTF_MAX_TYPE 0x0000ffff
/* Max offset into the string section */
#define BTF_MAX_NAME_OFFSET 0x0000ffff
/* Max # of struct/union/enum members or func args */
#define BTF_MAX_VLEN 0xffff
struct btf_type {
__u32 name_off;
/* "info" bits arrangement
* bits 0-15: vlen (e.g. # of struct's members)
* bits 16-23: unused
* bits 24-27: kind (e.g. int, ptr, array...etc)
* bits 28-31: unused
*/
__u32 info;
/* "size" is used by INT, ENUM, STRUCT and UNION.
* "size" tells the size of the type it is describing.
*
* "type" is used by PTR, TYPEDEF, VOLATILE, CONST and RESTRICT.
* "type" is a type_id referring to another type.
*/
union {
__u32 size;
__u32 type;
};
};
#define BTF_INFO_KIND(info) (((info) >> 24) & 0x0f)
#define BTF_INFO_VLEN(info) ((info) & 0xffff)
#define BTF_KIND_UNKN 0 /* Unknown */
#define BTF_KIND_INT 1 /* Integer */
#define BTF_KIND_PTR 2 /* Pointer */
#define BTF_KIND_ARRAY 3 /* Array */
#define BTF_KIND_STRUCT 4 /* Struct */
#define BTF_KIND_UNION 5 /* Union */
#define BTF_KIND_ENUM 6 /* Enumeration */
#define BTF_KIND_FWD 7 /* Forward */
#define BTF_KIND_TYPEDEF 8 /* Typedef */
#define BTF_KIND_VOLATILE 9 /* Volatile */
#define BTF_KIND_CONST 10 /* Const */
#define BTF_KIND_RESTRICT 11 /* Restrict */
#define BTF_KIND_MAX 11
#define NR_BTF_KINDS 12
/* For some specific BTF_KIND, "struct btf_type" is immediately
* followed by extra data.
*/
/* BTF_KIND_INT is followed by a u32 and the following
* is the 32 bits arrangement:
*/
#define BTF_INT_ENCODING(VAL) (((VAL) & 0x0f000000) >> 24)
#define BTF_INT_OFFSET(VAL) (((VAL & 0x00ff0000)) >> 16)
#define BTF_INT_BITS(VAL) ((VAL) & 0x000000ff)
/* Attributes stored in the BTF_INT_ENCODING */
#define BTF_INT_SIGNED (1 << 0)
#define BTF_INT_CHAR (1 << 1)
#define BTF_INT_BOOL (1 << 2)
/* BTF_KIND_ENUM is followed by multiple "struct btf_enum".
* The exact number of btf_enum is stored in the vlen (of the
* info in "struct btf_type").
*/
struct btf_enum {
__u32 name_off;
__s32 val;
};
/* BTF_KIND_ARRAY is followed by one "struct btf_array" */
struct btf_array {
__u32 type;
__u32 index_type;
__u32 nelems;
};
/* BTF_KIND_STRUCT and BTF_KIND_UNION are followed
* by multiple "struct btf_member". The exact number
* of btf_member is stored in the vlen (of the info in
* "struct btf_type").
*/
struct btf_member {
__u32 name_off;
__u32 type;
__u32 offset; /* offset in bits */
};
#endif /* _UAPI__LINUX_BTF_H__ */

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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/*
* common eBPF ELF operations.
*
* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License (not later!)
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses>
*/
#include <stdlib.h>
#include <memory.h>
#include <unistd.h>
#include <asm/unistd.h>
#include <linux/bpf.h>
#include "bpf.h"
#include "libbpf.h"
#include <errno.h>
/*
* When building perf, unistd.h is overridden. __NR_bpf is
* required to be defined explicitly.
*/
#ifndef __NR_bpf
# if defined(__i386__)
# define __NR_bpf 357
# elif defined(__x86_64__)
# define __NR_bpf 321
# elif defined(__aarch64__)
# define __NR_bpf 280
# elif defined(__sparc__)
# define __NR_bpf 349
# elif defined(__s390__)
# define __NR_bpf 351
# else
# error __NR_bpf not defined. libbpf does not support your arch.
# endif
#endif
#ifndef min
#define min(x, y) ((x) < (y) ? (x) : (y))
#endif
static inline __u64 ptr_to_u64(const void *ptr)
{
return (__u64) (unsigned long) ptr;
}
static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
unsigned int size)
{
return syscall(__NR_bpf, cmd, attr, size);
}
int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
{
__u32 name_len = create_attr->name ? strlen(create_attr->name) : 0;
union bpf_attr attr;
memset(&attr, '\0', sizeof(attr));
attr.map_type = create_attr->map_type;
attr.key_size = create_attr->key_size;
attr.value_size = create_attr->value_size;
attr.max_entries = create_attr->max_entries;
attr.map_flags = create_attr->map_flags;
memcpy(attr.map_name, create_attr->name,
min(name_len, BPF_OBJ_NAME_LEN - 1));
attr.numa_node = create_attr->numa_node;
attr.btf_fd = create_attr->btf_fd;
attr.btf_key_type_id = create_attr->btf_key_type_id;
attr.btf_value_type_id = create_attr->btf_value_type_id;
attr.map_ifindex = create_attr->map_ifindex;
attr.inner_map_fd = create_attr->inner_map_fd;
return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}
int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
int key_size, int value_size, int max_entries,
__u32 map_flags, int node)
{
struct bpf_create_map_attr map_attr = {};
map_attr.name = name;
map_attr.map_type = map_type;
map_attr.map_flags = map_flags;
map_attr.key_size = key_size;
map_attr.value_size = value_size;
map_attr.max_entries = max_entries;
if (node >= 0) {
map_attr.numa_node = node;
map_attr.map_flags |= BPF_F_NUMA_NODE;
}
return bpf_create_map_xattr(&map_attr);
}
int bpf_create_map(enum bpf_map_type map_type, int key_size,
int value_size, int max_entries, __u32 map_flags)
{
struct bpf_create_map_attr map_attr = {};
map_attr.map_type = map_type;
map_attr.map_flags = map_flags;
map_attr.key_size = key_size;
map_attr.value_size = value_size;
map_attr.max_entries = max_entries;
return bpf_create_map_xattr(&map_attr);
}
int bpf_create_map_name(enum bpf_map_type map_type, const char *name,
int key_size, int value_size, int max_entries,
__u32 map_flags)
{
struct bpf_create_map_attr map_attr = {};
map_attr.name = name;
map_attr.map_type = map_type;
map_attr.map_flags = map_flags;
map_attr.key_size = key_size;
map_attr.value_size = value_size;
map_attr.max_entries = max_entries;
return bpf_create_map_xattr(&map_attr);
}
int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
int key_size, int inner_map_fd, int max_entries,
__u32 map_flags, int node)
{
__u32 name_len = name ? strlen(name) : 0;
union bpf_attr attr;
memset(&attr, '\0', sizeof(attr));
attr.map_type = map_type;
attr.key_size = key_size;
attr.value_size = 4;
attr.inner_map_fd = inner_map_fd;
attr.max_entries = max_entries;
attr.map_flags = map_flags;
memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
if (node >= 0) {
attr.map_flags |= BPF_F_NUMA_NODE;
attr.numa_node = node;
}
return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}
int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
int key_size, int inner_map_fd, int max_entries,
__u32 map_flags)
{
return bpf_create_map_in_map_node(map_type, name, key_size,
inner_map_fd, max_entries, map_flags,
-1);
}
int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
char *log_buf, size_t log_buf_sz)
{
union bpf_attr attr;
__u32 name_len;
int fd;
if (!load_attr)
return -EINVAL;
name_len = load_attr->name ? strlen(load_attr->name) : 0;
bzero(&attr, sizeof(attr));
attr.prog_type = load_attr->prog_type;
attr.expected_attach_type = load_attr->expected_attach_type;
attr.insn_cnt = (__u32)load_attr->insns_cnt;
attr.insns = ptr_to_u64(load_attr->insns);
attr.license = ptr_to_u64(load_attr->license);
attr.log_buf = ptr_to_u64(NULL);
attr.log_size = 0;
attr.log_level = 0;
attr.kern_version = load_attr->kern_version;
attr.prog_ifindex = load_attr->prog_ifindex;
