main.c

  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
 22const char *bin_name;
 23static int last_argc;
 24static char **last_argv;
 25static int (*last_do_help)(int argc, char **argv);
 26json_writer_t *json_wtr;
 27bool pretty_output;
 28bool json_output;
 29bool show_pinned;
 30bool block_mount;
 31bool verifier_logs;
 32bool relaxed_maps;
 33bool use_loader;
 34struct btf *base_btf;
 35struct hashmap *refs_table;
 36bool sign_progs;
 37const char *private_key_path;
 38const char *cert_path;
 39
 40static void __noreturn clean_and_exit(int i)
 41{
 42	if (json_output)
 43		jsonw_destroy(&json_wtr);
 44
 45	exit(i);
 46}
 47
 48void usage(void)
 49{
 50	last_do_help(last_argc - 1, last_argv + 1);
 51
 52	clean_and_exit(-1);
 53}
 54
 55static int do_help(int argc, char **argv)
 56{
 57	if (json_output) {
 58		jsonw_null(json_wtr);
 59		return 0;
 60	}
 61
 62	fprintf(stderr,
 63		"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
 64		"       %s batch file FILE\n"
 65		"       %s version\n"
 66		"\n"
 67		"       OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter | token }\n"
 68		"       " HELP_SPEC_OPTIONS " |\n"
 69		"                    {-V|--version} }\n"
 70		"",
 71		bin_name, bin_name, bin_name);
 72
 73	return 0;
 74}
 75
 76static int do_batch(int argc, char **argv);
 77static int do_version(int argc, char **argv);
 78
 79static const struct cmd commands[] = {
 80	{ "help",	do_help },
 81	{ "batch",	do_batch },
 82	{ "prog",	do_prog },
 83	{ "map",	do_map },
 84	{ "link",	do_link },
 85	{ "cgroup",	do_cgroup },
 86	{ "perf",	do_perf },
 87	{ "net",	do_net },
 88	{ "feature",	do_feature },
 89	{ "btf",	do_btf },
 90	{ "gen",	do_gen },
 91	{ "struct_ops",	do_struct_ops },
 92	{ "iter",	do_iter },
 93	{ "token",	do_token },
 94	{ "version",	do_version },
 95	{ 0 }
 96};
 97
 98#ifndef BPFTOOL_VERSION
 99/* bpftool's major and minor version numbers are aligned on libbpf's. There is
100 * an offset of 6 for the version number, because bpftool's version was higher
101 * than libbpf's when we adopted this scheme. The patch number remains at 0
102 * for now. Set BPFTOOL_VERSION to override.
103 */
104#define BPFTOOL_MAJOR_VERSION (LIBBPF_MAJOR_VERSION + 6)
105#define BPFTOOL_MINOR_VERSION LIBBPF_MINOR_VERSION
106#define BPFTOOL_PATCH_VERSION 0
107#endif
108
109static void
110print_feature(const char *feature, bool state, unsigned int *nb_features)
111{
112	if (state) {
113		printf("%s %s", *nb_features ? "," : "", feature);
114		*nb_features = *nb_features + 1;
115	}
116}
117
118static int do_version(int argc, char **argv)
119{
120#ifdef HAVE_LIBBFD_SUPPORT
121	const bool has_libbfd = true;
122#else
123	const bool has_libbfd = false;
124#endif
125#ifdef HAVE_LLVM_SUPPORT
126	const bool has_llvm = true;
127#else
128	const bool has_llvm = false;
129#endif
130#ifdef BPFTOOL_WITHOUT_SKELETONS
131	const bool has_skeletons = false;
132#else
133	const bool has_skeletons = true;
134#endif
135	bool bootstrap = false;
136	int i;
137
138	for (i = 0; commands[i].cmd; i++) {
139		if (!strcmp(commands[i].cmd, "prog")) {
140			/* Assume we run a bootstrap version if "bpftool prog"
141			 * is not available.
