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freebsd/sys/netinet/ip_output.c
Maxim Konovalov cb7641e85b Slightly rearrange a code in rev. 1.164: 
o Move len initialization closer to place of its first usage.
o Compare len with 0 to improve readability.
o Explicitly zero out phlen in ip_insertoptions() in failure case.

Suggested by:   jhb
Reviewed by:    jhb
MFC after:      2 weeks
2002-09-23 08:56:24 +00:00

2066 lines
50 KiB
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/*
* Copyright (c) 1982, 1986, 1988, 1990, 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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_output.c 8.3 (Berkeley) 1/21/94
* $FreeBSD$
*/
#define _IP_VHL
#include "opt_ipfw.h"
#include "opt_ipdn.h"
#include "opt_ipdivert.h"
#include "opt_ipfilter.h"
#include "opt_ipsec.h"
#include "opt_mac.h"
#include "opt_pfil_hooks.h"
#include "opt_random_ip_id.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <machine/in_cksum.h>
static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
#ifdef IPSEC
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#ifdef IPSEC_DEBUG
#include <netkey/key_debug.h>
#else
#define KEYDEBUG(lev,arg)
#endif
#endif /*IPSEC*/
#include <netinet/ip_fw.h>
#include <netinet/ip_dummynet.h>
#define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\
x, (ntohl(a.s_addr)>>24)&0xFF,\
(ntohl(a.s_addr)>>16)&0xFF,\
(ntohl(a.s_addr)>>8)&0xFF,\
(ntohl(a.s_addr))&0xFF, y);
u_short ip_id;
static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
static struct ifnet *ip_multicast_if(struct in_addr *, int *);
static void ip_mloopback
(struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
static int ip_getmoptions
(struct sockopt *, struct ip_moptions *);
static int ip_pcbopts(int, struct mbuf **, struct mbuf *);
static int ip_setmoptions
(struct sockopt *, struct ip_moptions **);
int ip_optcopy(struct ip *, struct ip *);
extern struct protosw inetsw[];
/*
* IP output. The packet in mbuf chain m contains a skeletal IP
* header (with len, off, ttl, proto, tos, src, dst).
* The mbuf chain containing the packet will be freed.
* The mbuf opt, if present, will not be freed.
*/
int
ip_output(m0, opt, ro, flags, imo)
struct mbuf *m0;
struct mbuf *opt;
struct route *ro;
int flags;
struct ip_moptions *imo;
{
struct ip *ip, *mhip;
struct ifnet *ifp = NULL; /* keep compiler happy */
struct mbuf *m;
int hlen = sizeof (struct ip);
int len, off, error = 0;
struct sockaddr_in *dst = NULL; /* keep compiler happy */
struct in_ifaddr *ia = NULL;
int isbroadcast, sw_csum;
struct in_addr pkt_dst;
#ifdef IPSEC
struct route iproute;
struct socket *so = NULL;
struct secpolicy *sp = NULL;
#endif
struct ip_fw_args args;
int src_was_INADDR_ANY = 0; /* as the name says... */
#ifdef PFIL_HOOKS
struct packet_filter_hook *pfh;
struct mbuf *m1;
int rv;
#endif /* PFIL_HOOKS */
args.eh = NULL;
args.rule = NULL;
args.next_hop = NULL;
args.divert_rule = 0; /* divert cookie */
/* Grab info from MT_TAG mbufs prepended to the chain. */
for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) {
switch(m0->m_tag_id) {
default:
printf("ip_output: unrecognised MT_TAG tag %d\n",
m0->m_tag_id);
break;
case PACKET_TAG_DUMMYNET:
/*
* the packet was already tagged, so part of the
* processing was already done, and we need to go down.
* Get parameters from the header.
*/
args.rule = ((struct dn_pkt *)m0)->rule;
opt = NULL ;
ro = & ( ((struct dn_pkt *)m0)->ro ) ;
imo = NULL ;
dst = ((struct dn_pkt *)m0)->dn_dst ;
ifp = ((struct dn_pkt *)m0)->ifp ;
flags = ((struct dn_pkt *)m0)->flags ;
break;
case PACKET_TAG_DIVERT:
args.divert_rule = (intptr_t)m0->m_data & 0xffff;
break;
case PACKET_TAG_IPFORWARD:
args.next_hop = (struct sockaddr_in *)m0->m_data;
break;
}
}
m = m0;
KASSERT(!m || (m->m_flags & M_PKTHDR) != 0, ("ip_output: no HDR"));
KASSERT(ro != NULL, ("ip_output: no route, proto %d",
mtod(m, struct ip *)->ip_p));
#ifdef IPSEC
so = ipsec_getsocket(m);
(void)ipsec_setsocket(m, NULL);
#endif
if (args.rule != NULL) { /* dummynet already saw us */
ip = mtod(m, struct ip *);
hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
if (ro->ro_rt)
ia = ifatoia(ro->ro_rt->rt_ifa);
goto sendit;
}
if (opt) {
len = 0;
m = ip_insertoptions(m, opt, &len);
if (len != 0)
hlen = len;
}
ip = mtod(m, struct ip *);
pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
/*
* Fill in IP header.
*/
if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
ip->ip_off &= IP_DF;
#ifdef RANDOM_IP_ID
ip->ip_id = ip_randomid();
#else
ip->ip_id = htons(ip_id++);
#endif
ipstat.ips_localout++;
} else {
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
}
dst = (struct sockaddr_in *)&ro->ro_dst;
/*
* If there is a cached route,
* check that it is to the same destination
* and is still up. If not, free it and try again.
* The address family should also be checked in case of sharing the
* cache with IPv6.
*/
if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
dst->sin_family != AF_INET ||
dst->sin_addr.s_addr != pkt_dst.s_addr)) {
RTFREE(ro->ro_rt);
ro->ro_rt = (struct rtentry *)0;
}
if (ro->ro_rt == 0) {
bzero(dst, sizeof(*dst));
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = pkt_dst;
}
/*
* If routing to interface only,
* short circuit routing lookup.
*/
if (flags & IP_ROUTETOIF) {
if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 &&
(ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) {
ipstat.ips_noroute++;
error = ENETUNREACH;
goto bad;
}
ifp = ia->ia_ifp;
ip->ip_ttl = 1;
isbroadcast = in_broadcast(dst->sin_addr, ifp);
} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
imo != NULL && imo->imo_multicast_ifp != NULL) {
/*
* Bypass the normal routing lookup for multicast
* packets if the interface is specified.
