xref: /linux/tools/bpf/bpftool/prog.c (revision b2d0f5d5dc53532e6f07bc546a476a55ebdfe0f3)
1 /*
2  * Copyright (C) 2017 Netronome Systems, Inc.
3  *
4  * This software is dual licensed under the GNU General License Version 2,
5  * June 1991 as shown in the file COPYING in the top-level directory of this
6  * source tree or the BSD 2-Clause License provided below.  You have the
7  * option to license this software under the complete terms of either license.
8  *
9  * The BSD 2-Clause License:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      1. Redistributions of source code must retain the above
16  *         copyright notice, this list of conditions and the following
17  *         disclaimer.
18  *
19  *      2. Redistributions in binary form must reproduce the above
20  *         copyright notice, this list of conditions and the following
21  *         disclaimer in the documentation and/or other materials
22  *         provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 /* Author: Jakub Kicinski <kubakici@wp.pl> */
35 
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <time.h>
43 #include <unistd.h>
44 #include <net/if.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 
48 #include <bpf.h>
49 
50 #include "main.h"
51 #include "disasm.h"
52 
53 static const char * const prog_type_name[] = {
54 	[BPF_PROG_TYPE_UNSPEC]		= "unspec",
55 	[BPF_PROG_TYPE_SOCKET_FILTER]	= "socket_filter",
56 	[BPF_PROG_TYPE_KPROBE]		= "kprobe",
57 	[BPF_PROG_TYPE_SCHED_CLS]	= "sched_cls",
58 	[BPF_PROG_TYPE_SCHED_ACT]	= "sched_act",
59 	[BPF_PROG_TYPE_TRACEPOINT]	= "tracepoint",
60 	[BPF_PROG_TYPE_XDP]		= "xdp",
61 	[BPF_PROG_TYPE_PERF_EVENT]	= "perf_event",
62 	[BPF_PROG_TYPE_CGROUP_SKB]	= "cgroup_skb",
63 	[BPF_PROG_TYPE_CGROUP_SOCK]	= "cgroup_sock",
64 	[BPF_PROG_TYPE_LWT_IN]		= "lwt_in",
65 	[BPF_PROG_TYPE_LWT_OUT]		= "lwt_out",
66 	[BPF_PROG_TYPE_LWT_XMIT]	= "lwt_xmit",
67 	[BPF_PROG_TYPE_SOCK_OPS]	= "sock_ops",
68 	[BPF_PROG_TYPE_SK_SKB]		= "sk_skb",
69 };
70 
71 static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
72 {
73 	struct timespec real_time_ts, boot_time_ts;
74 	time_t wallclock_secs;
75 	struct tm load_tm;
76 
77 	buf[--size] = '\0';
78 
79 	if (clock_gettime(CLOCK_REALTIME, &real_time_ts) ||
80 	    clock_gettime(CLOCK_BOOTTIME, &boot_time_ts)) {
81 		perror("Can't read clocks");
82 		snprintf(buf, size, "%llu", nsecs / 1000000000);
83 		return;
84 	}
85 
86 	wallclock_secs = (real_time_ts.tv_sec - boot_time_ts.tv_sec) +
87 		nsecs / 1000000000;
88 
89 	if (!localtime_r(&wallclock_secs, &load_tm)) {
90 		snprintf(buf, size, "%llu", nsecs / 1000000000);
91 		return;
92 	}
93 
94 	strftime(buf, size, "%b %d/%H:%M", &load_tm);
95 }
96 
97 static int prog_fd_by_tag(unsigned char *tag)
98 {
99 	struct bpf_prog_info info = {};
100 	__u32 len = sizeof(info);
101 	unsigned int id = 0;
102 	int err;
103 	int fd;
104 
105 	while (true) {
106 		err = bpf_prog_get_next_id(id, &id);
107 		if (err) {
108 			p_err("%s", strerror(errno));
109 			return -1;
110 		}
111 
112 		fd = bpf_prog_get_fd_by_id(id);
113 		if (fd < 0) {
114 			p_err("can't get prog by id (%u): %s",
115 			      id, strerror(errno));
116 			return -1;
117 		}
118 
119 		err = bpf_obj_get_info_by_fd(fd, &info, &len);
120 		if (err) {
121 			p_err("can't get prog info (%u): %s",
122 			      id, strerror(errno));
123 			close(fd);
124 			return -1;
125 		}
126 
127 		if (!memcmp(tag, info.tag, BPF_TAG_SIZE))
128 			return fd;
129 
