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