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