xref: /openbmc/linux/tools/bpf/bpftool/main.c (revision e481ff3f)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
3 
4 #include <ctype.h>
5 #include <errno.h>
6 #include <getopt.h>
7 #include <linux/bpf.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <string.h>
11 
12 #include <bpf/bpf.h>
13 #include <bpf/libbpf.h>
14 #include <bpf/btf.h>
15 
16 #include "main.h"
17 
18 #define BATCH_LINE_LEN_MAX 65536
19 #define BATCH_ARG_NB_MAX 4096
20 
21 const char *bin_name;
22 static int last_argc;
23 static char **last_argv;
24 static int (*last_do_help)(int argc, char **argv);
25 json_writer_t *json_wtr;
26 bool pretty_output;
27 bool json_output;
28 bool show_pinned;
29 bool block_mount;
30 bool verifier_logs;
31 bool relaxed_maps;
32 bool use_loader;
33 struct btf *base_btf;
34 struct pinned_obj_table prog_table;
35 struct pinned_obj_table map_table;
36 struct pinned_obj_table link_table;
37 struct obj_refs_table refs_table;
38 
39 static void __noreturn clean_and_exit(int i)
40 {
41 	if (json_output)
42 		jsonw_destroy(&json_wtr);
43 
44 	exit(i);
45 }
46 
47 void usage(void)
48 {
49 	last_do_help(last_argc - 1, last_argv + 1);
50 
51 	clean_and_exit(-1);
52 }
53 
54 static int do_help(int argc, char **argv)
55 {
56 	if (json_output) {
57 		jsonw_null(json_wtr);
58 		return 0;
59 	}
60 
61 	fprintf(stderr,
62 		"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
63 		"       %s batch file FILE\n"
64 		"       %s version\n"
65 		"\n"
66 		"       OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter }\n"
67 		"       " HELP_SPEC_OPTIONS "\n"
68 		"",
69 		bin_name, bin_name, bin_name);
70 
71 	return 0;
72 }
73 
74 static int do_version(int argc, char **argv)
75 {
76 #ifdef HAVE_LIBBFD_SUPPORT
77 	const bool has_libbfd = true;
78 #else
79 	const bool has_libbfd = false;
80 #endif
81 #ifdef BPFTOOL_WITHOUT_SKELETONS
82 	const bool has_skeletons = false;
83 #else
84 	const bool has_skeletons = true;
85 #endif
86 
87 	if (json_output) {
88 		jsonw_start_object(json_wtr);	/* root object */
89 
90 		jsonw_name(json_wtr, "version");
91 		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
92 
93 		jsonw_name(json_wtr, "features");
94 		jsonw_start_object(json_wtr);	/* features */
95 		jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
96 		jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
97 		jsonw_end_object(json_wtr);	/* features */
98 
99 		jsonw_end_object(json_wtr);	/* root object */
100 	} else {
101 		unsigned int nb_features = 0;
102 
103 		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
104 		printf("features:");
105 		if (has_libbfd) {
106 			printf(" libbfd");
107 			nb_features++;
108 		}
109 		if (has_skeletons)
110 			printf("%s skeletons", nb_features++ ? "," : "");
111 		printf("\n");
112 	}
113 	return 0;
114 }
115 
116 int cmd_select(const struct cmd *cmds, int argc, char **argv,
117 	       int (*help)(int argc, char **argv))
118 {
119 	unsigned int i;
120 
121 	last_argc = argc;
122 	last_argv = argv;
123 	last_do_help = help;
124 
125 	if (argc < 1 && cmds[0].func)
126 		return cmds[0].func(argc, argv);
127 
128 	for (i = 0; cmds[i].cmd; i++) {
129 		if (is_prefix(*argv, cmds[i].cmd)) {
130 			if (!cmds[i].func) {
131 				p_err("command '%s' is not supported in bootstrap mode",
132 				      cmds[i].cmd);
133 				return -1;
134 			}
135 			return cmds[i].func(argc - 1, argv + 1);
136 		}
137 	}
138 
139 	help(argc - 1, argv + 1);
140 
141 	return -1;
142 }
143 
144 bool is_prefix(const char *pfx, const char *str)
145 {
146 	if (!pfx)
147 		return false;
148 	if (strlen(str) < strlen(pfx))
149 		return false;
150 
151 	return !memcmp(str, pfx, strlen(pfx));
152 }
153 
154 /* Last argument MUST be NULL pointer */
155 int detect_common_prefix(const char *arg, ...)