142			 */
143			bootstrap = !commands[i].func;
144			break;
145		}
146	}
147
148	if (json_output) {
149		jsonw_start_object(json_wtr);	/* root object */
150
151		jsonw_name(json_wtr, "version");
152#ifdef BPFTOOL_VERSION
153		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
154#else
155		jsonw_printf(json_wtr, "\"%d.%d.%d\"", BPFTOOL_MAJOR_VERSION,
156			     BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
157#endif
158		jsonw_name(json_wtr, "libbpf_version");
159		jsonw_printf(json_wtr, "\"%u.%u\"",
160			     libbpf_major_version(), libbpf_minor_version());
161
162		jsonw_name(json_wtr, "features");
163		jsonw_start_object(json_wtr);	/* features */
164		jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
165		jsonw_bool_field(json_wtr, "llvm", has_llvm);
166		jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
167		jsonw_bool_field(json_wtr, "bootstrap", bootstrap);
168		jsonw_end_object(json_wtr);	/* features */
169
170		jsonw_end_object(json_wtr);	/* root object */
171	} else {
172		unsigned int nb_features = 0;
173
174#ifdef BPFTOOL_VERSION
175		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
176#else
177		printf("%s v%d.%d.%d\n", bin_name, BPFTOOL_MAJOR_VERSION,
178		       BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
179#endif
180		printf("using libbpf %s\n", libbpf_version_string());
181		printf("features:");
182		print_feature("libbfd", has_libbfd, &nb_features);
183		print_feature("llvm", has_llvm, &nb_features);
184		print_feature("skeletons", has_skeletons, &nb_features);
185		print_feature("bootstrap", bootstrap, &nb_features);
186		printf("\n");
187	}
188	return 0;
189}
190
191int cmd_select(const struct cmd *cmds, int argc, char **argv,
192	       int (*help)(int argc, char **argv))
193{
194	unsigned int i;
195
196	last_argc = argc;
197	last_argv = argv;
198	last_do_help = help;
199
200	if (argc < 1 && cmds[0].func)
201		return cmds[0].func(argc, argv);
202
203	for (i = 0; cmds[i].cmd; i++) {
204		if (is_prefix(*argv, cmds[i].cmd)) {
205			if (!cmds[i].func) {
206				p_err("command '%s' is not supported in bootstrap mode",
207				      cmds[i].cmd);
208				return -1;
209			}
210			return cmds[i].func(argc - 1, argv + 1);
211		}
212	}
213
214	help(argc - 1, argv + 1);
215
216	return -1;
217}
218
219bool is_prefix(const char *pfx, const char *str)
220{
221	if (!pfx)
222		return false;
223	if (strlen(str) < strlen(pfx))
224		return false;
225
226	return !memcmp(str, pfx, strlen(pfx));
227}
228
229/* Last argument MUST be NULL pointer */
230int detect_common_prefix(const char *arg, ...)
231{
232	unsigned int count = 0;
233	const char *ref;
234	char msg[256];
235	va_list ap;
236
237	snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
238	va_start(ap, arg);
239	while ((ref = va_arg(ap, const char *))) {
240		if (!is_prefix(arg, ref))
241			continue;
242		count++;
243		if (count > 1)
244			strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
245		strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
246	}
247	va_end(ap);
248	strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
249
250	if (count >= 2) {
251		p_err("%s", msg);
252		return -1;
253	}
254
255	return 0;
256}
257
258void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
259{
260	unsigned char *data = arg;
261	unsigned int i;
262
263	for (i = 0; i < n; i++) {
264		const char *pfx = "";
265
266		if (!i)
267			/* nothing */;
268		else if (!(i % 16))
269			fprintf(f, "\n");
270		else if (!(i % 8))
271			fprintf(f, "  ");
272		else
273			pfx = sep;
274
275		fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
276	}
277}
278
279/* Split command line into argument vector. */
280static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
281{
282	static const char ws[] = " \t\r\n";
283	char *cp = line;
284	int n_argc = 0;
285
286	while (*cp) {
287		/* Skip leading whitespace. */
288		cp += strspn(cp, ws);
289
290		if (*cp == '\0')
291			break;
292
293		if (n_argc >= (maxargs - 1)) {
294			p_err("too many arguments to command %d", cmd_nb);
295			return -1;
296		}
297
298		/* Word begins with quote. */
