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 #include<set>
  23 #include<string>
  24
  25 // Internet stuff
  26 #include <netinet/in.h>
  27 #include <sys/socket.h>
  28 #include <arpa/inet.h>
  29 #include <netdb.h>
  30
  31 #include "rfc2553emu.h"
  32 #include <apti18n.h>
  33                                                                         /*}}}*/
  34
  35 static string LastHost;
  36 static int LastPort = 0;
  37 static struct addrinfo *LastHostAddr = 0;
  38 static struct addrinfo *LastUsed = 0;
  39
  40 // Set of IP/hostnames that we timed out before or couldn't resolve
  41 static std::set<string> bad_addr;
  42
  43 // RotateDNS - Select a new server from a DNS rotation                  /*{{{*/
  44 // ---------------------------------------------------------------------
  45 /* This is called during certain errors in order to recover by selecting a
  46    new server */
  47 void RotateDNS()
  48 {
  49    if (LastUsed != 0 && LastUsed->ai_next != 0)
  50       LastUsed = LastUsed->ai_next;
  51    else
  52       LastUsed = LastHostAddr;
  53 }
  54                                                                         /*}}}*/
  55 // DoConnect - Attempt a connect operation                              /*{{{*/
  56 // ---------------------------------------------------------------------
  57 /* This helper function attempts a connection to a single address. */
  58 static bool DoConnect(struct addrinfo *Addr,string Host,
  59                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  60 {
  61    // Show a status indicator
  62    char Name[NI_MAXHOST];
  63    char Service[NI_MAXSERV];
  64
  65    Name[0] = 0;
  66    Service[0] = 0;
  67    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  68                Name,sizeof(Name),Service,sizeof(Service),
  69                NI_NUMERICHOST|NI_NUMERICSERV);
  70    Owner->Status(_("Connecting to %s (%s)"),Host.c_str(),Name);
  71
  72    // if that addr did timeout before, we do not try it again
  73    if(bad_addr.find(string(Name)) != bad_addr.end())
  74       return false;
  75
  76    /* If this is an IP rotation store the IP we are using.. If something goes
  77       wrong this will get tacked onto the end of the error message */
  78    if (LastHostAddr->ai_next != 0)
  79    {
  80       char Name2[NI_MAXHOST + NI_MAXSERV + 10];
  81       snprintf(Name2,sizeof(Name2),_("[IP: %s %s]"),Name,Service);
  82       Owner->SetFailExtraMsg(string(Name2));
  83    }
  84    else
  85       Owner->SetFailExtraMsg("");
  86
  87    // Get a socket
  88    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  89                     Addr->ai_protocol)) < 0)
  90       return _error->Errno("socket",_("Could not create a socket for %s (f=%u t=%u p=%u)"),
  91                            Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol);
  92
  93    SetNonBlock(Fd,true);
  94    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  95        errno != EINPROGRESS)
  96       return _error->Errno("connect",_("Cannot initiate the connection "
  97                            "to %s:%s (%s)."),Host.c_str(),Service,Name);
  98
  99    /* This implements a timeout for connect by opening the connection
 100       nonblocking */
 101    if (WaitFd(Fd,true,TimeOut) == false) {
 102       bad_addr.insert(bad_addr.begin(), string(Name));
 103       Owner->SetFailExtraMsg("\nFailReason: Timeout");
 104       return _error->Error(_("Could not connect to %s:%s (%s), "
 105                            "connection timed out"),Host.c_str(),Service,Name);
 106    }
 107
 108    // Check the socket for an error condition
 109    unsigned int Err;
 110    unsigned int Len = sizeof(Err);
 111    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
 112       return _error->Errno("getsockopt",_("Failed"));
 113
 114    if (Err != 0)
 115    {
 116       errno = Err;
 117       if(errno == ECONNREFUSED)
 118          Owner->SetFailExtraMsg("\nFailReason: ConnectionRefused");
 119       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 120                            Service,Name);
 121    }
 122
 123    return true;
 124 }
 125                                                                         /*}}}*/
 126 // Connect - Connect to a server                                        /*{{{*/
 127 // ---------------------------------------------------------------------
 128 /* Performs a connection to the server */
 129 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
 130              unsigned long TimeOut,pkgAcqMethod *Owner)
 131 {
 132    if (_error->PendingError() == true)
 133       return false;
 134
 135    // Convert the port name/number
 136    char ServStr[300];
 137    if (Port != 0)
 138       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 139    else
 140       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 141
 142    /* We used a cached address record.. Yes this is against the spec but
 143       the way we have setup our rotating dns suggests that this is more
 144       sensible */
 145    if (LastHost != Host || LastPort != Port)
 146    {
 147       Owner->Status(_("Connecting to %s"),Host.c_str());
 148
 149       // Free the old address structure
 150       if (LastHostAddr != 0)
 151       {
 152          freeaddrinfo(LastHostAddr);
 153          LastHostAddr = 0;
 154          LastUsed = 0;
 155       }
 156
 157       // We only understand SOCK_STREAM sockets.
 158       struct addrinfo Hints;
 159       memset(&Hints,0,sizeof(Hints));
 160       Hints.ai_socktype = SOCK_STREAM;
 161       Hints.ai_flags = AI_ADDRCONFIG;
 162       Hints.ai_protocol = 0;
 163
 164       // if we couldn't resolve the host before, we don't try now
 165       if(bad_addr.find(Host) != bad_addr.end())
 166          return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 167
 168       // Resolve both the host and service simultaneously
 169       while (1)
 170       {
 171          int Res;
 172          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 173              LastHostAddr == 0)
 174          {
 175             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 176             {
 177                if (DefPort != 0)
 178                {
 179                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 180                   DefPort = 0;
 181                   continue;
 182                }
 183                bad_addr.insert(bad_addr.begin(), Host);
 184                Owner->SetFailExtraMsg("\nFailReason: ResolveFailure");
 185                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 186             }
 187
 188             if (Res == EAI_AGAIN)
 189             {
 190                Owner->SetFailExtraMsg("\nFailReason: TmpResolveFailure");
 191                return _error->Error(_("Temporary failure resolving '%s'"),
 192                                     Host.c_str());
 193             }
 194             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i - %s)"),
 195                                  Host.c_str(),ServStr,Res,gai_strerror(Res));
 196          }
 197          break;
 198       }
 199
 200       LastHost = Host;
 201       LastPort = Port;
 202    }
 203
 204    // When we have an IP rotation stay with the last IP.
 205    struct addrinfo *CurHost = LastHostAddr;
 206    if (LastUsed != 0)
 207        CurHost = LastUsed;
 208
 209    while (CurHost != 0)
 210    {
 211       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 212       {
 213          LastUsed = CurHost;
 214          return true;
 215       }
 216       close(Fd);
 217       Fd = -1;
 218
 219       // Ignore UNIX domain sockets
 220       do
 221       {
 222          CurHost = CurHost->ai_next;
 223       }
 224       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 225
 226       /* If we reached the end of the search list then wrap around to the
 227          start */
 228       if (CurHost == 0 && LastUsed != 0)
 229          CurHost = LastHostAddr;
 230
 231       // Reached the end of the search cycle
 232       if (CurHost == LastUsed)
 233          break;
 234
 235       if (CurHost != 0)
 236          _error->Discard();
 237    }
 238
 239    if (_error->PendingError() == true)
 240       return false;
 241    return _error->Error(_("Unable to connect to %s:%s:"),Host.c_str(),ServStr);
 242 }
 243                                                                         /*}}}*/