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opentracker – An open and free bittorrent tracker
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opentracker/proxy.c

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/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
$Id$ */
/* System */
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <pthread.h>
#include <pwd.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
/* Libowfat */
#include "byte.h"
#include "io.h"
#include "iob.h"
#include "ip6.h"
#include "ndelay.h"
#include "scan.h"
#include "socket.h"
/* Opentracker */
#include "ot_mutex.h"
#include "ot_stats.h"
#include "ot_vector.h"
#include "trackerlogic.h"
#ifndef WANT_SYNC_LIVE
#define WANT_SYNC_LIVE
#endif
#include "ot_livesync.h"
ot_ip6 g_serverip;
uint16_t g_serverport = 9009;
uint32_t g_tracker_id;
char groupip_1[4] = {224, 0, 23, 5};
int g_self_pipe[2];
/* If you have more than 10 peers, don't use this proxy
Use 20 slots for 10 peers to have room for 10 incoming connection slots
*/
#define MAX_PEERS 20
#define LIVESYNC_INCOMING_BUFFSIZE (256 * 256)
#define STREAMSYNC_OUTGOING_BUFFSIZE (256 * 256)
#define LIVESYNC_OUTGOING_BUFFSIZE_PEERS 1480
#define LIVESYNC_OUTGOING_WATERMARK_PEERS (sizeof(ot_peer) + sizeof(ot_hash))
#define LIVESYNC_MAXDELAY 15 /* seconds */
/* The amount of time a complete sync cycle should take */
#define OT_SYNC_INTERVAL_MINUTES 2
/* So after each bucket wait 1 / OT_BUCKET_COUNT intervals */
#define OT_SYNC_SLEEP (((OT_SYNC_INTERVAL_MINUTES) * 60 * 1000000) / (OT_BUCKET_COUNT))
enum { OT_SYNC_PEER4, OT_SYNC_PEER6 };
enum { FLAG_SERVERSOCKET = 1 };
/* For incoming packets */
static int64 g_socket_in = -1;
static uint8_t g_inbuffer[LIVESYNC_INCOMING_BUFFSIZE];
/* For outgoing packets */
static int64 g_socket_out = -1;
static uint8_t g_peerbuffer_start[LIVESYNC_OUTGOING_BUFFSIZE_PEERS];
static uint8_t *g_peerbuffer_pos;
static uint8_t *g_peerbuffer_highwater = g_peerbuffer_start + LIVESYNC_OUTGOING_BUFFSIZE_PEERS - LIVESYNC_OUTGOING_WATERMARK_PEERS;
static ot_time g_next_packet_time;
static void *livesync_worker(void *args);
static void *streamsync_worker(void *args);
static void livesync_proxytell(uint8_t prefix, uint8_t *info_hash, uint8_t *peer);
void exerr(char *message) {
fprintf(stderr, "%s\n", message);
exit(111);
}
void stats_issue_event(ot_status_event event, PROTO_FLAG proto, uintptr_t event_data) {
(void)event;
(void)proto;
(void)event_data;
}
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);
}
size_t add_peer_to_torrent_proxy(ot_hash hash, ot_peer *peer, size_t peer_size) {
int exactmatch;
ot_torrent *torrent;
ot_peerlist *peer_list;
ot_peer *peer_dest;
ot_vector *torrents_list = mutex_bucket_lock_by_hash(hash);
size_t compare_size = OT_PEER_COMPARE_SIZE_FROM_PEER_SIZE(peer_size);
torrent = vector_find_or_insert(torrents_list, (void *)hash, sizeof(ot_torrent), 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_list6 = malloc(sizeof(ot_peerlist))) || !(torrent->peer_list4 = malloc(sizeof(ot_peerlist)))) {
vector_remove_torrent(torrents_list, torrent);
mutex_bucket_unlock_by_hash(hash, 0);
return -1;
}
