526 lines
14 KiB
C
526 lines
14 KiB
C
/*
|
|
* Copyright (c) 1982, 1986, 1989 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.
|
|
*
|
|
* from: @(#)ip_icmp.c 7.15 (Berkeley) 4/20/91
|
|
* $Id: ip_icmp.c,v 1.3 1993/12/06 04:59:34 hpeyerl Exp $
|
|
*/
|
|
|
|
#include "param.h"
|
|
#include "systm.h"
|
|
#include "malloc.h"
|
|
#include "mbuf.h"
|
|
#include "protosw.h"
|
|
#include "socket.h"
|
|
#include "time.h"
|
|
#include "kernel.h"
|
|
|
|
#include "../net/route.h"
|
|
#include "../net/if.h"
|
|
|
|
#include "in.h"
|
|
#include "in_systm.h"
|
|
#include "in_var.h"
|
|
#include "ip.h"
|
|
#include "ip_icmp.h"
|
|
#include "icmp_var.h"
|
|
|
|
/*
|
|
* ICMP routines: error generation, receive packet processing, and
|
|
* routines to turnaround packets back to the originator, and
|
|
* host table maintenance routines.
|
|
*/
|
|
#ifdef ICMPPRINTFS
|
|
int icmpprintfs = 0;
|
|
#endif
|
|
|
|
extern struct protosw inetsw[];
|
|
|
|
/*
|
|
* Generate an error packet of type error
|
|
* in response to bad packet ip.
|
|
*/
|
|
/*VARARGS3*/
|
|
icmp_error(n, type, code, dest)
|
|
struct mbuf *n;
|
|
int type, code;
|
|
struct in_addr dest;
|
|
{
|
|
register struct ip *oip = mtod(n, struct ip *), *nip;
|
|
register unsigned oiplen = oip->ip_hl << 2;
|
|
register struct icmp *icp;
|
|
register struct mbuf *m;
|
|
unsigned icmplen;
|
|
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_error(%x, %d, %d)\n", oip, type, code);
|
|
#endif
|
|
if (type != ICMP_REDIRECT)
|
|
icmpstat.icps_error++;
|
|
/*
|
|
* Don't send error if not the first fragment of message.
|
|
* Don't error if the old packet protocol was ICMP
|
|
* error message, only known informational types.
|
|
*/
|
|
if (oip->ip_off &~ (IP_MF|IP_DF))
|
|
goto freeit;
|
|
if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
|
|
n->m_len >= oiplen + ICMP_MINLEN &&
|
|
!ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
|
|
icmpstat.icps_oldicmp++;
|
|
goto freeit;
|
|
}
|
|
#ifdef MULTICAST
|
|
/* Don't send error in response to a multicast or broadcast packet */
|
|
if (n->m_flags & (M_MCAST | M_BCAST))
|
|
goto freeit;
|
|
#endif
|
|
/*
|
|
* First, formulate icmp message
|
|
*/
|
|
m = m_gethdr(M_DONTWAIT, MT_HEADER);
|
|
if (m == NULL)
|
|
goto freeit;
|
|
icmplen = oiplen + min(8, oip->ip_len);
|
|
m->m_len = icmplen + ICMP_MINLEN;
|
|
MH_ALIGN(m, m->m_len);
|
|
icp = mtod(m, struct icmp *);
|
|
if ((u_int)type > ICMP_MAXTYPE)
|
|
panic("icmp_error");
|
|
icmpstat.icps_outhist[type]++;
|
|
icp->icmp_type = type;
|
|
if (type == ICMP_REDIRECT)
|
|
icp->icmp_gwaddr = dest;
|
|
else
|
|
icp->icmp_void = 0;
|
|
if (type == ICMP_PARAMPROB) {
|
|
icp->icmp_pptr = code;
|
|
code = 0;
|
|
}
|
|
icp->icmp_code = code;
|
|
bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, icmplen);
|
|
nip = &icp->icmp_ip;
|
|
nip->ip_len = htons((u_short)(nip->ip_len + oiplen));
|
|
|
|
/*
|
|
* Now, copy old ip header (without options)
|
|
* in front of icmp message.
