work around libnet bug: never call libnet_init() with ifname=NULL.

Thanks Pavol Babincak <scroolik@gmail.com>

2 files changed, 57 insertions, 45 deletions

diff --git a/arping-2/arping.c b/arping-2/arping.c
index a9326f6..5d97382 100644
--- a/arping-2/arping.c
+++ b/arping-2/arping.c
@@ -12,7 +12,7 @@
  *
  * Also finds out IP of specified MAC
  *
- * $Id: arping.c 1972 2007-09-19 12:35:16Z marvin $
+ * $Id: arping.c 2040 2008-02-04 13:03:47Z marvin $
  */
 /*
  *  Copyright (C) 2000-2002 Thomas Habets <thomas@habets.pp.se>
@@ -151,8 +151,10 @@ static void do_libnet_init(const char *ifname)
 /*
  *
  */
-static const char *arping_lookupdev_default(u_int32_t srcip, u_int32_t dstip,
-				     char *ebuf)
+static const char *
+arping_lookupdev_default(const char *ifname,
+			 u_int32_t srcip, u_int32_t dstip,
+			 char *ebuf)
 {
 #ifdef WIN32
 	WCHAR buf[LIBNET_ERRBUF_SIZE + PCAP_ERRBUF_SIZE];
@@ -171,7 +173,9 @@ static const char *arping_lookupdev_default(u_int32_t srcip, u_int32_t dstip,
 /*
  *
  */
-static const char *arping_lookupdev(u_int32_t srcip, u_int32_t dstip,
+static const char *arping_lookupdev(const char *ifname,
+				    u_int32_t srcip,
+				    u_int32_t dstip,
 				    char *ebuf)
 {
 	FILE *f;
@@ -181,7 +185,7 @@ static const char *arping_lookupdev(u_int32_t srcip, u_int32_t dstip,
 	char *p,*p2;
 	int n;
 
-	do_libnet_init(NULL);
+	do_libnet_init(ifname);
 	libnet_addr2name4_r(dstip,0,buf2);
 	libnet_addr2name4_r(srcip,0,buf1);
 
@@ -220,12 +224,13 @@ static const char *arping_lookupdev(u_int32_t srcip, u_int32_t dstip,
 	*p2 = 0;
 	return p;
  failed:
-	return arping_lookupdev_default(srcip,dstip,ebuf);
+	return arping_lookupdev_default(ifname,srcip,dstip,ebuf);
 }
 #elif defined(FINDIF) && defined(HAVE_WEIRD_BSD)
 static
 const char *
-arping_lookupdev(u_int32_t srcip, u_int32_t dstip, char *ebuf)
+arping_lookupdev(const char *ifname,
+		 u_int32_t srcip, u_int32_t dstip, char *ebuf)
 {
 	FILE *f;
 	static char buf[10240];
@@ -233,7 +238,7 @@ arping_lookupdev(u_int32_t srcip, u_int32_t dstip, char *ebuf)
 	char *p,*p2;
 	int n;
 
-	do_libnet_init(NULL);
+	do_libnet_init(ifname);
 	libnet_addr2name4_r(dstip,0,buf1);
 	//libnet_addr2name4_r(srcip,0,buf1);
 
@@ -278,10 +283,11 @@ arping_lookupdev(u_int32_t srcip, u_int32_t dstip, char *ebuf)
 /*
  *
  */
-static const char *arping_lookupdev(u_int32_t srcip, u_int32_t dstip,
+static const char *arping_lookupdev(const char *ifname,
+				    u_int32_t srcip, u_int32_t dstip,
 				    char *ebuf)
 {
-	return arping_lookupdev_default(srcip,dstip,ebuf);
+	return arping_lookupdev_default(ifname,srcip,dstip,ebuf);
 }
 #endif
 
