From 1acd9e02243625ab1aff4d8ca4ffd6daab1ea84e Mon Sep 17 00:00:00 2001
From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Sat, 12 Nov 2022 10:30:26 +1100
Subject: [PATCH] limiting dest IP capture to donwlinks

---
 rrqnet.c | 70 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/rrqnet.c b/rrqnet.c
index 7c70220..193e673 100644
--- a/rrqnet.c
+++ b/rrqnet.c
@@ -1086,9 +1086,11 @@ static void unmap_if_mapped(struct SockAddr *s) {
 }
 
 // Route the packet from the given src
-static struct Interface *input_check(
-    unsigned char *buf,ssize_t len,struct SockAddr *src )
-{
+static struct Interface *input_check(PacketItem *pi) {
+    unsigned char *buf = pi->buffer;
+    ssize_t len = pi->len;
+    struct SockAddr *src = &pi->src;
+
     VERBOSE2OUT( "RECV %ld bytes from %s\n", len, inet_stoa( src ) );
     struct Remote *r = 0;
     struct timeval now = { 0 };
@@ -1106,6 +1108,24 @@ static struct Interface *input_check(
 	VERBOSEOUT( "New remote %s by %s\n", inet_stoa( src ), a->source );
 	r = add_remote( src, a );
 	//r->rec_when = now; // Set activity stamp of new remote
+	// Set the local addressing for the remote, unless set already
+	// Note: potential for multi-thread competition here
+	if ( udp6 ) {
+	    r->ifindex = pi->dstinfo.in6.ipi6_ifindex;
+	    r->laddr.in6.sin6_family = AF_INET6;
+	    r->laddr.in6.sin6_port = htons( udp_port );
+	    memcpy( &r->laddr.in6.sin6_addr,
+		    &pi->dstinfo.in6.ipi6_addr,
+		    16 );
+	    unmap_if_mapped( &r->laddr );
+	} else {
+	    r->ifindex = pi->dstinfo.in4.ipi_ifindex;
+	    r->laddr.in4.sin_family = AF_INET;
+	    r->laddr.in4.sin_port = htons( udp_port );
+	    memcpy( &r->laddr.in4.sin_addr,
+		    &pi->dstinfo.in4.ipi_spec_dst,
+		    4 );
+	}
     }
     if ( len < 12 ) {
 	// Ignore short data, but maintain channel
@@ -1208,55 +1228,35 @@ static struct Interface *input_check(
 
 // Check packet and deliver out
 static void route_packet(PacketItem *pi) {
-    unsigned char *buf = pi->buffer;
-    int len = pi->len;
-    struct SockAddr *src = &pi->src;
-    struct Interface *x = input_check( buf, len, src );
+    //unsigned char *buf = pi->buffer;
+    //ssize_t len = pi->len;
+    struct Interface *x = input_check( pi );
     if ( x == 0 ) {
 	VERBOSE2OUT( "not a nice packet\n" );
 	return; // not a nice packet
     }
-    // Set the local addressing for the remote, unless set already
-    if ( x->remote->ifindex == 0 ) {
-	if ( udp6 ) {
-	    x->remote->ifindex = pi->dstinfo.in6.ipi6_ifindex;
-	    x->remote->laddr.in6.sin6_family = AF_INET6;
-	    x->remote->laddr.in6.sin6_port = htons( udp_port );
-	    memcpy( &x->remote->laddr.in6.sin6_addr,
-		    &pi->dstinfo.in6.ipi6_addr,
-		    16 );
-	    unmap_if_mapped( &x->remote->laddr );
-	} else {
-	    x->remote->ifindex = pi->dstinfo.in4.ipi_ifindex;
-	    x->remote->laddr.in4.sin_family = AF_INET;
-	    x->remote->laddr.in4.sin_port = htons( udp_port );
-	    memcpy( &x->remote->laddr.in4.sin_addr,
-		    &pi->dstinfo.in4.ipi_spec_dst,
-		    4 );
-	}
-    }
-    if ( ( *buf & 1 ) == 0 ) {
+    if ( ( *pi->buffer & 1 ) == 0 ) {
 	// unicast
 	struct Interface *y = 0; // reuse for destination interface
-	Interface_FIND( buf, y );
+	Interface_FIND( pi->buffer, y );
 	if ( y == 0 ) {
 	    VERBOSE2OUT( "RECV %s -> %s from %s without channel and dropped\n",
-			inet_mtoa( buf+6 ), inet_mtoa( buf ),
+			inet_mtoa( pi->buffer + 6 ), inet_mtoa( pi->buffer ),
 			inet_stoa( &x->remote->uaddr ) );
 	    return;
 	}
 	if ( x->remote == y->remote ) {
 	    VERBOSEOUT( "RECV loop for %s -> %s from %s to %s\n",
-			inet_mtoa( buf+6 ), inet_mtoa( buf ),
+			inet_mtoa( pi->buffer+6 ), inet_mtoa( pi->buffer ),
 			inet_stoa( &x->remote->uaddr ),
 			inet_stoa( &y->remote->uaddr ) );
 	    Interface_DEL( y ); // Need to see this interface again
 	    return;
 	}
 	VERBOSE2OUT( "RECV route %s -> %s\n",
-		     inet_mtoa( buf+6 ),
-		     inet_mtoa( buf ) );
-	write_remote( buf, len, y->remote );
+		     inet_mtoa( pi->buffer+6 ),
+		     inet_mtoa( pi->buffer ) );
+	write_remote( pi->buffer, pi->len, y->remote );
 	return;
     }
     // broadcast. +x+ is source interface
@@ -1267,7 +1267,7 @@ static void route_packet(PacketItem *pi) {
 	now.tv_sec = time( 0 );
     }
     VERBOSE2OUT( "BC %s -> %s from %s to %s\n",
-		 inet_mtoa( buf+6 ), inet_mtoa( buf ),
+		 inet_mtoa( pi->buffer+6 ), inet_mtoa( pi->buffer ),
 		 inet_stoa( &x->remote->uaddr ),
 		 inet_stoa( &x->remote->laddr ) );
     struct Remote *r;
@@ -1296,7 +1296,7 @@ static void route_packet(PacketItem *pi) {
 	}
 	// Send packet to the remote
 	// Only no-clash or to the tap/stdin
-	write_remote( buf, len, r );
+	write_remote( pi->buffer, pi->len, r );
     }
     Remote_UNLOCK;
 }
-- 
2.39.2