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/* $OpenBSD: ip_input.c,v 1.394 2024/05/08 13:01:30 bluhm Exp $ */
/* $NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $ */
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
*/
#include "pf.h"
#include "carp.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/mutex.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/pool.h>
#include <sys/task.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/netisr.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <net/if_types.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#endif
#if NPF > 0
#include <net/pfvar.h>
#endif
#ifdef MROUTING
#include <netinet/ip_mroute.h>
#endif
#ifdef IPSEC
#include <netinet/ip_ipsp.h>
#endif /* IPSEC */
#if NCARP > 0
#include <netinet/ip_carp.h>
#endif
/* values controllable via sysctl */
int ipforwarding = 0;
int ipmforwarding = 0;
int ipmultipath = 0;
int ipsendredirects = 1;
int ip_dosourceroute = 0;
int ip_defttl = IPDEFTTL;
int ip_mtudisc = 1;
int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
int ip_directedbcast = 0;
/* Protects `ipq' and `ip_frags'. */
struct mutex ipq_mutex = MUTEX_INITIALIZER(IPL_SOFTNET);
/* IP reassembly queue */
LIST_HEAD(, ipq) ipq;
/* Keep track of memory used for reassembly */
int ip_maxqueue = 300;
int ip_frags = 0;
const struct sysctl_bounded_args ipctl_vars[] = {
#ifdef MROUTING
{ IPCTL_MRTPROTO, &ip_mrtproto, SYSCTL_INT_READONLY },
#endif
{ IPCTL_FORWARDING, &ipforwarding, 0, 2 },
{ IPCTL_SENDREDIRECTS, &ipsendredirects, 0, 1 },
{ IPCTL_DEFTTL, &ip_defttl, 0, 255 },
{ IPCTL_DIRECTEDBCAST, &ip_directedbcast, 0, 1 },
{ IPCTL_IPPORT_FIRSTAUTO, &ipport_firstauto, 0, 65535 },
{ IPCTL_IPPORT_LASTAUTO, &ipport_lastauto, 0, 65535 },
{ IPCTL_IPPORT_HIFIRSTAUTO, &ipport_hifirstauto, 0, 65535 },
{ IPCTL_IPPORT_HILASTAUTO, &ipport_hilastauto, 0, 65535 },
{ IPCTL_IPPORT_MAXQUEUE, &ip_maxqueue, 0, 10000 },
{ IPCTL_MFORWARDING, &ipmforwarding, 0, 1 },
{ IPCTL_ARPTIMEOUT, &arpt_keep, 0, INT_MAX },
{ IPCTL_ARPDOWN, &arpt_down, 0, INT_MAX },
};
struct niqueue ipintrq = NIQUEUE_INITIALIZER(IPQ_MAXLEN, NETISR_IP);
struct pool ipqent_pool;
struct pool ipq_pool;
struct cpumem *ipcounters;
int ip_sysctl_ipstat(void *, size_t *, void *);
static struct mbuf_queue ipsend_mq;
static struct mbuf_queue ipsendraw_mq;
extern struct niqueue arpinq;
int ip_ours(struct mbuf **, int *, int, int);
int ip_dooptions(struct mbuf *, struct ifnet *);
int in_ouraddr(struct mbuf *, struct ifnet *, struct route *);
int ip_fragcheck(struct mbuf **, int *);
struct mbuf * ip_reass(struct ipqent *, struct ipq *);
void ip_freef(struct ipq *);
void ip_flush(void);
static void ip_send_dispatch(void *);
static void ip_sendraw_dispatch(void *);
static struct task ipsend_task = TASK_INITIALIZER(ip_send_dispatch, &ipsend_mq);
static struct task ipsendraw_task =
TASK_INITIALIZER(ip_sendraw_dispatch, &ipsendraw_mq);
/*
* Used to save the IP options in case a protocol wants to respond
* to an incoming packet over the same route if the packet got here
* using IP source routing. This allows connection establishment and
* maintenance when the remote end is on a network that is not known
* to us.
*/
struct ip_srcrt {
int isr_nhops; /* number of hops */
struct in_addr isr_dst; /* final destination */
char isr_nop; /* one NOP to align */
char isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */
struct in_addr isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)];
};
void save_rte(struct mbuf *, u_char *, struct in_addr);
/*
* IP initialization: fill in IP protocol switch table.
* All protocols not implemented in kernel go to raw IP protocol handler.
*/
void
ip_init(void)
{
const struct protosw *pr;
int i;
const u_int16_t defbaddynamicports_tcp[] = DEFBADDYNAMICPORTS_TCP;
const u_int16_t defbaddynamicports_udp[] = DEFBADDYNAMICPORTS_UDP;
const u_int16_t defrootonlyports_tcp[] = DEFROOTONLYPORTS_TCP;
const u_int16_t defrootonlyports_udp[] = DEFROOTONLYPORTS_UDP;
ipcounters = counters_alloc(ips_ncounters);
pool_init(&ipqent_pool, sizeof(struct ipqent), 0,
IPL_SOFTNET, 0, "ipqe", NULL);
pool_init(&ipq_pool, sizeof(struct ipq), 0,
IPL_SOFTNET, 0, "ipq", NULL);
pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
panic("ip_init");
for (i = 0; i < IPPROTO_MAX; i++)
ip_protox[i] = pr - inetsw;
for (pr = inetdomain.dom_protosw;
pr < inetdomain.dom_protoswNPROTOSW; pr++)
if (pr->pr_domain->dom_family == PF_INET &&
pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW &&
pr->pr_protocol < IPPROTO_MAX)
ip_protox[pr->pr_protocol] = pr - inetsw;
LIST_INIT(&ipq);
/* Fill in list of ports not to allocate dynamically. */
memset(&baddynamicports, 0, sizeof(baddynamicports));
for (i = 0; defbaddynamicports_tcp[i] != 0; i++)
DP_SET(baddynamicports.tcp, defbaddynamicports_tcp[i]);
for (i = 0; defbaddynamicports_udp[i] != 0; i++)
DP_SET(baddynamicports.udp, defbaddynamicports_udp[i]);
/* Fill in list of ports only root can bind to. */
memset(&rootonlyports, 0, sizeof(rootonlyports));
for (i = 0; defrootonlyports_tcp[i] != 0; i++)
DP_SET(rootonlyports.tcp, defrootonlyports_tcp[i]);
for (i = 0; defrootonlyports_udp[i] != 0; i++)
DP_SET(rootonlyports.udp, defrootonlyports_udp[i]);
mq_init(&ipsend_mq, 64, IPL_SOFTNET);
mq_init(&ipsendraw_mq, 64, IPL_SOFTNET);
arpinit();
#ifdef IPSEC
ipsec_init();
#endif
#ifdef MROUTING
rt_timer_queue_init(&ip_mrouterq, MCAST_EXPIRE_FREQUENCY,
&mfc_expire_route);
#endif
}
/*
* Enqueue packet for local delivery. Queuing is used as a boundary
* between the network layer (input/forward path) running with
* NET_LOCK_SHARED() and the transport layer needing it exclusively.
