mike%brl-vgr@sri-unix.UUCP (12/14/83)
From: Michael John Muuss <mike@brl-vgr>
Index: sys/netinet/ip_icmp.c 4.2BSD
Description:
When using a "ping" program to send ICMP_ECHO packets onto
the network, a steady 20% of them are lost, regardless of
interface, including the software loopback driver.
The problem is that ip_icmp is incorrectly looking in
the sequence number and ID field of the ICMP header,
as if this was an "error advice" packet much like ICMP_REDIRECT.
Repeat-By:
Ping the loopback device. Ping program availible on request.
(Pitty that one was not included with 4.2)
Fix:
A little code has to be rearranged in ip_icmp.c, around line 200+.
******* ORIGINAL CODE *******
goto free; /* not yet implemented: ignore */
#endif
case ICMP_REDIRECT:
case ICMP_ECHOREPLY:
case ICMP_TSTAMPREPLY:
case ICMP_IREQREPLY:
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).
*/
if (icp->icmp_type == ICMP_REDIRECT) {
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
icmpdst.sin_addr = icp->icmp_gwaddr;
rtredirect((struct sockaddr *)&icmpsrc,
(struct sockaddr *)&icmpdst);
}
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;
********** Correct code **********
goto free; /* not yet implemented: ignore */
#endif
case ICMP_R