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freebsd-dev/sys/netinet/ip_output.c
Archie Cobbs 8948e4ba8e Miscellaneous fixes/cleanups relating to ipfw and divert(4): 
- Implement 'ipfw tee' (finally)
- Divert packets by calling new function divert_packet() directly instead
  of going through protosw[].
- Replace kludgey global variable 'ip_divert_port' with a function parameter
  to divert_packet()
- Replace kludgey global variable 'frag_divert_port' with a function parameter
  to ip_reass()
- style(9) fixes

Reviewed by:	julian, green
1999-12-06 00:43:07 +00:00

1572 lines
40 KiB
C
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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 <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.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>
#ifdef vax
#include <machine/mtpr.h>
#endif
#include <machine/in_cksum.h>
static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
#include <netinet/ip_fw.h>
#ifdef DUMMYNET
#include <netinet/ip_dummynet.h>
#endif
#ifdef IPFIREWALL_FORWARD_DEBUG
#define print_ip(a) printf("%ld.%ld.%ld.%ld",(ntohl(a.s_addr)>>24)&0xFF,\
(ntohl(a.s_addr)>>16)&0xFF,\
(ntohl(a.s_addr)>>8)&0xFF,\
(ntohl(a.s_addr))&0xFF);
#endif
u_short ip_id;
static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *));
static void ip_mloopback
__P((struct ifnet *, struct mbuf *, struct sockaddr_in *, int));
static int ip_getmoptions
__P((struct sockopt *, struct ip_moptions *));
static int ip_pcbopts __P((int, struct mbuf **, struct mbuf *));
static int ip_setmoptions
__P((struct sockopt *, struct ip_moptions **));
#if defined(IPFILTER_LKM) || defined(IPFILTER)
int ip_optcopy __P((struct ip *, struct ip *));
extern int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int, struct mbuf **));
#else
static int ip_optcopy __P((struct ip *, struct ip *));
#endif
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;
struct mbuf *m = m0;
int hlen = sizeof (struct ip);
int len, off, error = 0;
struct sockaddr_in *dst;
struct in_ifaddr *ia;
int isbroadcast;
u_int16_t divert_cookie; /* firewall cookie */
#ifdef IPFIREWALL_FORWARD
int fwd_rewrite_src = 0;
#endif
struct ip_fw_chain *rule = NULL;
#ifdef IPDIVERT
/* Get and reset firewall cookie */
divert_cookie = ip_divert_cookie;
ip_divert_cookie = 0;
#else
divert_cookie = 0;
#endif
#if defined(IPFIREWALL) && defined(DUMMYNET)
/*
* dummynet packet are prepended a vestigial mbuf with
* m_type = MT_DUMMYNET and m_data pointing to the matching
* rule.
*/
if (m->m_type == MT_DUMMYNET) {
/*
* the packet was already tagged, so part of the
* processing was already done, and we need to go down.
* opt, flags and imo have already been used, and now
* they are used to hold ifp, dst and NULL, respectively.
*/
rule = (struct ip_fw_chain *)(m->m_data) ;
m0 = m = m->m_next ;
ip = mtod(m, struct ip *);
dst = (struct sockaddr_in *)flags ;
ifp = (struct ifnet *)opt;
hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
opt = NULL ;
flags = 0 ; /* XXX is this correct ? */
goto sendit;
} else
rule = NULL ;
#endif
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ip_output no HDR");
if (!ro)
panic("ip_output no route, proto = %d",
mtod(m, struct ip *)->ip_p);
#endif
if (opt) {
m = ip_insertoptions(m, opt, &len);
hlen = len;
}
ip = mtod(m, struct ip *);
/*
* 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;
ip->ip_id = htons(ip_id++);
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.
*/
if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
RTFREE(ro->ro_rt);
ro->ro_rt = (struct rtentry *)0;
}
if (ro->ro_rt == 0) {
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = ip->ip_dst;
}
/*
* If routing to interface only,
* short circuit routing lookup.
*/
#define ifatoia(ifa) ((struct in_ifaddr *)(ifa))
#define sintosa(sin) ((struct sockaddr *)(sin))
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 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(ip->ip_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_ifp != NULL)
ifp = imo->imo_multicast_ifp;
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) {
register struct in_ifaddr *ia1;
for (ia1 = in_ifaddrhead.tqh_first; ia1;
ia1 = ia1->ia_link.tqe_next)
if (ia1->ia_ifp == ifp) {
ip->ip_src = IA_SIN(ia1)->sin_addr;
break;
}
}
IN_LOOKUP_MULTI(ip->ip_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 source address not specified yet, use address
* of outgoing interface.
*/
if (ip->ip_src.s_addr == INADDR_ANY) {
ip->ip_src = IA_SIN(ia)->sin_addr;
#ifdef IPFIREWALL_FORWARD
/* Keep note that we did this - if the firewall changes
* the next-hop, our interface may change, changing the
* default source IP. It's a shame so much effort happens
* twice. Oh well.
