developer.intra2net.com Git - libt2n/blob - src/socket_client.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2006 by Gerd v. Egidy                                   *
   3  *   gve@intra2net.com                                                     *
   4  *                                                                         *
   5  *   This library is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU Lesser General Public License version   *
   7  *   2.1 as published by the Free Software Foundation.                     *
   8  *                                                                         *
   9  *   This library is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU Lesser General Public License for more details.                   *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU Lesser General Public      *
  15  *   License along with this program; if not, write to the                 *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  18  ***************************************************************************/
  19
  20 #include <stdio.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <sys/un.h>
  27 #include <sys/time.h>
  28 #include <arpa/inet.h>
  29 #include <netinet/in.h>
  30 #include <netdb.h>
  31 #include <fcntl.h>
  32 #include <time.h>
  33 #include <pwd.h>
  34 #include <grp.h>
  35
  36 #include <sstream>
  37
  38 #include "socket_client.hxx"
  39 #include "t2n_exception.hxx"
  40 #include "log.hxx"
  41
  42 using namespace std;
  43
  44 namespace libt2n
  45 {
  46
  47 /// returns a closed connection if connection could not be established, call get_last_error_msg() for details
  48 socket_client_connection::socket_client_connection(int _port, const std::string& _server,
  49             long long _connect_timeout_usec, int _max_retries,
  50             std::ostream *_logstream, log_level_values _log_level)
  51     : client_connection(), socket_handler(0,tcp_s)
  52 {
  53     max_retries=_max_retries;
  54     connect_timeout_usec=_connect_timeout_usec;
  55
  56     server=_server;
  57     port=_port;
  58
  59     set_logging(_logstream,_log_level);
  60
  61     try
  62     {
  63         tcp_connect(max_retries);
  64     }
  65     catch (t2n_communication_error &e)
  66     {
  67         lastErrorMsg=e.what();
  68         LOGSTREAM(debug,"tcp connect error: " << lastErrorMsg);
  69         close();
  70     }
  71
  72     if (!connection::is_closed())
  73         do_callbacks(new_connection);
  74 }
  75
  76 /// returns a closed connection if connection could not be established, call get_last_error_msg() for details
  77 socket_client_connection::socket_client_connection(const std::string& _path,
  78             long long _connect_timeout_usec, int _max_retries,
  79             std::ostream *_logstream, log_level_values _log_level)
  80     : client_connection(), socket_handler(0,unix_s)
  81 {
  82     max_retries=_max_retries;
  83     connect_timeout_usec=_connect_timeout_usec;
  84
  85     path=_path;
  86
  87     set_logging(_logstream,_log_level);
  88
  89     try
  90     {
  91         unix_connect(max_retries);
  92     }
  93     catch (t2n_communication_error &e)
  94     {
  95         lastErrorMsg=e.what();
  96         LOGSTREAM(debug,"unix connect error: " << lastErrorMsg);
  97         close();
  98     }
  99
 100     if (!connection::is_closed())
 101         do_callbacks(new_connection);
 102 }
 103
 104 /// establish a connection via tcp
 105 void socket_client_connection::tcp_connect(int max_retries)
 106 {
 107     struct sockaddr_in sock_addr;
 108
 109     sock_addr.sin_family = AF_INET;
 110     sock_addr.sin_port = htons(port);
 111
 112     // find the target ip
 113     if (inet_aton(server.c_str(),&sock_addr.sin_addr)==0)
 114     {
 115         struct hostent *server_hent;
 116         server_hent=gethostbyname(server.c_str());
 117         if (server_hent == NULL)
 118             throw t2n_connect_error(string("can't find server ")+server);
 119
