xref: /openbmc/linux/tools/bpf/bpftool/common.c (revision 82e8d723)
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.h>
24 #include <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_by_id)(__u32))
215 {
216 	unsigned int id;
217 	char *endptr;
218 	int err;
219 	int fd;
220 
221 	if (argc < 3) {
222 		p_err("too few arguments, id ID and FILE path is required");
223 		return -1;
224 	} else if (argc > 3) {
225 		p_err("too many arguments");
226 		return -1;
227 	}
228 
229 	if (!is_prefix(*argv, "id")) {
230 		p_err("expected 'id' got %s", *argv);
231 		return -1;
232 	}
233 	NEXT_ARG();
234 
235 	id = strtoul(*argv, &endptr, 0);
236 	if (*endptr) {
237 		p_err("can't parse %s as ID", *argv);
238 		return -1;
239 	}
240 	NEXT_ARG();
241 
242 	fd = get_fd_by_id(id);
243 	if (fd < 0) {
244 		p_err("can't open object by id (%u): %s", id, strerror(errno));
245 		return -1;
246 	}
247 
248 	err = do_pin_fd(fd, *argv);
249 
250 	close(fd);
251 	return err;
252 }
253 
254 const char *get_fd_type_name(enum bpf_obj_type type)
255 {
256 	static const char * const names[] = {
257 		[BPF_OBJ_UNKNOWN]	= "unknown",
258 		[BPF_OBJ_PROG]		= "prog",
259 		[BPF_OBJ_MAP]		= "map",
260 	};
261 
262 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
263 		return names[BPF_OBJ_UNKNOWN];
264 
265 	return names[type];
266 }
267 
268 int get_fd_type(int fd)
269 {
270 	char path[PATH_MAX];
271 	char buf[512];
272 	ssize_t n;
273 
274 	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
275 
276 	n = readlink(path, buf, sizeof(buf));
277 	if (n < 0) {
278 		p_err("can't read link type: %s", strerror(errno));
279 		return -1;
280 	}
281 	if (n == sizeof(path)) {
282 		p_err("can't read link type: path too long!");
283 		return -1;
284 	}
285 
286 	if (strstr(buf, "bpf-map"))
287 		return BPF_OBJ_MAP;
288 	else if (strstr(buf, "bpf-prog"))
289 		return BPF_OBJ_PROG;
290 
291 	return BPF_OBJ_UNKNOWN;
292 }
293 
294 char *get_fdinfo(int fd, const char *key)
295 {
296 	char path[PATH_MAX];
297 	char *line = NULL;
298 	size_t line_n = 0;
299 	ssize_t n;
300 	FILE *fdi;
301 
302 	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
303 
304 	fdi = fopen(path, "r");
305 	if (!fdi)
306 		return NULL;
307 
308 	while ((n = getline(&line, &line_n, fdi)) > 0) {
309 		char *value;
310 		int len;
311 
312 		if (!strstr(line, key))
313 			continue;
314 
315 		fclose(fdi);
316 
317 		value = strchr(line, '\t');
318 		if (!value || !value[1]) {
319 			free(line);
320 			return NULL;
321 		}
322 		value++;
323 
324 		len = strlen(value);
325 		memmove(line, value, len);
326 		line[len - 1] = '\0';
327 
328 		return line;
329 	}
330 
331 	free(line);
332 	fclose(fdi);
333 	return NULL;
334 }
335 
336 void print_data_json(uint8_t *data, size_t len)
337 {
338 	unsigned int i;
339 
340 	jsonw_start_array(json_wtr);
341 	for (i = 0; i < len; i++)
342 		jsonw_printf(json_wtr, "%d", data[i]);
343 	jsonw_end_array(json_wtr);
344 }
345 
346 void print_hex_data_json(uint8_t *data, size_t len)
347 {
348 	unsigned int i;
349 
350 	jsonw_start_array(json_wtr);
351 	for (i = 0; i < len; i++)
352 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
353 	jsonw_end_array(json_wtr);
354 }
355 
356 int build_pinned_obj_table(struct pinned_obj_table *tab,
357 			   enum bpf_obj_type type)
358 {
359 	struct bpf_prog_info pinned_info = {};
360 	struct pinned_obj *obj_node = NULL;
361 	__u32 len = sizeof(pinned_info);
362 	struct mntent *mntent = NULL;
363 	enum bpf_obj_type objtype;
364 	FILE *mntfile = NULL;
365 	FTSENT *ftse = NULL;
366 	FTS *fts = NULL;
367 	int fd, err;
368 
369 	mntfile = setmntent("/proc/mounts", "r");
370 	if (!mntfile)
371 		return -1;
372 
373 	while ((mntent = getmntent(mntfile))) {
374 		char *path[] = { mntent->mnt_dir, NULL };
375 
376 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
377 			continue;
378 
379 		fts = fts_open(path, 0, NULL);
380 		if (!fts)
381 			continue;
382 
383 		while ((ftse = fts_read(fts))) {
384 			if (!(ftse->fts_info & FTS_F))
385 				continue;
386 			fd = open_obj_pinned(ftse->fts_path, true);
387 			if (fd < 0)
388 				continue;
389 
390 			objtype = get_fd_type(fd);
391 			if (objtype != type) {
392 				close(fd);
393 				continue;
394 			}
395 			memset(&pinned_info, 0, sizeof(pinned_info));
396 			err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
397 			if (err) {
398 				close(fd);
399 				continue;
400 			}
401 
402 			obj_node = malloc(sizeof(*obj_node));
403 			if (!obj_node) {
404 				close(fd);
405 				fts_close(fts);
406 				fclose(mntfile);