memcpy(attr.prog_name, load_attr->name,
min(name_len, BPF_OBJ_NAME_LEN - 1));
fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
if (fd >= 0 || !log_buf || !log_buf_sz)
return fd;
/* Try again with log */
attr.log_buf = ptr_to_u64(log_buf);
attr.log_size = log_buf_sz;
attr.log_level = 1;
log_buf[0] = 0;
return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
}
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf,
size_t log_buf_sz)
{
struct bpf_load_program_attr load_attr;
memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
load_attr.prog_type = type;
load_attr.expected_attach_type = 0;
load_attr.name = NULL;
load_attr.insns = insns;
load_attr.insns_cnt = insns_cnt;
load_attr.license = license;
load_attr.kern_version = kern_version;
return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz);
}
int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, int strict_alignment,
const char *license, __u32 kern_version,
char *log_buf, size_t log_buf_sz, int log_level)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.prog_type = type;
attr.insn_cnt = (__u32)insns_cnt;
attr.insns = ptr_to_u64(insns);
attr.license = ptr_to_u64(license);
attr.log_buf = ptr_to_u64(log_buf);
attr.log_size = log_buf_sz;
attr.log_level = log_level;
log_buf[0] = 0;
attr.kern_version = kern_version;
attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
}
int bpf_map_update_elem(int fd, const void *key, const void *value,
__u64 flags)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.value = ptr_to_u64(value);
attr.flags = flags;
return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}
int bpf_map_lookup_elem(int fd, const void *key, void *value)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.value = ptr_to_u64(value);
return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}
int bpf_map_delete_elem(int fd, const void *key)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
}
int bpf_map_get_next_key(int fd, const void *key, void *next_key)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.map_fd = fd;
attr.key = ptr_to_u64(key);
attr.next_key = ptr_to_u64(next_key);
return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
}
int bpf_obj_pin(int fd, const char *pathname)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.pathname = ptr_to_u64((void *)pathname);
attr.bpf_fd = fd;
return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
}
int bpf_obj_get(const char *pathname)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.pathname = ptr_to_u64((void *)pathname);
return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
}
int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
unsigned int flags)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.target_fd = target_fd;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
attr.attach_flags = flags;
return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
}
int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.target_fd = target_fd;
attr.attach_type = type;
return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
}
int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.target_fd = target_fd;
attr.attach_bpf_fd = prog_fd;
attr.attach_type = type;
return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
}
int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
__u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
{
union bpf_attr attr;
int ret;
bzero(&attr, sizeof(attr));
attr.query.target_fd = target_fd;
attr.query.attach_type = type;
attr.query.query_flags = query_flags;
attr.query.prog_cnt = *prog_cnt;
attr.query.prog_ids = ptr_to_u64(prog_ids);
ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
if (attach_flags)
*attach_flags = attr.query.attach_flags;
*prog_cnt = attr.query.prog_cnt;
return ret;
}
int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
void *data_out, __u32 *size_out, __u32 *retval,
__u32 *duration)
{
union bpf_attr attr;
int ret;
bzero(&attr, sizeof(attr));
attr.test.prog_fd = prog_fd;
attr.test.data_in = ptr_to_u64(data);
attr.test.data_out = ptr_to_u64(data_out);
attr.test.data_size_in = size;
attr.test.repeat = repeat;
ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
if (size_out)
*size_out = attr.test.data_size_out;
if (retval)
*retval = attr.test.retval;
if (duration)
*duration = attr.test.duration;
return ret;
}
int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
{
union bpf_attr attr;
int err;
bzero(&attr, sizeof(attr));
attr.start_id = start_id;
err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
if (!err)
*next_id = attr.next_id;
return err;
}
int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
{
union bpf_attr attr;
int err;
bzero(&attr, sizeof(attr));
attr.start_id = start_id;
err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
if (!err)
*next_id = attr.next_id;
return err;
}
int bpf_prog_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.prog_id = id;
return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
}
int bpf_map_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.map_id = id;
return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
}
int bpf_btf_get_fd_by_id(__u32 id)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.btf_id = id;
return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr));
}
int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
{
union bpf_attr attr;
int err;
bzero(&attr, sizeof(attr));
attr.info.bpf_fd = prog_fd;
attr.info.info_len = *info_len;
attr.info.info = ptr_to_u64(info);
err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
if (!err)
*info_len = attr.info.info_len;
return err;
}
int bpf_raw_tracepoint_open(const char *name, int prog_fd)
{
union bpf_attr attr;
bzero(&attr, sizeof(attr));
attr.raw_tracepoint.name = ptr_to_u64(name);
attr.raw_tracepoint.prog_fd = prog_fd;
return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
}
int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
bool do_log)
{
union bpf_attr attr = {};
int fd;
attr.btf = ptr_to_u64(btf);
attr.btf_size = btf_size;
retry:
if (do_log && log_buf && log_buf_size) {
attr.btf_log_level = 1;
attr.btf_log_size = log_buf_size;
attr.btf_log_buf = ptr_to_u64(log_buf);
}
fd = sys_bpf(BPF_BTF_LOAD, &attr, sizeof(attr));
if (fd == -1 && !do_log && log_buf && log_buf_size) {
do_log = true;
goto retry;
}
return fd;
}
int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len,
__u32 *prog_id, __u32 *fd_type, __u64 *probe_offset,
__u64 *probe_addr)
{
union bpf_attr attr = {};
int err;
attr.task_fd_query.pid = pid;
attr.task_fd_query.fd = fd;
attr.task_fd_query.flags = flags;
attr.task_fd_query.buf = ptr_to_u64(buf);
attr.task_fd_query.buf_len = *buf_len;
err = sys_bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr));
*buf_len = attr.task_fd_query.buf_len;
*prog_id = attr.task_fd_query.prog_id;
*fd_type = attr.task_fd_query.fd_type;
*probe_offset = attr.task_fd_query.probe_offset;
*probe_addr = attr.task_fd_query.probe_addr;
return err;
}

114
src/bpf.h Normal file
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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/*
* common eBPF ELF operations.
