NetBSD/sys/netinet6/ipcomp_output.c

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/* $NetBSD: ipcomp_output.c,v 1.7 2000/01/06 15:46:10 itojun Exp $ */
1999-07-04 01:24:45 +04:00
/*
* Copyright (C) 1999 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* RFC2393 IP payload compression protocol (IPComp).
*/
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/zlib.h>
#include <machine/cpu.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_ecn.h>
#ifdef INET6
#include <netinet6/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#endif
#include <netinet6/ipcomp.h>
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#include <netkey/keydb.h>
#include <netkey/key_debug.h>
#include <machine/stdarg.h>
#ifdef __NetBSD__
#define ovbcopy bcopy
#endif
static int ipcomp_output __P((struct mbuf *, u_char *, struct mbuf *,
struct ipsecrequest *, int));
/*
* Modify the packet so that the payload is compressed.
* The mbuf (m) must start with IPv4 or IPv6 header.
* On failure, free the given mbuf and return NULL.
*
* on invocation:
* m nexthdrp md
* v v v
* IP ......... payload
* during the encryption:
* m nexthdrp mprev md
* v v v v
* IP ............... ipcomp payload
* <-----><----->
* complen plen
* <-> hlen
* <-----------------> compoff
*/
static int
ipcomp_output(m, nexthdrp, md, isr, af)
struct mbuf *m;
u_char *nexthdrp;
struct mbuf *md;
struct ipsecrequest *isr;
int af;
{
struct mbuf *n;
struct mbuf *md0;
struct mbuf *mprev;
struct ipcomp *ipcomp;
struct secas *sa = isr->sa;
struct ipcomp_algorithm *algo;
u_int16_t cpi; /* host order */
size_t plen0, plen; /*payload length to be compressed*/
size_t compoff;
int afnumber;
int error = 0;
switch (af) {
#ifdef INET
case AF_INET:
afnumber = 4;
break;
#endif
#ifdef INET6
case AF_INET6:
afnumber = 6;
break;
#endif
default:
printf("ipcomp_output: unsupported af %d\n", af);
return 0; /* no change at all */
}
/* grab parameters */
if ((ntohl(sa->spi) & ~0xffff) != 0 || sa->alg_enc >= IPCOMP_MAX
|| ipcomp_algorithms[sa->alg_enc].compress == NULL) {
ipsecstat.out_inval++;
m_freem(m);
return EINVAL;
}
if ((sa->flags & SADB_X_EXT_RAWCPI) == 0)
cpi = sa->alg_enc;
else
cpi = ntohl(sa->spi) & 0xffff;
algo = &ipcomp_algorithms[sa->alg_enc]; /*XXX*/
/* compute original payload length */
plen = 0;
for (n = md; n; n = n->m_next)
plen += n->m_len;
/* if the payload is short enough, we don't need to compress */
if (plen < algo->minplen)
return 0;
/*
* keep the original data packet, so that we can backout
* our changes when compression is not necessary.
*/
md0 = m_copym(md, 0, M_COPYALL, M_NOWAIT);
if (md0 == NULL) {
error = ENOBUFS;
return 0;
}
plen0 = plen;
/* make the packet over-writable */
for (mprev = m; mprev && mprev->m_next != md; mprev = mprev->m_next)
;
if (mprev == NULL || mprev->m_next != md) {
printf("ipcomp%d_output: md is not in chain\n", afnumber);
m_freem(m);
m_freem(md0);
return EINVAL;
}
mprev->m_next = NULL;
if ((md = ipsec_copypkt(md)) == NULL) {
m_freem(m);
m_freem(md0);
error = ENOBUFS;
goto fail;
}
mprev->m_next = md;
/* compress data part */
if ((*algo->compress)(m, md, &plen) || mprev->m_next == NULL) {
printf("packet compression failure\n");
m = NULL;
m_freem(md0);
switch (af) {
#ifdef INET
case AF_INET:
ipsecstat.out_inval++;
break;
#endif
#ifdef INET6
case AF_INET6:
ipsec6stat.out_inval++;
break;
#endif
}
error = EINVAL;
goto fail;
}
md = mprev->m_next;
/*
* if the packet became bigger, meaningless to use IPComp.
