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 <config.h>
  15
  16 #include <apt-pkg/error.h>
  17 #include <apt-pkg/fileutl.h>
  18 #include <apt-pkg/strutl.h>
  19 #include <apt-pkg/acquire-method.h>
  20 #include <apt-pkg/configuration.h>
  21
  22 #include <stdio.h>
  23 #include <errno.h>
  24 #include <unistd.h>
  25 #include <sstream>
  26
  27 #include<set>
  28 #include<string>
  29
  30 // Internet stuff
  31 #include <netinet/in.h>
  32 #include <sys/socket.h>
  33 #include <arpa/inet.h>
  34 #include <netdb.h>
  35
  36 #include "connect.h"
  37 #include "rfc2553emu.h"
  38 #include <apti18n.h>
  39                                                                         /*}}}*/
  40
  41 static std::string LastHost;
  42 static int LastPort = 0;
  43 static struct addrinfo *LastHostAddr = 0;
  44 static struct addrinfo *LastUsed = 0;
  45
  46 // Set of IP/hostnames that we timed out before or couldn't resolve
  47 static std::set<std::string> bad_addr;
  48
  49 // RotateDNS - Select a new server from a DNS rotation                  /*{{{*/
  50 // ---------------------------------------------------------------------
  51 /* This is called during certain errors in order to recover by selecting a
  52    new server */
  53 void RotateDNS()
  54 {
  55    if (LastUsed != 0 && LastUsed->ai_next != 0)
  56       LastUsed = LastUsed->ai_next;
  57    else
  58       LastUsed = LastHostAddr;
  59 }
  60                                                                         /*}}}*/
  61 // DoConnect - Attempt a connect operation                              /*{{{*/
  62 // ---------------------------------------------------------------------
  63 /* This helper function attempts a connection to a single address. */
  64 static bool DoConnect(struct addrinfo *Addr,std::string Host,
  65                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  66 {
  67    // Show a status indicator
  68    char Name[NI_MAXHOST];
  69    char Service[NI_MAXSERV];
  70
  71    Name[0] = 0;
  72    Service[0] = 0;
  73    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  74                Name,sizeof(Name),Service,sizeof(Service),
  75                NI_NUMERICHOST|NI_NUMERICSERV);
  76    Owner->Status(_("Connecting to %s (%s)"),Host.c_str(),Name);
  77
  78    // if that addr did timeout before, we do not try it again
  79    if(bad_addr.find(std::string(Name)) != bad_addr.end())
  80       return false;
  81
  82    /* If this is an IP rotation store the IP we are using.. If something goes
  83       wrong this will get tacked onto the end of the error message */
  84    if (LastHostAddr->ai_next != 0)
  85    {
  86       std::stringstream ss;
  87       ioprintf(ss, _("[IP: %s %s]"),Name,Service);
  88       Owner->SetIP(ss.str());
  89    }
  90
  91    // Get a socket
  92    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  93                     Addr->ai_protocol)) < 0)
  94       return _error->Errno("socket",_("Could not create a socket for %s (f=%u t=%u p=%u)"),
  95                            Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol);
  96
  97    SetNonBlock(Fd,true);
  98    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  99        errno != EINPROGRESS)
 100       return _error->Errno("connect",_("Cannot initiate the connection "
 101                            "to %s:%s (%s)."),Host.c_str(),Service,Name);
 102
 103    /* This implements a timeout for connect by opening the connection
 104       nonblocking */
 105    if (WaitFd(Fd,true,TimeOut) == false) {
 106       bad_addr.insert(bad_addr.begin(), std::string(Name));
 107       Owner->SetFailReason("Timeout");
 108       return _error->Error(_("Could not connect to %s:%s (%s), "
 109                            "connection timed out"),Host.c_str(),Service,Name);
 110    }
 111
 112    // Check the socket for an error condition
 113    unsigned int Err;
 114    unsigned int Len = sizeof(Err);
 115    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
 116       return _error->Errno("getsockopt",_("Failed"));
 117
 118    if (Err != 0)
 119    {
 120       errno = Err;
 121       if(errno == ECONNREFUSED)
 122          Owner->SetFailReason("ConnectionRefused");
 123       else if (errno == ETIMEDOUT)
 124          Owner->SetFailReason("ConnectionTimedOut");
 125       bad_addr.insert(bad_addr.begin(), std::string(Name));
 126       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 127                            Service,Name);
 128    }
 129
 130    return true;
 131 }
 132                                                                         /*}}}*/
 133 // Connect - Connect to a server                                        /*{{{*/
 134 // ---------------------------------------------------------------------
 135 /* Performs a connection to the server */
 136 bool Connect(std::string Host,int Port,const char *Service,int DefPort,int &Fd,
 137              unsigned long TimeOut,pkgAcqMethod *Owner)
 138 {
 139    if (_error->PendingError() == true)
 140       return false;
 141
 142    // Convert the port name/number
 143    char ServStr[300];
 144    if (Port != 0)
 145       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 146    else
 147       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 148
 149    /* We used a cached address record.. Yes this is against the spec but
 150       the way we have setup our rotating dns suggests that this is more
 151       sensible */
 152    if (LastHost != Host || LastPort != Port)
 153    {
 154       Owner->Status(_("Connecting to %s"),Host.c_str());
 155
 156       // Free the old address structure
 157       if (LastHostAddr != 0)
 158       {
 159          freeaddrinfo(LastHostAddr);
 160          LastHostAddr = 0;
 161          LastUsed = 0;
 162       }
 163
 164       // We only understand SOCK_STREAM sockets.
