methods/connect.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: connect.cc,v 1.3 1999/07/18 23:06:56 jgg Exp $
   4 /* ######################################################################
   5
   6    Connect - Replacement connect call
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10 // Include Files                                                        /*{{{*/
  11 #include "connect.h"
  12 #include <apt-pkg/error.h>
  13 #include <apt-pkg/fileutl.h>
  14
  15 #include <stdio.h>
  16 #include <errno.h>
  17 #include <unistd.h>
  18
  19 // Internet stuff
  20 #include <netinet/in.h>
  21 #include <sys/socket.h>
  22 #include <arpa/inet.h>
  23 #include <netdb.h>
  24
  25 #include "rfc2553emu.h"
  26                                                                         /*}}}*/
  27
  28 static string LastHost;
  29 static int LastPort = 0;
  30 static struct addrinfo *LastHostAddr = 0;
  31 static struct addrinfo *LastUsed = 0;
  32
  33 // DoConnect - Attempt a connect operation                              /*{{{*/
  34 // ---------------------------------------------------------------------
  35 /* This helper function attempts a connection to a single address. */
  36 static bool DoConnect(struct addrinfo *Addr,string Host,
  37                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  38 {
  39    // Show a status indicator
  40    char Name[NI_MAXHOST];
  41    Name[0] = 0;
  42    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  43                Name,sizeof(Name),0,0,NI_NUMERICHOST);
  44    Owner->Status("Connecting to %s (%s)",Host.c_str(),Name);
  45
  46    // Get a socket
  47    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  48                     Addr->ai_protocol)) < 0)
  49       return _error->Errno("socket","Could not create a socket");
  50
  51    SetNonBlock(Fd,true);
  52    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  53        errno != EINPROGRESS)
  54       return _error->Errno("connect","Cannot initiate the connection "
  55                            "to %s (%s).",Host.c_str(),Name);
  56
  57    /* This implements a timeout for connect by opening the connection
  58       nonblocking */
  59    if (WaitFd(Fd,true,TimeOut) == false)
  60       return _error->Error("Could not connect to %s (%s), "
  61                            "connection timed out",Host.c_str(),Name);
  62
  63    // Check the socket for an error condition
  64    unsigned int Err;
  65    unsigned int Len = sizeof(Err);
  66    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
  67       return _error->Errno("getsockopt","Failed");
  68
  69    if (Err != 0)
  70       return _error->Error("Could not connect to %s (%s).",Host.c_str(),Name);
  71
  72    return true;
  73 }
  74                                                                         /*}}}*/
  75 // Connect - Connect to a server                                        /*{{{*/
  76 // ---------------------------------------------------------------------
  77 /* Performs a connection to the server */
  78 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
  79              unsigned long TimeOut,pkgAcqMethod *Owner)
  80 {
  81    if (_error->PendingError() == true)
  82       return false;
  83
  84    /* We used a cached address record.. Yes this is against the spec but
  85       the way we have setup our rotating dns suggests that this is more
  86       sensible */
  87    if (LastHost != Host || LastPort != Port)
  88    {
  89       Owner->Status("Connecting to %s",Host.c_str());
  90
  91       // Lookup the host
  92       char S[300];
  93       if (Port != 0)
  94          snprintf(S,sizeof(S),"%u",Port);
  95       else
  96          snprintf(S,sizeof(S),"%s",Service);
  97
  98       // Free the old address structure
  99       if (LastHostAddr != 0)
 100       {
 101          freeaddrinfo(LastHostAddr);
 102          LastHostAddr = 0;
 103       }
 104
 105       // We only understand SOCK_STREAM sockets.
 106       struct addrinfo Hints;
 107       memset(&Hints,0,sizeof(Hints));
 108       Hints.ai_socktype = SOCK_STREAM;
 109       Hints.ai_protocol = IPPROTO_TCP;       // Right?
 110
 111       // Resolve both the host and service simultaneously
 112       while (1)
 113       {
 114          int Res;
 115          if ((Res = getaddrinfo(Host.c_str(),S,&Hints,&LastHostAddr)) != 0 ||
 116              LastHostAddr == 0)
 117          {
 118             if (Res == EAI_SERVICE)
 119                return _error->Error("Could not resolve service '%s'",S);
 120
 121             if (Res == EAI_NONAME)
 122             {
 123                if (DefPort != 0)
 124                {
 125                   snprintf(S,sizeof(S),"%u",DefPort);
 126                   DefPort = 0;
 127                   continue;
 128                }
 129                return _error->Error("Could not resolve '%s'",Host.c_str());
 130             }
 131
 132             return _error->Error("Something wicked happend resolving '%s/%s'",
 133                                  Host.c_str(),S);
 134          }
 135          break;
 136       }
 137
 138       if (LastHostAddr->ai_family == AF_UNIX)
 139          return _error->Error("getaddrinfo returned a unix domain socket\n");
 140
 141       LastHost = Host;
 142       LastPort = Port;
 143       LastUsed = 0;
 144    }
 145
 146    // Get the printable IP address
 147    struct addrinfo *CurHost = LastHostAddr;
 148    if (LastUsed != 0)
 149        CurHost = LastUsed;
 150
 151    while (CurHost != 0)
 152    {
 153       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 154       {
 155          LastUsed = CurHost;
 156          return true;
 157       }
 158       close(Fd);
 159       Fd = -1;
 160
 161       CurHost = CurHost->ai_next;
 162       LastUsed = 0;
 163       if (CurHost != 0)
 164          _error->Discard();
 165    }
 166
 167    return false;
 168 }
 169                                                                         /*}}}*/