872 lines
22 KiB
C
872 lines
22 KiB
C
/*
|
|
* Copyright (c) 1982, 1986, 1988, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. 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_icmp.c 8.2 (Berkeley) 1/4/94
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include "opt_ipsec.h"
|
|
#include "opt_mac.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/mac.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/time.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_types.h>
|
|
#include <net/route.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/in_var.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/ip_icmp.h>
|
|
#include <netinet/ip_var.h>
|
|
#include <netinet/icmp_var.h>
|
|
|
|
#ifdef IPSEC
|
|
#include <netinet6/ipsec.h>
|
|
#include <netkey/key.h>
|
|
#endif
|
|
|
|
#ifdef FAST_IPSEC
|
|
#include <netipsec/ipsec.h>
|
|
#include <netipsec/key.h>
|
|
#define IPSEC
|
|
#endif
|
|
|
|
#include <machine/in_cksum.h>
|
|
|
|
/*
|
|
* ICMP routines: error generation, receive packet processing, and
|
|
* routines to turnaround packets back to the originator, and
|
|
* host table maintenance routines.
|
|
*/
|
|
|
|
static struct icmpstat icmpstat;
|
|
SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RW,
|
|
&icmpstat, icmpstat, "");
|
|
|
|
static int icmpmaskrepl = 0;
|
|
SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
|
|
&icmpmaskrepl, 0, "");
|
|
|
|
static int drop_redirect = 0;
|
|
SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_RW,
|
|
&drop_redirect, 0, "");
|
|
|
|
static int log_redirect = 0;
|
|
SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW,
|
|
&log_redirect, 0, "");
|
|
|
|
static int icmplim = 200;
|
|
SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW,
|
|
&icmplim, 0, "");
|
|
|
|
static int icmplim_output = 1;
|
|
SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_RW,
|
|
&icmplim_output, 0, "");
|
|
|
|
/*
|
|
* ICMP broadcast echo sysctl
|
|
*/
|
|
|
|
static int icmpbmcastecho = 0;
|
|
SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW,
|
|
&icmpbmcastecho, 0, "");
|
|
|
|
|
|
#ifdef ICMPPRINTFS
|
|
int icmpprintfs = 0;
|
|
#endif
|
|
|
|
static void icmp_reflect(struct mbuf *);
|
|
static void icmp_send(struct mbuf *, struct mbuf *, struct route *);
|
|
static int ip_next_mtu(int, int);
|
|
|
|
extern struct protosw inetsw[];
|
|
|
|
/*
|
|
* Generate an error packet of type error
|
|
* in response to bad packet ip.
|
|
*/
|
|
void
|
|
icmp_error(n, type, code, dest, destifp)
|
|
struct mbuf *n;
|
|
int type, code;
|
|
n_long dest;
|
|
struct ifnet *destifp;
|
|
{
|
|
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(%p, %x, %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;
|
|
}
|
|
/* Don't send error in response to a multicast or broadcast packet */
|
|
if (n->m_flags & (M_BCAST|M_MCAST))
|
|
goto freeit;
|
|
/*
|
|
* First, formulate icmp message
|
|
*/
|
|
m = m_gethdr(M_NOWAIT, MT_HEADER);
|
|
if (m == NULL)
|
|
goto freeit;
|
|
#ifdef MAC
|
|
mac_create_mbuf_netlayer(n, m);
|
|
#endif
|
|
icmplen = min(oiplen + 8, oip->ip_len);
|
|
if (icmplen < sizeof(struct ip))
|
|
panic("icmp_error: bad length");
|
|
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.s_addr = dest;
|
|
else {
|
|
icp->icmp_void = 0;
|
|
/*
|
|
* The following assignments assume an overlay with the
|
|
* zeroed icmp_void field.
|
|
*/
|
|
if (type == ICMP_PARAMPROB) {
|
|
icp->icmp_pptr = code;
|
|
code = 0;
|
|
} else if (type == ICMP_UNREACH &&
|
|
code == ICMP_UNREACH_NEEDFRAG && destifp) {
|
|
icp->icmp_nextmtu = htons(destifp->if_mtu);
|
|
}
|
|
}
|
|
|
|
icp->icmp_code = code;
|
|
m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
|
|
nip = &icp->icmp_ip;
|
|
|
|
/*
|
|
* Convert fields to network representation.
