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1// SPDX-License-Identifier: LGPL-2.1
2
3/*
4 * common eBPF ELF operations.
5 *
6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
8 * Copyright (C) 2015 Huawei Inc.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation;
13 * version 2.1 of the License (not later!)
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with this program; if not, see <http://www.gnu.org/licenses>
22 */
23
24#include <stdlib.h>
25#include <memory.h>
26#include <unistd.h>
27#include <asm/unistd.h>
28#include <linux/bpf.h>
29#include "bpf.h"
30#include "libbpf.h"
31#include "nlattr.h"
32#include <linux/rtnetlink.h>
33#include <linux/if_link.h>
34#include <sys/socket.h>
35#include <errno.h>
36
37#ifndef SOL_NETLINK
38#define SOL_NETLINK 270
39#endif
40
41/*
42 * When building perf, unistd.h is overridden. __NR_bpf is
43 * required to be defined explicitly.
44 */
45#ifndef __NR_bpf
46# if defined(__i386__)
47# define __NR_bpf 357
48# elif defined(__x86_64__)
49# define __NR_bpf 321
50# elif defined(__aarch64__)
51# define __NR_bpf 280
52# elif defined(__sparc__)
53# define __NR_bpf 349
54# elif defined(__s390__)
55# define __NR_bpf 351
56# else
57# error __NR_bpf not defined. libbpf does not support your arch.
58# endif
59#endif
60
61#ifndef min
62#define min(x, y) ((x) < (y) ? (x) : (y))
63#endif
64
65static inline __u64 ptr_to_u64(const void *ptr)
66{
67 return (__u64) (unsigned long) ptr;
68}
69
70static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
71 unsigned int size)
72{
73 return syscall(__NR_bpf, cmd, attr, size);
74}
75
76int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
77 int key_size, int value_size, int max_entries,
78 __u32 map_flags, int node)
79{
80 __u32 name_len = name ? strlen(name) : 0;
81 union bpf_attr attr;
82
83 memset(&attr, '\0', sizeof(attr));
84
85 attr.map_type = map_type;
86 attr.key_size = key_size;
87 attr.value_size = value_size;
88 attr.max_entries = max_entries;
89 attr.map_flags = map_flags;
90 memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
91
92 if (node >= 0) {
93 attr.map_flags |= BPF_F_NUMA_NODE;
94 attr.numa_node = node;
95 }
96
97 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
98}
99
100int bpf_create_map(enum bpf_map_type map_type, int key_size,
101 int value_size, int max_entries, __u32 map_flags)
102{
103 return bpf_create_map_node(map_type, NULL, key_size, value_size,
104 max_entries, map_flags, -1);
105}
106
107int bpf_create_map_name(enum bpf_map_type map_type, const char *name,
108 int key_size, int value_size, int max_entries,
109 __u32 map_flags)
110{
111 return bpf_create_map_node(map_type, name, key_size, value_size,
112 max_entries, map_flags, -1);
113}
114
115int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
116 int key_size, int inner_map_fd, int max_entries,
117 __u32 map_flags, int node)
118{
119 __u32 name_len = name ? strlen(name) : 0;
120 union bpf_attr attr;
121
122 memset(&attr, '\0', sizeof(attr));
123
124 attr.map_type = map_type;
125 attr.key_size = key_size;
126 attr.value_size = 4;
127 attr.inner_map_fd = inner_map_fd;
128 attr.max_entries = max_entries;
129 attr.map_flags = map_flags;
130 memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
131
132 if (node >= 0) {
133 attr.map_flags |= BPF_F_NUMA_NODE;
134 attr.numa_node = node;
135 }
136
137 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
138}
139
140int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name,
141 int key_size, int inner_map_fd, int max_entries,
142 __u32 map_flags)
143{
144 return bpf_create_map_in_map_node(map_type, name, key_size,
145 inner_map_fd, max_entries, map_flags,
146 -1);