299		if (*cp == '\'' || *cp == '"') {
300			char quote = *cp++;
301
302			n_argv[n_argc++] = cp;
303			/* Find ending quote. */
304			cp = strchr(cp, quote);
305			if (!cp) {
306				p_err("unterminated quoted string in command %d",
307				      cmd_nb);
308				return -1;
309			}
310		} else {
311			n_argv[n_argc++] = cp;
312
313			/* Find end of word. */
314			cp += strcspn(cp, ws);
315			if (*cp == '\0')
316				break;
317		}
318
319		/* Separate words. */
320		*cp++ = 0;
321	}
322	n_argv[n_argc] = NULL;
323
324	return n_argc;
325}
326
327static int do_batch(int argc, char **argv)
328{
329	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
330	char *n_argv[BATCH_ARG_NB_MAX];
331	unsigned int lines = 0;
332	int n_argc;
333	FILE *fp;
334	char *cp;
335	int err = 0;
336	int i;
337
338	if (argc < 2) {
339		p_err("too few parameters for batch");
340		return -1;
341	} else if (argc > 2) {
342		p_err("too many parameters for batch");
343		return -1;
344	} else if (!is_prefix(*argv, "file")) {
345		p_err("expected 'file', got: %s", *argv);
346		return -1;
347	}
348	NEXT_ARG();
349
350	if (!strcmp(*argv, "-"))
351		fp = stdin;
352	else
353		fp = fopen(*argv, "r");
354	if (!fp) {
355		p_err("Can't open file (%s): %s", *argv, strerror(errno));
356		return -1;
357	}
358
359	if (json_output)
360		jsonw_start_array(json_wtr);
361	while (fgets(buf, sizeof(buf), fp)) {
362		cp = strchr(buf, '#');
363		if (cp)
364			*cp = '\0';
365
366		if (strlen(buf) == sizeof(buf) - 1) {
367			errno = E2BIG;
368			break;
369		}
370
371		/* Append continuation lines if any (coming after a line ending
372		 * with '\' in the batch file).
373		 */
374		while ((cp = strstr(buf, "\\\n")) != NULL) {
375			if (!fgets(contline, sizeof(contline), fp) ||
376			    strlen(contline) == 0) {
377				p_err("missing continuation line on command %u",
378				      lines);
379				err = -1;
380				goto err_close;
381			}
382
383			cp = strchr(contline, '#');
384			if (cp)
385				*cp = '\0';
386
387			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
388				p_err("command %u is too long", lines);
389				err = -1;
390				goto err_close;
391			}
392			buf[strlen(buf) - 2] = '\0';
393			strcat(buf, contline);
394		}
395
396		n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
397		if (!n_argc)
398			continue;
399		if (n_argc < 0) {
400			err = n_argc;
401			goto err_close;
402		}
403
404		if (json_output) {
405			jsonw_start_object(json_wtr);
406			jsonw_name(json_wtr, "command");
407			jsonw_start_array(json_wtr);
408			for (i = 0; i < n_argc; i++)
409				jsonw_string(json_wtr, n_argv[i]);
410			jsonw_end_array(json_wtr);
411			jsonw_name(json_wtr, "output");
412		}
413
414		err = cmd_select(commands, n_argc, n_argv, do_help);
415
416		if (json_output)
417			jsonw_end_object(json_wtr);
418
419		if (err)
420			goto err_close;
421
422		lines++;
423	}
424
425	if (errno && errno != ENOENT) {
426		p_err("reading batch file failed: %s", strerror(errno));
427		err = -1;
428	} else {
429		if (!json_output)
430			printf("processed %u commands\n", lines);
431	}
432err_close:
433	if (fp != stdin)
434		fclose(fp);
435
436	if (json_output)
437		jsonw_end_array(json_wtr);
438
439	return err;
440}
441
442int main(int argc, char **argv)
443{
444	static const struct option options[] = {
445		{ "json",	no_argument,	NULL,	'j' },
446		{ "help",	no_argument,	NULL,	'h' },
447		{ "pretty",	no_argument,	NULL,	'p' },
448		{ "version",	no_argument,	NULL,	'V' },
449		{ "bpffs",	no_argument,	NULL,	'f' },
450		{ "mapcompat",	no_argument,	NULL,	'm' },
451		{ "nomount",	no_argument,	NULL,	'n' },
452		{ "debug",	no_argument,	NULL,	'd' },
453		{ "use-loader",	no_argument,	NULL,	'L' },
454		{ "sign",	no_argument,	NULL,	'S' },
455		{ "base-btf",	required_argument, NULL, 'B' },
456		{ 0 }
457	};
458	bool version_requested = false;
459	int opt, ret;
460
461	setlinebuf(stdout);
462
463#ifdef USE_LIBCAP
464	/* Libcap < 2.63 hooks before main() to compute the number of
465	 * capabilities of the running kernel, and doing so it calls prctl()
466	 * which may fail and set errno to non-zero.