byte_zero(torrent->peer_list6, sizeof(ot_peerlist));
byte_zero(torrent->peer_list4, sizeof(ot_peerlist));
}
peer_list = peer_size == OT_PEER_SIZE6 ? torrent->peer_list6 : torrent->peer_list4;
/* Check for peer in torrent */
peer_dest = vector_find_or_insert_peer(&(peer_list->peers), peer, peer_size, &exactmatch);
if (!peer_dest) {
mutex_bucket_unlock_by_hash(hash, 0);
return -1;
}
/* Tell peer that it's fresh */
OT_PEERTIME(peer, peer_size) = 0;
/* If we hadn't had a match create peer there */
if (!exactmatch) {
peer_list->peer_count++;
if (OT_PEERFLAG_D(peer, peer_size) & PEER_FLAG_SEEDING)
peer_list->seed_count++;
}
memcpy(peer_dest, peer, peer_size);
mutex_bucket_unlock_by_hash(hash, 0);
return 0;
}
size_t remove_peer_from_torrent_proxy(ot_hash hash, ot_peer *peer, size_t peer_size) {
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 = peer_list = peer_size == OT_PEER_SIZE6 ? torrent->peer_list6 : torrent->peer_list4;
switch (vector_remove_peer(&peer_list->peers, peer, peer_size)) {
case 2:
peer_list->seed_count--; /* Intentional fallthrough */
case 1:
peer_list->peer_count--; /* Intentional fallthrough */
default:
break;
}
}
mutex_bucket_unlock_by_hash(hash, 0);
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, size_t peer_size) {
int off = sizeof(g_tracker_id) + sizeof(uint32_t);
fprintf(stderr, ".");
while ((ssize_t)(off + sizeof(ot_hash) + peer_size) <= datalen) {
ot_peer *peer = (ot_peer *)(g_inbuffer + off + sizeof(ot_hash));
ot_hash *hash = (ot_hash *)(g_inbuffer + off);
if (OT_PEERFLAG_D(peer, peer_size) & PEER_FLAG_STOPPED)
remove_peer_from_torrent_proxy(*hash, peer, peer_size);
else
add_peer_to_torrent_proxy(*hash, peer, peer_size);
off += sizeof(ot_hash) + peer_size;
}
}
int usage(char *self) {
fprintf(stderr, "Usage: %s -L <livesync_iface_ip> -l <listenip>:<listenport> -c <connectip>:<connectport>\n", self);
return 0;
}
enum {
FLAG_OUTGOING = 0x80,
FLAG_DISCONNECTED = 0x00,
FLAG_CONNECTING = 0x01,
FLAG_WAITTRACKERID = 0x02,
FLAG_CONNECTED = 0x03,
FLAG_MASK = 0x07
};
#define PROXYPEER_NEEDSCONNECT(flag) ((flag) == FLAG_OUTGOING)
#define PROXYPEER_ISCONNECTED(flag) (((flag) & FLAG_MASK) == FLAG_CONNECTED)
#define PROXYPEER_SETDISCONNECTED(flag) (flag) = (((flag) & FLAG_OUTGOING) | FLAG_DISCONNECTED)
#define PROXYPEER_SETCONNECTING(flag) (flag) = (((flag) & FLAG_OUTGOING) | FLAG_CONNECTING)
#define PROXYPEER_SETWAITTRACKERID(flag) (flag) = (((flag) & FLAG_OUTGOING) | FLAG_WAITTRACKERID)
#define PROXYPEER_SETCONNECTED(flag) (flag) = (((flag) & FLAG_OUTGOING) | FLAG_CONNECTED)
typedef struct {
int state; /* Whether we want to connect, how far our handshake is, etc. */
ot_ip6 ip; /* The peer to connect to */
uint16_t port; /* The peers port */
uint8_t indata[8192 * 16]; /* Any data not processed yet */
size_t indata_length; /* Length of unprocessed data */
uint32_t tracker_id; /* How the other end greeted */
int64 fd; /* A file handle, if connected, <= 0 is disconnected (0 initially, -1 else) */
io_batch outdata; /* The iobatch containing our sync data */
size_t packet_tcount; /* Number of unprocessed torrents in packet we currently receive */