147}
148
149int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
150 char *log_buf, size_t log_buf_sz)
151{
152 union bpf_attr attr;
153 __u32 name_len;
154 int fd;
155
156 if (!load_attr)
157 return -EINVAL;
158
159 name_len = load_attr->name ? strlen(load_attr->name) : 0;
160
161 bzero(&attr, sizeof(attr));
162 attr.prog_type = load_attr->prog_type;
163 attr.expected_attach_type = load_attr->expected_attach_type;
164 attr.insn_cnt = (__u32)load_attr->insns_cnt;
165 attr.insns = ptr_to_u64(load_attr->insns);
166 attr.license = ptr_to_u64(load_attr->license);
167 attr.log_buf = ptr_to_u64(NULL);
168 attr.log_size = 0;
169 attr.log_level = 0;
170 attr.kern_version = load_attr->kern_version;
171 memcpy(attr.prog_name, load_attr->name,
172 min(name_len, BPF_OBJ_NAME_LEN - 1));
173
174 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
175 if (fd >= 0 || !log_buf || !log_buf_sz)
176 return fd;
177
178 /* Try again with log */
179 attr.log_buf = ptr_to_u64(log_buf);
180 attr.log_size = log_buf_sz;
181 attr.log_level = 1;
182 log_buf[0] = 0;
183 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
184}
185
186int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
187 size_t insns_cnt, const char *license,
188 __u32 kern_version, char *log_buf,
189 size_t log_buf_sz)
190{
191 struct bpf_load_program_attr load_attr;
192
193 memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
194 load_attr.prog_type = type;
195 load_attr.expected_attach_type = 0;
196 load_attr.name = NULL;
197 load_attr.insns = insns;
198 load_attr.insns_cnt = insns_cnt;
199 load_attr.license = license;
200 load_attr.kern_version = kern_version;
201
202 return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz);
203}
204
205int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns,
206 size_t insns_cnt, int strict_alignment,
207 const char *license, __u32 kern_version,
208 char *log_buf, size_t log_buf_sz, int log_level)
209{
210 union bpf_attr attr;
211
212 bzero(&attr, sizeof(attr));
213 attr.prog_type = type;
214 attr.insn_cnt = (__u32)insns_cnt;
215 attr.insns = ptr_to_u64(insns);
216 attr.license = ptr_to_u64(license);
217 attr.log_buf = ptr_to_u64(log_buf);
218 attr.log_size = log_buf_sz;
219 attr.log_level = log_level;
220 log_buf[0] = 0;
221 attr.kern_version = kern_version;
222 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0;
223
224 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
225}
226
227int bpf_map_update_elem(int fd, const void *key, const void *value,
228 __u64 flags)
229{
230 union bpf_attr attr;
231
232 bzero(&attr, sizeof(attr));
233 attr.map_fd = fd;
234 attr.key = ptr_to_u64(key);
235 attr.value = ptr_to_u64(value);
236 attr.flags = flags;
237
238 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
239}
240
241int bpf_map_lookup_elem(int fd, const void *key, void *value)
242{
243 union bpf_attr attr;
244
245 bzero(&attr, sizeof(attr));
246 attr.map_fd = fd;
247 attr.key = ptr_to_u64(key);
248 attr.value = ptr_to_u64(value);
249
250 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
251}
252
253int bpf_map_delete_elem(int fd, const void *key)
254{
255 union bpf_attr attr;
256
257 bzero(&attr, sizeof(attr));
258 attr.map_fd = fd;
259 attr.key = ptr_to_u64(key);
260
261 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
262}
263
264int bpf_map_get_next_key(int fd, const void *key, void *next_key)
265{
266 union bpf_attr attr;
267
268 bzero(&attr, sizeof(attr));
269 attr.map_fd = fd;
270 attr.key = ptr_to_u64(key);
271 attr.next_key = ptr_to_u64(next_key);
272
273 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
274}
275
276int bpf_obj_pin(int fd, const char *pathname)
277{
