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Commit | Line | Data |
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1d129d19 JP |
1 | /* |
2 | * tc_bpf.c BPF common code | |
3 | * | |
4 | * This program is free software; you can distribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Authors: Daniel Borkmann <dborkman@redhat.com> | |
10 | * Jiri Pirko <jiri@resnulli.us> | |
11c39b5e | 11 | * Alexei Starovoitov <ast@plumgrid.com> |
1d129d19 JP |
12 | */ |
13 | ||
14 | #include <stdio.h> | |
15 | #include <stdlib.h> | |
16 | #include <unistd.h> | |
17 | #include <string.h> | |
18 | #include <stdbool.h> | |
473d7840 | 19 | #include <stdint.h> |
1d129d19 | 20 | #include <errno.h> |
11c39b5e DB |
21 | #include <fcntl.h> |
22 | #include <stdarg.h> | |
1d129d19 | 23 | |
11c39b5e DB |
24 | #ifdef HAVE_ELF |
25 | #include <libelf.h> | |
26 | #include <gelf.h> | |
27 | #endif | |
28 | ||
32e93fb7 DB |
29 | #include <sys/types.h> |
30 | #include <sys/stat.h> | |
31 | #include <sys/un.h> | |
32 | #include <sys/vfs.h> | |
33 | #include <sys/mount.h> | |
34 | #include <sys/syscall.h> | |
35 | #include <sys/sendfile.h> | |
36 | #include <sys/resource.h> | |
37 | ||
38 | #include <linux/bpf.h> | |
39 | #include <linux/filter.h> | |
40 | #include <linux/if_alg.h> | |
41 | ||
8187b012 DB |
42 | #include <arpa/inet.h> |
43 | ||
1d129d19 | 44 | #include "utils.h" |
6256f8c9 DB |
45 | |
46 | #include "bpf_elf.h" | |
47 | #include "bpf_scm.h" | |
48 | ||
1d129d19 JP |
49 | #include "tc_util.h" |
50 | #include "tc_bpf.h" | |
51 | ||
32e93fb7 DB |
52 | #ifdef HAVE_ELF |
53 | static int bpf_obj_open(const char *path, enum bpf_prog_type type, | |
54 | const char *sec, bool verbose); | |
55 | #else | |
56 | static int bpf_obj_open(const char *path, enum bpf_prog_type type, | |
57 | const char *sec, bool verbose) | |
58 | { | |
59 | fprintf(stderr, "No ELF library support compiled in.\n"); | |
60 | errno = ENOSYS; | |
61 | return -1; | |
62 | } | |
63 | #endif | |
64 | ||
65 | static inline __u64 bpf_ptr_to_u64(const void *ptr) | |
66 | { | |
67 | return (__u64)(unsigned long)ptr; | |
68 | } | |
69 | ||
70 | static int bpf(int cmd, union bpf_attr *attr, unsigned int size) | |
71 | { | |
72 | #ifdef __NR_bpf | |
73 | return syscall(__NR_bpf, cmd, attr, size); | |
74 | #else | |
75 | fprintf(stderr, "No bpf syscall, kernel headers too old?\n"); | |
76 | errno = ENOSYS; | |
77 | return -1; | |
78 | #endif | |
79 | } | |
80 | ||
91d88eeb DB |
81 | static int bpf_map_update(int fd, const void *key, const void *value, |
82 | uint64_t flags) | |
32e93fb7 DB |
83 | { |
84 | union bpf_attr attr = { | |
91d88eeb DB |
85 | .map_fd = fd, |
86 | .key = bpf_ptr_to_u64(key), | |
87 | .value = bpf_ptr_to_u64(value), | |
88 | .flags = flags, | |
32e93fb7 DB |
89 | }; |
90 | ||
91d88eeb | 91 | return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); |
32e93fb7 DB |
92 | } |
93 | ||
94 | static int bpf_parse_string(char *arg, bool from_file, __u16 *bpf_len, | |
95 | char **bpf_string, bool *need_release, | |
96 | const char separator) | |
1d129d19 JP |
97 | { |
98 | char sp; | |
99 | ||
100 | if (from_file) { | |
101 | size_t tmp_len, op_len = sizeof("65535 255 255 4294967295,"); | |
102 | char *tmp_string; | |
103 | FILE *fp; | |
104 | ||
105 | tmp_len = sizeof("4096,") + BPF_MAXINSNS * op_len; | |
106 | tmp_string = malloc(tmp_len); | |
107 | if (tmp_string == NULL) | |
108 | return -ENOMEM; | |
109 | ||
110 | memset(tmp_string, 0, tmp_len); | |
111 | ||
112 | fp = fopen(arg, "r"); | |
113 | if (fp == NULL) { | |
114 | perror("Cannot fopen"); | |
115 | free(tmp_string); | |
116 | return -ENOENT; | |
117 | } | |
118 | ||
119 | if (!fgets(tmp_string, tmp_len, fp)) { | |
120 | free(tmp_string); | |
121 | fclose(fp); | |
122 | return -EIO; | |
123 | } | |
124 | ||
125 | fclose(fp); | |
126 | ||
127 | *need_release = true; | |
128 | *bpf_string = tmp_string; | |
129 | } else { | |
130 | *need_release = false; | |
131 | *bpf_string = arg; | |
132 | } | |
133 | ||
134 | if (sscanf(*bpf_string, "%hu%c", bpf_len, &sp) != 2 || | |
135 | sp != separator) { | |
136 | if (*need_release) | |
137 | free(*bpf_string); | |
138 | return -EINVAL; | |
139 | } | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
32e93fb7 DB |
144 | static int bpf_ops_parse(int argc, char **argv, struct sock_filter *bpf_ops, |
145 | bool from_file) | |
1d129d19 JP |
146 | { |
147 | char *bpf_string, *token, separator = ','; | |
148 | int ret = 0, i = 0; | |
149 | bool need_release; | |
150 | __u16 bpf_len = 0; | |
151 | ||
152 | if (argc < 1) | |
153 | return -EINVAL; | |
154 | if (bpf_parse_string(argv[0], from_file, &bpf_len, &bpf_string, | |
155 | &need_release, separator)) | |
156 | return -EINVAL; | |
157 | if (bpf_len == 0 || bpf_len > BPF_MAXINSNS) { | |
158 | ret = -EINVAL; | |
159 | goto out; | |
160 | } | |
161 | ||
162 | token = bpf_string; | |
163 | while ((token = strchr(token, separator)) && (++token)[0]) { | |
164 | if (i >= bpf_len) { | |
165 | fprintf(stderr, "Real program length exceeds encoded " | |
166 | "length parameter!\n"); | |
167 | ret = -EINVAL; | |
168 | goto out; | |
169 | } | |
170 | ||
171 | if (sscanf(token, "%hu %hhu %hhu %u,", | |
172 | &bpf_ops[i].code, &bpf_ops[i].jt, | |
173 | &bpf_ops[i].jf, &bpf_ops[i].k) != 4) { | |
174 | fprintf(stderr, "Error at instruction %d!\n", i); | |
175 | ret = -EINVAL; | |
176 | goto out; | |
177 | } | |
178 | ||
179 | i++; | |
180 | } | |
181 | ||
182 | if (i != bpf_len) { | |
183 | fprintf(stderr, "Parsed program length is less than encoded" | |
184 | "length parameter!\n"); | |
185 | ret = -EINVAL; | |
186 | goto out; | |
187 | } | |
188 | ret = bpf_len; | |
1d129d19 JP |
189 | out: |
190 | if (need_release) | |
191 | free(bpf_string); | |
192 | ||
193 | return ret; | |
194 | } | |
195 | ||
196 | void bpf_print_ops(FILE *f, struct rtattr *bpf_ops, __u16 len) | |
197 | { | |
198 | struct sock_filter *ops = (struct sock_filter *) RTA_DATA(bpf_ops); | |
199 | int i; | |
200 | ||
201 | if (len == 0) | |
202 | return; | |
203 | ||
204 | fprintf(f, "bytecode \'%u,", len); | |
205 | ||
206 | for (i = 0; i < len - 1; i++) | |
207 | fprintf(f, "%hu %hhu %hhu %u,", ops[i].code, ops[i].jt, | |
208 | ops[i].jf, ops[i].k); | |
209 | ||
6256f8c9 | 210 | fprintf(f, "%hu %hhu %hhu %u\'", ops[i].code, ops[i].jt, |
1d129d19 JP |
211 | ops[i].jf, ops[i].k); |
212 | } | |
11c39b5e | 213 | |
91d88eeb DB |
214 | static int bpf_map_selfcheck_pinned(int fd, const struct bpf_elf_map *map, |
215 | int length) | |
9e607f2e DB |
216 | { |
217 | char file[PATH_MAX], buff[4096]; | |
218 | struct bpf_elf_map tmp, zero; | |
219 | unsigned int val; | |
220 | FILE *fp; | |
221 | ||
222 | snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd); | |
223 | ||
224 | fp = fopen(file, "r"); | |
225 | if (!fp) { | |
226 | fprintf(stderr, "No procfs support?!\n"); | |
227 | return -EIO; | |
228 | } | |
229 | ||
230 | memset(&tmp, 0, sizeof(tmp)); | |
231 | while (fgets(buff, sizeof(buff), fp)) { | |
232 | if (sscanf(buff, "map_type:\t%u", &val) == 1) | |
233 | tmp.type = val; | |
234 | else if (sscanf(buff, "key_size:\t%u", &val) == 1) | |
235 | tmp.size_key = val; | |
236 | else if (sscanf(buff, "value_size:\t%u", &val) == 1) | |
237 | tmp.size_value = val; | |
238 | else if (sscanf(buff, "max_entries:\t%u", &val) == 1) | |
239 | tmp.max_elem = val; | |
240 | } | |
241 | ||
242 | fclose(fp); | |
243 | ||
91d88eeb | 244 | if (!memcmp(&tmp, map, length)) { |
9e607f2e DB |
245 | return 0; |
246 | } else { | |
247 | memset(&zero, 0, sizeof(zero)); | |
248 | /* If kernel doesn't have eBPF-related fdinfo, we cannot do much, | |
249 | * so just accept it. We know we do have an eBPF fd and in this | |
250 | * case, everything is 0. It is guaranteed that no such map exists | |
