2 * libnetlink.c RTnetlink service routines.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
18 #include <net/if_arp.h>
19 #include <sys/socket.h>
20 #include <netinet/in.h>
26 #include "libnetlink.h"
28 void rtnl_close(struct rtnl_handle *rth)
33 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
40 memset(rth, 0, sizeof(rth));
42 rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
44 perror("Cannot open netlink socket");
48 if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) {
53 if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) {
58 memset(&rth->local, 0, sizeof(rth->local));
59 rth->local.nl_family = AF_NETLINK;
60 rth->local.nl_groups = subscriptions;
62 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
63 perror("Cannot bind netlink socket");
66 addr_len = sizeof(rth->local);
67 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
68 perror("Cannot getsockname");
71 if (addr_len != sizeof(rth->local)) {
72 fprintf(stderr, "Wrong address length %d\n", addr_len);
75 if (rth->local.nl_family != AF_NETLINK) {
76 fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
79 rth->seq = time(NULL);
83 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
85 return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
88 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
94 struct sockaddr_nl nladdr;
96 memset(&nladdr, 0, sizeof(nladdr));
97 nladdr.nl_family = AF_NETLINK;
99 memset(&req, 0, sizeof(req));
100 req.nlh.nlmsg_len = sizeof(req);
101 req.nlh.nlmsg_type = type;
102 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
103 req.nlh.nlmsg_pid = 0;
104 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
105 req.g.rtgen_family = family;
107 return sendto(rth->fd, (void*)&req, sizeof(req), 0,
108 (struct sockaddr*)&nladdr, sizeof(nladdr));
111 int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
113 struct sockaddr_nl nladdr;
115 memset(&nladdr, 0, sizeof(nladdr));
116 nladdr.nl_family = AF_NETLINK;
118 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
121 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
124 struct sockaddr_nl nladdr;
125 struct iovec iov[2] = {
126 { .iov_base = &nlh, .iov_len = sizeof(nlh) },
127 { .iov_base = req, .iov_len = len }
129 struct msghdr msg = {
131 .msg_namelen = sizeof(nladdr),
136 memset(&nladdr, 0, sizeof(nladdr));
137 nladdr.nl_family = AF_NETLINK;
139 nlh.nlmsg_len = NLMSG_LENGTH(len);
140 nlh.nlmsg_type = type;
141 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
143 nlh.nlmsg_seq = rth->dump = ++rth->seq;
145 return sendmsg(rth->fd, &msg, 0);
148 int rtnl_dump_filter(struct rtnl_handle *rth,
149 rtnl_filter_t filter,
154 struct sockaddr_nl nladdr;
156 struct msghdr msg = {
158 .msg_namelen = sizeof(nladdr),
169 iov.iov_len = sizeof(buf);
170 status = recvmsg(rth->fd, &msg, 0);
180 fprintf(stderr, "EOF on netlink\n");
184 h = (struct nlmsghdr*)buf;
185 while (NLMSG_OK(h, status)) {
188 if (nladdr.nl_pid != 0 ||
189 h->nlmsg_pid != rth->local.nl_pid ||
190 h->nlmsg_seq != rth->dump) {
192 err = junk(&nladdr, h, arg2);
199 if (h->nlmsg_type == NLMSG_DONE)
201 if (h->nlmsg_type == NLMSG_ERROR) {
202 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
203 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
204 fprintf(stderr, "ERROR truncated\n");
207 perror("RTNETLINK answers");
211 err = filter(&nladdr, h, arg1);
216 h = NLMSG_NEXT(h, status);
218 if (msg.msg_flags & MSG_TRUNC) {
219 fprintf(stderr, "Message truncated\n");
223 fprintf(stderr, "!!!Remnant of size %d\n", status);
229 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
230 unsigned groups, struct nlmsghdr *answer,
237 struct sockaddr_nl nladdr;
239 .iov_base = (void*) n,
240 .iov_len = n->nlmsg_len
242 struct msghdr msg = {
244 .msg_namelen = sizeof(nladdr),
250 memset(&nladdr, 0, sizeof(nladdr));
251 nladdr.nl_family = AF_NETLINK;
252 nladdr.nl_pid = peer;
253 nladdr.nl_groups = groups;
255 n->nlmsg_seq = seq = ++rtnl->seq;
258 n->nlmsg_flags |= NLM_F_ACK;
260 status = sendmsg(rtnl->fd, &msg, 0);
263 perror("Cannot talk to rtnetlink");
267 memset(buf,0,sizeof(buf));
272 iov.iov_len = sizeof(buf);
273 status = recvmsg(rtnl->fd, &msg, 0);
282 fprintf(stderr, "EOF on netlink\n");
285 if (msg.msg_namelen != sizeof(nladdr)) {
286 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
289 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
291 int len = h->nlmsg_len;
292 int l = len - sizeof(*h);
294 if (l<0 || len>status) {
295 if (msg.msg_flags & MSG_TRUNC) {
296 fprintf(stderr, "Truncated message\n");
299 fprintf(stderr, "!!!malformed message: len=%d\n", len);
303 if (nladdr.nl_pid != peer ||
304 h->nlmsg_pid != rtnl->local.nl_pid ||
305 h->nlmsg_seq != seq) {
307 err = junk(&nladdr, h, jarg);
311 /* Don't forget to skip that message. */
