libcody/netclient.cc

   1 // CODYlib              -*- mode:c++ -*-
   2 // Copyright (C) 2020 Nathan Sidwell, nathan@acm.org
   3 // License: Apache v2.0
   4
   5 // Cody
   6 #include "internal.hh"
   7
   8 #if CODY_NETWORKING
   9 // C
  10 #include <cerrno>
  11 #include <cstring>
  12 // OS
  13 #include <netdb.h>
  14 #include <unistd.h>
  15 #include <arpa/inet.h>
  16 #include <netinet/in.h>
  17 #include <sys/un.h>
  18
  19 #ifndef AI_NUMERICSERV
  20 #define AI_NUMERICSERV 0
  21 #endif
  22
  23 // Client-side networking helpers
  24
  25 namespace Cody {
  26
  27 int OpenSocket (char const **e, sockaddr const *addr, socklen_t len)
  28 {
  29   char const *errstr = nullptr;
  30
  31   int fd = socket (addr->sa_family, SOCK_STREAM, 0);
  32   if (fd < 0)
  33     {
  34       errstr = "creating socket";
  35
  36     fail:;
  37       int err = errno;
  38       if (e)
  39         *e = errstr;
  40       if (fd >= 0)
  41         close (fd);
  42       errno = err;
  43       return -1;
  44     }
  45
  46   if (connect (fd, addr, len) < 0)
  47     {
  48       errstr = "connecting socket";
  49       goto fail;
  50     }
  51
  52   return fd;
  53 }
  54
  55 int OpenLocal (char const **e, char const *name)
  56 {
  57   sockaddr_un addr;
  58   size_t len = strlen (name);
  59
  60   if (len >= sizeof (addr.sun_path))
  61     {
  62       errno = ENAMETOOLONG;
  63       return -1;
  64     }
  65
  66   memset (&addr, 0, offsetof (sockaddr_un, sun_path));
  67   addr.sun_family = AF_UNIX;
  68   memcpy (addr.sun_path, name, len + 1);
  69   return OpenSocket (e, (sockaddr *)&addr, sizeof (addr));
  70 }
  71
  72 int OpenInet6 (char const **e, char const *name, int port)
  73 {
  74   addrinfo *addrs = nullptr;
  75   int fd = -1;
  76   char const *errstr = nullptr;
  77
  78   fd = socket (AF_INET6, SOCK_STREAM, 0);
  79   if (fd < 0)
  80     {
  81       errstr = "socket";
  82
  83     fail:;
  84       int err = errno;
  85       if (e)
  86         *e = errstr;
  87       if (fd >= 0)
  88         close (fd);
  89       if (addrs)
  90         freeaddrinfo (addrs);
  91       errno = err;
  92       return -1;
  93     }
  94
  95   addrinfo hints;
  96   hints.ai_flags = AI_NUMERICSERV;
  97   hints.ai_family = AF_INET6;
  98   hints.ai_socktype = SOCK_STREAM;
  99   hints.ai_protocol = 0;
 100   hints.ai_addrlen = 0;
 101   hints.ai_addr = nullptr;
 102   hints.ai_canonname = nullptr;
 103   hints.ai_next = nullptr;
 104
 105   /* getaddrinfo requires a port number, but is quite happy to accept
 106      invalid ones.  So don't rely on it.  */
 107   if (int err = getaddrinfo (name, "0", &hints, &addrs))
 108     {
 109       errstr = gai_strerror (err);
 110       // What's the best errno to set?
 111       errno = 0;
 112       goto fail;
 113     }
 114
 115   sockaddr_in6 addr;
 116   memset (&addr, 0, sizeof (addr));
 117   addr.sin6_family = AF_INET6;
 118
 119   for (struct addrinfo *next = addrs; next; next = next->ai_next)
 120     if (next->ai_family == AF_INET6
 121         && next->ai_socktype == SOCK_STREAM)
 122       {
 123         sockaddr_in6 *in6 = (sockaddr_in6 *)next->ai_addr;
 124         in6->sin6_port = htons (port);
 125         if (ntohs (in6->sin6_port) != port)
 126           errno = EINVAL;
 127         else if (!connect (fd, next->ai_addr, next->ai_addrlen))
 128           goto done;
 129       }
 130   errstr = "connecting";
 131   goto fail;
 132
 133  done:;
 134   freeaddrinfo (addrs);
 135
 136   return fd;
 137 }
 138
 139 }
 140
 141 #endif