251 | * since map type of 0 is unloadable BPF_MAP_TYPE_UNSPEC. | |
252 | */ | |
91d88eeb | 253 | if (!memcmp(&tmp, &zero, length)) |
9e607f2e DB |
254 | return 0; |
255 | ||
256 | fprintf(stderr, "Map specs from pinned file differ!\n"); | |
257 | return -EINVAL; | |
258 | } | |
259 | } | |
260 | ||
91d88eeb DB |
261 | static int bpf_mnt_fs(const char *target) |
262 | { | |
263 | bool bind_done = false; | |
264 | ||
265 | while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) { | |
266 | if (errno != EINVAL || bind_done) { | |
267 | fprintf(stderr, "mount --make-private %s failed: %s\n", | |
268 | target, strerror(errno)); | |
269 | return -1; | |
270 | } | |
271 | ||
272 | if (mount(target, target, "none", MS_BIND, NULL)) { | |
273 | fprintf(stderr, "mount --bind %s %s failed: %s\n", | |
274 | target, target, strerror(errno)); | |
275 | return -1; | |
276 | } | |
277 | ||
278 | bind_done = true; | |
279 | } | |
280 | ||
281 | if (mount("bpf", target, "bpf", 0, NULL)) { | |
282 | fprintf(stderr, "mount -t bpf bpf %s failed: %s\n", | |
283 | target, strerror(errno)); | |
284 | return -1; | |
285 | } | |
286 | ||
287 | return 0; | |
288 | } | |
289 | ||
32e93fb7 DB |
290 | static int bpf_valid_mntpt(const char *mnt, unsigned long magic) |
291 | { | |
292 | struct statfs st_fs; | |
293 | ||
294 | if (statfs(mnt, &st_fs) < 0) | |
295 | return -ENOENT; | |
296 | if ((unsigned long)st_fs.f_type != magic) | |
297 | return -ENOENT; | |
298 | ||
299 | return 0; | |
300 | } | |
301 | ||
302 | static const char *bpf_find_mntpt(const char *fstype, unsigned long magic, | |
303 | char *mnt, int len, | |
304 | const char * const *known_mnts) | |
305 | { | |
306 | const char * const *ptr; | |
307 | char type[100]; | |
308 | FILE *fp; | |
309 | ||
310 | if (known_mnts) { | |
311 | ptr = known_mnts; | |
312 | while (*ptr) { | |
313 | if (bpf_valid_mntpt(*ptr, magic) == 0) { | |
314 | strncpy(mnt, *ptr, len - 1); | |
315 | mnt[len - 1] = 0; | |
316 | return mnt; | |
317 | } | |
318 | ptr++; | |
319 | } | |
320 | } | |
321 | ||
322 | fp = fopen("/proc/mounts", "r"); | |
323 | if (fp == NULL || len != PATH_MAX) | |
324 | return NULL; | |
325 | ||
326 | while (fscanf(fp, "%*s %" textify(PATH_MAX) "s %99s %*s %*d %*d\n", | |
327 | mnt, type) == 2) { | |
328 | if (strcmp(type, fstype) == 0) | |
329 | break; | |
330 | } | |
331 | ||
332 | fclose(fp); | |
333 | if (strcmp(type, fstype) != 0) | |
334 | return NULL; | |
335 | ||
336 | return mnt; | |
337 | } | |
338 | ||
339 | int bpf_trace_pipe(void) | |
340 | { | |
341 | char tracefs_mnt[PATH_MAX] = TRACE_DIR_MNT; | |
342 | static const char * const tracefs_known_mnts[] = { | |
343 | TRACE_DIR_MNT, | |
344 | "/sys/kernel/debug/tracing", | |
345 | "/tracing", | |
346 | "/trace", | |
347 | 0, | |
348 | }; | |
349 | char tpipe[PATH_MAX]; | |
350 | const char *mnt; | |
351 | int fd; | |
352 | ||
353 | mnt = bpf_find_mntpt("tracefs", TRACEFS_MAGIC, tracefs_mnt, | |
354 | sizeof(tracefs_mnt), tracefs_known_mnts); | |
355 | if (!mnt) { | |
356 | fprintf(stderr, "tracefs not mounted?\n"); | |
357 | return -1; | |
358 | } | |
359 | ||
360 | snprintf(tpipe, sizeof(tpipe), "%s/trace_pipe", mnt); | |
361 | ||
362 | fd = open(tpipe, O_RDONLY); | |
363 | if (fd < 0) | |
364 | return -1; | |
365 | ||
366 | fprintf(stderr, "Running! Hang up with ^C!\n\n"); | |
367 | while (1) { | |
368 | static char buff[4096]; | |
369 | ssize_t ret; | |
370 | ||
371 | ret = read(fd, buff, sizeof(buff) - 1); | |
372 | if (ret > 0) { | |
373 | write(2, buff, ret); | |
374 | fflush(stderr); | |
375 | } | |
376 | } | |
377 | ||
378 | return 0; | |
379 | } | |
380 | ||
91d88eeb DB |
381 | static const char *bpf_get_tc_dir(void) |
382 | { | |
383 | static bool bpf_mnt_cached = false; | |
384 | static char bpf_tc_dir[PATH_MAX]; | |
385 | static const char *mnt; | |
386 | static const char * const bpf_known_mnts[] = { | |
387 | BPF_DIR_MNT, | |
388 | 0, | |
389 | }; | |
390 | char bpf_mnt[PATH_MAX] = BPF_DIR_MNT; | |
391 | char bpf_glo_dir[PATH_MAX]; | |
392 | int ret; | |
393 | ||
394 | if (bpf_mnt_cached) | |
395 | goto done; | |
396 | ||
397 | mnt = bpf_find_mntpt("bpf", BPF_FS_MAGIC, bpf_mnt, sizeof(bpf_mnt), | |
398 | bpf_known_mnts); | |
399 | if (!mnt) { | |
400 | mnt = getenv(BPF_ENV_MNT); | |
401 | if (!mnt) | |
402 | mnt = BPF_DIR_MNT; | |
403 | ret = bpf_mnt_fs(mnt); | |
404 | if (ret) { | |
405 | mnt = NULL; | |
406 | goto out; | |
407 | } | |
408 | } | |
409 | ||
410 | snprintf(bpf_tc_dir, sizeof(bpf_tc_dir), "%s/%s", mnt, BPF_DIR_TC); | |
411 | ret = mkdir(bpf_tc_dir, S_IRWXU); | |
412 | if (ret && errno != EEXIST) { | |
413 | fprintf(stderr, "mkdir %s failed: %s\n", bpf_tc_dir, | |
414 | strerror(errno)); | |
415 | mnt = NULL; | |
416 | goto out; | |
417 | } | |
418 | ||
419 | snprintf(bpf_glo_dir, sizeof(bpf_glo_dir), "%s/%s", | |
420 | bpf_tc_dir, BPF_DIR_GLOBALS); | |
421 | ret = mkdir(bpf_glo_dir, S_IRWXU); | |
422 | if (ret && errno != EEXIST) { | |
423 | fprintf(stderr, "mkdir %s failed: %s\n", bpf_glo_dir, | |
424 | strerror(errno)); | |
425 | mnt = NULL; | |
426 | goto out; | |
427 | } | |
428 | ||
429 | mnt = bpf_tc_dir; | |
430 | out: | |
431 | bpf_mnt_cached = true; | |
432 | done: | |
433 | return mnt; | |
434 | } | |
435 | ||
436 | static int bpf_obj_get(const char *pathname) | |
437 | { | |
438 | union bpf_attr attr; | |
439 | char tmp[PATH_MAX]; | |
440 | ||
441 | if (strlen(pathname) > 2 && pathname[0] == 'm' && | |
442 | pathname[1] == ':' && bpf_get_tc_dir()) { | |
443 | snprintf(tmp, sizeof(tmp), "%s/%s", | |
444 | bpf_get_tc_dir(), pathname + 2); | |
445 | pathname = tmp; | |
446 | } | |
447 | ||
448 | memset(&attr, 0, sizeof(attr)); | |
449 | attr.pathname = bpf_ptr_to_u64(pathname); | |
450 | ||
451 | return bpf(BPF_OBJ_GET, &attr, sizeof(attr)); | |
452 | } | |
453 | ||
6256f8c9 | 454 | const char *bpf_default_section(const enum bpf_prog_type type) |
11c39b5e DB |
455 | { |
456 | switch (type) { | |
457 | case BPF_PROG_TYPE_SCHED_CLS: | |
458 | return ELF_SECTION_CLASSIFIER; | |
6256f8c9 DB |
459 | case BPF_PROG_TYPE_SCHED_ACT: |
460 | return ELF_SECTION_ACTION; | |
11c39b5e DB |
461 | default: |
462 | return NULL; | |
463 | } | |
464 | } | |
465 | ||
91d88eeb DB |
466 | enum bpf_mode { |
467 | CBPF_BYTECODE = 0, | |
468 | CBPF_FILE, | |
469 | EBPF_OBJECT, | |
470 | EBPF_PINNED, | |
471 | __BPF_MODE_MAX, | |
472 | #define BPF_MODE_MAX __BPF_MODE_MAX | |
473 | }; | |
474 | ||
475 | static int bpf_parse(int *ptr_argc, char ***ptr_argv, const bool *opt_tbl, | |
476 | enum bpf_prog_type *type, enum bpf_mode *mode, | |
477 | const char **ptr_object, const char **ptr_section, | |
478 | const char **ptr_uds_name, struct sock_filter *opcodes) | |
32e93fb7 | 479 | { |
32e93fb7 | 480 | const char *file, *section, *uds_name; |
32e93fb7 | 481 | bool verbose = false; |
91d88eeb DB |
482 | int ret, argc; |
483 | char **argv; | |
484 | ||
485 | argv = *ptr_argv; | |
486 | argc = *ptr_argc; | |
487 | ||
488 | if (opt_tbl[CBPF_BYTECODE] && | |
489 | (matches(*argv, "bytecode") == 0 || | |
490 | strcmp(*argv, "bc") == 0)) { | |
491 | *mode = CBPF_BYTECODE; | |
492 | } else if (opt_tbl[CBPF_FILE] && | |
493 | (matches(*argv, "bytecode-file") == 0 || | |
494 | strcmp(*argv, "bcf") == 0)) { | |
495 | *mode = CBPF_FILE; | |
496 | } else if (opt_tbl[EBPF_OBJECT] && | |
497 | (matches(*argv, "object-file") == 0 || | |
498 | strcmp(*argv, "obj") == 0)) { | |
499 | *mode = EBPF_OBJECT; | |
500 | } else if (opt_tbl[EBPF_PINNED] && | |
501 | (matches(*argv, "object-pinned") == 0 || | |
502 | matches(*argv, "pinned") == 0 || | |
503 | matches(*argv, "fd") == 0)) { | |
504 | *mode = EBPF_PINNED; | |
32e93fb7 DB |
505 | } else { |
506 | fprintf(stderr, "What mode is \"%s\"?\n", *argv); | |
507 | return -1; | |
508 | } | |
509 | ||
510 | NEXT_ARG(); | |
511 | file = section = uds_name = NULL; | |
