methods/connect.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: connect.cc,v 1.8 2002/02/28 03:51:55 jgg Exp $
   4 /* ######################################################################
   5
   6    Connect - Replacement connect call
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10 // Include Files                                                        /*{{{*/
  11 #include "connect.h"
  12 #include <apt-pkg/error.h>
  13 #include <apt-pkg/fileutl.h>
  14
  15 #include <stdio.h>
  16 #include <errno.h>
  17 #include <unistd.h>
  18
  19 // Internet stuff
  20 #include <netinet/in.h>
  21 #include <sys/socket.h>
  22 #include <arpa/inet.h>
  23 #include <netdb.h>
  24
  25 #include "rfc2553emu.h"
  26                                                                         /*}}}*/
  27
  28 static string LastHost;
  29 static int LastPort = 0;
  30 static struct addrinfo *LastHostAddr = 0;
  31 static struct addrinfo *LastUsed = 0;
  32
  33 // RotateDNS - Select a new server from a DNS rotation                  /*{{{*/
  34 // ---------------------------------------------------------------------
  35 /* This is called during certain errors in order to recover by selecting a
  36    new server */
  37 void RotateDNS()
  38 {
  39    if (LastUsed != 0 && LastUsed->ai_next != 0)
  40       LastUsed = LastUsed->ai_next;
  41    else
  42       LastUsed = LastHostAddr;
  43 }
  44                                                                         /*}}}*/
  45 // DoConnect - Attempt a connect operation                              /*{{{*/
  46 // ---------------------------------------------------------------------
  47 /* This helper function attempts a connection to a single address. */
  48 static bool DoConnect(struct addrinfo *Addr,string Host,
  49                       unsigned long TimeOut,int &Fd,pkgAcqMethod *Owner)
  50 {
  51    // Show a status indicator
  52    char Name[NI_MAXHOST];
  53    char Service[NI_MAXSERV];
  54
  55    Name[0] = 0;
  56    Service[0] = 0;
  57    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
  58                Name,sizeof(Name),Service,sizeof(Service),
  59                NI_NUMERICHOST|NI_NUMERICSERV);
  60    Owner->Status("Connecting to %s (%s)",Host.c_str(),Name);
  61
  62    /* If this is an IP rotation store the IP we are using.. If something goes
  63       wrong this will get tacked onto the end of the error message */
  64    if (LastHostAddr->ai_next != 0)
  65    {
  66       char Name2[NI_MAXHOST + NI_MAXSERV + 10];
  67       snprintf(Name2,sizeof(Name2),"[IP: %s %s]",Name,Service);
  68       Owner->SetFailExtraMsg(string(Name2));
  69    }
  70    else
  71       Owner->SetFailExtraMsg("");
  72
  73    // Get a socket
  74    if ((Fd = socket(Addr->ai_family,Addr->ai_socktype,
  75                     Addr->ai_protocol)) < 0)
  76       return _error->Errno("socket","Could not create a socket for %s (f=%u t=%u p=%u)",
  77                            Name,Addr->ai_family,Addr->ai_socktype,Addr->ai_protocol);
  78
  79    SetNonBlock(Fd,true);
  80    if (connect(Fd,Addr->ai_addr,Addr->ai_addrlen) < 0 &&
  81        errno != EINPROGRESS)
  82       return _error->Errno("connect","Cannot initiate the connection "
  83                            "to %s:%s (%s).",Host.c_str(),Service,Name);
  84
  85    /* This implements a timeout for connect by opening the connection
  86       nonblocking */
  87    if (WaitFd(Fd,true,TimeOut) == false)
  88       return _error->Error("Could not connect to %s:%s (%s), "
  89                            "connection timed out",Host.c_str(),Service,Name);
  90
  91    // Check the socket for an error condition
  92    unsigned int Err;
  93    unsigned int Len = sizeof(Err);
  94    if (getsockopt(Fd,SOL_SOCKET,SO_ERROR,&Err,&Len) != 0)
  95       return _error->Errno("getsockopt","Failed");
  96
  97    if (Err != 0)
  98    {
  99       errno = Err;