*/
fwd_rewrite_src++;
#endif /* IPFIREWALL_FORWARD */
}
#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;
goto bad;
}
/*
* Look for broadcast address and
* 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:
/*
* 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.>
*/
#if defined(IPFILTER) || defined(IPFILTER_LKM)
if (fr_checkp) {
struct mbuf *m1 = m;
if ((error = (*fr_checkp)(ip, hlen, ifp, 1, &m1)) || !m1)
goto done;
ip = mtod(m = m1, struct ip *);
}
#endif
/*
* Check with the firewall...
*/
if (ip_fw_chk_ptr) {
struct sockaddr_in *old = dst;
off = (*ip_fw_chk_ptr)(&ip,
hlen, ifp, &divert_cookie, &m, &rule, &dst);
/*
* On return we must do the following:
* m == NULL -> drop the pkt
* 1<=off<= 0xffff -> DIVERT
* (off & 0x10000) -> send to a DUMMYNET pipe
* (off & 0x20000) -> TEE the packet
* dst != old -> IPFIREWALL_FORWARD
* off==0, dst==old -> accept
* If some of the above modules is 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 (!m) { /* firewall said to reject */
error = EACCES;
goto done;
}
if (off == 0 && dst == old) /* common case */
goto pass ;
#ifdef DUMMYNET
if ((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!
*/
dummynet_io(off & 0xffff, DN_TO_IP_OUT, m,ifp,ro,dst,rule);
goto done;
}
#endif
#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);
/* Restore packet header fields to original values */
HTONS(ip->ip_len);
HTONS(ip->ip_off);
/* Deliver packet to divert input routine */
ip_divert_cookie = divert_cookie;
divert_packet(m, 0, off & 0xffff);
/* If 'tee', continue with original packet */
if (clone != NULL) {
m = clone;
ip = mtod(m, struct ip *);
goto pass;
}
goto done;
}
#endif
#ifdef IPFIREWALL_FORWARD
/* Here we check dst to make sure it's 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) {
struct in_ifaddr *ia;
/* It's changed... */
/* There must be a better way to do this next line... */
static struct route sro_fwd, *ro_fwd = &sro_fwd;
#ifdef IPFIREWALL_FORWARD_DEBUG
printf("IPFIREWALL_FORWARD: New dst ip: ");
print_ip(dst->sin_addr);
printf("\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.
*/
for (ia = TAILQ_FIRST(&in_ifaddrhead); ia;
ia = TAILQ_NEXT(ia, ia_link)) {
/*
* 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" */
ip_fw_fwd_addr = dst;
if (m->m_pkthdr.rcvif == NULL)
m->m_pkthdr.rcvif = ifunit("lo0");
ip->ip_len = htons((u_short)ip->ip_len);
ip->ip_off = htons((u_short)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(m, hlen);
}
ip_input(m);
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);
RTFREE(ro->ro_rt);
ro->ro_rt = ro_fwd->ro_rt;
dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
/*
* 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 (fwd_rewrite_src)
ip->ip_src = IA_SIN(ia)->sin_addr;
goto pass ;
}
#endif /* IPFIREWALL_FORWARD */
/*
* 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:
/*
* If small enough for interface, can just send directly.
*/
if ((u_short)ip->ip_len <= ifp->if_mtu) {
ip->ip_len = htons((u_short)ip->ip_len);
ip->ip_off = htons((u_short)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(m, hlen);
}
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;
}
{
int mhlen, firstlen = len;
struct mbuf **mnext = &m->m_nextpkt;
/*
* 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 = hlen + len; 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->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 & ~IP_MF);
if (ip->ip_off & IP_MF)
mhip->ip_off |= IP_MF;
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;
mhip->ip_off = htons((u_short)mhip->ip_off);
mhip->ip_sum = 0;
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;
ipstat.ips_ofragments++;
}
/*
* 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 = htons((u_short)(ip->ip_off | IP_MF));
ip->ip_sum = 0;
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;
if (error == 0)
error = (*ifp->if_output)(ifp, m,
(struct sockaddr *)dst, ro->ro_rt);
else
m_freem(m);
}
if (error == 0)
ipstat.ips_fragmented++;
}
done:
return (error);
bad:
m_freem(m0);
goto done;
}
/*
* 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)
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)
return (m);
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.
*/
#if !defined(IPFILTER) && !defined(IPFILTER_LKM)
static
#endif
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;
} else
optlen = cp[IPOPT_OLEN];
/* 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_p ? M_WAIT : 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:
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;
}
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;
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:
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;
}
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;
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);
}
#ifndef vax
if (m->m_len % sizeof(int32_t))
goto bad;
#endif
/*
* 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 {
optlen = cp[IPOPT_OLEN];
if (optlen <= IPOPT_OLEN || 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).
*/
/*
* 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 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_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();
INADDR_TO_IFP(addr, ifp);
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
splx(s);
error = EADDRNOTAVAIL;
break;
}
imo->imo_multicast_ifp = ifp;
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 {
INADDR_TO_IFP(mreq.imr_interface, ifp);
}
/*
* 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 {
INADDR_TO_IFP(mreq.imr_interface, ifp);
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 {
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((u_short)ip->ip_len);
ip->ip_off = htons((u_short)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_simloop(ifp, copym, (struct sockaddr *)dst, 0);
#endif
}
}
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