xref: /openbmc/linux/tools/bpf/bpftool/common.c (revision a0ae2562c6c4b2721d9fddba63b7286c13517d9f)
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)
134 {
135 	int fd;
136 
137 	fd = bpf_obj_get(path);
138 	if (fd < 0) {
139 		p_err("bpf obj get (%s): %s", path,
140 		      errno == EACCES && !is_bpffs(dirname(path)) ?
141 		    "directory not in bpf file system (bpffs)" :
142 		    strerror(errno));
143 		return -1;
144 	}
145 
146 	return fd;
147 }
148 
149 int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
150 {
151 	enum bpf_obj_type type;
152 	int fd;
153 
154 	fd = open_obj_pinned(path);
155 	if (fd < 0)
156 		return -1;
157 
158 	type = get_fd_type(fd);
159 	if (type < 0) {
160 		close(fd);
161 		return type;
162 	}
163 	if (type != exp_type) {
164 		p_err("incorrect object type: %s", get_fd_type_name(type));
165 		close(fd);
166 		return -1;
167 	}
168 
169 	return fd;
170 }
171 
172 int do_pin_fd(int fd, const char *name)
173 {
174 	char err_str[ERR_MAX_LEN];
175 	char *file;
176 	char *dir;
177 	int err = 0;
178 
179 	err = bpf_obj_pin(fd, name);
180 	if (!err)
181 		goto out;
182 
183 	file = malloc(strlen(name) + 1);
184 	strcpy(file, name);
185 	dir = dirname(file);
186 
187 	if (errno != EPERM || is_bpffs(dir)) {
188 		p_err("can't pin the object (%s): %s", name, strerror(errno));
189 		goto out_free;
190 	}
191 
192 	/* Attempt to mount bpffs, then retry pinning. */
193 	err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
194 	if (!err) {
195 		err = bpf_obj_pin(fd, name);
196 		if (err)
197 			p_err("can't pin the object (%s): %s", name,
198 			      strerror(errno));
199 	} else {
200 		err_str[ERR_MAX_LEN - 1] = '\0';
201 		p_err("can't mount BPF file system to pin the object (%s): %s",
202 		      name, err_str);
203 	}
204 
205 out_free:
206 	free(file);
207 out:
208 	return err;
209 }
210 
211 int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
212 {
213 	unsigned int id;
214 	char *endptr;
215 	int err;
216 	int fd;
217 
218 	if (!is_prefix(*argv, "id")) {
219 		p_err("expected 'id' got %s", *argv);
220 		return -1;
221 	}
222 	NEXT_ARG();
223 
224 	id = strtoul(*argv, &endptr, 0);
225 	if (*endptr) {
226 		p_err("can't parse %s as ID", *argv);
227 		return -1;
228 	}
229 	NEXT_ARG();
230 
231 	if (argc != 1)
232 		usage();
233 
234 	fd = get_fd_by_id(id);
235 	if (fd < 0) {
236 		p_err("can't get prog by id (%u): %s", id, strerror(errno));
237 		return -1;
238 	}
239 
240 	err = do_pin_fd(fd, *argv);
241 
242 	close(fd);
243 	return err;
244 }
245 
246 const char *get_fd_type_name(enum bpf_obj_type type)
247 {
248 	static const char * const names[] = {
249 		[BPF_OBJ_UNKNOWN]	= "unknown",
250 		[BPF_OBJ_PROG]		= "prog",
251 		[BPF_OBJ_MAP]		= "map",
252 	};
253 
254 	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
255 		return names[BPF_OBJ_UNKNOWN];
256 
257 	return names[type];
258 }
259 
260 int get_fd_type(int fd)
261 {
262 	char path[PATH_MAX];
263 	char buf[512];
264 	ssize_t n;
265 
266 	snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
267 
268 	n = readlink(path, buf, sizeof(buf));
269 	if (n < 0) {
270 		p_err("can't read link type: %s", strerror(errno));
271 		return -1;
272 	}
273 	if (n == sizeof(path)) {
274 		p_err("can't read link type: path too long!");
275 		return -1;
276 	}
277 
278 	if (strstr(buf, "bpf-map"))
279 		return BPF_OBJ_MAP;
280 	else if (strstr(buf, "bpf-prog"))
281 		return BPF_OBJ_PROG;
282 
283 	return BPF_OBJ_UNKNOWN;
284 }
285 
286 char *get_fdinfo(int fd, const char *key)
287 {
288 	char path[PATH_MAX];
289 	char *line = NULL;
290 	size_t line_n = 0;
291 	ssize_t n;
292 	FILE *fdi;
293 
294 	snprintf(path, sizeof(path), "/proc/%d/fdinfo/%d", getpid(), fd);
295 
296 	fdi = fopen(path, "r");
