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       Owner->SetFailExtraMsg("\nFailReason: Timeout");
  93       return _error->Error(_("Could not connect to %s:%s (%s), "
  94                            "connection timed out"),Host.c_str(),Service,Name);
  95    }
  96
  97    // Check the socket for an error condition
  98    unsigned int Err;
  99    unsigned int Len = sizeof(Err);
 100    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
 101       return _error->Errno("getsockopt",_("Failed"));
 102
 103    if (Err != 0)
 104    {
 105       errno = Err;
 106       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 107                            Service,Name);
 108    }
 109
 110    return true;
 111 }
 112                                                                         /*}}}*/
 113 // Connect - Connect to a server                                        /*{{{*/
 114 // ---------------------------------------------------------------------
 115 /* Performs a connection to the server */
 116 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
 117              unsigned long TimeOut,pkgAcqMethod *Owner)
 118 {
 119    if (_error->PendingError() == true)
 120       return false;
 121
 122    // Convert the port name/number
 123    char ServStr[300];
 124    if (Port != 0)
 125       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 126    else
 127       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 128
 129    /* We used a cached address record.. Yes this is against the spec but
 130       the way we have setup our rotating dns suggests that this is more
 131       sensible */
 132    if (LastHost != Host || LastPort != Port)
 133    {
 134       Owner->Status(_("Connecting to %s"),Host.c_str());
 135
 136       // Free the old address structure
 137       if (LastHostAddr != 0)
 138       {
 139          freeaddrinfo(LastHostAddr);
 140          LastHostAddr = 0;
 141          LastUsed = 0;
 142       }
 143
 144       // We only understand SOCK_STREAM sockets.
 145       struct addrinfo Hints;
 146       memset(&Hints,0,sizeof(Hints));
 147       Hints.ai_socktype = SOCK_STREAM;
 148       Hints.ai_protocol = 0;
 149
 150       // Resolve both the host and service simultaneously
 151       while (1)
 152       {
 153          int Res;
 154          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 155              LastHostAddr == 0)
 156          {
 157             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 158             {
 159                if (DefPort != 0)
 160                {
 161                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 162                   DefPort = 0;
 163                   continue;
 164                }
 165                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 166             }
 167
 168             if (Res == EAI_AGAIN)
 169                return _error->Error(_("Temporary failure resolving '%s'"),
 170                                     Host.c_str());
 171             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i)"),
 172                                  Host.c_str(),ServStr,Res);
 173          }
 174          break;
 175       }
 176
 177       LastHost = Host;
 178       LastPort = Port;
 179    }
 180
 181    // When we have an IP rotation stay with the last IP.
 182    struct addrinfo *CurHost = LastHostAddr;
 183    if (LastUsed != 0)
 184        CurHost = LastUsed;
 185
 186    while (CurHost != 0)
 187    {
 188       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 189       {
 190          LastUsed = CurHost;
 191          return true;
 192       }
 193       close(Fd);
 194       Fd = -1;
 195
 196       // Ignore UNIX domain sockets
 197       do
 198       {
 199          CurHost = CurHost->ai_next;
 200       }
 201       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 202
 203       /* If we reached the end of the search list then wrap around to the
 204          start */
 205       if (CurHost == 0 && LastUsed != 0)
 206          CurHost = LastHostAddr;
 207
 208       // Reached the end of the search cycle
 209       if (CurHost == LastUsed)
 210          break;
 211
 212       if (CurHost != 0)
 213          _error->Discard();
 214    }
 215
 216    if (_error->PendingError() == true)
 217       return false;
 218    return _error->Error(_("Unable to connect to %s %s:"),Host.c_str(),ServStr);
 219 }
 220                                                                         /*}}}*/