1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
It is considered beerware. Prost. Skol. Cheers or whatever.
$id$ */
/* System */
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
/* Libowfat */
#include "byte.h"
#include "ip6.h"
#include "ndelay.h"
#include "socket.h"
/* Opentracker */
#include "ot_accesslist.h"
#include "ot_livesync.h"
#include "ot_mutex.h"
#include "ot_stats.h"
#include "trackerlogic.h"
#ifdef WANT_SYNC_LIVE
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))
#define LIVESYNC_MAXDELAY 15 /* seconds */
enum { OT_SYNC_PEER4, OT_SYNC_PEER6 };
/* Forward declaration */
static void *livesync_worker(void *args);
/* For outgoing packets */
static int64 g_socket_in = -1;
/* For incoming packets */
static int64 g_socket_out = -1;
static pthread_mutex_t g_outbuf_mutex = PTHREAD_MUTEX_INITIALIZER;
typedef struct {
uint8_t data[LIVESYNC_OUTGOING_BUFFSIZE_PEERS];
size_t fill;
ot_time next_packet_time;
} sync_buffer;
static sync_buffer g_v6_buf;
static sync_buffer g_v4_buf;
static pthread_t thread_id;
void livesync_init() {
if (g_socket_in == -1)
exerr("No socket address for live sync specified.");
/* Prepare outgoing peers buffer */
memcpy(g_v6_buf.data, &g_tracker_id, sizeof(g_tracker_id));
memcpy(g_v4_buf.data, &g_tracker_id, sizeof(g_tracker_id));
uint32_pack_big((char *)g_v6_buf.data + sizeof(g_tracker_id), OT_SYNC_PEER6);
uint32_pack_big((char *)g_v4_buf.data + sizeof(g_tracker_id), OT_SYNC_PEER4);
g_v6_buf.fill = sizeof(g_tracker_id) + sizeof(uint32_t);
g_v4_buf.fill = sizeof(g_tracker_id) + sizeof(uint32_t);
g_v6_buf.next_packet_time = g_now_seconds + LIVESYNC_MAXDELAY;
g_v4_buf.next_packet_time = g_now_seconds + LIVESYNC_MAXDELAY;
pthread_create(&thread_id, NULL, livesync_worker, NULL);
}
void livesync_deinit() {
if (g_socket_in != -1)
close(g_socket_in);
if (g_socket_out != -1)
close(g_socket_out);
pthread_cancel(thread_id);
}
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, 0);
}
/* Caller MUST hold g_outbuf_mutex. Returns with g_outbuf_mutex unlocked */
static void livesync_issue_peersync(sync_buffer *buf) {
char mycopy[LIVESYNC_OUTGOING_BUFFSIZE_PEERS];
size_t fill = buf->fill;
memcpy(mycopy, buf->data, fill);
buf->fill = sizeof(g_tracker_id) + sizeof(uint32_t);
buf->next_packet_time = g_now_seconds + LIVESYNC_MAXDELAY;
/* From now this thread has a local copy of the buffer and
has modified the protected element */
pthread_mutex_unlock(&g_outbuf_mutex);
socket_send4(g_socket_out, mycopy, fill, groupip_1, LIVESYNC_PORT);
}
static void livesync_handle_peersync(struct ot_workstruct *ws, size_t peer_size) {
size_t 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 ((ssize_t)(off + sizeof(ot_hash) + peer_size) <= ws->request_size) {
memcpy(&ws->peer, ws->request + off + sizeof(ot_hash), peer_size);
ws->hash = (ot_hash *)(ws->request + off);
if (!g_opentracker_running)
return;
if (OT_PEERFLAG(ws->peer) & PEER_FLAG_STOPPED)
remove_peer_from_torrent(FLAG_MCA, ws);
else
add_peer_to_torrent_and_return_peers(FLAG_MCA, ws, /* amount = */ 0);
off += sizeof(ot_hash) + peer_size;
}
stats_issue_event(EVENT_SYNC, 0, (ws->request_size - sizeof(g_tracker_id) - sizeof(uint32_t)) / ((ssize_t)sizeof(ot_hash) + peer_size));
}
/* Tickle the live sync module from time to time, so no events get
stuck when there's not enough traffic to fill udp packets fast
enough */
void livesync_ticker() {
/* livesync_issue_peersync sets g_next_packet_time */
pthread_mutex_lock(&g_outbuf_mutex);
if (g_now_seconds > g_v6_buf.next_packet_time && g_v6_buf.fill > sizeof(g_tracker_id) + sizeof(uint32_t))
livesync_issue_peersync(&g_v6_buf);
else
pthread_mutex_unlock(&g_outbuf_mutex);
pthread_mutex_lock(&g_outbuf_mutex);
if (g_now_seconds > g_v4_buf.next_packet_time && g_v4_buf.fill > sizeof(g_tracker_id) + sizeof(uint32_t))
livesync_issue_peersync(&g_v4_buf);
else
pthread_mutex_unlock(&g_outbuf_mutex);
}
/* Inform live sync about whats going on. */
void livesync_tell(struct ot_workstruct *ws) {
size_t peer_size; /* initialized in next line */
ot_peer *peer_src = peer_from_peer6(&ws->peer, &peer_size);
sync_buffer *dest_buf = peer_size == OT_PEER_SIZE6 ? &g_v6_buf : &g_v4_buf;
pthread_mutex_lock(&g_outbuf_mutex);
memcpy(dest_buf->data + dest_buf->fill, ws->hash, sizeof(ot_hash));
dest_buf->fill += sizeof(ot_hash);
memcpy(dest_buf->data + dest_buf->fill, peer_src, peer_size);
dest_buf->fill += peer_size;
if (dest_buf->fill >= LIVESYNC_OUTGOING_BUFFSIZE_PEERS - LIVESYNC_OUTGOING_WATERMARK_PEERS)
livesync_issue_peersync(dest_buf);
else
pthread_mutex_unlock(&g_outbuf_mutex);
}
static void *livesync_worker(void *args) {
struct ot_workstruct ws;
ot_ip6 in_ip;
uint16_t in_port;
(void)args;
/* Initialize our "thread local storage" */
ws.inbuf = ws.request = malloc(LIVESYNC_INCOMING_BUFFSIZE);
ws.outbuf = ws.reply = 0;
memcpy(in_ip, V4mappedprefix, sizeof(V4mappedprefix));
while (1) {
ws.request_size = socket_recv4(g_socket_in, (char *)ws.inbuf, LIVESYNC_INCOMING_BUFFSIZE, 12 + (char *)in_ip, &in_port);
/* Expect at least tracker id and packet type */
if (ws.request_size <= (ssize_t)(sizeof(g_tracker_id) + sizeof(uint32_t)))
continue;
if (!accesslist_is_blessed(in_ip, OT_PERMISSION_MAY_LIVESYNC))
continue;
if (!memcmp(ws.inbuf, &g_tracker_id, sizeof(g_tracker_id))) {
/* TODO: log packet coming from ourselves */
continue;
}
switch (uint32_read_big(sizeof(g_tracker_id) + (char *)ws.inbuf)) {
case OT_SYNC_PEER6:
livesync_handle_peersync(&ws, OT_PEER_SIZE6);
break;
case OT_SYNC_PEER4:
livesync_handle_peersync(&ws, OT_PEER_SIZE4);
break;
default:
break;
}
}
/* Never returns. */
return NULL;
}
#endif
|