297 	if (!fdi) {
298 		p_err("can't open fdinfo: %s", strerror(errno));
299 		return NULL;
300 	}
301 
302 	while ((n = getline(&line, &line_n, fdi))) {
303 		char *value;
304 		int len;
305 
306 		if (!strstr(line, key))
307 			continue;
308 
309 		fclose(fdi);
310 
311 		value = strchr(line, '\t');
312 		if (!value || !value[1]) {
313 			p_err("malformed fdinfo!?");
314 			free(line);
315 			return NULL;
316 		}
317 		value++;
318 
319 		len = strlen(value);
320 		memmove(line, value, len);
321 		line[len - 1] = '\0';
322 
323 		return line;
324 	}
325 
326 	p_err("key '%s' not found in fdinfo", key);
327 	free(line);
328 	fclose(fdi);
329 	return NULL;
330 }
331 
332 void print_data_json(uint8_t *data, size_t len)
333 {
334 	unsigned int i;
335 
336 	jsonw_start_array(json_wtr);
337 	for (i = 0; i < len; i++)
338 		jsonw_printf(json_wtr, "%d", data[i]);
339 	jsonw_end_array(json_wtr);
340 }
341 
342 void print_hex_data_json(uint8_t *data, size_t len)
343 {
344 	unsigned int i;
345 
346 	jsonw_start_array(json_wtr);
347 	for (i = 0; i < len; i++)
348 		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
349 	jsonw_end_array(json_wtr);
350 }
351 
352 int build_pinned_obj_table(struct pinned_obj_table *tab,
353 			   enum bpf_obj_type type)
354 {
355 	struct bpf_prog_info pinned_info = {};
356 	struct pinned_obj *obj_node = NULL;
357 	__u32 len = sizeof(pinned_info);
358 	struct mntent *mntent = NULL;
359 	enum bpf_obj_type objtype;
360 	FILE *mntfile = NULL;
361 	FTSENT *ftse = NULL;
362 	FTS *fts = NULL;
363 	int fd, err;
364 
365 	mntfile = setmntent("/proc/mounts", "r");
366 	if (!mntfile)
367 		return -1;
368 
369 	while ((mntent = getmntent(mntfile))) {
370 		char *path[] = { mntent->mnt_dir, NULL };
371 
372 		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
373 			continue;
374 
375 		fts = fts_open(path, 0, NULL);
376 		if (!fts)
377 			continue;
378 
379 		while ((ftse = fts_read(fts))) {
380 			if (!(ftse->fts_info & FTS_F))
381 				continue;
382 			fd = open_obj_pinned(ftse->fts_path);
383 			if (fd < 0)
384 				continue;
385 
386 			objtype = get_fd_type(fd);
387 			if (objtype != type) {
388 				close(fd);
389 				continue;
390 			}
391 			memset(&pinned_info, 0, sizeof(pinned_info));
392 			err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
393 			if (err) {
394 				close(fd);
395 				continue;
396 			}
397 
398 			obj_node = malloc(sizeof(*obj_node));
399 			if (!obj_node) {
400 				close(fd);
401 				fts_close(fts);
402 				fclose(mntfile);
403 				return -1;
404 			}
405 
406 			memset(obj_node, 0, sizeof(*obj_node));
407 			obj_node->id = pinned_info.id;
408 			obj_node->path = strdup(ftse->fts_path);
409 			hash_add(tab->table, &obj_node->hash, obj_node->id);
410 
411 			close(fd);
412 		}
413 		fts_close(fts);
414 	}
415 	fclose(mntfile);
416 	return 0;
417 }
418 
419 void delete_pinned_obj_table(struct pinned_obj_table *tab)
420 {
421 	struct pinned_obj *obj;
422 	struct hlist_node *tmp;
423 	unsigned int bkt;
424 
425 	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
426 		hash_del(&obj->hash);
427 		free(obj->path);
428 		free(obj);
429 	}
430 }
431 
432 unsigned int get_page_size(void)
433 {
434 	static int result;
435 
436 	if (!result)
437 		result = getpagesize();
438 	return result;
439 }
440 
441 unsigned int get_possible_cpus(void)
442 {
443 	static unsigned int result;
444 	char buf[128];
445 	long int n;
446 	char *ptr;
447 	int fd;
448 
449 	if (result)
450 		return result;
451 
452 	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
453 	if (fd < 0) {
454 		p_err("can't open sysfs possible cpus");
455 		exit(-1);
456 	}
457 
458 	n = read(fd, buf, sizeof(buf));
459 	if (n < 2) {
460 		p_err("can't read sysfs possible cpus");
