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
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
|
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/* Copyright (c) 2018 Facebook */
#include <stdlib.h>
#include <memory.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/pkt_cls.h>
#include <linux/rtnetlink.h>
#include <linux/netdev.h>
#include <sys/socket.h>
#include <errno.h>
#include <time.h>
#include "bpf.h"
#include "libbpf.h"
#include "libbpf_internal.h"
#include "nlattr.h"
#ifndef SOL_NETLINK
#define SOL_NETLINK 270
#endif
typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
void *cookie);
struct xdp_link_info {
__u32 prog_id;
__u32 drv_prog_id;
__u32 hw_prog_id;
__u32 skb_prog_id;
__u8 attach_mode;
};
struct xdp_id_md {
int ifindex;
__u32 flags;
struct xdp_link_info info;
__u64 feature_flags;
};
struct xdp_features_md {
int ifindex;
__u64 flags;
};
static int libbpf_netlink_open(__u32 *nl_pid, int proto)
{
struct sockaddr_nl sa;
socklen_t addrlen;
int one = 1, ret;
int sock;
memset(&sa, 0, sizeof(sa));
sa.nl_family = AF_NETLINK;
sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, proto);
if (sock < 0)
return -errno;
if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
&one, sizeof(one)) < 0) {
pr_warn("Netlink error reporting not supported\n");
}
if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
ret = -errno;
goto cleanup;
}
addrlen = sizeof(sa);
if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
ret = -errno;
goto cleanup;
}
if (addrlen != sizeof(sa)) {
ret = -LIBBPF_ERRNO__INTERNAL;
goto cleanup;
}
*nl_pid = sa.nl_pid;
return sock;
cleanup:
close(sock);
return ret;
}
static void libbpf_netlink_close(int sock)
{
close(sock);
}
enum {
NL_CONT,
NL_NEXT,
NL_DONE,
};
static int netlink_recvmsg(int sock, struct msghdr *mhdr, int flags)
{
int len;
do {
len = recvmsg(sock, mhdr, flags);
} while (len < 0 && (errno == EINTR || errno == EAGAIN));
if (len < 0)
return -errno;
return len;
}
static int alloc_iov(struct iovec *iov, int len)
{
void *nbuf;
nbuf = realloc(iov->iov_base, len);
if (!nbuf)
return -ENOMEM;
iov->iov_base = nbuf;
iov->iov_len = len;
return 0;
}
static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq,
__dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
void *cookie)
{
struct iovec iov = {};
struct msghdr mhdr = {
.msg_iov = &iov,
.msg_iovlen = 1,
};
bool multipart = true;
struct nlmsgerr *err;
struct nlmsghdr *nh;
int len, ret;
ret = alloc_iov(&iov, 4096);
if (ret)
goto done;
while (multipart) {
start:
multipart = false;
len = netlink_recvmsg(sock, &mhdr, MSG_PEEK | MSG_TRUNC);
if (len < 0) {
ret = len;
goto done;
}
if (len > iov.iov_len) {
ret = alloc_iov(&iov, len);
if (ret)
goto done;
}
len = netlink_recvmsg(sock, &mhdr, 0);
if (len < 0) {
ret = len;
goto done;
}
if (len == 0)
break;
for (nh = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(nh, len);
nh = NLMSG_NEXT(nh, len)) {
if (nh->nlmsg_pid != nl_pid) {
ret = -LIBBPF_ERRNO__WRNGPID;
goto done;
}
if (nh->nlmsg_seq != seq) {
ret = -LIBBPF_ERRNO__INVSEQ;
goto done;
}
if (nh->nlmsg_flags & NLM_F_MULTI)
multipart = true;
switch (nh->nlmsg_type) {
case NLMSG_ERROR:
err = (struct nlmsgerr *)NLMSG_DATA(nh);
if (!err->error)
continue;
ret = err->error;
libbpf_nla_dump_errormsg(nh);
goto done;
case NLMSG_DONE:
ret = 0;
goto done;
default:
