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