Changeset 3104

Timestamp:

Sep 20, 2007, 3:59:48 PM (16 years ago)

Author:

charles

Message:

• don't initiate a new connection to a peer that we're already handshaking with
• don't accidentally connect to ourselves. :)

Location:

branches/encryption/libtransmission

Files:

• handshake.c (modified) (8 diffs)
• handshake.h (modified) (2 diffs)
• peer-mgr.c (modified) (5 diffs)
• utils.c (modified) (1 diff)
• utils.h (modified) (1 diff)

branches/encryption/libtransmission/handshake.c

@@ -39 +39 @@
 ***/
 
-#define HANDSHAKE_NAME          "\023BitTorrent protocol"
-#define HANDSHAKE_NAME_LEN      20
-#define HANDSHAKE_FLAGS_LEN     8
-#define HANDSHAKE_SIZE          68
-
-/***
-****
-***/
+#define HANDSHAKE_NAME "\023BitTorrent protocol"
 
 enum
 {
+    /* BitTorrent Handshake Constants */
+    HANDSHAKE_NAME_LEN             = 20,
+    HANDSHAKE_FLAGS_LEN            = 8,
+    HANDSHAKE_SIZE                 = 68,
+    PEER_ID_LEN                    = 20,
+
+    /* Extension Negotiation Constants */
     HANDSHAKE_EXTPREF_LTEP_FORCE   = 0x0,
     HANDSHAKE_EXTPREF_LTEP_PREFER  = 0x1,
     HANDSHAKE_EXTPREF_AZMP_PREFER  = 0x2,
-    HANDSHAKE_EXTPREF_AZMP_FORCE   = 0x3
+    HANDSHAKE_EXTPREF_AZMP_FORCE   = 0x3,
+
+    /* Encryption Constants */
+    PadA_MAXLEN                    = 512,
+    PadB_MAXLEN                    = 512,
+    PadC_MAXLEN                    = 512,
+    PadD_MAXLEN                    = 512,
+    VC_LENGTH                      = 8,
+    KEY_LEN                        = 96
 };
 
@@ -78 +86 @@
 #define HANDSHAKE_GET_EXTPREF( reserved )      ( (reserved)[5] & 0x03 )
 #define HANDSHAKE_SET_EXTPREF( reserved, val ) ( (reserved)[5] |= 0x03 & (val) )
-#define HANDSHAKE_EXTPREF_LTEP_FORCE   ( 0x0 )
-#define HANDSHAKE_EXTPREF_LTEP_PREFER  ( 0x1 )
-#define HANDSHAKE_EXTPREF_AZMP_PREFER  ( 0x2 )
-#define HANDSHAKE_EXTPREF_AZMP_FORCE   ( 0x3 )
-
-enum
-{
-    PadA_MAXLEN = 512,
-    PadB_MAXLEN = 512,
-    PadC_MAXLEN = 512,
-    PadD_MAXLEN = 512
-};
 
 extern const char* getPeerId( void ) ;
-
-#define KEY_LEN 96
-#define VC_LENGTH 8
 
 struct tr_handshake
@@ -105 +98 @@
     tr_crypto * crypto;
     struct tr_handle * handle;
-    uint8_t myPublicKey[96];
-    uint8_t mySecret[96];
+    uint8_t myPublicKey[KEY_LEN];
+    uint8_t mySecret[KEY_LEN];
     uint8_t state;
     uint16_t pad_c_len;
@@ -113 +106 @@
     uint32_t crypto_select;
     uint8_t myReq1[SHA_DIGEST_LENGTH];
-    uint8_t peer_id[20];
+    uint8_t peer_id[PEER_ID_LEN];
     handshakeDoneCB doneCB;
     void * doneUserData;
@@ -496 +489 @@
     uint8_t pstrlen;
     uint8_t * pstr;
-    uint8_t reserved[8];
+    uint8_t reserved[HANDSHAKE_FLAGS_LEN];
     uint8_t hash[SHA_DIGEST_LENGTH];
 
@@ -503 +496 @@
     if( EVBUFFER_LENGTH(inbuf) < HANDSHAKE_SIZE )
         return READ_MORE;
-
-for( i=0; i<(int)EVBUFFER_LENGTH(inbuf); ++i )
-fprintf( stderr, "[%c]", EVBUFFER_DATA(inbuf)[i] );
-fprintf( stderr, "\n" );
 
     pstrlen = EVBUFFER_DATA(inbuf)[0]; /* peek, don't read.  We may be
@@ -583 +572 @@
     tr_peerIoSetPeersId( handshake->io, handshake->peer_id );
     handshake->havePeerID = TRUE;
+    dbgmsg( handshake, "peer-id is [%*.*s]", PEER_ID_LEN, PEER_ID_LEN, handshake->peer_id );
+    if( !memcmp( handshake->peer_id, getPeerId(), PEER_ID_LEN ) ) {
+        dbgmsg( handshake, "streuth!  we've connected to ourselves." );
+        tr_handshakeDone( handshake, FALSE );
+        return READ_DONE;
+    }
 