uint8_t packet_tprefix; /* Prefix byte for all torrents in current packet */
uint8_t packet_type; /* Type of current packet */
uint32_t packet_tid; /* Tracker id for current packet */
} proxy_peer;
static void process_indata(proxy_peer *peer);
void reset_info_block(proxy_peer *peer) {
peer->indata_length = 0;
peer->tracker_id = 0;
peer->fd = -1;
peer->packet_tcount = 0;
iob_reset(&peer->outdata);
PROXYPEER_SETDISCONNECTED(peer->state);
}
/* Number of connections to peers
* If a peer's IP is set, we try to reconnect, when the connection drops
* If we already have a connected tracker_id in our records for an _incoming_ connection, drop it
* Multiple connections to/from the same ip are okay, if tracker_id doesn't match
* Reconnect attempts occur only twice a minute
*/
static int g_connection_count;
static ot_time g_connection_reconn;
static proxy_peer g_connections[MAX_PEERS];
static void handle_reconnects(void) {
int i;
for (i = 0; i < g_connection_count; ++i)
if (PROXYPEER_NEEDSCONNECT(g_connections[i].state)) {
int64 newfd = socket_tcp6();
fprintf(stderr, "(Re)connecting to peer...");
if (newfd < 0)
continue; /* No socket for you */
io_fd(newfd);
if (socket_bind6_reuse(newfd, g_serverip, g_serverport, 0)) {
io_close(newfd);
continue;
}
if (socket_connect6(newfd, g_connections[i].ip, g_connections[i].port, 0) == -1 && errno != EINPROGRESS && errno != EWOULDBLOCK) {
close(newfd);
continue;
}
io_wantwrite(newfd); /* So we will be informed when it is connected */
io_setcookie(newfd, g_connections + i);
/* Prepare connection info block */
reset_info_block(g_connections + i);
g_connections[i].fd = newfd;
PROXYPEER_SETCONNECTING(g_connections[i].state);
}
g_connection_reconn = time(NULL) + 30;
}
/* Handle incoming connection requests, check against whitelist */
static void handle_accept(int64 serversocket) {
int64 newfd;
ot_ip6 ip;
uint16 port;
while ((newfd = socket_accept6(serversocket, ip, &port, NULL)) != -1) {
/* XXX some access control */
/* Put fd into a non-blocking mode */
io_nonblock(newfd);
if (!io_fd(newfd))
io_close(newfd);
else {
/* Find a new home for our incoming connection */
int i;
for (i = 0; i < MAX_PEERS; ++i)
if (g_connections[i].state == FLAG_DISCONNECTED)
break;
if (i == MAX_PEERS) {
fprintf(stderr, "No room for incoming connection.");
close(newfd);
continue;
}
/* Prepare connection info block */
reset_info_block(g_connections + i);
PROXYPEER_SETCONNECTING(g_connections[i].state);
g_connections[i].port = port;
g_connections[i].fd = newfd;
io_setcookie(newfd, g_connections + i);
/* We expect the connecting side to begin with its tracker_id */
io_wantread(newfd);
}
}
return;
}
/* New sync data on the stream */
static void handle_read(int64 peersocket) {
int i;
int64 datalen;
uint32_t tracker_id;
proxy_peer *peer = io_getcookie(peersocket);
if (!peer) {
/* Can't happen ;) */
io_close(peersocket);
return;
}
switch (peer->state & FLAG_MASK) {
case FLAG_DISCONNECTED:
io_close(peersocket);
break; /* Shouldnt happen */
case FLAG_CONNECTING:
case FLAG_WAITTRACKERID:
/* We want at least the first four bytes to come at once, to avoid keeping extra states (for now)