@@ -1042,7 +1048,7 @@ int main(int argc, char **argv)
 			break;
 		}
 		case 'S': // set source IP, may be null for don't-know
-			do_libnet_init(NULL);
+			do_libnet_init(ifname);
 			if (-1 == (srcip = libnet_name2addr4(libnet,
 							     optarg,
 							     LIBNET_RESOLVE))){
@@ -1079,7 +1085,7 @@ int main(int argc, char **argv)
 					"in MAC ping mode\n");
 				exit(1);
 			}
-			do_libnet_init(NULL);
+			do_libnet_init(ifname);
 			if (-1 == (dstip = libnet_name2addr4(libnet,
 							     optarg,
 							     LIBNET_RESOLVE))){
@@ -1114,7 +1120,7 @@ int main(int argc, char **argv)
 			mode = is_mac_addr(parm)?PINGMAC:PINGIP;
 		} else if (dstip_given) {
 			mode = PINGIP;
-			do_libnet_init(NULL);
+			do_libnet_init(ifname);
 			parm = strdup(libnet_addr2name4(dstip,0));
 			if (!parm) {
 				fprintf(stderr, "arping: out of mem\n");
@@ -1194,9 +1200,10 @@ int main(int argc, char **argv)
 	 */
 	if (!ifname) {
 		if (dont_use_arping_lookupdev) {
-			ifname = arping_lookupdev_default(srcip,dstip,ebuf);
+			ifname = arping_lookupdev_default(ifname,
+							  srcip,dstip,ebuf);
 		} else {
-			ifname = arping_lookupdev(srcip,dstip,ebuf);
+			ifname = arping_lookupdev(ifname,srcip,dstip,ebuf);
 		}
 		if (!ifname) {
 			fprintf(stderr, "arping: arping_lookupdev(): %s\n",
diff --git a/arping.8 b/arping.8
index dae27ff..122950f 100644
--- a/arping.8
+++ b/arping.8
@@ -1,12 +1,13 @@
-.TH "arping" "8" "21th June, 2003" "arping" "" 
+.TH "arping" "8" "21th June, 2003" "arping" ""
+
 .PP 
-.SH "NAME" 
+.SH "NAME"
 arping \- sends arp and/or ip pings to a given host
 .PP 
-.SH "SYNOPSIS" 
+.SH "SYNOPSIS"
 \fBarping\fP [-abhpqrRd0uv] [-S \fIhost/ip\fP] [-T \fIhost/ip\fP] [-s \fIMAC\fP]    [-t \fIMAC\fP] [-c \fIcount\fP] [-i \fIinterface\fP] [ -w \fIus\fP ] <\fIhost\fP | -B>
 .PP 
-.SH "DESCRIPTION" 
+.SH "DESCRIPTION"
 The \fIarping\fP utility sends \fBARP\fP and/or \fBICMP\fP requests to the specified \fIhost\fP and displays the replies\&. The \fIhost\fP may be specified by its \fBhostname\fP, its \fBIP\fP address, or its \fBMAC\fP address\&.
 .PP 
 One request is sent each second\&.
@@ -31,81 +32,85 @@ This is not just an issue with arping, it is with normal ping also
 since arping packets (when pinging IP) doesn\&'t traverse the IP stack when
 received and are therefore replied to faster\&.
 .PP 
-.SH "OPTIONS" 
+.SH "OPTIONS"
+
 .PP 
-.IP 
-.IP "-0" 
+.IP "-0"
 Use this option to ping with source IP address 0\&.0\&.0\&.0\&. Use this
 when you haven\&'t configured your interface yet\&.
 Note that this may get the MAC-ping unanswered\&.
 This is an alias for -S 0\&.0\&.0\&.0\&.
-.IP "-a" 
+.IP "-a"
 Audible ping\&.
-.IP "-A" 
+.IP "-A"
 Only count addresses matching requested address (This *WILL*
 break most things you do\&. Only useful if you are arpinging many
 hosts at once\&. See arping-scan-net\&.sh for an example)\&.
-.IP "-b" 
+.IP "-b"
 Like -0 but source broadcast source address (255\&.255\&.255\&.255)\&.
 Note that this may get the arping unanswered since it\&'s not normal behavior
 for a host\&.
-.IP "-B" 
+.IP "-B"
 Use instead of host if you want to address 255\&.255\&.255\&.255\&.
-.IP "-c \fIcount\fP" 
+.IP "-c \fIcount\fP"
 Only send \fIcount\fP requests\&.
-.IP "-d" 
+.IP "-d"
 Find duplicate replies\&.
-.IP "-F" 
+.IP "-F"
 Don\&'t try to be smart about the interface name\&. (even if this
 switch is not given, -i overrides smartness\&.
-.IP "-h" 
+.IP "-h"
 Displays a help message and exits\&.
-.IP "-i \fIinterface\fP" 
+.IP "-i \fIinterface\fP"
 Use the specified interface\&.
-.IP "-q" 
+.IP "-q"
 Does not display messages, except error messages\&.
-.IP "-r" 
+.IP "-r"
 Raw output: only the MAC/IP address is displayed for each reply\&.
-.IP "-R" 
+.IP "-R"
 Raw output: Like -r but shows "the other one", can be combined with
 -r\&.
-.IP "-s \fIMAC\fP" 
+.IP "-s \fIMAC\fP"
 Set source MAC address\&. You may need to use -p with this\&.
-.IP "-S \fIIP\fP" 
+.IP "-S \fIIP\fP"
 Like -b and -0 but with set source address\&.
 Note that this may get the arping unanswered if the target does not have
 routing to the IP\&. If you don\&'t own the IP you are using, you may need to turn
 on promiscious mode on the interface (with -p)\&. With this switch you can find
 out what IP-address a host has without taking an IP-address yourself\&.
-.IP "-t \fIMAC\fP" 
+.IP "-t \fIMAC\fP"
 Set target MAC address to use when pinging IP address\&.
-.IP "-T \fIIP\fP" 
+.IP "-T \fIIP\fP"
 Use -T as target address when pinging MACs that won\&'t
 respond to a broadcast ping but perhaps to a directed broadcast\&.
 .IP 
 \fIExample\fP:                                                                To check the address of MAC-A, use knowledge of MAC-B and IP-B\&.
 .IP 
 $ arping -S <IP-B> -s <MAC-B> -p <MAC-A>
-.IP "-p" 
+.IP "-p"
 Turn on promiscious mode on interface, use this if you don\&'t
 "own" the MAC address you are using\&.
-.IP "-u" 
+.IP "-u"
 Show index=received/sent instead of just index=received when
 pinging MACs\&.
-.IP "-v" 
+.IP "-v"
 Verbose output\&. Use twice for more messages\&.
-.IP "-w" 
+.IP "-w"
 (arping 2\&.x only) Time to wait between pings, in microseconds\&.
+
 .PP 
-.SH "BUGS" 
+.SH "BUGS"
+
 .PP 
 You have to use -B instead of arpinging 255\&.255\&.255\&.255, and -b
 instead of -S 255\&.255\&.255\&.255\&. This is libnets fault\&.
 .PP 
-.SH "SEE ALSO" 
+.SH "SEE ALSO"
+
 .PP 
 \fBping(8)\fP, \fBarp(8)\fP, \fBrarp(8)\fP
 .PP 
-.SH "AUTHOR" 
+.SH "AUTHOR"
+
 .PP 
 Arping was written by Thomas Habets <thomas@habets\&.pp\&.se>\&.