release/src/router/transmission/libtransmission/tr-utp.c

   1 /*
   2 Copyright (c) 2010 by Juliusz Chroboczek
   3
   4 Permission is hereby granted, free of charge, to any person obtaining a copy
   5 of this software and associated documentation files (the "Software"), to deal
   6 in the Software without restriction, including without limitation the rights
   7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8 copies of the Software, and to permit persons to whom the Software is
   9 furnished to do so, subject to the following conditions:
  10
  11 The above copyright notice and this permission notice shall be included in
  12 all copies or substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20 THE SOFTWARE.
  21
  22 */
  23
  24 #include <assert.h>
  25
  26 #include <event2/event.h>
  27
  28 #include "transmission.h"
  29 #include "net.h"
  30 #include "session.h"
  31 #include "crypto.h" /* tr_cryptoWeakRandInt() */
  32 #include "peer-mgr.h"
  33 #include "tr-utp.h"
  34 #include "utils.h"
  35
  36 #define MY_NAME "UTP"
  37
  38 #define dbgmsg( ... ) \
  39     do { \
  40         if( tr_deepLoggingIsActive( ) ) \
  41             tr_deepLog( __FILE__, __LINE__, MY_NAME, __VA_ARGS__ ); \
  42     } while( 0 )
  43
  44 #ifndef WITH_UTP
  45
  46 void
  47 UTP_Close(struct UTPSocket * socket)
  48 {
  49     tr_nerr( MY_NAME, "UTP_Close(%p) was called.", socket );
  50     dbgmsg( "UTP_Close(%p) was called.", socket );
  51     assert( 0 ); /* FIXME: this is too much for the long term, but probably needed in the short term */
  52 }
  53
  54 void
  55 UTP_RBDrained(struct UTPSocket *socket)
  56 {
  57     tr_nerr( MY_NAME, "UTP_RBDrained(%p) was called.", socket );
  58     dbgmsg( "UTP_RBDrained(%p) was called.", socket );
  59     assert( 0 ); /* FIXME: this is too much for the long term, but probably needed in the short term */
  60 }
  61
  62 bool
  63 UTP_Write(struct UTPSocket *socket, size_t count)
  64 {
  65     tr_nerr( MY_NAME, "UTP_RBDrained(%p, %zu) was called.", socket, count );
  66     dbgmsg( "UTP_RBDrained(%p, %zu) was called.", socket, count );
  67     assert( 0 ); /* FIXME: this is too much for the long term, but probably needed in the short term */
  68     return false;
  69 }
  70
  71 int tr_utpPacket(const unsigned char *buf UNUSED, size_t buflen UNUSED,
  72                  const struct sockaddr *from UNUSED, socklen_t fromlen UNUSED,
  73                  tr_session *ss UNUSED) { return -1; }
  74
  75 struct UTPSocket *UTP_Create(SendToProc *send_to_proc UNUSED,
  76                              void *send_to_userdata UNUSED,
  77                              const struct sockaddr *addr UNUSED,
  78                              socklen_t addrlen UNUSED)
  79 {
  80     errno = ENOSYS;
  81     return NULL;
  82 }
  83
  84 void tr_utpClose( tr_session * ss UNUSED ) { }
  85
  86 void tr_utpSendTo(void *closure UNUSED,
  87                   const unsigned char *buf UNUSED, size_t buflen UNUSED,
  88                   const struct sockaddr *to UNUSED, socklen_t tolen UNUSED) { }
  89
  90 #else
  91
  92 /* Greg says 50ms works for them. */
  93
  94 #define UTP_INTERVAL_US 50000
  95
  96 static struct event *utp_timer = NULL;
  97
  98 static void
  99 incoming(void *closure, struct UTPSocket *s)
 100 {
 101     tr_session *ss = closure;
 102     struct sockaddr_storage from_storage;
 103     struct sockaddr *from = (struct sockaddr*)&from_storage;
 104     socklen_t fromlen = sizeof(from_storage);
 105     tr_address addr;
 106     tr_port port;
 107
 108     if( !tr_sessionIsUTPEnabled(ss) ) {
 109         UTP_Close(s);
 110         return;
 111     }
 112
 113     UTP_GetPeerName(s, from, &fromlen);
 114     if( !tr_address_from_sockaddr_storage( &addr, &port, &from_storage ) )
 115     {
 116         tr_nerr("UTP", "Unknown socket family");
 117         UTP_Close(s);
 118         return;
 119     }
 120
 121     tr_peerMgrAddIncoming(ss->peerMgr, &addr, port, -1, s);
 122 }
 123
 124 void
 125 tr_utpSendTo(void *closure, const unsigned char *buf, size_t buflen,
 126              const struct sockaddr *to, socklen_t tolen)
 127 {
 128     tr_session *ss = closure;
 129
 130     if(to->sa_family == AF_INET && ss->udp_socket)
 131         sendto(ss->udp_socket, buf, buflen, 0, to, tolen);
 132     else if(to->sa_family == AF_INET6 && ss->udp_socket)
 133         sendto(ss->udp6_socket, buf, buflen, 0, to, tolen);
 134 }
 135
 136 static void
 137 reset_timer(tr_session *ss)
 138 {
 139     int sec;
 140     int usec;
 141     if( tr_sessionIsUTPEnabled( ss ) ) {
 142         sec = 0;
 143         usec = UTP_INTERVAL_US / 2 + tr_cryptoWeakRandInt(UTP_INTERVAL_US);
 144     } else {
 145         /* If somebody has disabled uTP, then we still want to run
 146            UTP_CheckTimeouts, in order to let closed sockets finish
 147            gracefully and so on.  However, since we're not particularly
 148            interested in that happening in a timely manner, we might as
 149            well use a large timeout. */
 150         sec = 2;
 151         usec = tr_cryptoWeakRandInt( 1000000 );
 152     }
 153     tr_timerAdd( utp_timer, sec, usec );
 154 }
 155
 156 static void
 157 timer_callback(int s UNUSED, short type UNUSED, void *closure)
 158 {
 159     tr_session *ss = closure;
 160     UTP_CheckTimeouts();
 161     reset_timer( ss );
 162 }
 163
 164 int
 165 tr_utpPacket(const unsigned char *buf, size_t buflen,
 166              const struct sockaddr *from, socklen_t fromlen,
 167              tr_session *ss)
 168 {
 169     if( !ss->isClosed && !utp_timer )
 170     {
 171         utp_timer = evtimer_new( ss->event_base, timer_callback, ss );
 172         if(utp_timer == NULL)
 173             return -1;
 174         reset_timer( ss );
 175     }
 176
 177     return UTP_IsIncomingUTP(incoming, tr_utpSendTo, ss,
 178                              buf, buflen, from, fromlen);
 179 }
 180
 181 void
 182 tr_utpClose( tr_session * session UNUSED )
 183 {
 184     if( utp_timer )
 185     {
 186         evtimer_del( utp_timer );
 187         utp_timer = NULL;
 188     }
 189 }
 190
 191 #endif /* #ifndef WITH_UTP ... else */