*/
int
ip_ours(struct mbuf **mp, int *offp, int nxt, int af)
{
nxt = ip_fragcheck(mp, offp);
if (nxt == IPPROTO_DONE)
return IPPROTO_DONE;
/* We are already in a IPv4/IPv6 local deliver loop. */
if (af != AF_UNSPEC)
return nxt;
nxt = ip_deliver(mp, offp, nxt, AF_INET, 1);
if (nxt == IPPROTO_DONE)
return IPPROTO_DONE;
/* save values for later, use after dequeue */
if (*offp != sizeof(struct ip)) {
struct m_tag *mtag;
struct ipoffnxt *ion;
/* mbuf tags are expensive, but only used for header options */
mtag = m_tag_get(PACKET_TAG_IP_OFFNXT, sizeof(*ion),
M_NOWAIT);
if (mtag == NULL) {
ipstat_inc(ips_idropped);
m_freemp(mp);
return IPPROTO_DONE;
}
ion = (struct ipoffnxt *)(mtag + 1);
ion->ion_off = *offp;
ion->ion_nxt = nxt;
m_tag_prepend(*mp, mtag);
}
niq_enqueue(&ipintrq, *mp);
*mp = NULL;
return IPPROTO_DONE;
}
/*
* Dequeue and process locally delivered packets.
* This is called with exclusive NET_LOCK().
*/
void
ipintr(void)
{
struct mbuf *m;
while ((m = niq_dequeue(&ipintrq)) != NULL) {
struct m_tag *mtag;
int off, nxt;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ipintr no HDR");
#endif
mtag = m_tag_find(m, PACKET_TAG_IP_OFFNXT, NULL);
if (mtag != NULL) {
struct ipoffnxt *ion;
ion = (struct ipoffnxt *)(mtag + 1);
off = ion->ion_off;
nxt = ion->ion_nxt;
m_tag_delete(m, mtag);
} else {
struct ip *ip;
ip = mtod(m, struct ip *);
off = ip->ip_hl << 2;
nxt = ip->ip_p;
}
nxt = ip_deliver(&m, &off, nxt, AF_INET, 0);
KASSERT(nxt == IPPROTO_DONE);
}
}
/*
* IPv4 input routine.
*
* Checksum and byte swap header. Process options. Forward or deliver.
*/
void
ipv4_input(struct ifnet *ifp, struct mbuf *m)
{
int off, nxt;
off = 0;
nxt = ip_input_if(&m, &off, IPPROTO_IPV4, AF_UNSPEC, ifp);
KASSERT(nxt == IPPROTO_DONE);
}
struct mbuf *
ipv4_check(struct ifnet *ifp, struct mbuf *m)
{
struct ip *ip;
int hlen, len;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (m == NULL) {
ipstat_inc(ips_toosmall);
return (NULL);
}
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
ipstat_inc(ips_badvers);
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen < sizeof(*ip)) { /* minimum header length */
ipstat_inc(ips_badhlen);
goto bad;
}
if (hlen > m->m_len) {
m = m_pullup(m, hlen);
if (m == NULL) {
ipstat_inc(ips_badhlen);
return (NULL);
}
ip = mtod(m, struct ip *);
}
/* 127/8 must not appear on wire - RFC1122 */
if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
(ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
ipstat_inc(ips_badaddr);
goto bad;
}
}
if (!ISSET(m->m_pkthdr.csum_flags, M_IPV4_CSUM_IN_OK)) {
if (ISSET(m->m_pkthdr.csum_flags, M_IPV4_CSUM_IN_BAD)) {
ipstat_inc(ips_badsum);
goto bad;
}
ipstat_inc(ips_inswcsum);
if (in_cksum(m, hlen) != 0) {
ipstat_inc(ips_badsum);
goto bad;
}
SET(m->m_pkthdr.csum_flags, M_IPV4_CSUM_IN_OK);
}
/* Retrieve the packet length. */
len = ntohs(ip->ip_len);
/*
* Convert fields to host representation.
*/
if (len < hlen) {
ipstat_inc(ips_badlen);
goto bad;
}
/*
* Check that the amount of data in the buffers
* is at least as much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len < len) {
ipstat_inc(ips_tooshort);
goto bad;
}
if (m->m_pkthdr.len > len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = len;
m->m_pkthdr.len = len;
} else
m_adj(m, len - m->m_pkthdr.len);
}
return (m);
bad:
m_freem(m);
return (NULL);
}
int
ip_input_if(struct mbuf **mp, int *offp, int nxt, int af, struct ifnet *ifp)
{
struct route ro;
struct mbuf *m;
struct ip *ip;
int hlen;
#if NPF > 0
struct in_addr odst;
#endif
int pfrdr = 0;
KASSERT(*offp == 0);
ro.ro_rt = NULL;
ipstat_inc(ips_total);
m = *mp = ipv4_check(ifp, *mp);
if (m == NULL)
goto bad;
ip = mtod(m, struct ip *);
#if NCARP > 0
if (carp_lsdrop(ifp, m, AF_INET, &ip->ip_src.s_addr,
&ip->ip_dst.s_addr, (ip->ip_p == IPPROTO_ICMP ? 0 : 1)))
goto bad;
#endif
#if NPF > 0
/*
* Packet filter
*/
odst = ip->ip_dst;
if (pf_test(AF_INET, PF_IN, ifp, mp) != PF_PASS)
goto bad;
m = *mp;
if (m == NULL)
goto bad;
ip = mtod(m, struct ip *);
pfrdr = odst.s_addr != ip->ip_dst.s_addr;
#endif
hlen = ip->ip_hl << 2;
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
if (hlen > sizeof (struct ip) && ip_dooptions(m, ifp)) {
m = *mp = NULL;
goto bad;
}
if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
ip->ip_dst.s_addr == INADDR_ANY) {
nxt = ip_ours(mp, offp, nxt, af);
goto out;
}
switch(in_ouraddr(m, ifp, &ro)) {
case 2:
goto bad;
case 1:
nxt = ip_ours(mp, offp, nxt, af);
goto out;
}
if (IN_MULTICAST(ip->ip_dst.s_addr)) {
/*
* Make sure M_MCAST is set. It should theoretically
* already be there, but let's play safe because upper
* layers check for this flag.
