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- /*
- * 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>
- *
- * --
- *
- * This code has been lightly modified to adapt it in the Netsukuku source
- * code.
- */
-
- #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 <stdarg.h>
-
- #include "libnetlink.h"
- #include "log.h"
-
- void
- rtnl_close(struct rtnl_handle *rth)
- {
- close(rth->fd);
- }
-
- 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(struct rtnl_handle));
-
- 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)) {
- error("Wrong address length %d\n", addr_len);
- return -1;
- }
- if (rth->local.nl_family != AF_NETLINK) {
- error("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)
- continue;
- perror("OVERRUN");
- continue;
- }
-
- if (status == 0) {
- error("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))) {
- error("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) {
- error("Message truncated\n");
- continue;
- }
- if (status) {
- fatal("!!!Remnant of size %d\n", status);
- }
- }
- }
-
- 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)
- continue;
- perror("OVERRUN");
- continue;
- }
- if (status == 0) {
- error("EOF on netlink\n");
- return -1;
- }
- if (msg.msg_namelen != sizeof(nladdr)) {
- fatal("sender address length == %d\n", msg.msg_namelen);
- }
- 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) {
- error("Truncated message\n");
- return -1;
- }
- fatal("!!!malformed message: len=%d\n", len);
- }
-
- 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;
- }
- continue;
- }
-
- if (h->nlmsg_type == NLMSG_ERROR) {
- struct nlmsgerr *err = (struct nlmsgerr *) NLMSG_DATA(h);
- if (l < sizeof(struct nlmsgerr)) {
- error("ERROR truncated\n");
- } else {
- errno = -err->error;
- if (errno == 0) {
- if (answer)
- memcpy(answer, h, h->nlmsg_len);
- return 0;
- }
- error("RTNETLINK answers (%d): %s", err->error,
- strerror(errno));
- }
- return -1;
- }
- if (answer) {
- memcpy(answer, h, h->nlmsg_len);
- return 0;
- }
-
- error("Unexpected reply!!!\n");
-
- status -= NLMSG_ALIGN(len);
- h = (struct nlmsghdr *) ((char *) h + NLMSG_ALIGN(len));
- }
- if (msg.msg_flags & MSG_TRUNC) {
- error("Message truncated\n");
- continue;
- }
- if (status)
- fatal("!!!Remnant of size %d\n", status);
- }
- }
-
- 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)
- continue;
- perror("OVERRUN");
- continue;
- }
- if (status == 0) {
- error("EOF on netlink\n");
- return -1;
- }
- if (msg.msg_namelen != sizeof(nladdr)) {
- fatal("Sender address length == %d\n", msg.msg_namelen);
- }
- 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) {
- error("Truncated message\n");
- return -1;
- }
- fatal("!!!malformed message: len=%d\n", len);
- }
-
- 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) {
- error("Message truncated\n");
- continue;
- }
- if (status) {
- fatal("!!!Remnant of size %d\n", status);
- }
- }
- }
-
- 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;
- 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;
- l = len - sizeof(*h);
-
- if (l < 0 || len > sizeof(buf)) {
- error("!!!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) {
- error("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, uint32_t data)
- {
- int len = RTA_LENGTH(4);
- struct rtattr *rta;
- if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
- error("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) {
- error("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) {
- error("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;
- }
-
- int
- rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t data)
- {
- int len = RTA_LENGTH(4);
- struct rtattr *subrta;
-
- if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
- error("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) + len > maxlen) {
- error("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) + 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)
- error("!!!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)
- error("!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
- return i;
- }
|