xref: /openbmc/linux/tools/bpf/bpftool/common.c (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1)
1 /*
2  * Copyright (C) 2017-2018 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 #include <ctype.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <fts.h>
38 #include <libgen.h>
39 #include <mntent.h>
40 #include <stdbool.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <linux/limits.h>
46 #include <linux/magic.h>
47 #include <net/if.h>
48 #include <sys/mount.h>
49 #include <sys/stat.h>
50 #include <sys/types.h>
51 #include <sys/vfs.h>
52 
53 #include <bpf.h>
54 
55 #include "main.h"
56 
57 #ifndef BPF_FS_MAGIC
58 #define BPF_FS_MAGIC		0xcafe4a11
59 #endif
60 
61 void p_err(const char *fmt, ...)
62 {
63 	va_list ap;
64 
65 	va_start(ap, fmt);
66 	if (json_output) {
67 		jsonw_start_object(json_wtr);
68 		jsonw_name(json_wtr, "error");
69 		jsonw_vprintf_enquote(json_wtr, fmt, ap);
70 		jsonw_end_object(json_wtr);
71 	} else {
72 		fprintf(stderr, "Error: ");
73 		vfprintf(stderr, fmt, ap);
74 		fprintf(stderr, "\n");
75 	}
76 	va_end(ap);
77 }
78 
79 void p_info(const char *fmt, ...)
80 {
81 	va_list ap;
82 
83 	if (json_output)
84 		return;
85 
86 	va_start(ap, fmt);
87 	vfprintf(stderr, fmt, ap);
88 	fprintf(stderr, "\n");
89 	va_end(ap);
90 }
91 
92 static bool is_bpffs(char *path)
93 {
94 	struct statfs st_fs;
95 
96 	if (statfs(path, &st_fs) < 0)
97 		return false;
98 
99 	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
100 }
101 
102 static int mnt_bpffs(const char *target, char *buff, size_t bufflen)
103 {
104 	bool bind_done = false;
105 
106 	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
107 		if (errno != EINVAL || bind_done) {
108 			snprintf(buff, bufflen,
109 				 "mount --make-private %s failed: %s",
110 				 target, strerror(errno));
111 			return -1;
112 		}
113 
114 		if (mount(target, target, "none", MS_BIND, NULL)) {
115 			snprintf(buff, bufflen,
116 				 "mount --bind %s %s failed: %s",
117 				 target, target, strerror(errno));
118 			return -1;
119 		}
120 
121 		bind_done = true;
122 	}
123 
124 	if (mount("bpf", target, "bpf", 0, "mode=0700")) {
125 		snprintf(buff, bufflen, "mount -t bpf bpf %s failed: %s",
126 			 target, strerror(errno));
127 		return -1;
128 	}
129 
130 	return 0;
131 }
132 
133 int open_obj_pinned(char *path, bool quiet)
134 {
135 	int fd;
136 
137 	fd = bpf_obj_get(path);
138 	if (fd < 0) {
139 		if (!quiet)
140 			p_err("bpf obj get (%s): %s", path,
141 			      errno == EACCES && !is_bpffs(dirname(path)) ?