130 		close(fd);
131 	}
132 }
133 
134 int prog_parse_fd(int *argc, char ***argv)
135 {
136 	int fd;
137 
138 	if (is_prefix(**argv, "id")) {
139 		unsigned int id;
140 		char *endptr;
141 
142 		NEXT_ARGP();
143 
144 		id = strtoul(**argv, &endptr, 0);
145 		if (*endptr) {
146 			p_err("can't parse %s as ID", **argv);
147 			return -1;
148 		}
149 		NEXT_ARGP();
150 
151 		fd = bpf_prog_get_fd_by_id(id);
152 		if (fd < 0)
153 			p_err("get by id (%u): %s", id, strerror(errno));
154 		return fd;
155 	} else if (is_prefix(**argv, "tag")) {
156 		unsigned char tag[BPF_TAG_SIZE];
157 
158 		NEXT_ARGP();
159 
160 		if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
161 			   tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
162 		    != BPF_TAG_SIZE) {
163 			p_err("can't parse tag");
164 			return -1;
165 		}
166 		NEXT_ARGP();
167 
168 		return prog_fd_by_tag(tag);
169 	} else if (is_prefix(**argv, "pinned")) {
170 		char *path;
171 
172 		NEXT_ARGP();
173 
174 		path = **argv;
175 		NEXT_ARGP();
176 
177 		return open_obj_pinned_any(path, BPF_OBJ_PROG);
178 	}
179 
180 	p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);
181 	return -1;
182 }
183 
184 static void show_prog_maps(int fd, u32 num_maps)
185 {
186 	struct bpf_prog_info info = {};
187 	__u32 len = sizeof(info);
188 	__u32 map_ids[num_maps];
189 	unsigned int i;
190 	int err;
191 
192 	info.nr_map_ids = num_maps;
193 	info.map_ids = ptr_to_u64(map_ids);
194 
195 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
196 	if (err || !info.nr_map_ids)
197 		return;
198 
199 	if (json_output) {
200 		jsonw_name(json_wtr, "map_ids");
201 		jsonw_start_array(json_wtr);
202 		for (i = 0; i < info.nr_map_ids; i++)
203 			jsonw_uint(json_wtr, map_ids[i]);
204 		jsonw_end_array(json_wtr);
205 	} else {
206 		printf("  map_ids ");
207 		for (i = 0; i < info.nr_map_ids; i++)
208 			printf("%u%s", map_ids[i],
209 			       i == info.nr_map_ids - 1 ? "" : ",");
210 	}
211 }
212 
213 static void print_prog_json(struct bpf_prog_info *info, int fd)
214 {
215 	char *memlock;
216 
217 	jsonw_start_object(json_wtr);
218 	jsonw_uint_field(json_wtr, "id", info->id);
219 	if (info->type < ARRAY_SIZE(prog_type_name))
220 		jsonw_string_field(json_wtr, "type",
221 				   prog_type_name[info->type]);
222 	else
223 		jsonw_uint_field(json_wtr, "type", info->type);
224 
225 	if (*info->name)
226 		jsonw_string_field(json_wtr, "name", info->name);
227 
228 	jsonw_name(json_wtr, "tag");
229 	jsonw_printf(json_wtr, "\"" BPF_TAG_FMT "\"",
230 		     info->tag[0], info->tag[1], info->tag[2], info->tag[3],
231 		     info->tag[4], info->tag[5], info->tag[6], info->tag[7]);
232 
233 	if (info->status & BPF_PROG_STATUS_DEV_BOUND) {
234 		jsonw_name(json_wtr, "dev");
235 		if (info->ifindex) {
236 			char name[IF_NAMESIZE];
237 
238 			if (!if_indextoname(info->ifindex, name))
239 				jsonw_printf(json_wtr, "\"ifindex:%d\"",
240 					     info->ifindex);
241 			else
242 				jsonw_printf(json_wtr, "\"%s\"", name);
243 		} else {
244 			jsonw_printf(json_wtr, "\"unknown\"");
245 		}
246 	}
247 
248 	if (info->load_time) {
249 		char buf[32];
250 
251 		print_boot_time(info->load_time, buf, sizeof(buf));
252 
253 		/* Piggy back on load_time, since 0 uid is a valid one */
254 		jsonw_string_field(json_wtr, "loaded_at", buf);
255 		jsonw_uint_field(json_wtr, "uid", info->created_by_uid);
256 	}
257 
258 	jsonw_uint_field(json_wtr, "bytes_xlated", info->xlated_prog_len);
259 
