Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2/* Copyright (c) 2018 Facebook */
3
4#include <stdlib.h>
5#include <memory.h>
6#include <unistd.h>
7#include <arpa/inet.h>
8#include <linux/bpf.h>
9#include <linux/if_ether.h>
10#include <linux/pkt_cls.h>
11#include <linux/rtnetlink.h>
12#include <linux/netdev.h>
13#include <sys/socket.h>
14#include <errno.h>
15#include <time.h>
16
17#include "bpf.h"
18#include "libbpf.h"
19#include "libbpf_internal.h"
20#include "nlattr.h"
21
22#ifndef SOL_NETLINK
23#define SOL_NETLINK 270
24#endif
25
26typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
27
28typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
29 void *cookie);
30
31struct xdp_link_info {
32 __u32 prog_id;
33 __u32 drv_prog_id;
34 __u32 hw_prog_id;
35 __u32 skb_prog_id;
36 __u8 attach_mode;
37};
38
39struct xdp_id_md {
40 int ifindex;
41 __u32 flags;
42 struct xdp_link_info info;
43 __u64 feature_flags;
44};
45
46struct xdp_features_md {
47 int ifindex;
48 __u32 xdp_zc_max_segs;
49 __u64 flags;
50};
51
52static int libbpf_netlink_open(__u32 *nl_pid, int proto)
53{
54 struct sockaddr_nl sa;
55 socklen_t addrlen;
56 int one = 1, ret;
57 int sock;
58
59 memset(&sa, 0, sizeof(sa));
60 sa.nl_family = AF_NETLINK;
61
62 sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, proto);
63 if (sock < 0)
64 return -errno;
65
66 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
67 &one, sizeof(one)) < 0) {
68 pr_warn("Netlink error reporting not supported\n");
69 }
70
71 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
72 ret = -errno;
73 goto cleanup;
74 }
75
76 addrlen = sizeof(sa);
77 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
78 ret = -errno;
79 goto cleanup;
80 }
81
82 if (addrlen != sizeof(sa)) {
83 ret = -LIBBPF_ERRNO__INTERNAL;
84 goto cleanup;
85 }
86
87 *nl_pid = sa.nl_pid;
88 return sock;
89
90cleanup:
91 close(sock);
92 return ret;
93}
94
95static void libbpf_netlink_close(int sock)
96{
97 close(sock);
98}
99
100enum {
101 NL_CONT,
102 NL_NEXT,
103 NL_DONE,
104};
105
106static int netlink_recvmsg(int sock, struct msghdr *mhdr, int flags)
107{
108 int len;
109
110 do {
111 len = recvmsg(sock, mhdr, flags);
112 } while (len < 0 && (errno == EINTR || errno == EAGAIN));
113
114 if (len < 0)
115 return -errno;
116 return len;
117}
118
119static int alloc_iov(struct iovec *iov, int len)
120{
121 void *nbuf;
122
123 nbuf = realloc(iov->iov_base, len);
124 if (!nbuf)
125 return -ENOMEM;
126
127 iov->iov_base = nbuf;
128 iov->iov_len = len;
129 return 0;
130}
131
132static int libbpf_netlink_recv(int sock, __u32 nl_pid, int seq,
133 __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
134 void *cookie)
135{
136 struct iovec iov = {};
137 struct msghdr mhdr = {
138 .msg_iov = &iov,
139 .msg_iovlen = 1,
140 };
141 bool multipart = true;
142 struct nlmsgerr *err;
143 struct nlmsghdr *nh;
144 int len, ret;
145
146 ret = alloc_iov(&iov, 4096);
147 if (ret)
148 goto done;
149
150 while (multipart) {
151start:
152 multipart = false;
153 len = netlink_recvmsg(sock, &mhdr, MSG_PEEK | MSG_TRUNC);
154 if (len < 0) {