break;
}
if (_fn) {
ret = _fn(nh, fn, cookie);
switch (ret) {
case NL_CONT:
break;
case NL_NEXT:
goto start;
case NL_DONE:
ret = 0;
goto done;
default:
goto done;
}
}
}
}
ret = 0;
done:
free(iov.iov_base);
return ret;
}
static int libbpf_netlink_send_recv(struct libbpf_nla_req *req,
int proto, __dump_nlmsg_t parse_msg,
libbpf_dump_nlmsg_t parse_attr,
void *cookie)
{
__u32 nl_pid = 0;
int sock, ret;
sock = libbpf_netlink_open(&nl_pid, proto);
if (sock < 0)
return sock;
req->nh.nlmsg_pid = 0;
req->nh.nlmsg_seq = time(NULL);
if (send(sock, req, req->nh.nlmsg_len, 0) < 0) {
ret = -errno;
goto out;
}
ret = libbpf_netlink_recv(sock, nl_pid, req->nh.nlmsg_seq,
parse_msg, parse_attr, cookie);
out:
libbpf_netlink_close(sock);
return ret;
}
static int parse_genl_family_id(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
void *cookie)
{
struct genlmsghdr *gnl = NLMSG_DATA(nh);
struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);
struct nlattr *tb[CTRL_ATTR_FAMILY_ID + 1];
__u16 *id = cookie;
libbpf_nla_parse(tb, CTRL_ATTR_FAMILY_ID, na,
NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);
if (!tb[CTRL_ATTR_FAMILY_ID])
return NL_CONT;
*id = libbpf_nla_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
return NL_DONE;
}
static int libbpf_netlink_resolve_genl_family_id(const char *name,
__u16 len, __u16 *id)
{
struct libbpf_nla_req req = {
.nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
.nh.nlmsg_type = GENL_ID_CTRL,
.nh.nlmsg_flags = NLM_F_REQUEST,
.gnl.cmd = CTRL_CMD_GETFAMILY,
.gnl.version = 2,
};
int err;
err = nlattr_add(&req, CTRL_ATTR_FAMILY_NAME, name, len);
if (err < 0)
return err;
return libbpf_netlink_send_recv(&req, NETLINK_GENERIC,
parse_genl_family_id, NULL, id);
}
static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,
__u32 flags)
{
struct nlattr *nla;
int ret;
struct libbpf_nla_req req;
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
req.nh.nlmsg_type = RTM_SETLINK;
req.ifinfo.ifi_family = AF_UNSPEC;
req.ifinfo.ifi_index = ifindex;
nla = nlattr_begin_nested(&req, IFLA_XDP);
if (!nla)
return -EMSGSIZE;
ret = nlattr_add(&req, IFLA_XDP_FD, &fd, sizeof(fd));
if (ret < 0)
return ret;
if (flags) {
ret = nlattr_add(&req, IFLA_XDP_FLAGS, &flags, sizeof(flags));
if (ret < 0)
return ret;
}
if (flags & XDP_FLAGS_REPLACE) {
ret = nlattr_add(&req, IFLA_XDP_EXPECTED_FD, &old_fd,
sizeof(old_fd));
if (ret < 0)
return ret;
}
nlattr_end_nested(&req, nla);
return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);
}
int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, const struct bpf_xdp_attach_opts *opts)
{
int old_prog_fd, err;
if (!OPTS_VALID(opts, bpf_xdp_attach_opts))
return libbpf_err(-EINVAL);
old_prog_fd = OPTS_GET(opts, old_prog_fd, 0);
if (old_prog_fd)
flags |= XDP_FLAGS_REPLACE;
else
old_prog_fd = -1;
err = __bpf_set_link_xdp_fd_replace(ifindex, prog_fd, old_prog_fd, flags);
return libbpf_err(err);
}
int bpf_xdp_detach(int ifindex, __u32 flags, const struct bpf_xdp_attach_opts *opts)
{
return bpf_xdp_attach(ifindex, -1, flags, opts);
}
static int __dump_link_nlmsg(struct nlmsghdr *nlh,
libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
{
struct nlattr *tb[IFLA_MAX + 1], *attr;
struct ifinfomsg *ifi = NLMSG_DATA(nlh);
int len;
len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
return -LIBBPF_ERRNO__NLPARSE;