This also catches 0 bytes reads == EOF and negative values, denoting connection errors */
if (io_tryread(peersocket, (void *)&tracker_id, sizeof(tracker_id)) != sizeof(tracker_id))
goto close_socket;
/* See, if we already have a connection to that peer */
for (i = 0; i < MAX_PEERS; ++i)
if ((g_connections[i].state & FLAG_MASK) == FLAG_CONNECTED && g_connections[i].tracker_id == tracker_id) {
fprintf(stderr, "Peer already connected. Closing connection.\n");
goto close_socket;
}
/* Also no need for soliloquy */
if (tracker_id == g_tracker_id)
goto close_socket;
/* The new connection is good, send our tracker_id on incoming connections */
if (peer->state == FLAG_CONNECTING)
if (io_trywrite(peersocket, (void *)&g_tracker_id, sizeof(g_tracker_id)) != sizeof(g_tracker_id))
goto close_socket;
peer->tracker_id = tracker_id;
PROXYPEER_SETCONNECTED(peer->state);
if (peer->state & FLAG_OUTGOING)
fprintf(stderr, "succeeded.\n");
else
fprintf(stderr, "Incoming connection successful.\n");
break;
close_socket:
fprintf(stderr, "Handshake incomplete, closing socket\n");
io_close(peersocket);
reset_info_block(peer);
break;
case FLAG_CONNECTED:
/* Here we acutally expect data from peer
indata_length should be less than 20+256*7 bytes, for incomplete torrent entries */
datalen = io_tryread(peersocket, (void *)(peer->indata + peer->indata_length), sizeof(peer->indata) - peer->indata_length);
if (!datalen || datalen < -1) {
fprintf(stderr, "Connection closed by remote peer.\n");
io_close(peersocket);
reset_info_block(peer);
} else if (datalen > 0) {
peer->indata_length += datalen;
process_indata(peer);
}
break;
}
}
/* Can write new sync data to the stream */
static void handle_write(int64 peersocket) {
proxy_peer *peer = io_getcookie(peersocket);
if (!peer) {
/* Can't happen ;) */
io_close(peersocket);
return;
}
switch (peer->state & FLAG_MASK) {
case FLAG_DISCONNECTED:
default: /* Should not happen */
io_close(peersocket);
break;
case FLAG_CONNECTING:
/* Ensure that the connection is established and handle connection error */
if (peer->state & FLAG_OUTGOING && !socket_connected(peersocket)) {
fprintf(stderr, "failed\n");
reset_info_block(peer);
io_close(peersocket);
break;
}
if (io_trywrite(peersocket, (void *)&g_tracker_id, sizeof(g_tracker_id)) == sizeof(g_tracker_id)) {
PROXYPEER_SETWAITTRACKERID(peer->state);
io_dontwantwrite(peersocket);
io_wantread(peersocket);
} else {
fprintf(stderr, "Handshake incomplete, closing socket\n");
io_close(peersocket);
reset_info_block(peer);
}
break;
case FLAG_CONNECTED:
switch (iob_send(peersocket, &peer->outdata)) {
case 0: /* all data sent */
io_dontwantwrite(peersocket);
break;
case -3: /* an error occured */
io_close(peersocket);
reset_info_block(peer);
break;
default: /* Normal operation or eagain */
break;
}
break;
}
return;
}
static void server_mainloop() {
int64 sock;
/* inlined livesync_init() */
memset(g_peerbuffer_start, 0, sizeof(g_peerbuffer_start));
g_peerbuffer_pos = g_peerbuffer_start;
memcpy(g_peerbuffer_pos, &g_tracker_id, sizeof(g_tracker_id));
uint32_pack_big((char *)g_peerbuffer_pos + sizeof(g_tracker_id), OT_SYNC_PEER);
g_peerbuffer_pos += sizeof(g_tracker_id) + sizeof(uint32_t);