155 ret = len;
156 goto done;
157 }
158
159 if (len > iov.iov_len) {
160 ret = alloc_iov(&iov, len);
161 if (ret)
162 goto done;
163 }
164
165 len = netlink_recvmsg(sock, &mhdr, 0);
166 if (len < 0) {
167 ret = len;
168 goto done;
169 }
170
171 if (len == 0)
172 break;
173
174 for (nh = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(nh, len);
175 nh = NLMSG_NEXT(nh, len)) {
176 if (nh->nlmsg_pid != nl_pid) {
177 ret = -LIBBPF_ERRNO__WRNGPID;
178 goto done;
179 }
180 if (nh->nlmsg_seq != seq) {
181 ret = -LIBBPF_ERRNO__INVSEQ;
182 goto done;
183 }
184 if (nh->nlmsg_flags & NLM_F_MULTI)
185 multipart = true;
186 switch (nh->nlmsg_type) {
187 case NLMSG_ERROR:
188 err = (struct nlmsgerr *)NLMSG_DATA(nh);
189 if (!err->error)
190 continue;
191 ret = err->error;
192 libbpf_nla_dump_errormsg(nh);
193 goto done;
194 case NLMSG_DONE:
195 ret = 0;
196 goto done;
197 default:
198 break;
199 }
200 if (_fn) {
201 ret = _fn(nh, fn, cookie);
202 switch (ret) {
203 case NL_CONT:
204 break;
205 case NL_NEXT:
206 goto start;
207 case NL_DONE:
208 ret = 0;
209 goto done;
210 default:
211 goto done;
212 }
213 }
214 }
215 }
216 ret = 0;
217done:
218 free(iov.iov_base);
219 return ret;
220}
221
222static int libbpf_netlink_send_recv(struct libbpf_nla_req *req,
223 int proto, __dump_nlmsg_t parse_msg,
224 libbpf_dump_nlmsg_t parse_attr,
225 void *cookie)
226{
227 __u32 nl_pid = 0;
228 int sock, ret;
229
230 sock = libbpf_netlink_open(&nl_pid, proto);
231 if (sock < 0)
232 return sock;
233
234 req->nh.nlmsg_pid = 0;
235 req->nh.nlmsg_seq = time(NULL);
236
237 if (send(sock, req, req->nh.nlmsg_len, 0) < 0) {
238 ret = -errno;
239 goto out;
240 }
241
242 ret = libbpf_netlink_recv(sock, nl_pid, req->nh.nlmsg_seq,
243 parse_msg, parse_attr, cookie);
244out:
245 libbpf_netlink_close(sock);
246 return ret;
247}
248
249static int parse_genl_family_id(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
250 void *cookie)
251{
252 struct genlmsghdr *gnl = NLMSG_DATA(nh);
253 struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);
254 struct nlattr *tb[CTRL_ATTR_FAMILY_ID + 1];
255 __u16 *id = cookie;
256
257 libbpf_nla_parse(tb, CTRL_ATTR_FAMILY_ID, na,
258 NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);
259 if (!tb[CTRL_ATTR_FAMILY_ID])
260 return NL_CONT;
261
262 *id = libbpf_nla_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
263 return NL_DONE;
264}
265
266static int libbpf_netlink_resolve_genl_family_id(const char *name,
267 __u16 len, __u16 *id)
268{
269 struct libbpf_nla_req req = {
270 .nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
271 .nh.nlmsg_type = GENL_ID_CTRL,
272 .nh.nlmsg_flags = NLM_F_REQUEST,
273 .gnl.cmd = CTRL_CMD_GETFAMILY,
274 .gnl.version = 2,
275 };
276 int err;
277
278 err = nlattr_add(&req, CTRL_ATTR_FAMILY_NAME, name, len);
279 if (err < 0)
280 return err;
281
282 return libbpf_netlink_send_recv(&req, NETLINK_GENERIC,
283 parse_genl_family_id, NULL, id);
284}
285
286static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,
287 __u32 flags)
288{
289 struct nlattr *nla;
290 int ret;