407 				return -1;
408 			}
409 
410 			memset(obj_node, 0, sizeof(*obj_node));
411 			obj_node->id = pinned_info.id;
412 			obj_node->path = strdup(ftse->fts_path);
413 			hash_add(tab->table, &obj_node->hash, obj_node->id);
414 
415 			close(fd);
416 		}
417 		fts_close(fts);
418 	}
419 	fclose(mntfile);
420 	return 0;
421 }
422 
423 void delete_pinned_obj_table(struct pinned_obj_table *tab)
424 {
425 	struct pinned_obj *obj;
426 	struct hlist_node *tmp;
427 	unsigned int bkt;
428 
429 	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
430 		hash_del(&obj->hash);
431 		free(obj->path);
432 		free(obj);
433 	}
434 }
435 
436 unsigned int get_page_size(void)
437 {
438 	static int result;
439 
440 	if (!result)
441 		result = getpagesize();
442 	return result;
443 }
444 
445 unsigned int get_possible_cpus(void)
446 {
447 	int cpus = libbpf_num_possible_cpus();
448 
449 	if (cpus < 0) {
450 		p_err("Can't get # of possible cpus: %s", strerror(-cpus));
451 		exit(-1);
452 	}
453 	return cpus;
454 }
455 
456 static char *
457 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
458 {
459 	struct stat st;
460 	int err;
461 
462 	err = stat("/proc/self/ns/net", &st);
463 	if (err) {
464 		p_err("Can't stat /proc/self: %s", strerror(errno));
465 		return NULL;
466 	}
467 
468 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
469 		return NULL;
470 
471 	return if_indextoname(ifindex, buf);
472 }
473 
474 static int read_sysfs_hex_int(char *path)
475 {
476 	char vendor_id_buf[8];
477 	int len;
478 	int fd;
479 
480 	fd = open(path, O_RDONLY);
481 	if (fd < 0) {
482 		p_err("Can't open %s: %s", path, strerror(errno));
483 		return -1;
484 	}
485 
486 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
487 	close(fd);
488 	if (len < 0) {
489 		p_err("Can't read %s: %s", path, strerror(errno));
490 		return -1;
491 	}
492 	if (len >= (int)sizeof(vendor_id_buf)) {
493 		p_err("Value in %s too long", path);
494 		return -1;
495 	}
496 
497 	vendor_id_buf[len] = 0;
498 
499 	return strtol(vendor_id_buf, NULL, 0);
500 }
501 
502 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
503 {
504 	char full_path[64];
505 
506 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
507 		 devname, entry_name);
508 
509 	return read_sysfs_hex_int(full_path);
510 }
511 
512 const char *
513 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
514 		      const char **opt)
515 {
516 	char devname[IF_NAMESIZE];
517 	int vendor_id;
518 	int device_id;
519 
520 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
521 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
522 		      strerror(errno));
523 		return NULL;
524 	}
525 
526 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
527 	if (vendor_id < 0) {
528 		p_err("Can't get device vendor id for %s", devname);
529 		return NULL;
530 	}
531 
532 	switch (vendor_id) {
533 	case 0x19ee:
534 		device_id = read_sysfs_netdev_hex_int(devname, "device");
535 		if (device_id != 0x4000 &&
536 		    device_id != 0x6000 &&
537 		    device_id != 0x6003)
538 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
539 		*opt = "ctx4";
540 		return "NFP-6xxx";
541 	default:
542 		p_err("Can't get bfd arch name for device vendor id 0x%04x",
543 		      vendor_id);
544 		return NULL;
545 	}
546 }
547 
548 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
549 {
550 	char name[IF_NAMESIZE];
551 
552 	if (!ifindex)
553 		return;
554 
555 	printf("  offloaded_to ");
556 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
557 		printf("%s", name);
558 	else
559 		printf("ifindex %u ns_dev %llu ns_ino %llu",
560 		       ifindex, ns_dev, ns_inode);
561 }
562 
563 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
564 {
565 	char name[IF_NAMESIZE];
566 
567 	if (!ifindex)
568 		return;
569 
570 	jsonw_name(json_wtr, "dev");
571 	jsonw_start_object(json_wtr);
572 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
573 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
574 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
575 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
576 		jsonw_string_field(json_wtr, "ifname", name);
577 	jsonw_end_object(json_wtr);
578 }
579 
580 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
581 {
582 	char *endptr;
583 
584 	NEXT_ARGP();
585 
586 	if (*val) {
587 		p_err("%s already specified", what);
588 		return -1;
589 	}
590 
591 	*val = strtoul(**argv, &endptr, 0);
592 	if (*endptr) {
593 		p_err("can't parse %s as %s", **argv, what);
594 		return -1;
595 	}
596 	NEXT_ARGP();
597 
598 	return 0;
599 }
600