156 {
157 	unsigned int count = 0;
158 	const char *ref;
159 	char msg[256];
160 	va_list ap;
161 
162 	snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
163 	va_start(ap, arg);
164 	while ((ref = va_arg(ap, const char *))) {
165 		if (!is_prefix(arg, ref))
166 			continue;
167 		count++;
168 		if (count > 1)
169 			strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
170 		strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
171 	}
172 	va_end(ap);
173 	strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
174 
175 	if (count >= 2) {
176 		p_err("%s", msg);
177 		return -1;
178 	}
179 
180 	return 0;
181 }
182 
183 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
184 {
185 	unsigned char *data = arg;
186 	unsigned int i;
187 
188 	for (i = 0; i < n; i++) {
189 		const char *pfx = "";
190 
191 		if (!i)
192 			/* nothing */;
193 		else if (!(i % 16))
194 			fprintf(f, "\n");
195 		else if (!(i % 8))
196 			fprintf(f, "  ");
197 		else
198 			pfx = sep;
199 
200 		fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
201 	}
202 }
203 
204 /* Split command line into argument vector. */
205 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
206 {
207 	static const char ws[] = " \t\r\n";
208 	char *cp = line;
209 	int n_argc = 0;
210 
211 	while (*cp) {
212 		/* Skip leading whitespace. */
213 		cp += strspn(cp, ws);
214 
215 		if (*cp == '\0')
216 			break;
217 
218 		if (n_argc >= (maxargs - 1)) {
219 			p_err("too many arguments to command %d", cmd_nb);
220 			return -1;
221 		}
222 
223 		/* Word begins with quote. */
224 		if (*cp == '\'' || *cp == '"') {
225 			char quote = *cp++;
226 
227 			n_argv[n_argc++] = cp;
228 			/* Find ending quote. */
229 			cp = strchr(cp, quote);
230 			if (!cp) {
231 				p_err("unterminated quoted string in command %d",
232 				      cmd_nb);
233 				return -1;
234 			}
235 		} else {
236 			n_argv[n_argc++] = cp;
237 
238 			/* Find end of word. */
239 			cp += strcspn(cp, ws);
240 			if (*cp == '\0')
241 				break;
242 		}
243 
244 		/* Separate words. */
245 		*cp++ = 0;
246 	}
247 	n_argv[n_argc] = NULL;
248 
249 	return n_argc;
250 }
251 
252 static int do_batch(int argc, char **argv);
253 
254 static const struct cmd cmds[] = {
255 	{ "help",	do_help },
256 	{ "batch",	do_batch },
257 	{ "prog",	do_prog },
258 	{ "map",	do_map },
259 	{ "link",	do_link },
260 	{ "cgroup",	do_cgroup },
261 	{ "perf",	do_perf },
262 	{ "net",	do_net },
263 	{ "feature",	do_feature },
264 	{ "btf",	do_btf },
265 	{ "gen",	do_gen },
266 	{ "struct_ops",	do_struct_ops },
267 	{ "iter",	do_iter },
268 	{ "version",	do_version },
269 	{ 0 }
270 };
271 
272 static int do_batch(int argc, char **argv)
273 {
274 	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
275 	char *n_argv[BATCH_ARG_NB_MAX];
276 	unsigned int lines = 0;
277 	int n_argc;
278 	FILE *fp;
279 	char *cp;
280 	int err = 0;
281 	int i;
282 
283 	if (argc < 2) {
284 		p_err("too few parameters for batch");
285 		return -1;
286 	} else if (!is_prefix(*argv, "file")) {
287 		p_err("expected 'file', got: %s", *argv);
288 		return -1;
289 	} else if (argc > 2) {
290 		p_err("too many parameters for batch");
291 		return -1;
292 	}
293 	NEXT_ARG();
294 
295 	if (!strcmp(*argv, "-"))
296 		fp = stdin;
297 	else
298 		fp = fopen(*argv, "r");
299 	if (!fp) {
300 		p_err("Can't open file (%s): %s", *argv, strerror(errno));
301 		return -1;
302 	}
303 
304 	if (json_output)
305 		jsonw_start_array(json_wtr);
306 	while (fgets(buf, sizeof(buf), fp)) {
307 		cp = strchr(buf, '#');
308 		if (cp)
309 			*cp = '\0';
310 
311 		if (strlen(buf) == sizeof(buf) - 1) {
312 			errno = E2BIG;
313 			break;
314 		}
315 
316 		/* Append continuation lines if any (coming after a line ending
317 		 * with '\' in the batch file).