*/
ifp = imo->imo_multicast_ifp;
IFP_TO_IA(ifp, ia);
isbroadcast = 0; /* fool gcc */
} else {
/*
* If this is the case, we probably don't want to allocate
* a protocol-cloned route since we didn't get one from the
* ULP. This lets TCP do its thing, while not burdening
* forwarding or ICMP with the overhead of cloning a route.
* Of course, we still want to do any cloning requested by
* the link layer, as this is probably required in all cases
* for correct operation (as it is for ARP).
*/
if (ro->ro_rt == 0)
rtalloc_ign(ro, RTF_PRCLONING);
if (ro->ro_rt == 0) {
ipstat.ips_noroute++;
error = EHOSTUNREACH;
goto bad;
}
ia = ifatoia(ro->ro_rt->rt_ifa);
ifp = ro->ro_rt->rt_ifp;
ro->ro_rt->rt_use++;
if (ro->ro_rt->rt_flags & RTF_GATEWAY)
dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
if (ro->ro_rt->rt_flags & RTF_HOST)
isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
else
isbroadcast = in_broadcast(dst->sin_addr, ifp);
}
if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
struct in_multi *inm;
m->m_flags |= M_MCAST;
/*
* IP destination address is multicast. Make sure "dst"
* still points to the address in "ro". (It may have been
* changed to point to a gateway address, above.)
*/
dst = (struct sockaddr_in *)&ro->ro_dst;
/*
* See if the caller provided any multicast options
*/
if (imo != NULL) {
ip->ip_ttl = imo->imo_multicast_ttl;
if (imo->imo_multicast_vif != -1)
ip->ip_src.s_addr =
ip_mcast_src(imo->imo_multicast_vif);
} else
ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
/*
* Confirm that the outgoing interface supports multicast.
*/
if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
if ((ifp->if_flags & IFF_MULTICAST) == 0) {
ipstat.ips_noroute++;
error = ENETUNREACH;
goto bad;
}
}
/*
* If source address not specified yet, use address
* of outgoing interface.
*/
if (ip->ip_src.s_addr == INADDR_ANY) {
/* Interface may have no addresses. */
if (ia != NULL)
ip->ip_src = IA_SIN(ia)->sin_addr;
}
if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
/*
* XXX
* delayed checksums are not currently
* compatible with IP multicast routing
*/
if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &=
~CSUM_DELAY_DATA;
}
}
IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
if (inm != NULL &&
(imo == NULL || imo->imo_multicast_loop)) {
/*
* If we belong to the destination multicast group
* on the outgoing interface, and the caller did not
* forbid loopback, loop back a copy.
*/
ip_mloopback(ifp, m, dst, hlen);
}
else {
/*
* If we are acting as a multicast router, perform
* multicast forwarding as if the packet had just
* arrived on the interface to which we are about
* to send. The multicast forwarding function
* recursively calls this function, using the
* IP_FORWARDING flag to prevent infinite recursion.
*
* Multicasts that are looped back by ip_mloopback(),
* above, will be forwarded by the ip_input() routine,
* if necessary.
*/
if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
/*
* Check if rsvp daemon is running. If not, don't
* set ip_moptions. This ensures that the packet
* is multicast and not just sent down one link
* as prescribed by rsvpd.
*/
if (!rsvp_on)
imo = NULL;
if (ip_mforward(ip, ifp, m, imo) != 0) {
m_freem(m);
goto done;
}
}
}
/*
* Multicasts with a time-to-live of zero may be looped-
* back, above, but must not be transmitted on a network.
* Also, multicasts addressed to the loopback interface
* are not sent -- the above call to ip_mloopback() will
* loop back a copy if this host actually belongs to the
* destination group on the loopback interface.
*/
if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
m_freem(m);
goto done;
}
goto sendit;
}
#ifndef notdef
/*
* If the source address is not specified yet, use the address
* of the outoing interface. In case, keep note we did that, so
* if the the firewall changes the next-hop causing the output
* interface to change, we can fix that.
*/
if (ip->ip_src.s_addr == INADDR_ANY) {
/* Interface may have no addresses. */
if (ia != NULL) {
ip->ip_src = IA_SIN(ia)->sin_addr;
src_was_INADDR_ANY = 1;
}
}
#endif /* notdef */
/*
* Verify that we have any chance at all of being able to queue
* the packet or packet fragments
*/
if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
ifp->if_snd.ifq_maxlen) {
error = ENOBUFS;
ipstat.ips_odropped++;
goto bad;
}
/*
* Look for broadcast address and
* verify user is allowed to send
* such a packet.
*/
if (isbroadcast) {
if ((ifp->if_flags & IFF_BROADCAST) == 0) {
error = EADDRNOTAVAIL;
goto bad;
}
if ((flags & IP_ALLOWBROADCAST) == 0) {
error = EACCES;
goto bad;
}
/* don't allow broadcast messages to be fragmented */
if ((u_short)ip->ip_len > ifp->if_mtu) {
error = EMSGSIZE;
goto bad;
}
m->m_flags |= M_BCAST;
} else {
m->m_flags &= ~M_BCAST;
}
sendit:
#ifdef IPSEC
/* get SP for this packet */
if (so == NULL)
sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
else
sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
if (sp == NULL) {
ipsecstat.out_inval++;
goto bad;
}
error = 0;
/* check policy */
switch (sp->policy) {
case IPSEC_POLICY_DISCARD:
/*
* This packet is just discarded.
*/
ipsecstat.out_polvio++;
goto bad;
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_NONE:
/* no need to do IPsec. */
goto skip_ipsec;
case IPSEC_POLICY_IPSEC:
if (sp->req == NULL) {
/* acquire a policy */
error = key_spdacquire(sp);
goto bad;
}
break;
case IPSEC_POLICY_ENTRUST:
default:
printf("ip_output: Invalid policy found. %d\n", sp->policy);
}
{
struct ipsec_output_state state;
bzero(&state, sizeof(state));
state.m = m;
if (flags & IP_ROUTETOIF) {
state.ro = &iproute;
bzero(&iproute, sizeof(iproute));
} else
state.ro = ro;
state.dst = (struct sockaddr *)dst;
ip->ip_sum = 0;
/*
* XXX
* delayed checksums are not currently compatible with IPsec
*/
if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
error = ipsec4_output(&state, sp, flags);
m = state.m;
if (flags & IP_ROUTETOIF) {
/*
* if we have tunnel mode SA, we may need to ignore
* IP_ROUTETOIF.
