struct ifaddr *
ifa_ifwithroute(int flags, struct sockaddr *dst, struct sockaddr *gateway,
u_int rtableid)
{
struct ifaddr *ifa;
#ifdef IPSEC
/*
* If the destination is a PF_KEY address, we'll look
* for the existence of a encap interface number or address
* in the options list of the gateway. By default, we'll return
* enc0.
*/
if (dst && (dst->sa_family == PF_KEY))
return (encap_findgwifa(gateway));
#endif
if ((flags & RTF_GATEWAY) == 0) {
/*
* If we are adding a route to an interface,
* and the interface is a pt to pt link
* we should search for the destination
* as our clue to the interface. Otherwise
* we can use the local address.
*/
ifa = NULL;
if (flags & RTF_HOST)
ifa = ifa_ifwithdstaddr(dst, rtableid);
if (ifa == NULL)
ifa = ifa_ifwithaddr(gateway, rtableid);
} else {
/*
* If we are adding a route to a remote net
* or host, the gateway may still be on the
* other end of a pt to pt link.
*/
ifa = ifa_ifwithdstaddr(gateway, rtableid);
}
if (ifa == NULL)
ifa = ifa_ifwithnet(gateway, rtableid);
if (ifa == NULL) {
struct rtentry *rt = rtalloc1(gateway, 0, rtable_l2(rtableid));
if (rt == NULL)
return (NULL);
rt->rt_refcnt--;
/* The gateway must be local if the same address family. */
if ((rt->rt_flags & RTF_GATEWAY) &&
rt_key(rt)->sa_family == dst->sa_family)
return (0);
if ((ifa = rt->rt_ifa) == NULL)
return (NULL);
}
if (ifa->ifa_addr->sa_family != dst->sa_family) {
struct ifaddr *oifa = ifa;
ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
if (ifa == NULL)
ifa = oifa;
}
return (ifa);
}
int
rt_getifa(struct rt_addrinfo *info, u_int rtid)
{
struct ifaddr *ifa;
int error = 0;
/*
* ifp may be specified by sockaddr_dl when protocol address
* is ambiguous
*/
if (info->rti_ifp == NULL && info->rti_info[RTAX_IFP] != NULL
&& info->rti_info[RTAX_IFP]->sa_family == AF_LINK &&
(ifa = ifa_ifwithnet((struct sockaddr *)info->rti_info[RTAX_IFP],
rtid)) != NULL)
info->rti_ifp = ifa->ifa_ifp;
if (info->rti_ifa == NULL && info->rti_info[RTAX_IFA] != NULL)
info->rti_ifa = ifa_ifwithaddr(info->rti_info[RTAX_IFA], rtid);
if (info->rti_ifa == NULL) {
struct sockaddr *sa;
if ((sa = info->rti_info[RTAX_IFA]) == NULL)
if ((sa = info->rti_info[RTAX_GATEWAY]) == NULL)
sa = info->rti_info[RTAX_DST];
if (sa != NULL && info->rti_ifp != NULL)
info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
else if (info->rti_info[RTAX_DST] != NULL &&
info->rti_info[RTAX_GATEWAY] != NULL)
info->rti_ifa = ifa_ifwithroute(info->rti_flags,
info->rti_info[RTAX_DST],
info->rti_info[RTAX_GATEWAY],
rtid);
else if (sa != NULL)
info->rti_ifa = ifa_ifwithroute(info->rti_flags,
sa, sa, rtid);
}
if ((ifa = info->rti_ifa) != NULL) {
if (info->rti_ifp == NULL)
info->rti_ifp = ifa->ifa_ifp;
} else
error = ENETUNREACH;
return (error);
}
/*
* Default action when installing a route with a Link Level gateway.
* Lookup an appropriate real ifa to point to.
* This should be moved to /sys/net/link.c eventually.
*/
static void
link_rtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa)
{
struct ifaddr *ifa;
struct sockaddr *dst;
struct ifnet *ifp;
if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == 0) ||
((ifp = ifa->ifa_ifp) == 0) || ((dst = rt_key(rt)) == 0))
return;
ifa = ifaof_ifpforaddr(dst, ifp);
if (ifa) {
IFAFREE(rt->rt_ifa);
rt->rt_ifa = ifa;
ifa->ifa_refcnt++;
if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
ifa->ifa_rtrequest(cmd, rt, sa);
}
}
/*
* Do option processing on a datagram, possibly discarding it if bad options
* are encountered, or forwarding it if source-routed.
*
* The pass argument is used when operating in the IPSTEALTH mode to tell
* what options to process: [LS]SRR (pass 0) or the others (pass 1). The
* reason for as many as two passes is that when doing IPSTEALTH, non-routing
* options should be processed only if the packet is for us.
*
* Returns 1 if packet has been forwarded/freed, 0 if the packet should be
* processed further.