g_next_packet_time = time(NULL) + LIVESYNC_MAXDELAY;
while (1) {
/* See if we need to connect to anyone */
if (time(NULL) > g_connection_reconn)
handle_reconnects();
/* Wait for io events until next approx reconn check time */
io_waituntil2(30 * 1000);
/* Loop over readable sockets */
while ((sock = io_canread()) != -1) {
const void *cookie = io_getcookie(sock);
if ((uintptr_t)cookie == FLAG_SERVERSOCKET)
handle_accept(sock);
else
handle_read(sock);
}
/* Loop over writable sockets */
while ((sock = io_canwrite()) != -1)
handle_write(sock);
livesync_ticker();
}
}
static void panic(const char *routine) {
fprintf(stderr, "%s: %s\n", routine, strerror(errno));
exit(111);
}
static int64_t ot_try_bind(ot_ip6 ip, uint16_t port) {
int64 sock = socket_tcp6();
if (socket_bind6_reuse(sock, ip, port, 0) == -1)
panic("socket_bind6_reuse");
if (socket_listen(sock, SOMAXCONN) == -1)
panic("socket_listen");
if (!io_fd(sock))
panic("io_fd");
io_setcookie(sock, (void *)FLAG_SERVERSOCKET);
io_wantread(sock);
return sock;
}
static int scan_ip6_port(const char *src, ot_ip6 ip, uint16 *port) {
const char *s = src;
int off, bracket = 0;
while (isspace(*s))
++s;
if (*s == '[')
++s, ++bracket; /* for v6 style notation */
if (!(off = scan_ip6(s, ip)))
return 0;
s += off;
if (*s == 0 || isspace(*s))
return s - src;
if (*s == ']' && bracket)
++s;
if (!ip6_isv4mapped(ip)) {
if ((bracket && *(s) != ':') || (*(s) != '.'))
return 0;
s++;
} else {
if (*(s++) != ':')
return 0;
}
if (!(off = scan_ushort(s, port)))
return 0;
return off + s - src;
}
int main(int argc, char **argv) {
static pthread_t sync_in_thread_id;
static pthread_t sync_out_thread_id;
ot_ip6 serverip;
uint16_t tmpport;
int scanon = 1, lbound = 0, sbound = 0;
srandom(time(NULL));
#ifdef WANT_ARC4RANDOM
g_tracker_id = arc4random();
#else
g_tracker_id = random();
#endif
while (scanon) {
switch (getopt(argc, argv, ":l:c:L:h")) {
case -1:
scanon = 0;
break;
case 'l':
tmpport = 0;
if (!scan_ip6_port(optarg, serverip, &tmpport) || !tmpport) {
usage(argv[0]);
exit(1);
}
ot_try_bind(serverip, tmpport);
++sbound;
break;
case 'c':
if (g_connection_count > MAX_PEERS / 2)
exerr("Connection limit exceeded.\n");
tmpport = 0;
if (!scan_ip6_port(optarg, g_connections[g_connection_count].ip, &g_connections[g_connection_count].port) || !g_connections[g_connection_count].port) {
usage(argv[0]);
exit(1);
}
g_connections[g_connection_count++].state = FLAG_OUTGOING;
break;
case 'L':
tmpport = 9696;
if (!scan_ip6_port(optarg, serverip, &tmpport) || !tmpport) {
usage(argv[0]);
exit(1);
}
livesync_bind_mcast(serverip, tmpport);
++lbound;
break;
default:
case '?':
usage(argv[0]);
exit(1);
}
}
if (!lbound)
exerr("No livesync port bound.");
if (!g_connection_count && !sbound)
exerr("No streamsync port bound.");
pthread_create(&sync_in_thread_id, NULL, livesync_worker, NULL);
pthread_create(&sync_out_thread_id, NULL, streamsync_worker, NULL);
server_mainloop();
return 0;
}
static void *streamsync_worker(void *args) {
(void)args;
while (1) {
int bucket;
/* 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, count_def = 0, count_one = 0, count_two = 0, count_peers = 0;
