xref: /openbmc/linux/tools/bpf/bpftool/main.c (revision 62975d27)
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 
15 #include "main.h"
16 
17 #define BATCH_LINE_LEN_MAX 65536
18 #define BATCH_ARG_NB_MAX 4096
19 
20 const char *bin_name;
21 static int last_argc;
22 static char **last_argv;
23 static int (*last_do_help)(int argc, char **argv);
24 json_writer_t *json_wtr;
25 bool pretty_output;
26 bool json_output;
27 bool show_pinned;
28 bool block_mount;
29 bool verifier_logs;
30 bool relaxed_maps;
31 struct pinned_obj_table prog_table;
32 struct pinned_obj_table map_table;
33 struct pinned_obj_table link_table;
34 
35 static void __noreturn clean_and_exit(int i)
36 {
37 	if (json_output)
38 		jsonw_destroy(&json_wtr);
39 
40 	exit(i);
41 }
42 
43 void usage(void)
44 {
45 	last_do_help(last_argc - 1, last_argv + 1);
46 
47 	clean_and_exit(-1);
48 }
49 
50 static int do_help(int argc, char **argv)
51 {
52 	if (json_output) {
53 		jsonw_null(json_wtr);
54 		return 0;
55 	}
56 
57 	fprintf(stderr,
58 		"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
59 		"       %s batch file FILE\n"
60 		"       %s version\n"
61 		"\n"
62 		"       OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter }\n"
63 		"       " HELP_SPEC_OPTIONS "\n"
64 		"",
65 		bin_name, bin_name, bin_name);
66 
67 	return 0;
68 }
69 
70 static int do_version(int argc, char **argv)
71 {
72 	if (json_output) {
73 		jsonw_start_object(json_wtr);
74 		jsonw_name(json_wtr, "version");
75 		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
76 		jsonw_end_object(json_wtr);
77 	} else {
78 		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
79 	}
80 	return 0;
81 }
82 
83 int cmd_select(const struct cmd *cmds, int argc, char **argv,
84 	       int (*help)(int argc, char **argv))
85 {
86 	unsigned int i;
87 
88 	last_argc = argc;
89 	last_argv = argv;
90 	last_do_help = help;
91 
92 	if (argc < 1 && cmds[0].func)
93 		return cmds[0].func(argc, argv);
94 
95 	for (i = 0; cmds[i].func; i++)
96 		if (is_prefix(*argv, cmds[i].cmd))
97 			return cmds[i].func(argc - 1, argv + 1);
98 
99 	help(argc - 1, argv + 1);
100 
101 	return -1;
102 }
103 
104 bool is_prefix(const char *pfx, const char *str)
105 {
106 	if (!pfx)
107 		return false;
108 	if (strlen(str) < strlen(pfx))
109 		return false;
110 
111 	return !memcmp(str, pfx, strlen(pfx));
112 }
113 
114 /* Last argument MUST be NULL pointer */
115 int detect_common_prefix(const char *arg, ...)
