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
  22 // Internet stuff
  23 #include <netinet/in.h>
  24 #include <sys/socket.h>
  25 #include <arpa/inet.h>
  26 #include <netdb.h>
  27
  28 #include "rfc2553emu.h"
  29 #include <apti18n.h>
  30                                                                         /*}}}*/
  31
  32 static string LastHost;
  33 static int LastPort = 0;
  34 static struct addrinfo *LastHostAddr = 0;
  35 static struct addrinfo *LastUsed = 0;
  36
  37 // RotateDNS - Select a new server from a DNS rotation                  /*{{{*/
  38 // ---------------------------------------------------------------------
  39 /* This is called during certain errors in order to recover by selecting a
  40    new server */
  41 void RotateDNS()
  42 {
  43    if (LastUsed != 0 && LastUsed->ai_next != 0)
  44       LastUsed = LastUsed->ai_next;
  45    else
  46       LastUsed = LastHostAddr;
  47 }
  48                                                                         /*}}}*/
  49 // DoConnect - Attempt a connect operation                              /*{{{*/
  50 // ---------------------------------------------------------------------
  51 /* This helper function attempts a connection to a single address. */
  52 static bool DoConnect(struct addrinfo *Addr,string Host,
  53                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  54 {
  55    // Show a status indicator
  56    char Name[NI_MAXHOST];
  57    char Service[NI_MAXSERV];
  58
  59    Name[0] = 0;
  60    Service[0] = 0;
  61    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  62                Name,sizeof(Name),Service,sizeof(Service),
  63                NI_NUMERICHOST|NI_NUMERICSERV);
  64    Owner->Status(_("Connecting to %s (%s)"),Host.c_str(),Name);
  65
  66    /* If this is an IP rotation store the IP we are using.. If something goes
  67       wrong this will get tacked onto the end of the error message */
  68    if (LastHostAddr->ai_next != 0)
  69    {
  70       char Name2[NI_MAXHOST + NI_MAXSERV + 10];
  71       snprintf(Name2,sizeof(Name2),_("[IP: %s %s]"),Name,Service);
  72       Owner->SetFailExtraMsg(string(Name2));
  73    }
  74    else
  75       Owner->SetFailExtraMsg("");
  76
  77    // Get a socket
  78    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  79                     Addr->ai_protocol)) < 0)
  80       return _error->Errno("socket",_("Could not create a socket for %s (f=%u t=%u p=%u)"),
  81                            Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol);
  82
  83    SetNonBlock(Fd,true);
  84    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  85        errno != EINPROGRESS)
  86       return _error->Errno("connect",_("Cannot initiate the connection "
  87                            "to %s:%s (%s)."),Host.c_str(),Service,Name);
  88
  89    /* This implements a timeout for connect by opening the connection
  90       nonblocking */
  91    if (WaitFd(Fd,true,TimeOut) == false)
  92       return _error->Error(_("Could not connect to %s:%s (%s), "
  93                            "connection timed out"),Host.c_str(),Service,Name);
  94
  95    // Check the socket for an error condition
  96    unsigned int Err;
  97    unsigned int Len = sizeof(Err);
  98    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
  99       return _error->Errno("getsockopt",_("Failed"));
 100
 101    if (Err != 0)
 102    {
 103       errno = Err;
 104       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 105                            Service,Name);
 106    }
 107
 108    return true;
 109 }
 110                                                                         /*}}}*/
 111 // Connect - Connect to a server                                        /*{{{*/
 112 // ---------------------------------------------------------------------
 113 /* Performs a connection to the server */
 114 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
 115              unsigned long TimeOut,pkgAcqMethod *Owner)
 116 {
 117    if (_error->PendingError() == true)
 118       return false;
 119
 120    // Convert the port name/number
 121    char ServStr[300];
 122    if (Port != 0)
 123       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 124    else
 125       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 126
 127    /* We used a cached address record.. Yes this is against the spec but
 128       the way we have setup our rotating dns suggests that this is more
 129       sensible */
 130    if (LastHost != Host || LastPort != Port)
 131    {
 132       Owner->Status(_("Connecting to %s"),Host.c_str());
 133
 134       // Free the old address structure
 135       if (LastHostAddr != 0)
 136       {
 137          freeaddrinfo(LastHostAddr);
 138          LastHostAddr = 0;
 139          LastUsed = 0;
 140       }
 141
 142       // We only understand SOCK_STREAM sockets.
 143       struct addrinfo Hints;
 144       memset(&Hints,0,sizeof(Hints));
 145       Hints.ai_socktype = SOCK_STREAM;
 146       Hints.ai_protocol = 0;
 147
 148       // Resolve both the host and service simultaneously
 149       while (1)
 150       {
 151          int Res;
 152          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 153              LastHostAddr == 0)
 154          {
 155             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 156             {
 157                if (DefPort != 0)
 158                {
 159                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 160                   DefPort = 0;
 161                   continue;
 162                }
 163                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 164             }
 165
 166             if (Res == EAI_AGAIN)
 167                return _error->Error(_("Temporary failure resolving '%s'"),
 168                                     Host.c_str());
 169             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i)"),
 170                                  Host.c_str(),ServStr,Res);
 171          }
 172          break;
 173       }
 174
 175       LastHost = Host;
 176       LastPort = Port;
 177    }
 178
 179    // When we have an IP rotation stay with the last IP.
 180    struct addrinfo *CurHost = LastHostAddr;
 181    if (LastUsed != 0)
 182        CurHost = LastUsed;
 183
 184    while (CurHost != 0)
 185    {
 186       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 187       {
 188          LastUsed = CurHost;
 189          return true;
 190       }
 191       close(Fd);
 192       Fd = -1;
 193
 194       // Ignore UNIX domain sockets
 195       do
 196       {
 197          CurHost = CurHost->ai_next;
 198       }
 199       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 200
 201       /* If we reached the end of the search list then wrap around to the
 202          start */
 203       if (CurHost == 0 && LastUsed != 0)
 204          CurHost = LastHostAddr;
 205
 206       // Reached the end of the search cycle
 207       if (CurHost == LastUsed)
 208          break;
 209
 210       if (CurHost != 0)
 211          _error->Discard();
 212    }
 213
 214    if (_error->PendingError() == true)
 215       return false;
 216    return _error->Error(_("Unable to connect to %s %s:"),Host.c_str(),ServStr);
 217 }
 218                                                                         /*}}}*/