xref: /openbmc/linux/tools/bpf/bpftool/common.c (revision 0c3df9ed)
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 
25 #include "main.h"
26 
27 #ifndef BPF_FS_MAGIC
28 #define BPF_FS_MAGIC		0xcafe4a11
29 #endif
30 
31 void __printf(1, 2) p_err(const char *fmt, ...)
32 {
33 	va_list ap;
34 
35 	va_start(ap, fmt);
36 	if (json_output) {
37 		jsonw_start_object(json_wtr);
38 		jsonw_name(json_wtr, "error");
39 		jsonw_vprintf_enquote(json_wtr, fmt, ap);
40 		jsonw_end_object(json_wtr);
41 	} else {
42 		fprintf(stderr, "Error: ");
43 		vfprintf(stderr, fmt, ap);
44 		fprintf(stderr, "\n");
45 	}
46 	va_end(ap);
47 }
48 
49 void __printf(1, 2) p_info(const char *fmt, ...)
50 {
51 	va_list ap;
52 
53 	if (json_output)
54 		return;
55 
56 	va_start(ap, fmt);
57 	vfprintf(stderr, fmt, ap);
58 	fprintf(stderr, "\n");
59 	va_end(ap);
60 }
61 
62 static bool is_bpffs(char *path)
63 {
64 	struct statfs st_fs;
65 
66 	if (statfs(path, &st_fs) < 0)
67 		return false;
68 
69 	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
70 }
71 
72 void set_max_rlimit(void)
73 {
74 	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
75 
76 	setrlimit(RLIMIT_MEMLOCK, &rinf);
77 }
78 
79 static int
80 mnt_fs(const char *target, const char *type, char *buff, size_t bufflen)
81 {
82 	bool bind_done = false;
83 
84 	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
85 		if (errno != EINVAL || bind_done) {
86 			snprintf(buff, bufflen,
87 				 "mount --make-private %s failed: %s",
88 				 target, strerror(errno));
89 			return -1;
90 		}
91 
92 		if (mount(target, target, "none", MS_BIND, NULL)) {
93 			snprintf(buff, bufflen,
94 				 "mount --bind %s %s failed: %s",
95 				 target, target, strerror(errno));
96 			return -1;
97 		}
98 
99 		bind_done = true;
100 	}
101 
102 	if (mount(type, target, type, 0, "mode=0700")) {
103 		snprintf(buff, bufflen, "mount -t %s %s %s failed: %s",
104 			 type, type, target, strerror(errno));
105 		return -1;
106 	}
107 
108 	return 0;
109 }
110 
111 int mount_tracefs(const char *target)
112 {
113 	char err_str[ERR_MAX_LEN];
114 	int err;
115 
116 	err = mnt_fs(target, "tracefs", err_str, ERR_MAX_LEN);
117 	if (err) {
118 		err_str[ERR_MAX_LEN - 1] = '\0';
119 		p_err("can't mount tracefs: %s", err_str);
120 	}
121 
122 	return err;
123 }
124 
125 int open_obj_pinned(char *path, bool quiet)
126 {
127 	int fd;
128 
129 	fd = bpf_obj_get(path);
130 	if (fd < 0) {
131 		if (!quiet)
132 			p_err("bpf obj get (%s): %s", path,
133 			      errno == EACCES && !is_bpffs(dirname(path)) ?
