[ net-snmp-Bugs-416836 ] snmptrapd-not listening on specified I/F

[<no...@so...>]

Bugs item #416836, was opened at 2001-04-17 14:00
You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=112694&aid=416836&group_id=12694

Category: apps
Group: None
Status: Closed
Resolution: Wont Fix
Priority: 1
Submitted By: Nobody/Anonymous (nobody)
Assigned to: John Naylon (jbpn)
Summary: snmptrapd-not listening on specified I/F

Initial Comment:
UCD-snmp version: 4.2.1
compiled from source for
RedHat 6.2 with kernel 2.2.17-14.1s6
on an i686

----------------

starting snmptrapd with -p option does not appear to
limit interfaces on which it listens.

If I execute
snmpd -p 16...@my...s
netstat (and a walk of the udp table) shows snmpd only
listening on that i/f

If I execute
snmptrapd -p 16...@my...s
netstat (and a walk of the udp table) shows snmptrapd
listening on all interfaces.

david

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Comment By: Zing Shishak (shishz)
Date: 2001-07-30 08:23

Message:
Logged In: YES 
user_id=284784

hacked in -i <ip addr>... had to do this recently.  yechh.

--- ucd-snmp-4.2.1/apps/snmptrapd.c.orig	Mon Jul 30 10:06:40
2001
+++ ucd-snmp-4.2.1/apps/snmptrapd.c	Mon Jul 30 10:50:54 2001
@@ -657,6 +657,7 @@
     int count, numfds, block;
     fd_set fdset;
     struct timeval timeout, *tvp;
+    char local_ip[80] = "\0";
     int local_port = SNMP_TRAP_PORT;
     int dofork=1;
     char *cp;
@@ -702,7 +703,7 @@
     /*
      * usage: snmptrapd [-D] [-u PIDFILE] [-p #] [-P] [-s]
[-l [d0-7]] [-d] [-e] [-a]
      */
-    while ((arg = getopt(argc, argv,
"VdnqRD:p:m:M:Po:O:esSafl:Hu:c:CF:T:")) != EOF){
+    while ((arg = getopt(argc, argv,
"VdnqRD:i:p:m:M:Po:O:esSafl:Hu:c:CF:T:")) != EOF){
 	switch(arg) {
 	case 'V':
             fprintf(stderr,"UCD-snmp version: %s\n",
VersionInfo);
@@ -718,6 +719,10 @@
             debug_register_tokens(optarg);
             snmp_set_do_debugging(1);
 	    break;
+	case 'i':
+	    local_ip[80]='\0';
+	    strncpy(local_ip, optarg,79);
+	    break;
         case 'p':
             local_port = atoi(optarg);
             break;
@@ -908,7 +913,14 @@
 
 
     snmp_sess_init(session);
-    session->peername = SNMP_DEFAULT_PEERNAME; /* Original
code had NULL here */
+
+    /* hack in support for binding to specific interface
(-i <ip addr>) */
+    if (strlen(local_ip)) {
+      session->peername = malloc(strlen(local_ip));
+      strcpy(session->peername, local_ip);
+    }
+    else
+      session->peername = SNMP_DEFAULT_PEERNAME; /*
Original code had NULL here */
     session->version = SNMP_DEFAULT_VERSION;
 
     session->community_len = SNMP_DEFAULT_COMMUNITY_LEN;


----------------------------------------------------------------------

Comment By: John Naylon (jbpn)
Date: 2001-04-18 02:52

Message:
Logged In: YES 
user_id=93926

Binding to a specific interface is not currently supported
by snmptrapd, only snmpd.  I know this seems inconsistent,
but I don't believe it is claimed anywhere that snmptrapd
does support binding to a specific interface.

It would be pretty easy to hack this to make it work if you
need to (see snmptrapd.c).  "Unified transport endpoint
specifier handling" is a work item for 5.0, and how it works
will likely completely change, so I don't propose to put any
effort into a "quick fix" now.  Of course if someone else
wants to...

----------------------------------------------------------------------

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