|
|
*/
|
|
if (m->m_data - sizeof(struct ip) < m->m_pktdat)
|
|
panic("icmp len");
|
|
m->m_data -= sizeof(struct ip);
|
|
m->m_len += sizeof(struct ip);
|
|
m->m_pkthdr.len = m->m_len;
|
|
m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
|
|
nip = mtod(m, struct ip *);
|
|
bcopy((caddr_t)oip, (caddr_t)nip, oiplen);
|
|
nip->ip_len = m->m_len;
|
|
nip->ip_hl = sizeof(struct ip) >> 2;
|
|
nip->ip_p = IPPROTO_ICMP;
|
|
icmp_reflect(m);
|
|
|
|
freeit:
|
|
m_freem(n);
|
|
}
|
|
|
|
static struct sockproto icmproto = { AF_INET, IPPROTO_ICMP };
|
|
static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET };
|
|
static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET };
|
|
static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET };
|
|
struct sockaddr_in icmpmask = { 8, 0 };
|
|
struct in_ifaddr *ifptoia();
|
|
|
|
/*
|
|
* Process a received ICMP message.
|
|
*/
|
|
icmp_input(m, hlen)
|
|
register struct mbuf *m;
|
|
int hlen;
|
|
{
|
|
register struct icmp *icp;
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
int icmplen = ip->ip_len;
|
|
register int i;
|
|
struct in_ifaddr *ia;
|
|
int (*ctlfunc)(), code;
|
|
extern u_char ip_protox[];
|
|
extern struct in_addr in_makeaddr();
|
|
|
|
/*
|
|
* Locate icmp structure in mbuf, and check
|
|
* that not corrupted and of at least minimum length.
|
|
*/
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_input from %x, len %d\n", ip->ip_src, icmplen);
|
|
#endif
|
|
if (icmplen < ICMP_MINLEN) {
|
|
icmpstat.icps_tooshort++;
|
|
goto freeit;
|
|
}
|
|
i = hlen + MIN(icmplen, ICMP_ADVLENMIN);
|
|
if (m->m_len < i && (m = m_pullup(m, i)) == 0) {
|
|
icmpstat.icps_tooshort++;
|
|
return;
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
m->m_len -= hlen;
|
|
m->m_data += hlen;
|
|
icp = mtod(m, struct icmp *);
|
|
if (in_cksum(m, icmplen)) {
|
|
icmpstat.icps_checksum++;
|
|
goto freeit;
|
|
}
|
|
m->m_len += hlen;
|
|
m->m_data -= hlen;
|
|
|
|
#ifdef ICMPPRINTFS
|
|
/*
|
|
* Message type specific processing.
|
|
*/
|
|
if (icmpprintfs)
|
|
printf("icmp_input, type %d code %d\n", icp->icmp_type,
|
|
icp->icmp_code);
|
|
#endif
|
|
if (icp->icmp_type > ICMP_MAXTYPE)
|
|
goto raw;
|
|
icmpstat.icps_inhist[icp->icmp_type]++;
|
|
code = icp->icmp_code;
|
|
switch (icp->icmp_type) {
|
|
|
|
case ICMP_UNREACH:
|
|
if (code > 5)
|
|
goto badcode;
|
|
code += PRC_UNREACH_NET;
|
|
goto deliver;
|
|
|
|
case ICMP_TIMXCEED:
|
|
if (code > 1)
|
|
goto badcode;
|
|
code += PRC_TIMXCEED_INTRANS;
|
|
goto deliver;
|
|
|
|
case ICMP_PARAMPROB:
|
|
if (code)
|
|
goto badcode;
|
|
code = PRC_PARAMPROB;
|
|
goto deliver;
|
|
|
|
case ICMP_SOURCEQUENCH:
|
|
if (code)
|
|
goto badcode;
|
|
code = PRC_QUENCH;
|
|
deliver:
|
|
/*
|
|
* Problem with datagram; advise higher level routines.
