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