260 	if (info->jited_prog_len) {
261 		jsonw_bool_field(json_wtr, "jited", true);
262 		jsonw_uint_field(json_wtr, "bytes_jited", info->jited_prog_len);
263 	} else {
264 		jsonw_bool_field(json_wtr, "jited", false);
265 	}
266 
267 	memlock = get_fdinfo(fd, "memlock");
268 	if (memlock)
269 		jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
270 	free(memlock);
271 
272 	if (info->nr_map_ids)
273 		show_prog_maps(fd, info->nr_map_ids);
274 
275 	jsonw_end_object(json_wtr);
276 }
277 
278 static void print_prog_plain(struct bpf_prog_info *info, int fd)
279 {
280 	char *memlock;
281 
282 	printf("%u: ", info->id);
283 	if (info->type < ARRAY_SIZE(prog_type_name))
284 		printf("%s  ", prog_type_name[info->type]);
285 	else
286 		printf("type %u  ", info->type);
287 
288 	if (*info->name)
289 		printf("name %s  ", info->name);
290 
291 	printf("tag ");
292 	fprint_hex(stdout, info->tag, BPF_TAG_SIZE, "");
293 	printf(" ");
294 
295 	if (info->status & BPF_PROG_STATUS_DEV_BOUND) {
296 		printf("dev ");
297 		if (info->ifindex) {
298 			char name[IF_NAMESIZE];
299 
300 			if (!if_indextoname(info->ifindex, name))
301 				printf("ifindex:%d ", info->ifindex);
302 			else
303 				printf("%s ", name);
304 		} else {
305 			printf("unknown ");
306 		}
307 	}
308 	printf("\n");
309 
310 	if (info->load_time) {
311 		char buf[32];
312 
313 		print_boot_time(info->load_time, buf, sizeof(buf));
314 
315 		/* Piggy back on load_time, since 0 uid is a valid one */
316 		printf("\tloaded_at %s  uid %u\n", buf, info->created_by_uid);
317 	}
318 
319 	printf("\txlated %uB", info->xlated_prog_len);
320 
321 	if (info->jited_prog_len)
322 		printf("  jited %uB", info->jited_prog_len);
323 	else
324 		printf("  not jited");
325 
326 	memlock = get_fdinfo(fd, "memlock");
327 	if (memlock)
328 		printf("  memlock %sB", memlock);
329 	free(memlock);
330 
331 	if (info->nr_map_ids)
332 		show_prog_maps(fd, info->nr_map_ids);
333 
334 	printf("\n");
335 }
336 
337 static int show_prog(int fd)
338 {
339 	struct bpf_prog_info info = {};
340 	__u32 len = sizeof(info);
341 	int err;
342 
343 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
344 	if (err) {
345 		p_err("can't get prog info: %s", strerror(errno));
346 		return -1;
347 	}
348 
349 	if (json_output)
350 		print_prog_json(&info, fd);
351 	else
352 		print_prog_plain(&info, fd);
353 
354 	return 0;
355 }
356 
357 static int do_show(int argc, char **argv)
358 {
359 	__u32 id = 0;
360 	int err;
361 	int fd;
362 
363 	if (argc == 2) {
364 		fd = prog_parse_fd(&argc, &argv);
365 		if (fd < 0)
366 			return -1;
367 
368 		return show_prog(fd);
369 	}
370 
371 	if (argc)
372 		return BAD_ARG();
373 
374 	if (json_output)
375 		jsonw_start_array(json_wtr);
376 	while (true) {
377 		err = bpf_prog_get_next_id(id, &id);
378 		if (err) {
379 			if (errno == ENOENT) {
380 				err = 0;
381 				break;
382 			}
383 			p_err("can't get next program: %s%s", strerror(errno),
384 			      errno == EINVAL ? " -- kernel too old?" : "");
385 			err = -1;
386 			break;
387 		}
388 
389 		fd = bpf_prog_get_fd_by_id(id);
390 		if (fd < 0) {
391 			p_err("can't get prog by id (%u): %s",
392 			      id, strerror(errno));
393 			err = -1;
394 			break;
395 		}
396 
397 		err = show_prog(fd);
398 		close(fd);
399 		if (err)
400 			break;
401 	}
402 
403 	if (json_output)
404 		jsonw_end_array(json_wtr);
405 
406 	return err;
407 }
408 
409 static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...)