*/
if (state.ro != &iproute || state.ro->ro_rt != NULL) {
flags &= ~IP_ROUTETOIF;
ro = state.ro;
}
} else
ro = state.ro;
dst = (struct sockaddr_in *)state.dst;
if (error) {
/* mbuf is already reclaimed in ipsec4_output. */
m0 = NULL;
switch (error) {
case EHOSTUNREACH:
case ENETUNREACH:
case EMSGSIZE:
case ENOBUFS:
case ENOMEM:
break;
default:
printf("ip4_output (ipsec): error code %d\n", error);
/*fall through*/
case ENOENT:
/* don't show these error codes to the user */
error = 0;
break;
}
goto bad;
}
}
/* be sure to update variables that are affected by ipsec4_output() */
ip = mtod(m, struct ip *);
#ifdef _IP_VHL
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
hlen = ip->ip_hl << 2;
#endif
if (ro->ro_rt == NULL) {
if ((flags & IP_ROUTETOIF) == 0) {
printf("ip_output: "
"can't update route after IPsec processing\n");
error = EHOSTUNREACH; /*XXX*/
goto bad;
}
} else {
ia = ifatoia(ro->ro_rt->rt_ifa);
ifp = ro->ro_rt->rt_ifp;
}
/* make it flipped, again. */
ip->ip_len = ntohs(ip->ip_len);
ip->ip_off = ntohs(ip->ip_off);
skip_ipsec:
#endif /*IPSEC*/
/*
* IpHack's section.
* - Xlate: translate packet's addr/port (NAT).
* - Firewall: deny/allow/etc.
* - Wrap: fake packet's addr/port <unimpl.>
* - Encapsulate: put it in another IP and send out. <unimp.>
*/
#ifdef PFIL_HOOKS
/*
* Run through list of hooks for output packets.
*/
m1 = m;
pfh = pfil_hook_get(PFIL_OUT, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh);
for (; pfh; pfh = TAILQ_NEXT(pfh, pfil_link))
if (pfh->pfil_func) {
rv = pfh->pfil_func(ip, hlen, ifp, 1, &m1);
if (rv) {
error = EHOSTUNREACH;
goto done;
}
m = m1;
if (m == NULL)
goto done;
ip = mtod(m, struct ip *);
}
#endif /* PFIL_HOOKS */
/*
* Check with the firewall...
* but not if we are already being fwd'd from a firewall.
*/
if (fw_enable && IPFW_LOADED && !args.next_hop) {
struct sockaddr_in *old = dst;
args.m = m;
args.next_hop = dst;
args.oif = ifp;
off = ip_fw_chk_ptr(&args);
m = args.m;
dst = args.next_hop;
/*
* On return we must do the following:
* m == NULL -> drop the pkt (old interface, deprecated)
* (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface)
* 1<=off<= 0xffff -> DIVERT
* (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe
* (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet
* dst != old -> IPFIREWALL_FORWARD
* off==0, dst==old -> accept
* If some of the above modules are not compiled in, then
* we should't have to check the corresponding condition
* (because the ipfw control socket should not accept
* unsupported rules), but better play safe and drop
* packets in case of doubt.
*/
if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) {
if (m)
m_freem(m);
error = EACCES;
goto done;
}
ip = mtod(m, struct ip *);
if (off == 0 && dst == old) /* common case */
goto pass;
if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) {
/*
* pass the pkt to dummynet. Need to include
* pipe number, m, ifp, ro, dst because these are
* not recomputed in the next pass.
* All other parameters have been already used and
* so they are not needed anymore.
* XXX note: if the ifp or ro entry are deleted
* while a pkt is in dummynet, we are in trouble!
*/
args.ro = ro;
args.dst = dst;
args.flags = flags;
error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT,
&args);
goto done;
}
#ifdef IPDIVERT
if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) {
struct mbuf *clone = NULL;
/* Clone packet if we're doing a 'tee' */
if ((off & IP_FW_PORT_TEE_FLAG) != 0)
clone = m_dup(m, M_DONTWAIT);
/*
* XXX
* delayed checksums are not currently compatible
* with divert sockets.
*/
if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
/* Restore packet header fields to original values */
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
/* Deliver packet to divert input routine */
divert_packet(m, 0, off & 0xffff, args.divert_rule);
/* If 'tee', continue with original packet */
if (clone != NULL) {
m = clone;
ip = mtod(m, struct ip *);
goto pass;
}
goto done;
}
#endif
/* IPFIREWALL_FORWARD */
/*
* Check dst to make sure it is directly reachable on the
* interface we previously thought it was.
* If it isn't (which may be likely in some situations) we have
* to re-route it (ie, find a route for the next-hop and the
* associated interface) and set them here. This is nested
* forwarding which in most cases is undesirable, except where
* such control is nigh impossible. So we do it here.
* And I'm babbling.
*/
if (off == 0 && old != dst) { /* FORWARD, dst has changed */
#if 0
/*
* XXX To improve readability, this block should be
* changed into a function call as below:
*/
error = ip_ipforward(&m, &dst, &ifp);
if (error)
goto bad;
if (m == NULL) /* ip_input consumed the mbuf */
goto done;
#else
struct in_ifaddr *ia;
/*
* XXX sro_fwd below is static, and a pointer
* to it gets passed to routines downstream.
* This could have surprisingly bad results in
* practice, because its content is overwritten
* by subsequent packets.
*/
/* There must be a better way to do this next line... */
static struct route sro_fwd;
struct route *ro_fwd = &sro_fwd;
#if 0
print_ip("IPFIREWALL_FORWARD: New dst ip: ",
dst->sin_addr, "\n");
#endif
/*
* We need to figure out if we have been forwarded
* to a local socket. If so, then we should somehow
* "loop back" to ip_input, and get directed to the
* PCB as if we had received this packet. This is
* because it may be dificult to identify the packets
* you want to forward until they are being output
* and have selected an interface. (e.g. locally
* initiated packets) If we used the loopback inteface,
* we would not be able to control what happens
* as the packet runs through ip_input() as
* it is done through a ISR.
*/
LIST_FOREACH(ia,
INADDR_HASH(dst->sin_addr.s_addr), ia_hash) {
/*
* If the addr to forward to is one
* of ours, we pretend to
* be the destination for this packet.