*/
m->m_flags |= M_MCAST;
#ifdef MROUTING
if (ipmforwarding && ip_mrouter[ifp->if_rdomain]) {
int error;
if (m->m_flags & M_EXT) {
if ((m = *mp = m_pullup(m, hlen)) == NULL) {
ipstat_inc(ips_toosmall);
goto bad;
}
ip = mtod(m, struct ip *);
}
/*
* If we are acting as a multicast router, all
* incoming multicast packets are passed to the
* kernel-level multicast forwarding function.
* The packet is returned (relatively) intact; if
* ip_mforward() returns a non-zero value, the packet
* must be discarded, else it may be accepted below.
*
* (The IP ident field is put in the same byte order
* as expected when ip_mforward() is called from
* ip_output().)
*/
KERNEL_LOCK();
error = ip_mforward(m, ifp);
KERNEL_UNLOCK();
if (error) {
ipstat_inc(ips_cantforward);
goto bad;
}
/*
* The process-level routing daemon needs to receive
* all multicast IGMP packets, whether or not this
* host belongs to their destination groups.
*/
if (ip->ip_p == IPPROTO_IGMP) {
nxt = ip_ours(mp, offp, nxt, af);
goto out;
}
ipstat_inc(ips_forward);
}
#endif
/*
* See if we belong to the destination multicast group on the
* arrival interface.
*/
if (!in_hasmulti(&ip->ip_dst, ifp)) {
ipstat_inc(ips_notmember);
if (!IN_LOCAL_GROUP(ip->ip_dst.s_addr))
ipstat_inc(ips_cantforward);
goto bad;
}
nxt = ip_ours(mp, offp, nxt, af);
goto out;
}
#if NCARP > 0
if (ip->ip_p == IPPROTO_ICMP &&
carp_lsdrop(ifp, m, AF_INET, &ip->ip_src.s_addr,
&ip->ip_dst.s_addr, 1))
goto bad;
#endif
/*
* Not for us; forward if possible and desirable.
*/
if (ipforwarding == 0) {
ipstat_inc(ips_cantforward);
goto bad;
}
#ifdef IPSEC
if (ipsec_in_use) {
int rv;
rv = ipsec_forward_check(m, hlen, AF_INET);
if (rv != 0) {
ipstat_inc(ips_cantforward);
goto bad;
}
/*
* Fall through, forward packet. Outbound IPsec policy
* checking will occur in ip_output().
*/
}
#endif /* IPSEC */
ip_forward(m, ifp, &ro, pfrdr);
*mp = NULL;
rtfree(ro.ro_rt);
return IPPROTO_DONE;
bad:
nxt = IPPROTO_DONE;
m_freemp(mp);
out:
rtfree(ro.ro_rt);
return nxt;
}
int
ip_fragcheck(struct mbuf **mp, int *offp)
{
struct ip *ip;
struct ipq *fp;
struct ipqent *ipqe;
int hlen;
uint16_t mff;
ip = mtod(*mp, struct ip *);
hlen = ip->ip_hl << 2;
/*
* If offset or more fragments are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*/
if (ISSET(ip->ip_off, htons(IP_OFFMASK | IP_MF))) {
if ((*mp)->m_flags & M_EXT) { /* XXX */
if ((*mp = m_pullup(*mp, hlen)) == NULL) {
ipstat_inc(ips_toosmall);
return IPPROTO_DONE;
}
ip = mtod(*mp, struct ip *);
}
/*
* Adjust ip_len to not reflect header,
* set ipqe_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
mff = ISSET(ip->ip_off, htons(IP_MF));
if (mff) {
/*
* Make sure that fragments have a data length
* that's a non-zero multiple of 8 bytes.
*/
if (ntohs(ip->ip_len) == 0 ||
(ntohs(ip->ip_len) & 0x7) != 0) {
ipstat_inc(ips_badfrags);
m_freemp(mp);
return IPPROTO_DONE;
}
}
ip->ip_off = htons(ntohs(ip->ip_off) << 3);
mtx_enter(&ipq_mutex);
/*
* Look for queue of fragments
* of this datagram.
*/
LIST_FOREACH(fp, &ipq, ipq_q) {
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
break;
}
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (mff || ip->ip_off) {
ipstat_inc(ips_fragments);
if (ip_frags + 1 > ip_maxqueue) {
ip_flush();
ipstat_inc(ips_rcvmemdrop);
goto bad;
}
ipqe = pool_get(&ipqent_pool, PR_NOWAIT);
if (ipqe == NULL) {
ipstat_inc(ips_rcvmemdrop);
goto bad;
}
ip_frags++;
ipqe->ipqe_mff = mff;
ipqe->ipqe_m = *mp;
ipqe->ipqe_ip = ip;
*mp = ip_reass(ipqe, fp);
if (*mp == NULL)
goto bad;
ipstat_inc(ips_reassembled);
ip = mtod(*mp, struct ip *);
hlen = ip->ip_hl << 2;
ip->ip_len = htons(ntohs(ip->ip_len) + hlen);
} else {
if (fp != NULL)
ip_freef(fp);
}
mtx_leave(&ipq_mutex);
}
*offp = hlen;
return ip->ip_p;
bad:
mtx_leave(&ipq_mutex);
m_freemp(mp);
return IPPROTO_DONE;
}
#ifndef INET6
#define IPSTAT_INC(name) ipstat_inc(ips_##name)
#else
#define IPSTAT_INC(name) (af == AF_INET ? \
ipstat_inc(ips_##name) : ip6stat_inc(ip6s_##name))
#endif
int
ip_deliver(struct mbuf **mp, int *offp, int nxt, int af, int shared)
{
#ifdef INET6
int nest = 0;
#endif
/*
* Tell launch routine the next header
*/
IPSTAT_INC(delivered);
while (nxt != IPPROTO_DONE) {
const struct protosw *psw;
int naf;
switch (af) {
case AF_INET:
psw = &inetsw[ip_protox[nxt]];
break;
#ifdef INET6
case AF_INET6:
psw = &inet6sw[ip6_protox[nxt]];
break;
#endif
}
if (shared && !ISSET(psw->pr_flags, PR_MPINPUT)) {
/* delivery not finished, decrement counter, queue */
switch (af) {
case AF_INET:
counters_dec(ipcounters, ips_delivered);
break;
#ifdef INET6
case AF_INET6:
counters_dec(ip6counters, ip6s_delivered);
break;
#endif
}
break;
}
#ifdef INET6
if (af == AF_INET6 &&
ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
ip6stat_inc(ip6s_toomanyhdr);
goto bad;
}
#endif
/*
* protection against faulty packet - there should be
* more sanity checks in header chain processing.