*
* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License (not later!)
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses>
*/
#ifndef __LIBBPF_BPF_H
#define __LIBBPF_BPF_H
#include <linux/bpf.h>
#include <stdbool.h>
#include <stddef.h>
struct bpf_create_map_attr {
const char *name;
enum bpf_map_type map_type;
__u32 map_flags;
__u32 key_size;
__u32 value_size;
__u32 max_entries;
__u32 numa_node;
__u32 btf_fd;
__u32 btf_key_type_id;
__u32 btf_value_type_id;
__u32 map_ifindex;
__u32 inner_map_fd;
};
int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr);
int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
int key_size, int value_size, int max_entries,
__u32 map_flags, int node);
int bpf_create_map_name(enum bpf_map_type map_type, const char *name,
int key_size, int value_size, int max_entries,
__u32 map_flags);
int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries, __u32 map_flags);
int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
int key_size, int inner_map_fd, int max_entries,
__u32 map_flags, int node);
int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
int key_size, int inner_map_fd, int max_entries,
__u32 map_flags);
struct bpf_load_program_attr {
enum bpf_prog_type prog_type;
enum bpf_attach_type expected_attach_type;
const char *name;
const struct bpf_insn *insns;
size_t insns_cnt;
const char *license;
__u32 kern_version;
__u32 prog_ifindex;
};
/* Recommend log buffer size */
#define BPF_LOG_BUF_SIZE (256 * 1024)
int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
char *log_buf, size_t log_buf_sz);
int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, const char *license,
__u32 kern_version, char *log_buf,
size_t log_buf_sz);
int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
size_t insns_cnt, int strict_alignment,
const char *license, __u32 kern_version,
char *log_buf, size_t log_buf_sz, int log_level);
int bpf_map_update_elem(int fd, const void *key, const void *value,
__u64 flags);
int bpf_map_lookup_elem(int fd, const void *key, void *value);
int bpf_map_delete_elem(int fd, const void *key);
int bpf_map_get_next_key(int fd, const void *key, void *next_key);
int bpf_obj_pin(int fd, const char *pathname);
int bpf_obj_get(const char *pathname);
int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type,
unsigned int flags);
int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
int bpf_prog_detach2(int prog_fd, int attachable_fd, enum bpf_attach_type type);
int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
void *data_out, __u32 *size_out, __u32 *retval,
__u32 *duration);
int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id);
int bpf_map_get_next_id(__u32 start_id, __u32 *next_id);
int bpf_prog_get_fd_by_id(__u32 id);
int bpf_map_get_fd_by_id(__u32 id);
int bpf_btf_get_fd_by_id(__u32 id);
int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len);
int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
__u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt);
int bpf_raw_tracepoint_open(const char *name, int prog_fd);
int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
bool do_log);
int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len,
__u32 *prog_id, __u32 *fd_type, __u64 *probe_offset,
__u64 *probe_addr);
#endif /* __LIBBPF_BPF_H */

395
src/btf.c Normal file
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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2018 Facebook */
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <linux/err.h>
#include <linux/btf.h>
#include "btf.h"
#include "bpf.h"
#define elog(fmt, ...) { if (err_log) err_log(fmt, ##__VA_ARGS__); }
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) < (b) ? (a) : (b))
#define BTF_MAX_NR_TYPES 65535
#define IS_MODIFIER(k) (((k) == BTF_KIND_TYPEDEF) || \
((k) == BTF_KIND_VOLATILE) || \
((k) == BTF_KIND_CONST) || \
((k) == BTF_KIND_RESTRICT))
static struct btf_type btf_void;
struct btf {
union {
struct btf_header *hdr;
void *data;
};
struct btf_type **types;
const char *strings;
void *nohdr_data;
__u32 nr_types;
__u32 types_size;
__u32 data_size;
int fd;
};
static int btf_add_type(struct btf *btf, struct btf_type *t)
{
if (btf->types_size - btf->nr_types < 2) {
struct btf_type **new_types;
__u32 expand_by, new_size;
if (btf->types_size == BTF_MAX_NR_TYPES)
return -E2BIG;
expand_by = max(btf->types_size >> 2, 16);
new_size = min(BTF_MAX_NR_TYPES, btf->types_size + expand_by);
new_types = realloc(btf->types, sizeof(*new_types) * new_size);
if (!new_types)
return -ENOMEM;
if (btf->nr_types == 0)
new_types[0] = &btf_void;
btf->types = new_types;
btf->types_size = new_size;
}
btf->types[++(btf->nr_types)] = t;
return 0;
}
static int btf_parse_hdr(struct btf *btf, btf_print_fn_t err_log)
{
const struct btf_header *hdr = btf->hdr;
__u32 meta_left;
if (btf->data_size < sizeof(struct btf_header)) {
elog("BTF header not found\n");
return -EINVAL;
}
if (hdr->magic != BTF_MAGIC) {
elog("Invalid BTF magic:%x\n", hdr->magic);
return -EINVAL;
}
if (hdr->version != BTF_VERSION) {
elog("Unsupported BTF version:%u\n", hdr->version);
return -ENOTSUP;
}
if (hdr->flags) {
elog("Unsupported BTF flags:%x\n", hdr->flags);
return -ENOTSUP;
}
meta_left = btf->data_size - sizeof(*hdr);
if (!meta_left) {
elog("BTF has no data\n");
return -EINVAL;
}
if (meta_left < hdr->type_off) {
elog("Invalid BTF type section offset:%u\n", hdr->type_off);
return -EINVAL;
}
if (meta_left < hdr->str_off) {
elog("Invalid BTF string section offset:%u\n", hdr->str_off);