*/
if (IA_SIN(ia)->sin_addr.s_addr ==
dst->sin_addr.s_addr)
break;
}
if (ia) { /* tell ip_input "dont filter" */
struct m_hdr tag;
tag.mh_type = MT_TAG;
tag.mh_flags = PACKET_TAG_IPFORWARD;
tag.mh_data = (caddr_t)args.next_hop;
tag.mh_next = m;
if (m->m_pkthdr.rcvif == NULL)
m->m_pkthdr.rcvif = ifunit("lo0");
if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
m->m_pkthdr.csum_flags |=
CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
m0->m_pkthdr.csum_data = 0xffff;
}
m->m_pkthdr.csum_flags |=
CSUM_IP_CHECKED | CSUM_IP_VALID;
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
ip_input((struct mbuf *)&tag);
goto done;
}
/* Some of the logic for this was
* nicked from above.
*
* This rewrites the cached route in a local PCB.
* Is this what we want to do?
*/
bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst));
ro_fwd->ro_rt = 0;
rtalloc_ign(ro_fwd, RTF_PRCLONING);
if (ro_fwd->ro_rt == 0) {
ipstat.ips_noroute++;
error = EHOSTUNREACH;
goto bad;
}
ia = ifatoia(ro_fwd->ro_rt->rt_ifa);
ifp = ro_fwd->ro_rt->rt_ifp;
ro_fwd->ro_rt->rt_use++;
if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
dst = (struct sockaddr_in *)
ro_fwd->ro_rt->rt_gateway;
if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
isbroadcast =
(ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
else
isbroadcast = in_broadcast(dst->sin_addr, ifp);
if (ro->ro_rt)
RTFREE(ro->ro_rt);
ro->ro_rt = ro_fwd->ro_rt;
dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
#endif /* ... block to be put into a function */
/*
* If we added a default src ip earlier,
* which would have been gotten from the-then
* interface, do it again, from the new one.
*/
if (src_was_INADDR_ANY)
ip->ip_src = IA_SIN(ia)->sin_addr;
goto pass ;
}
/*
* if we get here, none of the above matches, and
* we have to drop the pkt
*/
m_freem(m);
error = EACCES; /* not sure this is the right error msg */
goto done;
}
pass:
/* 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.ips_badaddr++;
error = EADDRNOTAVAIL;
goto bad;
}
}
m->m_pkthdr.csum_flags |= CSUM_IP;
sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
if (sw_csum & CSUM_DELAY_DATA) {
in_delayed_cksum(m);
sw_csum &= ~CSUM_DELAY_DATA;
}
m->m_pkthdr.csum_flags &= ifp->if_hwassist;
/*
* If small enough for interface, or the interface will take
* care of the fragmentation for us, can just send directly.
*/
if ((u_short)ip->ip_len <= ifp->if_mtu ||
ifp->if_hwassist & CSUM_FRAGMENT) {
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
ip->ip_sum = 0;
if (sw_csum & CSUM_DELAY_IP) {
if (ip->ip_vhl == IP_VHL_BORING) {
ip->ip_sum = in_cksum_hdr(ip);
} else {
ip->ip_sum = in_cksum(m, hlen);
}
}
/* Record statistics for this interface address. */
if (!(flags & IP_FORWARDING) && ia) {
ia->ia_ifa.if_opackets++;
ia->ia_ifa.if_obytes += m->m_pkthdr.len;
}
#ifdef IPSEC
/* clean ipsec history once it goes out of the node */
ipsec_delaux(m);
#endif
error = (*ifp->if_output)(ifp, m,
(struct sockaddr *)dst, ro->ro_rt);
goto done;
}
/*
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
*/
if (ip->ip_off & IP_DF) {
error = EMSGSIZE;
/*
* This case can happen if the user changed the MTU
* of an interface after enabling IP on it. Because
* most netifs don't keep track of routes pointing to
* them, there is no way for one to update all its
* routes when the MTU is changed.
*/
if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST))
&& !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU)
&& (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
}
ipstat.ips_cantfrag++;
goto bad;
}
len = (ifp->if_mtu - hlen) &~ 7;
if (len < 8) {
error = EMSGSIZE;
goto bad;
}
/*
* if the interface will not calculate checksums on
* fragmented packets, then do it here.
*/
if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA &&
(ifp->if_hwassist & CSUM_IP_FRAGS) == 0) {
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
if (len > PAGE_SIZE) {
/*
* Fragement large datagrams such that each segment
* contains a multiple of PAGE_SIZE amount of data,
* plus headers. This enables a receiver to perform
* page-flipping zero-copy optimizations.
*/
int newlen;
struct mbuf *mtmp;
for (mtmp = m, off = 0;
mtmp && ((off + mtmp->m_len) <= ifp->if_mtu);
mtmp = mtmp->m_next) {
off += mtmp->m_len;
}
/*
* firstlen (off - hlen) must be aligned on an
* 8-byte boundary
*/
if (off < hlen)
goto smart_frag_failure;
off = ((off - hlen) & ~7) + hlen;
newlen = (~PAGE_MASK) & ifp->if_mtu;
if ((newlen + sizeof (struct ip)) > ifp->if_mtu) {
/* we failed, go back the default */
smart_frag_failure:
newlen = len;
off = hlen + len;
}
/* printf("ipfrag: len = %d, hlen = %d, mhlen = %d, newlen = %d, off = %d\n",
len, hlen, sizeof (struct ip), newlen, off);*/
len = newlen;
} else {
off = hlen + len;
}
{
int mhlen, firstlen = off - hlen;
struct mbuf **mnext = &m->m_nextpkt;
int nfrags = 1;
/*
* Loop through length of segment after first fragment,
* make new header and copy data of each part and link onto chain.