|
|
*/
|
|
nip->ip_len = htons(nip->ip_len);
|
|
nip->ip_off = htons(nip->ip_off);
|
|
|
|
/*
|
|
* 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, sizeof(struct ip));
|
|
nip->ip_len = m->m_len;
|
|
nip->ip_v = IPVERSION;
|
|
nip->ip_hl = 5;
|
|
nip->ip_p = IPPROTO_ICMP;
|
|
nip->ip_tos = 0;
|
|
icmp_reflect(m);
|
|
|
|
freeit:
|
|
m_freem(n);
|
|
}
|
|
|
|
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 };
|
|
|
|
/*
|
|
* Process a received ICMP message.
|
|
*/
|
|
void
|
|
icmp_input(m, off)
|
|
register struct mbuf *m;
|
|
int off;
|
|
{
|
|
int hlen = off;
|
|
register struct icmp *icp;
|
|
register struct ip *ip = mtod(m, struct ip *);
|
|
int icmplen = ip->ip_len;
|
|
register int i;
|
|
struct in_ifaddr *ia;
|
|
void (*ctlfunc)(int, struct sockaddr *, void *);
|
|
int code;
|
|
|
|
/*
|
|
* Locate icmp structure in mbuf, and check
|
|
* that not corrupted and of at least minimum length.
|
|
*/
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs) {
|
|
char buf[4 * sizeof "123"];
|
|
strcpy(buf, inet_ntoa(ip->ip_src));
|
|
printf("icmp_input from %s to %s, len %d\n",
|
|
buf, inet_ntoa(ip->ip_dst), 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;
|
|
|
|
if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
|
|
/*
|
|
* Deliver very specific ICMP type only.
|
|
*/
|
|
switch (icp->icmp_type) {
|
|
case ICMP_UNREACH:
|
|
case ICMP_TIMXCEED:
|
|
break;
|
|
default:
|
|
goto freeit;
|
|
}
|
|
}
|
|
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs)
|
|
printf("icmp_input, type %d code %d\n", icp->icmp_type,
|
|
icp->icmp_code);
|
|
#endif
|
|
|
|
/*
|
|
* Message type specific processing.
|
|
*/
|
|
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:
|
|
switch (code) {
|
|
case ICMP_UNREACH_NET:
|
|
case ICMP_UNREACH_HOST:
|
|
case ICMP_UNREACH_SRCFAIL:
|
|
case ICMP_UNREACH_NET_UNKNOWN:
|
|
case ICMP_UNREACH_HOST_UNKNOWN:
|
|
case ICMP_UNREACH_ISOLATED:
|
|
case ICMP_UNREACH_TOSNET:
|
|
case ICMP_UNREACH_TOSHOST:
|
|
case ICMP_UNREACH_HOST_PRECEDENCE:
|
|
case ICMP_UNREACH_PRECEDENCE_CUTOFF:
|
|
code = PRC_UNREACH_NET;
|
|
break;
|
|
|
|
case ICMP_UNREACH_NEEDFRAG:
|
|
code = PRC_MSGSIZE;
|
|
break;
|
|
|
|
/*
|
|
* RFC 1122, Sections 3.2.2.1 and 4.2.3.9.
|
|
* Treat subcodes 2,3 as immediate RST
|
|
*/
|
|
case ICMP_UNREACH_PROTOCOL:
|
|
case ICMP_UNREACH_PORT:
|
|
code = PRC_UNREACH_PORT;
|
|
break;
|
|
|
|
case ICMP_UNREACH_NET_PROHIB:
|
|
case ICMP_UNREACH_HOST_PROHIB:
|
|
case ICMP_UNREACH_FILTER_PROHIB:
|
|
code = PRC_UNREACH_ADMIN_PROHIB;
|
|
break;
|
|
|
|
default:
|
|
goto badcode;
|
|
}
|
|
goto deliver;
|
|
|
|
case ICMP_TIMXCEED:
|
|
if (code > 1)
|
|
goto badcode;
|
|
code += PRC_TIMXCEED_INTRANS;
|
|
goto deliver;
|
|
|
|
case ICMP_PARAMPROB:
|
|
if (code > 1)
|
|
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;
|
|
}
|
|
icp->icmp_ip.ip_len = ntohs(icp->icmp_ip.ip_len);
|
|
/* Discard ICMP's in response to multicast packets */
|
|
if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
|
|
goto badcode;
|
|
#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 1
|
|
/*
|
|
* MTU discovery:
|
|
* If we got a needfrag and there is a host route to the
|
|
* original destination, and the MTU is not locked, then
|
|
* set the MTU in the route to the suggested new value
|
|
* (if given) and then notify as usual. The ULPs will
|
|
* notice that the MTU has changed and adapt accordingly.