return -EINVAL;
}
if (hdr->type_off >= hdr->str_off) {
elog("BTF type section offset >= string section offset. No type?\n");
return -EINVAL;
}
if (hdr->type_off & 0x02) {
elog("BTF type section is not aligned to 4 bytes\n");
return -EINVAL;
}
btf->nohdr_data = btf->hdr + 1;
return 0;
}
static int btf_parse_str_sec(struct btf *btf, btf_print_fn_t err_log)
{
const struct btf_header *hdr = btf->hdr;
const char *start = btf->nohdr_data + hdr->str_off;
const char *end = start + btf->hdr->str_len;
if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET ||
start[0] || end[-1]) {
elog("Invalid BTF string section\n");
return -EINVAL;
}
btf->strings = start;
return 0;
}
static int btf_parse_type_sec(struct btf *btf, btf_print_fn_t err_log)
{
struct btf_header *hdr = btf->hdr;
void *nohdr_data = btf->nohdr_data;
void *next_type = nohdr_data + hdr->type_off;
void *end_type = nohdr_data + hdr->str_off;
while (next_type < end_type) {
struct btf_type *t = next_type;
__u16 vlen = BTF_INFO_VLEN(t->info);
int err;
next_type += sizeof(*t);
switch (BTF_INFO_KIND(t->info)) {
case BTF_KIND_INT:
next_type += sizeof(int);
break;
case BTF_KIND_ARRAY:
next_type += sizeof(struct btf_array);
break;
case BTF_KIND_STRUCT:
case BTF_KIND_UNION:
next_type += vlen * sizeof(struct btf_member);
break;
case BTF_KIND_ENUM:
next_type += vlen * sizeof(struct btf_enum);
break;
case BTF_KIND_TYPEDEF:
case BTF_KIND_PTR:
case BTF_KIND_FWD:
case BTF_KIND_VOLATILE:
case BTF_KIND_CONST:
case BTF_KIND_RESTRICT:
break;
default:
elog("Unsupported BTF_KIND:%u\n",
BTF_INFO_KIND(t->info));
return -EINVAL;
}
err = btf_add_type(btf, t);
if (err)
return err;
}
return 0;
}
const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
{
if (type_id > btf->nr_types)
return NULL;
return btf->types[type_id];
}
static bool btf_type_is_void(const struct btf_type *t)
{
return t == &btf_void || BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
}
static bool btf_type_is_void_or_null(const struct btf_type *t)
{
return !t || btf_type_is_void(t);
}
static __s64 btf_type_size(const struct btf_type *t)
{
switch (BTF_INFO_KIND(t->info)) {
case BTF_KIND_INT:
case BTF_KIND_STRUCT:
case BTF_KIND_UNION:
case BTF_KIND_ENUM:
return t->size;
case BTF_KIND_PTR:
return sizeof(void *);
default:
return -EINVAL;
}
}
#define MAX_RESOLVE_DEPTH 32
__s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
{
const struct btf_array *array;
const struct btf_type *t;
__u32 nelems = 1;
__s64 size = -1;
int i;
t = btf__type_by_id(btf, type_id);
for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t);
i++) {
size = btf_type_size(t);
if (size >= 0)
break;
switch (BTF_INFO_KIND(t->info)) {
case BTF_KIND_TYPEDEF:
case BTF_KIND_VOLATILE:
case BTF_KIND_CONST:
case BTF_KIND_RESTRICT:
type_id = t->type;
break;
case BTF_KIND_ARRAY:
array = (const struct btf_array *)(t + 1);
if (nelems && array->nelems > UINT32_MAX / nelems)
return -E2BIG;
nelems *= array->nelems;
type_id = array->type;
break;
default:
return -EINVAL;
}
t = btf__type_by_id(btf, type_id);
}
if (size < 0)
return -EINVAL;
if (nelems && size > UINT32_MAX / nelems)
return -E2BIG;
return nelems * size;
}
int btf__resolve_type(const struct btf *btf, __u32 type_id)
{
const struct btf_type *t;
int depth = 0;
t = btf__type_by_id(btf, type_id);
while (depth < MAX_RESOLVE_DEPTH &&
!btf_type_is_void_or_null(t) &&
IS_MODIFIER(BTF_INFO_KIND(t->info))) {
type_id = t->type;
t = btf__type_by_id(btf, type_id);
depth++;
}
if (depth == MAX_RESOLVE_DEPTH || btf_type_is_void_or_null(t))
return -EINVAL;
return type_id;
}
__s32 btf__find_by_name(const struct btf *btf, const char *type_name)
{
__u32 i;
if (!strcmp(type_name, "void"))
return 0;
for (i = 1; i <= btf->nr_types; i++) {
const struct btf_type *t = btf->types[i];
const char *name = btf__name_by_offset(btf, t->name_off);
if (name && !strcmp(type_name, name))
return i;
}
return -ENOENT;
}
void btf__free(struct btf *btf)
{
if (!btf)
return;
if (btf->fd != -1)
close(btf->fd);
free(btf->data);
free(btf->types);
free(btf);
}
struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log)
{
__u32 log_buf_size = 0;
char *log_buf = NULL;
struct btf *btf;
int err;
btf = calloc(1, sizeof(struct btf));
if (!btf)
return ERR_PTR(-ENOMEM);
btf->fd = -1;
if (err_log) {
log_buf = malloc(BPF_LOG_BUF_SIZE);
if (!log_buf) {
err = -ENOMEM;
goto done;
}
*log_buf = 0;
log_buf_size = BPF_LOG_BUF_SIZE;
}
btf->data = malloc(size);
if (!btf->data) {
err = -ENOMEM;
goto done;
}
memcpy(btf->data, data, size);
btf->data_size = size;
btf->fd = bpf_load_btf(btf->data, btf->data_size,
log_buf, log_buf_size, false);
if (btf->fd == -1) {
err = -errno;
elog("Error loading BTF: %s(%d)\n", strerror(errno), errno);
if (log_buf && *log_buf)
elog("%s\n", log_buf);
goto done;
}
err = btf_parse_hdr(btf, err_log);
if (err)
goto done;
err = btf_parse_str_sec(btf, err_log);
if (err)
goto done;
err = btf_parse_type_sec(btf, err_log);
done:
free(log_buf);
if (err) {
btf__free(btf);
return ERR_PTR(err);
}
return btf;
}
int btf__fd(const struct btf *btf)
{
return btf->fd;
}
const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
{
if (offset < btf->hdr->str_len)
return &btf->strings[offset];
else
return NULL;
}

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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2018 Facebook */
#ifndef __LIBBPF_BTF_H
#define __LIBBPF_BTF_H
#include <linux/types.h>
#define BTF_ELF_SEC ".BTF"
struct btf;
struct btf_type;
typedef int (*btf_print_fn_t)(const char *, ...)
