3 files changed, 572 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..22ddea9
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+CC?=gcc
+CFLAGS+=-I../libowfat -Wall -O2 -pipe
+LDFLAGS+=-L../libowfat/ -lowfat -s
+
+SOURCES=opentracker.c trackerlogic.c
+
+opentracker: $(SOURCES)
+        $(CC) $(SOURCES) -o opentracker $(CFLAGS) $(LDFLAGS)
+
+clean:
+        rm -rf opentracker
diff --git a/opentracker.c b/opentracker.c
new file mode 100644
index 0000000..bd47a24
--- /dev/null
+++ b/opentracker.c
@@ -0,0 +1,288 @@
+#include "socket.h"
+#include "io.h"
+#include "buffer.h"
+#include "ip6.h"
+#include "array.h"
+#include "case.h"
+#include "fmt.h"
+#include "iob.h"
+#include "str.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+static void carp(const char* routine) {
+  buffer_puts(buffer_2,routine);
+  buffer_puts(buffer_2,": ");
+  buffer_puterror(buffer_2);
+  buffer_putnlflush(buffer_2);
+}
+
+static void panic(const char* routine) {
+  carp(routine);
+  exit(111);
+}
+
+struct http_data {
+  array r;
+  io_batch iob;
+  char* hdrbuf;
+  int hlen;
+  int keepalive;
+};
+
+int header_complete(struct http_data* r) {
+  long i;
+  long l=array_bytes(&r->r);
+  const char* c=array_start(&r->r);
+  for (i=0; i+1<l; ++i) {
+    if (c[i]=='\n' && c[i+1]=='\n')
+      return i+2;
+    if (i+3<l &&
+        c[i]=='\r' && c[i+1]=='\n' &&
+        c[i+2]=='\r' && c[i+3]=='\n')
+      return i+4;
+  }
+  return 0;
+}
+
+void httperror(struct http_data* r,const char* title,const char* message) {
+  char* c;
+  c=r->hdrbuf=(char*)malloc(strlen(message)+strlen(title)+200);
+  if (!c) {
+    r->hdrbuf="HTTP/1.0 500 internal error\r\nContent-Type: text/plain\r\nConnection: close\r\n\r\nout of memory\n";
+    r->hlen=strlen(r->hdrbuf);
+  } else {
+    c+=fmt_str(c,"HTTP/1.0 ");
+    c+=fmt_str(c,title);
+    c+=fmt_str(c,"\r\nContent-Type: text/html\r\nConnection: ");
+    c+=fmt_str(c,r->keepalive?"keep-alive":"close");
+    c+=fmt_str(c,"\r\nContent-Length: ");
+    c+=fmt_ulong(c,strlen(message)+strlen(title)+16-4);
+    c+=fmt_str(c,"\r\n\r\n<title>");
+    c+=fmt_str(c,title+4);
+    c+=fmt_str(c,"</title>\n");
+    r->hlen=c - r->hdrbuf;
+  }
+  iob_addbuf(&r->iob,r->hdrbuf,r->hlen);
+}
+
+static struct mimeentry { const char* name, *type; } mimetab[] = {
+  { "html",     "text/html" },
+  { "css",      "text/css" },
+  { "dvi",      "application/x-dvi" },
+  { "ps",       "application/postscript" },
+  { "pdf",      "application/pdf" },
+  { "gif",      "image/gif" },
+  { "png",      "image/png" },
+  { "jpeg",     "image/jpeg" },
+  { "jpg",      "image/jpeg" },
+  { "mpeg",     "video/mpeg" },
+  { "mpg",      "video/mpeg" },
+  { "avi",      "video/x-msvideo" },
+  { "mov",      "video/quicktime" },
+  { "qt",       "video/quicktime" },
+  { "mp3",      "audio/mpeg" },
+  { "ogg",      "audio/x-oggvorbis" },
+  { "wav",      "audio/x-wav" },
+  { "pac",      "application/x-ns-proxy-autoconfig" },
+  { "sig",      "application/pgp-signature" },
+  { "torrent",  "application/x-bittorrent" },
+  { "class",    "application/octet-stream" },
+  { "js",       "application/x-javascript" },
+  { "tar",      "application/x-tar" },
+  { "zip",      "application/zip" },
+  { "dtd",      "text/xml" },
+  { "xml",      "text/xml" },
+  { "xbm",      "image/x-xbitmap" },
+  { "xpm",      "image/x-xpixmap" },
+  { "xwd",      "image/x-xwindowdump" },
+  { 0,0 } };
+
+const char* mimetype(const char* filename) {
+  int i,e=str_rchr(filename,'.');
+  if (filename[e]==0) return "text/plain";
+  ++e;
+  for (i=0; mimetab[i].name; ++i)
+    if (str_equal(mimetab[i].name,filename+e))