size_t mem, mem_a = 0, mem_b = 0;
uint8_t *ptr = 0, *ptr_a, *ptr_b, *ptr_c;
if (!torrents_list->size)
goto unlock_continue;
/* 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;
switch (peer_list->peer_count) {
case 2:
count_two++;
break;
case 1:
count_one++;
break;
case 0:
break;
default:
count_def++;
count_peers += peer_list->peer_count;
}
}
/* Maximal memory requirement: max 3 blocks, max torrents * 20 + max peers * 7 */
mem = 3 * (1 + 1 + 2) + (count_one + count_two) * (19 + 1) + count_def * (19 + 8) + (count_one + 2 * count_two + count_peers) * 7;
fprintf(stderr, "Mem: %zd\n", mem);
ptr = ptr_a = ptr_b = ptr_c = malloc(mem);
if (!ptr)
goto unlock_continue;
if (count_one > 4 || !count_def) {
mem_a = 1 + 1 + 2 + count_one * (19 + 7);
ptr_b += mem_a;
ptr_c += mem_a;
ptr_a[0] = 1; /* Offset 0: packet type 1 */
ptr_a[1] = (bucket << 8) >> OT_BUCKET_COUNT_BITS; /* Offset 1: the shared prefix */
ptr_a[2] = count_one >> 8;
ptr_a[3] = count_one & 255;
ptr_a += 4;
} else
count_def += count_one;
if (count_two > 4 || !count_def) {
mem_b = 1 + 1 + 2 + count_two * (19 + 14);
ptr_c += mem_b;
ptr_b[0] = 2; /* Offset 0: packet type 2 */
ptr_b[1] = (bucket << 8) >> OT_BUCKET_COUNT_BITS; /* Offset 1: the shared prefix */
ptr_b[2] = count_two >> 8;
ptr_b[3] = count_two & 255;
ptr_b += 4;
} else
count_def += count_two;
if (count_def) {
ptr_c[0] = 0; /* Offset 0: packet type 0 */
ptr_c[1] = (bucket << 8) >> OT_BUCKET_COUNT_BITS; /* Offset 1: the shared prefix */
ptr_c[2] = count_def >> 8;
ptr_c[3] = count_def & 255;
ptr_c += 4;
}
/* For each torrent in this bucket.. */
for (tor_offset = 0; tor_offset < torrents_list->size; ++tor_offset) {
/* Address torrents members */
ot_torrent *torrent = ((ot_torrent *)(torrents_list->data)) + tor_offset;
ot_peerlist *peer_list = torrent->peer_list;
ot_peer *peers = (ot_peer *)(peer_list->peers.data);
uint8_t **dst;
/* Determine destination slot */
count_peers = peer_list->peer_count;
switch (count_peers) {
case 0:
continue;
case 1:
dst = mem_a ? &ptr_a : &ptr_c;
break;
case 2:
dst = mem_b ? &ptr_b : &ptr_c;
break;
default:
dst = &ptr_c;
break;
}
/* Copy tail of info_hash, advance pointer */
memcpy(*dst, ((uint8_t *)torrent->hash) + 1, sizeof(ot_hash) - 1);
*dst += sizeof(ot_hash) - 1;
/* Encode peer count */
if (dst == &ptr_c)
while (count_peers) {
if (count_peers <= 0x7f)
*(*dst)++ = count_peers;
else
*(*dst)++ = 0x80 | (count_peers & 0x7f);
count_peers >>= 7;
}
/* Copy peers */
count_peers = peer_list->peer_count;
while (count_peers--) {
memcpy(*dst, peers++, OT_IP_SIZE + 3);
*dst += OT_IP_SIZE + 3;
}
free_peerlist(peer_list);
}
free(torrents_list->data);
memset(torrents_list, 0, sizeof(*torrents_list));
unlock_continue:
mutex_bucket_unlock(bucket, 0);
if (ptr) {
int i;
if (ptr_b > ptr_c)
ptr_c = ptr_b;
if (ptr_a > ptr_c)
ptr_c = ptr_a;
mem = ptr_c - ptr;
for (i = 0; i < MAX_PEERS; ++i) {
if (PROXYPEER_ISCONNECTED(g_connections[i].state)) {
void *tmp = malloc(mem);
if (tmp) {
memcpy(tmp, ptr, mem);
iob_addbuf_free(&g_connections[i].outdata, tmp, mem);
io_wantwrite(g_connections[i].fd);
}
}
}
free(ptr);
}
usleep(OT_SYNC_SLEEP);
}
}
return 0;
}