__attribute__((format(printf, 1, 2)));
void btf__free(struct btf *btf);
struct btf *btf__new(__u8 *data, __u32 size, btf_print_fn_t err_log);
__s32 btf__find_by_name(const struct btf *btf, const char *type_name);
const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 id);
__s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
int btf__resolve_type(const struct btf *btf, __u32 type_id);
int btf__fd(const struct btf *btf);
const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
#endif /* __LIBBPF_BTF_H */

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src/libbpf.h Normal file
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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/*
* Common eBPF ELF object loading operations.
*
* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
*/
#ifndef __LIBBPF_LIBBPF_H
#define __LIBBPF_LIBBPF_H
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h> // for size_t
#include <linux/bpf.h>
enum libbpf_errno {
__LIBBPF_ERRNO__START = 4000,
/* Something wrong in libelf */
LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
LIBBPF_ERRNO__RELOC, /* Relocation failed */
LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
LIBBPF_ERRNO__PROG2BIG, /* Program too big */
LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */
LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */
LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */
__LIBBPF_ERRNO__END,
};
int libbpf_strerror(int err, char *buf, size_t size);
/*
* __printf is defined in include/linux/compiler-gcc.h. However,
* it would be better if libbpf.h didn't depend on Linux header files.
* So instead of __printf, here we use gcc attribute directly.
*/
typedef int (*libbpf_print_fn_t)(const char *, ...)
__attribute__((format(printf, 1, 2)));
void libbpf_set_print(libbpf_print_fn_t warn,
libbpf_print_fn_t info,
libbpf_print_fn_t debug);
/* Hide internal to user */
struct bpf_object;
struct bpf_object_open_attr {
const char *file;
enum bpf_prog_type prog_type;
};
struct bpf_object *bpf_object__open(const char *path);
struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr);
struct bpf_object *bpf_object__open_buffer(void *obj_buf,
size_t obj_buf_sz,
const char *name);
int bpf_object__pin(struct bpf_object *object, const char *path);
void bpf_object__close(struct bpf_object *object);
/* Load/unload object into/from kernel */
int bpf_object__load(struct bpf_object *obj);
int bpf_object__unload(struct bpf_object *obj);
const char *bpf_object__name(struct bpf_object *obj);
unsigned int bpf_object__kversion(struct bpf_object *obj);
int bpf_object__btf_fd(const struct bpf_object *obj);
struct bpf_program *
bpf_object__find_program_by_title(struct bpf_object *obj, const char *title);
struct bpf_object *bpf_object__next(struct bpf_object *prev);
#define bpf_object__for_each_safe(pos, tmp) \
for ((pos) = bpf_object__next(NULL), \
(tmp) = bpf_object__next(pos); \
(pos) != NULL; \
(pos) = (tmp), (tmp) = bpf_object__next(tmp))
typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
int bpf_object__set_priv(struct bpf_object *obj, void *priv,
bpf_object_clear_priv_t clear_priv);
void *bpf_object__priv(struct bpf_object *prog);
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
enum bpf_attach_type *expected_attach_type);
int libbpf_attach_type_by_name(const char *name,
enum bpf_attach_type *attach_type);
/* Accessors of bpf_program */
struct bpf_program;
struct bpf_program *bpf_program__next(struct bpf_program *prog,
struct bpf_object *obj);
#define bpf_object__for_each_program(pos, obj) \
for ((pos) = bpf_program__next(NULL, (obj)); \
(pos) != NULL; \
(pos) = bpf_program__next((pos), (obj)))
typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
void *);
int bpf_program__set_priv(struct bpf_program *prog, void *priv,
bpf_program_clear_priv_t clear_priv);
void *bpf_program__priv(struct bpf_program *prog);
void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex);
const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
int bpf_program__load(struct bpf_program *prog, char *license,
__u32 kern_version);
int bpf_program__fd(struct bpf_program *prog);
int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
int instance);
int bpf_program__pin(struct bpf_program *prog, const char *path);
void bpf_program__unload(struct bpf_program *prog);
struct bpf_insn;
/*
* Libbpf allows callers to adjust BPF programs before being loaded
* into kernel. One program in an object file can be transformed into
* multiple variants to be attached to different hooks.
*
* bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
* form an API for this purpose.
*
* - bpf_program_prep_t:
* Defines a 'preprocessor', which is a caller defined function
* passed to libbpf through bpf_program__set_prep(), and will be
* called before program is loaded. The processor should adjust
* the program one time for each instance according to the instance id
* passed to it.
*
* - bpf_program__set_prep:
* Attaches a preprocessor to a BPF program. The number of instances
* that should be created is also passed through this function.
*
* - bpf_program__nth_fd:
* After the program is loaded, get resulting FD of a given instance
* of the BPF program.
*
* If bpf_program__set_prep() is not used, the program would be loaded
* without adjustment during bpf_object__load(). The program has only
* one instance. In this case bpf_program__fd(prog) is equal to
* bpf_program__nth_fd(prog, 0).
*/
struct bpf_prog_prep_result {
/*
* If not NULL, load new instruction array.
* If set to NULL, don't load this instance.
*/
struct bpf_insn *new_insn_ptr;
int new_insn_cnt;
/* If not NULL, result FD is written to it. */
int *pfd;
};
/*
* Parameters of bpf_program_prep_t:
* - prog: The bpf_program being loaded.
* - n: Index of instance being generated.
* - insns: BPF instructions array.
* - insns_cnt:Number of instructions in insns.
* - res: Output parameter, result of transformation.
*
* Return value:
* - Zero: pre-processing success.
* - Non-zero: pre-processing error, stop loading.
*/
typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
struct bpf_insn *insns, int insns_cnt,
struct bpf_prog_prep_result *res);
int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
bpf_program_prep_t prep);
int bpf_program__nth_fd(struct bpf_program *prog, int n);
/*
* Adjust type of BPF program. Default is kprobe.
*/
int bpf_program__set_socket_filter(struct bpf_program *prog);
int bpf_program__set_tracepoint(struct bpf_program *prog);
int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
int bpf_program__set_kprobe(struct bpf_program *prog);
int bpf_program__set_sched_cls(struct bpf_program *prog);
int bpf_program__set_sched_act(struct bpf_program *prog);
int bpf_program__set_xdp(struct bpf_program *prog);
int bpf_program__set_perf_event(struct bpf_program *prog);
void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type);
void bpf_program__set_expected_attach_type(struct bpf_program *prog,
enum bpf_attach_type type);
bool bpf_program__is_socket_filter(struct bpf_program *prog);
bool bpf_program__is_tracepoint(struct bpf_program *prog);
bool bpf_program__is_raw_tracepoint(struct bpf_program *prog);
bool bpf_program__is_kprobe(struct bpf_program *prog);
bool bpf_program__is_sched_cls(struct bpf_program *prog);
bool bpf_program__is_sched_act(struct bpf_program *prog);
bool bpf_program__is_xdp(struct bpf_program *prog);
bool bpf_program__is_perf_event(struct bpf_program *prog);
/*
* No need for __attribute__((packed)), all members of 'bpf_map_def'
* are all aligned. In addition, using __attribute__((packed))
* would trigger a -Wpacked warning message, and lead to an error
* if -Werror is set.
