xref: /linux/tools/bpf/bpftool/common.c (revision 37744feebc086908fd89760650f458ab19071750)
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 <fcntl.h>
7 #include <fts.h>
8 #include <libgen.h>
9 #include <mntent.h>
10 #include <stdbool.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <unistd.h>
15 #include <linux/limits.h>
16 #include <linux/magic.h>
17 #include <net/if.h>
18 #include <sys/mount.h>
19 #include <sys/resource.h>
20 #include <sys/stat.h>
21 #include <sys/vfs.h>
22 
23 #include <bpf/bpf.h>
24 #include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
25 
26 #include "main.h"
27 
28 #ifndef BPF_FS_MAGIC
29 #define BPF_FS_MAGIC		0xcafe4a11
30 #endif
31 
32 void p_err(const char *fmt, ...)
33 {
34 	va_list ap;
35 
36 	va_start(ap, fmt);
37 	if (json_output) {
38 		jsonw_start_object(json_wtr);
39 		jsonw_name(json_wtr, "error");
40 		jsonw_vprintf_enquote(json_wtr, fmt, ap);
41 		jsonw_end_object(json_wtr);
42 	} else {
43 		fprintf(stderr, "Error: ");
44 		vfprintf(stderr, fmt, ap);
45 		fprintf(stderr, "\n");
46 	}
47 	va_end(ap);
48 }
49 
50 void p_info(const char *fmt, ...)
51 {
52 	va_list ap;
53 
54 	if (json_output)
55 		return;
56 
57 	va_start(ap, fmt);
58 	vfprintf(stderr, fmt, ap);
59 	fprintf(stderr, "\n");
60 	va_end(ap);
61 }
62 
63 static bool is_bpffs(char *path)
64 {
65 	struct statfs st_fs;
66 
67 	if (statfs(path, &st_fs) < 0)
68 		return false;
69 
70 	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
71 }
72 
73 void set_max_rlimit(void)
74 {
75 	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
76 
77 	setrlimit(RLIMIT_MEMLOCK, &rinf);
78 }
79 
80 static int
81 mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
82 {
83 	bool bind_done = false;
84 
85 	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
86 		if (errno != EINVAL || bind_done) {
87 			snprintf(buff, bufflen,
88 				 "mount --make-private %s failed: %s",
89 				 target, strerror(errno));
90 			return -1;
91 		}
92 
93 		if (mount(target, target, "none", MS_BIND, NULL)) {
94 			snprintf(buff, bufflen,
95 				 "mount --bind %s %s failed: %s",
96 				 target, target, strerror(errno));
97 			return -1;
98 		}
99 
100 		bind_done = true;
101 	}
102 
103 	if (mount(type, target, type, 0, "mode=0700")) {
104 		snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
105 			 type, type, target, strerror(errno));
106 		return -1;
107 	}
108 
109 	return 0;
110 }
111 
112 int mount_tracefs(const char *target)
113 {
114 	char err_str[ERR_MAX_LEN];
115 	int err;
116 
117 	err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
118 	if (err) {
119 		err_str[ERR_MAX_LEN - 1] = '\0';
120 		p_err("can't mount tracefs: %s", err_str);
121 	}
122 
123 	return err;
124 }
125 
126 int open_obj_pinned(char *path, bool quiet)
127 {
128 	int fd;
129 
130 	fd = bpf_obj_get(path);
131 	if (fd < 0) {
132 		if (!quiet)
133 			p_err("bpf obj get (%s): %s", path,
134 			      errno == EACCES && !is_bpffs(dirname(path)) ?
