2 files changed, 271 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index a18fb3e..269a109 100644
--- a/Makefile
+++ b/Makefile
@@ -60,6 +60,8 @@ $(BINARY): $(OBJECTS) $(HEADERS)
         strip $@
 $(BINARY).debug: $(OBJECTS_debug) $(HEADERS)
         $(CC) -o $@ $(OBJECTS_debug) $(LDFLAGS)
+proxy: proxy.o ot_vector.o $(HEADERS)
+        $(CC) -o $@ proxy.o ot_vector.o $(LDFLAGS)
 
 .c.debug.o : $(HEADERS)
         $(CC) -c -o $@ $(CFLAGS_debug) $(<:.debug.o=.c)
diff --git a/proxy.c b/proxy.c
new file mode 100644
index 0000000..ca5a773
--- /dev/null
+++ b/proxy.c
@@ -0,0 +1,269 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever.
+
+   $Id$ */
+
+/* System */
+#include <stdlib.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <pwd.h>
+#include <ctype.h>
+
+/* Libowfat */
+#include "socket.h"
+#include "io.h"
+#include "iob.h"
+#include "byte.h"
+#include "scan.h"
+#include "ip6.h"
+#include "ndelay.h"
+
+/* Opentracker */
+#include "trackerlogic.h"
+#include "ot_livesync.h"
+
+uint32_t g_tracker_id;
+char groupip_1[4] = { 224,0,23,5 };
+
+#define LIVESYNC_INCOMING_BUFFSIZE          (256*256)
+
+#define LIVESYNC_OUTGOING_BUFFSIZE_PEERS     1480
+#define LIVESYNC_OUTGOING_WATERMARK_PEERS   (sizeof(ot_peer)+sizeof(ot_hash))
+
+enum { OT_SYNC_PEER };
+
+/* For outgoing packets */
+static int64    g_socket_in = -1;
+
+/* For incoming packets */
+static int64    g_socket_out = -1;
+static uint8_t  g_inbuffer[LIVESYNC_INCOMING_BUFFSIZE];
+
+void exerr( char * message ) {
+  fprintf( stderr, "%s\n", message );
+  exit( 111 );
+}
+
+void livesync_bind_mcast( ot_ip6 ip, uint16_t port) {
+  char tmpip[4] = {0,0,0,0};
+  char *v4ip;
+
+  if( !ip6_isv4mapped(ip))
+    exerr("v6 mcast support not yet available.");
+  v4ip = ip+12;
+
+  if( g_socket_in != -1 )
+    exerr("Error: Livesync listen ip specified twice.");
+
+  if( ( g_socket_in = socket_udp4( )) < 0)
+    exerr("Error: Cant create live sync incoming socket." );
+  ndelay_off(g_socket_in);
+
+  if( socket_bind4_reuse( g_socket_in, tmpip, port ) == -1 )
+    exerr("Error: Cant bind live sync incoming socket." );
+
+  if( socket_mcjoin4( g_socket_in, groupip_1, v4ip ) )
+    exerr("Error: Cant make live sync incoming socket join mcast group.");
+
+  if( ( g_socket_out = socket_udp4()) < 0)
+    exerr("Error: Cant create live sync outgoing socket." );
+  if( socket_bind4_reuse( g_socket_out, v4ip, port ) == -1 )
+    exerr("Error: Cant bind live sync outgoing socket." );
+
+  socket_mcttl4(g_socket_out, 1);
+  socket_mcloop4(g_socket_out, 1);
+}
+
+static ot_vector all_torrents[OT_BUCKET_COUNT];
+ot_vector *mutex_bucket_lock_by_hash( ot_hash hash ) {
+  return all_torrents + ( uint32_read_big( (char*)hash ) >> OT_BUCKET_COUNT_SHIFT );
+}
+ot_vector *mutex_bucket_lock( int bucket ) {
+  return all_torrents + bucket;
+}
+#define mutex_bucket_unlock_by_hash(A,B)
+#define mutex_bucket_unlock(A)
+
+size_t add_peer_to_torrent_proxy( ot_hash hash, ot_peer *peer ) {
+  int         exactmatch;
