xref: /openbmc/linux/tools/bpf/bpftool/main.c (revision 36de991e)
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/btf.h>
14 #include <bpf/hashmap.h>
15 #include <bpf/libbpf.h>
16 
17 #include "main.h"
18 
19 #define BATCH_LINE_LEN_MAX 65536
20 #define BATCH_ARG_NB_MAX 4096
21 
22 const char *bin_name;
23 static int last_argc;
24 static char **last_argv;
25 static int (*last_do_help)(int argc, char **argv);
26 json_writer_t *json_wtr;
27 bool pretty_output;
28 bool json_output;
29 bool show_pinned;
30 bool block_mount;
31 bool verifier_logs;
32 bool relaxed_maps;
33 bool use_loader;
34 struct btf *base_btf;
35 struct hashmap *refs_table;
36 
37 static void __noreturn clean_and_exit(int i)
38 {
39 	if (json_output)
40 		jsonw_destroy(&json_wtr);
41 
42 	exit(i);
43 }
44 
45 void usage(void)
46 {
47 	last_do_help(last_argc - 1, last_argv + 1);
48 
49 	clean_and_exit(-1);
50 }
51 
52 static int do_help(int argc, char **argv)
53 {
54 	if (json_output) {
55 		jsonw_null(json_wtr);
56 		return 0;
57 	}
58 
59 	fprintf(stderr,
60 		"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
61 		"       %s batch file FILE\n"
62 		"       %s version\n"
63 		"\n"
64 		"       OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter }\n"
65 		"       " HELP_SPEC_OPTIONS " |\n"
66 		"                    {-V|--version} }\n"
67 		"",
68 		bin_name, bin_name, bin_name);
69 
70 	return 0;
71 }
72 
73 static int do_version(int argc, char **argv)
74 {
75 #ifdef HAVE_LIBBFD_SUPPORT
76 	const bool has_libbfd = true;
77 #else
78 	const bool has_libbfd = false;
79 #endif
80 #ifdef BPFTOOL_WITHOUT_SKELETONS
81 	const bool has_skeletons = false;
82 #else
83 	const bool has_skeletons = true;
84 #endif
85 
86 	if (json_output) {
87 		jsonw_start_object(json_wtr);	/* root object */
88 
89 		jsonw_name(json_wtr, "version");
90 		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
91 
92 		jsonw_name(json_wtr, "features");
93 		jsonw_start_object(json_wtr);	/* features */
94 		jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
95 		jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
96 		jsonw_end_object(json_wtr);	/* features */
97 
98 		jsonw_end_object(json_wtr);	/* root object */
99 	} else {
100 		unsigned int nb_features = 0;
101 
102 		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
103 		printf("features:");
104 		if (has_libbfd) {
105 			printf(" libbfd");
106 			nb_features++;
107 		}
108 		if (has_skeletons)
109 			printf("%s skeletons", nb_features++ ? "," : "");
110 		printf("\n");
111 	}
112 	return 0;
113 }
114 
115 int cmd_select(const struct cmd *cmds, int argc, char **argv,
116 	       int (*help)(int argc, char **argv))
117 {
118 	unsigned int i;
119 
120 	last_argc = argc;
121 	last_argv = argv;
122 	last_do_help = help;
123 
124 	if (argc < 1 && cmds[0].func)
125 		return cmds[0].func(argc, argv);
126 
127 	for (i = 0; cmds[i].cmd; i++) {
128 		if (is_prefix(*argv, cmds[i].cmd)) {
129 			if (!cmds[i].func) {
130 				p_err("command '%s' is not supported in bootstrap mode",
131 				      cmds[i].cmd);
132 				return -1;
133 			}
134 			return cmds[i].func(argc - 1, argv + 1);
135 		}
136 	}
137 
138 	help(argc - 1, argv + 1);
139 
140 	return -1;
141 }
142 
143 bool is_prefix(const char *pfx, const char *str)
144 {
145 	if (!pfx)
146 		return false;
147 	if (strlen(str) < strlen(pfx))
148 		return false;
149 
150 	return !memcmp(str, pfx, strlen(pfx));
151 }
152 
153 /* Last argument MUST be NULL pointer */
154 int detect_common_prefix(const char *arg, ...)