134 			    "directory not in bpf file system (bpffs)" :
135 			    strerror(errno));
136 		return -1;
137 	}
138 
139 	return fd;
140 }
141 
142 int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
143 {
144 	enum bpf_obj_type type;
145 	int fd;
146 
147 	fd = open_obj_pinned(path, false);
148 	if (fd < 0)
149 		return -1;
150 
151 	type = get_fd_type(fd);
152 	if (type < 0) {
153 		close(fd);
154 		return type;
155 	}
156 	if (type != exp_type) {
157 		p_err("incorrect object type: %s", get_fd_type_name(type));
158 		close(fd);
159 		return -1;
160 	}
161 
162 	return fd;
163 }
164 
165 int mount_bpffs_for_pin(const char *name)
166 {
167 	char err_str[ERR_MAX_LEN];
168 	char *file;
169 	char *dir;
170 	int err = 0;
171 
172 	file = malloc(strlen(name) + 1);
173 	strcpy(file, name);
174 	dir = dirname(file);
175 
176 	if (is_bpffs(dir))
177 		/* nothing to do if already mounted */
178 		goto out_free;
179 
180 	if (block_mount) {
181 		p_err("no BPF file system found, not mounting it due to --nomount option");
182 		err = -1;
183 		goto out_free;
184 	}
185 
186 	err = mnt_fs(dir, "bpf", err_str, ERR_MAX_LEN);
187 	if (err) {
188 		err_str[ERR_MAX_LEN - 1] = '\0';
189 		p_err("can't mount BPF file system to pin the object (%s): %s",
190 		      name, err_str);
191 	}
192 
193 out_free:
194 	free(file);
195 	return err;
196 }
197 
198 int do_pin_fd(int fd, const char *name)
199 {
200 	int err;
201 
202 	err = mount_bpffs_for_pin(name);
203 	if (err)
204 		return err;
205 
206 	return bpf_obj_pin(fd, name);
207 }
208 
209 int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
210 {
211 	unsigned int id;
212 	char *endptr;
213 	int err;
214 	int fd;
215 
216 	if (argc < 3) {
217 		p_err("too few arguments, id ID and FILE path is required");
218 		return -1;
219 	} else if (argc > 3) {
220 		p_err("too many arguments");
221 		return -1;
222 	}
223 
224 	if (!is_prefix(*argv, "id")) {
225 		p_err("expected 'id' got %s", *argv);
226 		return -1;
227 	}
228 	NEXT_ARG();
229 
230 	id = strtoul(*argv, &endptr, 0);
231 	if (*endptr) {
232 		p_err("can't parse %s as ID", *argv);
233 		return -1;
234 	}
235 	NEXT_ARG();
236 
237 	fd = get_fd_by_id(id);
238 	if (fd < 0) {
239 		p_err("can't get prog by id (%u): %s", id, strerror(errno));
240 		return -1;
241 	}
242 
243 	err = do_pin_fd(fd, *argv);
244 
245 	close(fd);
246 	return err;
247 }
248 
249 const char *get_fd_type_name(enum bpf_obj_type type)
250 {
251 	static const char * const names[] = {
252 		[BPF_OBJ_UNKNOWN]	= "unknown",
253 		[BPF_OBJ_PROG]		= "prog",
254 		[BPF_OBJ_MAP]		= "map",
255 	};
256 
257 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
258 		return names[BPF_OBJ_UNKNOWN];
259 
260 	return names[type];
261 }
262 
263 int get_fd_type(int fd)
264 {
265 	char path[PATH_MAX];
266 	char buf[512];
267 	ssize_t n;
268 
269 	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
270 
271 	n = readlink(path, buf, sizeof(buf));
272 	if (n < 0) {
273 		p_err("can't read link type: %s", strerror(errno));
274 		return -1;
275 	}
276 	if (n == sizeof(path)) {
277 		p_err("can't read link type: path too long!");
278 		return -1;
279 	}
280 
281 	if (strstr(buf, "bpf-map"))
282 		return BPF_OBJ_MAP;
283 	else if (strstr(buf, "bpf-prog"))
284 		return BPF_OBJ_PROG;
285 
286 	return BPF_OBJ_UNKNOWN;
287 }
288 
289 char *get_fdinfo(int fd, const char *key)
290 {
291 	char path[PATH_MAX];
292 	char *line = NULL;
293 	size_t line_n = 0;
294 	ssize_t n;
295 	FILE *fdi;
296 
297 	snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
298 
299 	fdi = fopen(path, "r");
300 	if (!fdi) {
301 		p_err("can't open fdinfo: %s", strerror(errno));
302 		return NULL;
303 	}
304 
305 	while ((n = getline(&line, &line_n, fdi)) > 0) {
306 		char *value;
307 		int len;
308 
309 		if (!strstr(line, key))
310 			continue;
311 