291 struct libbpf_nla_req req;
292
293 memset(&req, 0, sizeof(req));
294 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
295 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
296 req.nh.nlmsg_type = RTM_SETLINK;
297 req.ifinfo.ifi_family = AF_UNSPEC;
298 req.ifinfo.ifi_index = ifindex;
299
300 nla = nlattr_begin_nested(&req, IFLA_XDP);
301 if (!nla)
302 return -EMSGSIZE;
303 ret = nlattr_add(&req, IFLA_XDP_FD, &fd, sizeof(fd));
304 if (ret < 0)
305 return ret;
306 if (flags) {
307 ret = nlattr_add(&req, IFLA_XDP_FLAGS, &flags, sizeof(flags));
308 if (ret < 0)
309 return ret;
310 }
311 if (flags & XDP_FLAGS_REPLACE) {
312 ret = nlattr_add(&req, IFLA_XDP_EXPECTED_FD, &old_fd,
313 sizeof(old_fd));
314 if (ret < 0)
315 return ret;
316 }
317 nlattr_end_nested(&req, nla);
318
319 return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);
320}
321
322int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, const struct bpf_xdp_attach_opts *opts)
323{
324 int old_prog_fd, err;
325
326 if (!OPTS_VALID(opts, bpf_xdp_attach_opts))
327 return libbpf_err(-EINVAL);
328
329 old_prog_fd = OPTS_GET(opts, old_prog_fd, 0);
330 if (old_prog_fd)
331 flags |= XDP_FLAGS_REPLACE;
332 else
333 old_prog_fd = -1;
334
335 err = __bpf_set_link_xdp_fd_replace(ifindex, prog_fd, old_prog_fd, flags);
336 return libbpf_err(err);
337}
338
339int bpf_xdp_detach(int ifindex, __u32 flags, const struct bpf_xdp_attach_opts *opts)
340{
341 return bpf_xdp_attach(ifindex, -1, flags, opts);
342}
343
344static int __dump_link_nlmsg(struct nlmsghdr *nlh,
345 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
346{
347 struct nlattr *tb[IFLA_MAX + 1], *attr;
348 struct ifinfomsg *ifi = NLMSG_DATA(nlh);
349 int len;
350
351 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
352 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
353
354 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
355 return -LIBBPF_ERRNO__NLPARSE;
356
357 return dump_link_nlmsg(cookie, ifi, tb);
358}
359
360static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb)
361{
362 struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
363 struct xdp_id_md *xdp_id = cookie;
364 struct ifinfomsg *ifinfo = msg;
365 int ret;
366
367 if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
368 return 0;
369
370 if (!tb[IFLA_XDP])
371 return 0;
372
373 ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
374 if (ret)
375 return ret;
376
377 if (!xdp_tb[IFLA_XDP_ATTACHED])
378 return 0;
379
380 xdp_id->info.attach_mode = libbpf_nla_getattr_u8(
381 xdp_tb[IFLA_XDP_ATTACHED]);
382
383 if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE)
384 return 0;
385
386 if (xdp_tb[IFLA_XDP_PROG_ID])
387 xdp_id->info.prog_id = libbpf_nla_getattr_u32(
388 xdp_tb[IFLA_XDP_PROG_ID]);
389
390 if (xdp_tb[IFLA_XDP_SKB_PROG_ID])
391 xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32(
392 xdp_tb[IFLA_XDP_SKB_PROG_ID]);
393
394 if (xdp_tb[IFLA_XDP_DRV_PROG_ID])
395 xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32(
396 xdp_tb[IFLA_XDP_DRV_PROG_ID]);
397
398 if (xdp_tb[IFLA_XDP_HW_PROG_ID])
