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       else if (errno == ETIMEDOUT)
 120          Owner->SetFailExtraMsg("\nFailReason: ConnectionTimedOut");
 121       bad_addr.insert(bad_addr.begin(), string(Name));
 122       return _error->Errno("connect",_("Could not connect to %s:%s (%s)."),Host.c_str(),
 123                            Service,Name);
 124    }
 125
 126    return true;
 127 }
 128                                                                         /*}}}*/
 129 // Connect - Connect to a server                                        /*{{{*/
 130 // ---------------------------------------------------------------------
 131 /* Performs a connection to the server */
 132 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
 133              unsigned long TimeOut,pkgAcqMethod *Owner)
 134 {
 135    if (_error->PendingError() == true)
 136       return false;
 137
 138    // Convert the port name/number
 139    char ServStr[300];
 140    if (Port != 0)
 141       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 142    else
 143       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 144
 145    /* We used a cached address record.. Yes this is against the spec but
 146       the way we have setup our rotating dns suggests that this is more
 147       sensible */
 148    if (LastHost != Host || LastPort != Port)
 149    {
 150       Owner->Status(_("Connecting to %s"),Host.c_str());
 151
 152       // Free the old address structure
 153       if (LastHostAddr != 0)
 154       {
 155          freeaddrinfo(LastHostAddr);
 156          LastHostAddr = 0;
 157          LastUsed = 0;
 158       }
 159
 160       // We only understand SOCK_STREAM sockets.
 161       struct addrinfo Hints;
 162       memset(&Hints,0,sizeof(Hints));
 163       Hints.ai_socktype = SOCK_STREAM;
 164       Hints.ai_flags = AI_ADDRCONFIG;
 165       Hints.ai_protocol = 0;
 166
 167       // if we couldn't resolve the host before, we don't try now
 168       if(bad_addr.find(Host) != bad_addr.end())
 169          return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 170
 171       // Resolve both the host and service simultaneously
 172       while (1)
 173       {
 174          int Res;
 175          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 176              LastHostAddr == 0)
 177          {
 178             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 179             {
 180                if (DefPort != 0)
 181                {
 182                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 183                   DefPort = 0;
 184                   continue;
 185                }
 186                bad_addr.insert(bad_addr.begin(), Host);
 187                Owner->SetFailExtraMsg("\nFailReason: ResolveFailure");
 188                return _error->Error(_("Could not resolve '%s'"),Host.c_str());
 189             }
 190
 191             if (Res == EAI_AGAIN)
 192             {
 193                Owner->SetFailExtraMsg("\nFailReason: TmpResolveFailure");
 194                return _error->Error(_("Temporary failure resolving '%s'"),
 195                                     Host.c_str());
 196             }
 197             return _error->Error(_("Something wicked happened resolving '%s:%s' (%i - %s)"),
 198                                  Host.c_str(),ServStr,Res,gai_strerror(Res));
 199          }
 200          break;
 201       }
 202
 203       LastHost = Host;
 204       LastPort = Port;
 205    }
 206
 207    // When we have an IP rotation stay with the last IP.
 208    struct addrinfo *CurHost = LastHostAddr;
 209    if (LastUsed != 0)
 210        CurHost = LastUsed;
 211
 212    while (CurHost != 0)
 213    {
 214       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 215       {
 216          LastUsed = CurHost;
 217          return true;
 218       }
 219       close(Fd);
 220       Fd = -1;
 221
 222       // Ignore UNIX domain sockets
 223       do
 224       {
 225          CurHost = CurHost->ai_next;
 226       }
 227       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 228
 229       /* If we reached the end of the search list then wrap around to the
 230          start */
 231       if (CurHost == 0 && LastUsed != 0)
 232          CurHost = LastHostAddr;
 233
 234       // Reached the end of the search cycle
 235       if (CurHost == LastUsed)
 236          break;
 237
 238       if (CurHost != 0)
 239          _error->Discard();
 240    }
 241
 242    if (_error->PendingError() == true)
 243       return false;
 244    return _error->Error(_("Unable to connect to %s:%s:"),Host.c_str(),ServStr);
 245 }
 246                                                                         /*}}}*/