/*
* Copyright (c) 1998-2001
* University of Southern California/Information Sciences Institute.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Part of this program has been derived from mrouted.
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE.mrouted".
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*
*/
#include <sys/param.h>
#include <sys/file.h>
#include "defs.h"
#include <sys/socket.h>
#include <net/route.h>
#ifdef HAVE_ROUTING_SOCKETS
#include <net/if_dl.h>
#endif
#include <arpa/inet.h>
#include <netdb.h>
#include <stdlib.h>
/* All the BSDs have routing sockets (not Netlink), but only Linux seems
* to have SIOCGETRPF, which is used in the #else below ... the original
* authors wanted to merge routesock.c and netlink.c, but I don't know
* anymore. --Joachim */
#ifdef HAVE_ROUTING_SOCKETS
union sockunion {
struct sockaddr sa;
struct sockaddr_in sin;
struct sockaddr_dl sdl;
} so_dst, so_ifp;
typedef union sockunion *sup;
int routing_socket = -1;
int rtm_addrs;
static pid_t pid;
struct rt_metrics rt_metrics;
uint32_t rtm_inits;
struct {
struct rt_msghdr m_rtm;
char m_space[512];
} m_rtmsg;
/*
* Local functions definitions.
*/
static int getmsg(struct rt_msghdr *, int, struct rpfctl *rpfinfo);
/*
* TODO: check again!
*/
#ifdef IRIX
#define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) \
: sizeof(__uint64_t))
#else
#define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
: sizeof(long))
#endif /* IRIX */
#ifdef HAVE_SA_LEN
#define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
#else
#define ADVANCE(x, n) (x += ROUNDUP(sizeof(*(n)))) /* XXX: sizeof(struct sockaddr) */
#endif
/* Open and initialize the routing socket */
int init_routesock(void)
{
#if 0
int on = 0;
#endif
routing_socket = socket(PF_ROUTE, SOCK_RAW, 0);
if (routing_socket < 0) {
logit(LOG_ERR, errno, "Failed creating routing socket");
return -1;
}
if (fcntl(routing_socket, F_SETFL, O_NONBLOCK) == -1) {
logit(LOG_ERR, errno, "Failed setting routing socket as non-blocking");
return -1;
}
#if 0
/* XXX: if it is OFF, no queries will succeed (!?) */
if (setsockopt(routing_socket, SOL_SOCKET, SO_USELOOPBACK, (char *)&on, sizeof(on)) < 0) {
logit(LOG_ERR, errno , "setsockopt(SO_USELOOPBACK, 0)");
return -1;
}
#endif
return 0;
}
/* get the rpf neighbor info */
int k_req_incoming(uint32_t source, struct rpfctl *rpfp)
{
int rlen, l, flags = RTF_STATIC, retry_count = 3;
sup su;
static int seq;
char *cp = m_rtmsg.m_space;
struct rpfctl rpfinfo;
/* TODO: a hack!!!! */
#ifdef HAVE_SA_LEN
#define NEXTADDR(w, u) \
if (rtm_addrs & (w)) { \
l = ROUNDUP(u.sa.sa_len); \
memcpy(cp, &(u), l); \
cp += l; \
}
#else
#define NEXTADDR(w, u) \
if (rtm_addrs & (w)) { \
l = ROUNDUP(sizeof(struct sockaddr)); \
memcpy(cp, &(u), l); \
cp += l; \
}
#endif /* HAVE_SA_LEN */
/* initialize */
rpfp->rpfneighbor.s_addr = INADDR_ANY_N;
rpfp->source.s_addr = source;
/* check if local address or directly connected before calling the
* routing socket
*/
if ((rpfp->iif = find_vif_direct_local(source)) != NO_VIF) {
rpfp->rpfneighbor.s_addr = source;
return TRUE;
}
/* prepare the routing socket params */
rtm_addrs |= RTA_DST;
rtm_addrs |= RTA_IFP;
su = &so_dst;
su->sin.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
su->sin.sin_len = sizeof(struct sockaddr_in);
#endif
su->sin.sin_addr.s_addr = source;
if (inet_lnaof(su->sin.sin_addr) == INADDR_ANY) {
IF_DEBUG(DEBUG_RPF) {
logit(LOG_DEBUG, 0, "k_req_incoming: Invalid source %s",
inet_fmt(source, s1, sizeof(s1)));
}
return FALSE;
}
so_ifp.sa.sa_family = AF_LINK;
#ifdef HAVE_SA_LEN
so_ifp.sa.sa_len = sizeof(struct sockaddr_dl);
#endif
flags |= RTF_UP;
flags |= RTF_HOST;
flags |= RTF_GATEWAY;
errno = 0;
memset (&m_rtmsg, 0, sizeof(m_rtmsg));
#define rtm m_rtmsg.m_rtm
rtm.rtm_type = RTM_GET;
rtm.rtm_flags = flags;
rtm.rtm_version = RTM_VERSION;
rtm.rtm_seq = ++seq;
rtm.rtm_addrs = rtm_addrs;
rtm.rtm_rmx = rt_metrics;
rtm.rtm_inits = rtm_inits;
NEXTADDR(RTA_DST, so_dst);
NEXTADDR(RTA_IFP, so_ifp);
rtm.rtm_msglen = l = cp - (char *)&m_rtmsg;
rlen = write(routing_socket, &m_rtmsg, l);
if (rlen <= 0) {
IF_DEBUG(DEBUG_RPF | DEBUG_KERN) {
if (errno == ESRCH)