 165       struct addrinfo Hints;
 166       memset(&Hints,0,sizeof(Hints));
 167       Hints.ai_socktype = SOCK_STREAM;
 168       Hints.ai_flags = AI_ADDRCONFIG;
 169       Hints.ai_protocol = 0;
 170
 171       if(_config->FindB("Acquire::ForceIPv4", false) == true)
 172          Hints.ai_family = AF_INET;
 173       else if(_config->FindB("Acquire::ForceIPv6", false) == true)
 174          Hints.ai_family = AF_INET6;
 175       else
 176          Hints.ai_family = AF_UNSPEC;
 177
 178       // if we couldn't resolve the host before, we don't try now
 179       if(bad_addr.find(Host) != bad_addr.end())
 180          return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 181
 182       // Resolve both the host and service simultaneously
 183       while (1)
 184       {
 185          int Res;
 186          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 187              LastHostAddr == 0)
 188          {
 189             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 190             {
 191                if (DefPort != 0)
 192                {
 193                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 194                   DefPort = 0;
 195                   continue;
 196                }
 197                bad_addr.insert(bad_addr.begin(), Host);
 198                Owner->SetFailReason("ResolveFailure");
 199                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 200             }
 201
 202             if (Res == EAI_AGAIN)
 203             {
 204                Owner->SetFailReason("TmpResolveFailure");
 205                return _error->Error(_("Temporary failure resolving '%s'"),
 206                                     Host.c_str());
 207             }
 208             if (Res == EAI_SYSTEM)
 209                return _error->Errno("getaddrinfo", _("System error resolving '%s:%s'"),
 210                                       Host.c_str(),ServStr);
 211             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i - %s)"),
 212                                  Host.c_str(),ServStr,Res,gai_strerror(Res));
 213          }
 214          break;
 215       }
 216
 217       LastHost = Host;
 218       LastPort = Port;
 219    }
 220
 221    // When we have an IP rotation stay with the last IP.
 222    struct addrinfo *CurHost = LastHostAddr;
 223    if (LastUsed != 0)
 224        CurHost = LastUsed;
 225
 226    while (CurHost != 0)
 227    {
 228       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 229       {
 230          LastUsed = CurHost;
 231          return true;
 232       }
 233       close(Fd);
 234       Fd = -1;
 235
 236       // Ignore UNIX domain sockets
 237       do
 238       {
 239          CurHost = CurHost->ai_next;
 240       }
 241       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 242
 243       /* If we reached the end of the search list then wrap around to the
 244          start */
 245       if (CurHost == 0 && LastUsed != 0)
 246          CurHost = LastHostAddr;
 247
 248       // Reached the end of the search cycle
 249       if (CurHost == LastUsed)
 250          break;
 251
 252       if (CurHost != 0)
 253          _error->Discard();
 254    }
 255
 256    if (_error->PendingError() == true)
 257       return false;
 258    return _error->Error(_("Unable to connect to %s:%s:"),Host.c_str(),ServStr);
 259 }
 260                                                                         /*}}}*/