+  ot_torrent *torrent;
+  ot_peer    *peer_dest;
+  ot_vector  *torrents_list = mutex_bucket_lock_by_hash( hash );
+
+  torrent = vector_find_or_insert( torrents_list, (void*)hash, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch );
+  if( !torrent )
+    return -1;
+
+  if( !exactmatch ) {
+    /* Create a new torrent entry, then */
+    memcpy( torrent->hash, hash, sizeof(ot_hash) );
+
+    if( !( torrent->peer_list = malloc( sizeof (ot_peerlist) ) ) ) {
+      vector_remove_torrent( torrents_list, torrent );
+      return -1;
+    }
+
+    byte_zero( torrent->peer_list, sizeof( ot_peerlist ) );
+  }
+
+  /* Check for peer in torrent */
+  peer_dest = vector_find_or_insert_peer( &(torrent->peer_list->peers), peer, &exactmatch );
+  if( !peer_dest ) return -1;
+
+  /* Tell peer that it's fresh */
+  OT_PEERTIME( peer ) = 0;
+
+  /* If we hadn't had a match create peer there */
+  if( !exactmatch ) {
+    torrent->peer_list->peer_count++;
+    if( OT_PEERFLAG(peer) & PEER_FLAG_SEEDING )
+      torrent->peer_list->seed_count++;
+  }
+  memcpy( peer_dest, peer, sizeof(ot_peer) );
+  return 0;
+}
+
+size_t remove_peer_from_torrent_proxy( ot_hash hash, ot_peer *peer ) {
+  int          exactmatch;
+  ot_vector   *torrents_list = mutex_bucket_lock_by_hash( hash );
+  ot_torrent  *torrent = binary_search( hash, torrents_list->data, torrents_list->size, sizeof( ot_torrent ), OT_HASH_COMPARE_SIZE, &exactmatch );
+
+  if( exactmatch ) {
+    ot_peerlist *peer_list = torrent->peer_list;
+    switch( vector_remove_peer( &peer_list->peers, peer ) ) {
+      case 2:  peer_list->seed_count--; /* Fall throughs intended */
+      case 1:  peer_list->peer_count--; /* Fall throughs intended */
+      default: break;
+    }
+  }
+
+  return 0;
+}
+
+void free_peerlist( ot_peerlist *peer_list ) {
+  if( peer_list->peers.data ) {
+    if( OT_PEERLIST_HASBUCKETS( peer_list ) ) {
+      ot_vector *bucket_list = (ot_vector*)(peer_list->peers.data);
+
+      while( peer_list->peers.size-- )
+        free( bucket_list++->data );
+    }
+    free( peer_list->peers.data );
+  }
+  free( peer_list );
+}
+
+static void livesync_handle_peersync( ssize_t datalen ) {
+  int off = sizeof( g_tracker_id ) + sizeof( uint32_t );
+
+  /* Now basic sanity checks have been done on the live sync packet
+     We might add more testing and logging. */
+  while( off + (ssize_t)sizeof( ot_hash ) + (ssize_t)sizeof( ot_peer ) <= datalen ) {
+    ot_peer *peer = (ot_peer*)(g_inbuffer + off + sizeof(ot_hash));
+    ot_hash *hash = (ot_hash*)(g_inbuffer + off);
+
+    if( OT_PEERFLAG(peer) & PEER_FLAG_STOPPED )
+      remove_peer_from_torrent_proxy( *hash, peer );
+    else
+      add_peer_to_torrent_proxy( *hash, peer );
+
+    off += sizeof( ot_hash ) + sizeof( ot_peer );
+  }
+}
+
+int usage( char *self ) {
+  fprintf( stderr, "Usage: %s -i ip -p port\n", self );
+  return 0;
+}
+
+static ot_vector all_torrents[1024];
+static uint32_t peer_counts[1024];