142 			    "directory not in bpf file system (bpffs)" :
143 			    strerror(errno));
144 		return -1;
145 	}
146 
147 	return fd;
148 }
149 
150 int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
151 {
152 	enum bpf_obj_type type;
153 	int fd;
154 
155 	fd = open_obj_pinned(path, false);
156 	if (fd < 0)
157 		return -1;
158 
159 	type = get_fd_type(fd);
160 	if (type < 0) {
161 		close(fd);
162 		return type;
163 	}
164 	if (type != exp_type) {
165 		p_err("incorrect object type: %s", get_fd_type_name(type));
166 		close(fd);
167 		return -1;
168 	}
169 
170 	return fd;
171 }
172 
173 int do_pin_fd(int fd, const char *name)
174 {
175 	char err_str[ERR_MAX_LEN];
176 	char *file;
177 	char *dir;
178 	int err = 0;
179 
180 	err = bpf_obj_pin(fd, name);
181 	if (!err)
182 		goto out;
183 
184 	file = malloc(strlen(name) + 1);
185 	strcpy(file, name);
186 	dir = dirname(file);
187 
188 	if (errno != EPERM || is_bpffs(dir)) {
189 		p_err("can't pin the object (%s): %s", name, strerror(errno));
190 		goto out_free;
191 	}
192 
193 	/* Attempt to mount bpffs, then retry pinning. */
194 	err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
195 	if (!err) {
196 		err = bpf_obj_pin(fd, name);
197 		if (err)
198 			p_err("can't pin the object (%s): %s", name,
199 			      strerror(errno));
200 	} else {
201 		err_str[ERR_MAX_LEN - 1] = '\0';
202 		p_err("can't mount BPF file system to pin the object (%s): %s",
203 		      name, err_str);
204 	}
205 
206 out_free:
207 	free(file);
208 out:
209 	return err;
210 }
211 
212 int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
213 {
214 	unsigned int id;
215 	char *endptr;
216 	int err;
217 	int fd;
218 
219 	if (argc < 3) {
220 		p_err("too few arguments, id ID and FILE path is required");
221 		return -1;
222 	} else if (argc > 3) {
223 		p_err("too many arguments");
224 		return -1;
225 	}
226 
227 	if (!is_prefix(*argv, "id")) {
228 		p_err("expected 'id' got %s", *argv);
229 		return -1;
230 	}
231 	NEXT_ARG();
232 
233 	id = strtoul(*argv, &endptr, 0);
234 	if (*endptr) {
235 		p_err("can't parse %s as ID", *argv);
236 		return -1;
237 	}
238 	NEXT_ARG();
239 
240 	fd = get_fd_by_id(id);
241 	if (fd < 0) {
242 		p_err("can't get prog by id (%u): %s", id, strerror(errno));
243 		return -1;
244 	}
245 
246 	err = do_pin_fd(fd, *argv);
247 
248 	close(fd);
249 	return err;
250 }
251 
252 const char *get_fd_type_name(enum bpf_obj_type type)
253 {
254 	static const char * const names[] = {
255 		[BPF_OBJ_UNKNOWN]	= "unknown",
256 		[BPF_OBJ_PROG]		= "prog",
257 		[BPF_OBJ_MAP]		= "map",
258 	};
259 
260 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
261 		return names[BPF_OBJ_UNKNOWN];
262 
263 	return names[type];
264 }
265 
266 int get_fd_type(int fd)
267 {
268 	char path[PATH_MAX];
269 	char buf[512];
270 	ssize_t n;
271 
272 	snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
273 
274 	n = readlink(path, buf, sizeof(buf));
275 	if (n < 0) {
276 		p_err("can't read link type: %s", strerror(errno));
277 		return -1;
278 	}
279 	if (n == sizeof(path)) {
280 		p_err("can't read link type: path too long!");
281 		return -1;
282 	}
283 
284 	if (strstr(buf, "bpf-map"))
285 		return BPF_OBJ_MAP;
286 	else if (strstr(buf, "bpf-prog"))
287 		return BPF_OBJ_PROG;
288 
289 	return BPF_OBJ_UNKNOWN;
290 }
291 
292 char *get_fdinfo(int fd, const char *key)
293 {
294 	char path[PATH_MAX];
295 	char *line = NULL;
296 	size_t line_n = 0;
297 	ssize_t n;
298 	FILE *fdi;
299 
300 	snprintf(path, sizeof(path), "/proc/%d/fdinfo/%d", getpid(), fd);
301 
302 	fdi = fopen(path, "r");
303 	if (!fdi) {
304 		p_err("can't open fdinfo: %s", strerror(errno));
305 		return NULL;
306 	}
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 			p_err("malformed fdinfo!?");