155 {
156 	unsigned int count = 0;
157 	const char *ref;
158 	char msg[256];
159 	va_list ap;
160 
161 	snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
162 	va_start(ap, arg);
163 	while ((ref = va_arg(ap, const char *))) {
164 		if (!is_prefix(arg, ref))
165 			continue;
166 		count++;
167 		if (count > 1)
168 			strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
169 		strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
170 	}
171 	va_end(ap);
172 	strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
173 
174 	if (count >= 2) {
175 		p_err("%s", msg);
176 		return -1;
177 	}
178 
179 	return 0;
180 }
181 
182 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
183 {
184 	unsigned char *data = arg;
185 	unsigned int i;
186 
187 	for (i = 0; i < n; i++) {
188 		const char *pfx = "";
189 
190 		if (!i)
191 			/* nothing */;
192 		else if (!(i % 16))
193 			fprintf(f, "\n");
194 		else if (!(i % 8))
195 			fprintf(f, "  ");
196 		else
197 			pfx = sep;
198 
199 		fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
200 	}
201 }
202 
203 /* Split command line into argument vector. */
204 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
205 {
206 	static const char ws[] = " \t\r\n";
207 	char *cp = line;
208 	int n_argc = 0;
209 
210 	while (*cp) {
211 		/* Skip leading whitespace. */
212 		cp += strspn(cp, ws);
213 
214 		if (*cp == '\0')
215 			break;
216 
217 		if (n_argc >= (maxargs - 1)) {
218 			p_err("too many arguments to command %d", cmd_nb);
219 			return -1;
220 		}
221 
222 		/* Word begins with quote. */
223 		if (*cp == '\'' || *cp == '"') {
224 			char quote = *cp++;
225 
226 			n_argv[n_argc++] = cp;
227 			/* Find ending quote. */
228 			cp = strchr(cp, quote);
229 			if (!cp) {
230 				p_err("unterminated quoted string in command %d",
231 				      cmd_nb);
232 				return -1;
233 			}
234 		} else {
235 			n_argv[n_argc++] = cp;
236 
237 			/* Find end of word. */
238 			cp += strcspn(cp, ws);
239 			if (*cp == '\0')
240 				break;
241 		}
242 
243 		/* Separate words. */
244 		*cp++ = 0;
245 	}
246 	n_argv[n_argc] = NULL;
247 
248 	return n_argc;
249 }
250 
251 static int do_batch(int argc, char **argv);
252 
253 static const struct cmd cmds[] = {
254 	{ "help",	do_help },
255 	{ "batch",	do_batch },
256 	{ "prog",	do_prog },
257 	{ "map",	do_map },
258 	{ "link",	do_link },
259 	{ "cgroup",	do_cgroup },
260 	{ "perf",	do_perf },
261 	{ "net",	do_net },
262 	{ "feature",	do_feature },
263 	{ "btf",	do_btf },
264 	{ "gen",	do_gen },
265 	{ "struct_ops",	do_struct_ops },
266 	{ "iter",	do_iter },
267 	{ "version",	do_version },
268 	{ 0 }
269 };
270 
271 static int do_batch(int argc, char **argv)
272 {
273 	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
274 	char *n_argv[BATCH_ARG_NB_MAX];
275 	unsigned int lines = 0;
276 	int n_argc;
277 	FILE *fp;
278 	char *cp;
279 	int err = 0;
280 	int i;
281 
282 	if (argc < 2) {
283 		p_err("too few parameters for batch");
284 		return -1;
285 	} else if (!is_prefix(*argv, "file")) {
286 		p_err("expected 'file', got: %s", *argv);
287 		return -1;
288 	} else if (argc > 2) {
289 		p_err("too many parameters for batch");
290 		return -1;
291 	}
292 	NEXT_ARG();
293 
294 	if (!strcmp(*argv, "-"))
295 		fp = stdin;
296 	else
297 		fp = fopen(*argv, "r");
298 	if (!fp) {
299 		p_err("Can't open file (%s): %s", *argv, strerror(errno));
300 		return -1;
301 	}
302 
303 	if (json_output)
304 		jsonw_start_array(json_wtr);
305 	while (fgets(buf, sizeof(buf), fp)) {
306 		cp = strchr(buf, '#');
307 		if (cp)
308 			*cp = '\0';
309 
310 		if (strlen(buf) == sizeof(buf) - 1) {
311 			errno = E2BIG;
312 			break;
313 		}
314 
315 		/* Append continuation lines if any (coming after a line ending
316 		 * with '\' in the batch file).
