From 940cbed1794737886f8f459d5ff62012ec64d248 Mon Sep 17 00:00:00 2001
From: David Schweikert <david@schweikert.ch>
Date: Wed, 25 Apr 2012 23:24:37 +0200
Subject: [PATCH] Added -H option to specify number of hops (Paul Duda)

---
 ChangeLog   |  1 +
 doc/fping.8 |  2 ++
 src/fping.c | 21 ++++++++++++++++++++-
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 1f4b9f0..76d5f80 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,7 @@ David Schweikert <david@schweikert.ch>
   * Reorganized source directory
   * Bugfix: fix timeout issue on Solaris (Sandor Geller)
   * Man-page fixes (Axel Beckert)
+  * Added -H option to specify number of hops (Paul Duda)
 
 Thu Dec 28 2011
 David Schweikert <david@schweikert.ch>
diff --git a/doc/fping.8 b/doc/fping.8
index 09a0fb1..f4c504f 100644
--- a/doc/fping.8
+++ b/doc/fping.8
@@ -145,6 +145,8 @@ Set the typ of service flag (TOS). \fIn\fR can be either decimal or hexadecimal
 Print
 .B fping
 version information.
+.IP \fB-H\fIn\fR 5
+Set the IP TTL field (time to live hops).
 
 .SH EXAMPLES
 The following perl script will check a list of hosts and send mail if
diff --git a/src/fping.c b/src/fping.c
index a898249..ed4d767 100644
--- a/src/fping.c
+++ b/src/fping.c
@@ -274,6 +274,7 @@ unsigned int ping_pkt_size;
 unsigned int count = 1;
 unsigned int trials;
 unsigned int report_interval = 0;
+unsigned int ttl = 0;
 int src_addr_present = 0;
 #ifndef IPV6
 struct in_addr src_addr;
@@ -489,7 +490,7 @@ int main( int argc, char **argv )
 
     /* get command line options */
 
-    while( ( c = getopt( argc, argv, "gedhlmnqusaAvz:t:i:p:f:r:c:b:C:Q:B:S:I:T:O:" ) ) != EOF )
+    while( ( c = getopt( argc, argv, "gedhlmnqusaAvz:t:H:i:p:f:r:c:b:C:Q:B:S:I:T:O:" ) ) != EOF )
     {
         switch( c )
         {
@@ -593,6 +594,11 @@ int main( int argc, char **argv )
             alive_flag = 1;
             break;
 
+        case 'H':  
+            if( !( ttl = ( u_int )atoi( optarg ) ))
+                usage();
+            break;  
+
 #if defined( DEBUG ) || defined( _DEBUG )
         case 'z':
             if( ! ( debugging = ( unsigned int )atoi( optarg ) ) )
@@ -676,6 +682,11 @@ int main( int argc, char **argv )
 
     /* validate various option settings */
 
+    if (ttl < 0 || ttl > 255) {  
+        fprintf(stderr, "ping: ttl %u out of range\n", ttl);  
+        usage();
+    }  
+
     if( unreachable_flag && alive_flag )
     {
         fprintf( stderr, "%s: specify only one of a, u\n", argv[0] );
@@ -808,6 +819,13 @@ int main( int argc, char **argv )
     }/* IF */
 #endif /* DEBUG || _DEBUG */
 
+    /* set the TTL, if the -H option was set (otherwise ttl will be = 0) */
+    if(ttl > 0) {
+        if (setsockopt(s, IPPROTO_IP, IP_TTL,  &ttl, sizeof(ttl))) {
+            perror("setting time to live");
+        }
+    }
+
     /* handle host names supplied on command line or in a file */
     /* if the generate_flag is on, then generate the IP list */
 
@@ -2795,6 +2813,7 @@ void usage( void )
     fprintf( stderr, "   -g         generate target list (only if no -f specified)\n" );
     fprintf( stderr, "                (specify the start and end IP in the target list, or supply a IP netmask)\n" );
         fprintf( stderr, "                (ex. %s -g 192.168.1.0 192.168.1.255 or %s -g 192.168.1.0/24)\n", prog, prog );
+    fprintf( stderr, "   -H n       Set the IP TTL value (Time To Live hops)\n");
     fprintf( stderr, "   -i n       interval between sending ping packets (in millisec) (default %d)\n", interval / 100 );
     fprintf( stderr, "   -l         loop sending pings forever\n" );
     fprintf( stderr, "   -m         ping multiple interfaces on target host\n" );