tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * common eBPF ELF operations.
3 *
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation;
11 * version 2.1 of the License (not later!)
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this program; if not, see <http://www.gnu.org/licenses>
20 */
21
22#include <stdlib.h>
23#include <memory.h>
24#include <unistd.h>
25#include <asm/unistd.h>
26#include <linux/bpf.h>
27#include "bpf.h"
28
29/*
30 * When building perf, unistd.h is overridden. __NR_bpf is
31 * required to be defined explicitly.
32 */
33#ifndef __NR_bpf
34# if defined(__i386__)
35# define __NR_bpf 357
36# elif defined(__x86_64__)
37# define __NR_bpf 321
38# elif defined(__aarch64__)
39# define __NR_bpf 280
40# elif defined(__sparc__)
41# define __NR_bpf 349
42# else
43# error __NR_bpf not defined. libbpf does not support your arch.
44# endif
45#endif
46
47static inline __u64 ptr_to_u64(const void *ptr)
48{
49 return (__u64) (unsigned long) ptr;
50}
51
52static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
53 unsigned int size)
54{
55 return syscall(__NR_bpf, cmd, attr, size);
56}
57
58int bpf_create_map(enum bpf_map_type map_type, int key_size,
59 int value_size, int max_entries, __u32 map_flags)
60{
61 union bpf_attr attr;
62
63 memset(&attr, '\0', sizeof(attr));
64
65 attr.map_type = map_type;
66 attr.key_size = key_size;
67 attr.value_size = value_size;
68 attr.max_entries = max_entries;
69 attr.map_flags = map_flags;
70
71 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
72}
73
74int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size,
75 int inner_map_fd, int max_entries, __u32 map_flags)
76{
77 union bpf_attr attr;
78
79 memset(&attr, '\0', sizeof(attr));
80
81 attr.map_type = map_type;
82 attr.key_size = key_size;
83 attr.value_size = 4;
84 attr.inner_map_fd = inner_map_fd;
85 attr.max_entries = max_entries;
86 attr.map_flags = map_flags;
87
88 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
89}
90
91int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
92 size_t insns_cnt, const char *license,
93 __u32 kern_version, char *log_buf, size_t log_buf_sz)
94{
95 int fd;
96 union bpf_attr attr;
97
98 bzero(&attr, sizeof(attr));
99 attr.prog_type = type;
100 attr.insn_cnt = (__u32)insns_cnt;
101 attr.insns = ptr_to_u64(insns);
102 attr.license = ptr_to_u64(license);
103 attr.log_buf = ptr_to_u64(NULL);
104 attr.log_size = 0;
105 attr.log_level = 0;
106 attr.kern_version = kern_version;
107
108 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
109 if (fd >= 0 || !log_buf || !log_buf_sz)
110 return fd;
111
112 /* Try again with log */
113 attr.log_buf = ptr_to_u64(log_buf);
114 attr.log_size = log_buf_sz;
115 attr.log_level = 1;
116 log_buf[0] = 0;
117 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
118}
119
120int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
121 size_t insns_cnt, int strict_alignment,
122 const char *license, __u32 kern_version,
123 char *log_buf, size_t log_buf_sz, int log_level)
124{
125 union bpf_attr attr;
126
127 bzero(&attr, sizeof(attr));
128 attr.prog_type = type;
129 attr.insn_cnt = (__u32)insns_cnt;
130 attr.insns = ptr_to_u64(insns);
131 attr.license = ptr_to_u64(license);
132 attr.log_buf = ptr_to_u64(log_buf);
133 attr.log_size = log_buf_sz;
134 attr.log_level = log_level;
135 log_buf[0] = 0;
136 attr.kern_version = kern_version;
137 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
138
139 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
140}
141
142int bpf_map_update_elem(int fd, const void *key, const void *value,
143 __u64 flags)
144{
145 union bpf_attr attr;
146
147 bzero(&attr, sizeof(attr));
148 attr.map_fd = fd;
149 attr.key = ptr_to_u64(key);
150 attr.value = ptr_to_u64(value);
151 attr.flags = flags;
152
153 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
154}
155
156int bpf_map_lookup_elem(int fd, const void *key, void *value)
157{
