Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2/* Copyright (c) 2018 Facebook */
3
4#include <stdlib.h>
5#include <memory.h>
6#include <unistd.h>
7#include <linux/bpf.h>
8#include <linux/rtnetlink.h>
9#include <sys/socket.h>
10#include <errno.h>
11#include <time.h>
12
13#include "bpf.h"
14#include "libbpf.h"
15#include "libbpf_internal.h"
16#include "nlattr.h"
17
18/* make sure libbpf doesn't use kernel-only integer typedefs */
19#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
20
21#ifndef SOL_NETLINK
22#define SOL_NETLINK 270
23#endif
24
25typedef int (*__dump_nlmsg_t)(struct nlmsghdr *nlmsg, libbpf_dump_nlmsg_t,
26 void *cookie);
27
28struct xdp_id_md {
29 int ifindex;
30 __u32 flags;
31 struct xdp_link_info info;
32};
33
34int libbpf_netlink_open(__u32 *nl_pid)
35{
36 struct sockaddr_nl sa;
37 socklen_t addrlen;
38 int one = 1, ret;
39 int sock;
40
41 memset(&sa, 0, sizeof(sa));
42 sa.nl_family = AF_NETLINK;
43
44 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
45 if (sock < 0)
46 return -errno;
47
48 if (setsockopt(sock, SOL_NETLINK, NETLINK_EXT_ACK,
49 &one, sizeof(one)) < 0) {
50 pr_warn("Netlink error reporting not supported\n");
51 }
52
53 if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
54 ret = -errno;
55 goto cleanup;
56 }
57
58 addrlen = sizeof(sa);
59 if (getsockname(sock, (struct sockaddr *)&sa, &addrlen) < 0) {
60 ret = -errno;
61 goto cleanup;
62 }
63
64 if (addrlen != sizeof(sa)) {
65 ret = -LIBBPF_ERRNO__INTERNAL;
66 goto cleanup;
67 }
68
69 *nl_pid = sa.nl_pid;
70 return sock;
71
72cleanup:
73 close(sock);
74 return ret;
75}
76
77static int bpf_netlink_recv(int sock, __u32 nl_pid, int seq,
78 __dump_nlmsg_t _fn, libbpf_dump_nlmsg_t fn,
79 void *cookie)
80{
81 bool multipart = true;
82 struct nlmsgerr *err;
83 struct nlmsghdr *nh;
84 char buf[4096];
85 int len, ret;
86
87 while (multipart) {
88 multipart = false;
89 len = recv(sock, buf, sizeof(buf), 0);
90 if (len < 0) {
91 ret = -errno;
92 goto done;
93 }
94
95 if (len == 0)
96 break;
97
98 for (nh = (struct nlmsghdr *)buf; NLMSG_OK(nh, len);
99 nh = NLMSG_NEXT(nh, len)) {
100 if (nh->nlmsg_pid != nl_pid) {
101 ret = -LIBBPF_ERRNO__WRNGPID;
102 goto done;
103 }
104 if (nh->nlmsg_seq != seq) {
105 ret = -LIBBPF_ERRNO__INVSEQ;
106 goto done;
107 }
108 if (nh->nlmsg_flags & NLM_F_MULTI)
109 multipart = true;
110 switch (nh->nlmsg_type) {
111 case NLMSG_ERROR:
112 err = (struct nlmsgerr *)NLMSG_DATA(nh);
113 if (!err->error)
114 continue;
115 ret = err->error;
116 libbpf_nla_dump_errormsg(nh);
117 goto done;
118 case NLMSG_DONE:
119 return 0;
120 default:
121 break;
122 }
123 if (_fn) {
124 ret = _fn(nh, fn, cookie);
125 if (ret)
126 return ret;
127 }
128 }
129 }
130 ret = 0;
131done:
132 return ret;
133}
134
135int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags)
136{
137 int sock, seq = 0, ret;
138 struct nlattr *nla, *nla_xdp;
139 struct {
140 struct nlmsghdr nh;
141 struct ifinfomsg ifinfo;
142 char attrbuf[64];
143 } req;
144 __u32 nl_pid;
145
146 sock = libbpf_netlink_open(&nl_pid);
147 if (sock < 0)
148 return sock;
149
150 memset(&req, 0, sizeof(req));
151 req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
152 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
153 req.nh.nlmsg_type = RTM_SETLINK;
154 req.nh.nlmsg_pid = 0;
155 req.nh.nlmsg_seq = ++seq;
156 req.ifinfo.ifi_family = AF_UNSPEC;
157 req.ifinfo.ifi_index = ifindex;
158
159 /* started nested attribute for XDP */
160 nla = (struct nlattr *)(((char *)&req)
161 + NLMSG_ALIGN(req.nh.nlmsg_len));
162 nla->nla_type = NLA_F_NESTED | IFLA_XDP;
163 nla->nla_len = NLA_HDRLEN;
164
165 /* add XDP fd */
166 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
167 nla_xdp->nla_type = IFLA_XDP_FD;
168 nla_xdp->nla_len = NLA_HDRLEN + sizeof(int);
169 memcpy((char *)nla_xdp + NLA_HDRLEN, &fd, sizeof(fd));
170 nla->nla_len += nla_xdp->nla_len;
171
172 /* if user passed in any flags, add those too */
173 if (flags) {