static void livesync_issue_peersync() {
socket_send4(g_socket_out, (char *)g_peerbuffer_start, g_peerbuffer_pos - g_peerbuffer_start, groupip_1, LIVESYNC_PORT);
g_peerbuffer_pos = g_peerbuffer_start + sizeof(g_tracker_id) + sizeof(uint32_t);
g_next_packet_time = time(NULL) + LIVESYNC_MAXDELAY;
}
void livesync_ticker() {
/* livesync_issue_peersync sets g_next_packet_time */
if (time(NULL) > g_next_packet_time && g_peerbuffer_pos > g_peerbuffer_start + sizeof(g_tracker_id))
livesync_issue_peersync();
}
static void livesync_proxytell(uint8_t prefix, uint8_t *info_hash, uint8_t *peer) {
// unsigned int i;
*g_peerbuffer_pos = prefix;
memcpy(g_peerbuffer_pos + 1, info_hash, sizeof(ot_hash) - 1);
memcpy(g_peerbuffer_pos + sizeof(ot_hash), peer, sizeof(ot_peer) - 1);
#if 0
/* Dump info_hash */
for( i=0; i<sizeof(ot_hash); ++i )
printf( "%02X", g_peerbuffer_pos[i] );
putchar( ':' );
#endif
g_peerbuffer_pos += sizeof(ot_hash);
#if 0
printf( "%hhu.%hhu.%hhu.%hhu:%hu (%02X %02X)\n", g_peerbuffer_pos[0], g_peerbuffer_pos[1], g_peerbuffer_pos[2], g_peerbuffer_pos[3],
g_peerbuffer_pos[4] | ( g_peerbuffer_pos[5] << 8 ), g_peerbuffer_pos[6], g_peerbuffer_pos[7] );
#endif
g_peerbuffer_pos += sizeof(ot_peer);
if (g_peerbuffer_pos >= g_peerbuffer_highwater)
livesync_issue_peersync();
}
static void process_indata(proxy_peer *peer) {
size_t consumed, peers;
uint8_t *data = peer->indata, *hash;
uint8_t *dataend = data + peer->indata_length;
while (1) {
/* If we're not inside of a packet, make a new one */
if (!peer->packet_tcount) {
/* Ensure the header is complete or postpone processing */
if (data + 4 > dataend)
break;
peer->packet_type = data[0];
peer->packet_tprefix = data[1];
peer->packet_tcount = data[2] * 256 + data[3];
data += 4;
printf("type: %hhu, prefix: %02X, torrentcount: %zd\n", peer->packet_type, peer->packet_tprefix, peer->packet_tcount);
}
/* Ensure size for a minimal torrent block */
if (data + sizeof(ot_hash) + OT_IP_SIZE + 3 > dataend)
break;
/* Advance pointer to peer count or peers */
hash = data;
data += sizeof(ot_hash) - 1;
/* Type 0 has peer count encoded before each peers */
peers = peer->packet_type;
if (!peers) {
int shift = 0;
do
peers |= (0x7f & *data) << (7 * shift);
while (*(data++) & 0x80 && shift++ < 6);
}
#if 0
printf( "peers: %zd\n", peers );
#endif
/* Ensure enough data being read to hold all peers */
if (data + (OT_IP_SIZE + 3) * peers > dataend) {
data = hash;
break;
}
while (peers--) {
livesync_proxytell(peer->packet_tprefix, hash, data);
data += OT_IP_SIZE + 3;
}
--peer->packet_tcount;
}
consumed = data - peer->indata;
memmove(peer->indata, data, peer->indata_length - consumed);
peer->indata_length -= consumed;
}
static void *livesync_worker(void *args) {
(void)args;
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((char *)g_inbuffer + sizeof(g_tracker_id))) {
case OT_SYNC_PEER4:
livesync_handle_peersync(datalen, OT_PEER_SIZE4);
break;
case OT_SYNC_PEER6:
livesync_handle_peersync(datalen, OT_PEER_SIZE6);
break;
default:
// fprintf( stderr, "Received an unknown live sync packet type %u.\n", uint32_read_big( sizeof( g_tracker_id ) + (char*)g_inbuffer ) );
break;
}
}
return 0;
}