logit(LOG_DEBUG, 0, "Writing to routing socket: no such route");
else
logit(LOG_DEBUG, 0, "Error writing to routing socket");
}
return FALSE;
}
pid = getpid();
while (1) {
rlen = read(routing_socket, &m_rtmsg, sizeof(m_rtmsg));
if (rlen < 0) {
if (errno == EINTR)
continue; /* Signalled, retry syscall. */
if (errno == EAGAIN && retry_count--) {
logit(LOG_DEBUG, 0, "Kernel busy, retrying (%d/3) routing socket read in one sec ...", 3 - retry_count);
sleep(1);
continue;
}
IF_DEBUG(DEBUG_RPF | DEBUG_KERN)
logit(LOG_DEBUG, errno, "Read from routing socket failed");
return FALSE;
}
if (rlen > 0 && (rtm.rtm_seq != seq || rtm.rtm_pid != pid))
continue;
break;
}
memset(&rpfinfo, 0, sizeof(rpfinfo));
if (getmsg(&rtm, l, &rpfinfo)) {
rpfp->rpfneighbor.s_addr = rpfinfo.rpfneighbor.s_addr;
rpfp->iif = rpfinfo.iif;
}
#undef rtm
return TRUE;
}
static void find_sockaddrs(struct rt_msghdr *rtm, struct sockaddr **dst, struct sockaddr **gate,
struct sockaddr **mask, struct sockaddr_dl **ifp)
{
int i;
char *cp = (char *)(rtm + 1);
struct sockaddr *sa;
if (rtm->rtm_addrs) {
for (i = 1; i; i <<= 1) {
if (i & rtm->rtm_addrs) {
sa = (struct sockaddr *)cp;
switch (i) {
case RTA_DST:
*dst = sa;
break;
case RTA_GATEWAY:
*gate = sa;
break;
case RTA_NETMASK:
*mask = sa;
break;
case RTA_IFP:
if (sa->sa_family == AF_LINK && ((struct sockaddr_dl *)sa)->sdl_nlen)
*ifp = (struct sockaddr_dl *)sa;
break;
}
ADVANCE(cp, sa);
}
}
}
}
/*
* Returns TRUE on success, FALSE otherwise. rpfinfo contains the result.
*/
static int getmsg(struct rt_msghdr *rtm, int msglen __attribute__((unused)), struct rpfctl *rpf)
{
struct sockaddr *dst = NULL, *gate = NULL, *mask = NULL;
struct sockaddr_dl *ifp = NULL;
struct in_addr in;
vifi_t vifi;
struct uvif *v;
if (!rpf) {
logit(LOG_WARNING, 0, "Missing rpf pointer to routesock.c:getmsg()!");
return FALSE;
}
rpf->iif = NO_VIF;
rpf->rpfneighbor.s_addr = INADDR_ANY;
in = ((struct sockaddr_in *)&so_dst)->sin_addr;
IF_DEBUG(DEBUG_RPF)
logit(LOG_DEBUG, 0, "route to: %s", inet_fmt(in.s_addr, s1, sizeof(s1)));
find_sockaddrs(rtm, &dst, &gate, &mask, &ifp);
if (!ifp) { /* No incoming interface */
IF_DEBUG(DEBUG_RPF)
logit(LOG_DEBUG, 0, "No incoming interface for destination %s", inet_fmt(in.s_addr, s1, sizeof(s1)));
return FALSE;
}
if (dst && mask)
mask->sa_family = dst->sa_family;
if (dst) {
in = ((struct sockaddr_in *)dst)->sin_addr;
IF_DEBUG(DEBUG_RPF)
logit(LOG_DEBUG, 0, " destination is: %s", inet_fmt(in.s_addr, s1, sizeof(s1)));
}
if (gate && (rtm->rtm_flags & RTF_GATEWAY)) {
in = ((struct sockaddr_in *)gate)->sin_addr;
IF_DEBUG(DEBUG_RPF)
logit(LOG_DEBUG, 0, " gateway is: %s", inet_fmt(in.s_addr, s1, sizeof(s1)));
rpf->rpfneighbor = in;
}
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
/* get the number of the interface by matching the name */
if ((strlen(v->uv_name) == ifp->sdl_nlen)
&& !(strncmp(v->uv_name, ifp->sdl_data, ifp->sdl_nlen)))
break;
}
/* Found inbound interface in vifi */
rpf->iif = vifi;
IF_DEBUG(DEBUG_RPF)
logit(LOG_DEBUG, 0, " iif is %d", vifi);
if (vifi >= numvifs) {
IF_DEBUG(DEBUG_RPF)
logit(LOG_DEBUG, 0, "Invalid incoming interface for destination %s, because of invalid virtual interface",
inet_fmt(in.s_addr, s1, sizeof(s1)));
return FALSE; /* invalid iif */
}
return TRUE;
}
#else /* !HAVE_ROUTING_SOCKETS -- if we want to run on Linux without Netlink */
/* API compat dummy. */
int init_routesock(void)
{
return dup(udp_socket);
}
/*
* Return in rpfcinfo the incoming interface and the next hop router
* toward source.
*/
/* TODO: check whether next hop router address is in network or host order */
int k_req_incoming(uint32_t source, struct rpfctl *rpfcinfo)
{
rpfcinfo->source.s_addr = source;
rpfcinfo->iif = NO_VIF; /* Initialize, will be changed in kernel */
rpfcinfo->rpfneighbor.s_addr = INADDR_ANY; /* Initialize */
if (ioctl(udp_socket, SIOCGETRPF, (char *) rpfcinfo) < 0) {
logit(LOG_WARNING, errno, "Failed ioctl SIOCGETRPF in k_req_incoming()");
return FALSE;
}
return TRUE;
}
#endif /* HAVE_ROUTING_SOCKETS */
/**
* Local Variables:
* version-control: t
* indent-tabs-mode: t
* c-file-style: "ellemtel"
* c-basic-offset: 4
* End:
*/
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