*/
int
ip_dooptions(struct mbuf *m, int pass)
{
struct ip *ip = mtod(m, struct ip *);
u_char *cp;
struct in_ifaddr *ia;
int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
struct in_addr *sin, dst;
uint32_t ntime;
struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
/* Ignore or reject packets with IP options. */
if (ip_doopts == 0)
return 0;
else if (ip_doopts == 2) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_FILTER_PROHIB;
goto bad;
}
dst = ip->ip_dst;
cp = (u_char *)(ip + 1);
cnt = (ip->ip_hl << 2) - sizeof (struct ip);
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[IPOPT_OPTVAL];
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP)
optlen = 1;
else {
if (cnt < IPOPT_OLEN + sizeof(*cp)) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
optlen = cp[IPOPT_OLEN];
if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
}
switch (opt) {
default:
break;
/*
* Source routing with record. Find interface with current
* destination address. If none on this machine then drop if
* strictly routed, or do nothing if loosely routed. Record
* interface address and bring up next address component. If
* strictly routed make sure next address is on directly
* accessible net.
*/
case IPOPT_LSRR:
case IPOPT_SSRR:
#ifdef IPSTEALTH
if (V_ipstealth && pass > 0)
break;
#endif
if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
ipaddr.sin_addr = ip->ip_dst;
if (ifa_ifwithaddr_check((struct sockaddr *)&ipaddr)
== 0) {
if (opt == IPOPT_SSRR) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
if (!ip_dosourceroute)
goto nosourcerouting;
/*
* Loose routing, and not at next destination
* yet; nothing to do except forward.
*/
break;
}
off--; /* 0 origin */
if (off > optlen - (int)sizeof(struct in_addr)) {
/*
* End of source route. Should be for us.
*/
if (!ip_acceptsourceroute)
goto nosourcerouting;
save_rte(m, cp, ip->ip_src);
break;
}
#ifdef IPSTEALTH
if (V_ipstealth)
goto dropit;
#endif
if (!ip_dosourceroute) {
if (V_ipforwarding) {
char buf[16]; /* aaa.bbb.ccc.ddd\0 */
/*
* Acting as a router, so generate
* ICMP
*/
nosourcerouting:
strcpy(buf, inet_ntoa(ip->ip_dst));
log(LOG_WARNING,
"attempted source route from %s to %s\n",
inet_ntoa(ip->ip_src), buf);
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
} else {
/*
* Not acting as a router, so
* silently drop.
*/
#ifdef IPSTEALTH
dropit:
#endif
IPSTAT_INC(ips_cantforward);
m_freem(m);
return (1);
}
}
/*
* locate outgoing interface
*/
(void)memcpy(&ipaddr.sin_addr, cp + off,
sizeof(ipaddr.sin_addr));
if (opt == IPOPT_SSRR) {
#define INA struct in_ifaddr *
#define SA struct sockaddr *
if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == NULL)
ia = (INA)ifa_ifwithnet((SA)&ipaddr, 0);
} else
/* XXX MRT 0 for routing */
ia = ip_rtaddr(ipaddr.sin_addr, M_GETFIB(m));
if (ia == NULL) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
ip->ip_dst = ipaddr.sin_addr;
(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
sizeof(struct in_addr));
ifa_free(&ia->ia_ifa);
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
/*
* Let ip_intr's mcast routing check handle mcast pkts
*/
forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
break;
case IPOPT_RR:
#ifdef IPSTEALTH
if (V_ipstealth && pass == 0)
break;
#endif
if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
/*
* If no space remains, ignore.
*/
off--; /* 0 origin */
if (off > optlen - (int)sizeof(struct in_addr))
break;
(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
sizeof(ipaddr.sin_addr));
/*
* Locate outgoing interface; if we're the
* destination, use the incoming interface (should be
* same).
*/
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == NULL &&
(ia = ip_rtaddr(ipaddr.sin_addr, M_GETFIB(m))) == NULL) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
goto bad;
}
(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
sizeof(struct in_addr));
ifa_free(&ia->ia_ifa);
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
break;
case IPOPT_TS:
#ifdef IPSTEALTH
if (V_ipstealth && pass == 0)
break;
#endif
code = cp - (u_char *)ip;
if (optlen < 4 || optlen > 40) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
if ((off = cp[IPOPT_OFFSET]) < 5) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
if (off > optlen - (int)sizeof(int32_t)) {
cp[IPOPT_OFFSET + 1] += (1 << 4);
if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
break;
}
off--; /* 0 origin */
sin = (struct in_addr *)(cp + off);
switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
case IPOPT_TS_TSONLY:
break;
case IPOPT_TS_TSANDADDR:
if (off + sizeof(uint32_t) +
sizeof(struct in_addr) > optlen) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
ipaddr.sin_addr = dst;
ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
m->m_pkthdr.rcvif);
if (ia == NULL)
continue;
(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
sizeof(struct in_addr));
ifa_free(&ia->ia_ifa);
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
off += sizeof(struct in_addr);
break;
case IPOPT_TS_PRESPEC:
if (off + sizeof(uint32_t) +
sizeof(struct in_addr) > optlen) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
(void)memcpy(&ipaddr.sin_addr, sin,
sizeof(struct in_addr));
if (ifa_ifwithaddr_check((SA)&ipaddr) == 0)
continue;
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
off += sizeof(struct in_addr);
break;
default:
code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
goto bad;
}
ntime = iptime();
(void)memcpy(cp + off, &ntime, sizeof(uint32_t));
cp[IPOPT_OFFSET] += sizeof(uint32_t);
}
}
if (forward && V_ipforwarding) {
ip_forward(m, 1);
return (1);
}
return (0);
bad:
icmp_error(m, type, code, 0, 0);
IPSTAT_INC(ips_badoptions);
return (1);
}