91d88eeb | 512 | if (*mode == EBPF_OBJECT || *mode == EBPF_PINNED) { |
32e93fb7 DB |
513 | file = *argv; |
514 | NEXT_ARG_FWD(); | |
515 | ||
91d88eeb DB |
516 | if (*type == BPF_PROG_TYPE_UNSPEC) { |
517 | if (argc > 0 && matches(*argv, "type") == 0) { | |
518 | NEXT_ARG(); | |
519 | if (matches(*argv, "cls") == 0) { | |
520 | *type = BPF_PROG_TYPE_SCHED_CLS; | |
521 | } else if (matches(*argv, "act") == 0) { | |
522 | *type = BPF_PROG_TYPE_SCHED_ACT; | |
523 | } else { | |
524 | fprintf(stderr, "What type is \"%s\"?\n", | |
525 | *argv); | |
526 | return -1; | |
527 | } | |
528 | NEXT_ARG_FWD(); | |
529 | } else { | |
530 | *type = BPF_PROG_TYPE_SCHED_CLS; | |
531 | } | |
532 | } | |
533 | ||
534 | section = bpf_default_section(*type); | |
32e93fb7 DB |
535 | if (argc > 0 && matches(*argv, "section") == 0) { |
536 | NEXT_ARG(); | |
537 | section = *argv; | |
538 | NEXT_ARG_FWD(); | |
539 | } | |
540 | ||
541 | uds_name = getenv(BPF_ENV_UDS); | |
542 | if (argc > 0 && !uds_name && | |
543 | matches(*argv, "export") == 0) { | |
544 | NEXT_ARG(); | |
545 | uds_name = *argv; | |
546 | NEXT_ARG_FWD(); | |
547 | } | |
548 | ||
549 | if (argc > 0 && matches(*argv, "verbose") == 0) { | |
550 | verbose = true; | |
551 | NEXT_ARG_FWD(); | |
552 | } | |
553 | ||
554 | PREV_ARG(); | |
555 | } | |
556 | ||
91d88eeb DB |
557 | if (*mode == CBPF_BYTECODE || *mode == CBPF_FILE) |
558 | ret = bpf_ops_parse(argc, argv, opcodes, *mode == CBPF_FILE); | |
559 | else if (*mode == EBPF_OBJECT) | |
560 | ret = bpf_obj_open(file, *type, section, verbose); | |
561 | else if (*mode == EBPF_PINNED) | |
32e93fb7 | 562 | ret = bpf_obj_get(file); |
91d88eeb | 563 | else |
32e93fb7 DB |
564 | return -1; |
565 | ||
91d88eeb DB |
566 | if (ptr_object) |
567 | *ptr_object = file; | |
568 | if (ptr_section) | |
569 | *ptr_section = section; | |
570 | if (ptr_uds_name) | |
571 | *ptr_uds_name = uds_name; | |
572 | ||
573 | *ptr_argc = argc; | |
574 | *ptr_argv = argv; | |
575 | ||
576 | return ret; | |
577 | } | |
578 | ||
579 | int bpf_parse_common(int *ptr_argc, char ***ptr_argv, const int *nla_tbl, | |
580 | enum bpf_prog_type type, const char **ptr_object, | |
581 | const char **ptr_uds_name, struct nlmsghdr *n) | |
582 | { | |
583 | struct sock_filter opcodes[BPF_MAXINSNS]; | |
584 | const bool opt_tbl[BPF_MODE_MAX] = { | |
585 | [CBPF_BYTECODE] = true, | |
586 | [CBPF_FILE] = true, | |
587 | [EBPF_OBJECT] = true, | |
588 | [EBPF_PINNED] = true, | |
589 | }; | |
590 | char annotation[256]; | |
591 | const char *section; | |
592 | enum bpf_mode mode; | |
593 | int ret; | |
594 | ||
595 | ret = bpf_parse(ptr_argc, ptr_argv, opt_tbl, &type, &mode, | |
596 | ptr_object, §ion, ptr_uds_name, opcodes); | |
597 | if (ret < 0) | |
598 | return ret; | |
599 | ||
32e93fb7 DB |
600 | if (mode == CBPF_BYTECODE || mode == CBPF_FILE) { |
601 | addattr16(n, MAX_MSG, nla_tbl[BPF_NLA_OPS_LEN], ret); | |
602 | addattr_l(n, MAX_MSG, nla_tbl[BPF_NLA_OPS], opcodes, | |
603 | ret * sizeof(struct sock_filter)); | |
91d88eeb DB |
604 | } |
605 | ||
606 | if (mode == EBPF_OBJECT || mode == EBPF_PINNED) { | |
32e93fb7 | 607 | snprintf(annotation, sizeof(annotation), "%s:[%s]", |
91d88eeb DB |
608 | basename(*ptr_object), mode == EBPF_PINNED ? |
609 | "*fsobj" : section); | |
32e93fb7 DB |
610 | |
611 | addattr32(n, MAX_MSG, nla_tbl[BPF_NLA_FD], ret); | |
612 | addattrstrz(n, MAX_MSG, nla_tbl[BPF_NLA_NAME], annotation); | |
613 | } | |
614 | ||
91d88eeb DB |
615 | return 0; |
616 | } | |
32e93fb7 | 617 | |
91d88eeb DB |
618 | int bpf_graft_map(const char *map_path, uint32_t *key, int argc, char **argv) |
619 | { | |
620 | enum bpf_prog_type type = BPF_PROG_TYPE_UNSPEC; | |
621 | const bool opt_tbl[BPF_MODE_MAX] = { | |
622 | [CBPF_BYTECODE] = false, | |
623 | [CBPF_FILE] = false, | |
624 | [EBPF_OBJECT] = true, | |
625 | [EBPF_PINNED] = true, | |
626 | }; | |
627 | const struct bpf_elf_map test = { | |
628 | .type = BPF_MAP_TYPE_PROG_ARRAY, | |
629 | .size_key = sizeof(int), | |
630 | .size_value = sizeof(int), | |
631 | }; | |
632 | int ret, prog_fd, map_fd; | |
633 | const char *section; | |
634 | enum bpf_mode mode; | |
635 | uint32_t map_key; | |
636 | ||
637 | prog_fd = bpf_parse(&argc, &argv, opt_tbl, &type, &mode, | |
638 | NULL, §ion, NULL, NULL); | |
639 | if (prog_fd < 0) | |
640 | return prog_fd; | |
641 | if (key) { | |
642 | map_key = *key; | |
643 | } else { | |
644 | ret = sscanf(section, "%*i/%i", &map_key); | |
645 | if (ret != 1) { | |
646 | fprintf(stderr, "Couldn\'t infer map key from section " | |
647 | "name! Please provide \'key\' argument!\n"); | |
648 | ret = -EINVAL; | |
649 | goto out_prog; | |
650 | } | |
651 | } | |
32e93fb7 | 652 | |
91d88eeb DB |
653 | map_fd = bpf_obj_get(map_path); |
654 | if (map_fd < 0) { | |
655 | fprintf(stderr, "Couldn\'t retrieve pinned map \'%s\': %s\n", | |
656 | map_path, strerror(errno)); | |
657 | ret = map_fd; | |
658 | goto out_prog; | |
659 | } | |
660 | ||
661 | ret = bpf_map_selfcheck_pinned(map_fd, &test, | |
662 | offsetof(struct bpf_elf_map, max_elem)); | |
663 | if (ret < 0) { | |
664 | fprintf(stderr, "Map \'%s\' self-check failed!\n", map_path); | |
665 | goto out_map; | |
666 | } | |
667 | ||
668 | ret = bpf_map_update(map_fd, &map_key, &prog_fd, BPF_ANY); | |
669 | if (ret < 0) | |
670 | fprintf(stderr, "Map update failed: %s\n", strerror(errno)); | |
671 | out_map: | |
672 | close(map_fd); | |
673 | out_prog: | |
674 | close(prog_fd); | |
675 | return ret; | |
32e93fb7 DB |
676 | } |
677 | ||
6256f8c9 | 678 | #ifdef HAVE_ELF |
32e93fb7 DB |
679 | struct bpf_elf_prog { |
680 | enum bpf_prog_type type; | |
681 | const struct bpf_insn *insns; | |
682 | size_t size; | |
683 | const char *license; | |
684 | }; | |
685 | ||
f6793eec DB |
686 | struct bpf_hash_entry { |
687 | unsigned int pinning; | |
688 | const char *subpath; | |
689 | struct bpf_hash_entry *next; | |
690 | }; | |
691 | ||
32e93fb7 DB |
692 | struct bpf_elf_ctx { |
693 | Elf *elf_fd; | |
694 | GElf_Ehdr elf_hdr; | |
695 | Elf_Data *sym_tab; | |
696 | Elf_Data *str_tab; | |
697 | int obj_fd; | |
698 | int map_fds[ELF_MAX_MAPS]; | |
699 | struct bpf_elf_map maps[ELF_MAX_MAPS]; | |
700 | int sym_num; | |
701 | int map_num; | |
702 | bool *sec_done; | |
703 | int sec_maps; | |
704 | char license[ELF_MAX_LICENSE_LEN]; | |
705 | enum bpf_prog_type type; | |
706 | bool verbose; | |
707 | struct bpf_elf_st stat; | |
f6793eec | 708 | struct bpf_hash_entry *ht[256]; |
32e93fb7 DB |
709 | }; |
710 | ||
6256f8c9 | 711 | struct bpf_elf_sec_data { |
32e93fb7 DB |
712 | GElf_Shdr sec_hdr; |
713 | Elf_Data *sec_data; | |
714 | const char *sec_name; | |
6256f8c9 DB |
715 | }; |
716 | ||
717 | struct bpf_map_data { | |
32e93fb7 DB |
718 | int *fds; |
719 | const char *obj; | |
720 | struct bpf_elf_st *st; | |
721 | struct bpf_elf_map *ent; | |
6256f8c9 DB |
722 | }; |
723 | ||
724 | /* If we provide a small buffer with log level enabled, the kernel | |
725 | * could fail program load as no buffer space is available for the | |
726 | * log and thus verifier fails. In case something doesn't pass the | |
727 | * verifier we still want to hand something descriptive to the user. | |
728 | */ | |
729 | static char bpf_log_buf[65536]; | |
6256f8c9 | 730 | |
32e93fb7 | 731 | static __check_format_string(1, 2) void bpf_dump_error(const char *format, ...) |
11c39b5e DB |
732 | { |
733 | va_list vl; | |
734 | ||
735 | va_start(vl, format); | |
736 | vfprintf(stderr, format, vl); | |
737 | va_end(vl); | |
738 | ||
d937a74b DB |
739 | if (bpf_log_buf[0]) { |
740 | fprintf(stderr, "%s\n", bpf_log_buf); | |
741 | memset(bpf_log_buf, 0, sizeof(bpf_log_buf)); | |
742 | } | |
11c39b5e DB |
743 | } |
744 | ||
32e93fb7 | 745 | static int bpf_map_create(enum bpf_map_type type, unsigned int size_key, |
11c39b5e DB |