return dump_link_nlmsg(cookie, ifi, tb);
}
static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb)
{
struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
struct xdp_id_md *xdp_id = cookie;
struct ifinfomsg *ifinfo = msg;
int ret;
if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
return 0;
if (!tb[IFLA_XDP])
return 0;
ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
if (ret)
return ret;
if (!xdp_tb[IFLA_XDP_ATTACHED])
return 0;
xdp_id->info.attach_mode = libbpf_nla_getattr_u8(
xdp_tb[IFLA_XDP_ATTACHED]);
if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE)
return 0;
if (xdp_tb[IFLA_XDP_PROG_ID])
xdp_id->info.prog_id = libbpf_nla_getattr_u32(
xdp_tb[IFLA_XDP_PROG_ID]);
if (xdp_tb[IFLA_XDP_SKB_PROG_ID])
xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32(
xdp_tb[IFLA_XDP_SKB_PROG_ID]);
if (xdp_tb[IFLA_XDP_DRV_PROG_ID])
xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32(
xdp_tb[IFLA_XDP_DRV_PROG_ID]);
if (xdp_tb[IFLA_XDP_HW_PROG_ID])
xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32(
xdp_tb[IFLA_XDP_HW_PROG_ID]);
return 0;
}
static int parse_xdp_features(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
void *cookie)
{
struct genlmsghdr *gnl = NLMSG_DATA(nh);
struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);
struct nlattr *tb[NETDEV_CMD_MAX + 1];
struct xdp_features_md *md = cookie;
__u32 ifindex;
libbpf_nla_parse(tb, NETDEV_CMD_MAX, na,
NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);
if (!tb[NETDEV_A_DEV_IFINDEX] || !tb[NETDEV_A_DEV_XDP_FEATURES])
return NL_CONT;
ifindex = libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_IFINDEX]);
if (ifindex != md->ifindex)
return NL_CONT;
md->flags = libbpf_nla_getattr_u64(tb[NETDEV_A_DEV_XDP_FEATURES]);
return NL_DONE;
}
int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
{
struct libbpf_nla_req req = {
.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
.nh.nlmsg_type = RTM_GETLINK,
.nh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
.ifinfo.ifi_family = AF_PACKET,
};
struct xdp_id_md xdp_id = {};
struct xdp_features_md md = {
.ifindex = ifindex,
};
__u16 id;
int err;
if (!OPTS_VALID(opts, bpf_xdp_query_opts))
return libbpf_err(-EINVAL);
if (xdp_flags & ~XDP_FLAGS_MASK)
return libbpf_err(-EINVAL);
/* Check whether the single {HW,DRV,SKB} mode is set */
xdp_flags &= XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE;
if (xdp_flags & (xdp_flags - 1))
return libbpf_err(-EINVAL);
xdp_id.ifindex = ifindex;
xdp_id.flags = xdp_flags;
err = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, __dump_link_nlmsg,
get_xdp_info, &xdp_id);
if (err)
return libbpf_err(err);
OPTS_SET(opts, prog_id, xdp_id.info.prog_id);
OPTS_SET(opts, drv_prog_id, xdp_id.info.drv_prog_id);
OPTS_SET(opts, hw_prog_id, xdp_id.info.hw_prog_id);
OPTS_SET(opts, skb_prog_id, xdp_id.info.skb_prog_id);
OPTS_SET(opts, attach_mode, xdp_id.info.attach_mode);
if (!OPTS_HAS(opts, feature_flags))
return 0;
err = libbpf_netlink_resolve_genl_family_id("netdev", sizeof("netdev"), &id);
if (err < 0)
return libbpf_err(err);
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
req.nh.nlmsg_flags = NLM_F_REQUEST;
req.nh.nlmsg_type = id;
req.gnl.cmd = NETDEV_CMD_DEV_GET;
req.gnl.version = 2;
err = nlattr_add(&req, NETDEV_A_DEV_IFINDEX, &ifindex, sizeof(ifindex));
if (err < 0)
