Re: Binding an IOC to a single network interface

["J. Lewis Muir" <jlmuir@imca-cat.org>]

On 1/22/14 8:30 AM, freddie.akeroyd@stfc.ac.uk wrote:
> Hi,
> 
> we are looking to run a set of IOCs that bind channel access to just
> the loopback interface on the computer; however I saw from the 3.14
> docs that EPICS_CAS_INTF_ADDR_LIST is not currently implemented in the
> iocCore CA Server. I had a look at the code in base/src/rsrv and the
> attached diff (against 3.14.12.2) seems to work for us with:
> 
> EPICS_CAS_INTF_ADDR_LIST=127.0.0.1
> EPICS_CAS_BEACON_ADDR_LIST=127.255.255.255

Below is an adaptation of the patch for caRepeater to let it play too.

I'm unclear on whether caRepeater is considered part of CAS.  It
gets started by the IOC automatically if it's not already running,
so I considered it part of CAS.  Hence, it uses the same environment
variable.  But if it's not considered part of CAS, then I guess it
should get its own environment variable.

Andrew, I don't think you've committed Freddie's patch to the 3.15 tree,
so I'm just posting this additional patch in the hope that it could go
in with Freddie's patch when you get around to it.

Thanks!

Lewis

--- src/ca/repeater.cpp.orig	2013-12-16 15:56:27.000000000 -0600
+++ src/ca/repeater.cpp	2014-10-03 17:12:12.000000000 -0500
@@ -115,6 +115,7 @@
 		struct sockaddr_in ia;
 		struct sockaddr sa;
 	} bd;
+    const char* pStr;
 
     SOCKET sock = epicsSocketCreate ( AF_INET, SOCK_DGRAM, 0 );     
     if ( sock == INVALID_SOCKET ) {
@@ -128,8 +129,19 @@
 
         memset ( (char *) &bd, 0, sizeof (bd) );
         bd.ia.sin_family = AF_INET;
-        bd.ia.sin_addr.s_addr = htonl ( INADDR_ANY ); 
-        bd.ia.sin_port = htons ( port );  
+        pStr = envGetConfigParamPtr ( & EPICS_CAS_INTF_ADDR_LIST );
+        if (pStr) {
+            /* this implementation only allows for specifying a single address in EPICS_CAS_INTF_ADDR_LIST */
+            status = aToIPAddr ( pStr, port, &bd.ia );
+            if (status) {
+                fprintf( stderr, "CA Repeater: error parsing %s '%s'\n", EPICS_CAS_INTF_ADDR_LIST.name, pStr );
+                bd.ia.sin_addr.s_addr = htonl ( INADDR_ANY );
+                bd.ia.sin_port = htons ( port );
+            }
+        } else {
+            bd.ia.sin_addr.s_addr = htonl ( INADDR_ANY );
+            bd.ia.sin_port = htons ( port );
+        }
         status = bind ( sock, &bd.sa, (int) sizeof(bd) );
         if ( status < 0 ) {
             epicsSocketDestroy ( sock );