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