return libbpf_err(err);
err = libbpf_netlink_send_recv(&req, NETLINK_GENERIC,
parse_xdp_features, NULL, &md);
if (err)
return libbpf_err(err);
opts->feature_flags = md.flags;
return 0;
}
int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id)
{
LIBBPF_OPTS(bpf_xdp_query_opts, opts);
int ret;
ret = bpf_xdp_query(ifindex, flags, &opts);
if (ret)
return libbpf_err(ret);
flags &= XDP_FLAGS_MODES;
if (opts.attach_mode != XDP_ATTACHED_MULTI && !flags)
*prog_id = opts.prog_id;
else if (flags & XDP_FLAGS_DRV_MODE)
*prog_id = opts.drv_prog_id;
else if (flags & XDP_FLAGS_HW_MODE)
*prog_id = opts.hw_prog_id;
else if (flags & XDP_FLAGS_SKB_MODE)
*prog_id = opts.skb_prog_id;
else
*prog_id = 0;
return 0;
}
typedef int (*qdisc_config_t)(struct libbpf_nla_req *req);
static int clsact_config(struct libbpf_nla_req *req)
{
req->tc.tcm_parent = TC_H_CLSACT;
req->tc.tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0);
return nlattr_add(req, TCA_KIND, "clsact", sizeof("clsact"));
}
static int attach_point_to_config(struct bpf_tc_hook *hook,
qdisc_config_t *config)
{
switch (OPTS_GET(hook, attach_point, 0)) {
case BPF_TC_INGRESS:
case BPF_TC_EGRESS:
case BPF_TC_INGRESS | BPF_TC_EGRESS:
if (OPTS_GET(hook, parent, 0))
return -EINVAL;
*config = &clsact_config;
return 0;
case BPF_TC_CUSTOM:
return -EOPNOTSUPP;
default:
return -EINVAL;
}
}
static int tc_get_tcm_parent(enum bpf_tc_attach_point attach_point,
__u32 *parent)
{
switch (attach_point) {
case BPF_TC_INGRESS:
case BPF_TC_EGRESS:
if (*parent)
return -EINVAL;
*parent = TC_H_MAKE(TC_H_CLSACT,
attach_point == BPF_TC_INGRESS ?
TC_H_MIN_INGRESS : TC_H_MIN_EGRESS);
break;
case BPF_TC_CUSTOM:
if (!*parent)
return -EINVAL;
break;
default:
return -EINVAL;
}
return 0;
}
static int tc_qdisc_modify(struct bpf_tc_hook *hook, int cmd, int flags)
{
qdisc_config_t config;
int ret;
struct libbpf_nla_req req;
ret = attach_point_to_config(hook, &config);
if (ret < 0)
return ret;
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
req.nh.nlmsg_type = cmd;
req.tc.tcm_family = AF_UNSPEC;
req.tc.tcm_ifindex = OPTS_GET(hook, ifindex, 0);
ret = config(&req);
if (ret < 0)
return ret;
return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);
}
static int tc_qdisc_create_excl(struct bpf_tc_hook *hook)
{
return tc_qdisc_modify(hook, RTM_NEWQDISC, NLM_F_CREATE | NLM_F_EXCL);
}
static int tc_qdisc_delete(struct bpf_tc_hook *hook)
{
return tc_qdisc_modify(hook, RTM_DELQDISC, 0);
}
int bpf_tc_hook_create(struct bpf_tc_hook *hook)
{
int ret;
if (!hook || !OPTS_VALID(hook, bpf_tc_hook) ||
OPTS_GET(hook, ifindex, 0) <= 0)
return libbpf_err(-EINVAL);
ret = tc_qdisc_create_excl(hook);
return libbpf_err(ret);
}
static int __bpf_tc_detach(const struct bpf_tc_hook *hook,
const struct bpf_tc_opts *opts,
const bool flush);
int bpf_tc_hook_destroy(struct bpf_tc_hook *hook)
{
if (!hook || !OPTS_VALID(hook, bpf_tc_hook) ||
OPTS_GET(hook, ifindex, 0) <= 0)
return libbpf_err(-EINVAL);
switch (OPTS_GET(hook, attach_point, 0)) {
case BPF_TC_INGRESS:
case BPF_TC_EGRESS:
return libbpf_err(__bpf_tc_detach(hook, NULL, true));
case BPF_TC_INGRESS | BPF_TC_EGRESS:
return libbpf_err(tc_qdisc_delete(hook));
case BPF_TC_CUSTOM:
return libbpf_err(-EOPNOTSUPP);
default:
return libbpf_err(-EINVAL);
}
}
struct bpf_cb_ctx {
struct bpf_tc_opts *opts;
bool processed;
};