278 union bpf_attr attr;
279
280 bzero(&attr, sizeof(attr));
281 attr.pathname = ptr_to_u64((void *)pathname);
282 attr.bpf_fd = fd;
283
284 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
285}
286
287int bpf_obj_get(const char *pathname)
288{
289 union bpf_attr attr;
290
291 bzero(&attr, sizeof(attr));
292 attr.pathname = ptr_to_u64((void *)pathname);
293
294 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
295}
296
297int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type,
298 unsigned int flags)
299{
300 union bpf_attr attr;
301
302 bzero(&attr, sizeof(attr));
303 attr.target_fd = target_fd;
304 attr.attach_bpf_fd = prog_fd;
305 attr.attach_type = type;
306 attr.attach_flags = flags;
307
308 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
309}
310
311int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
312{
313 union bpf_attr attr;
314
315 bzero(&attr, sizeof(attr));
316 attr.target_fd = target_fd;
317 attr.attach_type = type;
318
319 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
320}
321
322int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
323{
324 union bpf_attr attr;
325
326 bzero(&attr, sizeof(attr));
327 attr.target_fd = target_fd;
328 attr.attach_bpf_fd = prog_fd;
329 attr.attach_type = type;
330
331 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
332}
333
334int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
335 __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
336{
337 union bpf_attr attr;
338 int ret;
339
340 bzero(&attr, sizeof(attr));
341 attr.query.target_fd = target_fd;
342 attr.query.attach_type = type;
343 attr.query.query_flags = query_flags;
344 attr.query.prog_cnt = *prog_cnt;
345 attr.query.prog_ids = ptr_to_u64(prog_ids);
346
347 ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
348 if (attach_flags)
349 *attach_flags = attr.query.attach_flags;
350 *prog_cnt = attr.query.prog_cnt;
351 return ret;
352}
353
354int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
355 void *data_out, __u32 *size_out, __u32 *retval,
356 __u32 *duration)
357{
358 union bpf_attr attr;
359 int ret;
360
361 bzero(&attr, sizeof(attr));
362 attr.test.prog_fd = prog_fd;
363 attr.test.data_in = ptr_to_u64(data);
364 attr.test.data_out = ptr_to_u64(data_out);
365 attr.test.data_size_in = size;
366 attr.test.repeat = repeat;
367
368 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
369 if (size_out)
370 *size_out = attr.test.data_size_out;
371 if (retval)
372 *retval = attr.test.retval;
373 if (duration)
374 *duration = attr.test.duration;
375 return ret;
376}
377
378int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id)
379{
380 union bpf_attr attr;
381 int err;
382
383 bzero(&attr, sizeof(attr));
384 attr.start_id = start_id;
385
386 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr));
387 if (!err)
388 *next_id = attr.next_id;
389
390 return err;
391}
392
393int bpf_map_get_next_id(__u32 start_id, __u32 *next_id)
394{
395 union bpf_attr attr;
396 int err;
397
398 bzero(&attr, sizeof(attr));
399 attr.start_id = start_id;
400
401 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr));
402 if (!err)
403 *next_id = attr.next_id;
404
405 return err;
406}
407
408int bpf_prog_get_fd_by_id(__u32 id)
409{
410 union bpf_attr attr;
411
412 bzero(&attr, sizeof(attr));
413 attr.prog_id = id;
414
415 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
416}
417
418int bpf_map_get_fd_by_id(__u32 id)
419{
420 union bpf_attr attr;
421
422 bzero(&attr, sizeof(attr));
423 attr.map_id = id;
424
425 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
426}
427
428int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len)
429{
430 union bpf_attr attr;