     /**
@@ -890 +885 @@
     return handshake;
 }
+
+const struct in_addr *
+tr_handshakeGetAddr( const struct tr_handshake * handshake, uint16_t * port )
+{
+    assert( handshake != NULL );
+    assert( handshake->io != NULL );
+
+    return tr_peerIoGetAddress( handshake->io, port );
+}
+
+

branches/encryption/libtransmission/handshake.h

@@ -16 +16 @@
 #include "transmission.h"
 
+struct in_addr;
 struct tr_peerIo;
 typedef struct tr_handshake tr_handshake;
@@ -31 +32 @@
                                  void               * doneUserData );
 
+const struct in_addr * tr_handshakeGetAddr( const struct tr_handshake * handshake,
+                                            uint16_t                  * setme_port );
+
 void tr_handshakeAbort( tr_handshake  * handshake );
 

branches/encryption/libtransmission/peer-mgr.c

@@ -71 +71 @@
 
 static int
+handshakeCompareToAddr( const void * va, const void * vb )
+{
+    const tr_handshake * a = va;
+    const struct in_addr * b = vb;
+    return memcmp( tr_handshakeGetAddr( a, NULL ), b, sizeof( struct in_addr ) );
+}
+
+static int
+handshakeCompare( const void * va, const void * vb )
+{
+    const tr_handshake * a = va;
+    const tr_handshake * b = vb;
+    return memcmp( tr_handshakeGetAddr( a, NULL ),
+                   tr_handshakeGetAddr( b, NULL ),
+                   sizeof( struct in_addr ) );
+}
+
+static tr_handshake*
+getExistingHandshake( tr_peerMgr * mgr, const struct in_addr * in_addr )
+{
+    return tr_ptrArrayFindSorted( mgr->handshakes,
+                                  in_addr,
+                                  handshakeCompareToAddr );
+}
+
+/**
+***
+**/
+
+static int
 torrentCompare( const void * va, const void * vb )
 {
-    const Torrent * a = (const Torrent*) va;
-    const Torrent * b = (const Torrent*) vb;
+    const Torrent * a = va;
+    const Torrent * b = vb;
     return memcmp( a->hash, b->hash, SHA_DIGEST_LENGTH );
 }
@@ -546 +576 @@
     ours = tr_ptrArrayRemoveSorted( manager->handshakes,
                                     handshake,
-                                    tr_comparePointers );
+                                    handshakeCompare );
     assert( handshake == ours );
 
@@ -609 +639 @@
     ++manager->connectionCount;
 
-    tr_ptrArrayInsertSorted( manager->handshakes, handshake, tr_comparePointers );
+    tr_ptrArrayInsertSorted( manager->handshakes, handshake, handshakeCompare );
 }
 
@@ -617 +647 @@
                        int               socket )
 {
-    tr_peerIo * io = tr_peerIoNewIncoming( manager->handle, addr, socket );
-    initiateHandshake( manager, io );
+    if( getExistingHandshake( manager, addr ) == NULL )
+    {
+        tr_peerIo * io = tr_peerIoNewIncoming( manager->handle, addr, socket );
+        initiateHandshake( manager, io );
+    }
 }
 
@@ -636 +669 @@
     if( !t->isRunning ) { /* torrent's not running */
         fprintf( stderr, "OUTGOING connection not being made because t [%s] is not running\n", t->tor->info.name );
+        return;
+    }
+    if( getExistingHandshake( manager, &peer->in_addr ) != NULL ) { /* already have a handshake pending */
+        fprintf( stderr, "already have a handshake for that address\n" );
         return;
     }

branches/encryption/libtransmission/utils.c

@@ -333 +333 @@
 }
 
-int
-tr_comparePointers( const void * a, const void * b )
-{
-    return a - b;
-}
-
 /**
 ***

branches/encryption/libtransmission/utils.h

@@ -155 +155 @@
 int tr_compareUint64( uint64_t a, uint64_t b );
 
-int tr_comparePointers( const void * a, const void * b );
-
 /***
 ****