methods/connect.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: connect.cc,v 1.6 2000/05/28 04:34:44 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    char Service[NI_MAXSERV];
  42    Name[0] = 0;
  43    Service[0] = 0;
  44    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  45                Name,sizeof(Name),Service,sizeof(Service),
  46                NI_NUMERICHOST|NI_NUMERICSERV);
  47    Owner->Status("Connecting to %s (%s)",Host.c_str(),Name);
  48
  49    // Get a socket
  50    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  51                     Addr->ai_protocol)) < 0)
  52       return _error->Errno("socket","Could not create a socket");
  53
  54    SetNonBlock(Fd,true);
  55    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  56        errno != EINPROGRESS)
  57       return _error->Errno("connect","Cannot initiate the connection "
  58                            "to %s:%s (%s).",Host.c_str(),Service,Name);
  59
  60    /* This implements a timeout for connect by opening the connection
  61       nonblocking */
  62    if (WaitFd(Fd,true,TimeOut) == false)
  63       return _error->Error("Could not connect to %s:%s (%s), "
  64                            "connection timed out",Host.c_str(),Service,Name);
  65
  66    // Check the socket for an error condition
  67    unsigned int Err;
  68    unsigned int Len = sizeof(Err);
  69    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
  70       return _error->Errno("getsockopt","Failed");
  71
  72    if (Err != 0)
  73    {
  74       errno = Err;
  75       return _error->Errno("connect","Could not connect to %s:%s (%s).",Host.c_str(),
  76                            Service,Name);
  77    }
  78
  79    return true;
  80 }
  81                                                                         /*}}}*/
  82 // Connect - Connect to a server                                        /*{{{*/
  83 // ---------------------------------------------------------------------
  84 /* Performs a connection to the server */
  85 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
  86              unsigned long TimeOut,pkgAcqMethod *Owner)
  87 {
  88    if (_error->PendingError() == true)
  89       return false;
  90
  91    // Convert the port name/number
  92    char ServStr[300];
  93    if (Port != 0)
  94       snprintf(ServStr,sizeof(ServStr),"%u",Port);
  95    else
  96       snprintf(ServStr,sizeof(ServStr),"%s",Service);
  97
  98    /* We used a cached address record.. Yes this is against the spec but
  99       the way we have setup our rotating dns suggests that this is more
 100       sensible */
 101    if (LastHost != Host || LastPort != Port)
 102    {
 103       Owner->Status("Connecting to %s",Host.c_str());
 104
 105       // Free the old address structure
 106       if (LastHostAddr != 0)
 107       {
 108          freeaddrinfo(LastHostAddr);
 109          LastHostAddr = 0;
 110          LastUsed = 0;
 111       }
 112
 113       // We only understand SOCK_STREAM sockets.
 114       struct addrinfo Hints;
 115       memset(&Hints,0,sizeof(Hints));
 116       Hints.ai_socktype = SOCK_STREAM;
 117       Hints.ai_protocol = 0;
 118
 119       // Resolve both the host and service simultaneously
 120       while (1)
 121       {
 122          int Res;
 123          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 124              LastHostAddr == 0)
 125          {
 126             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 127             {
 128                if (DefPort != 0)
 129                {
 130                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 131                   DefPort = 0;
 132                   continue;
 133                }
 134                return _error->Error("Could not resolve '%s'",Host.c_str());
 135             }
 136
 137             return _error->Error("Something wicked happend resolving '%s:%s'",
 138                                  Host.c_str(),ServStr);
 139          }
 140          break;
 141       }
 142
 143       LastHost = Host;
 144       LastPort = Port;
 145    }
 146
 147    // When we have an IP rotation stay with the last IP.
 148    struct addrinfo *CurHost = LastHostAddr;
 149    if (LastUsed != 0)
 150        CurHost = LastUsed;
 151
 152    while (CurHost != 0)
 153    {
 154       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 155       {
 156          LastUsed = CurHost;
 157          return true;
 158       }
 159       close(Fd);
 160       Fd = -1;
 161
 162       // Ignore UNIX domain sockets
 163       do
 164       {
 165          CurHost = CurHost->ai_next;
 166       }
 167       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 168
 169       LastUsed = 0;
 170       if (CurHost != 0)
 171          _error->Discard();
 172    }
 173
 174    if (_error->PendingError() == true)
 175       return false;
 176    return _error->Error("Unable to connect to %s:",Host.c_str(),ServStr);
 177 }
 178                                                                         /*}}}*/