*/
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
};
/*
* The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
* so no need to worry about a name clash.
*/
struct bpf_map;
struct bpf_map *
bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
/*
* Get bpf_map through the offset of corresponding struct bpf_map_def
* in the BPF object file.
*/
struct bpf_map *
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
struct bpf_map *
bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
#define bpf_map__for_each(pos, obj) \
for ((pos) = bpf_map__next(NULL, (obj)); \
(pos) != NULL; \
(pos) = bpf_map__next((pos), (obj)))
int bpf_map__fd(struct bpf_map *map);
const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
const char *bpf_map__name(struct bpf_map *map);
__u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
__u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
int bpf_map__set_priv(struct bpf_map *map, void *priv,
bpf_map_clear_priv_t clear_priv);
void *bpf_map__priv(struct bpf_map *map);
int bpf_map__reuse_fd(struct bpf_map *map, int fd);
bool bpf_map__is_offload_neutral(struct bpf_map *map);
void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
int bpf_map__pin(struct bpf_map *map, const char *path);
long libbpf_get_error(const void *ptr);
struct bpf_prog_load_attr {
const char *file;
enum bpf_prog_type prog_type;
enum bpf_attach_type expected_attach_type;
int ifindex;
};
int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
struct bpf_object **pobj, int *prog_fd);
int bpf_prog_load(const char *file, enum bpf_prog_type type,
struct bpf_object **pobj, int *prog_fd);
int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
enum bpf_perf_event_ret {
LIBBPF_PERF_EVENT_DONE = 0,
LIBBPF_PERF_EVENT_ERROR = -1,
LIBBPF_PERF_EVENT_CONT = -2,
};
typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event,
void *priv);
int bpf_perf_event_read_simple(void *mem, unsigned long size,
unsigned long page_size,
void **buf, size_t *buf_len,
bpf_perf_event_print_t fn, void *priv);
struct nlattr;
typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
int libbpf_netlink_open(unsigned int *nl_pid);
int libbpf_nl_get_link(int sock, unsigned int nl_pid,
libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
#endif /* __LIBBPF_LIBBPF_H */

62
src/libbpf_errno.c Normal file
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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/*
* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
* Copyright (C) 2017 Nicira, Inc.
*/
#include <stdio.h>
#include <string.h>
#include "libbpf.h"
#define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START)
#define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c)
#define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
static const char *libbpf_strerror_table[NR_ERRNO] = {
[ERRCODE_OFFSET(LIBELF)] = "Something wrong in libelf",
[ERRCODE_OFFSET(FORMAT)] = "BPF object format invalid",
[ERRCODE_OFFSET(KVERSION)] = "'version' section incorrect or lost",
[ERRCODE_OFFSET(ENDIAN)] = "Endian mismatch",
[ERRCODE_OFFSET(INTERNAL)] = "Internal error in libbpf",
[ERRCODE_OFFSET(RELOC)] = "Relocation failed",
[ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading",
[ERRCODE_OFFSET(PROG2BIG)] = "Program too big",
[ERRCODE_OFFSET(KVER)] = "Incorrect kernel version",
[ERRCODE_OFFSET(PROGTYPE)] = "Kernel doesn't support this program type",
[ERRCODE_OFFSET(WRNGPID)] = "Wrong pid in netlink message",
[ERRCODE_OFFSET(INVSEQ)] = "Invalid netlink sequence",
[ERRCODE_OFFSET(NLPARSE)] = "Incorrect netlink message parsing",
};
int libbpf_strerror(int err, char *buf, size_t size)
{
if (!buf || !size)
return -1;
err = err > 0 ? err : -err;
if (err < __LIBBPF_ERRNO__START) {
int ret;
ret = strerror_r(err, buf, size);
buf[size - 1] = '\0';
return ret;
}
if (err < __LIBBPF_ERRNO__END) {
const char *msg;
msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
snprintf(buf, size, "%s", msg);
buf[size - 1] = '\0';
return 0;
}
snprintf(buf, size, "Unknown libbpf error %d", err);
buf[size - 1] = '\0';
return -1;
}

337
src/netlink.c Normal file
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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2018 Facebook */
#include <stdlib.h>
#include <memory.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#include <errno.h>
#include <time.h>
#include "bpf.h"
#include "libbpf.h"
#include "nlattr.h"
#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif
typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
void *cookie);
int libbpf_netlink_open(__u32 *nl_pid)
{
struct sockaddr_nl sa;
socklen_t addrlen;
int one = 1, ret;
int sock;
memset(&sa, 0, sizeof(sa));
sa.nl_family = AF_NETLINK;
sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (sock < 0)
return -errno;
if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
&one, sizeof(one)) < 0) {
fprintf(stderr, "Netlink error reporting not supported\n");
}
if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
ret = -errno;
goto cleanup;
}
addrlen = sizeof(sa);
if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
ret = -errno;
goto cleanup;
}
if (addrlen != sizeof(sa)) {
ret = -LIBBPF_ERRNO__INTERNAL;
goto cleanup;
}
*nl_pid = sa.nl_pid;
return sock;
cleanup:
close(sock);
return ret;
}
static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq,
__dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
void *cookie)
{
bool multipart = true;
struct nlmsgerr *err;
struct nlmsghdr *nh;
char buf[4096];
int len, ret;
while (multipart) {
multipart = false;
len = recv(sock, buf, sizeof(buf), 0);
if (len < 0) {
ret = -errno;
goto done;
}
if (len == 0)
break;
for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
nh = NLMSG_NEXT(nh, len)) {
if (nh->nlmsg_pid != nl_pid) {
ret = -LIBBPF_ERRNO__WRNGPID;
goto done;
}
if (nh->nlmsg_seq != seq) {
ret = -LIBBPF_ERRNO__INVSEQ;
goto done;
}
if (nh->nlmsg_flags & NLM_F_MULTI)
multipart = true;
switch (nh->nlmsg_type) {
case NLMSG_ERROR:
err = (struct nlmsgerr *)NLMSG_DATA(nh);
if (!err->error)
continue;
ret = err->error;
libbpf_nla_dump_errormsg(nh);
goto done;
case NLMSG_DONE:
return 0;
default:
break;
}
if (_fn) {
ret = _fn(nh, fn, cookie);
if (ret)
return ret;
}
}
}
ret = 0;
done:
return ret;
}
int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
{
int sock, seq = 0, ret;
struct nlattr *nla, *nla_xdp;
struct {
struct nlmsghdr nh;
struct ifinfomsg ifinfo;