318 		 */
319 		while ((cp = strstr(buf, "\\\n")) != NULL) {
320 			if (!fgets(contline, sizeof(contline), fp) ||
321 			    strlen(contline) == 0) {
322 				p_err("missing continuation line on command %d",
323 				      lines);
324 				err = -1;
325 				goto err_close;
326 			}
327 
328 			cp = strchr(contline, '#');
329 			if (cp)
330 				*cp = '\0';
331 
332 			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
333 				p_err("command %d is too long", lines);
334 				err = -1;
335 				goto err_close;
336 			}
337 			buf[strlen(buf) - 2] = '\0';
338 			strcat(buf, contline);
339 		}
340 
341 		n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
342 		if (!n_argc)
343 			continue;
344 		if (n_argc < 0) {
345 			err = n_argc;
346 			goto err_close;
347 		}
348 
349 		if (json_output) {
350 			jsonw_start_object(json_wtr);
351 			jsonw_name(json_wtr, "command");
352 			jsonw_start_array(json_wtr);
353 			for (i = 0; i < n_argc; i++)
354 				jsonw_string(json_wtr, n_argv[i]);
355 			jsonw_end_array(json_wtr);
356 			jsonw_name(json_wtr, "output");
357 		}
358 
359 		err = cmd_select(cmds, n_argc, n_argv, do_help);
360 
361 		if (json_output)
362 			jsonw_end_object(json_wtr);
363 
364 		if (err)
365 			goto err_close;
366 
367 		lines++;
368 	}
369 
370 	if (errno && errno != ENOENT) {
371 		p_err("reading batch file failed: %s", strerror(errno));
372 		err = -1;
373 	} else {
374 		if (!json_output)
375 			printf("processed %d commands\n", lines);
376 	}
377 err_close:
378 	if (fp != stdin)
379 		fclose(fp);
380 
381 	if (json_output)
382 		jsonw_end_array(json_wtr);
383 
384 	return err;
385 }
386 
387 int main(int argc, char **argv)
388 {
389 	static const struct option options[] = {
390 		{ "json",	no_argument,	NULL,	'j' },
391 		{ "help",	no_argument,	NULL,	'h' },
392 		{ "pretty",	no_argument,	NULL,	'p' },
393 		{ "version",	no_argument,	NULL,	'V' },
394 		{ "bpffs",	no_argument,	NULL,	'f' },
395 		{ "mapcompat",	no_argument,	NULL,	'm' },
396 		{ "nomount",	no_argument,	NULL,	'n' },
397 		{ "debug",	no_argument,	NULL,	'd' },
398 		{ "use-loader",	no_argument,	NULL,	'L' },
399 		{ "base-btf",	required_argument, NULL, 'B' },
400 		{ 0 }
401 	};
402 	int opt, ret;
403 
404 	last_do_help = do_help;
405 	pretty_output = false;
406 	json_output = false;
407 	show_pinned = false;
408 	block_mount = false;
409 	bin_name = argv[0];
410 
411 	hash_init(prog_table.table);
412 	hash_init(map_table.table);
413 	hash_init(link_table.table);
414 
415 	opterr = 0;
416 	while ((opt = getopt_long(argc, argv, "VhpjfLmndB:",
417 				  options, NULL)) >= 0) {
418 		switch (opt) {
419 		case 'V':
420 			return do_version(argc, argv);
421 		case 'h':
422 			return do_help(argc, argv);
423 		case 'p':
424 			pretty_output = true;
425 			/* fall through */
426 		case 'j':
427 			if (!json_output) {
428 				json_wtr = jsonw_new(stdout);
429 				if (!json_wtr) {
430 					p_err("failed to create JSON writer");
431 					return -1;
432 				}
433 				json_output = true;
434 			}
435 			jsonw_pretty(json_wtr, pretty_output);
436 			break;
437 		case 'f':
438 			show_pinned = true;
439 			break;
440 		case 'm':
441 			relaxed_maps = true;
442 			break;
443 		case 'n':
444 			block_mount = true;
445 			break;
446 		case 'd':
447 			libbpf_set_print(print_all_levels);
448 			verifier_logs = true;
449 			break;
450 		case 'B':
451 			base_btf = btf__parse(optarg, NULL);
452 			if (libbpf_get_error(base_btf)) {
453 				p_err("failed to parse base BTF at '%s': %ld\n",
454 				      optarg, libbpf_get_error(base_btf));
455 				base_btf = NULL;
456 				return -1;
457 			}
458 			break;
459 		case 'L':
460 			use_loader = true;
461 			break;
462 		default:
463 			p_err("unrecognized option '%s'", argv[optind - 1]);
464 			if (json_output)
465 				clean_and_exit(-1);
466 			else
467 				usage();
468 		}
469 	}
470 
471 	argc -= optind;
472 	argv += optind;
473 	if (argc < 0)
474 		usage();
475 
476 	ret = cmd_select(cmds, argc, argv, do_help);
477 
478 	if (json_output)
479 		jsonw_destroy(&json_wtr);
480 
481 	if (show_pinned) {
482 		delete_pinned_obj_table(&prog_table);
483 		delete_pinned_obj_table(&map_table);
484 		delete_pinned_obj_table(&link_table);
485 	}
486 	btf__free(base_btf);
487 
488 	return ret;
489 }
490