320 			free(line);
321 			return NULL;
322 		}
323 		value++;
324 
325 		len = strlen(value);
326 		memmove(line, value, len);
327 		line[len - 1] = '\0';
328 
329 		return line;
330 	}
331 
332 	p_err("key '%s' not found in fdinfo", key);
333 	free(line);
334 	fclose(fdi);
335 	return NULL;
336 }
337 
338 void print_data_json(uint8_t *data, size_t len)
339 {
340 	unsigned int i;
341 
342 	jsonw_start_array(json_wtr);
343 	for (i = 0; i < len; i++)
344 		jsonw_printf(json_wtr, "%d", data[i]);
345 	jsonw_end_array(json_wtr);
346 }
347 
348 void print_hex_data_json(uint8_t *data, size_t len)
349 {
350 	unsigned int i;
351 
352 	jsonw_start_array(json_wtr);
353 	for (i = 0; i < len; i++)
354 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
355 	jsonw_end_array(json_wtr);
356 }
357 
358 int build_pinned_obj_table(struct pinned_obj_table *tab,
359 			   enum bpf_obj_type type)
360 {
361 	struct bpf_prog_info pinned_info = {};
362 	struct pinned_obj *obj_node = NULL;
363 	__u32 len = sizeof(pinned_info);
364 	struct mntent *mntent = NULL;
365 	enum bpf_obj_type objtype;
366 	FILE *mntfile = NULL;
367 	FTSENT *ftse = NULL;
368 	FTS *fts = NULL;
369 	int fd, err;
370 
371 	mntfile = setmntent("/proc/mounts", "r");
372 	if (!mntfile)
373 		return -1;
374 
375 	while ((mntent = getmntent(mntfile))) {
376 		char *path[] = { mntent->mnt_dir, NULL };
377 
378 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
379 			continue;
380 
381 		fts = fts_open(path, 0, NULL);
382 		if (!fts)
383 			continue;
384 
385 		while ((ftse = fts_read(fts))) {
386 			if (!(ftse->fts_info & FTS_F))
387 				continue;
388 			fd = open_obj_pinned(ftse->fts_path, true);
389 			if (fd < 0)
390 				continue;
391 
392 			objtype = get_fd_type(fd);
393 			if (objtype != type) {
394 				close(fd);
395 				continue;
396 			}
397 			memset(&pinned_info, 0, sizeof(pinned_info));
398 			err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
399 			if (err) {
400 				close(fd);
401 				continue;
402 			}
403 
404 			obj_node = malloc(sizeof(*obj_node));
405 			if (!obj_node) {
406 				close(fd);
407 				fts_close(fts);
408 				fclose(mntfile);
409 				return -1;
410 			}
411 
412 			memset(obj_node, 0, sizeof(*obj_node));
413 			obj_node->id = pinned_info.id;
414 			obj_node->path = strdup(ftse->fts_path);
415 			hash_add(tab->table, &obj_node->hash, obj_node->id);
416 
417 			close(fd);
418 		}
419 		fts_close(fts);
420 	}
421 	fclose(mntfile);
422 	return 0;
423 }
424 
425 void delete_pinned_obj_table(struct pinned_obj_table *tab)
426 {
427 	struct pinned_obj *obj;
428 	struct hlist_node *tmp;
429 	unsigned int bkt;
430 
431 	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
432 		hash_del(&obj->hash);
433 		free(obj->path);
434 		free(obj);
435 	}
436 }
437 
438 unsigned int get_page_size(void)
439 {
440 	static int result;
441 
442 	if (!result)
443 		result = getpagesize();
444 	return result;
445 }
446 
447 unsigned int get_possible_cpus(void)
448 {
449 	static unsigned int result;
450 	char buf[128];
451 	long int n;
452 	char *ptr;
453 	int fd;
454 
455 	if (result)
456 		return result;
457 
458 	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
459 	if (fd < 0) {
460 		p_err("can't open sysfs possible cpus");
461 		exit(-1);
462 	}
463 
464 	n = read(fd, buf, sizeof(buf));
465 	if (n < 2) {
466 		p_err("can't read sysfs possible cpus");
467 		exit(-1);
468 	}
469 	close(fd);
470 
471 	if (n == sizeof(buf)) {
472 		p_err("read sysfs possible cpus overflow");
473 		exit(-1);
474 	}
475 
476 	ptr = buf;
477 	n = 0;
478 	while (*ptr && *ptr != '\n') {
479 		unsigned int a, b;
480 
481 		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
482 			n += b - a + 1;
483 
484 			ptr = strchr(ptr, '-') + 1;
485 		} else if (sscanf(ptr, "%u", &a) == 1) {