746 | unsigned int size_value, unsigned int max_elem) |
747 | { | |
748 | union bpf_attr attr = { | |
749 | .map_type = type, | |
750 | .key_size = size_key, | |
751 | .value_size = size_value, | |
752 | .max_entries = max_elem, | |
753 | }; | |
754 | ||
755 | return bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); | |
756 | } | |
757 | ||
758 | static int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns, | |
32e93fb7 | 759 | size_t size, const char *license) |
11c39b5e DB |
760 | { |
761 | union bpf_attr attr = { | |
762 | .prog_type = type, | |
763 | .insns = bpf_ptr_to_u64(insns), | |
32e93fb7 | 764 | .insn_cnt = size / sizeof(struct bpf_insn), |
11c39b5e DB |
765 | .license = bpf_ptr_to_u64(license), |
766 | .log_buf = bpf_ptr_to_u64(bpf_log_buf), | |
767 | .log_size = sizeof(bpf_log_buf), | |
768 | .log_level = 1, | |
769 | }; | |
770 | ||
32e93fb7 DB |
771 | if (getenv(BPF_ENV_NOLOG)) { |
772 | attr.log_buf = 0; | |
773 | attr.log_size = 0; | |
774 | attr.log_level = 0; | |
775 | } | |
776 | ||
11c39b5e DB |
777 | return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); |
778 | } | |
779 | ||
32e93fb7 | 780 | static int bpf_obj_pin(int fd, const char *pathname) |
11c39b5e | 781 | { |
32e93fb7 DB |
782 | union bpf_attr attr = { |
783 | .pathname = bpf_ptr_to_u64(pathname), | |
784 | .bpf_fd = fd, | |
785 | }; | |
786 | ||
787 | return bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); | |
788 | } | |
11c39b5e | 789 | |
32e93fb7 DB |
790 | static int bpf_obj_hash(const char *object, uint8_t *out, size_t len) |
791 | { | |
792 | struct sockaddr_alg alg = { | |
793 | .salg_family = AF_ALG, | |
794 | .salg_type = "hash", | |
795 | .salg_name = "sha1", | |
796 | }; | |
797 | int ret, cfd, ofd, ffd; | |
798 | struct stat stbuff; | |
799 | ssize_t size; | |
800 | ||
801 | if (!object || len != 20) | |
802 | return -EINVAL; | |
803 | ||
804 | cfd = socket(AF_ALG, SOCK_SEQPACKET, 0); | |
805 | if (cfd < 0) { | |
806 | fprintf(stderr, "Cannot get AF_ALG socket: %s\n", | |
807 | strerror(errno)); | |
808 | return cfd; | |
809 | } | |
810 | ||
811 | ret = bind(cfd, (struct sockaddr *)&alg, sizeof(alg)); | |
812 | if (ret < 0) { | |
813 | fprintf(stderr, "Error binding socket: %s\n", strerror(errno)); | |
814 | goto out_cfd; | |
815 | } | |
816 | ||
817 | ofd = accept(cfd, NULL, 0); | |
818 | if (ofd < 0) { | |
819 | fprintf(stderr, "Error accepting socket: %s\n", | |
820 | strerror(errno)); | |
821 | ret = ofd; | |
822 | goto out_cfd; | |
823 | } | |
824 | ||
825 | ffd = open(object, O_RDONLY); | |
826 | if (ffd < 0) { | |
827 | fprintf(stderr, "Error opening object %s: %s\n", | |
828 | object, strerror(errno)); | |
829 | ret = ffd; | |
830 | goto out_ofd; | |
831 | } | |
832 | ||
833 | ret = fstat(ffd, &stbuff); | |
834 | if (ret < 0) { | |
835 | fprintf(stderr, "Error doing fstat: %s\n", | |
836 | strerror(errno)); | |
837 | goto out_ffd; | |
d937a74b | 838 | } |
11c39b5e | 839 | |
32e93fb7 DB |
840 | size = sendfile(ofd, ffd, NULL, stbuff.st_size); |
841 | if (size != stbuff.st_size) { | |
842 | fprintf(stderr, "Error from sendfile (%zd vs %zu bytes): %s\n", | |
843 | size, stbuff.st_size, strerror(errno)); | |
844 | ret = -1; | |
845 | goto out_ffd; | |
846 | } | |
847 | ||
848 | size = read(ofd, out, len); | |
849 | if (size != len) { | |
850 | fprintf(stderr, "Error from read (%zd vs %zu bytes): %s\n", | |
851 | size, len, strerror(errno)); | |
852 | ret = -1; | |
853 | } else { | |
854 | ret = 0; | |
855 | } | |
856 | out_ffd: | |
857 | close(ffd); | |
858 | out_ofd: | |
859 | close(ofd); | |
860 | out_cfd: | |
861 | close(cfd); | |
862 | return ret; | |
11c39b5e DB |
863 | } |
864 | ||
32e93fb7 | 865 | static const char *bpf_get_obj_uid(const char *pathname) |
11c39b5e | 866 | { |
32e93fb7 DB |
867 | static bool bpf_uid_cached = false; |
868 | static char bpf_uid[64]; | |
869 | uint8_t tmp[20]; | |
870 | int ret; | |
11c39b5e | 871 | |
32e93fb7 DB |
872 | if (bpf_uid_cached) |
873 | goto done; | |
11c39b5e | 874 | |
32e93fb7 DB |
875 | ret = bpf_obj_hash(pathname, tmp, sizeof(tmp)); |
876 | if (ret) { | |
877 | fprintf(stderr, "Object hashing failed!\n"); | |
878 | return NULL; | |
879 | } | |
880 | ||
881 | hexstring_n2a(tmp, sizeof(tmp), bpf_uid, sizeof(bpf_uid)); | |
882 | bpf_uid_cached = true; | |
883 | done: | |
884 | return bpf_uid; | |
11c39b5e DB |
885 | } |
886 | ||
32e93fb7 DB |
887 | static int bpf_init_env(const char *pathname) |
888 | { | |
889 | struct rlimit limit = { | |
890 | .rlim_cur = RLIM_INFINITY, | |
891 | .rlim_max = RLIM_INFINITY, | |
892 | }; | |
893 | ||
894 | /* Don't bother in case we fail! */ | |
895 | setrlimit(RLIMIT_MEMLOCK, &limit); | |
896 | ||
897 | if (!bpf_get_tc_dir()) { | |
898 | fprintf(stderr, "Continuing without mounted eBPF fs. " | |
899 | "Too old kernel?\n"); | |
900 | return 0; | |
901 | } | |
902 | ||
903 | if (!bpf_get_obj_uid(pathname)) | |
904 | return -1; | |
905 | ||
906 | return 0; | |
6256f8c9 DB |
907 | } |
908 | ||
f6793eec DB |
909 | static const char *bpf_custom_pinning(const struct bpf_elf_ctx *ctx, |
910 | uint32_t pinning) | |
911 | { | |
912 | struct bpf_hash_entry *entry; | |
913 | ||
914 | entry = ctx->ht[pinning & (ARRAY_SIZE(ctx->ht) - 1)]; | |
915 | while (entry && entry->pinning != pinning) | |
916 | entry = entry->next; | |
917 | ||
918 | return entry ? entry->subpath : NULL; | |
919 | } | |
920 | ||
921 | static bool bpf_no_pinning(const struct bpf_elf_ctx *ctx, | |
922 | uint32_t pinning) | |
11c39b5e | 923 | { |
32e93fb7 DB |
924 | switch (pinning) { |
925 | case PIN_OBJECT_NS: | |
926 | case PIN_GLOBAL_NS: | |
927 | return false; | |
928 | case PIN_NONE: | |
32e93fb7 | 929 | return true; |
f6793eec DB |
930 | default: |
931 | return !bpf_custom_pinning(ctx, pinning); | |
32e93fb7 DB |
932 | } |
933 | } | |
934 | ||
935 | static void bpf_make_pathname(char *pathname, size_t len, const char *name, | |
f6793eec | 936 | const struct bpf_elf_ctx *ctx, uint32_t pinning) |
32e93fb7 DB |
937 | { |
938 | switch (pinning) { | |
939 | case PIN_OBJECT_NS: | |
940 | snprintf(pathname, len, "%s/%s/%s", bpf_get_tc_dir(), | |
941 | bpf_get_obj_uid(NULL), name); | |
942 | break; | |
943 | case PIN_GLOBAL_NS: | |
944 | snprintf(pathname, len, "%s/%s/%s", bpf_get_tc_dir(), | |
945 | BPF_DIR_GLOBALS, name); | |
946 | break; | |
f6793eec DB |
947 | default: |
948 | snprintf(pathname, len, "%s/../%s/%s", bpf_get_tc_dir(), | |
949 | bpf_custom_pinning(ctx, pinning), name); | |
950 | break; | |
32e93fb7 DB |
951 | } |
952 | } | |
953 | ||
f6793eec DB |
954 | static int bpf_probe_pinned(const char *name, const struct bpf_elf_ctx *ctx, |
955 | uint32_t pinning) | |
32e93fb7 DB |
956 | { |
957 | char pathname[PATH_MAX]; | |
958 | ||
f6793eec | 959 | if (bpf_no_pinning(ctx, pinning) || !bpf_get_tc_dir()) |
32e93fb7 DB |
960 | return 0; |
961 | ||
f6793eec | 962 | bpf_make_pathname(pathname, sizeof(pathname), name, ctx, pinning); |
32e93fb7 DB |
963 | return bpf_obj_get(pathname); |
964 | } | |
965 | ||
f6793eec | 966 | static int bpf_make_obj_path(void) |
32e93fb7 | 967 | { |
f6793eec | 968 | char tmp[PATH_MAX]; |
32e93fb7 DB |
969 | int ret; |
970 | ||
f6793eec DB |
971 | snprintf(tmp, sizeof(tmp), "%s/%s", bpf_get_tc_dir(), |
972 | bpf_get_obj_uid(NULL)); | |
973 | ||
974 | ret = mkdir(tmp, S_IRWXU); | |
975 | if (ret && errno != EEXIST) { | |
976 | fprintf(stderr, "mkdir %s failed: %s\n", tmp, strerror(errno)); | |
977 | return ret; | |
978 | } | |
979 | ||
980 | return 0; | |
981 | } | |
982 | ||
983 | static int bpf_make_custom_path(const char *todo) | |
984 | { | |
985 | char tmp[PATH_MAX], rem[PATH_MAX], *sub; | |
986 | int ret; | |
987 | ||
988 | snprintf(tmp, sizeof(tmp), "%s/../", bpf_get_tc_dir()); | |
989 | snprintf(rem, sizeof(rem), "%s/", todo); | |
990 | sub = strtok(rem, "/"); | |