*/
m0 = m;
mhlen = sizeof (struct ip);
for (; off < (u_short)ip->ip_len; off += len) {
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == 0) {
error = ENOBUFS;
ipstat.ips_odropped++;
goto sendorfree;
}
m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
m->m_data += max_linkhdr;
mhip = mtod(m, struct ip *);
*mhip = *ip;
if (hlen > sizeof (struct ip)) {
mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
}
m->m_len = mhlen;
mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
if (off + len >= (u_short)ip->ip_len)
len = (u_short)ip->ip_len - off;
else
mhip->ip_off |= IP_MF;
mhip->ip_len = htons((u_short)(len + mhlen));
m->m_next = m_copy(m0, off, len);
if (m->m_next == 0) {
(void) m_free(m);
error = ENOBUFS; /* ??? */
ipstat.ips_odropped++;
goto sendorfree;
}
m->m_pkthdr.len = mhlen + len;
m->m_pkthdr.rcvif = (struct ifnet *)0;
#ifdef MAC
mac_create_fragment(m0, m);
#endif
m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
mhip->ip_off = htons(mhip->ip_off);
mhip->ip_sum = 0;
if (sw_csum & CSUM_DELAY_IP) {
if (mhip->ip_vhl == IP_VHL_BORING) {
mhip->ip_sum = in_cksum_hdr(mhip);
} else {
mhip->ip_sum = in_cksum(m, mhlen);
}
}
*mnext = m;
mnext = &m->m_nextpkt;
nfrags++;
}
ipstat.ips_ofragments += nfrags;
/* set first/last markers for fragment chain */
m->m_flags |= M_LASTFRAG;
m0->m_flags |= M_FIRSTFRAG | M_FRAG;
m0->m_pkthdr.csum_data = nfrags;
/*
* Update first fragment by trimming what's been copied out
* and updating header, then send each fragment (in order).
*/
m = m0;
m_adj(m, hlen + firstlen - (u_short)ip->ip_len);
m->m_pkthdr.len = hlen + firstlen;
ip->ip_len = htons((u_short)m->m_pkthdr.len);
ip->ip_off |= IP_MF;
ip->ip_off = htons(ip->ip_off);
ip->ip_sum = 0;
if (sw_csum & CSUM_DELAY_IP) {
if (ip->ip_vhl == IP_VHL_BORING) {
ip->ip_sum = in_cksum_hdr(ip);
} else {
ip->ip_sum = in_cksum(m, hlen);
}
}
sendorfree:
for (m = m0; m; m = m0) {
m0 = m->m_nextpkt;
m->m_nextpkt = 0;
#ifdef IPSEC
/* clean ipsec history once it goes out of the node */
ipsec_delaux(m);
#endif
if (error == 0) {
/* Record statistics for this interface address. */
if (ia != NULL) {
ia->ia_ifa.if_opackets++;
ia->ia_ifa.if_obytes += m->m_pkthdr.len;
}
error = (*ifp->if_output)(ifp, m,
(struct sockaddr *)dst, ro->ro_rt);
} else
m_freem(m);
}
if (error == 0)
ipstat.ips_fragmented++;
}
done:
#ifdef IPSEC
if (ro == &iproute && ro->ro_rt) {
RTFREE(ro->ro_rt);
ro->ro_rt = NULL;
}
if (sp != NULL) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ip_output call free SP:%p\n", sp));
key_freesp(sp);
}
#endif /* IPSEC */
return (error);
bad:
m_freem(m);
goto done;
}
void
in_delayed_cksum(struct mbuf *m)
{
struct ip *ip;
u_short csum, offset;
ip = mtod(m, struct ip *);
offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
csum = in_cksum_skip(m, ip->ip_len, offset);
if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
csum = 0xffff;
offset += m->m_pkthdr.csum_data; /* checksum offset */
if (offset + sizeof(u_short) > m->m_len) {
printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
m->m_len, offset, ip->ip_p);
/*
* XXX
* this shouldn't happen, but if it does, the
* correct behavior may be to insert the checksum
* in the existing chain instead of rearranging it.
*/
m = m_pullup(m, offset + sizeof(u_short));
}
*(u_short *)(m->m_data + offset) = csum;
}
/*
* Insert IP options into preformed packet.
* Adjust IP destination as required for IP source routing,
* as indicated by a non-zero in_addr at the start of the options.
*
* XXX This routine assumes that the packet has no options in place.
*/
static struct mbuf *
ip_insertoptions(m, opt, phlen)
register struct mbuf *m;
struct mbuf *opt;
int *phlen;
{
register struct ipoption *p = mtod(opt, struct ipoption *);
struct mbuf *n;
register struct ip *ip = mtod(m, struct ip *);
unsigned optlen;
optlen = opt->m_len - sizeof(p->ipopt_dst);
if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
*phlen = 0;
return (m); /* XXX should fail */
}
if (p->ipopt_dst.s_addr)
ip->ip_dst = p->ipopt_dst;
if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
MGETHDR(n, M_DONTWAIT, MT_HEADER);
if (n == 0) {
*phlen = 0;
return (m);
}
n->m_pkthdr.rcvif = (struct ifnet *)0;
#ifdef MAC
mac_create_mbuf_from_mbuf(m, n);
#endif
n->m_pkthdr.len = m->m_pkthdr.len + optlen;
m->m_len -= sizeof(struct ip);
m->m_data += sizeof(struct ip);
n->m_next = m;
m = n;
m->m_len = optlen + sizeof(struct ip);
m->m_data += max_linkhdr;
(void)memcpy(mtod(m, void *), ip, sizeof(struct ip));
} else {
m->m_data -= optlen;
m->m_len += optlen;
m->m_pkthdr.len += optlen;
ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
}
ip = mtod(m, struct ip *);
bcopy(p->ipopt_list, ip + 1, optlen);
*phlen = sizeof(struct ip) + optlen;
ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
ip->ip_len += optlen;
return (m);
}
/*
* Copy options from ip to jp,
* omitting those not copied during fragmentation.
*/
int
ip_optcopy(ip, jp)
struct ip *ip, *jp;
{
register u_char *cp, *dp;
int opt, optlen, cnt;
cp = (u_char *)(ip + 1);
dp = (u_char *)(jp + 1);
cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[0];
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP) {
/* Preserve for IP mcast tunnel's LSRR alignment. */
*dp++ = IPOPT_NOP;
optlen = 1;
continue;
}
KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp),
("ip_optcopy: malformed ipv4 option"));
optlen = cp[IPOPT_OLEN];
KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt,
("ip_optcopy: malformed ipv4 option"));
/* bogus lengths should have been caught by ip_dooptions */
if (optlen > cnt)
optlen = cnt;
if (IPOPT_COPIED(opt)) {
bcopy(cp, dp, optlen);
dp += optlen;
}
}
for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
*dp++ = IPOPT_EOL;
return (optlen);
}
/*
* IP socket option processing.