174 nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len);
175 nla_xdp->nla_type = IFLA_XDP_FLAGS;
176 nla_xdp->nla_len = NLA_HDRLEN + sizeof(flags);
177 memcpy((char *)nla_xdp + NLA_HDRLEN, &flags, sizeof(flags));
178 nla->nla_len += nla_xdp->nla_len;
179 }
180
181 req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len);
182
183 if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) {
184 ret = -errno;
185 goto cleanup;
186 }
187 ret = bpf_netlink_recv(sock, nl_pid, seq, NULL, NULL, NULL);
188
189cleanup:
190 close(sock);
191 return ret;
192}
193
194static int __dump_link_nlmsg(struct nlmsghdr *nlh,
195 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
196{
197 struct nlattr *tb[IFLA_MAX + 1], *attr;
198 struct ifinfomsg *ifi = NLMSG_DATA(nlh);
199 int len;
200
201 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifi));
202 attr = (struct nlattr *) ((void *) ifi + NLMSG_ALIGN(sizeof(*ifi)));
203 if (libbpf_nla_parse(tb, IFLA_MAX, attr, len, NULL) != 0)
204 return -LIBBPF_ERRNO__NLPARSE;
205
206 return dump_link_nlmsg(cookie, ifi, tb);
207}
208
209static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb)
210{
211 struct nlattr *xdp_tb[IFLA_XDP_MAX + 1];
212 struct xdp_id_md *xdp_id = cookie;
213 struct ifinfomsg *ifinfo = msg;
214 int ret;
215
216 if (xdp_id->ifindex && xdp_id->ifindex != ifinfo->ifi_index)
217 return 0;
218
219 if (!tb[IFLA_XDP])
220 return 0;
221
222 ret = libbpf_nla_parse_nested(xdp_tb, IFLA_XDP_MAX, tb[IFLA_XDP], NULL);
223 if (ret)
224 return ret;
225
226 if (!xdp_tb[IFLA_XDP_ATTACHED])
227 return 0;
228
229 xdp_id->info.attach_mode = libbpf_nla_getattr_u8(
230 xdp_tb[IFLA_XDP_ATTACHED]);
231
232 if (xdp_id->info.attach_mode == XDP_ATTACHED_NONE)
233 return 0;
234
235 if (xdp_tb[IFLA_XDP_PROG_ID])
236 xdp_id->info.prog_id = libbpf_nla_getattr_u32(
237 xdp_tb[IFLA_XDP_PROG_ID]);
238
239 if (xdp_tb[IFLA_XDP_SKB_PROG_ID])
240 xdp_id->info.skb_prog_id = libbpf_nla_getattr_u32(
241 xdp_tb[IFLA_XDP_SKB_PROG_ID]);
242
243 if (xdp_tb[IFLA_XDP_DRV_PROG_ID])
244 xdp_id->info.drv_prog_id = libbpf_nla_getattr_u32(
245 xdp_tb[IFLA_XDP_DRV_PROG_ID]);
246
247 if (xdp_tb[IFLA_XDP_HW_PROG_ID])
248 xdp_id->info.hw_prog_id = libbpf_nla_getattr_u32(
249 xdp_tb[IFLA_XDP_HW_PROG_ID]);
250
251 return 0;
252}
253
254int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
255 size_t info_size, __u32 flags)
256{
257 struct xdp_id_md xdp_id = {};
258 int sock, ret;
259 __u32 nl_pid;
260 __u32 mask;
261
262 if (flags & ~XDP_FLAGS_MASK || !info_size)
263 return -EINVAL;
264
265 /* Check whether the single {HW,DRV,SKB} mode is set */
266 flags &= (XDP_FLAGS_SKB_MODE | XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE);
267 mask = flags - 1;
268 if (flags && flags & mask)
269 return -EINVAL;
270
271 sock = libbpf_netlink_open(&nl_pid);
272 if (sock < 0)
273 return sock;
274
275 xdp_id.ifindex = ifindex;
276 xdp_id.flags = flags;
277
278 ret = libbpf_nl_get_link(sock, nl_pid, get_xdp_info, &xdp_id);
279 if (!ret) {
280 size_t sz = min(info_size, sizeof(xdp_id.info));
281
282 memcpy(info, &xdp_id.info, sz);
283 memset((void *) info + sz, 0, info_size - sz);
284 }
285
286 close(sock);
287 return ret;
288}
289
290static __u32 get_xdp_id(struct xdp_link_info *info, __u32 flags)
291{
292 if (info->attach_mode != XDP_ATTACHED_MULTI)
293 return info->prog_id;
294 if (flags & XDP_FLAGS_DRV_MODE)
295 return info->drv_prog_id;
296 if (flags & XDP_FLAGS_HW_MODE)
297 return info->hw_prog_id;
298 if (flags & XDP_FLAGS_SKB_MODE)
299 return info->skb_prog_id;
300
301 return 0;
302}
303
304int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags)
305{
306 struct xdp_link_info info;
307 int ret;
308
309 ret = bpf_get_link_xdp_info(ifindex, &info, sizeof(info), flags);
310 if (!ret)
311 *prog_id = get_xdp_id(&info, flags);
312
313 return ret;
314}
315
316int libbpf_nl_get_link(int sock, unsigned int nl_pid,
317 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie)
318{
319 struct {
320 struct nlmsghdr nlh;