*/
if ((*mp)->m_pkthdr.len < *offp) {
IPSTAT_INC(tooshort);
goto bad;
}
#ifdef IPSEC
if (ipsec_in_use) {
if (ipsec_local_check(*mp, *offp, nxt, af) != 0) {
IPSTAT_INC(cantforward);
goto bad;
}
}
/* Otherwise, just fall through and deliver the packet */
#endif
switch (nxt) {
case IPPROTO_IPV4:
naf = AF_INET;
ipstat_inc(ips_delivered);
break;
#ifdef INET6
case IPPROTO_IPV6:
naf = AF_INET6;
ip6stat_inc(ip6s_delivered);
break;
#endif
default:
naf = af;
break;
}
nxt = (*psw->pr_input)(mp, offp, nxt, af);
af = naf;
}
return nxt;
bad:
m_freemp(mp);
return IPPROTO_DONE;
}
#undef IPSTAT_INC
int
in_ouraddr(struct mbuf *m, struct ifnet *ifp, struct route *ro)
{
struct rtentry *rt;
struct ip *ip;
int match = 0;
#if NPF > 0
switch (pf_ouraddr(m)) {
case 0:
return (0);
case 1:
return (1);
default:
/* pf does not know it */
break;
}
#endif
ip = mtod(m, struct ip *);
rt = route_mpath(ro, &ip->ip_dst, &ip->ip_src, m->m_pkthdr.ph_rtableid);
if (rt != NULL) {
if (ISSET(rt->rt_flags, RTF_LOCAL))
match = 1;
/*
* If directedbcast is enabled we only consider it local
* if it is received on the interface with that address.
*/
if (ISSET(rt->rt_flags, RTF_BROADCAST) &&
(!ip_directedbcast || rt->rt_ifidx == ifp->if_index)) {
match = 1;
/* Make sure M_BCAST is set */
m->m_flags |= M_BCAST;
}
}
if (!match) {
struct ifaddr *ifa;
/*
* No local address or broadcast address found, so check for
* ancient classful broadcast addresses.
* It must have been broadcast on the link layer, and for an
* address on the interface it was received on.
*/
if (!ISSET(m->m_flags, M_BCAST) ||
!IN_CLASSFULBROADCAST(ip->ip_dst.s_addr, ip->ip_dst.s_addr))
return (0);
if (ifp->if_rdomain != rtable_l2(m->m_pkthdr.ph_rtableid))
return (0);
/*
* The check in the loop assumes you only rx a packet on an UP
* interface, and that M_BCAST will only be set on a BROADCAST
* interface.
*/
NET_ASSERT_LOCKED();
TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
if (IN_CLASSFULBROADCAST(ip->ip_dst.s_addr,
ifatoia(ifa)->ia_addr.sin_addr.s_addr)) {
match = 1;
break;
}
}
} else if (ipforwarding == 0 && rt->rt_ifidx != ifp->if_index &&
!((ifp->if_flags & IFF_LOOPBACK) || (ifp->if_type == IFT_ENC) ||
(m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST))) {
/* received on wrong interface. */
#if NCARP > 0
struct ifnet *out_if;
/*
* Virtual IPs on carp interfaces need to be checked also
* against the parent interface and other carp interfaces
* sharing the same parent.
*/
out_if = if_get(rt->rt_ifidx);
if (!(out_if && carp_strict_addr_chk(out_if, ifp))) {
ipstat_inc(ips_wrongif);
match = 2;
}
if_put(out_if);
#else
ipstat_inc(ips_wrongif);
match = 2;
#endif
}
return (match);
}
/*
* Take incoming datagram fragment and try to
* reassemble it into whole datagram. If a chain for
* reassembly of this datagram already exists, then it
* is given as fp; otherwise have to make a chain.
*/
struct mbuf *
ip_reass(struct ipqent *ipqe, struct ipq *fp)
{
struct mbuf *m = ipqe->ipqe_m;
struct ipqent *nq, *p, *q;
struct ip *ip;
struct mbuf *t;
int hlen = ipqe->ipqe_ip->ip_hl << 2;
int i, next;
u_int8_t ecn, ecn0;
MUTEX_ASSERT_LOCKED(&ipq_mutex);
/*
* Presence of header sizes in mbufs
* would confuse code below.
*/
m->m_data += hlen;
m->m_len -= hlen;
/*
* If first fragment to arrive, create a reassembly queue.
*/
if (fp == NULL) {
fp = pool_get(&ipq_pool, PR_NOWAIT);
if (fp == NULL)
goto dropfrag;
LIST_INSERT_HEAD(&ipq, fp, ipq_q);
fp->ipq_ttl = IPFRAGTTL;
fp->ipq_p = ipqe->ipqe_ip->ip_p;
fp->ipq_id = ipqe->ipqe_ip->ip_id;
LIST_INIT(&fp->ipq_fragq);
fp->ipq_src = ipqe->ipqe_ip->ip_src;
fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
p = NULL;
goto insert;
}
/*
* Handle ECN by comparing this segment with the first one;
* if CE is set, do not lose CE.
* drop if CE and not-ECT are mixed for the same packet.
*/
ecn = ipqe->ipqe_ip->ip_tos & IPTOS_ECN_MASK;
ecn0 = LIST_FIRST(&fp->ipq_fragq)->ipqe_ip->ip_tos & IPTOS_ECN_MASK;
if (ecn == IPTOS_ECN_CE) {
if (ecn0 == IPTOS_ECN_NOTECT)
goto dropfrag;
if (ecn0 != IPTOS_ECN_CE)
LIST_FIRST(&fp->ipq_fragq)->ipqe_ip->ip_tos |=
IPTOS_ECN_CE;
}
if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
goto dropfrag;
/*
* Find a segment which begins after this one does.
*/
for (p = NULL, q = LIST_FIRST(&fp->ipq_fragq); q != NULL;
p = q, q = LIST_NEXT(q, ipqe_q))
if (ntohs(q->ipqe_ip->ip_off) > ntohs(ipqe->ipqe_ip->ip_off))
break;
/*
* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us.
*/
if (p != NULL) {
i = ntohs(p->ipqe_ip->ip_off) + ntohs(p->ipqe_ip->ip_len) -
ntohs(ipqe->ipqe_ip->ip_off);
if (i > 0) {
if (i >= ntohs(ipqe->ipqe_ip->ip_len))
goto dropfrag;
m_adj(ipqe->ipqe_m, i);
ipqe->ipqe_ip->ip_off =
htons(ntohs(ipqe->ipqe_ip->ip_off) + i);
ipqe->ipqe_ip->ip_len =
htons(ntohs(ipqe->ipqe_ip->ip_len) - i);
}
}
/*
* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.
