xapian-core/common/socket_utils.cc

   1 /** @file  socket_utils.cc
   2  *  @brief Socket handling utilities.
   3  */
   4 /* Copyright (C) 2006,2007,2008,2015 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include <config.h>
  22 #include "socket_utils.h"
  23
  24 #include <limits>
  25
  26 #include "realtime.h"
  27 #include "safesyssocket.h"
  28
  29 using namespace std;
  30
  31 #include <arpa/inet.h>
  32 #include "stringutils.h"
  33
  34 #ifdef __WIN32__
  35 # include <io.h>
  36 # include "msvcignoreinvalidparam.h"
  37 # include <cerrno>
  38
  39 /// Convert an fd (which might be a socket) to a WIN32 HANDLE.
  40 extern HANDLE fd_to_handle(int fd) {
  41     MSVCIgnoreInvalidParameter invalid_handle_value_is_ok;
  42     HANDLE handle = (HANDLE)_get_osfhandle(fd);
  43     if (handle != INVALID_HANDLE_VALUE) return handle;
  44     // On WIN32, a socket fd isn't the same as a non-socket fd - in fact it's
  45     // already a HANDLE!
  46     return reinterpret_cast<HANDLE>(fd);
  47 }
  48
  49 /// Close an fd, which might be a socket.
  50 extern void close_fd_or_socket(int fd) {
  51     MSVCIgnoreInvalidParameter invalid_fd_value_is_ok;
  52     if (close(fd) == -1 && errno == EBADF) {
  53         // Bad file descriptor - probably because the fd is actually
  54         // a socket.
  55         closesocket(fd);
  56     }
  57 }
  58
  59 #endif
  60
  61 void
  62 set_socket_timeouts(int fd, double timeout)
  63 {
  64     (void)fd;
  65     (void)timeout;
  66 #if defined SO_SNDTIMEO || defined SO_RCVTIMEO
  67     {
  68 # ifndef __WIN32__
  69         struct timeval t;
  70         RealTime::to_timeval(timeout, &t);
  71 # else
  72         // Just to be different, it's a DWORD counting in milliseconds.
  73         DWORD t;
  74         if (usual(timeout < numeric_limits<DWORD>::max() / 1000))
  75             t = timeout * 1000;
  76         else
  77             t = numeric_limits<DWORD>::max();
  78 # endif
  79 # ifdef SO_SNDTIMEO
  80         (void)setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO,
  81                          reinterpret_cast<char*>(&t), sizeof(t));
  82 # endif
  83 # ifdef SO_RCVTIMEO
  84         (void)setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO,
  85                          reinterpret_cast<char*>(&t), sizeof(t));
  86 # endif
  87     }
  88 #endif
  89 #ifdef SO_KEEPALIVE
  90     // SO_SNDTIMEO and SO_RCVTIMEO may be ignored even if they exist, so set
  91     // SO_KEEPALIVE anyway if it exists, as it will cause stuck connections to
  92     // time out eventually (though it may take ~2 hours).
  93     {
  94 # ifndef __WIN32__
  95         int flag = 1;
  96 # else
  97         DWORD flag = 1;
  98 # endif
  99         (void)setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE,
 100                          reinterpret_cast<char*>(&flag), sizeof(flag));
 101     }
 102 #endif
 103 }
 104
 105 int
 106 pretty_ip6(const void* p, char* buf)
 107 {
 108     const sockaddr_in* a = reinterpret_cast<const sockaddr_in*>(p);
 109     const sockaddr_in6* a6 = reinterpret_cast<const sockaddr_in6*>(p);
 110     sa_family_t af = a6->sin6_family;
 111     in_port_t port;
 112     if (af == AF_INET6) {
 113         port = a6->sin6_port;
 114     } else if (af == AF_INET) {
 115         port = a->sin_port;
 116     } else {
 117         return -1;
 118     }
 119
 120 #ifndef __WIN32__
 121     // Under __WIN32__, inet_ntop()'s second parameter isn't const for some
 122     // reason.  We don't currently use inet_ntop() there, but allow for a
 123     // non-const second parameter in case it's more widespread.
 124     void* src = const_cast<void*>(p);
 125     const char* r = inet_ntop(af, src, buf, PRETTY_IP6_LEN);
 126     if (!r)
 127         return -1;
 128 #else
 129     // inet_ntop() isn't always available, at least with mingw.
 130     // WSAAddressToString() supports both IPv4 and IPv6, so just use that.
 131     DWORD size = PRETTY_IP6_LEN;
 132     if (WSAAddressToString(reinterpret_cast<sockaddr*>(&remote_address),
 133                            sizeof(remote_address), NULL, buf, &size) != 0) {
 134         return -1;
 135     }
 136     const char* r = buf;
 137 #endif
 138
 139     if (startswith(r, "::ffff:") || startswith(r, "::FFFF:")) {
 140         if (strchr(r + 7, '.')) {
 141             r += 7;
 142         }
 143     }
 144
 145     if (r != buf)
 146         memmove(buf, r, strlen(r) + 1);
 147
 148     return port;
 149 }