399 xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32(
400 xdp_tb[IFLA_XDP_HW_PROG_ID]);
401
402 return 0;
403}
404
405static int parse_xdp_features(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
406 void *cookie)
407{
408 struct genlmsghdr *gnl = NLMSG_DATA(nh);
409 struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);
410 struct nlattr *tb[NETDEV_CMD_MAX + 1];
411 struct xdp_features_md *md = cookie;
412 __u32 ifindex;
413
414 libbpf_nla_parse(tb, NETDEV_CMD_MAX, na,
415 NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);
416
417 if (!tb[NETDEV_A_DEV_IFINDEX] || !tb[NETDEV_A_DEV_XDP_FEATURES])
418 return NL_CONT;
419
420 ifindex = libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_IFINDEX]);
421 if (ifindex != md->ifindex)
422 return NL_CONT;
423
424 md->flags = libbpf_nla_getattr_u64(tb[NETDEV_A_DEV_XDP_FEATURES]);
425 if (tb[NETDEV_A_DEV_XDP_ZC_MAX_SEGS])
426 md->xdp_zc_max_segs =
427 libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_XDP_ZC_MAX_SEGS]);
428 return NL_DONE;
429}
430
431int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
432{
433 struct libbpf_nla_req req = {
434 .nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
435 .nh.nlmsg_type = RTM_GETLINK,
436 .nh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
437 .ifinfo.ifi_family = AF_PACKET,
438 };
439 struct xdp_id_md xdp_id = {};
440 struct xdp_features_md md = {
441 .ifindex = ifindex,
442 };
443 __u16 id;
444 int err;
445
446 if (!OPTS_VALID(opts, bpf_xdp_query_opts))
447 return libbpf_err(-EINVAL);
448
449 if (xdp_flags & ~XDP_FLAGS_MASK)
450 return libbpf_err(-EINVAL);
451
452 /* Check whether the single {HW,DRV,SKB} mode is set */
453 xdp_flags &= XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE;
454 if (xdp_flags & (xdp_flags - 1))
455 return libbpf_err(-EINVAL);
456
457 xdp_id.ifindex = ifindex;
458 xdp_id.flags = xdp_flags;
459
460 err = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, __dump_link_nlmsg,
461 get_xdp_info, &xdp_id);
462 if (err)
463 return libbpf_err(err);
464
465 OPTS_SET(opts, prog_id, xdp_id.info.prog_id);
466 OPTS_SET(opts, drv_prog_id, xdp_id.info.drv_prog_id);
467 OPTS_SET(opts, hw_prog_id, xdp_id.info.hw_prog_id);
468 OPTS_SET(opts, skb_prog_id, xdp_id.info.skb_prog_id);
469 OPTS_SET(opts, attach_mode, xdp_id.info.attach_mode);
470
471 if (!OPTS_HAS(opts, feature_flags))
472 return 0;
473
474 err = libbpf_netlink_resolve_genl_family_id("netdev", sizeof("netdev"), &id);
475 if (err < 0) {
476 if (err == -ENOENT) {
477 opts->feature_flags = 0;
478 goto skip_feature_flags;
479 }
480 return libbpf_err(err);
481 }
482
483 memset(&req, 0, sizeof(req));
484 req.nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
485 req.nh.nlmsg_flags = NLM_F_REQUEST;
486 req.nh.nlmsg_type = id;
487 req.gnl.cmd = NETDEV_CMD_DEV_GET;
488 req.gnl.version = 2;
489
490 err = nlattr_add(&req, NETDEV_A_DEV_IFINDEX, &ifindex, sizeof(ifindex));
491 if (err < 0)
492 return libbpf_err(err);
493
494 err = libbpf_netlink_send_recv(&req, NETLINK_GENERIC,
495 parse_xdp_features, NULL, &md);
496 if (err)