32e93fb7 | 991 | |
f6793eec DB |
992 | while (sub) { |
993 | if (strlen(tmp) + strlen(sub) + 2 > PATH_MAX) | |
994 | return -EINVAL; | |
995 | ||
996 | strcat(tmp, sub); | |
997 | strcat(tmp, "/"); | |
32e93fb7 | 998 | |
f6793eec | 999 | ret = mkdir(tmp, S_IRWXU); |
32e93fb7 | 1000 | if (ret && errno != EEXIST) { |
f6793eec | 1001 | fprintf(stderr, "mkdir %s failed: %s\n", tmp, |
32e93fb7 DB |
1002 | strerror(errno)); |
1003 | return ret; | |
1004 | } | |
f6793eec DB |
1005 | |
1006 | sub = strtok(NULL, "/"); | |
32e93fb7 DB |
1007 | } |
1008 | ||
f6793eec DB |
1009 | return 0; |
1010 | } | |
1011 | ||
1012 | static int bpf_place_pinned(int fd, const char *name, | |
1013 | const struct bpf_elf_ctx *ctx, uint32_t pinning) | |
1014 | { | |
1015 | char pathname[PATH_MAX]; | |
1016 | const char *tmp; | |
1017 | int ret = 0; | |
1018 | ||
1019 | if (bpf_no_pinning(ctx, pinning) || !bpf_get_tc_dir()) | |
1020 | return 0; | |
1021 | ||
1022 | if (pinning == PIN_OBJECT_NS) | |
1023 | ret = bpf_make_obj_path(); | |
1024 | else if ((tmp = bpf_custom_pinning(ctx, pinning))) | |
1025 | ret = bpf_make_custom_path(tmp); | |
1026 | if (ret < 0) | |
1027 | return ret; | |
1028 | ||
1029 | bpf_make_pathname(pathname, sizeof(pathname), name, ctx, pinning); | |
32e93fb7 DB |
1030 | return bpf_obj_pin(fd, pathname); |
1031 | } | |
1032 | ||
1033 | static int bpf_prog_attach(const char *section, | |
1034 | const struct bpf_elf_prog *prog, bool verbose) | |
1035 | { | |
1036 | int fd; | |
1037 | ||
1038 | /* We can add pinning here later as well, same as bpf_map_attach(). */ | |
1039 | errno = 0; | |
1040 | fd = bpf_prog_load(prog->type, prog->insns, prog->size, | |
1041 | prog->license); | |
1042 | if (fd < 0 || verbose) { | |
1043 | bpf_dump_error("Prog section \'%s\' (type:%u insns:%zu " | |
1044 | "license:\'%s\') %s%s (%d)!\n\n", | |
1045 | section, prog->type, | |
1046 | prog->size / sizeof(struct bpf_insn), | |
fd7f9c7f | 1047 | prog->license, fd < 0 ? "rejected: " : |
32e93fb7 DB |
1048 | "loaded", fd < 0 ? strerror(errno) : "", |
1049 | fd < 0 ? errno : fd); | |
1050 | } | |
1051 | ||
1052 | return fd; | |
1053 | } | |
1054 | ||
1055 | static int bpf_map_attach(const char *name, const struct bpf_elf_map *map, | |
f6793eec | 1056 | const struct bpf_elf_ctx *ctx, bool verbose) |
32e93fb7 DB |
1057 | { |
1058 | int fd, ret; | |
1059 | ||
f6793eec | 1060 | fd = bpf_probe_pinned(name, ctx, map->pinning); |
32e93fb7 | 1061 | if (fd > 0) { |
91d88eeb DB |
1062 | ret = bpf_map_selfcheck_pinned(fd, map, |
1063 | offsetof(struct bpf_elf_map, | |
1064 | id)); | |
9e607f2e DB |
1065 | if (ret < 0) { |
1066 | close(fd); | |
1067 | fprintf(stderr, "Map \'%s\' self-check failed!\n", | |
1068 | name); | |
1069 | return ret; | |
1070 | } | |
32e93fb7 DB |
1071 | if (verbose) |
1072 | fprintf(stderr, "Map \'%s\' loaded as pinned!\n", | |
1073 | name); | |
1074 | return fd; | |
1075 | } | |
1076 | ||
1077 | errno = 0; | |
1078 | fd = bpf_map_create(map->type, map->size_key, map->size_value, | |
1079 | map->max_elem); | |
1080 | if (fd < 0 || verbose) { | |
1081 | bpf_dump_error("Map \'%s\' (type:%u id:%u pinning:%u " | |
1082 | "ksize:%u vsize:%u max-elems:%u) %s%s (%d)!\n", | |
1083 | name, map->type, map->id, map->pinning, | |
1084 | map->size_key, map->size_value, map->max_elem, | |
1085 | fd < 0 ? "rejected: " : "loaded", fd < 0 ? | |
1086 | strerror(errno) : "", fd < 0 ? errno : fd); | |
1087 | if (fd < 0) | |
1088 | return fd; | |
1089 | } | |
1090 | ||
f6793eec | 1091 | ret = bpf_place_pinned(fd, name, ctx, map->pinning); |
32e93fb7 DB |
1092 | if (ret < 0 && errno != EEXIST) { |
1093 | fprintf(stderr, "Could not pin %s map: %s\n", name, | |
1094 | strerror(errno)); | |
1095 | close(fd); | |
1096 | return ret; | |
1097 | } | |
1098 | ||
1099 | return fd; | |
1100 | } | |
1101 | ||
1102 | #define __ELF_ST_BIND(x) ((x) >> 4) | |
1103 | #define __ELF_ST_TYPE(x) (((unsigned int) x) & 0xf) | |
1104 | ||
1105 | static const char *bpf_str_tab_name(const struct bpf_elf_ctx *ctx, | |
1106 | const GElf_Sym *sym) | |
1107 | { | |
1108 | return ctx->str_tab->d_buf + sym->st_name; | |
1109 | } | |
1110 | ||
1111 | static const char *bpf_map_fetch_name(struct bpf_elf_ctx *ctx, int which) | |
1112 | { | |
1113 | GElf_Sym sym; | |
11c39b5e DB |
1114 | int i; |
1115 | ||
32e93fb7 DB |
1116 | for (i = 0; i < ctx->sym_num; i++) { |
1117 | if (gelf_getsym(ctx->sym_tab, i, &sym) != &sym) | |
1118 | continue; | |
1119 | ||
1120 | if (__ELF_ST_BIND(sym.st_info) != STB_GLOBAL || | |
1121 | __ELF_ST_TYPE(sym.st_info) != STT_NOTYPE || | |
1122 | sym.st_shndx != ctx->sec_maps || | |
1123 | sym.st_value / sizeof(struct bpf_elf_map) != which) | |
1124 | continue; | |
1125 | ||
1126 | return bpf_str_tab_name(ctx, &sym); | |
11c39b5e | 1127 | } |
32e93fb7 DB |
1128 | |
1129 | return NULL; | |
11c39b5e DB |
1130 | } |
1131 | ||
32e93fb7 | 1132 | static int bpf_maps_attach_all(struct bpf_elf_ctx *ctx) |
11c39b5e | 1133 | { |
32e93fb7 DB |
1134 | const char *map_name; |
1135 | int i, fd; | |
11c39b5e | 1136 | |
32e93fb7 DB |
1137 | for (i = 0; i < ctx->map_num; i++) { |
1138 | map_name = bpf_map_fetch_name(ctx, i); | |
1139 | if (!map_name) | |
1140 | return -EIO; | |
11c39b5e | 1141 | |
f6793eec DB |
1142 | fd = bpf_map_attach(map_name, &ctx->maps[i], ctx, |
1143 | ctx->verbose); | |
32e93fb7 DB |
1144 | if (fd < 0) |
1145 | return fd; | |
11c39b5e | 1146 | |
32e93fb7 | 1147 | ctx->map_fds[i] = fd; |
11c39b5e DB |
1148 | } |
1149 | ||
1150 | return 0; | |
11c39b5e DB |
1151 | } |
1152 | ||
32e93fb7 DB |
1153 | static int bpf_fill_section_data(struct bpf_elf_ctx *ctx, int section, |
1154 | struct bpf_elf_sec_data *data) | |
11c39b5e | 1155 | { |
32e93fb7 | 1156 | Elf_Data *sec_edata; |
11c39b5e DB |
1157 | GElf_Shdr sec_hdr; |
1158 | Elf_Scn *sec_fd; | |
11c39b5e DB |
1159 | char *sec_name; |
1160 | ||
32e93fb7 | 1161 | memset(data, 0, sizeof(*data)); |
11c39b5e | 1162 | |
32e93fb7 | 1163 | sec_fd = elf_getscn(ctx->elf_fd, section); |
11c39b5e DB |
1164 | if (!sec_fd) |
1165 | return -EINVAL; | |
11c39b5e DB |
1166 | if (gelf_getshdr(sec_fd, &sec_hdr) != &sec_hdr) |
1167 | return -EIO; | |
1168 | ||
32e93fb7 | 1169 | sec_name = elf_strptr(ctx->elf_fd, ctx->elf_hdr.e_shstrndx, |
11c39b5e DB |
1170 | sec_hdr.sh_name); |
1171 | if (!sec_name || !sec_hdr.sh_size) | |
1172 | return -ENOENT; | |
1173 | ||
1174 | sec_edata = elf_getdata(sec_fd, NULL); | |
1175 | if (!sec_edata || elf_getdata(sec_fd, sec_edata)) | |
1176 | return -EIO; | |
1177 | ||
32e93fb7 | 1178 | memcpy(&data->sec_hdr, &sec_hdr, sizeof(sec_hdr)); |
11c39b5e | 1179 | |
32e93fb7 DB |
1180 | data->sec_name = sec_name; |
1181 | data->sec_data = sec_edata; | |
11c39b5e DB |
1182 | return 0; |
1183 | } | |
1184 | ||
32e93fb7 DB |
1185 | static int bpf_fetch_maps(struct bpf_elf_ctx *ctx, int section, |
1186 | struct bpf_elf_sec_data *data) | |
11c39b5e | 1187 | { |
32e93fb7 DB |
1188 | if (data->sec_data->d_size % sizeof(struct bpf_elf_map) != 0) |
1189 | return -EINVAL; | |
11c39b5e | 1190 | |
32e93fb7 DB |
1191 | ctx->map_num = data->sec_data->d_size / sizeof(struct bpf_elf_map); |
1192 | ctx->sec_maps = section; | |
1193 | ctx->sec_done[section] = true; | |
11c39b5e | 1194 | |
32e93fb7 DB |
1195 | if (ctx->map_num > ARRAY_SIZE(ctx->map_fds)) { |
1196 | fprintf(stderr, "Too many BPF maps in ELF section!\n"); | |
1197 | return -ENOMEM; | |
1198 | } | |
11c39b5e | 1199 | |
32e93fb7 DB |
1200 | memcpy(ctx->maps, data->sec_data->d_buf, data->sec_data->d_size); |
1201 | return 0; | |
1202 | } | |
11c39b5e | 1203 | |
32e93fb7 DB |
1204 | static int bpf_fetch_license(struct bpf_elf_ctx *ctx, int section, |
1205 | struct bpf_elf_sec_data *data) | |
1206 | { | |
1207 | if (data->sec_data->d_size > sizeof(ctx->license)) | |
1208 | return -ENOMEM; | |
11c39b5e | 1209 | |
