No one can get access to buckets now without locking them. Also split up the trackerlogic.c-monster in functional sub-units. HEADS UP: this code is untested and not considered stable.

1 files changed, 107 insertions, 0 deletions

diff --git a/ot_sync.c b/ot_sync.c
new file mode 100644
index 0000000..6e95a98
--- /dev/null
+++ b/ot_sync.c
@@ -0,0 +1,107 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever. */
+
+/* System */
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <stdio.h>
+#include <string.h>
+
+/* Libowfat */
+#include "scan.h"
+#include "byte.h"
+
+/* Opentracker */
+#include "trackerlogic.h"
+#include "ot_mutex.h"
+#include "ot_sync.h"
+
+#ifdef WANT_TRACKER_SYNC
+/* Import Changeset from an external authority
+   format: d4:syncd[..]ee
+   [..]:   ( 20:01234567890abcdefghij16:XXXXYYYY )+
+*/
+int add_changeset_to_tracker( ot_byte *data, size_t len ) {
+  ot_hash    *hash;
+  ot_byte    *end = data + len;
+  unsigned long      peer_count;
+
+  /* We do know, that the string is \n terminated, so it cant
+     overflow */
+  if( byte_diff( data, 8, "d4:syncd" ) ) return -1;
+  data += 8;
+
+  while( 1 ) {
+    if( byte_diff( data, 3, "20:" ) ) {
+      if( byte_diff( data, 2, "ee" ) )
+        return -1;
+      return 0;
+    }
+    data += 3;
+    hash = (ot_hash*)data;
+    data += sizeof( ot_hash );
+
+    /* Scan string length indicator */
+    data += ( len = scan_ulong( (char*)data, &peer_count ) );
+
+    /* If no long was scanned, it is not divisible by 8, it is not
+       followed by a colon or claims to need to much memory, we fail */
+    if( !len || !peer_count || ( peer_count & 7 ) || ( *data++ != ':' ) || ( data + peer_count > end ) )
+      return -1;
+
+    while( peer_count > 0 ) {
+      add_peer_to_torrent( hash, (ot_peer*)data, 1 );
+      data += 8; peer_count -= 8;
+    }
+  }
+  return 0;
+}
+
+/* Proposed output format
+   d4:syncd20:<info_hash>8*N:(xxxxyyyy)*Nee
+*/
+size_t return_changeset_for_tracker( char **reply ) {
+  size_t allocated = 0, i, replysize;
+  ot_vector *torrents_list;
+  int    bucket;
+  char   *r;
+
+  /* Maybe there is time to clean_all_torrents(); */
+
+  /* Determine space needed for whole changeset */
+  for( bucket = 0; bucket < OT_BUCKET_COUNT; ++bucket ) {
+    torrents_list = mutex_bucket_lock(bucket);
+    for( i=0; i<torrents_list->size; ++i ) {
+      ot_torrent *torrent = ((ot_torrent*)(torrents_list->data)) + i;
+      allocated += sizeof( ot_hash ) + sizeof(ot_peer) * torrent->peer_list->changeset.size + 13;
+    }
+    mutex_bucket_unlock(bucket);
+  }
+
+  /* add "d4:syncd" and "ee" */
+  allocated += 8 + 2;
+
+  if( !( r = *reply = mmap( NULL, allocated, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0 ) ) )
+    return 0;
+
+  memmove( r, "d4:syncd", 8 ); r += 8;
+  for( bucket = 0; bucket < OT_BUCKET_COUNT; ++bucket ) {
+    torrents_list = mutex_bucket_lock(bucket);
+    for( i=0; i<torrents_list->size; ++i ) {
+      ot_torrent *torrent = ((ot_torrent*)(torrents_list->data)) + i;
+      const size_t byte_count = sizeof(ot_peer) * torrent->peer_list->changeset.size;
+      *r++ = '2'; *r++ = '0'; *r++ = ':';
+      memmove( r, torrent->hash, sizeof( ot_hash ) ); r += sizeof( ot_hash );
+      r += sprintf( r, "%zd:", byte_count );
+      memmove( r, torrent->peer_list->changeset.data, byte_count ); r += byte_count;
+    }
+    mutex_bucket_unlock(bucket);
+  }
+  *r++ = 'e'; *r++ = 'e';
+
+  replysize = ( r - *reply );
+  fix_mmapallocation( *reply, allocated, replysize );
+
+  return replysize;
+}
+#endif