diff -ru src.release/sys/conf/options src/sys/conf/options
--- src.release/sys/conf/options	2009-04-14 21:14:26.000000000 -0600
+++ src/sys/conf/options	2010-10-05 17:16:20.000000000 -0600
@@ -770,3 +770,6 @@
 
 # Interrupt filtering
 INTR_FILTER             opt_global.h
+
+# Emulab Ping of Death
+ICMP_PINGOFDEATH	opt_icmp_pingofdeath.h
diff -ru src.release/sys/netinet/ip_icmp.c src/sys/netinet/ip_icmp.c
--- src.release/sys/netinet/ip_icmp.c	2009-04-14 21:14:26.000000000 -0600
+++ src/sys/netinet/ip_icmp.c	2010-10-05 17:15:36.000000000 -0600
@@ -134,6 +134,11 @@
 static void	icmp_reflect(struct mbuf *);
 static void	icmp_send(struct mbuf *, struct mbuf *);
 
+#include "opt_icmp_pingofdeath.h"
+#ifdef ICMP_PINGOFDEATH
+static void icmp_pingofdeath(struct icmp *, struct ip *, int);
+#endif
+
 extern	struct protosw inetsw[];
 
 /*
@@ -593,6 +598,12 @@
 #endif
 		break;
 
+#ifdef ICMP_PINGOFDEATH
+	case ICMP_PINGOFDEATH:
+		icmp_pingofdeath(icp, ip, hlen);
+		break;
+#endif
+
 	/*
 	 * No kernel processing for the following;
 	 * just fall through to send to raw listener.
@@ -926,3 +937,112 @@
 	return 0;			/* okay to send packet */
 #undef N
 }
+
+#ifdef ICMP_PINGOFDEATH
+#include <machine/cpu.h>
+#include <sys/syslog.h>
+
+SYSCTL_NODE(_net_inet_icmp, OID_AUTO, ipod, CTLFLAG_RW, 0,
+	"ICMP Ping of Death (IPoD)");
+
+static int ipod_version = 2;
+SYSCTL_INT(_net_inet_icmp_ipod, OID_AUTO, version, CTLFLAG_RD,
+	&ipod_version, 0, "IPoD version");
+
+static int ipod_enabled = 0;
+SYSCTL_INT(_net_inet_icmp_ipod, OID_AUTO, enabled, CTLFLAG_RW,
+	&ipod_enabled, 0, "Enable IPoD");
+
+static unsigned long ipod_host = 0xffffffff;
+SYSCTL_ULONG(_net_inet_icmp_ipod, OID_AUTO, host, CTLFLAG_RW,
+	&ipod_host, 0, "IPv4 address of valid IPoD sender");
+static unsigned long ipod_mask = 0xffffffff;
+SYSCTL_ULONG(_net_inet_icmp_ipod, OID_AUTO, mask, CTLFLAG_RW,
+	&ipod_mask, 0, "IPv4 netmask of valid IPoD sender");
+
+static char ipod_key[32+1] = { "SETMETOSOMETHINGTHIRTYTWOBYTES!!" };
+#define IPOD_CHECK_KEY \
+	(ipod_key[0] != 0)
+#define IPOD_VALID_KEY(d) \
+	(strncmp(ipod_key, (char *)(d), strlen(ipod_key)) == 0)
+
+static int
+ipod_getkey(SYSCTL_HANDLER_ARGS)
+{
+	int error;
+
+	/* XXX fake up a result */
+	error = SYSCTL_OUT(req, "XXXX", 4+1);
+	if (error || !req->newptr)
+		return (error);
+
+	if ((req->newlen - req->newidx) >= sizeof(ipod_key))
+		return (EINVAL);
+
+	arg2 = (req->newlen - req->newidx);
+	error = SYSCTL_IN(req, ipod_key, arg2);
+	memset(&ipod_key[arg2], 0, sizeof(ipod_key) - arg2);
+
+	return (error);
+}
+
+SYSCTL_PROC(_net_inet_icmp_ipod, OID_AUTO, key, CTLTYPE_STRING | CTLFLAG_RW,
+	NULL, 0, ipod_getkey, "A", "");
+
+#if defined(SMP)
+#include <sys/proc.h>
+#include <sys/sched.h>
+#endif
+
+static void
+icmp_pingofdeath(struct icmp *icp, struct ip *ip, int hlen)
+{
+	int doit = 0;
+
+	/*
+	 * If IPOD not enabled or wrong ICMP code, ignore.
+	 */
+	if (!ipod_enabled || icp->icmp_code != 6)
+		return;
+
+	/*
+	 * First check the source address info.
+	 * If host not set, ignore.
+	 */
+	if (ipod_host != 0xffffffff &&
+	    (ntohl(ip->ip_src.s_addr) & ipod_mask) == ipod_host) {
+		/*
+		 * Now check the key if enabled.
+		 * If packet doesn't contain enough data or key
+		 * is otherwise invalid, ignore.
+		 */
+		if (IPOD_CHECK_KEY) {
+			if (ip->ip_len >= strlen(ipod_key) &&
+			    IPOD_VALID_KEY(icp->icmp_data))
+				doit = 1;
+		} else {
+			doit = 1;
+		}
+	}
+
+	if (doit) {
+		ipod_enabled = 0;
+		printf("IPOD: reboot forced by %x...\n",
+		       ntohl(ip->ip_src.s_addr));
+#if defined(SMP)
+		/*
+		 * Bind us to CPU 0 so that all shutdown code runs there.  Some
+		 * systems don't shutdown properly (i.e., ACPI power off) if we
+		 * run on another processor.
+		 */
+		thread_lock(curthread);
+		sched_bind(curthread, 0);
+		thread_unlock(curthread);
+#endif
+		cpu_reset();
+	} else {
+		log(LOG_ERR, "IPOD: from %x rejected\n",
+		    ntohl(ip->ip_src.s_addr));
+	}
+}
+#endif