xref: /linux/tools/bpf/bpftool/main.c (revision 5c35a02c545a7bbe77f3a1ae337d9e29beed079b)
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 <bfd.h>
37 #include <ctype.h>
38 #include <errno.h>
39 #include <getopt.h>
40 #include <linux/bpf.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include <bpf.h>
46 
47 #include "main.h"
48 
49 #define BATCH_LINE_LEN_MAX 65536
50 #define BATCH_ARG_NB_MAX 4096
51 
52 const char *bin_name;
53 static int last_argc;
54 static char **last_argv;
55 static int (*last_do_help)(int argc, char **argv);
56 json_writer_t *json_wtr;
57 bool pretty_output;
58 bool json_output;
59 bool show_pinned;
60 struct pinned_obj_table prog_table;
61 struct pinned_obj_table map_table;
62 
63 static void __noreturn clean_and_exit(int i)
64 {
65 	if (json_output)
66 		jsonw_destroy(&json_wtr);
67 
68 	exit(i);
69 }
70 
71 void usage(void)
72 {
73 	last_do_help(last_argc - 1, last_argv + 1);
74 
75 	clean_and_exit(-1);
76 }
77 
78 static int do_help(int argc, char **argv)
79 {
80 	if (json_output) {
81 		jsonw_null(json_wtr);
82 		return 0;
83 	}
84 
85 	fprintf(stderr,
86 		"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
87 		"       %s batch file FILE\n"
88 		"       %s version\n"
89 		"\n"
90 		"       OBJECT := { prog | map | cgroup | perf }\n"
91 		"       " HELP_SPEC_OPTIONS "\n"
92 		"",
93 		bin_name, bin_name, bin_name);
94 
95 	return 0;
96 }
97 
98 static int do_version(int argc, char **argv)
99 {
100 	if (json_output) {
101 		jsonw_start_object(json_wtr);
102 		jsonw_name(json_wtr, "version");
103 		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
104 		jsonw_end_object(json_wtr);
105 	} else {
106 		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
107 	}
108 	return 0;
109 }
110 
111 int cmd_select(const struct cmd *cmds, int argc, char **argv,
112 	       int (*help)(int argc, char **argv))
113 {
114 	unsigned int i;
115 
116 	last_argc = argc;
117 	last_argv = argv;
118 	last_do_help = help;
119 
120 	if (argc < 1 && cmds[0].func)
121 		return cmds[0].func(argc, argv);
122 
123 	for (i = 0; cmds[i].func; i++)
124 		if (is_prefix(*argv, cmds[i].cmd))
125 			return cmds[i].func(argc - 1, argv + 1);
126 
127 	help(argc - 1, argv + 1);
128 
129 	return -1;
130 }
131 
132 bool is_prefix(const char *pfx, const char *str)
133 {
134 	if (!pfx)
135 		return false;
136 	if (strlen(str) < strlen(pfx))
137 		return false;
138 
139 	return !memcmp(str, pfx, strlen(pfx));
140 }
141 
142 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
143 {
144 	unsigned char *data = arg;
145 	unsigned int i;
146 
147 	for (i = 0; i < n; i++) {
148 		const char *pfx = "";
149 
150 		if (!i)
151 			/* nothing */;
152 		else if (!(i % 16))
153 			fprintf(f, "\n");
154 		else if (!(i % 8))
155 			fprintf(f, "  ");
156 		else
157 			pfx = sep;
158 
159 		fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
160 	}
161 }
162 
163 /* Split command line into argument vector. */
164 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
165 {
166 	static const char ws[] = " \t\r\n";
167 	char *cp = line;
168 	int n_argc = 0;
169 
170 	while (*cp) {
171 		/* Skip leading whitespace. */
172 		cp += strspn(cp, ws);
173 
174 		if (*cp == '\0')
175 			break;
176 
177 		if (n_argc >= (maxargs - 1)) {
178 			p_err("too many arguments to command %d", cmd_nb);
179 			return -1;
180 		}
181 
182 		/* Word begins with quote. */
183 		if (*cp == '\'' || *cp == '"') {
184 			char quote = *cp++;
185 
186 			n_argv[n_argc++] = cp;
187 			/* Find ending quote. */
188 			cp = strchr(cp, quote);
189 			if (!cp) {
190 				p_err("unterminated quoted string in command %d",
191 				      cmd_nb);
192 				return -1;
193 			}
194 		} else {
195 			n_argv[n_argc++] = cp;
196 
197 			/* Find end of word. */
198 			cp += strcspn(cp, ws);
199 			if (*cp == '\0')
200 				break;
201 		}
202 
203 		/* Separate words. */
204 		*cp++ = 0;
205 	}
206 	n_argv[n_argc] = NULL;
207 
208 	return n_argc;
209 }
210 
211 static int do_batch(int argc, char **argv);
212 
213 static const struct cmd cmds[] = {
214 	{ "help",	do_help },
215 	{ "batch",	do_batch },
216 	{ "prog",	do_prog },
217 	{ "map",	do_map },
218 	{ "cgroup",	do_cgroup },
219 	{ "perf",	do_perf },
220 	{ "version",	do_version },
221 	{ 0 }
222 };
223 
224 static int do_batch(int argc, char **argv)
225 {
226 	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
227 	char *n_argv[BATCH_ARG_NB_MAX];
228 	unsigned int lines = 0;
229 	int n_argc;
230 	FILE *fp;
231 	char *cp;
232 	int err;
233 	int i;
234 
235 	if (argc < 2) {
236 		p_err("too few parameters for batch");
237 		return -1;
238 	} else if (!is_prefix(*argv, "file")) {
239 		p_err("expected 'file', got: %s", *argv);
240 		return -1;
241 	} else if (argc > 2) {
242 		p_err("too many parameters for batch");
243 		return -1;
244 	}
245 	NEXT_ARG();
246 
247 	if (!strcmp(*argv, "-"))
248 		fp = stdin;
249 	else
250 		fp = fopen(*argv, "r");
251 	if (!fp) {
252 		p_err("Can't open file (%s): %s", *argv, strerror(errno));
253 		return -1;
254 	}
255 
256 	if (json_output)
257 		jsonw_start_array(json_wtr);
258 	while (fgets(buf, sizeof(buf), fp)) {
259 		cp = strchr(buf, '#');
260 		if (cp)
261 			*cp = '\0';
262 
263 		if (strlen(buf) == sizeof(buf) - 1) {
264 			errno = E2BIG;
265 			break;
266 		}
267 
268 		/* Append continuation lines if any (coming after a line ending
269 		 * with '\' in the batch file).