* we've only wasted our cpu time.
*/
if (plen0 < plen) {
m_freem(md);
mprev->m_next = md0;
return 0;
}
/* no need to backout change beyond here */
m_freem(md0);
md0 = NULL;
m->m_pkthdr.len -= plen0;
m->m_pkthdr.len += plen;
{
/*
* insert IPComp header.
*/
#ifdef INET
struct ip *ip = NULL;
#endif
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
#endif
size_t hlen = 0; /*ip header len*/
size_t complen = sizeof(struct ipcomp);
switch (af) {
#ifdef INET
case AF_INET:
ip = mtod(m, struct ip *);
#ifdef _IP_VHL
hlen = IP_VHL_HL(ip->ip_vhl) << 2;
#else
hlen = ip->ip_hl << 2;
#endif
break;
#endif
#ifdef INET6
case AF_INET6:
ip6 = mtod(m, struct ip6_hdr *);
hlen = sizeof(*ip6);
break;
#endif
}
compoff = m->m_pkthdr.len - plen;
/*
* grow the mbuf to accomodate ipcomp header.
* before: IP ... payload
* after: IP ... ipcomp payload
*/
if (M_LEADINGSPACE(md) < complen) {
MGET(n, M_DONTWAIT, MT_DATA);
if (!n) {
m_freem(m);
error = ENOBUFS;
goto fail;
}
n->m_len = complen;
mprev->m_next = n;
n->m_next = md;
m->m_pkthdr.len += complen;
ipcomp = mtod(n, struct ipcomp *);
} else {
md->m_len += complen;
md->m_data -= complen;
m->m_pkthdr.len += complen;
ipcomp = mtod(md, struct ipcomp *);
}
bzero(ipcomp, sizeof(*ipcomp));
ipcomp->comp_nxt = *nexthdrp;
*nexthdrp = IPPROTO_IPCOMP;
ipcomp->comp_cpi = htons(cpi);
switch (af) {
#ifdef INET
case AF_INET:
if (compoff + complen + plen < IP_MAXPACKET)
ip->ip_len = htons(compoff + complen + plen);
else {
printf("IPv4 ESP output: size exceeds limit\n");
ipsecstat.out_inval++;
m_freem(m);
error = EMSGSIZE;
goto fail;
}
break;
#endif
#ifdef INET6
case AF_INET6:
/* total packet length will be computed in ip6_output() */
break;
#endif
}
}
if (!m) {
printf("NULL mbuf after compression in ipcomp%d_output",
afnumber);
} else {
switch (af) {
#ifdef INET
case AF_INET:
ipsecstat.out_success++;
break;
#endif
#ifdef INET6
case AF_INET6:
ipsec6stat.out_success++;
break;
#endif
}
}
#if 0
switch (af) {
#ifdef INET
case AF_INET:
ipsecstat.out_esphist[sa->alg_enc]++;
break;
#endif
#ifdef INET6
case AF_INET6:
ipsec6stat.out_esphist[sa->alg_enc]++;
break;
#endif
}
#endif
key_sa_recordxfer(sa, m);
return 0;
fail:
#if 1
return error;
#else
panic("something bad in ipcomp_output");
#endif
}
#ifdef INET
int
ipcomp4_output(m, isr)
struct mbuf *m;
struct ipsecrequest *isr;
{
struct ip *ip;
if (m->m_len < sizeof(struct ip)) {
printf("ipcomp4_output: first mbuf too short\n");
m_freem(m);
return NULL;
}
ip = mtod(m, struct ip *);
/* XXX assumes that m->m_next points to payload */
return ipcomp_output(m, &ip->ip_p, m->m_next, isr, AF_INET);
}
#endif /*INET*/
#ifdef INET6
int
ipcomp6_output(m, nexthdrp, md, isr)
struct mbuf *m;
u_char *nexthdrp;
struct mbuf *md;
struct ipsecrequest *isr;
{
if (m->m_len < sizeof(struct ip6_hdr)) {
printf("ipcomp6_output: first mbuf too short\n");
m_freem(m);
return NULL;
}
return ipcomp_output(m, nexthdrp, md, isr, AF_INET6);
}
#endif /*INET6*/