char attrbuf[64];
} req;
__u32 nl_pid;
sock = libbpf_netlink_open(&nl_pid);
if (sock < 0)
return sock;
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
req.nh.nlmsg_type = RTM_SETLINK;
req.nh.nlmsg_pid = 0;
req.nh.nlmsg_seq = ++seq;
req.ifinfo.ifi_family = AF_UNSPEC;
req.ifinfo.ifi_index = ifindex;
/* started nested attribute for XDP */
nla = (struct nlattr *)(((char *)&req)
+ NLMSG_ALIGN(req.nh.nlmsg_len));
nla->nla_type = NLA_F_NESTED | IFLA_XDP;
nla->nla_len = NLA_HDRLEN;
/* add XDP fd */
nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
nla_xdp->nla_type = IFLA_XDP_FD;
nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
nla->nla_len += nla_xdp->nla_len;
/* if user passed in any flags, add those too */
if (flags) {
nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
nla_xdp->nla_type = IFLA_XDP_FLAGS;
nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
nla->nla_len += nla_xdp->nla_len;
}
req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
ret = -errno;
goto cleanup;
}
ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL);
cleanup:
close(sock);
return ret;
}
static int __dump_link_nlmsg(struct nlmsghdr *nlh,
libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
{
struct nlattr *tb[IFLA_MAX + 1], *attr;
struct ifinfomsg *ifi = NLMSG_DATA(nlh);
int len;
len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_link_nlmsg(cookie, ifi, tb);
}
int libbpf_nl_get_link(int sock, unsigned int nl_pid,
libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
{
struct {
struct nlmsghdr nlh;
struct ifinfomsg ifm;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
.nlh.nlmsg_type = RTM_GETLINK,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.ifm.ifi_family = AF_PACKET,
};
int seq = time(NULL);
req.nlh.nlmsg_seq = seq;
if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
return -errno;
return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
dump_link_nlmsg, cookie);
}
static int __dump_class_nlmsg(struct nlmsghdr *nlh,
libbpf_dump_nlmsg_t dump_class_nlmsg,
void *cookie)
{
struct nlattr *tb[TCA_MAX + 1], *attr;
struct tcmsg *t = NLMSG_DATA(nlh);
int len;
len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_class_nlmsg(cookie, t, tb);
}
int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie)
{
struct {
struct nlmsghdr nlh;
struct tcmsg t;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
.nlh.nlmsg_type = RTM_GETTCLASS,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.t.tcm_family = AF_UNSPEC,
.t.tcm_ifindex = ifindex,
};
int seq = time(NULL);
req.nlh.nlmsg_seq = seq;
if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
return -errno;
return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
dump_class_nlmsg, cookie);
}
static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
libbpf_dump_nlmsg_t dump_qdisc_nlmsg,
void *cookie)
{
struct nlattr *tb[TCA_MAX + 1], *attr;
struct tcmsg *t = NLMSG_DATA(nlh);
int len;
len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_qdisc_nlmsg(cookie, t, tb);
}
int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
{
struct {
struct nlmsghdr nlh;
struct tcmsg t;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
.nlh.nlmsg_type = RTM_GETQDISC,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.t.tcm_family = AF_UNSPEC,
.t.tcm_ifindex = ifindex,
};
int seq = time(NULL);
req.nlh.nlmsg_seq = seq;
if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
return -errno;
return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
dump_qdisc_nlmsg, cookie);
}
static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
libbpf_dump_nlmsg_t dump_filter_nlmsg,
void *cookie)
{
struct nlattr *tb[TCA_MAX + 1], *attr;
struct tcmsg *t = NLMSG_DATA(nlh);
int len;
len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_filter_nlmsg(cookie, t, tb);
}
int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie)
{
struct {
struct nlmsghdr nlh;
struct tcmsg t;
} req = {
.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
.nlh.nlmsg_type = RTM_GETTFILTER,
.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.t.tcm_family = AF_UNSPEC,
.t.tcm_ifindex = ifindex,
.t.tcm_parent = handle,
};
int seq = time(NULL);
req.nlh.nlmsg_seq = seq;
if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
return -errno;
return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
dump_filter_nlmsg, cookie);
}

195
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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/*
* NETLINK Netlink attributes
*
* Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
*/
#include <errno.h>
#include "nlattr.h"
#include <linux/rtnetlink.h>
#include <string.h>
#include <stdio.h>
static uint16_t nla_attr_minlen[LIBBPF_NLA_TYPE_MAX+1] = {
[LIBBPF_NLA_U8] = sizeof(uint8_t),
[LIBBPF_NLA_U16] = sizeof(uint16_t),
[LIBBPF_NLA_U32] = sizeof(uint32_t),
[LIBBPF_NLA_U64] = sizeof(uint64_t),
[LIBBPF_NLA_STRING] = 1,
[LIBBPF_NLA_FLAG] = 0,
};
static struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
{
int totlen = NLA_ALIGN(nla->nla_len);
*remaining -= totlen;
return (struct nlattr *) ((char *) nla + totlen);
}
static int nla_ok(const struct nlattr *nla, int remaining)
{
return remaining >= sizeof(*nla) &&
nla->nla_len >= sizeof(*nla) &&
nla->nla_len <= remaining;
}
static int nla_type(const struct nlattr *nla)
{
return nla->nla_type & NLA_TYPE_MASK;
}
static int validate_nla(struct nlattr *nla, int maxtype,
struct libbpf_nla_policy *policy)
{
struct libbpf_nla_policy *pt;
unsigned int minlen = 0;
int type = nla_type(nla);
if (type < 0 || type > maxtype)
return 0;
pt = &policy[type];
if (pt->type > LIBBPF_NLA_TYPE_MAX)
return 0;
if (pt->minlen)
minlen = pt->minlen;
else if (pt->type != LIBBPF_NLA_UNSPEC)
minlen = nla_attr_minlen[pt->type];
if (libbpf_nla_len(nla) < minlen)
return -1;
if (pt->maxlen && libbpf_nla_len(nla) > pt->maxlen)
return -1;
if (pt->type == LIBBPF_NLA_STRING) {
char *data = libbpf_nla_data(nla);
if (data[libbpf_nla_len(nla) - 1] != '\0')
return -1;
}
return 0;
}
static inline int nlmsg_len(const struct nlmsghdr *nlh)
{
return nlh->nlmsg_len - NLMSG_HDRLEN;
}
/**
* Create attribute index based on a stream of attributes.
* @arg tb Index array to be filled (maxtype+1 elements).
* @arg maxtype Maximum attribute type expected and accepted.
* @arg head Head of attribute stream.
* @arg len Length of attribute stream.
* @arg policy Attribute validation policy.