static int __get_tc_info(void *cookie, struct tcmsg *tc, struct nlattr **tb,
bool unicast)
{
struct nlattr *tbb[TCA_BPF_MAX + 1];
struct bpf_cb_ctx *info = cookie;
if (!info || !info->opts)
return -EINVAL;
if (unicast && info->processed)
return -EINVAL;
if (!tb[TCA_OPTIONS])
return NL_CONT;
libbpf_nla_parse_nested(tbb, TCA_BPF_MAX, tb[TCA_OPTIONS], NULL);
if (!tbb[TCA_BPF_ID])
return -EINVAL;
OPTS_SET(info->opts, prog_id, libbpf_nla_getattr_u32(tbb[TCA_BPF_ID]));
OPTS_SET(info->opts, handle, tc->tcm_handle);
OPTS_SET(info->opts, priority, TC_H_MAJ(tc->tcm_info) >> 16);
info->processed = true;
return unicast ? NL_NEXT : NL_DONE;
}
static int get_tc_info(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
void *cookie)
{
struct tcmsg *tc = NLMSG_DATA(nh);
struct nlattr *tb[TCA_MAX + 1];
libbpf_nla_parse(tb, TCA_MAX,
(struct nlattr *)((void *)tc + NLMSG_ALIGN(sizeof(*tc))),
NLMSG_PAYLOAD(nh, sizeof(*tc)), NULL);
if (!tb[TCA_KIND])
return NL_CONT;
return __get_tc_info(cookie, tc, tb, nh->nlmsg_flags & NLM_F_ECHO);
}
static int tc_add_fd_and_name(struct libbpf_nla_req *req, int fd)
{
struct bpf_prog_info info;
__u32 info_len = sizeof(info);
char name[256];
int len, ret;
memset(&info, 0, info_len);
ret = bpf_obj_get_info_by_fd(fd, &info, &info_len);
if (ret < 0)
return ret;
ret = nlattr_add(req, TCA_BPF_FD, &fd, sizeof(fd));
if (ret < 0)
return ret;
len = snprintf(name, sizeof(name), "%s:[%u]", info.name, info.id);
if (len < 0)
return -errno;
if (len >= sizeof(name))
return -ENAMETOOLONG;
return nlattr_add(req, TCA_BPF_NAME, name, len + 1);
}
int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts)
{
__u32 protocol, bpf_flags, handle, priority, parent, prog_id, flags;
int ret, ifindex, attach_point, prog_fd;
struct bpf_cb_ctx info = {};
struct libbpf_nla_req req;
struct nlattr *nla;
if (!hook || !opts ||
!OPTS_VALID(hook, bpf_tc_hook) ||
!OPTS_VALID(opts, bpf_tc_opts))
return libbpf_err(-EINVAL);
ifindex = OPTS_GET(hook, ifindex, 0);
parent = OPTS_GET(hook, parent, 0);
attach_point = OPTS_GET(hook, attach_point, 0);
handle = OPTS_GET(opts, handle, 0);
priority = OPTS_GET(opts, priority, 0);
prog_fd = OPTS_GET(opts, prog_fd, 0);
prog_id = OPTS_GET(opts, prog_id, 0);
flags = OPTS_GET(opts, flags, 0);
if (ifindex <= 0 || !prog_fd || prog_id)
return libbpf_err(-EINVAL);
if (priority > UINT16_MAX)
return libbpf_err(-EINVAL);
if (flags & ~BPF_TC_F_REPLACE)
return libbpf_err(-EINVAL);
flags = (flags & BPF_TC_F_REPLACE) ? NLM_F_REPLACE : NLM_F_EXCL;
protocol = ETH_P_ALL;
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE |
NLM_F_ECHO | flags;
req.nh.nlmsg_type = RTM_NEWTFILTER;
req.tc.tcm_family = AF_UNSPEC;
req.tc.tcm_ifindex = ifindex;
req.tc.tcm_handle = handle;
req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));
ret = tc_get_tcm_parent(attach_point, &parent);
if (ret < 0)
return libbpf_err(ret);
req.tc.tcm_parent = parent;
ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));
if (ret < 0)
return libbpf_err(ret);
nla = nlattr_begin_nested(&req, TCA_OPTIONS);
if (!nla)
return libbpf_err(-EMSGSIZE);
ret = tc_add_fd_and_name(&req, prog_fd);
if (ret < 0)
return libbpf_err(ret);
bpf_flags = TCA_BPF_FLAG_ACT_DIRECT;
ret = nlattr_add(&req, TCA_BPF_FLAGS, &bpf_flags, sizeof(bpf_flags));
if (ret < 0)
return libbpf_err(ret);
nlattr_end_nested(&req, nla);