|
|
* If no new MTU was suggested, then we guess a new one
|
|
* less than the current value. If the new MTU is
|
|
* unreasonably small (arbitrarily set at 296), then
|
|
* we reset the MTU to the interface value and enable the
|
|
* lock bit, indicating that we are no longer doing MTU
|
|
* discovery.
|
|
*/
|
|
if (code == PRC_MSGSIZE) {
|
|
struct rtentry *rt;
|
|
int mtu;
|
|
|
|
rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
|
|
RTF_CLONING | RTF_PRCLONING);
|
|
if (rt && (rt->rt_flags & RTF_HOST)
|
|
&& !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
|
|
mtu = ntohs(icp->icmp_nextmtu);
|
|
if (!mtu)
|
|
mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
|
|
1);
|
|
#ifdef DEBUG_MTUDISC
|
|
printf("MTU for %s reduced to %d\n",
|
|
inet_ntoa(icmpsrc.sin_addr), mtu);
|
|
#endif
|
|
if (mtu < 296) {
|
|
/* rt->rt_rmx.rmx_mtu =
|
|
rt->rt_ifp->if_mtu; */
|
|
rt->rt_rmx.rmx_locks |= RTV_MTU;
|
|
} else if (rt->rt_rmx.rmx_mtu > mtu) {
|
|
rt->rt_rmx.rmx_mtu = mtu;
|
|
}
|
|
}
|
|
if (rt)
|
|
RTFREE(rt);
|
|
}
|
|
|
|
#endif
|
|
/*
|
|
* XXX if the packet contains [IPv4 AH TCP], we can't make a
|
|
* notification to TCP layer.
|
|
*/
|
|
ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
|
|
if (ctlfunc)
|
|
(*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
|
|
(void *)&icp->icmp_ip);
|
|
break;
|
|
|
|
badcode:
|
|
icmpstat.icps_badcode++;
|
|
break;
|
|
|
|
case ICMP_ECHO:
|
|
if (!icmpbmcastecho
|
|
&& (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
|
|
icmpstat.icps_bmcastecho++;
|
|
break;
|
|
}
|
|
icp->icmp_type = ICMP_ECHOREPLY;
|
|
if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
|
|
goto freeit;
|
|
else
|
|
goto reflect;
|
|
|
|
case ICMP_TSTAMP:
|
|
if (!icmpbmcastecho
|
|
&& (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
|
|
icmpstat.icps_bmcasttstamp++;
|
|
break;
|
|
}
|
|
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! */
|
|
if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
|
|
goto freeit;
|
|
else
|
|
goto reflect;
|
|
|
|
case ICMP_MASKREQ:
|
|
if (icmpmaskrepl == 0)
|
|
break;
|
|
/*
|
|
* We are not able to respond with all ones broadcast
|
|
* unless we receive it over a point-to-point interface.
|
|
*/
|
|
if (icmplen < ICMP_MASKLEN)
|
|
break;
|
|
switch (ip->ip_dst.s_addr) {
|
|
|
|
case INADDR_BROADCAST:
|
|
case INADDR_ANY:
|
|
icmpdst.sin_addr = ip->ip_src;
|
|
break;
|
|
|
|
default:
|
|
icmpdst.sin_addr = ip->ip_dst;
|
|
}
|
|
ia = (struct in_ifaddr *)ifaof_ifpforaddr(
|
|
(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
|
|
if (ia == 0)
|
|
break;
|
|
if (ia->ia_ifp == 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 (log_redirect) {
|
|
u_long src, dst, gw;
|
|
|
|
src = ntohl(ip->ip_src.s_addr);
|
|
dst = ntohl(icp->icmp_ip.ip_dst.s_addr);
|
|
gw = ntohl(icp->icmp_gwaddr.s_addr);
|
|
printf("icmp redirect from %d.%d.%d.%d: "
|
|
"%d.%d.%d.%d => %d.%d.%d.%d\n",
|
|
(int)(src >> 24), (int)((src >> 16) & 0xff),
|
|
(int)((src >> 8) & 0xff), (int)(src & 0xff),
|
|
(int)(dst >> 24), (int)((dst >> 16) & 0xff),
|
|
(int)((dst >> 8) & 0xff), (int)(dst & 0xff),
|
|
(int)(gw >> 24), (int)((gw >> 16) & 0xff),
|
|
(int)((gw >> 8) & 0xff), (int)(gw & 0xff));
|
|
}
|
|
if (drop_redirect)
|
|
break;
|
|
if (code > 3)
|
|
goto badcode;
|
|
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
|
|
icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
|
|
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) {
|
|
char buf[4 * sizeof "123"];
|
|
strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
|
|
|
|
printf("redirect dst %s to %s\n",
|
|
buf, inet_ntoa(icp->icmp_gwaddr));
|
|
}
|
|
#endif
|
|
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);
|
|
#ifdef IPSEC
|
|
key_sa_routechange((struct sockaddr *)&icmpsrc);
|
|
#endif
|
|
break;
|
|
|
|
/*
|
|
* No kernel processing for the following;
|
|
* just fall through to send to raw listener.