486 			n++;
487 		} else {
488 			assert(0);
489 		}
490 
491 		while (isdigit(*ptr))
492 			ptr++;
493 		if (*ptr == ',')
494 			ptr++;
495 	}
496 
497 	result = n;
498 
499 	return result;
500 }
501 
502 static char *
503 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
504 {
505 	struct stat st;
506 	int err;
507 
508 	err = stat("/proc/self/ns/net", &st);
509 	if (err) {
510 		p_err("Can't stat /proc/self: %s", strerror(errno));
511 		return NULL;
512 	}
513 
514 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
515 		return NULL;
516 
517 	return if_indextoname(ifindex, buf);
518 }
519 
520 static int read_sysfs_hex_int(char *path)
521 {
522 	char vendor_id_buf[8];
523 	int len;
524 	int fd;
525 
526 	fd = open(path, O_RDONLY);
527 	if (fd < 0) {
528 		p_err("Can't open %s: %s", path, strerror(errno));
529 		return -1;
530 	}
531 
532 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
533 	close(fd);
534 	if (len < 0) {
535 		p_err("Can't read %s: %s", path, strerror(errno));
536 		return -1;
537 	}
538 	if (len >= (int)sizeof(vendor_id_buf)) {
539 		p_err("Value in %s too long", path);
540 		return -1;
541 	}
542 
543 	vendor_id_buf[len] = 0;
544 
545 	return strtol(vendor_id_buf, NULL, 0);
546 }
547 
548 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
549 {
550 	char full_path[64];
551 
552 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
553 		 devname, entry_name);
554 
555 	return read_sysfs_hex_int(full_path);
556 }
557 
558 const char *
559 ifindex_to_bfd_params(__u32 ifindex, __u64 ns_dev, __u64 ns_ino,
560 		      const char **opt)
561 {
562 	char devname[IF_NAMESIZE];
563 	int vendor_id;
564 	int device_id;
565 
566 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
567 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
568 		      strerror(errno));
569 		return NULL;
570 	}
571 
572 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
573 	if (vendor_id < 0) {
574 		p_err("Can't get device vendor id for %s", devname);
575 		return NULL;
576 	}
577 
578 	switch (vendor_id) {
579 	case 0x19ee:
580 		device_id = read_sysfs_netdev_hex_int(devname, "device");
581 		if (device_id != 0x4000 &&
582 		    device_id != 0x6000 &&
583 		    device_id != 0x6003)
584 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
585 		*opt = "ctx4";
586 		return "NFP-6xxx";
587 	default:
588 		p_err("Can't get bfd arch name for device vendor id 0x%04x",
589 		      vendor_id);
590 		return NULL;
591 	}
592 }
593 
594 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
595 {
596 	char name[IF_NAMESIZE];
597 
598 	if (!ifindex)
599 		return;
600 
601 	printf(" dev ");
602 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
603 		printf("%s", name);
604 	else
605 		printf("ifindex %u ns_dev %llu ns_ino %llu",
606 		       ifindex, ns_dev, ns_inode);
607 }
608 
609 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
610 {
611 	char name[IF_NAMESIZE];
612 
613 	if (!ifindex)
614 		return;
615 
616 	jsonw_name(json_wtr, "dev");
617 	jsonw_start_object(json_wtr);
618 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
619 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
620 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
621 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
622 		jsonw_string_field(json_wtr, "ifname", name);
623 	jsonw_end_object(json_wtr);
624 }
625 
626 int parse_u32_arg(int *argc, char ***argv, __u32 *val, const char *what)
627 {
628 	char *endptr;
629 
630 	NEXT_ARGP();
631 
632 	if (*val) {
633 		p_err("%s already specified", what);
634 		return -1;
635 	}
636 
637 	*val = strtoul(**argv, &endptr, 0);
638 	if (*endptr) {
639 		p_err("can't parse %s as %s", **argv, what);
640 		return -1;
641 	}
642 	NEXT_ARGP();
643 
644 	return 0;
645 }
646