410 {
411 	va_list args;
412 
413 	va_start(args, fmt);
414 	vprintf(fmt, args);
415 	va_end(args);
416 }
417 
418 static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes)
419 {
420 	struct bpf_insn *insn = buf;
421 	bool double_insn = false;
422 	unsigned int i;
423 
424 	for (i = 0; i < len / sizeof(*insn); i++) {
425 		if (double_insn) {
426 			double_insn = false;
427 			continue;
428 		}
429 
430 		double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
431 
432 		printf("% 4d: ", i);
433 		print_bpf_insn(print_insn, NULL, insn + i, true);
434 
435 		if (opcodes) {
436 			printf("       ");
437 			fprint_hex(stdout, insn + i, 8, " ");
438 			if (double_insn && i < len - 1) {
439 				printf(" ");
440 				fprint_hex(stdout, insn + i + 1, 8, " ");
441 			}
442 			printf("\n");
443 		}
444 	}
445 }
446 
447 static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...)
448 {
449 	unsigned int l = strlen(fmt);
450 	char chomped_fmt[l];
451 	va_list args;
452 
453 	va_start(args, fmt);
454 	if (l > 0) {
455 		strncpy(chomped_fmt, fmt, l - 1);
456 		chomped_fmt[l - 1] = '\0';
457 	}
458 	jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
459 	va_end(args);
460 }
461 
462 static void dump_xlated_json(void *buf, unsigned int len, bool opcodes)
463 {
464 	struct bpf_insn *insn = buf;
465 	bool double_insn = false;
466 	unsigned int i;
467 
468 	jsonw_start_array(json_wtr);
469 	for (i = 0; i < len / sizeof(*insn); i++) {
470 		if (double_insn) {
471 			double_insn = false;
472 			continue;
473 		}
474 		double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
475 
476 		jsonw_start_object(json_wtr);
477 		jsonw_name(json_wtr, "disasm");
478 		print_bpf_insn(print_insn_json, NULL, insn + i, true);
479 
480 		if (opcodes) {
481 			jsonw_name(json_wtr, "opcodes");
482 			jsonw_start_object(json_wtr);
483 
484 			jsonw_name(json_wtr, "code");
485 			jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
486 
487 			jsonw_name(json_wtr, "src_reg");
488 			jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
489 
490 			jsonw_name(json_wtr, "dst_reg");
491 			jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
492 
493 			jsonw_name(json_wtr, "off");
494 			print_hex_data_json((uint8_t *)(&insn[i].off), 2);
495 
496 			jsonw_name(json_wtr, "imm");
497 			if (double_insn && i < len - 1)
498 				print_hex_data_json((uint8_t *)(&insn[i].imm),
499 						    12);
500 			else
501 				print_hex_data_json((uint8_t *)(&insn[i].imm),
502 						    4);
503 			jsonw_end_object(json_wtr);
504 		}
505 		jsonw_end_object(json_wtr);
506 	}
507 	jsonw_end_array(json_wtr);
508 }
509 
510 static int do_dump(int argc, char **argv)
511 {
512 	struct bpf_prog_info info = {};
513 	__u32 len = sizeof(info);
514 	unsigned int buf_size;
515 	char *filepath = NULL;
516 	bool opcodes = false;
517 	unsigned char *buf;
518 	__u32 *member_len;
519 	__u64 *member_ptr;
520 	ssize_t n;
521 	int err;
522 	int fd;
523 
524 	if (is_prefix(*argv, "jited")) {
525 		member_len = &info.jited_prog_len;
526 		member_ptr = &info.jited_prog_insns;
527 	} else if (is_prefix(*argv, "xlated")) {
528 		member_len = &info.xlated_prog_len;
529 		member_ptr = &info.xlated_prog_insns;
530 	} else {
531 		p_err("expected 'xlated' or 'jited', got: %s", *argv);