|
|
*/
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
|
|
icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
|
|
icmpstat.icps_badlen++;
|
|
goto freeit;
|
|
}
|
|
NTOHS(icp->icmp_ip.ip_len);
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
|
|
#endif
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
|
if (ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput)
|
|
(*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
|
|
(caddr_t) &icp->icmp_ip);
|
|
break;
|
|
|
|
badcode:
|
|
icmpstat.icps_badcode++;
|
|
break;
|
|
|
|
case ICMP_ECHO:
|
|
icp->icmp_type = ICMP_ECHOREPLY;
|
|
goto reflect;
|
|
|
|
case ICMP_TSTAMP:
|
|
if (icmplen < ICMP_TSLEN) {
|
|
icmpstat.icps_badlen++;
|
|
break;
|
|
}
|
|
icp->icmp_type = ICMP_TSTAMPREPLY;
|
|
icp->icmp_rtime = iptime();
|
|
icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
|
|
goto reflect;
|
|
|
|
case ICMP_IREQ:
|
|
#define satosin(sa) ((struct sockaddr_in *)(sa))
|
|
if (in_netof(ip->ip_src) == 0 &&
|
|
(ia = ifptoia(m->m_pkthdr.rcvif)))
|
|
ip->ip_src = in_makeaddr(in_netof(IA_SIN(ia)->sin_addr),
|
|
in_lnaof(ip->ip_src));
|
|
icp->icmp_type = ICMP_IREQREPLY;
|
|
goto reflect;
|
|
|
|
case ICMP_MASKREQ:
|
|
if (icmplen < ICMP_MASKLEN ||
|
|
(ia = ifptoia(m->m_pkthdr.rcvif)) == 0)
|
|
break;
|
|
icp->icmp_type = ICMP_MASKREPLY;
|
|
icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
|
|
if (ip->ip_src.s_addr == 0) {
|
|
if (ia->ia_ifp->if_flags & IFF_BROADCAST)
|
|
ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
|
|
else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
|
|
ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
|
|
}
|
|
reflect:
|
|
ip->ip_len += hlen; /* since ip_input deducts this */
|
|
icmpstat.icps_reflect++;
|
|
icmpstat.icps_outhist[icp->icmp_type]++;
|
|
icmp_reflect(m);
|
|
return;
|
|
|
|
case ICMP_REDIRECT:
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) {
|
|
icmpstat.icps_badlen++;
|
|
break;
|
|
}
|
|
/*
|
|
* Short circuit routing redirects to force
|
|
* immediate change in the kernel's routing
|
|
* tables. The message is also handed to anyone
|
|
* listening on a raw socket (e.g. the routing
|
|
* daemon for use in updating its tables).
|
|
*/
|
|
icmpgw.sin_addr = ip->ip_src;
|
|
icmpdst.sin_addr = icp->icmp_gwaddr;
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("redirect dst %x to %x\n", icp->icmp_ip.ip_dst,
|
|
icp->icmp_gwaddr);
|
|
#endif
|
|
if (code == ICMP_REDIRECT_NET || code == ICMP_REDIRECT_TOSNET) {
|
|
u_long in_netof();
|
|
icmpsrc.sin_addr =
|
|
in_makeaddr(in_netof(icp->icmp_ip.ip_dst), INADDR_ANY);
|
|
in_sockmaskof(icp->icmp_ip.ip_dst, &icmpmask);
|
|
rtredirect((struct sockaddr *)&icmpsrc,
|
|
(struct sockaddr *)&icmpdst,
|
|
(struct sockaddr *)&icmpmask, RTF_GATEWAY,
|
|
(struct sockaddr *)&icmpgw, (struct rtentry **)0);
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
|
pfctlinput(PRC_REDIRECT_NET,
|
|
(struct sockaddr *)&icmpsrc);
|
|
} else {
|
|
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
|
|
rtredirect((struct sockaddr *)&icmpsrc,
|
|
(struct sockaddr *)&icmpdst,
|
|
(struct sockaddr *)0, RTF_GATEWAY | RTF_HOST,
|
|
(struct sockaddr *)&icmpgw, (struct rtentry **)0);
|
|
pfctlinput(PRC_REDIRECT_HOST,
|
|
(struct sockaddr *)&icmpsrc);
|
|
}
|
|
break;
|
|
|
|
/*
|
|
* No kernel processing for the following;
|
|
* just fall through to send to raw listener.
|
|
*/
|
|
case ICMP_ECHOREPLY:
|
|
case ICMP_TSTAMPREPLY:
|
|
case ICMP_IREQREPLY:
|
|
case ICMP_MASKREPLY:
|
|
default:
|
|
break;
|
|
}
|
|
|
|
raw:
|
|
icmpsrc.sin_addr = ip->ip_src;
|
|
icmpdst.sin_addr = ip->ip_dst;
|
|
(void) raw_input(m, &icmproto, (struct sockaddr *)&icmpsrc,
|
|
(struct sockaddr *)&icmpdst);
|
|
return;
|
|
|
|
freeit:
|
|
m_freem(m);
|
|
}
|
|
|
|
/*
|
|
* Reflect the ip packet back to the source
|
|
*/
|
|
icmp_reflect(m)
|
|
struct mbuf *m;
|
|
{
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
register struct in_ifaddr *ia;
|
|
struct in_addr t;
|
|
struct mbuf *opts = 0, *ip_srcroute();
|
|
int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
|
|
|
|
t = ip->ip_dst;
|
|
ip->ip_dst = ip->ip_src;
|
|
/*
|
|
* If the incoming packet was addressed directly to us,
|
|
* use dst as the src for the reply. Otherwise (broadcast
|
|
* or anonymous), use the address which corresponds
|
|
* to the incoming interface.