312 		fclose(fdi);
313 
314 		value = strchr(line, '\t');
315 		if (!value || !value[1]) {
316 			p_err("malformed fdinfo!?");
317 			free(line);
318 			return NULL;
319 		}
320 		value++;
321 
322 		len = strlen(value);
323 		memmove(line, value, len);
324 		line[len - 1] = '\0';
325 
326 		return line;
327 	}
328 
329 	p_err("key '%s' not found in fdinfo", key);
330 	free(line);
331 	fclose(fdi);
332 	return NULL;
333 }
334 
335 void print_data_json(uint8_t *data, size_t len)
336 {
337 	unsigned int i;
338 
339 	jsonw_start_array(json_wtr);
340 	for (i = 0; i < len; i++)
341 		jsonw_printf(json_wtr, "%d", data[i]);
342 	jsonw_end_array(json_wtr);
343 }
344 
345 void print_hex_data_json(uint8_t *data, size_t len)
346 {
347 	unsigned int i;
348 
349 	jsonw_start_array(json_wtr);
350 	for (i = 0; i < len; i++)
351 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
352 	jsonw_end_array(json_wtr);
353 }
354 
355 int build_pinned_obj_table(struct pinned_obj_table *tab,
356 			   enum bpf_obj_type type)
357 {
358 	struct bpf_prog_info pinned_info = {};
359 	struct pinned_obj *obj_node = NULL;
360 	__u32 len = sizeof(pinned_info);
361 	struct mntent *mntent = NULL;
362 	enum bpf_obj_type objtype;
363 	FILE *mntfile = NULL;
364 	FTSENT *ftse = NULL;
365 	FTS *fts = NULL;
366 	int fd, err;
367 
368 	mntfile = setmntent("/proc/mounts", "r");
369 	if (!mntfile)
370 		return -1;
371 
372 	while ((mntent = getmntent(mntfile))) {
373 		char *path[] = { mntent->mnt_dir, NULL };
374 
375 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
376 			continue;
377 
378 		fts = fts_open(path, 0, NULL);
379 		if (!fts)
380 			continue;
381 
382 		while ((ftse = fts_read(fts))) {
383 			if (!(ftse->fts_info & FTS_F))
384 				continue;
385 			fd = open_obj_pinned(ftse->fts_path, true);
386 			if (fd < 0)
387 				continue;
388 
389 			objtype = get_fd_type(fd);
390 			if (objtype != type) {
391 				close(fd);
392 				continue;
393 			}
394 			memset(&pinned_info, 0, sizeof(pinned_info));
395 			err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
396 			if (err) {
397 				close(fd);
398 				continue;
399 			}
400 
401 			obj_node = malloc(sizeof(*obj_node));
402 			if (!obj_node) {
403 				close(fd);
404 				fts_close(fts);
405 				fclose(mntfile);
406 				return -1;
407 			}
408 
409 			memset(obj_node, 0, sizeof(*obj_node));
410 			obj_node->id = pinned_info.id;
411 			obj_node->path = strdup(ftse->fts_path);
412 			hash_add(tab->table, &obj_node->hash, obj_node->id);
413 
414 			close(fd);
415 		}
416 		fts_close(fts);
417 	}
418 	fclose(mntfile);
419 	return 0;
420 }
421 
422 void delete_pinned_obj_table(struct pinned_obj_table *tab)
423 {
424 	struct pinned_obj *obj;
425 	struct hlist_node *tmp;
426 	unsigned int bkt;
427 
428 	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
429 		hash_del(&obj->hash);
430 		free(obj->path);
431 		free(obj);
432 	}
433 }
434 
435 unsigned int get_page_size(void)
436 {
437 	static int result;
438 
439 	if (!result)
440 		result = getpagesize();
441 	return result;
442 }
443 
444 unsigned int get_possible_cpus(void)
445 {
446 	static unsigned int result;
447 	char buf[128];
448 	long int n;
449 	char *ptr;
450 	int fd;
451 
452 	if (result)
453 		return result;
454 
455 	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
456 	if (fd < 0) {
457 		p_err("can't open sysfs possible cpus");
458 		exit(-1);
459 	}
460 
461 	n = read(fd, buf, sizeof(buf));
462 	if (n < 2) {
463 		p_err("can't read sysfs possible cpus");
464 		exit(-1);
465 	}
466 	close(fd);
467 
468 	if (n == sizeof(buf)) {
469 		p_err("read sysfs possible cpus overflow");
470 		exit(-1);
471 	}
472 
473 	ptr = buf;
474 	n = 0;
475 	while (*ptr && *ptr != '\n') {
476 		unsigned int a, b;
477 
478 		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
479 			n += b - a + 1;