116 {
117 	unsigned int count = 0;
118 	const char *ref;
119 	char msg[256];
120 	va_list ap;
121 
122 	snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
123 	va_start(ap, arg);
124 	while ((ref = va_arg(ap, const char *))) {
125 		if (!is_prefix(arg, ref))
126 			continue;
127 		count++;
128 		if (count > 1)
129 			strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
130 		strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
131 	}
132 	va_end(ap);
133 	strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
134 
135 	if (count >= 2) {
136 		p_err("%s", msg);
137 		return -1;
138 	}
139 
140 	return 0;
141 }
142 
143 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
144 {
145 	unsigned char *data = arg;
146 	unsigned int i;
147 
148 	for (i = 0; i < n; i++) {
149 		const char *pfx = "";
150 
151 		if (!i)
152 			/* nothing */;
153 		else if (!(i % 16))
154 			fprintf(f, "\n");
155 		else if (!(i % 8))
156 			fprintf(f, "  ");
157 		else
158 			pfx = sep;
159 
160 		fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
161 	}
162 }
163 
164 /* Split command line into argument vector. */
165 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
166 {
167 	static const char ws[] = " \t\r\n";
168 	char *cp = line;
169 	int n_argc = 0;
170 
171 	while (*cp) {
172 		/* Skip leading whitespace. */
173 		cp += strspn(cp, ws);
174 
175 		if (*cp == '\0')
176 			break;
177 
178 		if (n_argc >= (maxargs - 1)) {
179 			p_err("too many arguments to command %d", cmd_nb);
180 			return -1;
181 		}
182 
183 		/* Word begins with quote. */
184 		if (*cp == '\'' || *cp == '"') {
185 			char quote = *cp++;
186 
187 			n_argv[n_argc++] = cp;
188 			/* Find ending quote. */
189 			cp = strchr(cp, quote);
190 			if (!cp) {
191 				p_err("unterminated quoted string in command %d",
192 				      cmd_nb);
193 				return -1;
194 			}
195 		} else {
196 			n_argv[n_argc++] = cp;
197 
198 			/* Find end of word. */
199 			cp += strcspn(cp, ws);
200 			if (*cp == '\0')
201 				break;
202 		}
203 
204 		/* Separate words. */
205 		*cp++ = 0;
206 	}
207 	n_argv[n_argc] = NULL;
208 
209 	return n_argc;
210 }
211 
212 static int do_batch(int argc, char **argv);
213 
214 static const struct cmd cmds[] = {
215 	{ "help",	do_help },
216 	{ "batch",	do_batch },
217 	{ "prog",	do_prog },
218 	{ "map",	do_map },
219 	{ "link",	do_link },
220 	{ "cgroup",	do_cgroup },
221 	{ "perf",	do_perf },
222 	{ "net",	do_net },
223 	{ "feature",	do_feature },
224 	{ "btf",	do_btf },
225 	{ "gen",	do_gen },
226 	{ "struct_ops",	do_struct_ops },
227 	{ "iter",	do_iter },
228 	{ "version",	do_version },
229 	{ 0 }
230 };
231 
232 static int do_batch(int argc, char **argv)
233 {
234 	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
235 	char *n_argv[BATCH_ARG_NB_MAX];
236 	unsigned int lines = 0;
237 	int n_argc;
238 	FILE *fp;
239 	char *cp;
240 	int err;
241 	int i;
242 
243 	if (argc < 2) {
244 		p_err("too few parameters for batch");
245 		return -1;
246 	} else if (!is_prefix(*argv, "file")) {
247 		p_err("expected 'file', got: %s", *argv);
248 		return -1;
249 	} else if (argc > 2) {
250 		p_err("too many parameters for batch");
251 		return -1;
252 	}
253 	NEXT_ARG();
254 
255 	if (!strcmp(*argv, "-"))
256 		fp = stdin;
257 	else
258 		fp = fopen(*argv, "r");
259 	if (!fp) {
260 		p_err("Can't open file (%s): %s", *argv, strerror(errno));
261 		return -1;
262 	}
263 
264 	if (json_output)
265 		jsonw_start_array(json_wtr);
266 	while (fgets(buf, sizeof(buf), fp)) {
267 		cp = strchr(buf, '#');
268 		if (cp)
269 			*cp = '\0';
270 
271 		if (strlen(buf) == sizeof(buf) - 1) {
272 			errno = E2BIG;
273 			break;
274 		}
275 
276 		/* Append continuation lines if any (coming after a line ending
277 		 * with '\' in the batch file).