32e93fb7 DB |
1210 | memcpy(ctx->license, data->sec_data->d_buf, data->sec_data->d_size); |
1211 | ctx->sec_done[section] = true; | |
1212 | return 0; | |
1213 | } | |
11c39b5e | 1214 | |
32e93fb7 DB |
1215 | static int bpf_fetch_symtab(struct bpf_elf_ctx *ctx, int section, |
1216 | struct bpf_elf_sec_data *data) | |
1217 | { | |
1218 | ctx->sym_tab = data->sec_data; | |
1219 | ctx->sym_num = data->sec_hdr.sh_size / data->sec_hdr.sh_entsize; | |
1220 | ctx->sec_done[section] = true; | |
11c39b5e DB |
1221 | return 0; |
1222 | } | |
1223 | ||
32e93fb7 DB |
1224 | static int bpf_fetch_strtab(struct bpf_elf_ctx *ctx, int section, |
1225 | struct bpf_elf_sec_data *data) | |
11c39b5e | 1226 | { |
32e93fb7 DB |
1227 | ctx->str_tab = data->sec_data; |
1228 | ctx->sec_done[section] = true; | |
1229 | return 0; | |
1230 | } | |
11c39b5e | 1231 | |
32e93fb7 DB |
1232 | static int bpf_fetch_ancillary(struct bpf_elf_ctx *ctx) |
1233 | { | |
1234 | struct bpf_elf_sec_data data; | |
1235 | int i, ret = -1; | |
11c39b5e | 1236 | |
32e93fb7 DB |
1237 | for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
1238 | ret = bpf_fill_section_data(ctx, i, &data); | |
11c39b5e DB |
1239 | if (ret < 0) |
1240 | continue; | |
1241 | ||
cce3d466 DB |
1242 | if (data.sec_hdr.sh_type == SHT_PROGBITS && |
1243 | !strcmp(data.sec_name, ELF_SECTION_MAPS)) | |
32e93fb7 | 1244 | ret = bpf_fetch_maps(ctx, i, &data); |
cce3d466 DB |
1245 | else if (data.sec_hdr.sh_type == SHT_PROGBITS && |
1246 | !strcmp(data.sec_name, ELF_SECTION_LICENSE)) | |
32e93fb7 | 1247 | ret = bpf_fetch_license(ctx, i, &data); |
cce3d466 DB |
1248 | else if (data.sec_hdr.sh_type == SHT_SYMTAB && |
1249 | !strcmp(data.sec_name, ".symtab")) | |
32e93fb7 DB |
1250 | ret = bpf_fetch_symtab(ctx, i, &data); |
1251 | else if (data.sec_hdr.sh_type == SHT_STRTAB && | |
cce3d466 | 1252 | !strcmp(data.sec_name, ".strtab")) |
32e93fb7 DB |
1253 | ret = bpf_fetch_strtab(ctx, i, &data); |
1254 | if (ret < 0) { | |
1255 | fprintf(stderr, "Error parsing section %d! Perhaps" | |
1256 | "check with readelf -a?\n", i); | |
1257 | break; | |
11c39b5e | 1258 | } |
32e93fb7 DB |
1259 | } |
1260 | ||
1261 | if (ctx->sym_tab && ctx->str_tab && ctx->sec_maps) { | |
1262 | ret = bpf_maps_attach_all(ctx); | |
1263 | if (ret < 0) { | |
1264 | fprintf(stderr, "Error loading maps into kernel!\n"); | |
1265 | return ret; | |
11c39b5e DB |
1266 | } |
1267 | } | |
1268 | ||
1269 | return ret; | |
1270 | } | |
1271 | ||
32e93fb7 | 1272 | static int bpf_fetch_prog(struct bpf_elf_ctx *ctx, const char *section) |
11c39b5e | 1273 | { |
32e93fb7 DB |
1274 | struct bpf_elf_sec_data data; |
1275 | struct bpf_elf_prog prog; | |
1276 | int ret, i, fd = -1; | |
11c39b5e | 1277 | |
32e93fb7 DB |
1278 | for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
1279 | if (ctx->sec_done[i]) | |
11c39b5e DB |
1280 | continue; |
1281 | ||
32e93fb7 | 1282 | ret = bpf_fill_section_data(ctx, i, &data); |
cce3d466 DB |
1283 | if (ret < 0 || |
1284 | !(data.sec_hdr.sh_type == SHT_PROGBITS && | |
1285 | data.sec_hdr.sh_flags & SHF_EXECINSTR && | |
1286 | !strcmp(data.sec_name, section))) | |
11c39b5e DB |
1287 | continue; |
1288 | ||
32e93fb7 DB |
1289 | memset(&prog, 0, sizeof(prog)); |
1290 | prog.type = ctx->type; | |
1291 | prog.insns = data.sec_data->d_buf; | |
1292 | prog.size = data.sec_data->d_size; | |
1293 | prog.license = ctx->license; | |
11c39b5e | 1294 | |
32e93fb7 DB |
1295 | fd = bpf_prog_attach(section, &prog, ctx->verbose); |
1296 | if (fd < 0) | |
11c39b5e DB |
1297 | continue; |
1298 | ||
32e93fb7 | 1299 | ctx->sec_done[i] = true; |
11c39b5e DB |
1300 | break; |
1301 | } | |
1302 | ||
32e93fb7 | 1303 | return fd; |
11c39b5e DB |
1304 | } |
1305 | ||
32e93fb7 DB |
1306 | static int bpf_apply_relo_data(struct bpf_elf_ctx *ctx, |
1307 | struct bpf_elf_sec_data *data_relo, | |
1308 | struct bpf_elf_sec_data *data_insn) | |
11c39b5e | 1309 | { |
32e93fb7 DB |
1310 | Elf_Data *idata = data_insn->sec_data; |
1311 | GElf_Shdr *rhdr = &data_relo->sec_hdr; | |
1312 | int relo_ent, relo_num = rhdr->sh_size / rhdr->sh_entsize; | |
1313 | struct bpf_insn *insns = idata->d_buf; | |
1314 | unsigned int num_insns = idata->d_size / sizeof(*insns); | |
11c39b5e | 1315 | |
32e93fb7 DB |
1316 | for (relo_ent = 0; relo_ent < relo_num; relo_ent++) { |
1317 | unsigned int ioff, rmap; | |
1318 | GElf_Rel relo; | |
1319 | GElf_Sym sym; | |
1320 | ||
1321 | if (gelf_getrel(data_relo->sec_data, relo_ent, &relo) != &relo) | |
1322 | return -EIO; | |
1323 | ||
1324 | ioff = relo.r_offset / sizeof(struct bpf_insn); | |
1325 | if (ioff >= num_insns || | |
1326 | insns[ioff].code != (BPF_LD | BPF_IMM | BPF_DW)) | |
1327 | return -EINVAL; | |
1328 | ||
1329 | if (gelf_getsym(ctx->sym_tab, GELF_R_SYM(relo.r_info), &sym) != &sym) | |
1330 | return -EIO; | |
2486337a DB |
1331 | if (sym.st_shndx != ctx->sec_maps) { |
1332 | fprintf(stderr, "ELF contains non-map related relo data in " | |
1333 | "entry %u pointing to section %u! Compiler bug?!\n", | |
1334 | relo_ent, sym.st_shndx); | |
1335 | return -EIO; | |
1336 | } | |
32e93fb7 DB |
1337 | |
1338 | rmap = sym.st_value / sizeof(struct bpf_elf_map); | |
1339 | if (rmap >= ARRAY_SIZE(ctx->map_fds)) | |
1340 | return -EINVAL; | |
1341 | if (!ctx->map_fds[rmap]) | |
1342 | return -EINVAL; | |
1343 | ||
1344 | if (ctx->verbose) | |
1345 | fprintf(stderr, "Map \'%s\' (%d) injected into prog " | |
1346 | "section \'%s\' at offset %u!\n", | |
1347 | bpf_str_tab_name(ctx, &sym), ctx->map_fds[rmap], | |
1348 | data_insn->sec_name, ioff); | |
11c39b5e | 1349 | |
32e93fb7 DB |
1350 | insns[ioff].src_reg = BPF_PSEUDO_MAP_FD; |
1351 | insns[ioff].imm = ctx->map_fds[rmap]; | |
1352 | } | |
1353 | ||
1354 | return 0; | |
1355 | } | |
1356 | ||
1357 | static int bpf_fetch_prog_relo(struct bpf_elf_ctx *ctx, const char *section) | |
1358 | { | |
1359 | struct bpf_elf_sec_data data_relo, data_insn; | |
1360 | struct bpf_elf_prog prog; | |
1361 | int ret, idx, i, fd = -1; | |
1362 | ||
1363 | for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { | |
1364 | ret = bpf_fill_section_data(ctx, i, &data_relo); | |
1365 | if (ret < 0 || data_relo.sec_hdr.sh_type != SHT_REL) | |
11c39b5e DB |
1366 | continue; |
1367 | ||
32e93fb7 DB |
1368 | idx = data_relo.sec_hdr.sh_info; |
1369 | ret = bpf_fill_section_data(ctx, idx, &data_insn); | |
cce3d466 DB |
1370 | if (ret < 0 || |
1371 | !(data_insn.sec_hdr.sh_type == SHT_PROGBITS && | |
1372 | data_insn.sec_hdr.sh_flags & SHF_EXECINSTR && | |
1373 | !strcmp(data_insn.sec_name, section))) | |
11c39b5e | 1374 | continue; |
32e93fb7 DB |
1375 | |
1376 | ret = bpf_apply_relo_data(ctx, &data_relo, &data_insn); | |
1377 | if (ret < 0) | |
11c39b5e DB |
1378 | continue; |
1379 | ||
32e93fb7 DB |
1380 | memset(&prog, 0, sizeof(prog)); |
1381 | prog.type = ctx->type; | |
1382 | prog.insns = data_insn.sec_data->d_buf; | |
1383 | prog.size = data_insn.sec_data->d_size; | |
1384 | prog.license = ctx->license; | |
1385 | ||
1386 | fd = bpf_prog_attach(section, &prog, ctx->verbose); | |
1387 | if (fd < 0) | |
11c39b5e DB |
1388 | continue; |
1389 | ||
32e93fb7 DB |
1390 | ctx->sec_done[i] = true; |
1391 | ctx->sec_done[idx] = true; | |
11c39b5e DB |
1392 | break; |
1393 | } | |
1394 | ||
32e93fb7 | 1395 | return fd; |
11c39b5e DB |
1396 | } |
1397 | ||
32e93fb7 | 1398 | static int bpf_fetch_prog_sec(struct bpf_elf_ctx *ctx, const char *section) |
473d7840 DB |
1399 | { |
1400 | int ret = -1; | |
1401 | ||
32e93fb7 DB |
1402 | if (ctx->sym_tab) |
1403 | ret = bpf_fetch_prog_relo(ctx, section); | |
473d7840 | 1404 | if (ret < 0) |
32e93fb7 DB |
1405 | ret = bpf_fetch_prog(ctx, section); |
1406 | ||
473d7840 DB |
1407 | return ret; |
1408 | } | |
1409 | ||
910b543d DB |
1410 | static int bpf_find_map_by_id(struct bpf_elf_ctx *ctx, uint32_t id) |
