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);
314 if (h->nlmsg_type == NLMSG_ERROR) {
315 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
316 if (l < sizeof(struct nlmsgerr)) {
317 fprintf(stderr, "ERROR truncated\n");
322 memcpy(answer, h, h->nlmsg_len);
325 perror("RTNETLINK answers");
330 memcpy(answer, h, h->nlmsg_len);
334 fprintf(stderr, "Unexpected reply!!!\n");
336 status -= NLMSG_ALIGN(len);
337 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
339 if (msg.msg_flags & MSG_TRUNC) {
340 fprintf(stderr, "Message truncated\n");
344 fprintf(stderr, "!!!Remnant of size %d\n", status);
350 int rtnl_listen(struct rtnl_handle *rtnl,
351 rtnl_filter_t handler,
356 struct sockaddr_nl nladdr;
358 struct msghdr msg = {
360 .msg_namelen = sizeof(nladdr),
366 memset(&nladdr, 0, sizeof(nladdr));
367 nladdr.nl_family = AF_NETLINK;
369 nladdr.nl_groups = 0;
373 iov.iov_len = sizeof(buf);
374 status = recvmsg(rtnl->fd, &msg, 0);
383 fprintf(stderr, "EOF on netlink\n");
386 if (msg.msg_namelen != sizeof(nladdr)) {
387 fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
390 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
392 int len = h->nlmsg_len;
393 int l = len - sizeof(*h);
395 if (l<0 || len>status) {
396 if (msg.msg_flags & MSG_TRUNC) {
397 fprintf(stderr, "Truncated message\n");
400 fprintf(stderr, "!!!malformed message: len=%d\n", len);
404 err = handler(&nladdr, h, jarg);
408 status -= NLMSG_ALIGN(len);
409 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
411 if (msg.msg_flags & MSG_TRUNC) {
412 fprintf(stderr, "Message truncated\n");
416 fprintf(stderr, "!!!Remnant of size %d\n", status);
422 int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
426 struct sockaddr_nl nladdr;
428 struct nlmsghdr *h = (void*)buf;
430 memset(&nladdr, 0, sizeof(nladdr));
431 nladdr.nl_family = AF_NETLINK;
433 nladdr.nl_groups = 0;
439 status = fread(&buf, 1, sizeof(*h), rtnl);
444 perror("rtnl_from_file: fread");
452 l = len - sizeof(*h);
454 if (l<0 || len>sizeof(buf)) {
455 fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
460 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
463 perror("rtnl_from_file: fread");
467 fprintf(stderr, "rtnl-from_file: truncated message\n");
471 err = handler(&nladdr, h, jarg);
477 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
479 int len = RTA_LENGTH(4);
481 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
482 fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
486 rta->rta_type = type;
488 memcpy(RTA_DATA(rta), &data, 4);
489 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
493 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
496 int len = RTA_LENGTH(alen);
499 if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
500 fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
504 rta->rta_type = type;
506 memcpy(RTA_DATA(rta), data, alen);
507 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
511 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
513 if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
514 fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
518 memcpy(NLMSG_TAIL(n), data, len);
519 memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
520 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
524 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
526 int len = RTA_LENGTH(4);
527 struct rtattr *subrta;
529 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
530 fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
533 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
534 subrta->rta_type = type;
535 subrta->rta_len = len;
536 memcpy(RTA_DATA(subrta), &data, 4);
537 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
541 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
542 const void *data, int alen)
544 struct rtattr *subrta;
545 int len = RTA_LENGTH(alen);
547 if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
548 fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
551 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
552 subrta->rta_type = type;
553 subrta->rta_len = len;
554 memcpy(RTA_DATA(subrta), data, alen);
555 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
559 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
561 memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
562 while (RTA_OK(rta, len)) {
563 if (rta->rta_type <= max)
564 tb[rta->rta_type] = rta;
565 rta = RTA_NEXT(rta,len);
568 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
572 int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
576 memset(tb, 0, sizeof(struct rtattr *) * max);
577 while (RTA_OK(rta, len)) {
578 if (rta->rta_type <= max && i < max)
580 rta = RTA_NEXT(rta,len);
583 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);