158 union bpf_attr attr;
159
160 bzero(&attr, sizeof(attr));
161 attr.map_fd = fd;
162 attr.key = ptr_to_u64(key);
163 attr.value = ptr_to_u64(value);
164
165 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
166}
167
168int bpf_map_delete_elem(int fd, const void *key)
169{
170 union bpf_attr attr;
171
172 bzero(&attr, sizeof(attr));
173 attr.map_fd = fd;
174 attr.key = ptr_to_u64(key);
175
176 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
177}
178
179int bpf_map_get_next_key(int fd, const void *key, void *next_key)
180{
181 union bpf_attr attr;
182
183 bzero(&attr, sizeof(attr));
184 attr.map_fd = fd;
185 attr.key = ptr_to_u64(key);
186 attr.next_key = ptr_to_u64(next_key);
187
188 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
189}
190
191int bpf_obj_pin(int fd, const char *pathname)
192{
193 union bpf_attr attr;
194
195 bzero(&attr, sizeof(attr));
196 attr.pathname = ptr_to_u64((void *)pathname);
197 attr.bpf_fd = fd;
198
199 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
200}
201
202int bpf_obj_get(const char *pathname)
203{
204 union bpf_attr attr;
205
206 bzero(&attr, sizeof(attr));
207 attr.pathname = ptr_to_u64((void *)pathname);
208
209 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
210}
211
212int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
213 unsigned int flags)
214{
215 union bpf_attr attr;
216
217 bzero(&attr, sizeof(attr));
218 attr.target_fd = target_fd;
219 attr.attach_bpf_fd = prog_fd;
220 attr.attach_type = type;
221 attr.attach_flags = flags;
222
223 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
224}
225
226int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
227{
228 union bpf_attr attr;
229
230 bzero(&attr, sizeof(attr));
231 attr.target_fd = target_fd;
232 attr.attach_type = type;
233
234 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
235}
236
237int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
238 void *data_out, __u32 *size_out, __u32 *retval,
239 __u32 *duration)
240{
241 union bpf_attr attr;
242 int ret;
243
244 bzero(&attr, sizeof(attr));
245 attr.test.prog_fd = prog_fd;
246 attr.test.data_in = ptr_to_u64(data);
247 attr.test.data_out = ptr_to_u64(data_out);
248 attr.test.data_size_in = size;
249 attr.test.repeat = repeat;
250
251 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
252 if (size_out)
253 *size_out = attr.test.data_size_out;
254 if (retval)
255 *retval = attr.test.retval;
256 if (duration)
257 *duration = attr.test.duration;
258 return ret;
259}
260
261int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
262{
263 union bpf_attr attr;
264 int err;
265
266 bzero(&attr, sizeof(attr));
267 attr.start_id = start_id;
268
269 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
270 if (!err)
271 *next_id = attr.next_id;
272
273 return err;
274}
275
276int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
277{
278 union bpf_attr attr;
279 int err;
280
281 bzero(&attr, sizeof(attr));
282 attr.start_id = start_id;
283
284 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
285 if (!err)
286 *next_id = attr.next_id;
287
288 return err;
289}
290
291int bpf_prog_get_fd_by_id(__u32 id)
292{
293 union bpf_attr attr;
294
295 bzero(&attr, sizeof(attr));
296 attr.prog_id = id;
297
298 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
299}
300
301int bpf_map_get_fd_by_id(__u32 id)
302{
303 union bpf_attr attr;
304
305 bzero(&attr, sizeof(attr));
306 attr.map_id = id;
307
308 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
309}
310
311int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
312{
313 union bpf_attr attr;
314 int err;
315
316 bzero(&attr, sizeof(attr));
317 bzero(info, *info_len);
318 attr.info.bpf_fd = prog_fd;
319 attr.info.info_len = *info_len;
320 attr.info.info = ptr_to_u64(info);
321
322 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
323 if (!err)
324 *info_len = attr.info.info_len;
325
326 return err;
327}