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/*
* Copyright (c) 2012 Ed Maste. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "route-table.h"
#include <sys/socket.h>
#include <sys/types.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <errno.h>
#include <poll.h>
#include <string.h>
#include <unistd.h>
#include "ovs-router.h"
#include "packets.h"
#include "openvswitch/vlog.h"
#include "util.h"
VLOG_DEFINE_THIS_MODULE(route_table_bsd);
bool
route_table_fallback_lookup(ovs_be32 ip, char name[], ovs_be32 *gw)
{
struct {
struct rt_msghdr rtm;
char space[512];
} rtmsg;
struct rt_msghdr *rtm = &rtmsg.rtm;
struct sockaddr_dl *ifp = NULL;
struct sockaddr_in *sin;
struct sockaddr *sa;
static int seq;
int i, namelen, rtsock;
ssize_t len;
const pid_t pid = getpid();
bool got_ifp = false;
unsigned int retry_count = 5; /* arbitrary */
VLOG_DBG("looking route up for " IP_FMT " pid %" PRIuMAX,
IP_ARGS(ip), (uintmax_t)pid);
rtsock = socket(PF_ROUTE, SOCK_RAW, 0);
if (rtsock < 0)
return false;
retry:
memset(&rtmsg, 0, sizeof(rtmsg));
rtm->rtm_msglen = sizeof(struct rt_msghdr) + sizeof(struct sockaddr_in);
rtm->rtm_version = RTM_VERSION;
rtm->rtm_type = RTM_GET;
rtm->rtm_addrs = RTA_DST | RTA_IFP;
rtm->rtm_seq = ++seq;
sin = (struct sockaddr_in *)(rtm + 1);
sin->sin_len = len = sizeof(struct sockaddr_in);
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = ip;
len = write(rtsock, (char *)&rtmsg, rtm->rtm_msglen);
if (len == -1) {
if (errno == ENOBUFS && retry_count-- > 0) {
VLOG_INFO("Recoverable error writing to routing socket: %s",
ovs_strerror(errno));
usleep(500 * 1000); /* arbitrary */
goto retry;
}
VLOG_ERR("Error writing to routing socket: %s", ovs_strerror(errno));
close(rtsock);
return false;
}
if (len != rtm->rtm_msglen) {
VLOG_ERR("Short write to routing socket");
close(rtsock);
return false;
}
do {
struct pollfd pfd;
int ret;
memset(&pfd, 0, sizeof(pfd));
pfd.fd = rtsock;
pfd.events = POLLIN;
/*
* The timeout value below is somehow arbitrary.
* It's to detect the lost of routing messages due to
* buffer exhaustion etc. The routing socket is not
* reliable.
*/
ret = poll(&pfd, 1, 500);
if (ret == -1) {
VLOG_ERR("Error polling on routing socket: %s",
ovs_strerror(errno));
close(rtsock);
return false;
}
if (ret == 0) {
if (retry_count-- > 0) {
VLOG_INFO("Timeout; resending routing message");
goto retry;
}
close(rtsock);
return false;
}
len = read(rtsock, (char *)&rtmsg, sizeof(rtmsg));
if (len > 0) {
VLOG_DBG("got rtmsg pid %" PRIuMAX " seq %d",
(uintmax_t)rtmsg.rtm.rtm_pid,
rtmsg.rtm.rtm_seq);
}
} while (len > 0 && (rtmsg.rtm.rtm_seq != seq ||
rtmsg.rtm.rtm_pid != pid));
close(rtsock);
if (len == -1) {
VLOG_ERR("Error reading from routing socket: %s", ovs_strerror(errno));
return false;
}
*gw = 0;
sa = (struct sockaddr *)(rtm + 1);
for (i = 1; i; i <<= 1) {
if (rtm->rtm_addrs & i) {
if (i == RTA_IFP && sa->sa_family == AF_LINK &&
ALIGNED_CAST(struct sockaddr_dl *, sa)->sdl_nlen) {
ifp = ALIGNED_CAST(struct sockaddr_dl *, sa);
namelen = ifp->sdl_nlen;
if (namelen > IFNAMSIZ - 1)
namelen = IFNAMSIZ - 1;
memcpy(name, ifp->sdl_data, namelen);
name[namelen] = '\0';
VLOG_DBG("got ifp %s", name);
got_ifp = true;
} else if (i == RTA_GATEWAY && sa->sa_family == AF_INET) {
const struct sockaddr_in *sin_dst =
ALIGNED_CAST(struct sockaddr_in *, sa);
*gw = sin_dst->sin_addr.s_addr;
VLOG_DBG("got gateway " IP_FMT, IP_ARGS(*gw));
}
#if defined(__FreeBSD__)
sa = (struct sockaddr *)((char *)sa + SA_SIZE(sa));
#elif defined(__NetBSD__)
sa = (struct sockaddr *)((char *)sa + RT_ROUNDUP(sa->sa_len));
#else
#error unimplemented
#endif
}
}
return got_ifp;
}
uint64_t
route_table_get_change_seq(void)
{
return 0;
}
void
route_table_init(void)
{
ovs_router_init();
}
void
route_table_run(void)
{
}
void
route_table_wait(void)
{
}
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