Changeset 2924

Timestamp:

Aug 26, 2007, 4:44:27 PM (15 years ago)

Author:

joshe

Message:

Merge r2769 from trunk:

Use macros instead of magic numbers when creating and parsing handshake.
Make it trivial to disable extended messaging or azureus protocol at compile-time, for debugging.

Location:

branches/0.8x/libtransmission

Files:

• peer.c (modified) (2 diffs)
• peerparse.h (modified) (11 diffs)

branches/0.8x/libtransmission/peer.c

@@ -106 +106 @@
                                       than PEX_INTERVAL +
                                       rand( PEX_INTERVAL / 10 ) seconds */
-#define PEER_SUPPORTS_EXTENDED_MESSAGES( bits ) ( (bits)[5] & 0x10 )
-#define PEER_SUPPORTS_AZUREUS_PROTOCOL( bits )  ( (bits)[0] & 0x80 )
+
+/* uncomment this to disable support for the extended messaging bit */
+/* #define DISABLE_EXTMSGS */
+/* uncomment this to disable support for the azureus protocol bit */
+/* #define DISABLE_AZPROTO */
+
+#define HANDSHAKE_NAME          "\023BitTorrent protocol"
+#define HANDSHAKE_NAME_LEN      20
+#define HANDSHAKE_FLAGS_OFF     HANDSHAKE_NAME_LEN
+#define HANDSHAKE_FLAGS_LEN     8
+#define HANDSHAKE_HASH_OFF      ( HANDSHAKE_FLAGS_OFF + HANDSHAKE_FLAGS_LEN )
+#define HANDSHAKE_PEERID_OFF    ( HANDSHAKE_HASH_OFF + SHA_DIGEST_LENGTH )
+#define HANDSHAKE_SIZE          ( HANDSHAKE_PEERID_OFF + TR_ID_LEN )
+
+#ifdef DISABLE_EXTMSGS
+#define HANDSHAKE_HAS_EXTMSGS( bits ) ( 0 )
+#define HANDSHAKE_SET_EXTMSGS( bits ) ( (void)0 )
+#else
+#define HANDSHAKE_HAS_EXTMSGS( bits ) ( (bits)[5] & 0x10 )
+#define HANDSHAKE_SET_EXTMSGS( bits ) ( (bits)[5] |= 0x10 )
+#endif
+
+#ifdef DISABLE_AZPROTO
+#define HANDSHAKE_HAS_AZPROTO( bits ) ( 0 )
+#define HANDSHAKE_SET_AZPROTO( bits ) ( (void)0 )
+#else
+#define HANDSHAKE_HAS_AZPROTO( bits ) ( (bits)[0] & 0x80 )
+#define HANDSHAKE_SET_AZPROTO( bits ) ( (bits)[0] |= 0x80 )
+#endif
 
 #define PEER_MSG_CHOKE          0
@@ -523 +550 @@
     if( PEER_STATUS_CONNECTING == peer->status )
     {
-        uint8_t buf[68];
-        tr_info_t * inf = &tor->info;
-
-        buf[0] = 19;
-        memcpy( &buf[1], "BitTorrent protocol", 19 );
-        memset( &buf[20], 0, 8 );
-        buf[20] = 0x80;         /* azureus protocol */
-        buf[25] = 0x10;         /* extended messages */
-        memcpy( &buf[28], inf->hash, 20 );
-        memcpy( &buf[48], tor->peer_id, 20 );
+        uint8_t buf[HANDSHAKE_SIZE];
+        const tr_info_t * inf;
+
+        inf = tr_torrentInfo( tor );
+        assert( 68 == HANDSHAKE_SIZE );
+        memcpy( buf, HANDSHAKE_NAME, HANDSHAKE_NAME_LEN );
+        memset( buf + HANDSHAKE_FLAGS_OFF, 0, HANDSHAKE_FLAGS_LEN );
+        HANDSHAKE_SET_EXTMSGS( buf + HANDSHAKE_FLAGS_OFF );
+        HANDSHAKE_SET_AZPROTO( buf + HANDSHAKE_FLAGS_OFF );
+        memcpy( buf + HANDSHAKE_HASH_OFF, inf->hash, SHA_DIGEST_LENGTH );
+        memcpy( buf + HANDSHAKE_PEERID_OFF, tor->peer_id, TR_ID_LEN );
 