497 return libbpf_err(err);
498
499 OPTS_SET(opts, feature_flags, md.flags);
500 OPTS_SET(opts, xdp_zc_max_segs, md.xdp_zc_max_segs);
501
502skip_feature_flags:
503 return 0;
504}
505
506int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id)
507{
508 LIBBPF_OPTS(bpf_xdp_query_opts, opts);
509 int ret;
510
511 ret = bpf_xdp_query(ifindex, flags, &opts);
512 if (ret)
513 return libbpf_err(ret);
514
515 flags &= XDP_FLAGS_MODES;
516
517 if (opts.attach_mode != XDP_ATTACHED_MULTI && !flags)
518 *prog_id = opts.prog_id;
519 else if (flags & XDP_FLAGS_DRV_MODE)
520 *prog_id = opts.drv_prog_id;
521 else if (flags & XDP_FLAGS_HW_MODE)
522 *prog_id = opts.hw_prog_id;
523 else if (flags & XDP_FLAGS_SKB_MODE)
524 *prog_id = opts.skb_prog_id;
525 else
526 *prog_id = 0;
527
528 return 0;
529}
530
531
532typedef int (*qdisc_config_t)(struct libbpf_nla_req *req, const struct bpf_tc_hook *hook);
533
534static int clsact_config(struct libbpf_nla_req *req, const struct bpf_tc_hook *hook)
535{
536 req->tc.tcm_parent = TC_H_CLSACT;
537 req->tc.tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0);
538
539 return nlattr_add(req, TCA_KIND, "clsact", sizeof("clsact"));
540}
541
542static int qdisc_config(struct libbpf_nla_req *req, const struct bpf_tc_hook *hook)
543{
544 const char *qdisc = OPTS_GET(hook, qdisc, NULL);
545
546 req->tc.tcm_parent = OPTS_GET(hook, parent, TC_H_ROOT);
547 req->tc.tcm_handle = OPTS_GET(hook, handle, 0);
548
549 return nlattr_add(req, TCA_KIND, qdisc, strlen(qdisc) + 1);
550}
551
552static int attach_point_to_config(struct bpf_tc_hook *hook,
553 qdisc_config_t *config)
554{
555 switch (OPTS_GET(hook, attach_point, 0)) {
556 case BPF_TC_INGRESS:
557 case BPF_TC_EGRESS:
558 case BPF_TC_INGRESS | BPF_TC_EGRESS:
559 if (OPTS_GET(hook, parent, 0))
560 return -EINVAL;
561 *config = &clsact_config;
562 return 0;
563 case BPF_TC_CUSTOM:
564 return -EOPNOTSUPP;
565 case BPF_TC_QDISC:
566 *config = &qdisc_config;
567 return 0;
568 default:
569 return -EINVAL;
570 }
571}
572
573static int tc_get_tcm_parent(enum bpf_tc_attach_point attach_point,
574 __u32 *parent)
575{
576 switch (attach_point) {
577 case BPF_TC_INGRESS:
578 case BPF_TC_EGRESS:
579 if (*parent)
580 return -EINVAL;
581 *parent = TC_H_MAKE(TC_H_CLSACT,
582 attach_point == BPF_TC_INGRESS ?
583 TC_H_MIN_INGRESS : TC_H_MIN_EGRESS);
584 break;
585 case BPF_TC_CUSTOM:
586 if (!*parent)
587 return -EINVAL;
588 break;
589 default:
590 return -EINVAL;
591 }
592 return 0;
593}
594
595static int tc_qdisc_modify(struct bpf_tc_hook *hook, int cmd, int flags)
596{
597 qdisc_config_t config;
598 int ret;
599 struct libbpf_nla_req req;
600
601 ret = attach_point_to_config(hook, &config);
602 if (ret < 0)
603 return ret;
604
605 memset(&req, 0, sizeof(req));
606 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
607 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
608 req.nh.nlmsg_type = cmd;
609 req.tc.tcm_family = AF_UNSPEC;
610 req.tc.tcm_ifindex = OPTS_GET(hook, ifindex, 0);
611
612 ret = config(&req, hook);
613 if (ret < 0)
614 return ret;
615