1411 | { | |
1412 | int i; | |
1413 | ||
1414 | for (i = 0; i < ARRAY_SIZE(ctx->map_fds); i++) | |
1415 | if (ctx->map_fds[i] && ctx->maps[i].id == id && | |
1416 | ctx->maps[i].type == BPF_MAP_TYPE_PROG_ARRAY) | |
1417 | return i; | |
1418 | return -1; | |
1419 | } | |
1420 | ||
32e93fb7 | 1421 | static int bpf_fill_prog_arrays(struct bpf_elf_ctx *ctx) |
473d7840 | 1422 | { |
32e93fb7 DB |
1423 | struct bpf_elf_sec_data data; |
1424 | uint32_t map_id, key_id; | |
910b543d | 1425 | int fd, i, ret, idx; |
473d7840 | 1426 | |
32e93fb7 DB |
1427 | for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { |
1428 | if (ctx->sec_done[i]) | |
473d7840 DB |
1429 | continue; |
1430 | ||
32e93fb7 | 1431 | ret = bpf_fill_section_data(ctx, i, &data); |
473d7840 DB |
1432 | if (ret < 0) |
1433 | continue; | |
1434 | ||
910b543d DB |
1435 | ret = sscanf(data.sec_name, "%i/%i", &map_id, &key_id); |
1436 | if (ret != 2) | |
32e93fb7 | 1437 | continue; |
910b543d DB |
1438 | |
1439 | idx = bpf_find_map_by_id(ctx, map_id); | |
1440 | if (idx < 0) | |
473d7840 DB |
1441 | continue; |
1442 | ||
32e93fb7 DB |
1443 | fd = bpf_fetch_prog_sec(ctx, data.sec_name); |
1444 | if (fd < 0) | |
473d7840 DB |
1445 | return -EIO; |
1446 | ||
910b543d DB |
1447 | ret = bpf_map_update(ctx->map_fds[idx], &key_id, |
1448 | &fd, BPF_ANY); | |
473d7840 DB |
1449 | if (ret < 0) |
1450 | return -ENOENT; | |
1451 | ||
32e93fb7 | 1452 | ctx->sec_done[i] = true; |
473d7840 DB |
1453 | } |
1454 | ||
1455 | return 0; | |
1456 | } | |
1457 | ||
32e93fb7 | 1458 | static void bpf_save_finfo(struct bpf_elf_ctx *ctx) |
11c39b5e | 1459 | { |
32e93fb7 DB |
1460 | struct stat st; |
1461 | int ret; | |
11c39b5e | 1462 | |
32e93fb7 | 1463 | memset(&ctx->stat, 0, sizeof(ctx->stat)); |
11c39b5e | 1464 | |
32e93fb7 DB |
1465 | ret = fstat(ctx->obj_fd, &st); |
1466 | if (ret < 0) { | |
1467 | fprintf(stderr, "Stat of elf file failed: %s\n", | |
1468 | strerror(errno)); | |
1469 | return; | |
1470 | } | |
11c39b5e | 1471 | |
32e93fb7 DB |
1472 | ctx->stat.st_dev = st.st_dev; |
1473 | ctx->stat.st_ino = st.st_ino; | |
1474 | } | |
1475 | ||
f6793eec DB |
1476 | static int bpf_read_pin_mapping(FILE *fp, uint32_t *id, char *path) |
1477 | { | |
1478 | char buff[PATH_MAX]; | |
1479 | ||
1480 | while (fgets(buff, sizeof(buff), fp)) { | |
1481 | char *ptr = buff; | |
1482 | ||
1483 | while (*ptr == ' ' || *ptr == '\t') | |
1484 | ptr++; | |
1485 | ||
1486 | if (*ptr == '#' || *ptr == '\n' || *ptr == 0) | |
1487 | continue; | |
1488 | ||
1489 | if (sscanf(ptr, "%i %s\n", id, path) != 2 && | |
1490 | sscanf(ptr, "%i %s #", id, path) != 2) { | |
1491 | strcpy(path, ptr); | |
1492 | return -1; | |
1493 | } | |
1494 | ||
1495 | return 1; | |
1496 | } | |
1497 | ||
1498 | return 0; | |
1499 | } | |
1500 | ||
1501 | static bool bpf_pinning_reserved(uint32_t pinning) | |
1502 | { | |
1503 | switch (pinning) { | |
1504 | case PIN_NONE: | |
1505 | case PIN_OBJECT_NS: | |
1506 | case PIN_GLOBAL_NS: | |
1507 | return true; | |
1508 | default: | |
1509 | return false; | |
1510 | } | |
1511 | } | |
1512 | ||
1513 | static void bpf_hash_init(struct bpf_elf_ctx *ctx, const char *db_file) | |
1514 | { | |
1515 | struct bpf_hash_entry *entry; | |
1516 | char subpath[PATH_MAX]; | |
1517 | uint32_t pinning; | |
1518 | FILE *fp; | |
1519 | int ret; | |
1520 | ||
1521 | fp = fopen(db_file, "r"); | |
1522 | if (!fp) | |
1523 | return; | |
1524 | ||
1525 | memset(subpath, 0, sizeof(subpath)); | |
1526 | while ((ret = bpf_read_pin_mapping(fp, &pinning, subpath))) { | |
1527 | if (ret == -1) { | |
1528 | fprintf(stderr, "Database %s is corrupted at: %s\n", | |
1529 | db_file, subpath); | |
1530 | fclose(fp); | |
1531 | return; | |
1532 | } | |
1533 | ||
1534 | if (bpf_pinning_reserved(pinning)) { | |
1535 | fprintf(stderr, "Database %s, id %u is reserved - " | |
1536 | "ignoring!\n", db_file, pinning); | |
1537 | continue; | |
1538 | } | |
1539 | ||
1540 | entry = malloc(sizeof(*entry)); | |
1541 | if (!entry) { | |
1542 | fprintf(stderr, "No memory left for db entry!\n"); | |
1543 | continue; | |
1544 | } | |
1545 | ||
1546 | entry->pinning = pinning; | |
1547 | entry->subpath = strdup(subpath); | |
1548 | if (!entry->subpath) { | |
1549 | fprintf(stderr, "No memory left for db entry!\n"); | |
1550 | free(entry); | |
1551 | continue; | |
1552 | } | |
1553 | ||
1554 | entry->next = ctx->ht[pinning & (ARRAY_SIZE(ctx->ht) - 1)]; | |
1555 | ctx->ht[pinning & (ARRAY_SIZE(ctx->ht) - 1)] = entry; | |
1556 | } | |
1557 | ||
1558 | fclose(fp); | |
1559 | } | |
1560 | ||
1561 | static void bpf_hash_destroy(struct bpf_elf_ctx *ctx) | |
1562 | { | |
1563 | struct bpf_hash_entry *entry; | |
1564 | int i; | |
1565 | ||
1566 | for (i = 0; i < ARRAY_SIZE(ctx->ht); i++) { | |
1567 | while ((entry = ctx->ht[i]) != NULL) { | |
1568 | ctx->ht[i] = entry->next; | |
1569 | free((char *)entry->subpath); | |
1570 | free(entry); | |
1571 | } | |
1572 | } | |
1573 | } | |
1574 | ||
8187b012 DB |
1575 | static int bpf_elf_check_ehdr(const struct bpf_elf_ctx *ctx) |
1576 | { | |
1577 | if (ctx->elf_hdr.e_type != ET_REL || | |
1578 | ctx->elf_hdr.e_machine != 0 || | |
1579 | ctx->elf_hdr.e_version != EV_CURRENT) { | |
1580 | fprintf(stderr, "ELF format error, ELF file not for eBPF?\n"); | |
1581 | return -EINVAL; | |
1582 | } | |
1583 | ||
1584 | switch (ctx->elf_hdr.e_ident[EI_DATA]) { | |
1585 | default: | |
1586 | fprintf(stderr, "ELF format error, wrong endianness info?\n"); | |
1587 | return -EINVAL; | |
1588 | case ELFDATA2LSB: | |
1589 | if (htons(1) == 1) { | |
1590 | fprintf(stderr, | |
1591 | "We are big endian, eBPF object is little endian!\n"); | |
1592 | return -EIO; | |
1593 | } | |
1594 | break; | |
1595 | case ELFDATA2MSB: | |
1596 | if (htons(1) != 1) { | |
1597 | fprintf(stderr, | |
1598 | "We are little endian, eBPF object is big endian!\n"); | |
1599 | return -EIO; | |
1600 | } | |
1601 | break; | |
1602 | } | |
1603 | ||
1604 | return 0; | |
1605 | } | |
1606 | ||
32e93fb7 DB |
1607 | static int bpf_elf_ctx_init(struct bpf_elf_ctx *ctx, const char *pathname, |
1608 | enum bpf_prog_type type, bool verbose) | |
1609 | { | |
1610 | int ret = -EINVAL; | |
1611 | ||
1612 | if (elf_version(EV_CURRENT) == EV_NONE || | |
1613 | bpf_init_env(pathname)) | |
1614 | return ret; | |
1615 | ||
1616 | memset(ctx, 0, sizeof(*ctx)); | |
1617 | ctx->verbose = verbose; | |
1618 | ctx->type = type; | |
1619 | ||
1620 | ctx->obj_fd = open(pathname, O_RDONLY); | |
1621 | if (ctx->obj_fd < 0) | |
1622 | return ctx->obj_fd; | |
1623 | ||
1624 | ctx->elf_fd = elf_begin(ctx->obj_fd, ELF_C_READ, NULL); | |
1625 | if (!ctx->elf_fd) { | |
11c39b5e | 1626 | ret = -EINVAL; |
32e93fb7 | 1627 | goto out_fd; |
11c39b5e DB |
1628 | } |
1629 | ||
8187b012 DB |
1630 | if (elf_kind(ctx->elf_fd) != ELF_K_ELF) { |
1631 | ret = -EINVAL; | |
1632 | goto out_fd; | |
1633 | } | |
1634 | ||
32e93fb7 DB |
1635 | if (gelf_getehdr(ctx->elf_fd, &ctx->elf_hdr) != |
1636 | &ctx->elf_hdr) { | |
11c39b5e DB |
1637 | ret = -EIO; |
1638 | goto out_elf; | |
1639 | } | |
1640 | ||
8187b012 DB |
1641 | ret = bpf_elf_check_ehdr(ctx); |
1642 | if (ret < 0) | |
1643 | goto out_elf; | |
1644 | ||
32e93fb7 DB |
1645 | ctx->sec_done = calloc(ctx->elf_hdr.e_shnum, |
1646 | sizeof(*(ctx->sec_done))); | |
1647 | if (!ctx->sec_done) { | |
11c39b5e DB |
1648 | ret = -ENOMEM; |
1649 | goto out_elf; | |
1650 | } | |
1651 | ||
32e93fb7 | 1652 | bpf_save_finfo(ctx); |
f6793eec DB |
1653 | bpf_hash_init(ctx, CONFDIR "/bpf_pinning"); |
1654 | ||
32e93fb7 DB |
1655 | return 0; |
1656 | out_elf: | |
1657 | elf_end(ctx->elf_fd); | |
1658 | out_fd: | |
1659 | close(ctx->obj_fd); | |
1660 | return ret; | |
1661 | } | |
d937a74b | 1662 | |
32e93fb7 DB |
1663 | static int bpf_maps_count(struct bpf_elf_ctx *ctx) |
1664 | { | |
