methods/connect.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: connect.cc,v 1.10.2.1 2004/01/16 18:58:50 mdz Exp $
   4 /* ######################################################################
   5
   6    Connect - Replacement connect call
   7
   8    This was originally authored by Jason Gunthorpe <jgg@debian.org>
   9    and is placed in the Public Domain, do with it what you will.
  10
  11    ##################################################################### */
  12                                                                         /*}}}*/
  13 // Include Files                                                        /*{{{*/
  14 #include "connect.h"
  15 #include <apt-pkg/error.h>
  16 #include <apt-pkg/fileutl.h>
  17
  18 #include <stdio.h>
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <sstream>
  22
  23 // Internet stuff
  24 #include <netinet/in.h>
  25 #include <sys/socket.h>
  26 #include <arpa/inet.h>
  27 #include <netdb.h>
  28
  29 #include "rfc2553emu.h"
  30 #include <apti18n.h>
  31                                                                         /*}}}*/
  32
  33 static string LastHost;
  34 static int LastPort = 0;
  35 static struct addrinfo *LastHostAddr = 0;
  36 static struct addrinfo *LastUsed = 0;
  37
  38 // RotateDNS - Select a new server from a DNS rotation                  /*{{{*/
  39 // ---------------------------------------------------------------------
  40 /* This is called during certain errors in order to recover by selecting a
  41    new server */
  42 void RotateDNS()
  43 {
  44    if (LastUsed != 0 && LastUsed->ai_next != 0)
  45       LastUsed = LastUsed->ai_next;
  46    else
  47       LastUsed = LastHostAddr;
  48 }
  49                                                                         /*}}}*/
  50 // DoConnect - Attempt a connect operation                              /*{{{*/
  51 // ---------------------------------------------------------------------
  52 /* This helper function attempts a connection to a single address. */
  53 static bool DoConnect(struct addrinfo *Addr,string Host,
  54                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  55 {
  56    // Show a status indicator
  57    char Name[NI_MAXHOST];
  58    char Service[NI_MAXSERV];
  59
  60    Name[0] = 0;
  61    Service[0] = 0;
  62    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  63                Name,sizeof(Name),Service,sizeof(Service),
  64                NI_NUMERICHOST|NI_NUMERICSERV);
  65    Owner->Status(_("Connecting to %s (%s)"),Host.c_str(),Name);
  66
  67    /* If this is an IP rotation store the IP we are using.. If something goes
  68       wrong this will get tacked onto the end of the error message */
  69    if (LastHostAddr->ai_next != 0)
  70    {
  71       std::stringstream ss;
  72       ioprintf(ss, _("[IP: %s %s]"),Name,Service);
  73       Owner->SetIP(ss.str());
  74    }
  75
  76    // Get a socket
  77    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  78                     Addr->ai_protocol)) < 0)
  79       return _error->Errno("socket",_("Could not create a socket for %s (f=%u t=%u p=%u)"),
  80                            Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol);
  81
  82    SetNonBlock(Fd,true);
  83    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  84        errno != EINPROGRESS)
  85       return _error->Errno("connect",_("Cannot initiate the connection "
  86                            "to %s:%s (%s)."),Host.c_str(),Service,Name);
  87
  88    /* This implements a timeout for connect by opening the connection
  89       nonblocking */
  90    if (WaitFd(Fd,true,TimeOut) == false) {
  91       Owner->SetFailReason("Timeout");
  92       return _error->Error(_("Could not connect to %s:%s (%s), "
  93                            "connection timed out"),Host.c_str(),Service,Name);
  94    }
  95
  96    // Check the socket for an error condition
  97    unsigned int Err;
  98    unsigned int Len = sizeof(Err);
  99    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
 100       return _error->Errno("getsockopt",_("Failed"));
 101
 102    if (Err != 0)
 103    {
 104       errno = Err;
 105       if(errno == ECONNREFUSED)
 106          Owner->SetFailReason("ConnectionRefused");
 107       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 108                            Service,Name);
 109    }
 110
 111    return true;
 112 }
 113                                                                         /*}}}*/
 114 // Connect - Connect to a server                                        /*{{{*/
 115 // ---------------------------------------------------------------------
 116 /* Performs a connection to the server */
 117 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
 118              unsigned long TimeOut,pkgAcqMethod *Owner)
 119 {
 120    if (_error->PendingError() == true)
 121       return false;
 122
 123    // Convert the port name/number
 124    char ServStr[300];
 125    if (Port != 0)
 126       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 127    else
 128       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 129
 130    /* We used a cached address record.. Yes this is against the spec but
 131       the way we have setup our rotating dns suggests that this is more
 132       sensible */
 133    if (LastHost != Host || LastPort != Port)
 134    {
 135       Owner->Status(_("Connecting to %s"),Host.c_str());
 136
 137       // Free the old address structure
 138       if (LastHostAddr != 0)
 139       {
 140          freeaddrinfo(LastHostAddr);
 141          LastHostAddr = 0;
 142          LastUsed = 0;
 143       }
 144
 145       // We only understand SOCK_STREAM sockets.
 146       struct addrinfo Hints;
 147       memset(&Hints,0,sizeof(Hints));
 148       Hints.ai_socktype = SOCK_STREAM;
 149       Hints.ai_protocol = 0;
 150
 151       // Resolve both the host and service simultaneously
 152       while (1)
 153       {
 154          int Res;
 155          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 156              LastHostAddr == 0)
 157          {
 158             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 159             {
 160                if (DefPort != 0)
 161                {
 162                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 163                   DefPort = 0;
 164                   continue;
 165                }
 166                Owner->SetFailReason("ResolveFailure");
 167                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 168             }
 169
 170             if (Res == EAI_AGAIN)
 171             {
 172                Owner->SetFailReason("TmpResolveFailure");
 173                return _error->Error(_("Temporary failure resolving '%s'"),
 174                                     Host.c_str());
 175             }
 176             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i)"),
 177                                  Host.c_str(),ServStr,Res);
 178          }
 179          break;
 180       }
 181
 182       LastHost = Host;
 183       LastPort = Port;
 184    }
 185
 186    // When we have an IP rotation stay with the last IP.
 187    struct addrinfo *CurHost = LastHostAddr;
 188    if (LastUsed != 0)
 189        CurHost = LastUsed;
 190
 191    while (CurHost != 0)
 192    {
 193       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 194       {
 195          LastUsed = CurHost;
 196          return true;
 197       }
 198       close(Fd);
 199       Fd = -1;
 200
 201       // Ignore UNIX domain sockets
 202       do
 203       {
 204          CurHost = CurHost->ai_next;
 205       }
 206       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 207
 208       /* If we reached the end of the search list then wrap around to the
 209          start */
 210       if (CurHost == 0 && LastUsed != 0)
 211          CurHost = LastHostAddr;
 212
 213       // Reached the end of the search cycle
 214       if (CurHost == LastUsed)
 215          break;
 216
 217       if (CurHost != 0)
 218          _error->Discard();
 219    }
 220
 221    if (_error->PendingError() == true)
 222       return false;
 223    return _error->Error(_("Unable to connect to %s %s:"),Host.c_str(),ServStr);
 224 }
 225                                                                         /*}}}*/