summaryrefslogtreecommitdiffstats
path: root/tools/bpf/bpftool/common.c
blob: 0b482c0070e04fb06b65eb503959afc06170b472 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
/*
 * Copyright (C) 2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/* Author: Jakub Kicinski <kubakici@wp.pl> */

#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <libgen.h>
#include <mntent.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <linux/limits.h>
#include <linux/magic.h>
#include <net/if.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/vfs.h>

#include <bpf.h>

#include "main.h"

void p_err(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	if (json_output) {
		jsonw_start_object(json_wtr);
		jsonw_name(json_wtr, "error");
		jsonw_vprintf_enquote(json_wtr, fmt, ap);
		jsonw_end_object(json_wtr);
	} else {
		fprintf(stderr, "Error: ");
		vfprintf(stderr, fmt, ap);
		fprintf(stderr, "\n");
	}
	va_end(ap);
}

void p_info(const char *fmt, ...)
{
	va_list ap;

	if (json_output)
		return;

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n");
	va_end(ap);
}

static bool is_bpffs(char *path)
{
	struct statfs st_fs;

	if (statfs(path, &st_fs) < 0)
		return false;

	return (unsigned long)st_fs.f_type == BPF_FS_MAGIC;
}

static int mnt_bpffs(const char *target, char *buff, size_t bufflen)
{
	bool bind_done = false;

	while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) {
		if (errno != EINVAL || bind_done) {
			snprintf(buff, bufflen,
				 "mount --make-private %s failed: %s",
				 target, strerror(errno));
			return -1;
		}

		if (mount(target, target, "none", MS_BIND, NULL)) {
			snprintf(buff, bufflen,
				 "mount --bind %s %s failed: %s",
				 target, target, strerror(errno));
			return -1;
		}

		bind_done = true;
	}

	if (mount("bpf", target, "bpf", 0, "mode=0700")) {
		snprintf(buff, bufflen, "mount -t bpf bpf %s failed: %s",
			 target, strerror(errno));
		return -1;
	}

	return 0;
}

int open_obj_pinned(char *path)
{
	int fd;

	fd = bpf_obj_get(path);
	if (fd < 0) {
		p_err("bpf obj get (%s): %s", path,
		      errno == EACCES && !is_bpffs(dirname(path)) ?
		    "directory not in bpf file system (bpffs)" :
		    strerror(errno));
		return -1;
	}

	return fd;
}

int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type)
{
	enum bpf_obj_type type;
	int fd;

	fd = open_obj_pinned(path);
	if (fd < 0)
		return -1;

	type = get_fd_type(fd);
	if (type < 0) {
		close(fd);
		return type;
	}
	if (type != exp_type) {
		p_err("incorrect object type: %s", get_fd_type_name(type));
		close(fd);
		return -1;
	}

	return fd;
}

int do_pin_fd(int fd, const char *name)
{
	char err_str[ERR_MAX_LEN];
	char *file;
	char *dir;
	int err = 0;

	err = bpf_obj_pin(fd, name);
	if (!err)
		goto out;

	file = malloc(strlen(name) + 1);
	strcpy(file, name);
	dir = dirname(file);

	if (errno != EPERM || is_bpffs(dir)) {
		p_err("can't pin the object (%s): %s", name, strerror(errno));
		goto out_free;
	}

	/* Attempt to mount bpffs, then retry pinning. */
	err = mnt_bpffs(dir, err_str, ERR_MAX_LEN);
	if (!err) {
		err = bpf_obj_pin(fd, name);
		if (err)
			p_err("can't pin the object (%s): %s", name,
			      strerror(errno));
	} else {
		err_str[ERR_MAX_LEN - 1] = '\0';
		p_err("can't mount BPF file system to pin the object (%s): %s",
		      name, err_str);
	}

out_free:
	free(file);
out:
	return err;
}

int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32))
{
	unsigned int id;
	char *endptr;
	int err;
	int fd;