312 status -= NLMSG_ALIGN(len);
313 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
317 if (h->nlmsg_type == NLMSG_ERROR) {
318 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
319 if (l < sizeof(struct nlmsgerr)) {
320 fprintf(stderr, "ERROR truncated\n");
325 memcpy(answer, h, h->nlmsg_len);
328 perror("RTNETLINK answers");
333 memcpy(answer, h, h->nlmsg_len);
337 fprintf(stderr, "Unexpected reply!!!\n");
339 status -= NLMSG_ALIGN(len);
340 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
342 if (msg.msg_flags & MSG_TRUNC) {
343 fprintf(stderr, "Message truncated\n");
347 fprintf(stderr, "!!!Remnant of size %d\n", status);
353 int rtnl_listen(struct rtnl_handle *rtnl,
354 rtnl_filter_t handler,
359 struct sockaddr_nl nladdr;
361 struct msghdr msg = {
363 .msg_namelen = sizeof(nladdr),
369 memset(&nladdr, 0, sizeof(nladdr));
370 nladdr.nl_family = AF_NETLINK;
372 nladdr.nl_groups = 0;
376 iov.iov_len = sizeof(buf);
377 status = recvmsg(rtnl->fd, &msg, 0);
386 fprintf(stderr, "EOF on netlink\n");
389 if (msg.msg_namelen != sizeof(nladdr)) {
390 fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
393 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
395 int len = h->nlmsg_len;
396 int l = len - sizeof(*h);
398 if (l<0 || len>status) {
399 if (msg.msg_flags & MSG_TRUNC) {
400 fprintf(stderr, "Truncated message\n");
403 fprintf(stderr, "!!!malformed message: len=%d\n", len);
407 err = handler(&nladdr, h, jarg);
411 status -= NLMSG_ALIGN(len);
412 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
414 if (msg.msg_flags & MSG_TRUNC) {
415 fprintf(stderr, "Message truncated\n");
419 fprintf(stderr, "!!!Remnant of size %d\n", status);
425 int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
429 struct sockaddr_nl nladdr;
431 struct nlmsghdr *h = (void*)buf;
433 memset(&nladdr, 0, sizeof(nladdr));
434 nladdr.nl_family = AF_NETLINK;
436 nladdr.nl_groups = 0;
442 status = fread(&buf, 1, sizeof(*h), rtnl);
447 perror("rtnl_from_file: fread");
455 l = len - sizeof(*h);
457 if (l<0 || len>sizeof(buf)) {
458 fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
463 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
466 perror("rtnl_from_file: fread");
470 fprintf(stderr, "rtnl-from_file: truncated message\n");
474 err = handler(&nladdr, h, jarg);
480 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
482 int len = RTA_LENGTH(4);
484 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
485 fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
489 rta->rta_type = type;
491 memcpy(RTA_DATA(rta), &data, 4);
492 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
496 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
499 int len = RTA_LENGTH(alen);
502 if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
503 fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
507 rta->rta_type = type;
509 memcpy(RTA_DATA(rta), data, alen);
510 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
514 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
516 if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
517 fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
521 memcpy(NLMSG_TAIL(n), data, len);
522 memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
523 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
527 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
529 int len = RTA_LENGTH(4);
530 struct rtattr *subrta;
532 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
533 fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
536 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
537 subrta->rta_type = type;
538 subrta->rta_len = len;
539 memcpy(RTA_DATA(subrta), &data, 4);
540 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
544 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
545 const void *data, int alen)
547 struct rtattr *subrta;
548 int len = RTA_LENGTH(alen);
550 if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
551 fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
554 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
555 subrta->rta_type = type;
556 subrta->rta_len = len;
557 memcpy(RTA_DATA(subrta), data, alen);
558 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
562 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
564 memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
565 while (RTA_OK(rta, len)) {
566 if (rta->rta_type <= max)
567 tb[rta->rta_type] = rta;
568 rta = RTA_NEXT(rta,len);
571 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
575 int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
579 memset(tb, 0, sizeof(struct rtattr *) * max);
580 while (RTA_OK(rta, len)) {
581 if (rta->rta_type <= max && i < max)
583 rta = RTA_NEXT(rta,len);
586 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);