ipstreams/wvudp.cc

   1 /*
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * WvUDPStream can send and receive packets on a connectionless UDP socket.
   6  * See wvudp.h for details.
   7  */
   8 #include "wvudp.h"
   9
  10 #ifndef WIN32
  11 #include <sys/socket.h>
  12 #else
  13 #define setsockopt(a,b,c,d,e) setsockopt(a,b,c, (const char*) d,e)
  14 #define recvfrom(a,b,c,d,e,f) recvfrom(a, (char *) b, c, d, e, f)
  15 #define sendto(a,b,c,d,e,f) sendto(a,(const char*) b,c,d,e,f)
  16 #undef errno
  17 #define errno GetLastError()
  18 #endif
  19
  20 #include <fcntl.h>
  21
  22 #ifdef ISDARWIN
  23 # define socklen_t int
  24 #endif
  25
  26 WvUDPStream::WvUDPStream(const WvIPPortAddr &_local,
  27     const WvIPPortAddr &_rem) :
  28     localaddr(), remaddr(_rem)
  29 {
  30     int x = 1;
  31     setfd(socket(PF_INET, SOCK_DGRAM, 0));
  32     if (getfd() < 0
  33         || setsockopt(getfd(), SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x)) < 0)
  34     {
  35         seterr(errno);
  36         return;
  37     }
  38
  39     set_close_on_exec(true);
  40     set_nonblock(true);
  41
  42     struct sockaddr *sa = _local.sockaddr();
  43     if (bind(getfd(), sa, _local.sockaddr_len()))
  44     {
  45         delete sa;
  46         seterr(errno);
  47         return;
  48     }
  49     delete sa;
  50
  51     struct sockaddr_in nsa;
  52     socklen_t nsalen = sizeof(nsa);
  53     if (getsockname(getfd(), (sockaddr *)&nsa, &nsalen) < 0)
  54     {
  55         seterr(errno);
  56         return;
  57     }
  58     localaddr = WvIPPortAddr(&nsa);
  59
  60     if (WvIPAddr(_rem) != WvIPAddr())
  61     {
  62         struct sockaddr *sa = _rem.sockaddr();
  63         if (connect(getfd(), sa, _rem.sockaddr_len()))
  64         {
  65             delete sa;
  66             seterr(errno);
  67             return;
  68         }
  69         delete sa;
  70     }
  71 }
  72
  73
  74 WvUDPStream::~WvUDPStream()
  75 {
  76 }
  77
  78
  79 const WvAddr *WvUDPStream::src() const
  80 {
  81     return &remaddr;
  82 }
  83
  84
  85 const WvAddr *WvUDPStream::local() const
  86 {
  87     return &localaddr;
  88 }
  89
  90
  91 size_t WvUDPStream::uread(void *buf, size_t count)
  92 {
  93     if (!isok() || !buf || !count) return 0;
  94
  95     struct sockaddr_in from;
  96     socklen_t fromlen = sizeof(from);
  97     int in = recvfrom(getfd(), buf, count, 0, (sockaddr *)&from, &fromlen);
  98
  99     if (in >= 0)
 100         remaddr = WvIPPortAddr(&from);
 101
 102     // errors in UDP are ignored
 103     return in < 0 ? 0 : in;
 104 }
 105
 106
 107 size_t WvUDPStream::uwrite(const void *buf, size_t count)
 108 {
 109     if (!isok() || !buf || !count) return 0;
 110
 111     // pretend everything worked if there is nowhere to send data
 112     if (remaddr.is_zero()) return count;
 113
 114     struct sockaddr *to = remaddr.sockaddr();
 115     size_t tolen = remaddr.sockaddr_len();
 116     int out;
 117
 118     out = sendto(getfd(), buf, count, 0, to, tolen);
 119
 120     if (out < 0 && errno == EACCES) // permission denied
 121         seterr(EACCES);
 122
 123     delete to;
 124
 125     // errors in UDP are ignored
 126     // pretend that the write always succeeds even if the kernel
 127     // complains since we don't want datagrams backing up in the
 128     // buffer and forming merged datagrams as a result
 129     return out < 0 ? 0 : out;
 130 }
 131
 132
 133 void WvUDPStream::enable_broadcasts()
 134 {
 135     int value = 1;
 136
 137     if (!isok()) return;
 138
 139     setsockopt(getfd(), SOL_SOCKET, SO_BROADCAST, &value, sizeof(value));
 140 }