+      return mimetab[i].type;
+  return "application/octet-stream";
+}
+
+const char* http_header(struct http_data* r,const char* h) {
+  long i;
+  long l=array_bytes(&r->r);
+  long sl=strlen(h);
+  const char* c=array_start(&r->r);
+  for (i=0; i+sl+2<l; ++i)
+    if (c[i]=='\n' && case_equalb(c+i+1,sl,h) && c[i+sl+1]==':') {
+      c+=i+sl+1;
+      if (*c==' ' || *c=='\t') ++c;
+      return c;
+    }
+  return 0;
+}
+
+void httpresponse(struct http_data* h,int64 s) {
+  char* c;
+  const char* m;
+  array_cat0(&h->r);
+  c=array_start(&h->r);
+  if (byte_diff(c,4,"GET ")) {
+e400:
+    httperror(h,"400 Invalid Request","This server only understands GET.");
+  } else {
+    char *d;
+    int64 fd;
+    struct stat s;
+    c+=4;
+    for (d=c; *d!=' '&&*d!='\t'&&*d!='\n'&&*d!='\r'; ++d) ;
+    if (*d!=' ') goto e400;
+    *d=0;
+    if (c[0]!='/') goto e404;
+    while (c[1]=='/') ++c;
+    if (!io_readfile(&fd,c+1)) {
+e404:
+      httperror(h,"404 Not Found","No such file or directory.");
+    } else {
+      if (fstat(fd,&s)==-1) {
+        io_close(fd);
+        goto e404;
+      }
+      if ((m=http_header(h,"Connection"))) {
+        if (str_equal(m,"keep-alive"))
+          h->keepalive=1;
+        else
+          h->keepalive=0;
+      } else {
+        if (byte_equal(d+1,8,"HTTP/1.0"))
+          h->keepalive=0;
+        else
+          h->keepalive=1;
+      }
+      m=mimetype(c);
+      c=h->hdrbuf=(char*)malloc(500);
+      c+=fmt_str(c,"HTTP/1.1 Coming Up\r\nContent-Type: ");
+      c+=fmt_str(c,m);
+      c+=fmt_str(c,"\r\nContent-Length: ");
+      c+=fmt_ulonglong(c,s.st_size);
+      c+=fmt_str(c,"\r\nLast-Modified: ");
+      c+=fmt_httpdate(c,s.st_mtime);
+      c+=fmt_str(c,"\r\nConnection: ");
+      c+=fmt_str(c,h->keepalive?"keep-alive":"close");
+      c+=fmt_str(c,"\r\n\r\n");
+      iob_addbuf(&h->iob,h->hdrbuf,c - h->hdrbuf);
+      iob_addfile(&h->iob,fd,0,s.st_size);
+    }
+  }
+  io_dontwantread(s);
+  io_wantwrite(s);
+}
+
+int main() {
+  int s=socket_tcp6b();
+  uint32 scope_id;
+  char ip[16];
+  uint16 port;
+  if (socket_bind6_reuse(s,V6any,8000,0)==-1)
+    panic("socket_bind6_reuse");
+  if (socket_listen(s,16)==-1)
+    panic("socket_listen");
+  if (!io_fd(s))
+    panic("io_fd");
+  io_wantread(s);
+  for (;;) {
+    int64 i;
+    io_wait();
+    while ((i=io_canread())!=-1) {
+      if (i==s) {
+        int n;
+        while ((n=socket_accept6(s,ip,&port,&scope_id))!=-1) {
+          char buf[IP6_FMT];
+          buffer_puts(buffer_2,"accepted new connection from ");
+          buffer_put(buffer_2,buf,fmt_ip6(buf,ip));
+          buffer_puts(buffer_2,":");
+          buffer_putulong(buffer_2,port);
+          buffer_puts(buffer_2," (fd ");
+          buffer_putulong(buffer_2,n);
+          buffer_puts(buffer_2,")");
+          if (io_fd(n)) {
+            struct http_data* h=(struct http_data*)malloc(sizeof(struct http_data));
+            io_wantread(n);
+            if (h) {
+              byte_zero(h,sizeof(struct http_data));
+              io_setcookie(n,h);
+            } else
+              io_close(n);
+          } else {
+            buffer_puts(buffer_2,", but io_fd failed.");
+            io_close(n);
+          }
+          buffer_putnlflush(buffer_2);
+        }
+        if (errno==EAGAIN)
+          io_eagain(s);
+        else
+          carp("socket_accept6");
+      } else {
+        char buf[8192];
+        struct http_data* h=io_getcookie(i);
+        int l=io_tryread(i,buf,sizeof buf);
+        if (l==-3) {
+          if (h) {
+            array_reset(&h->r);