	if (!is_prefix(*argv, "id")) {
		p_err("expected 'id' got %s", *argv);
		return -1;
	}
	NEXT_ARG();

	id = strtoul(*argv, &endptr, 0);
	if (*endptr) {
		p_err("can't parse %s as ID", *argv);
		return -1;
	}
	NEXT_ARG();

	if (argc != 1)
		usage();

	fd = get_fd_by_id(id);
	if (fd < 0) {
		p_err("can't get prog by id (%u): %s", id, strerror(errno));
		return -1;
	}

	err = do_pin_fd(fd, *argv);

	close(fd);
	return err;
}

const char *get_fd_type_name(enum bpf_obj_type type)
{
	static const char * const names[] = {
		[BPF_OBJ_UNKNOWN]	= "unknown",
		[BPF_OBJ_PROG]		= "prog",
		[BPF_OBJ_MAP]		= "map",
	};

	if (type < 0 || type >= ARRAY_SIZE(names) || !names[type])
		return names[BPF_OBJ_UNKNOWN];

	return names[type];
}

int get_fd_type(int fd)
{
	char path[PATH_MAX];
	char buf[512];
	ssize_t n;

	snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);

	n = readlink(path, buf, sizeof(buf));
	if (n < 0) {
		p_err("can't read link type: %s", strerror(errno));
		return -1;
	}
	if (n == sizeof(path)) {
		p_err("can't read link type: path too long!");
		return -1;
	}

	if (strstr(buf, "bpf-map"))
		return BPF_OBJ_MAP;
	else if (strstr(buf, "bpf-prog"))
		return BPF_OBJ_PROG;

	return BPF_OBJ_UNKNOWN;
}

char *get_fdinfo(int fd, const char *key)
{
	char path[PATH_MAX];
	char *line = NULL;
	size_t line_n = 0;
	ssize_t n;
	FILE *fdi;

	snprintf(path, sizeof(path), "/proc/%d/fdinfo/%d", getpid(), fd);

	fdi = fopen(path, "r");
	if (!fdi) {
		p_err("can't open fdinfo: %s", strerror(errno));
		return NULL;
	}

	while ((n = getline(&line, &line_n, fdi))) {
		char *value;
		int len;

		if (!strstr(line, key))
			continue;

		fclose(fdi);

		value = strchr(line, '\t');
		if (!value || !value[1]) {
			p_err("malformed fdinfo!?");
			free(line);
			return NULL;
		}
		value++;

		len = strlen(value);
		memmove(line, value, len);
		line[len - 1] = '\0';

		return line;
	}

	p_err("key '%s' not found in fdinfo", key);
	free(line);
	fclose(fdi);
	return NULL;
}

void print_hex_data_json(uint8_t *data, size_t len)
{
	unsigned int i;

	jsonw_start_array(json_wtr);
	for (i = 0; i < len; i++)
		jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]);
	jsonw_end_array(json_wtr);
}

int build_pinned_obj_table(struct pinned_obj_table *tab,
			   enum bpf_obj_type type)
{
	struct bpf_prog_info pinned_info = {};
	struct pinned_obj *obj_node = NULL;
	__u32 len = sizeof(pinned_info);
	struct mntent *mntent = NULL;
	enum bpf_obj_type objtype;
	FILE *mntfile = NULL;
	FTSENT *ftse = NULL;
	FTS *fts = NULL;
	int fd, err;

	mntfile = setmntent("/proc/mounts", "r");
	if (!mntfile)
		return -1;

	while ((mntent = getmntent(mntfile))) {
		char *path[] = { mntent->mnt_dir, NULL };

		if (strncmp(mntent->mnt_type, "bpf", 3) != 0)
			continue;

		fts = fts_open(path, 0, NULL);
		if (!fts)
			continue;

		while ((ftse = fts_read(fts))) {
			if (!(ftse->fts_info & FTS_F))
				continue;
			fd = open_obj_pinned(ftse->fts_path);
			if (fd < 0)
				continue;

