--- arpd.orig/arpd.c	2003-02-09 05:20:40.000000000 +0100
+++ arpd/arpd.c	2014-03-16 08:11:53.000000000 +0100
@@ -70,7 +70,7 @@ static int			 arpd_sig;
 static void
 usage(void)
 {
-	fprintf(stderr, "Usage: arpd [-d] [-i interface] [net]\n");
+	fprintf(stderr, "Usage: arpd [-d] [-i interface] [-a 'pcap_expr'] [{host|net|range} ...]\n");
 	exit(1);
 }
 
@@ -182,7 +182,7 @@ arpd_expandips(int naddresses, char **ad
 }
 
 static void
-arpd_init(char *dev, int naddresses, char **addresses)
+arpd_init(char *dev, char *and_pcap_exp, int naddresses, char **addresses)
 {
 	struct bpf_program fcode;
 	char filter[1024], ebuf[PCAP_ERRBUF_SIZE], *dst;
@@ -214,9 +214,13 @@ arpd_init(char *dev, int naddresses, cha
 		errx(1, "bad interface configuration: not IP or Ethernet");
 	arpd_ifent.intf_addr.addr_bits = IP_ADDR_BITS;
 	
-	snprintf(filter, sizeof(filter), "arp %s%s%s and not ether src %s",
+	snprintf(filter, sizeof(filter), "arp %s%s%s and not ether src %s%s%s%s",
 	    dst ? "and (" : "", dst ? dst : "", dst ? ")" : "",
-	    addr_ntoa(&arpd_ifent.intf_link_addr));
+	    addr_ntoa(&arpd_ifent.intf_link_addr),
+	    and_pcap_exp ? " and (" : "",
+	    and_pcap_exp ? and_pcap_exp : "",
+	    and_pcap_exp ? ")" : ""
+	    );
 	
 	if ((arpd_pcap = pcap_open_live(dev, 128, 0, 500, ebuf)) == NULL)
 		errx(1, "pcap_open_live: %s", ebuf);
@@ -265,7 +269,7 @@ arpd_send(eth_t *eth, int op,
 	    spa->addr_ip, tha->addr_eth, tpa->addr_ip);
 	
 	if (op == ARP_OP_REQUEST) {
-		syslog(LOG_DEBUG, __FUNCTION__ ": who-has %s tell %s",
+		syslog(LOG_DEBUG, "%s: who-has %s tell %s", __FUNCTION__,
 		    addr_ntoa(tpa), addr_ntoa(spa));
 	} else if (op == ARP_OP_REPLY) {
 		syslog(LOG_INFO, "arp reply %s is-at %s",
@@ -282,7 +286,7 @@ arpd_lookup(struct addr *addr)
 	int error;
 
 	if (addr_cmp(addr, &arpd_ifent.intf_addr) == 0) {
-		syslog(LOG_DEBUG, __FUNCTION__ ": %s at %s",
+		syslog(LOG_DEBUG, "%s: %s at %s", __FUNCTION__,
 		    addr_ntoa(addr), addr_ntoa(&arpd_ifent.intf_link_addr));
 		return (0);
 	}
@@ -291,10 +295,10 @@ arpd_lookup(struct addr *addr)
 	error = arp_get(arpd_arp, &arpent);
 	
 	if (error == -1) {
-		syslog(LOG_DEBUG, __FUNCTION__ ": no entry for %s",
+		syslog(LOG_DEBUG, "%s: no entry for %s", __FUNCTION__,
 		    addr_ntoa(addr));
 	} else {
-		syslog(LOG_DEBUG, __FUNCTION__ ": %s at %s",
+		syslog(LOG_DEBUG, "%s: %s at %s", __FUNCTION__,
 		    addr_ntoa(addr), addr_ntoa(&arpent.arp_ha));
 	}
 	return (error);
@@ -423,7 +427,7 @@ arpd_recv_cb(u_char *u, const struct pca
 		if ((req = SPLAY_FIND(tree, &arpd_reqs, &tmp)) != NULL) {
 			addr_pack(&src.arp_ha, ADDR_TYPE_ETH, ETH_ADDR_BITS,
 			    ethip->ar_sha, ETH_ADDR_LEN);
-			syslog(LOG_DEBUG, __FUNCTION__ ": %s at %s",
+			syslog(LOG_DEBUG, "%s: %s at %s", __FUNCTION__,
 			    addr_ntoa(&req->pa), addr_ntoa(&src.arp_ha));
 			
 			/* This address is claimed */
@@ -445,9 +449,6 @@ arpd_recv(int fd, short type, void *ev)
 void
 terminate_handler(int sig)
 {
-	extern int event_gotsig;
-
-	event_gotsig = 1;
 	arpd_sig = sig;
 }
 
@@ -464,15 +465,14 @@ int
 main(int argc, char *argv[])
 {
 	struct event recv_ev;
-	extern int (*event_sigcb)(void);
-	char *dev;
+	char *dev, *and_pcap_exp;
 	int c, debug;
 	FILE *fp;
 
 	dev = NULL;
 	debug = 0;
 	
-	while ((c = getopt(argc, argv, "di:h?")) != -1) {
+	while ((c = getopt(argc, argv, "a:di:h?")) != -1) {
 		switch (c) {
 		case 'd':
 			debug = 1;
@@ -480,6 +480,9 @@ main(int argc, char *argv[])
 		case 'i':
 			dev = optarg;
 			break;
+		case 'a':
+			and_pcap_exp = optarg;
+			break;
 		default:
 			usage();
 			break;
@@ -489,9 +492,9 @@ main(int argc, char *argv[])
 	argv += optind;
 
 	if (argc == 0)
-		arpd_init(dev, 0, NULL);
+		arpd_init(dev, and_pcap_exp, 0, NULL);
 	else
-		arpd_init(dev, argc, argv);
+		arpd_init(dev, and_pcap_exp, argc, argv);
 	
 	if ((fp = fopen(PIDFILE, "w")) == NULL)
 		err(1, "fopen");
@@ -524,7 +527,6 @@ main(int argc, char *argv[])
 		perror("signal");
 		return (-1);
 	}
-	event_sigcb = arpd_signal;
 	
 	event_dispatch();
 