431 int err;
432
433 bzero(&attr, sizeof(attr));
434 attr.info.bpf_fd = prog_fd;
435 attr.info.info_len = *info_len;
436 attr.info.info = ptr_to_u64(info);
437
438 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
439 if (!err)
440 *info_len = attr.info.info_len;
441
442 return err;
443}
444
445int bpf_raw_tracepoint_open(const char *name, int prog_fd)
446{
447 union bpf_attr attr;
448
449 bzero(&attr, sizeof(attr));
450 attr.raw_tracepoint.name = ptr_to_u64(name);
451 attr.raw_tracepoint.prog_fd = prog_fd;
452
453 return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
454}
455
456int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
457{
458 struct sockaddr_nl sa;
459 int sock, seq = 0, len, ret = -1;
460 char buf[4096];
461 struct nlattr *nla, *nla_xdp;
462 struct {
463 struct nlmsghdr nh;
464 struct ifinfomsg ifinfo;
465 char attrbuf[64];
466 } req;
467 struct nlmsghdr *nh;
468 struct nlmsgerr *err;
469 socklen_t addrlen;
470 int one = 1;
471
472 memset(&sa, 0, sizeof(sa));
473 sa.nl_family = AF_NETLINK;
474
475 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
476 if (sock < 0) {
477 return -errno;
478 }
479
480 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
481 &one, sizeof(one)) < 0) {
482 fprintf(stderr, "Netlink error reporting not supported\n");
483 }
484
485 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
486 ret = -errno;
487 goto cleanup;
488 }
489
490 addrlen = sizeof(sa);
491 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
492 ret = -errno;
493 goto cleanup;
494 }
495
496 if (addrlen != sizeof(sa)) {
497 ret = -LIBBPF_ERRNO__INTERNAL;
498 goto cleanup;
499 }
500
501 memset(&req, 0, sizeof(req));
502 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
503 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
504 req.nh.nlmsg_type = RTM_SETLINK;
505 req.nh.nlmsg_pid = 0;
506 req.nh.nlmsg_seq = ++seq;
507 req.ifinfo.ifi_family = AF_UNSPEC;
508 req.ifinfo.ifi_index = ifindex;
509
510 /* started nested attribute for XDP */
511 nla = (struct nlattr *)(((char *)&req)
512 + NLMSG_ALIGN(req.nh.nlmsg_len));
513 nla->nla_type = NLA_F_NESTED | IFLA_XDP;
514 nla->nla_len = NLA_HDRLEN;
515
516 /* add XDP fd */
517 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
518 nla_xdp->nla_type = IFLA_XDP_FD;
519 nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
520 memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
521 nla->nla_len += nla_xdp->nla_len;
522
523 /* if user passed in any flags, add those too */
524 if (flags) {
525 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
526 nla_xdp->nla_type = IFLA_XDP_FLAGS;
527 nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
528 memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
529 nla->nla_len += nla_xdp->nla_len;
530 }
531
532 req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
533
534 if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
535 ret = -errno;
536 goto cleanup;
537 }
538
539 len = recv(sock, buf, sizeof(buf), 0);
540 if (len < 0) {
541 ret = -errno;
542 goto cleanup;
543 }
544
545 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
546 nh = NLMSG_NEXT(nh, len)) {
547 if (nh->nlmsg_pid != sa.nl_pid) {
548 ret = -LIBBPF_ERRNO__WRNGPID;
549 goto cleanup;
550 }
551 if (nh->nlmsg_seq != seq) {
552 ret = -LIBBPF_ERRNO__INVSEQ;
553 goto cleanup;
554 }
555 switch (nh->nlmsg_type) {
556 case NLMSG_ERROR:
557 err = (struct nlmsgerr *)NLMSG_DATA(nh);
558 if (!err->error)
559 continue;
560 ret = err->error;
561 nla_dump_errormsg(nh);
562 goto cleanup;
563 case NLMSG_DONE:
564 break;
565 default:
566 break;
567 }
568 }
569
570 ret = 0;
571
572cleanup:
573 close(sock);
574 return ret;
575}