|
|
*/
|
|
case ICMP_ECHOREPLY:
|
|
case ICMP_ROUTERADVERT:
|
|
case ICMP_ROUTERSOLICIT:
|
|
case ICMP_TSTAMPREPLY:
|
|
case ICMP_IREQREPLY:
|
|
case ICMP_MASKREPLY:
|
|
default:
|
|
break;
|
|
}
|
|
|
|
raw:
|
|
rip_input(m, off);
|
|
return;
|
|
|
|
freeit:
|
|
m_freem(m);
|
|
}
|
|
|
|
/*
|
|
* Reflect the ip packet back to the source
|
|
*/
|
|
static void
|
|
icmp_reflect(m)
|
|
struct mbuf *m;
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
struct ifaddr *ifa;
|
|
struct in_ifaddr *ia;
|
|
struct in_addr t;
|
|
struct mbuf *opts = 0;
|
|
int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
|
|
struct route *ro = NULL, rt;
|
|
|
|
if (!in_canforward(ip->ip_src) &&
|
|
((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
|
|
(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
|
|
m_freem(m); /* Bad return address */
|
|
icmpstat.icps_badaddr++;
|
|
goto done; /* Ip_output() will check for broadcast */
|
|
}
|
|
t = ip->ip_dst;
|
|
ip->ip_dst = ip->ip_src;
|
|
ro = &rt;
|
|
bzero(ro, sizeof(*ro));
|
|
/*
|
|
* 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.
|
|
*/
|
|
LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash)
|
|
if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
|
|
goto match;
|
|
if (m->m_pkthdr.rcvif != NULL &&
|
|
m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
|
|
TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
|
|
if (ifa->ifa_addr->sa_family != AF_INET)
|
|
continue;
|
|
ia = ifatoia(ifa);
|
|
if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
|
|
t.s_addr)
|
|
goto match;
|
|
}
|
|
}
|
|
ia = ip_rtaddr(ip->ip_dst, ro);
|
|
/* We need a route to do anything useful. */
|
|
if (ia == NULL) {
|
|
m_freem(m);
|
|
icmpstat.icps_noroute++;
|
|
goto done;
|
|
}
|
|
match:
|
|
t = IA_SIN(ia)->sin_addr;
|
|
ip->ip_src = t;
|
|
ip->ip_ttl = ip_defttl;
|
|
|
|
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_NOWAIT, 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 {
|
|
if (cnt < IPOPT_OLEN + sizeof(*cp))
|
|
break;
|
|
len = cp[IPOPT_OLEN];
|
|
if (len < IPOPT_OLEN + sizeof(*cp) ||
|
|
len > cnt)
|
|
break;
|
|
}
|
|
/*
|
|
* Should check for overflow, but it "can't happen"
|
|
*/
|
|
if (opt == IPOPT_RR || opt == IPOPT_TS ||
|
|
opt == IPOPT_SECURITY) {
|
|
bcopy((caddr_t)cp,
|
|
mtod(opts, caddr_t) + opts->m_len, len);
|
|
opts->m_len += len;
|
|
}
|
|
}
|
|
/* Terminate & pad, if necessary */
|
|
cnt = opts->m_len % 4;
|
|
if (cnt) {
|
|
for (; cnt < 4; cnt++) {
|
|
*(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_v = IPVERSION;
|
|
ip->ip_hl = 5;
|
|
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, ro);
|
|
done:
|
|
if (opts)
|
|
(void)m_free(opts);
|
|
if (ro && ro->ro_rt)
|
|
RTFREE(ro->ro_rt);
|
|
}
|
|
|
|
/*
|
|
* Send an icmp packet back to the ip level,
|
|
* after supplying a checksum.