*/
for (; q != NULL &&
ntohs(ipqe->ipqe_ip->ip_off) + ntohs(ipqe->ipqe_ip->ip_len) >
ntohs(q->ipqe_ip->ip_off); q = nq) {
i = (ntohs(ipqe->ipqe_ip->ip_off) +
ntohs(ipqe->ipqe_ip->ip_len)) - ntohs(q->ipqe_ip->ip_off);
if (i < ntohs(q->ipqe_ip->ip_len)) {
q->ipqe_ip->ip_len =
htons(ntohs(q->ipqe_ip->ip_len) - i);
q->ipqe_ip->ip_off =
htons(ntohs(q->ipqe_ip->ip_off) + i);
m_adj(q->ipqe_m, i);
break;
}
nq = LIST_NEXT(q, ipqe_q);
m_freem(q->ipqe_m);
LIST_REMOVE(q, ipqe_q);
pool_put(&ipqent_pool, q);
ip_frags--;
}
insert:
/*
* Stick new segment in its place;
* check for complete reassembly.
*/
if (p == NULL) {
LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
} else {
LIST_INSERT_AFTER(p, ipqe, ipqe_q);
}
next = 0;
for (p = NULL, q = LIST_FIRST(&fp->ipq_fragq); q != NULL;
p = q, q = LIST_NEXT(q, ipqe_q)) {
if (ntohs(q->ipqe_ip->ip_off) != next)
return (0);
next += ntohs(q->ipqe_ip->ip_len);
}
if (p->ipqe_mff)
return (0);
/*
* Reassembly is complete. Check for a bogus message size and
* concatenate fragments.
*/
q = LIST_FIRST(&fp->ipq_fragq);
ip = q->ipqe_ip;
if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
ipstat_inc(ips_toolong);
ip_freef(fp);
return (0);
}
m = q->ipqe_m;
t = m->m_next;
m->m_next = 0;
m_cat(m, t);
nq = LIST_NEXT(q, ipqe_q);
pool_put(&ipqent_pool, q);
ip_frags--;
for (q = nq; q != NULL; q = nq) {
t = q->ipqe_m;
nq = LIST_NEXT(q, ipqe_q);
pool_put(&ipqent_pool, q);
ip_frags--;
m_removehdr(t);
m_cat(m, t);
}
/*
* Create header for new ip packet by
* modifying header of first packet;
* dequeue and discard fragment reassembly header.
* Make header visible.
*/
ip->ip_len = htons(next);
ip->ip_src = fp->ipq_src;
ip->ip_dst = fp->ipq_dst;
LIST_REMOVE(fp, ipq_q);
pool_put(&ipq_pool, fp);
m->m_len += (ip->ip_hl << 2);
m->m_data -= (ip->ip_hl << 2);
m_calchdrlen(m);
return (m);
dropfrag:
ipstat_inc(ips_fragdropped);
m_freem(m);
pool_put(&ipqent_pool, ipqe);
ip_frags--;
return (NULL);
}
/*
* Free a fragment reassembly header and all
* associated datagrams.
*/
void
ip_freef(struct ipq *fp)
{
struct ipqent *q;
MUTEX_ASSERT_LOCKED(&ipq_mutex);
while ((q = LIST_FIRST(&fp->ipq_fragq)) != NULL) {
LIST_REMOVE(q, ipqe_q);
m_freem(q->ipqe_m);
pool_put(&ipqent_pool, q);
ip_frags--;
}
LIST_REMOVE(fp, ipq_q);
pool_put(&ipq_pool, fp);
}
/*
* IP timer processing;
* if a timer expires on a reassembly queue, discard it.
*/
void
ip_slowtimo(void)
{
struct ipq *fp, *nfp;
mtx_enter(&ipq_mutex);
LIST_FOREACH_SAFE(fp, &ipq, ipq_q, nfp) {
if (--fp->ipq_ttl == 0) {
ipstat_inc(ips_fragtimeout);
ip_freef(fp);
}
}
mtx_leave(&ipq_mutex);
}
/*
* Flush a bunch of datagram fragments, till we are down to 75%.
*/
void
ip_flush(void)
{
int max = 50;
MUTEX_ASSERT_LOCKED(&ipq_mutex);
while (!LIST_EMPTY(&ipq) && ip_frags > ip_maxqueue * 3 / 4 && --max) {
ipstat_inc(ips_fragdropped);
ip_freef(LIST_FIRST(&ipq));
}
}
/*
* Do option processing on a datagram,
* possibly discarding it if bad options are encountered,
* or forwarding it if source-routed.
* Returns 1 if packet has been forwarded/freed,
* 0 if the packet should be processed further.
*/
int
ip_dooptions(struct mbuf *m, struct ifnet *ifp)
{
struct ip *ip = mtod(m, struct ip *);
unsigned int rtableid = m->m_pkthdr.ph_rtableid;
struct rtentry *rt;
struct sockaddr_in ipaddr;
u_char *cp;
struct ip_timestamp ipt;
struct in_ifaddr *ia;
int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
struct in_addr sin, dst;
u_int32_t ntime;
dst = ip->ip_dst;
cp = (u_char *)(ip + 1);
cnt = (ip->ip_hl << 2) - sizeof (struct ip);
KERNEL_LOCK();
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:
if (!ip_dosourceroute) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
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;
}
memset(&ipaddr, 0, sizeof(ipaddr));
ipaddr.sin_family = AF_INET;
ipaddr.sin_len = sizeof(ipaddr);
ipaddr.sin_addr = ip->ip_dst;
ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr),
m->m_pkthdr.ph_rtableid));
if (ia == NULL) {
if (opt == IPOPT_SSRR) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
/*
* Loose routing, and not at next destination
* yet; nothing to do except forward.
*/
break;
}
off--; /* 0 origin */
if ((off + sizeof(struct in_addr)) > optlen) {
/*
* End of source route. Should be for us.
*/
save_rte(m, cp, ip->ip_src);
break;
}
/*
* locate outgoing interface
*/
memset(&ipaddr, 0, sizeof(ipaddr));
ipaddr.sin_family = AF_INET;
ipaddr.sin_len = sizeof(ipaddr);
memcpy(&ipaddr.sin_addr, cp + off,
sizeof(ipaddr.sin_addr));
/* keep packet in the virtual instance */
rt = rtalloc(sintosa(&ipaddr), RT_RESOLVE, rtableid);
if (!rtisvalid(rt) || ((opt == IPOPT_SSRR) &&
ISSET(rt->rt_flags, RTF_GATEWAY))) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
rtfree(rt);
goto bad;
}
ia = ifatoia(rt->rt_ifa);
memcpy(cp + off, &ia->ia_addr.sin_addr,
sizeof(struct in_addr));
rtfree(rt);
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
ip->ip_dst = ipaddr.sin_addr;
/*
* Let ip_intr's mcast routing check handle mcast pkts
*/
forward = !IN_MULTICAST(ip->ip_dst.s_addr);
break;
case IPOPT_RR:
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;
}
/*
* If no space remains, ignore.