*/
int
ip_ctloutput(so, sopt)
struct socket *so;
struct sockopt *sopt;
{
struct inpcb *inp = sotoinpcb(so);
int error, optval;
error = optval = 0;
if (sopt->sopt_level != IPPROTO_IP) {
return (EINVAL);
}
switch (sopt->sopt_dir) {
case SOPT_SET:
switch (sopt->sopt_name) {
case IP_OPTIONS:
#ifdef notyet
case IP_RETOPTS:
#endif
{
struct mbuf *m;
if (sopt->sopt_valsize > MLEN) {
error = EMSGSIZE;
break;
}
MGET(m, sopt->sopt_td ? M_TRYWAIT : M_DONTWAIT, MT_HEADER);
if (m == 0) {
error = ENOBUFS;
break;
}
m->m_len = sopt->sopt_valsize;
error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
m->m_len);
return (ip_pcbopts(sopt->sopt_name, &inp->inp_options,
m));
}
case IP_TOS:
case IP_TTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
case IP_RECVIF:
case IP_FAITH:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
break;
switch (sopt->sopt_name) {
case IP_TOS:
inp->inp_ip_tos = optval;
break;
case IP_TTL:
inp->inp_ip_ttl = optval;
break;
#define OPTSET(bit) \
if (optval) \
inp->inp_flags |= bit; \
else \
inp->inp_flags &= ~bit;
case IP_RECVOPTS:
OPTSET(INP_RECVOPTS);
break;
case IP_RECVRETOPTS:
OPTSET(INP_RECVRETOPTS);
break;
case IP_RECVDSTADDR:
OPTSET(INP_RECVDSTADDR);
break;
case IP_RECVIF:
OPTSET(INP_RECVIF);
break;
case IP_FAITH:
OPTSET(INP_FAITH);
break;
}
break;
#undef OPTSET
case IP_MULTICAST_IF:
case IP_MULTICAST_VIF:
case IP_MULTICAST_TTL:
case IP_MULTICAST_LOOP:
case IP_ADD_MEMBERSHIP:
case IP_DROP_MEMBERSHIP:
error = ip_setmoptions(sopt, &inp->inp_moptions);
break;
case IP_PORTRANGE:
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
break;
switch (optval) {
case IP_PORTRANGE_DEFAULT:
inp->inp_flags &= ~(INP_LOWPORT);
inp->inp_flags &= ~(INP_HIGHPORT);
break;
case IP_PORTRANGE_HIGH:
inp->inp_flags &= ~(INP_LOWPORT);
inp->inp_flags |= INP_HIGHPORT;
break;
case IP_PORTRANGE_LOW:
inp->inp_flags &= ~(INP_HIGHPORT);
inp->inp_flags |= INP_LOWPORT;
break;
default:
error = EINVAL;
break;
}
break;
#ifdef IPSEC
case IP_IPSEC_POLICY:
{
caddr_t req;
size_t len = 0;
int priv;
struct mbuf *m;
int optname;
if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
break;
if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
break;
priv = (sopt->sopt_td != NULL &&
suser(sopt->sopt_td) != 0) ? 0 : 1;
req = mtod(m, caddr_t);
len = m->m_len;
optname = sopt->sopt_name;
error = ipsec4_set_policy(inp, optname, req, len, priv);
m_freem(m);
break;
}
#endif /*IPSEC*/
default:
error = ENOPROTOOPT;
break;
}
break;
case SOPT_GET:
switch (sopt->sopt_name) {
case IP_OPTIONS:
case IP_RETOPTS:
if (inp->inp_options)
error = sooptcopyout(sopt,
mtod(inp->inp_options,
char *),
inp->inp_options->m_len);
else
sopt->sopt_valsize = 0;
break;
case IP_TOS:
case IP_TTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
case IP_RECVIF:
case IP_PORTRANGE:
case IP_FAITH:
switch (sopt->sopt_name) {
case IP_TOS:
optval = inp->inp_ip_tos;
break;
case IP_TTL:
optval = inp->inp_ip_ttl;
break;
#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
case IP_RECVOPTS:
optval = OPTBIT(INP_RECVOPTS);
break;
case IP_RECVRETOPTS:
optval = OPTBIT(INP_RECVRETOPTS);
break;
case IP_RECVDSTADDR:
optval = OPTBIT(INP_RECVDSTADDR);
break;
case IP_RECVIF:
optval = OPTBIT(INP_RECVIF);
break;
case IP_PORTRANGE:
if (inp->inp_flags & INP_HIGHPORT)
optval = IP_PORTRANGE_HIGH;
else if (inp->inp_flags & INP_LOWPORT)
optval = IP_PORTRANGE_LOW;
else
optval = 0;
break;
case IP_FAITH:
optval = OPTBIT(INP_FAITH);
break;
}
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case IP_MULTICAST_IF:
case IP_MULTICAST_VIF:
case IP_MULTICAST_TTL:
case IP_MULTICAST_LOOP:
case IP_ADD_MEMBERSHIP:
case IP_DROP_MEMBERSHIP:
error = ip_getmoptions(sopt, inp->inp_moptions);
break;
#ifdef IPSEC
case IP_IPSEC_POLICY:
{
struct mbuf *m = NULL;
caddr_t req = NULL;
size_t len = 0;
if (m != 0) {
req = mtod(m, caddr_t);
len = m->m_len;
}
error = ipsec4_get_policy(sotoinpcb(so), req, len, &m);
if (error == 0)
error = soopt_mcopyout(sopt, m); /* XXX */
if (error == 0)
m_freem(m);
break;
}
#endif /*IPSEC*/
default:
error = ENOPROTOOPT;
break;
}
break;
}
return (error);
}
/*
* Set up IP options in pcb for insertion in output packets.
* Store in mbuf with pointer in pcbopt, adding pseudo-option
* with destination address if source routed.
*/
static int
ip_pcbopts(optname, pcbopt, m)
int optname;
struct mbuf **pcbopt;
register struct mbuf *m;
{
register int cnt, optlen;
register u_char *cp;
u_char opt;
/* turn off any old options */
if (*pcbopt)
(void)m_free(*pcbopt);
*pcbopt = 0;
if (m == (struct mbuf *)0 || m->m_len == 0) {
/*
* Only turning off any previous options.
*/
if (m)
(void)m_free(m);
return (0);
}
if (m->m_len % sizeof(int32_t))
goto bad;
/*
* IP first-hop destination address will be stored before
* actual options; move other options back
* and clear it when none present.