467	 * Let's reset errno to make sure this does not interfere with the
468	 * batch mode.
469	 */
470	errno = 0;
471#endif
472
473	last_do_help = do_help;
474	pretty_output = false;
475	json_output = false;
476	show_pinned = false;
477	block_mount = false;
478	bin_name = "bpftool";
479
480	opterr = 0;
481	while ((opt = getopt_long(argc, argv, "VhpjfLmndSi:k:B:l",
482				  options, NULL)) >= 0) {
483		switch (opt) {
484		case 'V':
485			version_requested = true;
486			break;
487		case 'h':
488			return do_help(argc, argv);
489		case 'p':
490			pretty_output = true;
491			/* fall through */
492		case 'j':
493			if (!json_output) {
494				json_wtr = jsonw_new(stdout);
495				if (!json_wtr) {
496					p_err("failed to create JSON writer");
497					return -1;
498				}
499				json_output = true;
500			}
501			jsonw_pretty(json_wtr, pretty_output);
502			break;
503		case 'f':
504			show_pinned = true;
505			break;
506		case 'm':
507			relaxed_maps = true;
508			break;
509		case 'n':
510			block_mount = true;
511			break;
512		case 'd':
513			libbpf_set_print(print_all_levels);
514			verifier_logs = true;
515			break;
516		case 'B':
517			base_btf = btf__parse(optarg, NULL);
518			if (!base_btf) {
519				p_err("failed to parse base BTF at '%s': %d\n",
520				      optarg, -errno);
521				return -1;
522			}
523			break;
524		case 'L':
525			use_loader = true;
526			break;
527		case 'S':
528			sign_progs = true;
529			use_loader = true;
530			break;
531		case 'k':
532			private_key_path = optarg;
533			break;
534		case 'i':
535			cert_path = optarg;
536			break;
537		default:
538			p_err("unrecognized option '%s'", argv[optind - 1]);
539			if (json_output)
540				clean_and_exit(-1);
541			else
542				usage();
543		}
544	}
545
546	argc -= optind;
547	argv += optind;
548	if (argc < 0)
549		usage();
550
551	if (sign_progs && (private_key_path == NULL || cert_path == NULL)) {
552		p_err("-i <identity_x509_cert> and -k <private_key> must be supplied with -S for signing");
553		return -EINVAL;
554	}
555
556	if (!sign_progs && (private_key_path != NULL || cert_path != NULL)) {
557		p_err("--sign (or -S) must be explicitly passed with -i <identity_x509_cert> and -k <private_key> to sign the programs");
558		return -EINVAL;
559	}
560
561	if (version_requested)
562		ret = do_version(argc, argv);
563	else
564		ret = cmd_select(commands, argc, argv, do_help);
565
566	if (json_output)
567		jsonw_destroy(&json_wtr);
568
569	btf__free(base_btf);
570
571	return ret;
572}