			objtype = get_fd_type(fd);
			if (objtype != type) {
				close(fd);
				continue;
			}
			memset(&pinned_info, 0, sizeof(pinned_info));
			err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len);
			if (err) {
				close(fd);
				continue;
			}

			obj_node = malloc(sizeof(*obj_node));
			if (!obj_node) {
				close(fd);
				fts_close(fts);
				fclose(mntfile);
				return -1;
			}

			memset(obj_node, 0, sizeof(*obj_node));
			obj_node->id = pinned_info.id;
			obj_node->path = strdup(ftse->fts_path);
			hash_add(tab->table, &obj_node->hash, obj_node->id);

			close(fd);
		}
		fts_close(fts);
	}
	fclose(mntfile);
	return 0;
}

void delete_pinned_obj_table(struct pinned_obj_table *tab)
{
	struct pinned_obj *obj;
	struct hlist_node *tmp;
	unsigned int bkt;

	hash_for_each_safe(tab->table, bkt, tmp, obj, hash) {
		hash_del(&obj->hash);
		free(obj->path);
		free(obj);
	}
}

static char *
ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
{
	struct stat st;
	int err;

	err = stat("/proc/self/ns/net", &st);
	if (err) {
		p_err("Can't stat /proc/self: %s", strerror(errno));
		return NULL;
	}

	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
		return NULL;

	return if_indextoname(ifindex, buf);
}

static int read_sysfs_hex_int(char *path)
{
	char vendor_id_buf[8];
	int len;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		p_err("Can't open %s: %s", path, strerror(errno));
		return -1;
	}

	len = read(fd, vendor_id_buf, sizeof(vendor_id_buf));
	close(fd);
	if (len < 0) {
		p_err("Can't read %s: %s", path, strerror(errno));
		return -1;
	}
	if (len >= (int)sizeof(vendor_id_buf)) {
		p_err("Value in %s too long", path);
		return -1;
	}

	vendor_id_buf[len] = 0;

	return strtol(vendor_id_buf, NULL, 0);
}

static int read_sysfs_netdev_hex_int(char *devname, const char *entry_name)
{
	char full_path[64];

	snprintf(full_path, sizeof(full_path), "/sys/class/net/%s/device/%s",
		 devname, entry_name);

	return read_sysfs_hex_int(full_path);
}

const char *ifindex_to_bfd_name_ns(__u32 ifindex, __u64 ns_dev, __u64 ns_ino)
{
	char devname[IF_NAMESIZE];
	int vendor_id;
	int device_id;

	if (!ifindex_to_name_ns(ifindex, ns_dev, ns_ino, devname)) {
		p_err("Can't get net device name for ifindex %d: %s", ifindex,
		      strerror(errno));
		return NULL;
	}

	vendor_id = read_sysfs_netdev_hex_int(devname, "vendor");
	if (vendor_id < 0) {
		p_err("Can't get device vendor id for %s", devname);
		return NULL;
	}

	switch (vendor_id) {
	case 0x19ee:
		device_id = read_sysfs_netdev_hex_int(devname, "device");
		if (device_id != 0x4000 &&
		    device_id != 0x6000 &&
		    device_id != 0x6003)
			p_info("Unknown NFP device ID, assuming it is NFP-6xxx arch");
		return "NFP-6xxx";
	default:
		p_err("Can't get bfd arch name for device vendor id 0x%04x",
		      vendor_id);
		return NULL;
	}
}

void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
{
	char name[IF_NAMESIZE];

	if (!ifindex)
		return;

	printf(" dev ");
	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
		printf("%s", name);
	else
		printf("ifindex %u ns_dev %llu ns_ino %llu",
		       ifindex, ns_dev, ns_inode);
}

void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
{
	char name[IF_NAMESIZE];

	if (!ifindex)
		return;

	jsonw_name(json_wtr, "dev");
	jsonw_start_object(json_wtr);
	jsonw_uint_field(json_wtr, "ifindex", ifindex);
	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
		jsonw_string_field(json_wtr, "ifname", name);
	jsonw_end_object(json_wtr);
}