1665 | int i, count = 0; | |
11c39b5e | 1666 | |
32e93fb7 DB |
1667 | for (i = 0; i < ARRAY_SIZE(ctx->map_fds); i++) { |
1668 | if (!ctx->map_fds[i]) | |
1669 | break; | |
1670 | count++; | |
1671 | } | |
473d7840 | 1672 | |
32e93fb7 DB |
1673 | return count; |
1674 | } | |
6256f8c9 | 1675 | |
32e93fb7 DB |
1676 | static void bpf_maps_teardown(struct bpf_elf_ctx *ctx) |
1677 | { | |
1678 | int i; | |
1679 | ||
1680 | for (i = 0; i < ARRAY_SIZE(ctx->map_fds); i++) { | |
1681 | if (ctx->map_fds[i]) | |
1682 | close(ctx->map_fds[i]); | |
473d7840 | 1683 | } |
32e93fb7 DB |
1684 | } |
1685 | ||
1686 | static void bpf_elf_ctx_destroy(struct bpf_elf_ctx *ctx, bool failure) | |
1687 | { | |
1688 | if (failure) | |
1689 | bpf_maps_teardown(ctx); | |
473d7840 | 1690 | |
f6793eec | 1691 | bpf_hash_destroy(ctx); |
32e93fb7 DB |
1692 | free(ctx->sec_done); |
1693 | elf_end(ctx->elf_fd); | |
1694 | close(ctx->obj_fd); | |
1695 | } | |
6256f8c9 | 1696 | |
32e93fb7 | 1697 | static struct bpf_elf_ctx __ctx; |
6256f8c9 | 1698 | |
32e93fb7 DB |
1699 | static int bpf_obj_open(const char *pathname, enum bpf_prog_type type, |
1700 | const char *section, bool verbose) | |
1701 | { | |
1702 | struct bpf_elf_ctx *ctx = &__ctx; | |
1703 | int fd = 0, ret; | |
6256f8c9 | 1704 | |
32e93fb7 DB |
1705 | ret = bpf_elf_ctx_init(ctx, pathname, type, verbose); |
1706 | if (ret < 0) { | |
1707 | fprintf(stderr, "Cannot initialize ELF context!\n"); | |
1708 | return ret; | |
1709 | } | |
6256f8c9 | 1710 | |
32e93fb7 DB |
1711 | ret = bpf_fetch_ancillary(ctx); |
1712 | if (ret < 0) { | |
1713 | fprintf(stderr, "Error fetching ELF ancillary data!\n"); | |
1714 | goto out; | |
1715 | } | |
1716 | ||
1717 | fd = bpf_fetch_prog_sec(ctx, section); | |
1718 | if (fd < 0) { | |
1719 | fprintf(stderr, "Error fetching program/map!\n"); | |
1720 | ret = fd; | |
1721 | goto out; | |
1722 | } | |
1723 | ||
1724 | ret = bpf_fill_prog_arrays(ctx); | |
1725 | if (ret < 0) | |
1726 | fprintf(stderr, "Error filling program arrays!\n"); | |
11c39b5e | 1727 | out: |
32e93fb7 DB |
1728 | bpf_elf_ctx_destroy(ctx, ret < 0); |
1729 | if (ret < 0) { | |
1730 | if (fd) | |
1731 | close(fd); | |
1732 | return ret; | |
1733 | } | |
1734 | ||
1735 | return fd; | |
6256f8c9 | 1736 | } |
11c39b5e | 1737 | |
6256f8c9 | 1738 | static int |
4bd62446 DB |
1739 | bpf_map_set_send(int fd, struct sockaddr_un *addr, unsigned int addr_len, |
1740 | const struct bpf_map_data *aux, unsigned int entries) | |
6256f8c9 DB |
1741 | { |
1742 | struct bpf_map_set_msg msg; | |
1743 | int *cmsg_buf, min_fd; | |
1744 | char *amsg_buf; | |
1745 | int i; | |
1746 | ||
1747 | memset(&msg, 0, sizeof(msg)); | |
1748 | ||
1749 | msg.aux.uds_ver = BPF_SCM_AUX_VER; | |
4bd62446 | 1750 | msg.aux.num_ent = entries; |
6256f8c9 DB |
1751 | |
1752 | strncpy(msg.aux.obj_name, aux->obj, sizeof(msg.aux.obj_name)); | |
1753 | memcpy(&msg.aux.obj_st, aux->st, sizeof(msg.aux.obj_st)); | |
1754 | ||
1755 | cmsg_buf = bpf_map_set_init(&msg, addr, addr_len); | |
1756 | amsg_buf = (char *)msg.aux.ent; | |
1757 | ||
4bd62446 | 1758 | for (i = 0; i < entries; i += min_fd) { |
6256f8c9 DB |
1759 | int ret; |
1760 | ||
4bd62446 | 1761 | min_fd = min(BPF_SCM_MAX_FDS * 1U, entries - i); |
6256f8c9 DB |
1762 | bpf_map_set_init_single(&msg, min_fd); |
1763 | ||
1764 | memcpy(cmsg_buf, &aux->fds[i], sizeof(aux->fds[0]) * min_fd); | |
1765 | memcpy(amsg_buf, &aux->ent[i], sizeof(aux->ent[0]) * min_fd); | |
1766 | ||
1767 | ret = sendmsg(fd, &msg.hdr, 0); | |
1768 | if (ret <= 0) | |
1769 | return ret ? : -1; | |
1770 | } | |
1771 | ||
1772 | return 0; | |
11c39b5e DB |
1773 | } |
1774 | ||
4bd62446 DB |
1775 | static int |
1776 | bpf_map_set_recv(int fd, int *fds, struct bpf_map_aux *aux, | |
1777 | unsigned int entries) | |
1778 | { | |
1779 | struct bpf_map_set_msg msg; | |
1780 | int *cmsg_buf, min_fd; | |
1781 | char *amsg_buf, *mmsg_buf; | |
1782 | unsigned int needed = 1; | |
1783 | int i; | |
1784 | ||
1785 | cmsg_buf = bpf_map_set_init(&msg, NULL, 0); | |
1786 | amsg_buf = (char *)msg.aux.ent; | |
1787 | mmsg_buf = (char *)&msg.aux; | |
1788 | ||
1789 | for (i = 0; i < min(entries, needed); i += min_fd) { | |
1790 | struct cmsghdr *cmsg; | |
1791 | int ret; | |
1792 | ||
1793 | min_fd = min(entries, entries - i); | |
1794 | bpf_map_set_init_single(&msg, min_fd); | |
1795 | ||
1796 | ret = recvmsg(fd, &msg.hdr, 0); | |
1797 | if (ret <= 0) | |
1798 | return ret ? : -1; | |
1799 | ||
1800 | cmsg = CMSG_FIRSTHDR(&msg.hdr); | |
1801 | if (!cmsg || cmsg->cmsg_type != SCM_RIGHTS) | |
1802 | return -EINVAL; | |
1803 | if (msg.hdr.msg_flags & MSG_CTRUNC) | |
1804 | return -EIO; | |
1805 | if (msg.aux.uds_ver != BPF_SCM_AUX_VER) | |
1806 | return -ENOSYS; | |
1807 | ||
1808 | min_fd = (cmsg->cmsg_len - sizeof(*cmsg)) / sizeof(fd); | |
1809 | if (min_fd > entries || min_fd <= 0) | |
1810 | return -EINVAL; | |
1811 | ||
1812 | memcpy(&fds[i], cmsg_buf, sizeof(fds[0]) * min_fd); | |
1813 | memcpy(&aux->ent[i], amsg_buf, sizeof(aux->ent[0]) * min_fd); | |
1814 | memcpy(aux, mmsg_buf, offsetof(struct bpf_map_aux, ent)); | |
1815 | ||
1816 | needed = aux->num_ent; | |
1817 | } | |
1818 | ||
1819 | return 0; | |
1820 | } | |
1821 | ||
1822 | int bpf_send_map_fds(const char *path, const char *obj) | |
6256f8c9 | 1823 | { |
32e93fb7 | 1824 | struct bpf_elf_ctx *ctx = &__ctx; |
6256f8c9 DB |
1825 | struct sockaddr_un addr; |
1826 | struct bpf_map_data bpf_aux; | |
1827 | int fd, ret; | |
1828 | ||
1829 | fd = socket(AF_UNIX, SOCK_DGRAM, 0); | |
1830 | if (fd < 0) { | |
1831 | fprintf(stderr, "Cannot open socket: %s\n", | |
1832 | strerror(errno)); | |
1833 | return -1; | |
1834 | } | |
1835 | ||
1836 | memset(&addr, 0, sizeof(addr)); | |
1837 | addr.sun_family = AF_UNIX; | |
1838 | strncpy(addr.sun_path, path, sizeof(addr.sun_path)); | |
1839 | ||
1840 | ret = connect(fd, (struct sockaddr *)&addr, sizeof(addr)); | |
1841 | if (ret < 0) { | |
1842 | fprintf(stderr, "Cannot connect to %s: %s\n", | |
1843 | path, strerror(errno)); | |
1844 | return -1; | |
1845 | } | |
1846 | ||
1847 | memset(&bpf_aux, 0, sizeof(bpf_aux)); | |
1848 | ||
32e93fb7 DB |
1849 | bpf_aux.fds = ctx->map_fds; |
1850 | bpf_aux.ent = ctx->maps; | |
1851 | bpf_aux.st = &ctx->stat; | |
6256f8c9 | 1852 | bpf_aux.obj = obj; |
6256f8c9 | 1853 | |
4bd62446 | 1854 | ret = bpf_map_set_send(fd, &addr, sizeof(addr), &bpf_aux, |
32e93fb7 | 1855 | bpf_maps_count(ctx)); |
6256f8c9 | 1856 | if (ret < 0) |
4bd62446 DB |
1857 | fprintf(stderr, "Cannot send fds to %s: %s\n", |
1858 | path, strerror(errno)); | |
1859 | ||
32e93fb7 | 1860 | bpf_maps_teardown(ctx); |
4bd62446 DB |
1861 | close(fd); |
1862 | return ret; | |
1863 | } | |
1864 | ||
1865 | int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux, | |
1866 | unsigned int entries) | |
1867 | { | |
1868 | struct sockaddr_un addr; | |
1869 | int fd, ret; | |
1870 | ||
1871 | fd = socket(AF_UNIX, SOCK_DGRAM, 0); | |
1872 | if (fd < 0) { | |
1873 | fprintf(stderr, "Cannot open socket: %s\n", | |
1874 | strerror(errno)); | |
1875 | return -1; | |
1876 | } | |
1877 | ||
1878 | memset(&addr, 0, sizeof(addr)); | |
1879 | addr.sun_family = AF_UNIX; | |
1880 | strncpy(addr.sun_path, path, sizeof(addr.sun_path)); | |
1881 | ||
1882 | ret = bind(fd, (struct sockaddr *)&addr, sizeof(addr)); | |
1883 | if (ret < 0) { | |
1884 | fprintf(stderr, "Cannot bind to socket: %s\n", | |
1885 | strerror(errno)); | |
1886 | return -1; | |
1887 | } | |
1888 | ||
1889 | ret = bpf_map_set_recv(fd, fds, aux, entries); | |
1890 | if (ret < 0) | |
1891 | fprintf(stderr, "Cannot recv fds from %s: %s\n", | |
6256f8c9 DB |
1892 | path, strerror(errno)); |
1893 | ||
4bd62446 | 1894 | unlink(addr.sun_path); |
6256f8c9 DB |
1895 | close(fd); |
1896 | return ret; | |
1897 | } | |
11c39b5e | 1898 | #endif /* HAVE_ELF */ |