         switch( tr_netSend( peer->socket, buf, 68 ) )
         {
-            case 68:
+            case HANDSHAKE_SIZE:
                 peer_dbg( "SEND handshake" );
                 peer->status = PEER_STATUS_HANDSHAKE;

branches/0.8x/libtransmission/peerparse.h

@@ -564 +564 @@
     }
 
-    if( p[0] != 19 || memcmp( &p[1], "Bit", 3 ) )
+    if( 0 != memcmp( p, HANDSHAKE_NAME, 4 ) )
     {
         /* Don't wait until we get 68 bytes, this is wrong
@@ -576 +576 @@
         return TR_ERROR;
     }
-    if( peer->pos < 68 )
+    if( HANDSHAKE_SIZE > peer->pos )
     {
         return TR_OK;
     }
-    if( memcmp( &p[4], "Torrent protocol", 16 ) )
+    if( 0 != memcmp( peer->buf, HANDSHAKE_NAME, HANDSHAKE_NAME_LEN ) )
     {
         peer_dbg( "GET  handshake, invalid" );
@@ -591 +591 @@
 static const uint8_t * parseBufHash( const tr_peer_t * peer )
 {
-    if( 48 > peer->pos )
+    if( HANDSHAKE_HASH_OFF + SHA_DIGEST_LENGTH > peer->pos )
     {
         return NULL;
@@ -597 +597 @@
     else
     {
-        return peer->buf + 28;
+        return peer->buf + HANDSHAKE_HASH_OFF;
     }
 }
@@ -606 +606 @@
     int         ii;
 
-    if( memcmp( &peer->buf[28], inf->hash, SHA_DIGEST_LENGTH ) )
+    if( 0 != memcmp( peer->buf + HANDSHAKE_HASH_OFF, inf->hash,
+                     SHA_DIGEST_LENGTH ) )
     {
         peer_dbg( "GET  handshake, wrong torrent hash" );
@@ -612 +613 @@
     }
 
-    if( !memcmp( &peer->buf[48], tor->peer_id, TR_ID_LEN ) )
+    if( 0 == memcmp( peer->buf + HANDSHAKE_PEERID_OFF, tor->peer_id,
+                     TR_ID_LEN ) )
     {
         /* We are connected to ourselves... */
@@ -619 +621 @@
     }
 
-    memcpy( peer->id, &peer->buf[48], TR_ID_LEN );
+    memcpy( peer->id, peer->buf + HANDSHAKE_PEERID_OFF, TR_ID_LEN );
 
     for( ii = 0; ii < tor->peerCount; ii++ )
@@ -634 +636 @@
     }
 
-    if( PEER_SUPPORTS_EXTENDED_MESSAGES( &peer->buf[20] ) )
+    if( HANDSHAKE_HAS_EXTMSGS( peer->buf + HANDSHAKE_FLAGS_OFF ) )
     {
         peer->status = PEER_STATUS_CONNECTED;
@@ -641 +643 @@
                   tr_peerClient( peer ) );
     }
-    else if( PEER_SUPPORTS_AZUREUS_PROTOCOL( &peer->buf[20] ) )
+    else if( HANDSHAKE_HAS_AZPROTO( peer->buf + HANDSHAKE_FLAGS_OFF ) )
     {
         peer->status  = PEER_STATUS_AZ_GIVER;
@@ -703 +705 @@
             }
 
-            if( peer->pos < 68 )
+            if( HANDSHAKE_SIZE > peer->pos )
             {
                 break;
@@ -713 +715 @@
                 return ret;
             }
-            buf       += 68;
-            peer->pos -= 68;
+            buf       += HANDSHAKE_SIZE;
+            peer->pos -= HANDSHAKE_SIZE;
 
             ret = sendInitial( tor, peer );