+#ifdef WANT_SCROOOOOOOLL
+static char*to_hex(char*d,uint8_t*s){char*m="0123456789ABCDEF";char *t=d;char*e=d+40;while(d<e){*d++=m[*s>>4];*d++=m[*s++&15];}*d=0;return t;}
+#endif
+
+int main( int argc, char **argv ) {
+  ot_ip6 serverip;
+  uint16_t tmpport;
+  int scanon = 1, bound = 0;
+  time_t next_dump = time(NULL)+1;
+
+  srandom( time(NULL) );
+  g_tracker_id = random();
+
+  while( scanon ) {
+    switch( getopt( argc, argv, ":i:p:vh" ) ) {
+    case -1: scanon = 0; break;
+    case 'i': 
+      if( !scan_ip6( optarg, serverip )) { usage( argv[0] ); exit( 1 ); }
+      break;
+    case 'p':
+      if( !scan_ushort( optarg, &tmpport)) { usage( argv[0] ); exit( 1 ); }
+      livesync_bind_mcast( serverip, tmpport); bound++; break;
+    default:
+    case '?': usage( argv[0] ); exit( 1 );
+    }
+  }
+
+  if( !bound ) exerr( "No port bound." );
+
+  while( 1 ) {
+    ot_ip6 in_ip; uint16_t in_port;
+    size_t datalen = socket_recv4(g_socket_in, (char*)g_inbuffer, LIVESYNC_INCOMING_BUFFSIZE, 12+(char*)in_ip, &in_port);
+
+    /* Expect at least tracker id and packet type */
+    if( datalen <= (ssize_t)(sizeof( g_tracker_id ) + sizeof( uint32_t )) )
+      continue;
+    if( !memcmp( g_inbuffer, &g_tracker_id, sizeof( g_tracker_id ) ) ) {
+      /* drop packet coming from ourselves */
+      continue;
+    }
+
+    switch( uint32_read_big( sizeof( g_tracker_id ) + (char*)g_inbuffer ) ) {
+    case OT_SYNC_PEER:
+      livesync_handle_peersync( datalen );
+      break;
+    default:
+      fprintf( stderr, "Received an unknown live sync packet type %u.\n", uint32_read_big( sizeof( g_tracker_id ) + (char*)g_inbuffer ) );
+      break;
+    }
+    if( time(NULL) > next_dump ) {
+      int bucket, i;
+      /* For each bucket... */
+      for( bucket=0; bucket<OT_BUCKET_COUNT; ++bucket ) {
+        /* Get exclusive access to that bucket */
+        ot_vector *torrents_list = mutex_bucket_lock( bucket );
+        size_t tor_offset;
+
+        /* For each torrent in this bucket.. */
+        for( tor_offset=0; tor_offset<torrents_list->size; ++tor_offset ) {
+          /* Address torrents members */
+          ot_peerlist *peer_list = ( ((ot_torrent*)(torrents_list->data))[tor_offset] ).peer_list;
+#ifdef WANT_SCROOOOOOOLL
+          ot_hash     *hash      =&( ((ot_torrent*)(torrents_list->data))[tor_offset] ).hash;
+          char hash_out[41];
+          to_hex(hash_out,*hash);
+          printf( "%s %08zd\n", hash_out, peer_list->peer_count );
+#endif
+          if(peer_list->peer_count<1024) peer_counts[peer_list->peer_count]++; else peer_counts[1023]++;
+          free_peerlist(peer_list);
+        }
+        free( torrents_list->data );
+        memset( torrents_list, 0, sizeof(*torrents_list ) );
+      }
+      for( i=1023; i>=0; --i )
+        if( peer_counts[i] ) {
+          printf( "%d:%d ", i, peer_counts[i] );
+          peer_counts[i] = 0;
+        }
+      printf( "\n" );
+      next_dump = time(NULL) + 1;
+    } 
+  }
+}