Ultrix-3.1/sys/net/ip_icmp.c
/**********************************************************************
* Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. *
* All Rights Reserved. *
* Reference "/usr/src/COPYRIGHT" for applicable restrictions. *
**********************************************************************/
/*
* SCCSID: @(#)ip_icmp.c 3.0 4/21/86
* Based on "@(#)ip_icmp.c 1.3 (ULTRIX-32) 11/13/84"
*/
/* ------------------------------------------------------------------------
* Modification History: /sys/netinet/ip_icmp.c
*
* 24 Oct 84 -- jrs
* Added Berkeley changes to rearrange some case handling
* Derived from 4.2BSD, labeled:
* ip_icmp.c 6.5 84/03/13
*
* -----------------------------------------------------------------------
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#ifdef ICMPPRINTFS
/*
* ICMP routines: error generation, receive packet processing, and
* routines to turnaround packets back to the originator, and
* host table maintenance routines.
*/
int icmpprintfs = 0;
#endif
/*
* Generate an error packet of type error
* in response to bad packet ip.
*/
icmp_error(oip, type, code)
struct ip *oip;
int type, code;
{
register unsigned oiplen = oip->ip_hl << 2;
register struct icmp *icp;
struct mbuf *m;
#ifdef pdp11
struct mbuf *om = dtom(oip);
#endif pdp11
struct ip *nip;
#ifdef pdp11
MAPSAVE();
#endif pdp11
#ifdef ICMPPRINTFS
if (icmpprintfs)
printf("icmp_error(%x, %d, %d)\n", oip, type, code);
#endif
icmpstat.icps_error++;
/*
* Make sure that the old IP packet had 8 bytes of data to return;
* if not, don't bother. Also don't EVER error if the old
* packet protocol was ICMP.
*/
if (oip->ip_len < 8) {
icmpstat.icps_oldshort++;
goto free;
}
if (oip->ip_p == IPPROTO_ICMP) {
icmpstat.icps_oldicmp++;
goto free;
}
/*
* First, formulate icmp message
*/
m = m_get(M_DONTWAIT, MT_HEADER);
if (m == NULL)
goto free;
m->m_len = oiplen + 8 + ICMP_MINLEN;
m->m_off = MMAXOFF - m->m_len;
icp = mtod(m, struct icmp *);
if ((u_int)type > ICMP_IREQREPLY)
panic("icmp_error");
icmpstat.icps_outhist[type]++;
icp->icmp_type = type;
icp->icmp_void = 0;
if (type == ICMP_PARAMPROB) {
icp->icmp_pptr = code;
code = 0;
}
icp->icmp_code = code;
#ifndef pdp11
bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, oiplen + 8);
#else pdp11
MBCOPY(om, 0, m, (&icp->icmp_ip - icp), oiplen + 8);
#endif pdp11
nip = &icp->icmp_ip;
nip->ip_len += oiplen;
nip->ip_len = htons((u_short)nip->ip_len);
/*
* Now, copy old ip header in front of icmp
* message. This allows us to reuse any source
* routing info present.
*/
m->m_off -= oiplen;
nip = mtod(m, struct ip *);
#ifndef pdp11
bcopy((caddr_t)oip, (caddr_t)nip, oiplen);
#else pdp11
MBCOPY(om, 0, m, 0, oiplen);
#endif pdp11
nip->ip_len = m->m_len + oiplen;
nip->ip_p = IPPROTO_ICMP;
/* icmp_send adds ip header to m_off and m_len, so we deduct here */
m->m_off += oiplen;
icmp_reflect(nip);
free:
#ifdef vax
m_freem(dtom(oip));
#else pdp11
m_freem(om);
MAPREST();
#endif
}
static struct sockproto icmproto = { AF_INET, IPPROTO_ICMP };
static struct sockaddr_in icmpsrc = { AF_INET };
static struct sockaddr_in icmpdst = { AF_INET };
/*
* Process a received ICMP message.
*/
icmp_input(m)
struct mbuf *m;
{
register struct icmp *icp;
#ifndef pdp11
register struct ip *ip = mtod(m, struct ip *);
int icmplen = ip->ip_len, hlen = ip->ip_hl << 2;
#else pdp11
register struct ip *ip;
int icmplen, hlen;
#endif pdp11
register int i;
int (*ctlfunc)(), code;
extern u_char ip_protox[];
#ifdef pdp11
#define return goto finishup
MAPSAVE();
ip = mtod(m, struct ip *);
icmplen = ip->ip_len;
hlen = ip->ip_hl << 2;
#endif pdp11
/*
* 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 free;
}
/* THIS LENGTH CHECK STILL MISSES ANY IP OPTIONS IN ICMP_IP */
i = MIN(icmplen, ICMP_ADVLENMIN + hlen);
if ((m->m_off > MMAXOFF || 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_off += hlen;
icp = mtod(m, struct icmp *);
if (in_cksum(m, icmplen)) {
icmpstat.icps_checksum++;
goto free;
}
#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_IREQREPLY)
goto free;
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.