616 return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);
617}
618
619static int tc_qdisc_create_excl(struct bpf_tc_hook *hook)
620{
621 return tc_qdisc_modify(hook, RTM_NEWQDISC, NLM_F_CREATE | NLM_F_EXCL);
622}
623
624static int tc_qdisc_delete(struct bpf_tc_hook *hook)
625{
626 return tc_qdisc_modify(hook, RTM_DELQDISC, 0);
627}
628
629int bpf_tc_hook_create(struct bpf_tc_hook *hook)
630{
631 int ret;
632
633 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) ||
634 OPTS_GET(hook, ifindex, 0) <= 0)
635 return libbpf_err(-EINVAL);
636
637 ret = tc_qdisc_create_excl(hook);
638 return libbpf_err(ret);
639}
640
641static int __bpf_tc_detach(const struct bpf_tc_hook *hook,
642 const struct bpf_tc_opts *opts,
643 const bool flush);
644
645int bpf_tc_hook_destroy(struct bpf_tc_hook *hook)
646{
647 if (!hook || !OPTS_VALID(hook, bpf_tc_hook) ||
648 OPTS_GET(hook, ifindex, 0) <= 0)
649 return libbpf_err(-EINVAL);
650
651 switch (OPTS_GET(hook, attach_point, 0)) {
652 case BPF_TC_INGRESS:
653 case BPF_TC_EGRESS:
654 return libbpf_err(__bpf_tc_detach(hook, NULL, true));
655 case BPF_TC_QDISC:
656 case BPF_TC_INGRESS | BPF_TC_EGRESS:
657 return libbpf_err(tc_qdisc_delete(hook));
658 case BPF_TC_CUSTOM:
659 return libbpf_err(-EOPNOTSUPP);
660 default:
661 return libbpf_err(-EINVAL);
662 }
663}
664
665struct bpf_cb_ctx {
666 struct bpf_tc_opts *opts;
667 bool processed;
668};
669
670static int __get_tc_info(void *cookie, struct tcmsg *tc, struct nlattr **tb,
671 bool unicast)
672{
673 struct nlattr *tbb[TCA_BPF_MAX + 1];
674 struct bpf_cb_ctx *info = cookie;
675
676 if (!info || !info->opts)
677 return -EINVAL;
678 if (unicast && info->processed)
679 return -EINVAL;
680 if (!tb[TCA_OPTIONS])
681 return NL_CONT;
682
683 libbpf_nla_parse_nested(tbb, TCA_BPF_MAX, tb[TCA_OPTIONS], NULL);
684 if (!tbb[TCA_BPF_ID])
685 return -EINVAL;
686
687 OPTS_SET(info->opts, prog_id, libbpf_nla_getattr_u32(tbb[TCA_BPF_ID]));
688 OPTS_SET(info->opts, handle, tc->tcm_handle);
689 OPTS_SET(info->opts, priority, TC_H_MAJ(tc->tcm_info) >> 16);
690
691 info->processed = true;
692 return unicast ? NL_NEXT : NL_DONE;
693}
694
695static int get_tc_info(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
696 void *cookie)
697{
698 struct tcmsg *tc = NLMSG_DATA(nh);
699 struct nlattr *tb[TCA_MAX + 1];
700
701 libbpf_nla_parse(tb, TCA_MAX,
702 (struct nlattr *)((void *)tc + NLMSG_ALIGN(sizeof(*tc))),
703 NLMSG_PAYLOAD(nh, sizeof(*tc)), NULL);
704 if (!tb[TCA_KIND])
705 return NL_CONT;
706 return __get_tc_info(cookie, tc, tb, nh->nlmsg_flags & NLM_F_ECHO);
707}
708
709static int tc_add_fd_and_name(struct libbpf_nla_req *req, int fd)
710{
711 struct bpf_prog_info info;
712 __u32 info_len = sizeof(info);
713 char name[256];
714 int len, ret;
715
716 memset(&info, 0, info_len);
717 ret = bpf_prog_get_info_by_fd(fd, &info, &info_len);
718 if (ret < 0)
719 return ret;
720
721 ret = nlattr_add(req, TCA_BPF_FD, &fd, sizeof(fd));
722 if (ret < 0)
723 return ret;
724 len = snprintf(name, sizeof(name), "%s:[%u]", info.name, info.id);
725 if (len < 0)
726 return -errno;
727 if (len >= sizeof(name))
