enhance(API): Add source IP support to msg header

[ric-plt/lib/rmr.git] / src / rmr / common / src / tools_static.c

diff --git a/src/rmr/common/src/tools_static.c b/src/rmr/common/src/tools_static.c
index 8e615af..67adc85 100644 (file)
--- a/src/rmr/common/src/tools_static.c
+++ b/src/rmr/common/src/tools_static.c
@@ -237,9 +237,12 @@ static int uta_has_str( char const* buf, char const* str, char sep, int max ) {
        that could be in the route table.
 
        If the environment variable which limits the binding of our listen port
-       to a single interface (ENV_BIND_IF) then ONLY that address is added to
-       the list so that we don't pick up entries from the rtable that are for other
+       to a single interface (ENV_BIND_IF) then ONLY that interface/address is added
+       to the list so that we don't pick up entries from the rtable that are for other
        processes listening on different interfaces.
+
+       The ENV_BIN_IF environment variable may be either an IP address (v6 must be in 
+       square braces), or an interface name (e.g. eth0).
 */
 if_addrs_t*  mk_ip_list( char* port ) {
        if_addrs_t* l;
@@ -249,7 +252,8 @@ if_addrs_t*  mk_ip_list( char* port ) {
        char    wbuf[NI_MAXHOST+128];
        char*   fmt;
        char*   envp;                           // at the environment var if there
-
+       char*   target_if = NULL;       // target interface supplied by ENV_BIND_IF
+       char*   tok;
 
 
        if( (l = (if_addrs_t *) malloc( sizeof( if_addrs_t ) )) == NULL ) {
@@ -263,18 +267,23 @@ if_addrs_t*  mk_ip_list( char* port ) {
        }
 
        if( (envp = getenv( ENV_BIND_IF )) != NULL ) {
-               snprintf( wbuf, sizeof( wbuf ), "%s:%s", envp, port );          // smash port onto the addr as is
-               l->addrs[l->naddrs] = strdup( wbuf );
-               l->naddrs++;
-               if( DEBUG ) fprintf( stderr, "[INFO] rmr: using only specific bind interface when searching specific RT entries: %s\n", wbuf );
-               return l;
+               if( isdigit( *envp ) || *envp == '[' ) {                                        // ip address given and not device name
+                       snprintf( wbuf, sizeof( wbuf ), "%s:%s", envp, port );          // smash port onto the addr as is
+                       l->addrs[l->naddrs] = strdup( wbuf );
+                       l->naddrs++;
+                       if( DEBUG ) fprintf( stderr, "[INFO] rmr: using only specific bind interface when searching specific RT entries: %s\n", wbuf );
+                       return l;
+               }
+
+               target_if = envp;               // device name given, suss it out below
        }
 
        getifaddrs( &ifs );
        for( ele = ifs; ele; ele = ele->ifa_next ) {
-               *octs = 0;
+               memset( octs, 0, sizeof( octs ) );
+               if( ele && strcmp( ele->ifa_name, "lo" ) &&                                                                     // do NOT capture the loopback interface address
+                       (target_if == NULL || strcmp( ele->ifa_name, target_if ) == 0 ) ) {             // no target, or matches ENV_BIND_IF target
 
-               if( ele && strcmp( ele->ifa_name, "lo" )  ) {
                        if( ele->ifa_addr->sa_family == AF_INET ) {
                                getnameinfo( ele->ifa_addr, sizeof( struct sockaddr_in ),  octs, NI_MAXHOST, NULL, 0, NI_NUMERICHOST );
                                fmt = "%s:%s";
@@ -286,7 +295,12 @@ if_addrs_t*  mk_ip_list( char* port ) {
                        }
 
                        if( *octs ) {
+                               if( (tok = strchr( octs, '%' )) != NULL ) {                     // for unknown reasons some ip6 addrs have %if-name appended; truncate
+                                       *tok = 0;
+                               }
                                if( l->naddrs < 128 ) {
+                                       if( DEBUG ) fprintf( stderr, "[DBUG] capture address: %s: %s\n", ele->ifa_name, octs );
+
                                        snprintf( wbuf, sizeof( wbuf ), fmt, octs, port );              // smash port onto the addr
                                        l->addrs[l->naddrs] = strdup( wbuf );
                                        l->naddrs++;
@@ -380,4 +394,21 @@ static int has_myip( char const* buf, if_addrs_t* list, char sep, int max ) {
        return rc;
 }
 
+/*
+       Given a list manager block, return the default IP address.
+       For now, that is just the first address on the list which
+       easily could be non-deterministic and change with each restart
+       of the application if a specific interface is not provided via
+       the environment variable (ENV_BIND_IF) and if there is more than
+       one device available on the container/physical host.
+*/
+static char* get_default_ip( if_addrs_t* iplist ) {
+
+       if( iplist != NULL  &&  iplist->naddrs > 0  &&  iplist->addrs != NULL ) {
+               return strdup( iplist->addrs[0] );
+       }
+
+       return NULL;
+}
+
 #endif