135 			    "directory not in bpf file system (bpffs)" :
136 			    strerror(errno));
137 		return -1;
138 	}
139 
140 	return fd;
141 }
142 
143 int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
144 {
145 	enum bpf_obj_type type;
146 	int fd;
147 
148 	fd = open_obj_pinned(path, false);
149 	if (fd < 0)
150 		return -1;
151 
152 	type = get_fd_type(fd);
153 	if (type < 0) {
154 		close(fd);
155 		return type;
156 	}
157 	if (type != exp_type) {
158 		p_err("incorrect object type: %s", get_fd_type_name(type));
159 		close(fd);
160 		return -1;
161 	}
162 
163 	return fd;
164 }
165 
166 int mount_bpffs_for_pin(const char *name)
167 {
168 	char err_str[ERR_MAX_LEN];
169 	char *file;
170 	char *dir;
171 	int err = 0;
172 
173 	file = malloc(strlen(name) + 1);
174 	strcpy(file, name);
175 	dir = dirname(file);
176 
177 	if (is_bpffs(dir))
178 		/* nothing to do if already mounted */
179 		goto out_free;
180 
181 	if (block_mount) {
182 		p_err("no BPF file system found, not mounting it due to --nomount option");
183 		err = -1;
184 		goto out_free;
185 	}
186 
187 	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
188 	if (err) {
189 		err_str[ERR_MAX_LEN - 1] = '\0';
190 		p_err("can't mount BPF file system to pin the object (%s): %s",
191 		      name, err_str);
192 	}
193 
194 out_free:
195 	free(file);
196 	return err;
197 }
198 
199 int do_pin_fd(int fd, const char *name)
200 {
201 	int err;
202 
203 	err = mount_bpffs_for_pin(name);
204 	if (err)
205 		return err;
206 
207 	err = bpf_obj_pin(fd, name);
208 	if (err)
209 		p_err("can't pin the object (%s): %s", name, strerror(errno));
210 
211 	return err;
212 }
213 
214 int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
215 {
216 	int err;
217 	int fd;
218 
219 	fd = get_fd(&argc, &argv);
220 	if (fd < 0)
221 		return fd;
222 
223 	err = do_pin_fd(fd, *argv);
224 
225 	close(fd);
226 	return err;
227 }
228 
229 const char *get_fd_type_name(enum bpf_obj_type type)
230 {
231 	static const char * const names[] = {
232 		[BPF_OBJ_UNKNOWN]	= "unknown",
233 		[BPF_OBJ_PROG]		= "prog",
234 		[BPF_OBJ_MAP]		= "map",
235 	};
236 
237 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
238 		return names[BPF_OBJ_UNKNOWN];
239 
240 	return names[type];
241 }
242 
243 int get_fd_type(int fd)
244 {
245 	char path[PATH_MAX];
246 	char buf[512];
247 	ssize_t n;
248 
249 	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
250 
251 	n = readlink(path, buf, sizeof(buf));
252 	if (n < 0) {
253 		p_err("can't read link type: %s", strerror(errno));
254 		return -1;
255 	}
256 	if (n == sizeof(path)) {
257 		p_err("can't read link type: path too long!");
258 		return -1;
259 	}
260 
261 	if (strstr(buf, "bpf-map"))
262 		return BPF_OBJ_MAP;
263 	else if (strstr(buf, "bpf-prog"))
264 		return BPF_OBJ_PROG;
265 
266 	return BPF_OBJ_UNKNOWN;
267 }
268 
269 char *get_fdinfo(int fd, const char *key)
270 {
271 	char path[PATH_MAX];
272 	char *line = NULL;
273 	size_t line_n = 0;
274 	ssize_t n;
275 	FILE *fdi;
276 
277 	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
278 
279 	fdi = fopen(path, "r");
280 	if (!fdi)
281 		return NULL;
282 
283 	while ((n = getline(&line, &line_n, fdi)) > 0) {
284 		char *value;
285 		int len;
286 
287 		if (!strstr(line, key))
288 			continue;
289 
290 		fclose(fdi);
291 
292 		value = strchr(line, '\t');
293 		if (!value || !value[1]) {
294 			free(line);
295 			return NULL;
296 		}
297 		value++;
298 
299 		len = strlen(value);
300 		memmove(line, value, len);
301 		line[len - 1] = '\0';
302 
303 		return line;
304 	}
305 
306 	free(line);
307 	fclose(fdi);
308 	return NULL;
309 }
310 
311 void print_data_json(uint8_t *data, size_t len)
312 {
313 	unsigned int i;
314 
315 	jsonw_start_array(json_wtr);
316 	for (i = 0; i < len; i++)
317 		jsonw_printf(json_wtr, "%d", data[i]);
318 	jsonw_end_array(json_wtr);
319 }
320 
321 void print_hex_data_json(uint8_t *data, size_t len)
322 {
323 	unsigned int i;
324 
325 	jsonw_start_array(json_wtr);
326 	for (i = 0; i < len; i++)
327 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
328 	jsonw_end_array(json_wtr);
329 }
330 
331 int build_pinned_obj_table(struct pinned_obj_table *tab,
332 			   enum bpf_obj_type type)
333 {
334 	struct bpf_prog_info pinned_info = {};
335 	struct pinned_obj *obj_node = NULL;
336 	__u32 len = sizeof(pinned_info);
337 	struct mntent *mntent = NULL;
338 	enum bpf_obj_type objtype;
339 	FILE *mntfile = NULL;
340 	FTSENT *ftse = NULL;
341 	FTS *fts = NULL;
342 	int fd, err;
343 
344 	mntfile = setmntent("/proc/mounts", "r");
345 	if (!mntfile)
346 		return -1;
347 
348 	while ((mntent = getmntent(mntfile))) {
349 		char *path[] = { mntent->mnt_dir, NULL };
350 
351 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
352 			continue;
353 
354 		fts = fts_open(path, 0, NULL);
355 		if (!fts)
356 			continue;
357 
358 		while ((ftse = fts_read(fts))) {
359 			if (!(ftse->fts_info & FTS_F))
360 				continue;
361 			fd = open_obj_pinned(ftse->fts_path, true);
362 			if (fd < 0)
363 				continue;
364 
365 			objtype = get_fd_type(fd);
366 			if (objtype != type) {
