| /* |
| * libnetlink.c RTnetlink service routines. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <syslog.h> |
| #include <fcntl.h> |
| #include <net/if_arp.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <time.h> |
| #include <sys/uio.h> |
| |
| #include "libnetlink.h" |
| |
| void rtnl_close(struct rtnl_handle *rth) |
| { |
| if (rth->fd >= 0) { |
| close(rth->fd); |
| rth->fd = -1; |
| } |
| } |
| |
| int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions, |
| int protocol) |
| { |
| socklen_t addr_len; |
| int sndbuf = 32768; |
| int rcvbuf = 32768; |
| |
| memset(rth, 0, sizeof(*rth)); |
| |
| rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol); |
| if (rth->fd < 0) { |
| perror("Cannot open netlink socket"); |
| return -1; |
| } |
| |
| if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) { |
| perror("SO_SNDBUF"); |
| return -1; |
| } |
| |
| if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) { |
| perror("SO_RCVBUF"); |
| return -1; |
| } |
| |
| memset(&rth->local, 0, sizeof(rth->local)); |
| rth->local.nl_family = AF_NETLINK; |
| rth->local.nl_groups = subscriptions; |
| |
| if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) { |
| perror("Cannot bind netlink socket"); |
| return -1; |
| } |
| addr_len = sizeof(rth->local); |
| if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) { |
| perror("Cannot getsockname"); |
| return -1; |
| } |
| if (addr_len != sizeof(rth->local)) { |
| fprintf(stderr, "Wrong address length %d\n", addr_len); |
| return -1; |
| } |
| if (rth->local.nl_family != AF_NETLINK) { |
| fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family); |
| return -1; |
| } |
| rth->seq = time(NULL); |
| return 0; |
| } |
| |
| int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions) |
| { |
| return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE); |
| } |
| |
| int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type) |
| { |
| struct { |
| struct nlmsghdr nlh; |
| struct rtgenmsg g; |
| } req; |
| struct sockaddr_nl nladdr; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| |
| memset(&req, 0, sizeof(req)); |
| req.nlh.nlmsg_len = sizeof(req); |
| req.nlh.nlmsg_type = type; |
| req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST; |
| req.nlh.nlmsg_pid = 0; |
| req.nlh.nlmsg_seq = rth->dump = ++rth->seq; |
| req.g.rtgen_family = family; |
| |
| return sendto(rth->fd, (void*)&req, sizeof(req), 0, |
| (struct sockaddr*)&nladdr, sizeof(nladdr)); |
| } |
| |
| int rtnl_send(struct rtnl_handle *rth, const char *buf, int len) |
| { |
| struct sockaddr_nl nladdr; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| |
| return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr)); |
| } |
| |
| int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len) |
| { |
| struct nlmsghdr nlh; |
| struct sockaddr_nl nladdr; |
| struct iovec iov[2] = { |
| { .iov_base = &nlh, .iov_len = sizeof(nlh) }, |
| { .iov_base = req, .iov_len = len } |
| }; |
| struct msghdr msg = { |
| .msg_name = &nladdr, |
| .msg_namelen = sizeof(nladdr), |
| .msg_iov = iov, |
| .msg_iovlen = 2, |
| }; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| |
| nlh.nlmsg_len = NLMSG_LENGTH(len); |
| nlh.nlmsg_type = type; |
| nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST; |
| nlh.nlmsg_pid = 0; |
| nlh.nlmsg_seq = rth->dump = ++rth->seq; |
| |
| return sendmsg(rth->fd, &msg, 0); |
| } |
| |
| int rtnl_dump_filter(struct rtnl_handle *rth, |
| rtnl_filter_t filter, |
| void *arg1, |
| rtnl_filter_t junk, |
| void *arg2) |
| { |
| struct sockaddr_nl nladdr; |
| struct iovec iov; |
| struct msghdr msg = { |
| .msg_name = &nladdr, |
| .msg_namelen = sizeof(nladdr), |
| .msg_iov = &iov, |
| .msg_iovlen = 1, |
| }; |
| char buf[16384]; |
| |
| iov.iov_base = buf; |
| while (1) { |
| int status; |
| struct nlmsghdr *h; |