+            iob_reset(&h->iob);
+            free(h->hdrbuf); h->hdrbuf=0;
+          }
+          buffer_puts(buffer_2,"io_tryread(");
+          buffer_putulong(buffer_2,i);
+          buffer_puts(buffer_2,"): ");
+          buffer_puterror(buffer_2);
+          buffer_putnlflush(buffer_2);
+          io_close(i);
+        } else if (l==0) {
+          if (h) {
+            array_reset(&h->r);
+            iob_reset(&h->iob);
+            free(h->hdrbuf); h->hdrbuf=0;
+          }
+          buffer_puts(buffer_2,"eof on fd #");
+          buffer_putulong(buffer_2,i);
+          buffer_putnlflush(buffer_2);
+          io_close(i);
+        } else if (l>0) {
+          array_catb(&h->r,buf,l);
+          if (array_failed(&h->r)) {
+            httperror(h,"500 Server Error","request too long.");
+emerge:
+            io_dontwantread(i);
+            io_wantwrite(i);
+          } else if (array_bytes(&h->r)>8192) {
+            httperror(h,"500 request too long","You sent too much headers");
+            goto emerge;
+          } else if ((l=header_complete(h)))
+            httpresponse(h,i);
+        }
+      }
+    }
+    while ((i=io_canwrite())!=-1) {
+      struct http_data* h=io_getcookie(i);
+      int64 r=iob_send(i,&h->iob);
+/*      printf("iob_send returned %lld\n",r); */
+      if (r==-1) io_eagain(i); else
+      if (r<=0) {
+        array_trunc(&h->r);
+        iob_reset(&h->iob);
+        free(h->hdrbuf); h->hdrbuf=0;
+        if (h->keepalive) {
+          io_dontwantwrite(i);
+          io_wantread(i);
+        } else
+          io_close(i);
+      }
+    }
+  }
+  return 0;
+}
diff --git a/trackerlogic.c b/trackerlogic.c
new file mode 100644
index 0000000..d21fc01
--- /dev/null
+++ b/trackerlogic.c
@@ -0,0 +1,273 @@
+// THIS REALLY BELONGS INTO A HEADER FILE
+//
+//
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+typedef unsigned char ot_hash[20];
+typedef unsigned char ot_ip[ 4/*0*/ ];
+typedef unsigned long ot_time;
+// tunables
+const unsigned long OT_TIMEOUT          = 2700;
+const unsigned long OT_HUGE_FILESIZE    = 1024*1024*256; // Thats 256MB per file, enough for 204800 peers of 128 bytes
+
+#define OT_COMPACT_ONLY
+
+#define MEMMOVE              memmove
+#define BZERO                bzero
+#define FORMAT_FIXED_STRING  sprintf
+#define FORMAT_FORMAT_STRING sprintf
+#define BINARY_FIND          binary_search
+
+typedef struct {
+#ifndef OT_COMPACT_ONLY
+  ot_hash         id;
+  ot_hash         key;
+#endif
+  ot_ip           ip;
+  unsigned short  port;
+  ot_time         death;
+  unsigned char   flags;
+} ot_peer;
+unsigned char PEER_FLAG_SEEDING   = 0x80;
+unsigned char PEER_IP_LENGTH_MASK = 0x3f;
+
+typedef struct {
+  ot_hash         hash;
+  ot_peer        *peer_list;
+  unsigned long   peer_count;
+  unsigned long   seed_count;
+} ot_torrent;
+
+void *map_file( char *file_name );
+
+// This behaves quite like bsearch but allows to find
+// the insertion point for inserts after unsuccessful searches
+// in this case exactmatch is 0 on exit
+//
+void *binary_search( const void *key, const void *base,
+                     const unsigned long member_count, const unsigned long member_size,
+                     int (*compar) (const void *, const void *),
+                     int *exactmatch );
+
+int compare_hash( const void *hash1, const void *hash2 ) { return memcmp( hash1, hash2, sizeof( ot_hash )); }
+int compare_ip_port( const void *peer1, const void *peer2 ) { return memcmp( peer1, peer2, 6); }
+
+//
+//
+// END OF STUFF THAT BELONGS INTO A HEADER FILE
+
+ot_torrent *torrents_pointer = 0;
+unsigned long torrents_count = 0;