info.opts = opts;
ret = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, get_tc_info, NULL,
&info);
if (ret < 0)
return libbpf_err(ret);
if (!info.processed)
return libbpf_err(-ENOENT);
return ret;
}
static int __bpf_tc_detach(const struct bpf_tc_hook *hook,
const struct bpf_tc_opts *opts,
const bool flush)
{
__u32 protocol = 0, handle, priority, parent, prog_id, flags;
int ret, ifindex, attach_point, prog_fd;
struct libbpf_nla_req req;
if (!hook ||
!OPTS_VALID(hook, bpf_tc_hook) ||
!OPTS_VALID(opts, bpf_tc_opts))
return -EINVAL;
ifindex = OPTS_GET(hook, ifindex, 0);
parent = OPTS_GET(hook, parent, 0);
attach_point = OPTS_GET(hook, attach_point, 0);
handle = OPTS_GET(opts, handle, 0);
priority = OPTS_GET(opts, priority, 0);
prog_fd = OPTS_GET(opts, prog_fd, 0);
prog_id = OPTS_GET(opts, prog_id, 0);
flags = OPTS_GET(opts, flags, 0);
if (ifindex <= 0 || flags || prog_fd || prog_id)
return -EINVAL;
if (priority > UINT16_MAX)
return -EINVAL;
if (!flush) {
if (!handle || !priority)
return -EINVAL;
protocol = ETH_P_ALL;
} else {
if (handle || priority)
return -EINVAL;
}
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
req.nh.nlmsg_type = RTM_DELTFILTER;
req.tc.tcm_family = AF_UNSPEC;
req.tc.tcm_ifindex = ifindex;
if (!flush) {
req.tc.tcm_handle = handle;
req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));
}
ret = tc_get_tcm_parent(attach_point, &parent);
if (ret < 0)
return ret;
req.tc.tcm_parent = parent;
if (!flush) {
ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));
if (ret < 0)
return ret;
}
return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);
}
int bpf_tc_detach(const struct bpf_tc_hook *hook,
const struct bpf_tc_opts *opts)
{
int ret;
if (!opts)
return libbpf_err(-EINVAL);
ret = __bpf_tc_detach(hook, opts, false);
return libbpf_err(ret);
}
int bpf_tc_query(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts)
{
__u32 protocol, handle, priority, parent, prog_id, flags;
int ret, ifindex, attach_point, prog_fd;
struct bpf_cb_ctx info = {};
struct libbpf_nla_req req;
if (!hook || !opts ||
!OPTS_VALID(hook, bpf_tc_hook) ||
!OPTS_VALID(opts, bpf_tc_opts))
return libbpf_err(-EINVAL);
ifindex = OPTS_GET(hook, ifindex, 0);
parent = OPTS_GET(hook, parent, 0);
attach_point = OPTS_GET(hook, attach_point, 0);
handle = OPTS_GET(opts, handle, 0);
priority = OPTS_GET(opts, priority, 0);
prog_fd = OPTS_GET(opts, prog_fd, 0);
prog_id = OPTS_GET(opts, prog_id, 0);
flags = OPTS_GET(opts, flags, 0);
if (ifindex <= 0 || flags || prog_fd || prog_id ||
!handle || !priority)
return libbpf_err(-EINVAL);
if (priority > UINT16_MAX)
return libbpf_err(-EINVAL);
protocol = ETH_P_ALL;
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
req.nh.nlmsg_flags = NLM_F_REQUEST;
req.nh.nlmsg_type = RTM_GETTFILTER;
req.tc.tcm_family = AF_UNSPEC;
req.tc.tcm_ifindex = ifindex;
req.tc.tcm_handle = handle;
req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));
ret = tc_get_tcm_parent(attach_point, &parent);
if (ret < 0)
return libbpf_err(ret);
req.tc.tcm_parent = parent;
ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));
if (ret < 0)
return libbpf_err(ret);
info.opts = opts;
ret = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, get_tc_info, NULL,
&info);
if (ret < 0)
return libbpf_err(ret);
if (!info.processed)
return libbpf_err(-ENOENT);
return ret;
}
|