| |
| iov.iov_len = sizeof(buf); |
| status = recvmsg(rth->fd, &msg, 0); |
| |
| if (status < 0) { |
| if (errno == EINTR || errno == EAGAIN) |
| continue; |
| fprintf(stderr, "netlink receive error %s (%d)\n", |
| strerror(errno), errno); |
| return -1; |
| } |
| |
| if (status == 0) { |
| fprintf(stderr, "EOF on netlink\n"); |
| return -1; |
| } |
| |
| h = (struct nlmsghdr*)buf; |
| while (NLMSG_OK(h, status)) { |
| int err; |
| |
| if (nladdr.nl_pid != 0 || |
| h->nlmsg_pid != rth->local.nl_pid || |
| h->nlmsg_seq != rth->dump) { |
| if (junk) { |
| err = junk(&nladdr, h, arg2); |
| if (err < 0) |
| return err; |
| } |
| goto skip_it; |
| } |
| |
| if (h->nlmsg_type == NLMSG_DONE) |
| return 0; |
| if (h->nlmsg_type == NLMSG_ERROR) { |
| struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); |
| if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) { |
| fprintf(stderr, "ERROR truncated\n"); |
| } else { |
| errno = -err->error; |
| perror("RTNETLINK answers"); |
| } |
| return -1; |
| } |
| err = filter(&nladdr, h, arg1); |
| if (err < 0) |
| return err; |
| |
| skip_it: |
| h = NLMSG_NEXT(h, status); |
| } |
| if (msg.msg_flags & MSG_TRUNC) { |
| fprintf(stderr, "Message truncated\n"); |
| continue; |
| } |
| if (status) { |
| fprintf(stderr, "!!!Remnant of size %d\n", status); |
| exit(1); |
| } |
| } |
| } |
| |
| int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer, |
| unsigned groups, struct nlmsghdr *answer, |
| rtnl_filter_t junk, |
| void *jarg) |
| { |
| int status; |
| unsigned seq; |
| struct nlmsghdr *h; |
| struct sockaddr_nl nladdr; |
| struct iovec iov = { |
| .iov_base = (void*) n, |
| .iov_len = n->nlmsg_len |
| }; |
| struct msghdr msg = { |
| .msg_name = &nladdr, |
| .msg_namelen = sizeof(nladdr), |
| .msg_iov = &iov, |
| .msg_iovlen = 1, |
| }; |
| char buf[16384]; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| nladdr.nl_pid = peer; |
| nladdr.nl_groups = groups; |
| |
| n->nlmsg_seq = seq = ++rtnl->seq; |
| |
| if (answer == NULL) |
| n->nlmsg_flags |= NLM_F_ACK; |
| |
| status = sendmsg(rtnl->fd, &msg, 0); |
| |
| if (status < 0) { |
| perror("Cannot talk to rtnetlink"); |
| return -1; |
| } |
| |
| memset(buf,0,sizeof(buf)); |
| |
| iov.iov_base = buf; |
| |
| while (1) { |
| iov.iov_len = sizeof(buf); |
| status = recvmsg(rtnl->fd, &msg, 0); |
| |
| if (status < 0) { |
| if (errno == EINTR || errno == EAGAIN) |
| continue; |
| fprintf(stderr, "netlink receive error %s (%d)\n", |
| strerror(errno), errno); |
| return -1; |
| } |
| if (status == 0) { |
| fprintf(stderr, "EOF on netlink\n"); |
| return -1; |
| } |
| if (msg.msg_namelen != sizeof(nladdr)) { |
| fprintf(stderr, "sender address length == %d\n", msg.msg_namelen); |
| exit(1); |
| } |
| for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) { |
| int err; |
| int len = h->nlmsg_len; |
| int l = len - sizeof(*h); |
| |
| if (l<0 || len>status) { |
| if (msg.msg_flags & MSG_TRUNC) { |
| fprintf(stderr, "Truncated message\n"); |
| return -1; |
| } |
| fprintf(stderr, "!!!malformed message: len=%d\n", len); |
| exit(1); |
| } |
| |
| if (nladdr.nl_pid != peer || |
| h->nlmsg_pid != rtnl->local.nl_pid || |
| h->nlmsg_seq != seq) { |
| if (junk) { |
| err = junk(&nladdr, h, jarg); |
| if (err < 0) |
| return err; |
| } |
| /* Don't forget to skip that message. */ |
| status -= NLMSG_ALIGN(len); |
| h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); |
| continue; |
| } |
| |
| if (h->nlmsg_type == NLMSG_ERROR) { |
| struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); |
| if (l < sizeof(struct nlmsgerr)) { |
| fprintf(stderr, "ERROR truncated\n"); |
| } else { |
| errno = -err->error; |
| if (errno == 0) { |
| if (answer) |
| memcpy(answer, h, h->nlmsg_len); |
| return 0; |
| } |
| perror("RTNETLINK answers"); |
| } |
| return -1; |
| } |
| if (answer) { |
