/*------------------------------------------------------------------------
* icmp - send an ICMP message
*------------------------------------------------------------------------
*/
int
icmp(u_short type, u_short code, IPaddr dst, void *pa1, void *pa2)
{
struct ep *pep;
struct ip *pip;
struct icmp *pic;
Bool isresp, iserr;
int datalen;
IcmpOutMsgs++;
pep = icsetbuf(type, pa1, &isresp, &iserr);
if (pep == 0) {
IcmpOutErrors++;
return SYSERR;
}
pip = (struct ip *)pep->ep_data;
pic = (struct icmp *) pip->ip_data;
datalen = IC_HLEN;
/* we fill in the source here, so routing won't break it */
if (isresp) {
if (iserr) {
if (!icerrok(pep)) {
freebuf(pep);
return OK;
}
memcpy(pic->ic_data, pip, IP_HLEN(pip)+8);
datalen += IP_HLEN(pip)+8;
}
icsetsrc(pip);
} else
pip->ip_src = ip_anyaddr;
pip->ip_dst = dst;
pic->ic_type = (char) type;
pic->ic_code = (char) code;
if (!isresp) {
if (type == ICT_ECHORQ)
pic->ic_seq = (int) pa1;
else
pic->ic_seq = 0;
pic->ic_id = getpid();
}
datalen += icsetdata(type, pip, pa2);
pic->ic_cksum = 0;
pic->ic_cksum = cksum((WORD *)pic, datalen);
ipsend(dst, pep, datalen, IPT_ICMP, IPP_INCTL, IP_TTL);
return OK;
}
/*------------------------------------------------------------------------
* icmp_in - handle ICMP packet coming in from the network
*------------------------------------------------------------------------
*/
int
icmp_in(struct netif *pni, struct ep *pep)
{
struct ip *pip;
struct icmp *pic;
int i, len;
pip = (struct ip *)pep->ep_data;
pic = (struct icmp *) pip->ip_data;
len = pip->ip_len - IP_HLEN(pip);
if (cksum((WORD *)pic, len)) {
IcmpInErrors++;
freebuf(pep);
return SYSERR;
}
IcmpInMsgs++;
switch(pic->ic_type) {
case ICT_ECHORQ:
IcmpInEchos++;
return icmp(ICT_ECHORP, 0, pip->ip_src, pep, 0);
case ICT_MASKRQ:
IcmpInAddrMasks++;
if (!gateway) {
freebuf(pep);
return OK;
}
pic->ic_type = (char) ICT_MASKRP;
*(IPaddr *)pic->ic_data = netmask(pip->ip_dst);
break;
case ICT_MASKRP:
IcmpInAddrMaskReps++;
for (i=0; i<Net.nif; ++i)
if (nif[i].ni_ip == pip->ip_dst)
break;
if (i != Net.nif) {
setmask(i, *(IPaddr *)pic->ic_data);
send(pic->ic_id, ICT_MASKRP);
}
freebuf(pep);
return OK;
case ICT_ECHORP:
IcmpInEchoReps++;
if (send(pic->ic_id, (int)pep) != OK)
freebuf(pep);
return OK;
case ICT_REDIRECT:
IcmpInRedirects++;
icredirect(pep);
return OK;
case ICT_DESTUR: IcmpInDestUnreachs++; freebuf(pep); return OK;
case ICT_SRCQ: IcmpInSrcQuenchs++; freebuf(pep); return OK;
case ICT_TIMEX: IcmpInTimeExcds++; freebuf(pep); return OK;
case ICT_PARAMP: IcmpInParmProbs++; freebuf(pep); return OK;
case ICT_TIMERQ: IcmpInTimestamps++; freebuf(pep); return OK;
case ICT_TIMERP: IcmpInTimestampReps++; freebuf(pep); return OK;
default:
IcmpInErrors++;
freebuf(pep);
return OK;
}
icsetsrc(pip);
len = pip->ip_len - IP_HLEN(pip);
pic->ic_cksum = 0;
pic->ic_cksum = cksum((WORD *)pic, len);
IcmpOutMsgs++;
ipsend(pip->ip_dst, pep, len, IPT_ICMP, IPP_INCTL, IP_TTL);
return OK;
}