*/
off--; /* 0 origin */
if ((off + sizeof(struct in_addr)) > optlen)
break;
memset(&ipaddr, 0, sizeof(ipaddr));
ipaddr.sin_family = AF_INET;
ipaddr.sin_len = sizeof(ipaddr);
ipaddr.sin_addr = ip->ip_dst;
/*
* locate outgoing interface; if we're the destination,
* use the incoming interface (should be same).
* Again keep the packet inside the virtual instance.
*/
rt = rtalloc(sintosa(&ipaddr), RT_RESOLVE, rtableid);
if (!rtisvalid(rt)) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
rtfree(rt);
goto bad;
}
ia = ifatoia(rt->rt_ifa);
memcpy(cp + off, &ia->ia_addr.sin_addr,
sizeof(struct in_addr));
rtfree(rt);
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
break;
case IPOPT_TS:
code = cp - (u_char *)ip;
if (optlen < sizeof(struct ip_timestamp))
goto bad;
memcpy(&ipt, cp, sizeof(struct ip_timestamp));
if (ipt.ipt_ptr < 5 || ipt.ipt_len < 5)
goto bad;
if (ipt.ipt_ptr - 1 + sizeof(u_int32_t) > ipt.ipt_len) {
if (++ipt.ipt_oflw == 0)
goto bad;
break;
}
memcpy(&sin, cp + ipt.ipt_ptr - 1, sizeof sin);
switch (ipt.ipt_flg) {
case IPOPT_TS_TSONLY:
break;
case IPOPT_TS_TSANDADDR:
if (ipt.ipt_ptr - 1 + sizeof(u_int32_t) +
sizeof(struct in_addr) > ipt.ipt_len)
goto bad;
memset(&ipaddr, 0, sizeof(ipaddr));
ipaddr.sin_family = AF_INET;
ipaddr.sin_len = sizeof(ipaddr);
ipaddr.sin_addr = dst;
ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
ifp));
if (ia == NULL)
continue;
memcpy(&sin, &ia->ia_addr.sin_addr,
sizeof(struct in_addr));
ipt.ipt_ptr += sizeof(struct in_addr);
break;
case IPOPT_TS_PRESPEC:
if (ipt.ipt_ptr - 1 + sizeof(u_int32_t) +
sizeof(struct in_addr) > ipt.ipt_len)
goto bad;
memset(&ipaddr, 0, sizeof(ipaddr));
ipaddr.sin_family = AF_INET;
ipaddr.sin_len = sizeof(ipaddr);
ipaddr.sin_addr = sin;
if (ifa_ifwithaddr(sintosa(&ipaddr),
m->m_pkthdr.ph_rtableid) == NULL)
continue;
ipt.ipt_ptr += sizeof(struct in_addr);
break;
default:
/* XXX can't take &ipt->ipt_flg */
code = (u_char *)&ipt.ipt_ptr -
(u_char *)ip + 1;
goto bad;
}
ntime = iptime();
memcpy(cp + ipt.ipt_ptr - 1, &ntime, sizeof(u_int32_t));
ipt.ipt_ptr += sizeof(u_int32_t);
}
}
KERNEL_UNLOCK();
if (forward && ipforwarding > 0) {
ip_forward(m, ifp, NULL, 1);
return (1);
}
return (0);
bad:
KERNEL_UNLOCK();
icmp_error(m, type, code, 0, 0);
ipstat_inc(ips_badoptions);
return (1);
}
/*
* Save incoming source route for use in replies,
* to be picked up later by ip_srcroute if the receiver is interested.
*/
void
save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
{
struct ip_srcrt *isr;
struct m_tag *mtag;
unsigned olen;
olen = option[IPOPT_OLEN];
if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes))
return;
mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT);
if (mtag == NULL) {
ipstat_inc(ips_idropped);
return;
}
isr = (struct ip_srcrt *)(mtag + 1);
memcpy(isr->isr_hdr, option, olen);
isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
isr->isr_dst = dst;
m_tag_prepend(m, mtag);
}
/*
* Retrieve incoming source route for use in replies,
* in the same form used by setsockopt.
* The first hop is placed before the options, will be removed later.
*/
struct mbuf *
ip_srcroute(struct mbuf *m0)
{
struct in_addr *p, *q;
struct mbuf *m;
struct ip_srcrt *isr;
struct m_tag *mtag;
if (!ip_dosourceroute)
return (NULL);
mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE, NULL);
if (mtag == NULL)
return (NULL);
isr = (struct ip_srcrt *)(mtag + 1);
if (isr->isr_nhops == 0)
return (NULL);
m = m_get(M_DONTWAIT, MT_SOOPTS);
if (m == NULL) {
ipstat_inc(ips_idropped);
return (NULL);
}
#define OPTSIZ (sizeof(isr->isr_nop) + sizeof(isr->isr_hdr))
/* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */
m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ;
/*
* First save first hop for return route
*/
p = &(isr->isr_routes[isr->isr_nhops - 1]);
*(mtod(m, struct in_addr *)) = *p--;
/*
* Copy option fields and padding (nop) to mbuf.
*/
isr->isr_nop = IPOPT_NOP;
isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF;
memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &isr->isr_nop,
OPTSIZ);
q = (struct in_addr *)(mtod(m, caddr_t) +
sizeof(struct in_addr) + OPTSIZ);
#undef OPTSIZ
/*
* Record return path as an IP source route,
* reversing the path (pointers are now aligned).
*/
while (p >= isr->isr_routes) {
*q++ = *p--;
}
/*
* Last hop goes to final destination.
*/
*q = isr->isr_dst;
m_tag_delete(m0, (struct m_tag *)isr);
return (m);
}
/*
* Strip out IP options, at higher level protocol in the kernel.
*/
void
ip_stripoptions(struct mbuf *m)
{
int i;
struct ip *ip = mtod(m, struct ip *);
caddr_t opts;
int olen;
olen = (ip->ip_hl<<2) - sizeof (struct ip);
opts = (caddr_t)(ip + 1);
i = m->m_len - (sizeof (struct ip) + olen);
memmove(opts, opts + olen, i);
m->m_len -= olen;
if (m->m_flags & M_PKTHDR)
m->m_pkthdr.len -= olen;
ip->ip_hl = sizeof(struct ip) >> 2;
ip->ip_len = htons(ntohs(ip->ip_len) - olen);
}
const u_char inetctlerrmap[PRC_NCMDS] = {
0, 0, 0, 0,
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
EMSGSIZE, EHOSTUNREACH, 0, 0,
0, 0, 0, 0,
ENOPROTOOPT
};
/*
* Forward a packet. If some error occurs return the sender
* an icmp packet. Note we can't always generate a meaningful
* icmp message because icmp doesn't have a large enough repertoire
* of codes and types.