| memcpy(answer, h, h->nlmsg_len); |
| return 0; |
| } |
| |
| fprintf(stderr, "Unexpected reply!!!\n"); |
| |
| status -= NLMSG_ALIGN(len); |
| h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); |
| } |
| if (msg.msg_flags & MSG_TRUNC) { |
| fprintf(stderr, "Message truncated\n"); |
| continue; |
| } |
| if (status) { |
| fprintf(stderr, "!!!Remnant of size %d\n", status); |
| exit(1); |
| } |
| } |
| } |
| |
| int rtnl_listen(struct rtnl_handle *rtnl, |
| rtnl_filter_t handler, |
| void *jarg) |
| { |
| int status; |
| struct nlmsghdr *h; |
| struct sockaddr_nl nladdr; |
| struct iovec iov; |
| struct msghdr msg = { |
| .msg_name = &nladdr, |
| .msg_namelen = sizeof(nladdr), |
| .msg_iov = &iov, |
| .msg_iovlen = 1, |
| }; |
| char buf[8192]; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| nladdr.nl_pid = 0; |
| nladdr.nl_groups = 0; |
| |
| iov.iov_base = buf; |
| while (1) { |
| iov.iov_len = sizeof(buf); |
| status = recvmsg(rtnl->fd, &msg, 0); |
| |
| if (status < 0) { |
| if (errno == EINTR || errno == EAGAIN) |
| continue; |
| fprintf(stderr, "netlink receive error %s (%d)\n", |
| strerror(errno), errno); |
| return -1; |
| } |
| if (status == 0) { |
| fprintf(stderr, "EOF on netlink\n"); |
| return -1; |
| } |
| if (msg.msg_namelen != sizeof(nladdr)) { |
| fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen); |
| exit(1); |
| } |
| for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) { |
| int err; |
| int len = h->nlmsg_len; |
| int l = len - sizeof(*h); |
| |
| if (l<0 || len>status) { |
| if (msg.msg_flags & MSG_TRUNC) { |
| fprintf(stderr, "Truncated message\n"); |
| return -1; |
| } |
| fprintf(stderr, "!!!malformed message: len=%d\n", len); |
| exit(1); |
| } |
| |
| err = handler(&nladdr, h, jarg); |
| if (err < 0) |
| return err; |
| |
| status -= NLMSG_ALIGN(len); |
| h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); |
| } |
| if (msg.msg_flags & MSG_TRUNC) { |
| fprintf(stderr, "Message truncated\n"); |
| continue; |
| } |
| if (status) { |
| fprintf(stderr, "!!!Remnant of size %d\n", status); |
| exit(1); |
| } |
| } |
| } |
| |
| int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler, |
| void *jarg) |
| { |
| int status; |
| struct sockaddr_nl nladdr; |
| char buf[8192]; |
| struct nlmsghdr *h = (void*)buf; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| nladdr.nl_pid = 0; |
| nladdr.nl_groups = 0; |
| |
| while (1) { |
| int err, len, type; |
| int l; |
| |
| status = fread(&buf, 1, sizeof(*h), rtnl); |
| |
| if (status < 0) { |
| if (errno == EINTR) |
| continue; |
| perror("rtnl_from_file: fread"); |
| return -1; |
| } |
| if (status == 0) |
| return 0; |
| |
| len = h->nlmsg_len; |
| type= h->nlmsg_type; |
| l = len - sizeof(*h); |
| |
| if (l<0 || len>sizeof(buf)) { |
| fprintf(stderr, "!!!malformed message: len=%d @%lu\n", |
| len, ftell(rtnl)); |
| return -1; |
| } |
| |
| status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl); |
| |
| if (status < 0) { |
| perror("rtnl_from_file: fread"); |
| return -1; |
| } |
| if (status < l) { |
| fprintf(stderr, "rtnl-from_file: truncated message\n"); |
| return -1; |
| } |
| |
| err = handler(&nladdr, h, jarg); |
| if (err < 0) |
| return err; |
| } |
| } |
| |
| int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data) |
| { |
| int len = RTA_LENGTH(4); |
| struct rtattr *rta; |
| if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) { |
| fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen); |
| return -1; |
| } |
| rta = NLMSG_TAIL(n); |
| rta->rta_type = type; |
| rta->rta_len = len; |
| memcpy(RTA_DATA(rta), &data, 4); |
| n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len; |
| return 0; |
| } |
| |
| int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data, |
| int alen) |
| { |
| int len = RTA_LENGTH(alen); |
