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, int protocol)
39 memset(rth, 0, sizeof(rth));
41 rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
43 perror("Cannot open netlink socket");
47 if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) {
52 if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) {
57 memset(&rth->local, 0, sizeof(rth->local));
58 rth->local.nl_family = AF_NETLINK;
59 rth->local.nl_groups = subscriptions;
61 if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
62 perror("Cannot bind netlink socket");
65 addr_len = sizeof(rth->local);
66 if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
67 perror("Cannot getsockname");
70 if (addr_len != sizeof(rth->local)) {
71 fprintf(stderr, "Wrong address length %d\n", addr_len);
74 if (rth->local.nl_family != AF_NETLINK) {
75 fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
78 rth->seq = time(NULL);
82 int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
84 return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
87 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
93 struct sockaddr_nl nladdr;
95 memset(&nladdr, 0, sizeof(nladdr));
96 nladdr.nl_family = AF_NETLINK;
98 req.nlh.nlmsg_len = sizeof(req);
99 req.nlh.nlmsg_type = type;
100 req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
101 req.nlh.nlmsg_pid = 0;
102 req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
103 req.g.rtgen_family = family;
105 return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
108 int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
110 struct sockaddr_nl nladdr;
112 memset(&nladdr, 0, sizeof(nladdr));
113 nladdr.nl_family = AF_NETLINK;
115 return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr));
118 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
121 struct sockaddr_nl nladdr;
122 struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } };
123 struct msghdr msg = {
124 (void*)&nladdr, sizeof(nladdr),
130 memset(&nladdr, 0, sizeof(nladdr));
131 nladdr.nl_family = AF_NETLINK;
133 nlh.nlmsg_len = NLMSG_LENGTH(len);
134 nlh.nlmsg_type = type;
135 nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
137 nlh.nlmsg_seq = rth->dump = ++rth->seq;
139 return sendmsg(rth->fd, &msg, 0);
142 int rtnl_dump_filter(struct rtnl_handle *rth,
143 rtnl_filter_t filter,
149 struct sockaddr_nl nladdr;
150 struct iovec iov = { buf, sizeof(buf) };
156 struct msghdr msg = {
157 (void*)&nladdr, sizeof(nladdr),
163 status = recvmsg(rth->fd, &msg, 0);
172 fprintf(stderr, "EOF on netlink\n");
175 if (msg.msg_namelen != sizeof(nladdr)) {
176 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
180 h = (struct nlmsghdr*)buf;
181 while (NLMSG_OK(h, status)) {
184 if (nladdr.nl_pid != 0 ||
185 h->nlmsg_pid != rth->local.nl_pid ||
186 h->nlmsg_seq != rth->dump) {
188 err = junk(&nladdr, h, arg2);
195 if (h->nlmsg_type == NLMSG_DONE)
197 if (h->nlmsg_type == NLMSG_ERROR) {
198 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
199 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
200 fprintf(stderr, "ERROR truncated\n");
203 perror("RTNETLINK answers");
207 err = filter(&nladdr, h, arg1);
212 h = NLMSG_NEXT(h, status);
214 if (msg.msg_flags & MSG_TRUNC) {
215 fprintf(stderr, "Message truncated\n");
219 fprintf(stderr, "!!!Remnant of size %d\n", status);
225 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
226 unsigned groups, struct nlmsghdr *answer,
233 struct sockaddr_nl nladdr;
234 struct iovec iov = { (void*)n, n->nlmsg_len };
236 struct msghdr msg = {
237 (void*)&nladdr, sizeof(nladdr),
243 memset(&nladdr, 0, sizeof(nladdr));
244 nladdr.nl_family = AF_NETLINK;
245 nladdr.nl_pid = peer;
246 nladdr.nl_groups = groups;
248 n->nlmsg_seq = seq = ++rtnl->seq;
251 n->nlmsg_flags |= NLM_F_ACK;
253 status = sendmsg(rtnl->fd, &msg, 0);
256 perror("Cannot talk to rtnetlink");
260 memset(buf,0,sizeof(buf));
265 iov.iov_len = sizeof(buf);
266 status = recvmsg(rtnl->fd, &msg, 0);
275 fprintf(stderr, "EOF on netlink\n");
278 if (msg.msg_namelen != sizeof(nladdr)) {
279 fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
282 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
284 int len = h->nlmsg_len;
285 int l = len - sizeof(*h);
287 if (l<0 || len>status) {
288 if (msg.msg_flags & MSG_TRUNC) {
289 fprintf(stderr, "Truncated message\n");
292 fprintf(stderr, "!!!malformed message: len=%d\n", len);
296 if (nladdr.nl_pid != peer ||
297 h->nlmsg_pid != rtnl->local.nl_pid ||
298 h->nlmsg_seq != seq) {
300 err = junk(&nladdr, h, jarg);
307 if (h->nlmsg_type == NLMSG_ERROR) {
308 struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