*/
icp->icmp_ip.ip_len = ntohs((u_short)icp->icmp_ip.ip_len);
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) {
icmpstat.icps_badlen++;
goto free;
}
#ifdef ICMPPRINTFS
if (icmpprintfs)
printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
#endif
#ifndef pdp11
if (ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput){
(*ctlfunc)(code, (caddr_t)icp);
#else pdp11
if ((i = icp->icmp_ip.ip_p) >= IPPROTO_MAX)
i = IPPROTO_psudoRAW;
if (ctlfunc = inetsw[ip_protox[i]].pr_ctlinput){
struct icmp *icpcopy;
icpcopy = (struct icmp *)m_sget(icmplen);
if (icpcopy == 0)
goto free;
bcopy((caddr_t)icp, (caddr_t)icpcopy, icmplen);
(*ctlfunc)(code, (caddr_t)icpcopy);
m_sfree((caddr_t)icpcopy);
#endif pdp11
}
goto free;
badcode:
icmpstat.icps_badcode++;
goto free;
case ICMP_ECHO:
icp->icmp_type = ICMP_ECHOREPLY;
goto reflect;
case ICMP_TSTAMP:
if (icmplen < ICMP_TSLEN) {
icmpstat.icps_badlen++;
goto free;
}
icp->icmp_type = ICMP_TSTAMPREPLY;
icp->icmp_rtime = iptime();
icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
goto reflect;
case ICMP_IREQ:
#ifdef notdef
/* fill in source address zero fields! */
goto reflect;
#else
goto free; /* not yet implemented: ignore */
#endif
case ICMP_REDIRECT:
if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) {
icmpstat.icps_badlen++;
goto free;
}
/*
* 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 it's tables).
*/
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
icmpdst.sin_addr = icp->icmp_gwaddr;
rtredirect((struct sockaddr *)&icmpsrc,
(struct sockaddr *)&icmpdst,
(code == ICMP_REDIRECT_NET || code == ICMP_REDIRECT_TOSNET) ?
RTF_GATEWAY : (RTF_GATEWAY | RTF_HOST));
/* FALL THROUGH */
case ICMP_ECHOREPLY:
case ICMP_TSTAMPREPLY:
case ICMP_IREQREPLY:
icmpsrc.sin_addr = ip->ip_src;
icmpdst.sin_addr = ip->ip_dst;
raw_input(dtom(icp), &icmproto, (struct sockaddr *)&icmpsrc,
(struct sockaddr *)&icmpdst);
return;
default:
goto free;
}
reflect:
ip->ip_len += hlen; /* since ip_input deducts this */
icmpstat.icps_reflect++;
icmp_reflect(ip);
return;
free:
#ifdef vax
m_freem(dtom(ip));
#else pdp11
m_freem(m);
#undef return
finishup:
MAPREST();
#endif pdp11
}
/*
* Reflect the ip packet back to the source
* TODO: rearrange ip source routing options.
*/
static
icmp_reflect(ip)
struct ip *ip;
{
struct in_addr t;
t = ip->ip_dst;
ip->ip_dst = ip->ip_src;
ip->ip_src = t;
icmp_send(ip);
}
/*
* Send an icmp packet back to the ip level,
* after supplying a checksum.
#ifdef pdp11
* No need to save ka5 here. We are only called by icmp_reflect,
* and icmp_reflect is only called by routines that alread save
* and restore ka5.
#endif
*/
static
icmp_send(ip)
struct ip *ip;
{
register int hlen;
register struct icmp *icp;
register struct mbuf *m;
m = dtom(ip);
hlen = ip->ip_hl << 2;
icp = mtod(m, struct icmp *);
icp->icmp_cksum = 0;
icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
m->m_off -= 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, (struct mbuf *)0, (struct route *)0, 0);
}
n_time
iptime()
{
int s = spl6();
u_long t;
#ifdef pdp11
extern int hz;
t = (time % (24*60*60)) * 1000 + lbolt * hz;
#else pdp11
t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000;
#endif pdp11
splx(s);
return (htonl(t));
}