728 return -ENAMETOOLONG;
729 return nlattr_add(req, TCA_BPF_NAME, name, len + 1);
730}
731
732int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts)
733{
734 __u32 protocol, bpf_flags, handle, priority, parent, prog_id, flags;
735 int ret, ifindex, attach_point, prog_fd;
736 struct bpf_cb_ctx info = {};
737 struct libbpf_nla_req req;
738 struct nlattr *nla;
739
740 if (!hook || !opts ||
741 !OPTS_VALID(hook, bpf_tc_hook) ||
742 !OPTS_VALID(opts, bpf_tc_opts))
743 return libbpf_err(-EINVAL);
744
745 ifindex = OPTS_GET(hook, ifindex, 0);
746 parent = OPTS_GET(hook, parent, 0);
747 attach_point = OPTS_GET(hook, attach_point, 0);
748
749 handle = OPTS_GET(opts, handle, 0);
750 priority = OPTS_GET(opts, priority, 0);
751 prog_fd = OPTS_GET(opts, prog_fd, 0);
752 prog_id = OPTS_GET(opts, prog_id, 0);
753 flags = OPTS_GET(opts, flags, 0);
754
755 if (ifindex <= 0 || !prog_fd || prog_id)
756 return libbpf_err(-EINVAL);
757 if (priority > UINT16_MAX)
758 return libbpf_err(-EINVAL);
759 if (flags & ~BPF_TC_F_REPLACE)
760 return libbpf_err(-EINVAL);
761
762 flags = (flags & BPF_TC_F_REPLACE) ? NLM_F_REPLACE : NLM_F_EXCL;
763 protocol = ETH_P_ALL;
764
765 memset(&req, 0, sizeof(req));
766 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
767 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE |
768 NLM_F_ECHO | flags;
769 req.nh.nlmsg_type = RTM_NEWTFILTER;
770 req.tc.tcm_family = AF_UNSPEC;
771 req.tc.tcm_ifindex = ifindex;
772 req.tc.tcm_handle = handle;
773 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));
774
775 ret = tc_get_tcm_parent(attach_point, &parent);
776 if (ret < 0)
777 return libbpf_err(ret);
778 req.tc.tcm_parent = parent;
779
780 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));
781 if (ret < 0)
782 return libbpf_err(ret);
783 nla = nlattr_begin_nested(&req, TCA_OPTIONS);
784 if (!nla)
785 return libbpf_err(-EMSGSIZE);
786 ret = tc_add_fd_and_name(&req, prog_fd);
787 if (ret < 0)
788 return libbpf_err(ret);
789 bpf_flags = TCA_BPF_FLAG_ACT_DIRECT;
790 ret = nlattr_add(&req, TCA_BPF_FLAGS, &bpf_flags, sizeof(bpf_flags));
791 if (ret < 0)
792 return libbpf_err(ret);
793 nlattr_end_nested(&req, nla);
794
795 info.opts = opts;
796
797 ret = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, get_tc_info, NULL,
798 &info);
799 if (ret < 0)
800 return libbpf_err(ret);
801 if (!info.processed)
802 return libbpf_err(-ENOENT);
803 return ret;
804}
805
806static int __bpf_tc_detach(const struct bpf_tc_hook *hook,
807 const struct bpf_tc_opts *opts,
808 const bool flush)
809{
810 __u32 protocol = 0, handle, priority, parent, prog_id, flags;
811 int ret, ifindex, attach_point, prog_fd;
812 struct libbpf_nla_req req;
813
814 if (!hook ||
815 !OPTS_VALID(hook, bpf_tc_hook) ||
816 !OPTS_VALID(opts, bpf_tc_opts))
817 return -EINVAL;
818
819 ifindex = OPTS_GET(hook, ifindex, 0);
820 parent = OPTS_GET(hook, parent, 0);
821 attach_point = OPTS_GET(hook, attach_point, 0);
822
823 handle = OPTS_GET(opts, handle, 0);
824 priority = OPTS_GET(opts, priority, 0);
825 prog_fd = OPTS_GET(opts, prog_fd, 0);
