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 #include <apt-pkg/srvrec.h>
  22
  23 #include <stdio.h>
  24 #include <errno.h>
  25 #include <unistd.h>
  26 #include <sstream>
  27 #include <string.h>
  28 #include<set>
  29 #include<string>
  30
  31 // Internet stuff
  32 #include <netinet/in.h>
  33 #include <sys/socket.h>
  34 #include <arpa/inet.h>
  35 #include <netdb.h>
  36
  37 #include "connect.h"
  38 #include "rfc2553emu.h"
  39 #include <apti18n.h>
  40                                                                         /*}}}*/
  41
  42 static std::string LastHost;
  43 static int LastPort = 0;
  44 static struct addrinfo *LastHostAddr = 0;
  45 static struct addrinfo *LastUsed = 0;
  46
  47 static std::vector<SrvRec> SrvRecords;
  48 static int LastSrvRecord = 0;
  49
  50 // Set of IP/hostnames that we timed out before or couldn't resolve
  51 static std::set<std::string> bad_addr;
  52
  53 // RotateDNS - Select a new server from a DNS rotation                  /*{{{*/
  54 // ---------------------------------------------------------------------
  55 /* This is called during certain errors in order to recover by selecting a
  56    new server */
  57 void RotateDNS()
  58 {
  59    if (LastUsed != 0 && LastUsed->ai_next != 0)
  60       LastUsed = LastUsed->ai_next;
  61    else
  62       LastUsed = LastHostAddr;
  63 }
  64                                                                         /*}}}*/
  65 // DoConnect - Attempt a connect operation                              /*{{{*/
  66 // ---------------------------------------------------------------------
  67 /* This helper function attempts a connection to a single address. */
  68 static bool DoConnect(struct addrinfo *Addr,std::string Host,
  69                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  70 {
  71    // Show a status indicator
  72    char Name[NI_MAXHOST];
  73    char Service[NI_MAXSERV];
  74
  75    Name[0] = 0;
  76    Service[0] = 0;
  77    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  78                Name,sizeof(Name),Service,sizeof(Service),
  79                NI_NUMERICHOST|NI_NUMERICSERV);
  80    Owner->Status(_("Connecting to %s (%s)"),Host.c_str(),Name);
  81
  82    // if that addr did timeout before, we do not try it again
  83    if(bad_addr.find(std::string(Name)) != bad_addr.end())
  84       return false;
  85
  86    /* If this is an IP rotation store the IP we are using.. If something goes
  87       wrong this will get tacked onto the end of the error message */
  88    if (LastHostAddr->ai_next != 0)
  89    {
  90       std::stringstream ss;
  91       ioprintf(ss, _("[IP: %s %s]"),Name,Service);
  92       Owner->SetIP(ss.str());
  93    }
  94
  95    // Get a socket
  96    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  97                     Addr->ai_protocol)) < 0)
  98       return _error->Errno("socket",_("Could not create a socket for %s (f=%u t=%u p=%u)"),
  99                            Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol);
 100
 101    SetNonBlock(Fd,true);
 102    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
 103        errno != EINPROGRESS)
 104       return _error->Errno("connect",_("Cannot initiate the connection "
 105                            "to %s:%s (%s)."),Host.c_str(),Service,Name);
 106
 107    /* This implements a timeout for connect by opening the connection
 108       nonblocking */
 109    if (WaitFd(Fd,true,TimeOut) == false) {
 110       bad_addr.insert(bad_addr.begin(), std::string(Name));
 111       Owner->SetFailReason("Timeout");
 112       return _error->Error(_("Could not connect to %s:%s (%s), "
 113                            "connection timed out"),Host.c_str(),Service,Name);
 114    }
 115
 116    // Check the socket for an error condition
 117    unsigned int Err;
 118    unsigned int Len = sizeof(Err);
 119    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
 120       return _error->Errno("getsockopt",_("Failed"));
 121
 122    if (Err != 0)
 123    {
 124       errno = Err;
 125       if(errno == ECONNREFUSED)
 126          Owner->SetFailReason("ConnectionRefused");
 127       else if (errno == ETIMEDOUT)
 128          Owner->SetFailReason("ConnectionTimedOut");
 129       bad_addr.insert(bad_addr.begin(), std::string(Name));
 130       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 131                            Service,Name);
 132    }
 133
 134    return true;
 135 }
 136                                                                         /*}}}*/
 137
 138 // Connect to a given Hostname
 139 bool ConnectToHostname(std::string Host,int Port,const char *Service,
 140                             int DefPort,int &Fd,
 141                             unsigned long TimeOut,pkgAcqMethod *Owner)
 142 {
 143    // Convert the port name/number
 144    char ServStr[300];
 145    if (Port != 0)
 146       snprintf(ServStr,sizeof(ServStr),"%i", Port);
 147    else
 148       snprintf(ServStr,sizeof(ServStr),"%s", Service);
 149
 150    /* We used a cached address record.. Yes this is against the spec but
 151       the way we have setup our rotating dns suggests that this is more
 152       sensible */
 153    if (LastHost != Host || LastPort != Port)
 154    {
 155       Owner->Status(_("Connecting to %s"),Host.c_str());
 156
 157       // Free the old address structure
 158       if (LastHostAddr != 0)
 159       {
 160          freeaddrinfo(LastHostAddr);
 161          LastHostAddr = 0;
 162          LastUsed = 0;
 163       }
 164
 165       // We only understand SOCK_STREAM sockets.