*
* If not forwarding, just drop the packet. This could be confusing
* if ipforwarding was zero but some routing protocol was advancing
* us as a gateway to somewhere. However, we must let the routing
* protocol deal with that.
*
* The srcrt parameter indicates whether the packet is being forwarded
* via a source route.
*/
void
ip_forward(struct mbuf *m, struct ifnet *ifp, struct route *ro, int srcrt)
{
struct mbuf mfake, *mcopy;
struct ip *ip = mtod(m, struct ip *);
struct route iproute;
struct rtentry *rt;
int error = 0, type = 0, code = 0, destmtu = 0, fake = 0, len;
u_int32_t dest;
dest = 0;
if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
ipstat_inc(ips_cantforward);
m_freem(m);
goto done;
}
if (ip->ip_ttl <= IPTTLDEC) {
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
goto done;
}
if (ro == NULL) {
ro = &iproute;
ro->ro_rt = NULL;
}
rt = route_mpath(ro, &ip->ip_dst, &ip->ip_src, m->m_pkthdr.ph_rtableid);
if (rt == NULL) {
ipstat_inc(ips_noroute);
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
goto done;
}
/*
* Save at most 68 bytes of the packet in case
* we need to generate an ICMP message to the src.
* The data is saved in the mbuf on the stack that
* acts as a temporary storage not intended to be
* passed down the IP stack or to the mfree.
*/
memset(&mfake.m_hdr, 0, sizeof(mfake.m_hdr));
mfake.m_type = m->m_type;
if (m_dup_pkthdr(&mfake, m, M_DONTWAIT) == 0) {
mfake.m_data = mfake.m_pktdat;
len = min(ntohs(ip->ip_len), 68);
m_copydata(m, 0, len, mfake.m_pktdat);
mfake.m_pkthdr.len = mfake.m_len = len;
#if NPF > 0
pf_pkt_addr_changed(&mfake);
#endif /* NPF > 0 */
fake = 1;
}
ip->ip_ttl -= IPTTLDEC;
/*
* If forwarding packet using same interface that it came in on,
* perhaps should send a redirect to sender to shortcut a hop.
* Only send redirect if source is sending directly to us,
* and if packet was not source routed (or has any options).
* Also, don't send redirect if forwarding using a default route
* or a route modified by a redirect.
* Don't send redirect if we advertise destination's arp address
* as ours (proxy arp).
*/
if ((rt->rt_ifidx == ifp->if_index) &&
(rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
ipsendredirects && !srcrt &&
!arpproxy(satosin(rt_key(rt))->sin_addr, m->m_pkthdr.ph_rtableid)) {
if ((ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_netmask) ==
ifatoia(rt->rt_ifa)->ia_net) {
if (rt->rt_flags & RTF_GATEWAY)
dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
else
dest = ip->ip_dst.s_addr;
/* Router requirements says to only send host redirects */
type = ICMP_REDIRECT;
code = ICMP_REDIRECT_HOST;
}
}
error = ip_output(m, NULL, ro,
(IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
NULL, NULL, 0);
rt = ro->ro_rt;
if (error)
ipstat_inc(ips_cantforward);
else {
ipstat_inc(ips_forward);
if (type)
ipstat_inc(ips_redirectsent);
else
goto done;
}
if (!fake)
goto done;
switch (error) {
case 0: /* forwarded, but need redirect */
/* type, code set above */
break;
case EMSGSIZE:
type = ICMP_UNREACH;
code = ICMP_UNREACH_NEEDFRAG;
if (rt != NULL) {
if (rt->rt_mtu) {
destmtu = rt->rt_mtu;
} else {
struct ifnet *destifp;
destifp = if_get(rt->rt_ifidx);
if (destifp != NULL)
destmtu = destifp->if_mtu;
if_put(destifp);
}
}
ipstat_inc(ips_cantfrag);
if (destmtu == 0)
goto done;
break;
case EACCES:
/*
* pf(4) blocked the packet. There is no need to send an ICMP
* packet back since pf(4) takes care of it.
*/
goto done;
case ENOBUFS:
/*
* a router should not generate ICMP_SOURCEQUENCH as
* required in RFC1812 Requirements for IP Version 4 Routers.
* source quench could be a big problem under DoS attacks,
* or the underlying interface is rate-limited.