*/
if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
goto bad;
cnt = m->m_len;
m->m_len += sizeof(struct in_addr);
cp = mtod(m, u_char *) + sizeof(struct in_addr);
ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt);
bzero(mtod(m, caddr_t), sizeof(struct in_addr));
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))
goto bad;
optlen = cp[IPOPT_OLEN];
if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt)
goto bad;
}
switch (opt) {
default:
break;
case IPOPT_LSRR:
case IPOPT_SSRR:
/*
* user process specifies route as:
* ->A->B->C->D
* D must be our final destination (but we can't
* check that since we may not have connected yet).
* A is first hop destination, which doesn't appear in
* actual IP option, but is stored before the options.
*/
if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
goto bad;
m->m_len -= sizeof(struct in_addr);
cnt -= sizeof(struct in_addr);
optlen -= sizeof(struct in_addr);
cp[IPOPT_OLEN] = optlen;
/*
* Move first hop before start of options.
*/
bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
sizeof(struct in_addr));
/*
* Then copy rest of options back
* to close up the deleted entry.
*/
ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] +
sizeof(struct in_addr)),
(caddr_t)&cp[IPOPT_OFFSET+1],
(unsigned)cnt + sizeof(struct in_addr));
break;
}
}
if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
goto bad;
*pcbopt = m;
return (0);
bad:
(void)m_free(m);
return (EINVAL);
}
/*
* XXX
* The whole multicast option thing needs to be re-thought.
* Several of these options are equally applicable to non-multicast
* transmission, and one (IP_MULTICAST_TTL) totally duplicates a
* standard option (IP_TTL).
*/
/*
* following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
*/
static struct ifnet *
ip_multicast_if(a, ifindexp)
struct in_addr *a;
int *ifindexp;
{
int ifindex;
struct ifnet *ifp;
if (ifindexp)
*ifindexp = 0;
if (ntohl(a->s_addr) >> 24 == 0) {
ifindex = ntohl(a->s_addr) & 0xffffff;
if (ifindex < 0 || if_index < ifindex)
return NULL;
ifp = ifnet_byindex(ifindex);
if (ifindexp)
*ifindexp = ifindex;
} else {
INADDR_TO_IFP(*a, ifp);
}
return ifp;
}
/*
* Set the IP multicast options in response to user setsockopt().
*/
static int
ip_setmoptions(sopt, imop)
struct sockopt *sopt;
struct ip_moptions **imop;
{
int error = 0;
int i;
struct in_addr addr;
struct ip_mreq mreq;
struct ifnet *ifp;
struct ip_moptions *imo = *imop;
struct route ro;
struct sockaddr_in *dst;
int ifindex;
int s;
if (imo == NULL) {
/*
* No multicast option buffer attached to the pcb;
* allocate one and initialize to default values.
*/
imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS,
M_WAITOK);
if (imo == NULL)
return (ENOBUFS);
*imop = imo;
imo->imo_multicast_ifp = NULL;
imo->imo_multicast_addr.s_addr = INADDR_ANY;
imo->imo_multicast_vif = -1;
imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
imo->imo_num_memberships = 0;
}
switch (sopt->sopt_name) {
/* store an index number for the vif you wanna use in the send */
case IP_MULTICAST_VIF:
if (legal_vif_num == 0) {
error = EOPNOTSUPP;
break;
}
error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
if (error)
break;
if (!legal_vif_num(i) && (i != -1)) {
error = EINVAL;
break;
}
imo->imo_multicast_vif = i;
break;
case IP_MULTICAST_IF:
/*
* Select the interface for outgoing multicast packets.
*/
error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
if (error)
break;
/*
* INADDR_ANY is used to remove a previous selection.
* When no interface is selected, a default one is
* chosen every time a multicast packet is sent.
*/
if (addr.s_addr == INADDR_ANY) {
imo->imo_multicast_ifp = NULL;
break;
}
/*
* The selected interface is identified by its local
* IP address. Find the interface and confirm that
* it supports multicasting.
*/
s = splimp();
ifp = ip_multicast_if(&addr, &ifindex);
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
splx(s);
error = EADDRNOTAVAIL;
break;
}
imo->imo_multicast_ifp = ifp;
if (ifindex)
imo->imo_multicast_addr = addr;
else
imo->imo_multicast_addr.s_addr = INADDR_ANY;
splx(s);
break;
case IP_MULTICAST_TTL:
/*
* Set the IP time-to-live for outgoing multicast packets.
* The original multicast API required a char argument,
* which is inconsistent with the rest of the socket API.
* We allow either a char or an int.
*/
if (sopt->sopt_valsize == 1) {
u_char ttl;
error = sooptcopyin(sopt, &ttl, 1, 1);
if (error)
break;
imo->imo_multicast_ttl = ttl;
} else {
u_int ttl;
error = sooptcopyin(sopt, &ttl, sizeof ttl,
sizeof ttl);
if (error)
break;
if (ttl > 255)
error = EINVAL;
else
imo->imo_multicast_ttl = ttl;
}
break;
case IP_MULTICAST_LOOP:
/*
* Set the loopback flag for outgoing multicast packets.
* Must be zero or one. The original multicast API required a
* char argument, which is inconsistent with the rest
* of the socket API. We allow either a char or an int.
*/
if (sopt->sopt_valsize == 1) {
u_char loop;
error = sooptcopyin(sopt, &loop, 1, 1);
if (error)
break;
imo->imo_multicast_loop = !!loop;
} else {
u_int loop;
error = sooptcopyin(sopt, &loop, sizeof loop,
sizeof loop);
if (error)
break;
imo->imo_multicast_loop = !!loop;
}
break;
case IP_ADD_MEMBERSHIP:
/*
* Add a multicast group membership.
* Group must be a valid IP multicast address.
*/
error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
if (error)
break;
if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
error = EINVAL;
break;
}
s = splimp();
/*
* If no interface address was provided, use the interface of
* the route to the given multicast address.
*/
if (mreq.imr_interface.s_addr == INADDR_ANY) {
bzero((caddr_t)&ro, sizeof(ro));
dst = (struct sockaddr_in *)&ro.ro_dst;
dst->sin_len = sizeof(*dst);
dst->sin_family = AF_INET;
dst->sin_addr = mreq.imr_multiaddr;
rtalloc(&ro);
if (ro.ro_rt == NULL) {
error = EADDRNOTAVAIL;
splx(s);
break;
}
ifp = ro.ro_rt->rt_ifp;
rtfree(ro.ro_rt);
}
else {
ifp = ip_multicast_if(&mreq.imr_interface, NULL);
}
/*
* See if we found an interface, and confirm that it
* supports multicast.
*/
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
error = EADDRNOTAVAIL;
splx(s);
break;
}
/*
* See if the membership already exists or if all the
* membership slots are full.