532 		return -1;
533 	}
534 	NEXT_ARG();
535 
536 	if (argc < 2)
537 		usage();
538 
539 	fd = prog_parse_fd(&argc, &argv);
540 	if (fd < 0)
541 		return -1;
542 
543 	if (is_prefix(*argv, "file")) {
544 		NEXT_ARG();
545 		if (!argc) {
546 			p_err("expected file path");
547 			return -1;
548 		}
549 
550 		filepath = *argv;
551 		NEXT_ARG();
552 	} else if (is_prefix(*argv, "opcodes")) {
553 		opcodes = true;
554 		NEXT_ARG();
555 	}
556 
557 	if (argc) {
558 		usage();
559 		return -1;
560 	}
561 
562 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
563 	if (err) {
564 		p_err("can't get prog info: %s", strerror(errno));
565 		return -1;
566 	}
567 
568 	if (!*member_len) {
569 		p_info("no instructions returned");
570 		close(fd);
571 		return 0;
572 	}
573 
574 	buf_size = *member_len;
575 
576 	buf = malloc(buf_size);
577 	if (!buf) {
578 		p_err("mem alloc failed");
579 		close(fd);
580 		return -1;
581 	}
582 
583 	memset(&info, 0, sizeof(info));
584 
585 	*member_ptr = ptr_to_u64(buf);
586 	*member_len = buf_size;
587 
588 	err = bpf_obj_get_info_by_fd(fd, &info, &len);
589 	close(fd);
590 	if (err) {
591 		p_err("can't get prog info: %s", strerror(errno));
592 		goto err_free;
593 	}
594 
595 	if (*member_len > buf_size) {
596 		p_err("too many instructions returned");
597 		goto err_free;
598 	}
599 
600 	if (filepath) {
601 		fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
602 		if (fd < 0) {
603 			p_err("can't open file %s: %s", filepath,
604 			      strerror(errno));
605 			goto err_free;
606 		}
607 
608 		n = write(fd, buf, *member_len);
609 		close(fd);
610 		if (n != *member_len) {
611 			p_err("error writing output file: %s",
612 			      n < 0 ? strerror(errno) : "short write");
613 			goto err_free;
614 		}
615 	} else {
616 		if (member_len == &info.jited_prog_len)
617 			disasm_print_insn(buf, *member_len, opcodes);
618 		else
619 			if (json_output)
620 				dump_xlated_json(buf, *member_len, opcodes);
621 			else
622 				dump_xlated_plain(buf, *member_len, opcodes);
623 	}
624 
625 	free(buf);
626 
627 	return 0;
628 
629 err_free:
630 	free(buf);
631 	return -1;
632 }
633 
634 static int do_pin(int argc, char **argv)
635 {
636 	int err;
637 
638 	err = do_pin_any(argc, argv, bpf_prog_get_fd_by_id);
639 	if (!err && json_output)
640 		jsonw_null(json_wtr);
641 	return err;
642 }
643 
644 static int do_help(int argc, char **argv)
645 {
646 	if (json_output) {
647 		jsonw_null(json_wtr);
648 		return 0;
649 	}
650 
651 	fprintf(stderr,
652 		"Usage: %s %s show [PROG]\n"
653 		"       %s %s dump xlated PROG [{ file FILE | opcodes }]\n"
654 		"       %s %s dump jited  PROG [{ file FILE | opcodes }]\n"
655 		"       %s %s pin   PROG FILE\n"
656 		"       %s %s help\n"
657 		"\n"
658 		"       " HELP_SPEC_PROGRAM "\n"
659 		"       " HELP_SPEC_OPTIONS "\n"
660 		"",
661 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
662 		bin_name, argv[-2], bin_name, argv[-2]);
663 
664 	return 0;
665 }
666 
667 static const struct cmd cmds[] = {
668 	{ "show",	do_show },
669 	{ "help",	do_help },
670 	{ "dump",	do_dump },
671 	{ "pin",	do_pin },
672 	{ 0 }
673 };
674 
675 int do_prog(int argc, char **argv)
676 {
677 	return cmd_select(cmds, argc, argv, do_help);
678 }
679