*/
goto done;
case ENETUNREACH: /* shouldn't happen, checked above */
case EHOSTUNREACH:
case ENETDOWN:
case EHOSTDOWN:
default:
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
break;
}
mcopy = m_copym(&mfake, 0, len, M_DONTWAIT);
if (mcopy != NULL)
icmp_error(mcopy, type, code, dest, destmtu);
done:
if (ro == &iproute)
rtfree(ro->ro_rt);
if (fake)
m_tag_delete_chain(&mfake);
}
int
ip_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
size_t newlen)
{
#ifdef MROUTING
extern struct mrtstat mrtstat;
#endif
int oldval, error;
/* Almost all sysctl names at this level are terminal. */
if (namelen != 1 && name[0] != IPCTL_IFQUEUE &&
name[0] != IPCTL_ARPQUEUE)
return (ENOTDIR);
switch (name[0]) {
case IPCTL_SOURCEROUTE:
NET_LOCK();
error = sysctl_securelevel_int(oldp, oldlenp, newp, newlen,
&ip_dosourceroute);
NET_UNLOCK();
return (error);
case IPCTL_MTUDISC:
NET_LOCK();
error = sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtudisc);
if (ip_mtudisc == 0)
rt_timer_queue_flush(&ip_mtudisc_timeout_q);
NET_UNLOCK();
return error;
case IPCTL_MTUDISCTIMEOUT:
NET_LOCK();
error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
&ip_mtudisc_timeout, 0, INT_MAX);
rt_timer_queue_change(&ip_mtudisc_timeout_q,
ip_mtudisc_timeout);
NET_UNLOCK();
return (error);
#ifdef IPSEC
case IPCTL_ENCDEBUG:
case IPCTL_IPSEC_STATS:
case IPCTL_IPSEC_EXPIRE_ACQUIRE:
case IPCTL_IPSEC_EMBRYONIC_SA_TIMEOUT:
case IPCTL_IPSEC_REQUIRE_PFS:
case IPCTL_IPSEC_SOFT_ALLOCATIONS:
case IPCTL_IPSEC_ALLOCATIONS:
case IPCTL_IPSEC_SOFT_BYTES:
case IPCTL_IPSEC_BYTES:
case IPCTL_IPSEC_TIMEOUT:
case IPCTL_IPSEC_SOFT_TIMEOUT:
case IPCTL_IPSEC_SOFT_FIRSTUSE:
case IPCTL_IPSEC_FIRSTUSE:
case IPCTL_IPSEC_ENC_ALGORITHM:
case IPCTL_IPSEC_AUTH_ALGORITHM:
case IPCTL_IPSEC_IPCOMP_ALGORITHM:
return (ipsec_sysctl(name, namelen, oldp, oldlenp, newp,
newlen));
#endif
case IPCTL_IFQUEUE:
return (sysctl_niq(name + 1, namelen - 1,
oldp, oldlenp, newp, newlen, &ipintrq));
case IPCTL_ARPQUEUE:
return (sysctl_niq(name + 1, namelen - 1,
oldp, oldlenp, newp, newlen, &arpinq));
case IPCTL_ARPQUEUED:
return (sysctl_rdint(oldp, oldlenp, newp,
atomic_load_int(&la_hold_total)));
case IPCTL_STATS:
return (ip_sysctl_ipstat(oldp, oldlenp, newp));
#ifdef MROUTING
case IPCTL_MRTSTATS:
return (sysctl_rdstruct(oldp, oldlenp, newp,
&mrtstat, sizeof(mrtstat)));
case IPCTL_MRTMFC:
if (newp)
return (EPERM);
NET_LOCK();
error = mrt_sysctl_mfc(oldp, oldlenp);
NET_UNLOCK();
return (error);
case IPCTL_MRTVIF:
if (newp)
return (EPERM);
NET_LOCK();
error = mrt_sysctl_vif(oldp, oldlenp);
NET_UNLOCK();
return (error);
#else
case IPCTL_MRTPROTO:
case IPCTL_MRTSTATS:
case IPCTL_MRTMFC:
case IPCTL_MRTVIF:
return (EOPNOTSUPP);
#endif
case IPCTL_MULTIPATH:
NET_LOCK();
oldval = ipmultipath;
error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
&ipmultipath, 0, 1);
if (oldval != ipmultipath)
atomic_inc_long(&rtgeneration);
NET_UNLOCK();
return (error);
default:
NET_LOCK();
error = sysctl_bounded_arr(ipctl_vars, nitems(ipctl_vars),
name, namelen, oldp, oldlenp, newp, newlen);
NET_UNLOCK();
return (error);
}
/* NOTREACHED */
}
int
ip_sysctl_ipstat(void *oldp, size_t *oldlenp, void *newp)
{
uint64_t counters[ips_ncounters];
struct ipstat ipstat;
u_long *words = (u_long *)&ipstat;
int i;
CTASSERT(sizeof(ipstat) == (nitems(counters) * sizeof(u_long)));
memset(&ipstat, 0, sizeof ipstat);
counters_read(ipcounters, counters, nitems(counters), NULL);
for (i = 0; i < nitems(counters); i++)
words[i] = (u_long)counters[i];
return (sysctl_rdstruct(oldp, oldlenp, newp, &ipstat, sizeof(ipstat)));
}
void
ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
struct mbuf *m)
{
if (inp->inp_socket->so_options & SO_TIMESTAMP) {
struct timeval tv;
m_microtime(m, &tv);
*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
SCM_TIMESTAMP, SOL_SOCKET);
if (*mp)
mp = &(*mp)->m_next;
}
if (inp->inp_flags & INP_RECVDSTADDR) {
*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
#ifdef notyet
/* this code is broken and will probably never be fixed. */
/* options were tossed already */
if (inp->inp_flags & INP_RECVOPTS) {
*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
/* ip_srcroute doesn't do what we want here, need to fix */
if (inp->inp_flags & INP_RECVRETOPTS) {
*mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
#endif
if (inp->inp_flags & INP_RECVIF) {
struct sockaddr_dl sdl;
struct ifnet *ifp;
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL || ifp->if_sadl == NULL) {
memset(&sdl, 0, sizeof(sdl));
sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
sdl.sdl_family = AF_LINK;
sdl.sdl_index = ifp != NULL ? ifp->if_index : 0;
sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
*mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
IP_RECVIF, IPPROTO_IP);
} else {
*mp = sbcreatecontrol((caddr_t) ifp->if_sadl,
ifp->if_sadl->sdl_len, IP_RECVIF, IPPROTO_IP);
}
if (*mp)
mp = &(*mp)->m_next;
if_put(ifp);
}
if (inp->inp_flags & INP_RECVTTL) {
*mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
sizeof(u_int8_t), IP_RECVTTL, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
if (inp->inp_flags & INP_RECVRTABLE) {
u_int rtableid = inp->inp_rtableid;
#if NPF > 0
if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
struct pf_divert *divert;
divert = pf_find_divert(m);
KASSERT(divert != NULL);
rtableid = divert->rdomain;
}
#endif
*mp = sbcreatecontrol((caddr_t) &rtableid,
sizeof(u_int), IP_RECVRTABLE, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
}
void
ip_send_do_dispatch(void *xmq, int flags)
{
struct mbuf_queue *mq = xmq;
struct mbuf *m;
struct mbuf_list ml;
struct m_tag *mtag;
mq_delist(mq, &ml);
if (ml_empty(&ml))
return;
NET_LOCK_SHARED();
while ((m = ml_dequeue(&ml)) != NULL) {
u_int32_t ipsecflowinfo = 0;
if ((mtag = m_tag_find(m, PACKET_TAG_IPSEC_FLOWINFO, NULL))
!= NULL) {
ipsecflowinfo = *(u_int32_t *)(mtag + 1);
m_tag_delete(m, mtag);
}
ip_output(m, NULL, NULL, flags, NULL, NULL, ipsecflowinfo);
}
NET_UNLOCK_SHARED();
}
void
ip_sendraw_dispatch(void *xmq)
{
ip_send_do_dispatch(xmq, IP_RAWOUTPUT);
}
void
ip_send_dispatch(void *xmq)
{
ip_send_do_dispatch(xmq, 0);
}
void
ip_send(struct mbuf *m)
{
mq_enqueue(&ipsend_mq, m);
task_add(net_tq(0), &ipsend_task);
}
void
ip_send_raw(struct mbuf *m)
{
mq_enqueue(&ipsendraw_mq, m);
task_add(net_tq(0), &ipsendraw_task);
}
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