| struct rtattr *rta; |
| |
| if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) { |
| fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen); |
| return -1; |
| } |
| rta = NLMSG_TAIL(n); |
| rta->rta_type = type; |
| rta->rta_len = len; |
| memcpy(RTA_DATA(rta), data, alen); |
| n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len); |
| return 0; |
| } |
| |
| int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len) |
| { |
| if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) { |
| fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen); |
| return -1; |
| } |
| |
| memcpy(NLMSG_TAIL(n), data, len); |
| memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len); |
| n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len); |
| return 0; |
| } |
| |
| struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type) |
| { |
| struct rtattr *nest = NLMSG_TAIL(n); |
| |
| addattr_l(n, maxlen, type, NULL, 0); |
| return nest; |
| } |
| |
| int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest) |
| { |
| nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest; |
| return n->nlmsg_len; |
| } |
| |
| struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type, |
| const void *data, int len) |
| { |
| struct rtattr *start = NLMSG_TAIL(n); |
| |
| addattr_l(n, maxlen, type, data, len); |
| addattr_nest(n, maxlen, type); |
| return start; |
| } |
| |
| int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start) |
| { |
| struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len); |
| |
| start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start; |
| addattr_nest_end(n, nest); |
| return n->nlmsg_len; |
| } |
| |
| int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data) |
| { |
| int len = RTA_LENGTH(4); |
| struct rtattr *subrta; |
| |
| if (RTA_ALIGN(rta->rta_len) + len > maxlen) { |
| fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen); |
| return -1; |
| } |
| subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); |
| subrta->rta_type = type; |
| subrta->rta_len = len; |
| memcpy(RTA_DATA(subrta), &data, 4); |
| rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len; |
| return 0; |
| } |
| |
| int rta_addattr_l(struct rtattr *rta, int maxlen, int type, |
| const void *data, int alen) |
| { |
| struct rtattr *subrta; |
| int len = RTA_LENGTH(alen); |
| |
| if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) { |
| fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen); |
| return -1; |
| } |
| subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); |
| subrta->rta_type = type; |
| subrta->rta_len = len; |
| memcpy(RTA_DATA(subrta), data, alen); |
| rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len); |
| return 0; |
| } |
| |
| int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len) |
| { |
| memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); |
| while (RTA_OK(rta, len)) { |
| if (rta->rta_type <= max) |
| tb[rta->rta_type] = rta; |
| rta = RTA_NEXT(rta,len); |
| } |
| if (len) |
| fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len); |
| return 0; |
| } |
| |
| int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len) |
| { |
| int i = 0; |
| |
| memset(tb, 0, sizeof(struct rtattr *) * max); |
| while (RTA_OK(rta, len)) { |
| if (rta->rta_type <= max && i < max) |
| tb[i++] = rta; |
| rta = RTA_NEXT(rta,len); |
| } |
| if (len) |
| fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len); |
| return i; |
| } |
| |
| int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta, |
| int len) |
| { |
| if (RTA_PAYLOAD(rta) < len) |
| return -1; |
| if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) { |
| rta = RTA_DATA(rta) + RTA_ALIGN(len); |
| return parse_rtattr_nested(tb, max, rta); |
| } |
| memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); |
| return 0; |
| } |