+unsigned char *scratchspace;
+
+ot_torrent *add_peer_to_torrent( ot_hash hash, ot_peer *peer ) {
+  ot_torrent *torrent;
+  ot_peer    *peer_dest;
+  int exactmatch;
+
+  torrent = BINARY_FIND( hash, torrents_pointer, torrents_count, sizeof( ot_torrent ), compare_hash, &exactmatch );
+  if( !exactmatch ) {
+    // Assume, OS will provide us with space, after all, this is file backed
+    MEMMOVE( torrent + 1, torrent, ( torrents_pointer + torrents_count ) - torrent );
+
+    // Create a new torrent entry, then
+    MEMMOVE( &torrent->hash, hash, sizeof( ot_hash ) );
+    torrent->peer_list  = map_file( hash );
+    torrent->peer_count = 0;
+    torrent->seed_count = 0;
+  }
+
+  peer_dest = BINARY_FIND( peer, torrent->peer_list, torrent->peer_count, sizeof( ot_peer ), compare_ip_port, &exactmatch );
+  if( exactmatch ) {
+    // If peer was a seeder but isn't anymore, decrease seeder count
+    if( ( peer_dest->flags & PEER_FLAG_SEEDING ) && !( peer->flags & PEER_FLAG_SEEDING ) )
+      torrent->seed_count--;
+    if( !( peer_dest->flags & PEER_FLAG_SEEDING ) && ( peer->flags & PEER_FLAG_SEEDING ) )
+      torrent->seed_count++;
+  } else {
+    // Assume, OS will provide us with space, after all, this is file backed
+    MEMMOVE( peer_dest + 1, peer_dest, ( torrent->peer_list + torrent->peer_count ) - peer_dest );
+
+    // Create a new peer entry, then
+    MEMMOVE( peer_dest, peer, sizeof( ot_peer ) );
+
+    torrent->peer_count++;
+    torrent->seed_count+= ( peer->flags & PEER_FLAG_SEEDING ) ? 1 : 0;
+  }
+
+  // Set new time out time
+  peer_dest->death = now() + OT_TIMEOUT;
+
+  return torrent;
+}
+
+#define SETINVALID( i )   (scratchspace[index] = 3);
+#define SETSELECTED( i )  (scratchspace[index] = 1);
+#define TESTSELECTED( i ) (scratchspace[index] == 1 )
+#define TESTSET( i )      (scratchspace[index])
+#define RANDOM            random()
+
+inline int TESTVALIDPEER( ot_peer *p ) { return p->death > now(); }
+
+// Compiles a list of random peers for a torrent
+// * scratch space keeps track of death or already selected peers
+// * reply must have enough space to hold 1+(1+16+2+1)*amount+1 bytes
+// * Selector function can be anything, maybe test for seeds, etc.
+// * that RANDOM may return huge values
+// * does not yet check not to return self
+// * it is not guaranteed to see all peers, so no assumptions on active seeders/peers may be done
+// * since compact format cannot handle v6 addresses, it must be enabled by OT_COMPACT_ONLY
+//
+void return_peers_for_torrent( ot_torrent *torrent, unsigned long amount, char *reply ) {
+  register ot_peer *peer_base = torrent->peer_list;
+  unsigned long     peer_count = torrent->peer_count;
+  unsigned long     selected_count = 0, invalid_count = 0;
+  unsigned long     index = 0;
+
+  // optimize later ;)
+  BZERO( scratchspace, peer_count );
+
+  while( ( selected_count < amount ) && ( selected_count + invalid_count < peer_count ) ) {
+    // skip to first non-flagged peer
+    while( TESTSET(index) ) index = ( index + 1 ) % peer_count;
+
+    if( TESTVALIDPEER( peer_base + index ) ) {
+      SETINVALID(index); invalid_count++;
+    } else {
+      SETSELECTED(index); selected_count++;
+      index = ( index + RANDOM ) % peer_count;
+    }
+  }
+
+  // Now our scratchspace contains a list of selected_count valid peers
+  // Collect them into a reply string
+  index = 0;
+
+#ifndef OT_COMPACT_ONLY
+  reply += FORMAT_FIXED_STRING( reply, "d5:peersl" );
+#else
+  reply += FORMAT_FORMAT_STRING( reply, "d5:peers%i:",6*selected_count );
+#endif
+
+  while( selected_count-- ) {
+    ot_peer *peer;