461 		exit(-1);
462 	}
463 	close(fd);
464 
465 	if (n == sizeof(buf)) {
466 		p_err("read sysfs possible cpus overflow");
467 		exit(-1);
468 	}
469 
470 	ptr = buf;
471 	n = 0;
472 	while (*ptr && *ptr != '\n') {
473 		unsigned int a, b;
474 
475 		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
476 			n += b - a + 1;
477 
478 			ptr = strchr(ptr, '-') + 1;
479 		} else if (sscanf(ptr, "%u", &a) == 1) {
480 			n++;
481 		} else {
482 			assert(0);
483 		}
484 
485 		while (isdigit(*ptr))
486 			ptr++;
487 		if (*ptr == ',')
488 			ptr++;
489 	}
490 
491 	result = n;
492 
493 	return result;
494 }
495 
496 static char *
497 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
498 {
499 	struct stat st;
500 	int err;
501 
502 	err = stat("/proc/self/ns/net", &st);
503 	if (err) {
504 		p_err("Can't stat /proc/self: %s", strerror(errno));
505 		return NULL;
506 	}
507 
508 	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
509 		return NULL;
510 
511 	return if_indextoname(ifindex, buf);
512 }
513 
514 static int read_sysfs_hex_int(char *path)
515 {
516 	char vendor_id_buf[8];
517 	int len;
518 	int fd;
519 
520 	fd = open(path, O_RDONLY);
521 	if (fd < 0) {
522 		p_err("Can't open %s: %s", path, strerror(errno));
523 		return -1;
524 	}
525 
526 	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
527 	close(fd);
528 	if (len < 0) {
529 		p_err("Can't read %s: %s", path, strerror(errno));
530 		return -1;
531 	}
532 	if (len >= (int)sizeof(vendor_id_buf)) {
533 		p_err("Value in %s too long", path);
534 		return -1;
535 	}
536 
537 	vendor_id_buf[len] = 0;
538 
539 	return strtol(vendor_id_buf, NULL, 0);
540 }
541 
542 static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
543 {
544 	char full_path[64];
545 
546 	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
547 		 devname, entry_name);
548 
549 	return read_sysfs_hex_int(full_path);
550 }
551 
552 const char *ifindex_to_bfd_name_ns(__u32 ifindex, __u64 ns_dev, __u64 ns_ino)
553 {
554 	char devname[IF_NAMESIZE];
555 	int vendor_id;
556 	int device_id;
557 
558 	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
559 		p_err("Can't get net device name for ifindex %d: %s", ifindex,
560 		      strerror(errno));
561 		return NULL;
562 	}
563 
564 	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
565 	if (vendor_id < 0) {
566 		p_err("Can't get device vendor id for %s", devname);
567 		return NULL;
568 	}
569 
570 	switch (vendor_id) {
571 	case 0x19ee:
572 		device_id = read_sysfs_netdev_hex_int(devname, "device");
573 		if (device_id != 0x4000 &&
574 		    device_id != 0x6000 &&
575 		    device_id != 0x6003)
576 			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
577 		return "NFP-6xxx";
578 	default:
579 		p_err("Can't get bfd arch name for device vendor id 0x%04x",
580 		      vendor_id);
581 		return NULL;
582 	}
583 }
584 
585 void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
586 {
587 	char name[IF_NAMESIZE];
588 
589 	if (!ifindex)
590 		return;
591 
592 	printf(" dev ");
593 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
594 		printf("%s", name);
595 	else
596 		printf("ifindex %u ns_dev %llu ns_ino %llu",
597 		       ifindex, ns_dev, ns_inode);
598 }
599 
600 void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
601 {
602 	char name[IF_NAMESIZE];
603 
604 	if (!ifindex)
605 		return;
606 
607 	jsonw_name(json_wtr, "dev");
608 	jsonw_start_object(json_wtr);
609 	jsonw_uint_field(json_wtr, "ifindex", ifindex);
610 	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
611 	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
612 	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
613 		jsonw_string_field(json_wtr, "ifname", name);
614 	jsonw_end_object(json_wtr);
615 }
616