317 		 */
318 		while ((cp = strstr(buf, "\\\n")) != NULL) {
319 			if (!fgets(contline, sizeof(contline), fp) ||
320 			    strlen(contline) == 0) {
321 				p_err("missing continuation line on command %d",
322 				      lines);
323 				err = -1;
324 				goto err_close;
325 			}
326 
327 			cp = strchr(contline, '#');
328 			if (cp)
329 				*cp = '\0';
330 
331 			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
332 				p_err("command %d is too long", lines);
333 				err = -1;
334 				goto err_close;
335 			}
336 			buf[strlen(buf) - 2] = '\0';
337 			strcat(buf, contline);
338 		}
339 
340 		n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
341 		if (!n_argc)
342 			continue;
343 		if (n_argc < 0) {
344 			err = n_argc;
345 			goto err_close;
346 		}
347 
348 		if (json_output) {
349 			jsonw_start_object(json_wtr);
350 			jsonw_name(json_wtr, "command");
351 			jsonw_start_array(json_wtr);
352 			for (i = 0; i < n_argc; i++)
353 				jsonw_string(json_wtr, n_argv[i]);
354 			jsonw_end_array(json_wtr);
355 			jsonw_name(json_wtr, "output");
356 		}
357 
358 		err = cmd_select(cmds, n_argc, n_argv, do_help);
359 
360 		if (json_output)
361 			jsonw_end_object(json_wtr);
362 
363 		if (err)
364 			goto err_close;
365 
366 		lines++;
367 	}
368 
369 	if (errno && errno != ENOENT) {
370 		p_err("reading batch file failed: %s", strerror(errno));
371 		err = -1;
372 	} else {
373 		if (!json_output)
374 			printf("processed %d commands\n", lines);
375 	}
376 err_close:
377 	if (fp != stdin)
378 		fclose(fp);
379 
380 	if (json_output)
381 		jsonw_end_array(json_wtr);
382 
383 	return err;
384 }
385 
386 int main(int argc, char **argv)
387 {
388 	static const struct option options[] = {
389 		{ "json",	no_argument,	NULL,	'j' },
390 		{ "help",	no_argument,	NULL,	'h' },
391 		{ "pretty",	no_argument,	NULL,	'p' },
392 		{ "version",	no_argument,	NULL,	'V' },
393 		{ "bpffs",	no_argument,	NULL,	'f' },
394 		{ "mapcompat",	no_argument,	NULL,	'm' },
395 		{ "nomount",	no_argument,	NULL,	'n' },
396 		{ "debug",	no_argument,	NULL,	'd' },
397 		{ "use-loader",	no_argument,	NULL,	'L' },
398 		{ "base-btf",	required_argument, NULL, 'B' },
399 		{ 0 }
400 	};
401 	int opt, ret;
402 
403 	last_do_help = do_help;
404 	pretty_output = false;
405 	json_output = false;
406 	show_pinned = false;
407 	block_mount = false;
408 	bin_name = argv[0];
409 
410 	opterr = 0;
411 	while ((opt = getopt_long(argc, argv, "VhpjfLmndB:",
412 				  options, NULL)) >= 0) {
413 		switch (opt) {
414 		case 'V':
415 			return do_version(argc, argv);
416 		case 'h':
417 			return do_help(argc, argv);
418 		case 'p':
419 			pretty_output = true;
420 			/* fall through */
421 		case 'j':
422 			if (!json_output) {
423 				json_wtr = jsonw_new(stdout);
424 				if (!json_wtr) {
425 					p_err("failed to create JSON writer");
426 					return -1;
427 				}
428 				json_output = true;
429 			}
430 			jsonw_pretty(json_wtr, pretty_output);
431 			break;
432 		case 'f':
433 			show_pinned = true;
434 			break;
435 		case 'm':
436 			relaxed_maps = true;
437 			break;
438 		case 'n':
439 			block_mount = true;
440 			break;
441 		case 'd':
442 			libbpf_set_print(print_all_levels);
443 			verifier_logs = true;
444 			break;
445 		case 'B':
446 			base_btf = btf__parse(optarg, NULL);
447 			if (libbpf_get_error(base_btf)) {
448 				p_err("failed to parse base BTF at '%s': %ld\n",
449 				      optarg, libbpf_get_error(base_btf));
450 				base_btf = NULL;
451 				return -1;
452 			}
453 			break;
454 		case 'L':
455 			use_loader = true;
456 			break;
457 		default:
458 			p_err("unrecognized option '%s'", argv[optind - 1]);
459 			if (json_output)
460 				clean_and_exit(-1);
461 			else
462 				usage();
463 		}
464 	}
465 
466 	argc -= optind;
467 	argv += optind;
468 	if (argc < 0)
469 		usage();
470 
471 	ret = cmd_select(cmds, argc, argv, do_help);
472 
473 	if (json_output)
474 		jsonw_destroy(&json_wtr);
475 
476 	btf__free(base_btf);
477 
478 	return ret;
479 }
480