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
26 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
27
28 typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
29 void *cookie);
30
31 struct 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
39 struct xdp_id_md {
40 int ifindex;
41 __u32 flags;
42 struct xdp_link_info info;
43 __u64 feature_flags;
44 };
45
46 struct xdp_features_md {
47 int ifindex;
48 __u32 xdp_zc_max_segs;
49 __u64 flags;
50 };
51
libbpf_netlink_open(__u32 * nl_pid,int proto)52 static 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
90 cleanup:
91 close(sock);
92 return ret;
93 }
94
libbpf_netlink_close(int sock)95 static void libbpf_netlink_close(int sock)
96 {
97 close(sock);
98 }
99
100 enum {
101 NL_CONT,
102 NL_NEXT,
103 NL_DONE,
104 };
105
netlink_recvmsg(int sock,struct msghdr * mhdr,int flags)106 static 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
alloc_iov(struct iovec * iov,int len)119 static 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
libbpf_netlink_recv(int sock,__u32 nl_pid,int seq,__dump_nlmsg_t _fn,libbpf_dump_nlmsg_t fn,void * cookie)132 static 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) {
151 start:
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;
217 done:
218 free(iov.iov_base);
219 return ret;
220 }
221
libbpf_netlink_send_recv(struct libbpf_nla_req * req,int proto,__dump_nlmsg_t parse_msg,libbpf_dump_nlmsg_t parse_attr,void * cookie)222 static 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);
244 out:
245 libbpf_netlink_close(sock);
246 return ret;
247 }
248
parse_genl_family_id(struct nlmsghdr * nh,libbpf_dump_nlmsg_t fn,void * cookie)249 static 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
libbpf_netlink_resolve_genl_family_id(const char * name,__u16 len,__u16 * id)266 static 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
__bpf_set_link_xdp_fd_replace(int ifindex,int fd,int old_fd,__u32 flags)286 static 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
bpf_xdp_attach(int ifindex,int prog_fd,__u32 flags,const struct bpf_xdp_attach_opts * opts)322 int 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
bpf_xdp_detach(int ifindex,__u32 flags,const struct bpf_xdp_attach_opts * opts)339 int 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
__dump_link_nlmsg(struct nlmsghdr * nlh,libbpf_dump_nlmsg_t dump_link_nlmsg,void * cookie)344 static 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
get_xdp_info(void * cookie,void * msg,struct nlattr ** tb)360 static 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
parse_xdp_features(struct nlmsghdr * nh,libbpf_dump_nlmsg_t fn,void * cookie)405 static 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
bpf_xdp_query(int ifindex,int xdp_flags,struct bpf_xdp_query_opts * opts)431 int 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
502 skip_feature_flags:
503 return 0;
504 }
505
bpf_xdp_query_id(int ifindex,int flags,__u32 * prog_id)506 int 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
532 typedef int (*qdisc_config_t)(struct libbpf_nla_req *req);
533
clsact_config(struct libbpf_nla_req * req)534 static 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
attach_point_to_config(struct bpf_tc_hook * hook,qdisc_config_t * config)542 static 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
tc_get_tcm_parent(enum bpf_tc_attach_point attach_point,__u32 * parent)560 static 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
tc_qdisc_modify(struct bpf_tc_hook * hook,int cmd,int flags)582 static 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
tc_qdisc_create_excl(struct bpf_tc_hook * hook)606 static 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
tc_qdisc_delete(struct bpf_tc_hook * hook)611 static int tc_qdisc_delete(struct bpf_tc_hook *hook)
612 {
613 return tc_qdisc_modify(hook, RTM_DELQDISC, 0);
614 }
615
bpf_tc_hook_create(struct bpf_tc_hook * hook)616 int 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
628 static int __bpf_tc_detach(const struct bpf_tc_hook *hook,
629 const struct bpf_tc_opts *opts,
630 const bool flush);
631
bpf_tc_hook_destroy(struct bpf_tc_hook * hook)632 int 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
651 struct bpf_cb_ctx {
652 struct bpf_tc_opts *opts;
653 bool processed;
654 };
655
__get_tc_info(void * cookie,struct tcmsg * tc,struct nlattr ** tb,bool unicast)656 static 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
get_tc_info(struct nlmsghdr * nh,libbpf_dump_nlmsg_t fn,void * cookie)681 static 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
tc_add_fd_and_name(struct libbpf_nla_req * req,int fd)695 static 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
bpf_tc_attach(const struct bpf_tc_hook * hook,struct bpf_tc_opts * opts)718 int 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
__bpf_tc_detach(const struct bpf_tc_hook * hook,const struct bpf_tc_opts * opts,const bool flush)792 static 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
bpf_tc_detach(const struct bpf_tc_hook * hook,const struct bpf_tc_opts * opts)853 int 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
bpf_tc_query(const struct bpf_tc_hook * hook,struct bpf_tc_opts * opts)865 int 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 }
923