826 prog_id = OPTS_GET(opts, prog_id, 0);
827 flags = OPTS_GET(opts, flags, 0);
828
829 if (ifindex <= 0 || flags || prog_fd || prog_id)
830 return -EINVAL;
831 if (priority > UINT16_MAX)
832 return -EINVAL;
833 if (!flush) {
834 if (!handle || !priority)
835 return -EINVAL;
836 protocol = ETH_P_ALL;
837 } else {
838 if (handle || priority)
839 return -EINVAL;
840 }
841
842 memset(&req, 0, sizeof(req));
843 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
844 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
845 req.nh.nlmsg_type = RTM_DELTFILTER;
846 req.tc.tcm_family = AF_UNSPEC;
847 req.tc.tcm_ifindex = ifindex;
848 if (!flush) {
849 req.tc.tcm_handle = handle;
850 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));
851 }
852
853 ret = tc_get_tcm_parent(attach_point, &parent);
854 if (ret < 0)
855 return ret;
856 req.tc.tcm_parent = parent;
857
858 if (!flush) {
859 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));
860 if (ret < 0)
861 return ret;
862 }
863
864 return libbpf_netlink_send_recv(&req, NETLINK_ROUTE, NULL, NULL, NULL);
865}
866
867int bpf_tc_detach(const struct bpf_tc_hook *hook,
868 const struct bpf_tc_opts *opts)
869{
870 int ret;
871
872 if (!opts)
873 return libbpf_err(-EINVAL);
874
875 ret = __bpf_tc_detach(hook, opts, false);
876 return libbpf_err(ret);
877}
878
879int bpf_tc_query(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts)
880{
881 __u32 protocol, handle, priority, parent, prog_id, flags;
882 int ret, ifindex, attach_point, prog_fd;
883 struct bpf_cb_ctx info = {};
884 struct libbpf_nla_req req;
885
886 if (!hook || !opts ||
887 !OPTS_VALID(hook, bpf_tc_hook) ||
888 !OPTS_VALID(opts, bpf_tc_opts))
889 return libbpf_err(-EINVAL);
890
891 ifindex = OPTS_GET(hook, ifindex, 0);
892 parent = OPTS_GET(hook, parent, 0);
893 attach_point = OPTS_GET(hook, attach_point, 0);
894
895 handle = OPTS_GET(opts, handle, 0);
896 priority = OPTS_GET(opts, priority, 0);
897 prog_fd = OPTS_GET(opts, prog_fd, 0);
898 prog_id = OPTS_GET(opts, prog_id, 0);
899 flags = OPTS_GET(opts, flags, 0);
900
901 if (ifindex <= 0 || flags || prog_fd || prog_id ||
902 !handle || !priority)
903 return libbpf_err(-EINVAL);
904 if (priority > UINT16_MAX)
905 return libbpf_err(-EINVAL);
906
907 protocol = ETH_P_ALL;
908
909 memset(&req, 0, sizeof(req));
910 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
911 req.nh.nlmsg_flags = NLM_F_REQUEST;
912 req.nh.nlmsg_type = RTM_GETTFILTER;
913 req.tc.tcm_family = AF_UNSPEC;
914 req.tc.tcm_ifindex = ifindex;
915 req.tc.tcm_handle = handle;
916 req.tc.tcm_info = TC_H_MAKE(priority << 16, htons(protocol));
917
918 ret = tc_get_tcm_parent(attach_point, &parent);
919 if (ret < 0)
920 return libbpf_err(ret);
921 req.tc.tcm_parent = parent;
922
923 ret = nlattr_add(&req, TCA_KIND, "bpf", sizeof("bpf"));
924 if (ret < 0)
925 return libbpf_err(ret);
926
927 info.opts = opts;
928
929 ret = libbpf_netlink_send_recv(&req, NETLINK_ROUTE, get_tc_info, NULL,
930 &info);
931 if (ret < 0)
932 return libbpf_err(ret);
933 if (!info.processed)
934 return libbpf_err(-ENOENT);
935 return ret;
936}