|
|
*/
|
|
static void
|
|
icmp_send(m, opts, rt)
|
|
register struct mbuf *m;
|
|
struct mbuf *opts;
|
|
struct route *rt;
|
|
{
|
|
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;
|
|
m->m_pkthdr.rcvif = (struct ifnet *)0;
|
|
#ifdef ICMPPRINTFS
|
|
if (icmpprintfs) {
|
|
char buf[4 * sizeof "123"];
|
|
strcpy(buf, inet_ntoa(ip->ip_dst));
|
|
printf("icmp_send dst %s src %s\n",
|
|
buf, inet_ntoa(ip->ip_src));
|
|
}
|
|
#endif
|
|
(void) ip_output(m, opts, rt, 0, NULL, NULL);
|
|
}
|
|
|
|
n_time
|
|
iptime()
|
|
{
|
|
struct timeval atv;
|
|
u_long t;
|
|
|
|
getmicrotime(&atv);
|
|
t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
|
|
return (htonl(t));
|
|
}
|
|
|
|
#if 1
|
|
/*
|
|
* Return the next larger or smaller MTU plateau (table from RFC 1191)
|
|
* given current value MTU. If DIR is less than zero, a larger plateau
|
|
* is returned; otherwise, a smaller value is returned.
|
|
*/
|
|
static int
|
|
ip_next_mtu(mtu, dir)
|
|
int mtu;
|
|
int dir;
|
|
{
|
|
static int mtutab[] = {
|
|
65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
|
|
68, 0
|
|
};
|
|
int i;
|
|
|
|
for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
|
|
if (mtu >= mtutab[i])
|
|
break;
|
|
}
|
|
|
|
if (dir < 0) {
|
|
if (i == 0) {
|
|
return 0;
|
|
} else {
|
|
return mtutab[i - 1];
|
|
}
|
|
} else {
|
|
if (mtutab[i] == 0) {
|
|
return 0;
|
|
} else if(mtu > mtutab[i]) {
|
|
return mtutab[i];
|
|
} else {
|
|
return mtutab[i + 1];
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* badport_bandlim() - check for ICMP bandwidth limit
|
|
*
|
|
* Return 0 if it is ok to send an ICMP error response, -1 if we have
|
|
* hit our bandwidth limit and it is not ok.
|
|
*
|
|
* If icmplim is <= 0, the feature is disabled and 0 is returned.
|
|
*
|
|
* For now we separate the TCP and UDP subsystems w/ different 'which'
|
|
* values. We may eventually remove this separation (and simplify the
|
|
* code further).
|
|
*
|
|
* Note that the printing of the error message is delayed so we can
|
|
* properly print the icmp error rate that the system was trying to do
|
|
* (i.e. 22000/100 pps, etc...). This can cause long delays in printing
|
|
* the 'final' error, but it doesn't make sense to solve the printing
|
|
* delay with more complex code.
|
|
*/
|
|
|
|
int
|
|
badport_bandlim(int which)
|
|
{
|
|
#define N(a) (sizeof (a) / sizeof (a[0]))
|
|
static struct rate {
|
|
const char *type;
|
|
struct timeval lasttime;
|
|
int curpps;;
|
|
} rates[BANDLIM_MAX+1] = {
|
|
{ "icmp unreach response" },
|
|
{ "icmp ping response" },
|
|
{ "icmp tstamp response" },
|
|
{ "closed port RST response" },
|
|
{ "open port RST response" }
|
|
};
|
|
|
|
/*
|
|
* Return ok status if feature disabled or argument out of range.
|
|
*/
|
|
if (icmplim > 0 && (u_int) which < N(rates)) {
|
|
struct rate *r = &rates[which];
|
|
int opps = r->curpps;
|
|
|
|
if (!ppsratecheck(&r->lasttime, &r->curpps, icmplim))
|
|
return -1; /* discard packet */
|
|
/*
|
|
* If we've dropped below the threshold after having
|
|
* rate-limited traffic print the message. This preserves
|
|
* the previous behaviour at the expense of added complexity.
|
|
*/
|
|
if (icmplim_output && opps > icmplim)
|
|
printf("Limiting %s from %d to %d packets/sec\n",
|
|
r->type, opps, icmplim);
|
|
}
|
|
return 0; /* okay to send packet */
|
|
#undef N
|
|
}
|