*/
for (i = 0; i < imo->imo_num_memberships; ++i) {
if (imo->imo_membership[i]->inm_ifp == ifp &&
imo->imo_membership[i]->inm_addr.s_addr
== mreq.imr_multiaddr.s_addr)
break;
}
if (i < imo->imo_num_memberships) {
error = EADDRINUSE;
splx(s);
break;
}
if (i == IP_MAX_MEMBERSHIPS) {
error = ETOOMANYREFS;
splx(s);
break;
}
/*
* Everything looks good; add a new record to the multicast
* address list for the given interface.
*/
if ((imo->imo_membership[i] =
in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
error = ENOBUFS;
splx(s);
break;
}
++imo->imo_num_memberships;
splx(s);
break;
case IP_DROP_MEMBERSHIP:
/*
* Drop a multicast group membership.
* Group must be a valid IP multicast address.
*/
error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
if (error)
break;
if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
error = EINVAL;
break;
}
s = splimp();
/*
* If an interface address was specified, get a pointer
* to its ifnet structure.
*/
if (mreq.imr_interface.s_addr == INADDR_ANY)
ifp = NULL;
else {
ifp = ip_multicast_if(&mreq.imr_interface, NULL);
if (ifp == NULL) {
error = EADDRNOTAVAIL;
splx(s);
break;
}
}
/*
* Find the membership in the membership array.
*/
for (i = 0; i < imo->imo_num_memberships; ++i) {
if ((ifp == NULL ||
imo->imo_membership[i]->inm_ifp == ifp) &&
imo->imo_membership[i]->inm_addr.s_addr ==
mreq.imr_multiaddr.s_addr)
break;
}
if (i == imo->imo_num_memberships) {
error = EADDRNOTAVAIL;
splx(s);
break;
}
/*
* Give up the multicast address record to which the
* membership points.
*/
in_delmulti(imo->imo_membership[i]);
/*
* Remove the gap in the membership array.
*/
for (++i; i < imo->imo_num_memberships; ++i)
imo->imo_membership[i-1] = imo->imo_membership[i];
--imo->imo_num_memberships;
splx(s);
break;
default:
error = EOPNOTSUPP;
break;
}
/*
* If all options have default values, no need to keep the mbuf.
*/
if (imo->imo_multicast_ifp == NULL &&
imo->imo_multicast_vif == -1 &&
imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
imo->imo_num_memberships == 0) {
free(*imop, M_IPMOPTS);
*imop = NULL;
}
return (error);
}
/*
* Return the IP multicast options in response to user getsockopt().
*/
static int
ip_getmoptions(sopt, imo)
struct sockopt *sopt;
register struct ip_moptions *imo;
{
struct in_addr addr;
struct in_ifaddr *ia;
int error, optval;
u_char coptval;
error = 0;
switch (sopt->sopt_name) {
case IP_MULTICAST_VIF:
if (imo != NULL)
optval = imo->imo_multicast_vif;
else
optval = -1;
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case IP_MULTICAST_IF:
if (imo == NULL || imo->imo_multicast_ifp == NULL)
addr.s_addr = INADDR_ANY;
else if (imo->imo_multicast_addr.s_addr) {
/* return the value user has set */
addr = imo->imo_multicast_addr;
} else {
IFP_TO_IA(imo->imo_multicast_ifp, ia);
addr.s_addr = (ia == NULL) ? INADDR_ANY
: IA_SIN(ia)->sin_addr.s_addr;
}
error = sooptcopyout(sopt, &addr, sizeof addr);
break;
case IP_MULTICAST_TTL:
if (imo == 0)
optval = coptval = IP_DEFAULT_MULTICAST_TTL;
else
optval = coptval = imo->imo_multicast_ttl;
if (sopt->sopt_valsize == 1)
error = sooptcopyout(sopt, &coptval, 1);
else
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case IP_MULTICAST_LOOP:
if (imo == 0)
optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
else
optval = coptval = imo->imo_multicast_loop;
if (sopt->sopt_valsize == 1)
error = sooptcopyout(sopt, &coptval, 1);
else
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
default:
error = ENOPROTOOPT;
break;
}
return (error);
}
/*
* Discard the IP multicast options.
*/
void
ip_freemoptions(imo)
register struct ip_moptions *imo;
{
register int i;
if (imo != NULL) {
for (i = 0; i < imo->imo_num_memberships; ++i)
in_delmulti(imo->imo_membership[i]);
free(imo, M_IPMOPTS);
}
}
/*
* Routine called from ip_output() to loop back a copy of an IP multicast
* packet to the input queue of a specified interface. Note that this
* calls the output routine of the loopback "driver", but with an interface
* pointer that might NOT be a loopback interface -- evil, but easier than
* replicating that code here.
*/
static void
ip_mloopback(ifp, m, dst, hlen)
struct ifnet *ifp;
register struct mbuf *m;
register struct sockaddr_in *dst;
int hlen;
{
register struct ip *ip;
struct mbuf *copym;
copym = m_copy(m, 0, M_COPYALL);
if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
copym = m_pullup(copym, hlen);
if (copym != NULL) {
/*
* We don't bother to fragment if the IP length is greater
* than the interface's MTU. Can this possibly matter?
*/
ip = mtod(copym, struct ip *);
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
ip->ip_sum = 0;
if (ip->ip_vhl == IP_VHL_BORING) {
ip->ip_sum = in_cksum_hdr(ip);
} else {
ip->ip_sum = in_cksum(copym, hlen);
}
/*
* NB:
* It's not clear whether there are any lingering
* reentrancy problems in other areas which might
* be exposed by using ip_input directly (in
* particular, everything which modifies the packet
* in-place). Yet another option is using the
* protosw directly to deliver the looped back
* packet. For the moment, we'll err on the side
* of safety by using if_simloop().
*/
#if 1 /* XXX */
if (dst->sin_family != AF_INET) {
printf("ip_mloopback: bad address family %d\n",
dst->sin_family);
dst->sin_family = AF_INET;
}
#endif
#ifdef notdef
copym->m_pkthdr.rcvif = ifp;
ip_input(copym);
#else
/* if the checksum hasn't been computed, mark it as valid */
if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
copym->m_pkthdr.csum_flags |=
CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
copym->m_pkthdr.csum_data = 0xffff;
}
if_simloop(ifp, copym, dst->sin_family, 0);
#endif
}
}
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