 100       return _error->Errno("connect","Could not connect to %s:%s (%s).",Host.c_str(),
 101                            Service,Name);
 102    }
 103
 104    return true;
 105 }
 106                                                                         /*}}}*/
 107 // Connect - Connect to a server                                        /*{{{*/
 108 // ---------------------------------------------------------------------
 109 /* Performs a connection to the server */
 110 bool Connect(string Host,int Port,const char *Service,int DefPort,int &Fd,
 111              unsigned long TimeOut,pkgAcqMethod *Owner)
 112 {
 113    if (_error->PendingError() == true)
 114       return false;
 115
 116    // Convert the port name/number
 117    char ServStr[300];
 118    if (Port != 0)
 119       snprintf(ServStr,sizeof(ServStr),"%u",Port);
 120    else
 121       snprintf(ServStr,sizeof(ServStr),"%s",Service);
 122
 123    /* We used a cached address record.. Yes this is against the spec but
 124       the way we have setup our rotating dns suggests that this is more
 125       sensible */
 126    if (LastHost != Host || LastPort != Port)
 127    {
 128       Owner->Status("Connecting to %s",Host.c_str());
 129
 130       // Free the old address structure
 131       if (LastHostAddr != 0)
 132       {
 133          freeaddrinfo(LastHostAddr);
 134          LastHostAddr = 0;
 135          LastUsed = 0;
 136       }
 137
 138       // We only understand SOCK_STREAM sockets.
 139       struct addrinfo Hints;
 140       memset(&Hints,0,sizeof(Hints));
 141       Hints.ai_socktype = SOCK_STREAM;
 142       Hints.ai_protocol = 0;
 143
 144       // Resolve both the host and service simultaneously
 145       while (1)
 146       {
 147          int Res;
 148          if ((Res = getaddrinfo(Host.c_str(),ServStr,&Hints,&LastHostAddr)) != 0 ||
 149              LastHostAddr == 0)
 150          {
 151             if (Res == EAI_NONAME || Res == EAI_SERVICE)
 152             {
 153                if (DefPort != 0)
 154                {
 155                   snprintf(ServStr,sizeof(ServStr),"%u",DefPort);
 156                   DefPort = 0;
 157                   continue;
 158                }
 159                return _error->Error("Could not resolve '%s'",Host.c_str());
 160             }
 161
 162             if (Res == EAI_AGAIN)
 163                return _error->Error("Temporary failure resolving '%s'",
 164                                     Host.c_str());
 165             return _error->Error("Something wicked happened resolving '%s:%s' (%i)",
 166                                  Host.c_str(),ServStr,Res);
 167          }
 168          break;
 169       }
 170
 171       LastHost = Host;
 172       LastPort = Port;
 173    }
 174
 175    // When we have an IP rotation stay with the last IP.
 176    struct addrinfo *CurHost = LastHostAddr;
 177    if (LastUsed != 0)
 178        CurHost = LastUsed;
 179
 180    while (CurHost != 0)
 181    {
 182       if (DoConnect(CurHost,Host,TimeOut,Fd,Owner) == true)
 183       {
 184          LastUsed = CurHost;
 185          return true;
 186       }
 187       close(Fd);
 188       Fd = -1;
 189
 190       // Ignore UNIX domain sockets
 191       do
 192       {
 193          CurHost = CurHost->ai_next;
 194       }
 195       while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
 196
 197       /* If we reached the end of the search list then wrap around to the
 198          start */
 199       if (CurHost == 0 && LastUsed != 0)
 200          CurHost = LastHostAddr;
 201
 202       // Reached the end of the search cycle
 203       if (CurHost == LastUsed)
 204          break;
 205
 206       if (CurHost != 0)
 207          _error->Discard();
 208    }
 209
 210    if (_error->PendingError() == true)
 211       return false;
 212    return _error->Error("Unable to connect to %s %s:",Host.c_str(),ServStr);
 213 }
 214                                                                         /*}}}*/