 166       struct addrinfo Hints;
 167       memset(&Hints,0,sizeof(Hints));
 168       Hints.ai_socktype = SOCK_STREAM;
 169       Hints.ai_flags = AI_ADDRCONFIG;
 170       Hints.ai_protocol = 0;
 171
 172       if(_config->FindB("Acquire::ForceIPv4", false) == true)
 173          Hints.ai_family = AF_INET;
 174       else if(_config->FindB("Acquire::ForceIPv6", false) == true)
 175          Hints.ai_family = AF_INET6;
 176       else
 177          Hints.ai_family = AF_UNSPEC;
 178
 179       // if we couldn't resolve the host before, we don't try now
 180       if(bad_addr.find(Host) != bad_addr.end())
 181          return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 182
 183       // Resolve both the host and service simultaneously
 184       while (1)
 185       {
 186          int Res;
 187          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 188              LastHostAddr == 0)
 189          {
 190             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 191             {
 192                if (DefPort != 0)
 193                {
 194                   snprintf(ServStr, sizeof(ServStr), "%i", DefPort);
 195                   DefPort = 0;
 196                   continue;
 197                }
 198                bad_addr.insert(bad_addr.begin(), Host);
 199                Owner->SetFailReason("ResolveFailure");
 200                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 201             }
 202
 203             if (Res == EAI_AGAIN)
 204             {
 205                Owner->SetFailReason("TmpResolveFailure");
 206                return _error->Error(_("Temporary failure resolving '%s'"),
 207                                     Host.c_str());
 208             }
 209             if (Res == EAI_SYSTEM)
 210                return _error->Errno("getaddrinfo", _("System error resolving '%s:%s'"),
 211                                       Host.c_str(),ServStr);
 212             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i - %s)"),
 213                                  Host.c_str(),ServStr,Res,gai_strerror(Res));
 214          }
 215          break;
 216       }
 217
 218       LastHost = Host;
 219       LastPort = Port;
 220    }
 221
 222    // When we have an IP rotation stay with the last IP.
 223    struct addrinfo *CurHost = LastHostAddr;
 224    if (LastUsed != 0)
 225        CurHost = LastUsed;
 226
 227    while (CurHost != 0)
 228    {
 229       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 230       {
 231          LastUsed = CurHost;
 232          return true;
 233       }
 234       close(Fd);
 235       Fd = -1;
 236
 237       // Ignore UNIX domain sockets
 238       do
 239       {
 240          CurHost = CurHost->ai_next;
 241       }
 242       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 243
 244       /* If we reached the end of the search list then wrap around to the
 245          start */
 246       if (CurHost == 0 && LastUsed != 0)
 247          CurHost = LastHostAddr;
 248
 249       // Reached the end of the search cycle
 250       if (CurHost == LastUsed)
 251          break;
 252
 253       if (CurHost != 0)
 254          _error->Discard();
 255    }
 256
 257    if (_error->PendingError() == true)
 258       return false;
 259    return _error->Error(_("Unable to connect to %s:%s:"),Host.c_str(),ServStr);
 260 }
 261                                                                         /*}}}*/
 262 // Connect - Connect to a server                                        /*{{{*/
 263 // ---------------------------------------------------------------------
 264 /* Performs a connection to the server (including SRV record lookup) */
 265 bool Connect(std::string Host,int Port,const char *Service,
 266                             int DefPort,int &Fd,
 267                             unsigned long TimeOut,pkgAcqMethod *Owner)
 268 {
 269    if (_error->PendingError() == true)
 270       return false;
 271
 272    if(LastHost != Host || LastPort != Port)
 273    {
 274       SrvRecords.clear();
 275       if (_config->FindB("Acquire::EnableSrvRecords", true) == true)
 276          GetSrvRecords(Host, DefPort, SrvRecords);
 277    }
 278    // we have no SrvRecords for this host, connect right away
 279    if(SrvRecords.size() == 0)
 280       return ConnectToHostname(Host, Port, Service, DefPort, Fd,
 281                                     TimeOut, Owner);
 282
 283    // try to connect in the priority order of the srv records
 284    while(SrvRecords.size() > 0)
 285    {
 286       Host = PopFromSrvRecs(SrvRecords).target;
 287       if(ConnectToHostname(Host, Port, Service, DefPort, Fd, TimeOut, Owner))
 288          return true;
 289
 290       // we couldn't connect to this one, use the next
 291       SrvRecords.erase(SrvRecords.begin());
 292    }
 293
 294    return false;
 295 }