309 if (l < sizeof(struct nlmsgerr)) {
310 fprintf(stderr, "ERROR truncated\n");
315 memcpy(answer, h, h->nlmsg_len);
318 perror("RTNETLINK answers");
323 memcpy(answer, h, h->nlmsg_len);
327 fprintf(stderr, "Unexpected reply!!!\n");
329 status -= NLMSG_ALIGN(len);
330 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
332 if (msg.msg_flags & MSG_TRUNC) {
333 fprintf(stderr, "Message truncated\n");
337 fprintf(stderr, "!!!Remnant of size %d\n", status);
343 int rtnl_listen(struct rtnl_handle *rtnl,
344 rtnl_filter_t handler,
349 struct sockaddr_nl nladdr;
352 struct msghdr msg = {
353 (void*)&nladdr, sizeof(nladdr),
359 memset(&nladdr, 0, sizeof(nladdr));
360 nladdr.nl_family = AF_NETLINK;
362 nladdr.nl_groups = 0;
368 iov.iov_len = sizeof(buf);
369 status = recvmsg(rtnl->fd, &msg, 0);
378 fprintf(stderr, "EOF on netlink\n");
381 if (msg.msg_namelen != sizeof(nladdr)) {
382 fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
385 for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
387 int len = h->nlmsg_len;
388 int l = len - sizeof(*h);
390 if (l<0 || len>status) {
391 if (msg.msg_flags & MSG_TRUNC) {
392 fprintf(stderr, "Truncated message\n");
395 fprintf(stderr, "!!!malformed message: len=%d\n", len);
399 err = handler(&nladdr, h, jarg);
403 status -= NLMSG_ALIGN(len);
404 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
406 if (msg.msg_flags & MSG_TRUNC) {
407 fprintf(stderr, "Message truncated\n");
411 fprintf(stderr, "!!!Remnant of size %d\n", status);
417 int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
421 struct sockaddr_nl nladdr;
423 struct nlmsghdr *h = (void*)buf;
425 memset(&nladdr, 0, sizeof(nladdr));
426 nladdr.nl_family = AF_NETLINK;
428 nladdr.nl_groups = 0;
434 status = fread(&buf, 1, sizeof(*h), rtnl);
439 perror("rtnl_from_file: fread");
447 l = len - sizeof(*h);
449 if (l<0 || len>sizeof(buf)) {
450 fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
455 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
458 perror("rtnl_from_file: fread");
462 fprintf(stderr, "rtnl-from_file: truncated message\n");
466 err = handler(&nladdr, h, jarg);
472 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
474 int len = RTA_LENGTH(4);
476 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
477 fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
481 rta->rta_type = type;
483 memcpy(RTA_DATA(rta), &data, 4);
484 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
488 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
491 int len = RTA_LENGTH(alen);
494 if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
495 fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
499 rta->rta_type = type;
501 memcpy(RTA_DATA(rta), data, alen);
502 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
506 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
508 if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
509 fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
513 memcpy(NLMSG_TAIL(n), data, len);
514 memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
515 n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
519 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
521 int len = RTA_LENGTH(4);
522 struct rtattr *subrta;
524 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
525 fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
528 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
529 subrta->rta_type = type;
530 subrta->rta_len = len;
531 memcpy(RTA_DATA(subrta), &data, 4);
532 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
536 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
537 const void *data, int alen)
539 struct rtattr *subrta;
540 int len = RTA_LENGTH(alen);
542 if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
543 fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
546 subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
547 subrta->rta_type = type;
548 subrta->rta_len = len;
549 memcpy(RTA_DATA(subrta), data, alen);
550 rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
554 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
556 memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
557 while (RTA_OK(rta, len)) {
558 if (rta->rta_type <= max)
559 tb[rta->rta_type] = rta;
560 rta = RTA_NEXT(rta,len);
563 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
567 int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
571 memset(tb, 0, sizeof(struct rtattr *) * max);
572 while (RTA_OK(rta, len)) {
573 if (rta->rta_type <= max && i < max)
575 rta = RTA_NEXT(rta,len);
578 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);