|
|
*/
|
|
for (ia = in_ifaddr; ia; ia = ia->ia_next) {
|
|
if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
|
|
break;
|
|
if ((ia->ia_ifp->if_flags & IFF_BROADCAST) &&
|
|
t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr)
|
|
break;
|
|
}
|
|
if (ia == (struct in_ifaddr *)0)
|
|
ia = ifptoia(m->m_pkthdr.rcvif);
|
|
if (ia == (struct in_ifaddr *)0)
|
|
ia = in_ifaddr;
|
|
t = IA_SIN(ia)->sin_addr;
|
|
ip->ip_src = t;
|
|
ip->ip_ttl = MAXTTL;
|
|
|
|
if (optlen > 0) {
|
|
register u_char *cp;
|
|
int opt, cnt;
|
|
u_int len;
|
|
|
|
/*
|
|
* Retrieve any source routing from the incoming packet;
|
|
* add on any record-route or timestamp options.
|
|
*/
|
|
cp = (u_char *) (ip + 1);
|
|
if ((opts = ip_srcroute()) == 0 &&
|
|
(opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
|
|
opts->m_len = sizeof(struct in_addr);
|
|
mtod(opts, struct in_addr *)->s_addr = 0;
|
|
}
|
|
if (opts) {
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_reflect optlen %d rt %d => ",
|
|
optlen, opts->m_len);
|
|
#endif
|
|
for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
|
|
opt = cp[IPOPT_OPTVAL];
|
|
if (opt == IPOPT_EOL)
|
|
break;
|
|
if (opt == IPOPT_NOP)
|
|
len = 1;
|
|
else {
|
|
len = cp[IPOPT_OLEN];
|
|
if (len <= 0 || len > cnt)
|
|
break;
|
|
}
|
|
/*
|
|
* should check for overflow, but it "can't happen"
|
|
*/
|
|
if (opt == IPOPT_RR || opt == IPOPT_TS) {
|
|
bcopy((caddr_t)cp,
|
|
mtod(opts, caddr_t) + opts->m_len, len);
|
|
opts->m_len += len;
|
|
}
|
|
}
|
|
if (opts->m_len % 4 != 0) {
|
|
*(mtod(opts, caddr_t) + opts->m_len) = IPOPT_EOL;
|
|
opts->m_len++;
|
|
}
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("%d\n", opts->m_len);
|
|
#endif
|
|
}
|
|
/*
|
|
* Now strip out original options by copying rest of first
|
|
* mbuf's data back, and adjust the IP length.
|
|
*/
|
|
ip->ip_len -= optlen;
|
|
ip->ip_hl = sizeof(struct ip) >> 2;
|
|
m->m_len -= optlen;
|
|
if (m->m_flags & M_PKTHDR)
|
|
m->m_pkthdr.len -= optlen;
|
|
optlen += sizeof(struct ip);
|
|
bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
|
|
(unsigned)(m->m_len - sizeof(struct ip)));
|
|
}
|
|
m->m_flags &= ~(M_BCAST|M_MCAST);
|
|
icmp_send(m, opts);
|
|
if (opts)
|
|
(void)m_free(opts);
|
|
}
|
|
|
|
struct in_ifaddr *
|
|
ifptoia(ifp)
|
|
struct ifnet *ifp;
|
|
{
|
|
register struct in_ifaddr *ia;
|
|
|
|
for (ia = in_ifaddr; ia; ia = ia->ia_next)
|
|
if (ia->ia_ifp == ifp)
|
|
return (ia);
|
|
return ((struct in_ifaddr *)0);
|
|
}
|
|
|
|
/*
|
|
* Send an icmp packet back to the ip level,
|
|
* after supplying a checksum.
|
|
*/
|
|
icmp_send(m, opts)
|
|
register struct mbuf *m;
|
|
struct mbuf *opts;
|
|
{
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
register int hlen;
|
|
register struct icmp *icp;
|
|
|
|
hlen = ip->ip_hl << 2;
|
|
m->m_data += hlen;
|
|
m->m_len -= hlen;
|
|
icp = mtod(m, struct icmp *);
|
|
icp->icmp_cksum = 0;
|
|
icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
|
|
m->m_data -= hlen;
|
|
m->m_len += hlen;
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src);
|
|
#endif
|
|
(void) ip_output(m, opts, (struct route *)0, 0);
|
|
}
|
|
|
|
n_time
|
|
iptime()
|
|
{
|
|
struct timeval atv;
|
|
u_long t;
|
|
|
|
microtime(&atv);
|
|
t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
|
|
return (htonl(t));
|
|
}
|