367 				close(fd);
368 				continue;
369 			}
370 			memset(&pinned_info, 0, sizeof(pinned_info));
371 			err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
372 			if (err) {
373 				close(fd);
374 				continue;
375 			}
376 
377 			obj_node = malloc(sizeof(*obj_node));
378 			if (!obj_node) {
379 				close(fd);
380 				fts_close(fts);
381 				fclose(mntfile);
382 				return -1;
383 			}
384 
385 			memset(obj_node, 0, sizeof(*obj_node));
386 			obj_node->id = pinned_info.id;
387 			obj_node->path = strdup(ftse->fts_path);
388 			hash_add(tab->table, &obj_node->hash, obj_node->id);
389 
390 			close(fd);
391 		}
392 		fts_close(fts);
393 	}
394 	fclose(mntfile);
395 	return 0;
396 }
397 
398 void delete_pinned_obj_table(struct pinned_obj_table *tab)
399 {
400 	struct pinned_obj *obj;
401 	struct hlist_node *tmp;
402 	unsigned int bkt;
403 
404 	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
405 		hash_del(&obj->hash);
406 		free(obj->path);
407 		free(obj);
408 	}
409 }
410 
411 unsigned int get_page_size(void)
412 {
413 	static int result;
414 
415 	if (!result)
416 		result = getpagesize();
417 	return result;
418 }
419 
420 unsigned int get_possible_cpus(void)
421 {
422 	int cpus = libbpf_num_possible_cpus();
423 
424 	if (cpus < 0) {
425 		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
426 		exit(-1);
427 	}
428 	return cpus;
429 }
430 
431 static char *
432 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
433 {
434 	struct stat st;
435 	int err;
436 
437 	err = stat("/proc/self/ns/net", &st);
438 	if (err) {
439 		p_err("Can't stat /proc/self: %s", strerror(errno));
440 		return NULL;
441 	}
442 
443 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
444 		return NULL;
445 
446 	return if_indextoname(ifindex, buf);
447 }
448 
449 static int read_sysfs_hex_int(char *path)
450 {
451 	char vendor_id_buf[8];
452 	int len;
453 	int fd;
454 
455 	fd = open(path, O_RDONLY);
456 	if (fd < 0) {
457 		p_err("Can't open %s: %s", path, strerror(errno));
458 		return -1;
459 	}
460 
461 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
462 	close(fd);
463 	if (len < 0) {
464 		p_err("Can't read %s: %s", path, strerror(errno));
465 		return -1;
466 	}
467 	if (len >= (int)sizeof(vendor_id_buf)) {
468 		p_err("Value in %s too long", path);
469 		return -1;
470 	}
471 
472 	vendor_id_buf[len] = 0;
473 
474 	return strtol(vendor_id_buf, NULL, 0);
475 }
476 
477 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
478 {
479 	char full_path[64];
480 
481 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
482 		 devname, entry_name);
483 
484 	return read_sysfs_hex_int(full_path);
485 }
486 
487 const char *
488 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
489 		      const char **opt)
490 {
491 	char devname[IF_NAMESIZE];
492 	int vendor_id;
493 	int device_id;
494 
495 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
496 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
497 		      strerror(errno));
498 		return NULL;
499 	}
500 
501 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
502 	if (vendor_id < 0) {
503 		p_err("Can't get device vendor id for %s", devname);
504 		return NULL;
505 	}
506 
507 	switch (vendor_id) {
508 	case 0x19ee:
509 		device_id = read_sysfs_netdev_hex_int(devname, "device");
510 		if (device_id != 0x4000 &&
511 		    device_id != 0x6000 &&
512 		    device_id != 0x6003)
513 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
514 		*opt = "ctx4";
515 		return "NFP-6xxx";
516 	default:
517 		p_err("Can't get bfd arch name for device vendor id 0x%04x",
518 		      vendor_id);
519 		return NULL;
520 	}
521 }
522 
523 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
524 {
525 	char name[IF_NAMESIZE];
526 
527 	if (!ifindex)
528 		return;
529 
530 	printf("  offloaded_to ");
531 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
532 		printf("%s", name);
533 	else
534 		printf("ifindex %u ns_dev %llu ns_ino %llu",
535 		       ifindex, ns_dev, ns_inode);
536 }
537 
538 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
539 {
540 	char name[IF_NAMESIZE];
541 
542 	if (!ifindex)
543 		return;
544 
545 	jsonw_name(json_wtr, "dev");
546 	jsonw_start_object(json_wtr);
547 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
548 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
549 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
550 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
551 		jsonw_string_field(json_wtr, "ifname", name);
552 	jsonw_end_object(json_wtr);
553 }
554 
555 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
556 {
557 	char *endptr;
558 
559 	NEXT_ARGP();
560 
561 	if (*val) {
562 		p_err("%s already specified", what);
563 		return -1;
564 	}
565 
566 	*val = strtoul(**argv, &endptr, 0);
567 	if (*endptr) {
568 		p_err("can't parse %s as %s", **argv, what);
569 		return -1;
570 	}
571 	NEXT_ARGP();
572 
573 	return 0;
574 }
575 
576 int __printf(2, 0)
577 print_all_levels(__maybe_unused enum libbpf_print_level level,
578 		 const char *format, va_list args)
579 {
580 	return vfprintf(stderr, format, args);
581 }
582