270 		 */
271 		while ((cp = strstr(buf, "\\\n")) != NULL) {
272 			if (!fgets(contline, sizeof(contline), fp) ||
273 			    strlen(contline) == 0) {
274 				p_err("missing continuation line on command %d",
275 				      lines);
276 				err = -1;
277 				goto err_close;
278 			}
279 
280 			cp = strchr(contline, '#');
281 			if (cp)
282 				*cp = '\0';
283 
284 			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
285 				p_err("command %d is too long", lines);
286 				err = -1;
287 				goto err_close;
288 			}
289 			buf[strlen(buf) - 2] = '\0';
290 			strcat(buf, contline);
291 		}
292 
293 		n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
294 		if (!n_argc)
295 			continue;
296 		if (n_argc < 0)
297 			goto err_close;
298 
299 		if (json_output) {
300 			jsonw_start_object(json_wtr);
301 			jsonw_name(json_wtr, "command");
302 			jsonw_start_array(json_wtr);
303 			for (i = 0; i < n_argc; i++)
304 				jsonw_string(json_wtr, n_argv[i]);
305 			jsonw_end_array(json_wtr);
306 			jsonw_name(json_wtr, "output");
307 		}
308 
309 		err = cmd_select(cmds, n_argc, n_argv, do_help);
310 
311 		if (json_output)
312 			jsonw_end_object(json_wtr);
313 
314 		if (err)
315 			goto err_close;
316 
317 		lines++;
318 	}
319 
320 	if (errno && errno != ENOENT) {
321 		p_err("reading batch file failed: %s", strerror(errno));
322 		err = -1;
323 	} else {
324 		p_info("processed %d commands", lines);
325 		err = 0;
326 	}
327 err_close:
328 	if (fp != stdin)
329 		fclose(fp);
330 
331 	if (json_output)
332 		jsonw_end_array(json_wtr);
333 
334 	return err;
335 }
336 
337 int main(int argc, char **argv)
338 {
339 	static const struct option options[] = {
340 		{ "json",	no_argument,	NULL,	'j' },
341 		{ "help",	no_argument,	NULL,	'h' },
342 		{ "pretty",	no_argument,	NULL,	'p' },
343 		{ "version",	no_argument,	NULL,	'V' },
344 		{ "bpffs",	no_argument,	NULL,	'f' },
345 		{ 0 }
346 	};
347 	int opt, ret;
348 
349 	last_do_help = do_help;
350 	pretty_output = false;
351 	json_output = false;
352 	show_pinned = false;
353 	bin_name = argv[0];
354 
355 	hash_init(prog_table.table);
356 	hash_init(map_table.table);
357 
358 	opterr = 0;
359 	while ((opt = getopt_long(argc, argv, "Vhpjf",
360 				  options, NULL)) >= 0) {
361 		switch (opt) {
362 		case 'V':
363 			return do_version(argc, argv);
364 		case 'h':
365 			return do_help(argc, argv);
366 		case 'p':
367 			pretty_output = true;
368 			/* fall through */
369 		case 'j':
370 			if (!json_output) {
371 				json_wtr = jsonw_new(stdout);
372 				if (!json_wtr) {
373 					p_err("failed to create JSON writer");
374 					return -1;
375 				}
376 				json_output = true;
377 			}
378 			jsonw_pretty(json_wtr, pretty_output);
379 			break;
380 		case 'f':
381 			show_pinned = true;
382 			break;
383 		default:
384 			p_err("unrecognized option '%s'", argv[optind - 1]);
385 			if (json_output)
386 				clean_and_exit(-1);
387 			else
388 				usage();
389 		}
390 	}
391 
392 	argc -= optind;
393 	argv += optind;
394 	if (argc < 0)
395 		usage();
396 
397 	bfd_init();
398 
399 	ret = cmd_select(cmds, argc, argv, do_help);
400 
401 	if (json_output)
402 		jsonw_destroy(&json_wtr);
403 
404 	if (show_pinned) {
405 		delete_pinned_obj_table(&prog_table);
406 		delete_pinned_obj_table(&map_table);
407 	}
408 
409 	return ret;
410 }
411