(trunk libT) Add an enumeration for the peer id length. Use that enum for the peer_id fields in tr_session and tr_torrent.

This also avoids an extra malloc/free per-torrent and per-session, but mostly this tweak is for the extra readability of the PEER_ID_LEN=20 enum.

libtransmission/handshake.c

@@ -50,7 +50,6 @@ enum
     HANDSHAKE_NAME_LEN             = 20,
     HANDSHAKE_FLAGS_LEN            = 8,
     HANDSHAKE_SIZE                 = 68,
-    PEER_ID_LEN                    = 20,
     INCOMING_HANDSHAKE_LEN         = 48,
 
     /* Encryption Constants */
@@ -218,7 +217,7 @@ buildHandshakeMessage( tr_handshake * handshake, uint8_t * buf )
     uint8_t          * walk = buf;
     const uint8_t    * torrentHash = tr_cryptoGetTorrentHash( handshake->crypto );
     const tr_torrent * tor = tr_torrentFindFromHash( handshake->session, torrentHash );
-    const uint8_t    * peer_id = tor && tor->peer_id ? tor->peer_id : tr_getPeerId( );
+    const uint8_t    * peer_id = tor ? tor->peer_id : tr_getPeerId( handshake->session );
 
     memcpy( walk, HANDSHAKE_NAME, HANDSHAKE_NAME_LEN );
     walk += HANDSHAKE_NAME_LEN;
@@ -298,7 +297,7 @@ parseHandshake( tr_handshake *    handshake,
     dbgmsg( handshake, "peer-id is [%*.*s]", PEER_ID_LEN, PEER_ID_LEN, peer_id );
 
     tor = tr_torrentFindFromHash( handshake->session, hash );
-    tor_peer_id = tor && tor->peer_id ? tor->peer_id : tr_getPeerId( );
+    tor_peer_id = tor ? tor->peer_id : tr_getPeerId( handshake->session );
     if( !memcmp( peer_id, tor_peer_id, PEER_ID_LEN ) )
     {
         dbgmsg( handshake, "streuth!  we've connected to ourselves." );
@@ -741,7 +740,7 @@ readPeerId( tr_handshake    * handshake,
 
     /* if we've somehow connected to ourselves, don't keep the connection */
     tor = tr_torrentFindFromHash( handshake->session, tr_peerIoGetTorrentHash( handshake->io ) );
-    tor_peer_id = tor && tor->peer_id ? tor->peer_id : tr_getPeerId( );
+    tor_peer_id = tor ? tor->peer_id : tr_getPeerId( handshake->session );
     peerIsGood = memcmp( peer_id, tor_peer_id, PEER_ID_LEN ) != 0;
     dbgmsg( handshake, "isPeerGood == %d", (int)peerIsGood );
     return tr_handshakeDone( handshake, peerIsGood );

libtransmission/session.c

@@ -81,13 +81,12 @@ getRandomPort( tr_session * s )
    characters, where x is the major version number, y is the
    minor version number, z is the maintenance number, and b
    designates beta (Azureus-style) */
-uint8_t*
-tr_peerIdNew( void )
+void
+tr_peerIdInit( uint8_t * buf )
 {
     int          i;
     int          val;
     int          total = 0;
-    uint8_t *    buf = tr_new( uint8_t, 21 );
     const char * pool = "0123456789abcdefghijklmnopqrstuvwxyz";
     const int    base = 36;
 
@@ -103,18 +102,6 @@ tr_peerIdNew( void )
     val = total % base ? base - ( total % base ) : 0;
     buf[19] = pool[val];
     buf[20] = '\0';
-
-    return buf;
-}
-
-const uint8_t*
-tr_getPeerId( void )
-{
-    static uint8_t * id = NULL;
-
-    if( id == NULL )
-        id = tr_peerIdNew( );
-    return id;
 }
 