321 struct ifinfomsg ifm;
322 } req = {
323 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
324 .nlh.nlmsg_type = RTM_GETLINK,
325 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
326 .ifm.ifi_family = AF_PACKET,
327 };
328 int seq = time(NULL);
329
330 req.nlh.nlmsg_seq = seq;
331 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
332 return -errno;
333
334 return bpf_netlink_recv(sock, nl_pid, seq, __dump_link_nlmsg,
335 dump_link_nlmsg, cookie);
336}
337
338static int __dump_class_nlmsg(struct nlmsghdr *nlh,
339 libbpf_dump_nlmsg_t dump_class_nlmsg,
340 void *cookie)
341{
342 struct nlattr *tb[TCA_MAX + 1], *attr;
343 struct tcmsg *t = NLMSG_DATA(nlh);
344 int len;
345
346 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
347 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
348 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
349 return -LIBBPF_ERRNO__NLPARSE;
350
351 return dump_class_nlmsg(cookie, t, tb);
352}
353
354int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
355 libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie)
356{
357 struct {
358 struct nlmsghdr nlh;
359 struct tcmsg t;
360 } req = {
361 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
362 .nlh.nlmsg_type = RTM_GETTCLASS,
363 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
364 .t.tcm_family = AF_UNSPEC,
365 .t.tcm_ifindex = ifindex,
366 };
367 int seq = time(NULL);
368
369 req.nlh.nlmsg_seq = seq;
370 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
371 return -errno;
372
373 return bpf_netlink_recv(sock, nl_pid, seq, __dump_class_nlmsg,
374 dump_class_nlmsg, cookie);
375}
376
377static int __dump_qdisc_nlmsg(struct nlmsghdr *nlh,
378 libbpf_dump_nlmsg_t dump_qdisc_nlmsg,
379 void *cookie)
380{
381 struct nlattr *tb[TCA_MAX + 1], *attr;
382 struct tcmsg *t = NLMSG_DATA(nlh);
383 int len;
384
385 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
386 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
387 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
388 return -LIBBPF_ERRNO__NLPARSE;
389
390 return dump_qdisc_nlmsg(cookie, t, tb);
391}
392
393int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
394 libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie)
395{
396 struct {
397 struct nlmsghdr nlh;
398 struct tcmsg t;
399 } req = {
400 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
401 .nlh.nlmsg_type = RTM_GETQDISC,
402 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
403 .t.tcm_family = AF_UNSPEC,
404 .t.tcm_ifindex = ifindex,
405 };
406 int seq = time(NULL);
407
408 req.nlh.nlmsg_seq = seq;
409 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
410 return -errno;
411
412 return bpf_netlink_recv(sock, nl_pid, seq, __dump_qdisc_nlmsg,
413 dump_qdisc_nlmsg, cookie);
414}
415
416static int __dump_filter_nlmsg(struct nlmsghdr *nlh,
417 libbpf_dump_nlmsg_t dump_filter_nlmsg,
418 void *cookie)
419{
420 struct nlattr *tb[TCA_MAX + 1], *attr;
421 struct tcmsg *t = NLMSG_DATA(nlh);
422 int len;
423
424 len = nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*t));
425 attr = (struct nlattr *) ((void *) t + NLMSG_ALIGN(sizeof(*t)));
426 if (libbpf_nla_parse(tb, TCA_MAX, attr, len, NULL) != 0)
427 return -LIBBPF_ERRNO__NLPARSE;
428
429 return dump_filter_nlmsg(cookie, t, tb);
430}
431
432int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
433 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie)
434{
435 struct {
436 struct nlmsghdr nlh;
437 struct tcmsg t;
438 } req = {
439 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
440 .nlh.nlmsg_type = RTM_GETTFILTER,
441 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
442 .t.tcm_family = AF_UNSPEC,
443 .t.tcm_ifindex = ifindex,
444 .t.tcm_parent = handle,
445 };
446 int seq = time(NULL);
447
448 req.nlh.nlmsg_seq = seq;
449 if (send(sock, &req, req.nlh.nlmsg_len, 0) < 0)
450 return -errno;
451
452 return bpf_netlink_recv(sock, nl_pid, seq, __dump_filter_nlmsg,
453 dump_filter_nlmsg, cookie);
454}