*
* Iterates over the stream of attributes and stores a pointer to each
* attribute in the index array using the attribute type as index to
* the array. Attribute with a type greater than the maximum type
* specified will be silently ignored in order to maintain backwards
* compatibility. If \a policy is not NULL, the attribute will be
* validated using the specified policy.
*
* @see nla_validate
* @return 0 on success or a negative error code.
*/
int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
int len, struct libbpf_nla_policy *policy)
{
struct nlattr *nla;
int rem, err;
memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
libbpf_nla_for_each_attr(nla, head, len, rem) {
int type = nla_type(nla);
if (type > maxtype)
continue;
if (policy) {
err = validate_nla(nla, maxtype, policy);
if (err < 0)
goto errout;
}
if (tb[type])
fprintf(stderr, "Attribute of type %#x found multiple times in message, "
"previous attribute is being ignored.\n", type);
tb[type] = nla;
}
err = 0;
errout:
return err;
}
/**
* Create attribute index based on nested attribute
* @arg tb Index array to be filled (maxtype+1 elements).
* @arg maxtype Maximum attribute type expected and accepted.
* @arg nla Nested Attribute.
* @arg policy Attribute validation policy.
*
* Feeds the stream of attributes nested into the specified attribute
* to libbpf_nla_parse().
*
* @see libbpf_nla_parse
* @return 0 on success or a negative error code.
*/
int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
struct nlattr *nla,
struct libbpf_nla_policy *policy)
{
return libbpf_nla_parse(tb, maxtype, libbpf_nla_data(nla),
libbpf_nla_len(nla), policy);
}
/* dump netlink extended ack error message */
int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh)
{
struct libbpf_nla_policy extack_policy[NLMSGERR_ATTR_MAX + 1] = {
[NLMSGERR_ATTR_MSG] = { .type = LIBBPF_NLA_STRING },
[NLMSGERR_ATTR_OFFS] = { .type = LIBBPF_NLA_U32 },
};
struct nlattr *tb[NLMSGERR_ATTR_MAX + 1], *attr;
struct nlmsgerr *err;
char *errmsg = NULL;
int hlen, alen;
/* no TLVs, nothing to do here */
if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
return 0;
err = (struct nlmsgerr *)NLMSG_DATA(nlh);
hlen = sizeof(*err);
/* if NLM_F_CAPPED is set then the inner err msg was capped */
if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
hlen += nlmsg_len(&err->msg);
attr = (struct nlattr *) ((void *) err + hlen);
alen = nlh->nlmsg_len - hlen;
if (libbpf_nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen,
extack_policy) != 0) {
fprintf(stderr,
"Failed to parse extended error attributes\n");
return 0;
}
if (tb[NLMSGERR_ATTR_MSG])
errmsg = (char *) libbpf_nla_data(tb[NLMSGERR_ATTR_MSG]);
fprintf(stderr, "Kernel error message: %s\n", errmsg);
return 0;
}

106
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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/*
* NETLINK Netlink attributes
*
* Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
*/
#ifndef __LIBBPF_NLATTR_H
#define __LIBBPF_NLATTR_H
#include <stdint.h>
#include <linux/netlink.h>
/* avoid multiple definition of netlink features */
#define __LINUX_NETLINK_H
/**
* Standard attribute types to specify validation policy
*/
enum {
LIBBPF_NLA_UNSPEC, /**< Unspecified type, binary data chunk */
LIBBPF_NLA_U8, /**< 8 bit integer */
LIBBPF_NLA_U16, /**< 16 bit integer */
LIBBPF_NLA_U32, /**< 32 bit integer */
LIBBPF_NLA_U64, /**< 64 bit integer */
LIBBPF_NLA_STRING, /**< NUL terminated character string */
LIBBPF_NLA_FLAG, /**< Flag */
LIBBPF_NLA_MSECS, /**< Micro seconds (64bit) */
LIBBPF_NLA_NESTED, /**< Nested attributes */
__LIBBPF_NLA_TYPE_MAX,
};
#define LIBBPF_NLA_TYPE_MAX (__LIBBPF_NLA_TYPE_MAX - 1)
/**
* @ingroup attr
* Attribute validation policy.
*
* See section @core_doc{core_attr_parse,Attribute Parsing} for more details.
*/
struct libbpf_nla_policy {
/** Type of attribute or LIBBPF_NLA_UNSPEC */
uint16_t type;
/** Minimal length of payload required */
uint16_t minlen;
/** Maximal length of payload allowed */
uint16_t maxlen;
};
/**
* @ingroup attr
* Iterate over a stream of attributes
* @arg pos loop counter, set to current attribute
* @arg head head of attribute stream
* @arg len length of attribute stream
* @arg rem initialized to len, holds bytes currently remaining in stream
*/
#define libbpf_nla_for_each_attr(pos, head, len, rem) \
for (pos = head, rem = len; \
nla_ok(pos, rem); \
pos = nla_next(pos, &(rem)))
/**
* libbpf_nla_data - head of payload
* @nla: netlink attribute
*/
static inline void *libbpf_nla_data(const struct nlattr *nla)
{
return (char *) nla + NLA_HDRLEN;
}
static inline uint8_t libbpf_nla_getattr_u8(const struct nlattr *nla)
{
return *(uint8_t *)libbpf_nla_data(nla);
}
static inline uint32_t libbpf_nla_getattr_u32(const struct nlattr *nla)
{
return *(uint32_t *)libbpf_nla_data(nla);
}
static inline const char *libbpf_nla_getattr_str(const struct nlattr *nla)
{
return (const char *)libbpf_nla_data(nla);
}
/**
* libbpf_nla_len - length of payload
* @nla: netlink attribute
*/
static inline int libbpf_nla_len(const struct nlattr *nla)
{
return nla->nla_len - NLA_HDRLEN;
}
int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
int len, struct libbpf_nla_policy *policy);
int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
struct nlattr *nla,
struct libbpf_nla_policy *policy);
int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh);
#endif /* __LIBBPF_NLATTR_H */

18
src/str_error.c Normal file
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// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
#undef _GNU_SOURCE
#include <string.h>
#include <stdio.h>
#include "str_error.h"
/*
* Wrapper to allow for building in non-GNU systems such as Alpine Linux's musl
* libc, while checking strerror_r() return to avoid having to check this in
* all places calling it.
*/
char *libbpf_strerror_r(int err, char *dst, int len)
{
int ret = strerror_r(err, dst, len);
if (ret)
snprintf(dst, len, "ERROR: strerror_r(%d)=%d", err, ret);
return dst;
}

6
src/str_error.h Normal file
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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __LIBBPF_STR_ERROR_H
#define __LIBBPF_STR_ERROR_H
char *libbpf_strerror_r(int err, char *dst, int len);
#endif /* __LIBBPF_STR_ERROR_H */