480 
481 			ptr = strchr(ptr, '-') + 1;
482 		} else if (sscanf(ptr, "%u", &a) == 1) {
483 			n++;
484 		} else {
485 			assert(0);
486 		}
487 
488 		while (isdigit(*ptr))
489 			ptr++;
490 		if (*ptr == ',')
491 			ptr++;
492 	}
493 
494 	result = n;
495 
496 	return result;
497 }
498 
499 static char *
500 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
501 {
502 	struct stat st;
503 	int err;
504 
505 	err = stat("/proc/self/ns/net", &st);
506 	if (err) {
507 		p_err("Can't stat /proc/self: %s", strerror(errno));
508 		return NULL;
509 	}
510 
511 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
512 		return NULL;
513 
514 	return if_indextoname(ifindex, buf);
515 }
516 
517 static int read_sysfs_hex_int(char *path)
518 {
519 	char vendor_id_buf[8];
520 	int len;
521 	int fd;
522 
523 	fd = open(path, O_RDONLY);
524 	if (fd < 0) {
525 		p_err("Can't open %s: %s", path, strerror(errno));
526 		return -1;
527 	}
528 
529 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
530 	close(fd);
531 	if (len < 0) {
532 		p_err("Can't read %s: %s", path, strerror(errno));
533 		return -1;
534 	}
535 	if (len >= (int)sizeof(vendor_id_buf)) {
536 		p_err("Value in %s too long", path);
537 		return -1;
538 	}
539 
540 	vendor_id_buf[len] = 0;
541 
542 	return strtol(vendor_id_buf, NULL, 0);
543 }
544 
545 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
546 {
547 	char full_path[64];
548 
549 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
550 		 devname, entry_name);
551 
552 	return read_sysfs_hex_int(full_path);
553 }
554 
555 const char *
556 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
557 		      const char **opt)
558 {
559 	char devname[IF_NAMESIZE];
560 	int vendor_id;
561 	int device_id;
562 
563 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
564 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
565 		      strerror(errno));
566 		return NULL;
567 	}
568 
569 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
570 	if (vendor_id < 0) {
571 		p_err("Can't get device vendor id for %s", devname);
572 		return NULL;
573 	}
574 
575 	switch (vendor_id) {
576 	case 0x19ee:
577 		device_id = read_sysfs_netdev_hex_int(devname, "device");
578 		if (device_id != 0x4000 &&
579 		    device_id != 0x6000 &&
580 		    device_id != 0x6003)
581 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
582 		*opt = "ctx4";
583 		return "NFP-6xxx";
584 	default:
585 		p_err("Can't get bfd arch name for device vendor id 0x%04x",
586 		      vendor_id);
587 		return NULL;
588 	}
589 }
590 
591 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
592 {
593 	char name[IF_NAMESIZE];
594 
595 	if (!ifindex)
596 		return;
597 
598 	printf("  offloaded_to ");
599 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
600 		printf("%s", name);
601 	else
602 		printf("ifindex %u ns_dev %llu ns_ino %llu",
603 		       ifindex, ns_dev, ns_inode);
604 }
605 
606 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
607 {
608 	char name[IF_NAMESIZE];
609 
610 	if (!ifindex)
611 		return;
612 
613 	jsonw_name(json_wtr, "dev");
614 	jsonw_start_object(json_wtr);
615 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
616 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
617 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
618 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
619 		jsonw_string_field(json_wtr, "ifname", name);
620 	jsonw_end_object(json_wtr);
621 }
622 
623 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
624 {
625 	char *endptr;
626 
627 	NEXT_ARGP();
628 
629 	if (*val) {
630 		p_err("%s already specified", what);
631 		return -1;
632 	}
633 
634 	*val = strtoul(**argv, &endptr, 0);
635 	if (*endptr) {
636 		p_err("can't parse %s as %s", **argv, what);
637 		return -1;
638 	}
639 	NEXT_ARGP();
640 
641 	return 0;
642 }
643