+    while( !TESTSELECTED( index ) ) ++index;
+    peer = peer_base + index;
+#ifdef OT_COMPACT_ONLY
+    MEMMOVE( reply, &peer->ip, 4 );
+    MEMMOVE( reply+4, &peer->port, 2 );
+    reply += 6;
+#else
+    reply += FORMAT_FORMAT_STRING( reply, "d2:ip%d:%s7:peer id20:%20c4:porti%ie",
+      peer->flags & PEER_IP_LENGTH_MASK,
+      peer->ip,
+      peer->id,
+      peer->port );
+#endif
+  }
+#ifndef OT_COMPACT_ONLY
+  reply += FORMAT_FIXED_STRING( reply, "ee" );
+#else
+  reply += FORMAT_FIXED_STRING( reply, "e" );
+#endif
+}
+
+// Compacts a torrents peer list
+// * torrents older than OT_TIMEOUT are being kicked
+// * is rather expansive
+// * if this fails, torrent file is invalid, should add flag
+//
+void heal_torrent( ot_torrent *torrent ) {
+  unsigned long index = 0, base = 0, end, seed_count = 0;
+
+  // Initialize base to first dead peer.
+  while( ( base < torrent->peer_count ) && torrent->peer_list[base].death <= now() ) {
+    seed_count += ( torrent->peer_list[base].flags & PEER_FLAG_SEEDING ) ? 1 : 0;
+    base++;
+  }
+
+  // No dead peers? Home.
+  if( base == torrent->peer_count ) return;
+
+  // From now index always looks to the next living peer while base keeps track of
+  // the dead peer that marks the beginning of insert space.
+  index = base + 1;
+
+  while( 1 ) {
+    // Let index search for next living peer
+    while( ( index < torrent->peer_count ) && torrent->peer_list[index].death > now() ) index++;
+
+    // No further living peers found - base is our new peer count
+    if( index == torrent->peer_count ) {
+      torrent->peer_count = base;
+      torrent->seed_count = seed_count;
+      return;
+    }
+
+    end = index + 1;
+
+    // Let end search for next dead peer (end of living peers)
+    while( ( end < torrent->peer_count ) && torrent->peer_list[end].death <= now() ) {
+      seed_count += ( torrent->peer_list[end].flags & PEER_FLAG_SEEDING ) ? 1 : 0;
+      end++;
+    }
+
+    // We either hit a dead peer or the end of our peers
+    // In both cases: move block towards base
+    MEMMOVE( torrent->peer_list + base, torrent->peer_list + index, ( end - index ) * sizeof( ot_peer ) );
+    base += end - index;
+
+    index = end;
+  }
+}
+
+void *binary_search( const void *key, const void *base,
+                     unsigned long member_count, const unsigned long member_size,
+                     int (*compar) (const void *, const void *),
+                     int *exactmatch ) {
+  unsigned char *lookat = ((unsigned char*)base) + member_size * (member_count >> 1);
+  *exactmatch = 1;
+
+  while( member_count ) {
+    int cmp = compar((void*)lookat, key);
+    if (cmp == 0) return (void *)lookat;
+    if (cmp < 0) {
+      base = (void*)(lookat + member_size);
+      --member_count;
+    }
+    member_count >>= 1;
+    lookat = ((unsigned char*)base) + member_size * (member_count >> 1);
+  }
+  *exactmatch = 0;
+  return (void*)lookat;
+
+}
+
+// This function maps a "huge" file into process space
+// * I guess, we should be checking for more errors...
+void *map_file( char *file_name ) {
+  char *map;
+  int file_desc=open(file_name,O_RDWR|O_CREAT|O_NDELAY,0644);
+
+  if( file_desc < 0) return 0;
+
+  map=mmap(0,OT_HUGE_FILESIZE,PROT_READ|PROT_WRITE,MAP_SHARED,file_desc,0);
+  close(file_desc);
+
+  return (map == (char*)-1) ? 0 : map;
+}
+
+int init_logic( ) {
+  unlink( "./opentracker_map_index.idx" );
+  torrents_pointer = map_file( "./opentracker_map_index.idx" );
+  torrents_count   = 0;
+  scratchspace     = map_file( "./scratchspace" );
+}
+
+void deinit_logic( ) {
+  unmap_file( torrents_pointer );
+}