 /***
@@ -580,6 +567,7 @@ tr_sessionInit( const char  * tag,
     session->tag = tr_strdup( tag );
     session->magicNumber = SESSION_MAGIC_NUMBER;
     session->buffer = tr_valloc( SESSION_BUFFER_SIZE );
+    tr_peerIdInit( session->peer_id );
     tr_bencInitList( &session->removedTorrents, 0 );
 
     /* nice to start logging at the very beginning */

libtransmission/session.h

@@ -33,9 +33,12 @@
 
 typedef enum { TR_NET_OK, TR_NET_ERROR, TR_NET_WAIT } tr_tristate_t;
 
-uint8_t*       tr_peerIdNew( void );
+enum
+{
+  PEER_ID_LEN = 20
+};
 
-const uint8_t* tr_getPeerId( void );
+void tr_peerIdInit( uint8_t * setme );
 
 struct event_base;
 struct tr_address;
@@ -206,6 +209,8 @@ struct tr_session
     tr_bool bufferInUse;
 
     tr_web_config_func          * curl_easy_config_func;
+
+    uint8_t peer_id[PEER_ID_LEN+1];
 };
 
 static inline tr_port
@@ -214,6 +219,12 @@ tr_sessionGetPublicPeerPort( const tr_session * session )
     return session->public_peer_port;
 }
 
+static inline const uint8_t*
+tr_getPeerId( tr_session * session )
+{
+    return session->peer_id;
+}
+
 tr_bool      tr_sessionAllowsDHT( const tr_session * session );
 
 tr_bool      tr_sessionAllowsLPD( const tr_session * session );

libtransmission/test-peer-id.c

@@ -35,25 +35,25 @@ main( void )
 {
     int i;
     int test = 0;
+    uint8_t peer_id[PEER_ID_LEN+1];
 
     for( i = 0; i < 100000; ++i )
     {
-        int       j;
-        int       val = 0;
-        uint8_t * pch = tr_peerIdNew( );
+        int j;
+        int val = 0;
 
-        check( strlen( (char*)pch ) == 20 );
-        check( !memcmp( pch, PEERID_PREFIX, 8 ) );
+        tr_peerIdInit( peer_id );
 
-        for( j = 8; j < 20; ++j )
+        check( strlen( (char*)peer_id ) == PEER_ID_LEN );
+        check( !memcmp( peer_id, PEERID_PREFIX, 8 ) );
+
+        for( j = 8; j < PEER_ID_LEN; ++j )
         {
-            char tmp[2] = { pch[j], '\0' };
+            char tmp[2] = { peer_id[j], '\0' };
             val += strtoul( tmp, NULL, 36 );
         }
 
         check( ( val % 36 ) == 0 );
-
-        tr_free( pch );
     }
 
     return 0;

libtransmission/torrent.c

@@ -1508,7 +1508,6 @@ freeTorrent( tr_torrent * tor )
 
     tr_free( tor->downloadDir );
     tr_free( tor->incompleteDir );
-    tr_free( tor->peer_id );
 
     if( tor == session->torrentList )
         session->torrentList = tor->next;
@@ -1617,8 +1616,7 @@ torrentStart( tr_torrent * tor )
      * closed and opened again without quitting Transmission ...
      * change the peerid. It would help sometimes if a stopped event
      * was missed to ensure that we didn't think someone was cheating. */
-    tr_free( tor->peer_id );
-    tor->peer_id = tr_peerIdNew( );
+    tr_peerIdInit( tor->peer_id );
     tor->isRunning = 1;
     tr_torrentSetDirty( tor );
     tr_runInEventThread( tor->session, torrentStartImpl, tor );

libtransmission/torrent.h

@@ -157,7 +157,7 @@ struct tr_torrent
      * peer_id that was registered by the peer. The peer_id from the tracker
      * and in the handshake are expected to match.
      */
-    uint8_t * peer_id;
+    uint8_t peer_id[PEER_ID_LEN+1];
 
     /* Where the files will be when it's complete */
     char * downloadDir;