278 		 */
279 		while ((cp = strstr(buf, "\\\n")) != NULL) {
280 			if (!fgets(contline, sizeof(contline), fp) ||
281 			    strlen(contline) == 0) {
282 				p_err("missing continuation line on command %d",
283 				      lines);
284 				err = -1;
285 				goto err_close;
286 			}
287 
288 			cp = strchr(contline, '#');
289 			if (cp)
290 				*cp = '\0';
291 
292 			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
293 				p_err("command %d is too long", lines);
294 				err = -1;
295 				goto err_close;
296 			}
297 			buf[strlen(buf) - 2] = '\0';
298 			strcat(buf, contline);
299 		}
300 
301 		n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
302 		if (!n_argc)
303 			continue;
304 		if (n_argc < 0)
305 			goto err_close;
306 
307 		if (json_output) {
308 			jsonw_start_object(json_wtr);
309 			jsonw_name(json_wtr, "command");
310 			jsonw_start_array(json_wtr);
311 			for (i = 0; i < n_argc; i++)
312 				jsonw_string(json_wtr, n_argv[i]);
313 			jsonw_end_array(json_wtr);
314 			jsonw_name(json_wtr, "output");
315 		}
316 
317 		err = cmd_select(cmds, n_argc, n_argv, do_help);
318 
319 		if (json_output)
320 			jsonw_end_object(json_wtr);
321 
322 		if (err)
323 			goto err_close;
324 
325 		lines++;
326 	}
327 
328 	if (errno && errno != ENOENT) {
329 		p_err("reading batch file failed: %s", strerror(errno));
330 		err = -1;
331 	} else {
332 		if (!json_output)
333 			printf("processed %d commands\n", lines);
334 		err = 0;
335 	}
336 err_close:
337 	if (fp != stdin)
338 		fclose(fp);
339 
340 	if (json_output)
341 		jsonw_end_array(json_wtr);
342 
343 	return err;
344 }
345 
346 int main(int argc, char **argv)
347 {
348 	static const struct option options[] = {
349 		{ "json",	no_argument,	NULL,	'j' },
350 		{ "help",	no_argument,	NULL,	'h' },
351 		{ "pretty",	no_argument,	NULL,	'p' },
352 		{ "version",	no_argument,	NULL,	'V' },
353 		{ "bpffs",	no_argument,	NULL,	'f' },
354 		{ "mapcompat",	no_argument,	NULL,	'm' },
355 		{ "nomount",	no_argument,	NULL,	'n' },
356 		{ "debug",	no_argument,	NULL,	'd' },
357 		{ 0 }
358 	};
359 	int opt, ret;
360 
361 	last_do_help = do_help;
362 	pretty_output = false;
363 	json_output = false;
364 	show_pinned = false;
365 	block_mount = false;
366 	bin_name = argv[0];
367 
368 	hash_init(prog_table.table);
369 	hash_init(map_table.table);
370 	hash_init(link_table.table);
371 
372 	opterr = 0;
373 	while ((opt = getopt_long(argc, argv, "Vhpjfmnd",
374 				  options, NULL)) >= 0) {
375 		switch (opt) {
376 		case 'V':
377 			return do_version(argc, argv);
378 		case 'h':
379 			return do_help(argc, argv);
380 		case 'p':
381 			pretty_output = true;
382 			/* fall through */
383 		case 'j':
384 			if (!json_output) {
385 				json_wtr = jsonw_new(stdout);
386 				if (!json_wtr) {
387 					p_err("failed to create JSON writer");
388 					return -1;
389 				}
390 				json_output = true;
391 			}
392 			jsonw_pretty(json_wtr, pretty_output);
393 			break;
394 		case 'f':
395 			show_pinned = true;
396 			break;
397 		case 'm':
398 			relaxed_maps = true;
399 			break;
400 		case 'n':
401 			block_mount = true;
402 			break;
403 		case 'd':
404 			libbpf_set_print(print_all_levels);
405 			verifier_logs = true;
406 			break;
407 		default:
408 			p_err("unrecognized option '%s'", argv[optind - 1]);
409 			if (json_output)
410 				clean_and_exit(-1);
411 			else
412 				usage();
413 		}
414 	}
415 
416 	argc -= optind;
417 	argv += optind;
418 	if (argc < 0)
419 		usage();
420 
421 	ret = cmd_select(cmds, argc, argv, do_help);
422 
423 	if (json_output)
424 		jsonw_destroy(&json_wtr);
425 
426 	if (show_pinned) {
427 		delete_pinned_obj_table(&prog_table);
428 		delete_pinned_obj_table(&map_table);
429 		delete_pinned_obj_table(&link_table);
430 	}
431 
432 	return ret;
433 }
434