 120         memcpy(&sock_addr.sin_addr,server_hent->h_addr_list[0],sizeof(sock_addr.sin_addr));
 121     }
 122
 123     sock = socket(PF_INET, SOCK_STREAM, 0);
 124     if (!sock)
 125         throw t2n_connect_error(string("socket() error: ")+strerror(errno));
 126
 127     try
 128     {
 129         connect_with_timeout((struct sockaddr *) &sock_addr,sizeof(sock_addr));
 130     }
 131     catch (t2n_connect_error &e)
 132     {
 133         // recurse if retries left
 134         if (max_retries > 0)
 135         {
 136             LOGSTREAM(debug,"retrying connect after connect error");
 137             tcp_connect(max_retries-1);
 138         }
 139         else
 140             throw t2n_connect_error("no more retries left after connect error");
 141     }
 142 }
 143
 144 /// establish a connection via unix-socket
 145 void socket_client_connection::unix_connect(int max_retries)
 146 {
 147     struct sockaddr_un unix_addr;
 148
 149     unix_addr.sun_family = AF_UNIX;
 150     strcpy (unix_addr.sun_path, path.c_str());
 151
 152     sock = socket(PF_UNIX, SOCK_STREAM, 0);
 153     if (!sock)
 154         throw t2n_connect_error(string("socket() error: ")+strerror(errno));
 155
 156     try
 157     {
 158         connect_with_timeout((struct sockaddr *) &unix_addr, sizeof(unix_addr));
 159     }
 160     catch (t2n_connect_error &e)
 161     {
 162         // recurse if retries left
 163         if (max_retries > 0)
 164         {
 165             LOGSTREAM(debug,"retrying connect after connect error");
 166             unix_connect(max_retries-1);
 167         }
 168         else
 169             throw t2n_connect_error("no more retries left after connect error");
 170     }
 171 }
 172
 173 /// execute a connect on a prepared socket (tcp or unix) respecting timeouts
 174 void socket_client_connection::connect_with_timeout(struct sockaddr *sock_addr,unsigned int sockaddr_size)
 175 {
 176     set_socket_options(sock);
 177
 178    /* non-blocking mode */
 179     int flflags;
 180     flflags=fcntl(sock,F_GETFL,0);
 181     if (flflags < 0)
 182         EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
 183
 184     flflags &= (O_NONBLOCK ^ 0xFFFF);
 185     if (fcntl(sock,F_SETFL,flflags) < 0)
 186         EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
 187
 188
 189     LOGSTREAM(debug,"connect_with_timeout()");
 190     int ret=::connect(sock,sock_addr, sockaddr_size);
 191
 192     if (ret < 0)
 193     {
 194         if (errno==EINPROGRESS)
 195         {
 196             LOGSTREAM(debug,"connect_with_timeout(): EINPROGRESS");
 197
 198             /* set timeout */
 199             struct timeval tval;
 200             struct timeval *timeout_ptr;
 201
 202             if (connect_timeout_usec == -1)
 203                 timeout_ptr = NULL;
 204             else
 205             {
 206                 timeout_ptr = &tval;
 207
 208                 // convert timeout from long long usec to int sec + int usec
 209                 tval.tv_sec = connect_timeout_usec / 1000000;
 210                 tval.tv_usec = connect_timeout_usec % 1000000;
 211             }
 212
 213             fd_set connect_socket_set;
 214             FD_ZERO(&connect_socket_set);
 215             FD_SET(sock,&connect_socket_set);
 216
 217             int ret;
 218             while ((ret=select(FD_SETSIZE, NULL, &connect_socket_set, NULL, timeout_ptr)) &&
 219                     ret < 0 && errno==EINTR);
 220
 221             if (ret < 0)
 222                 throw t2n_connect_error(string("connect() error (select): ")+strerror(errno));
 223
 224             socklen_t sopt=sizeof(int);
 225             int valopt;
 226             ret=getsockopt(sock, SOL_SOCKET, SO_ERROR, (void*)(&valopt), &sopt);
 227             if (ret < 0 || valopt)
 228                 throw t2n_connect_error(string("connect() error (getsockopt): ")+strerror(errno));
 229         }
 230         else
 231             throw t2n_connect_error(string("connect() error: ")+strerror(errno));
 232     }
 233
 234     LOGSTREAM(debug,"connect_with_timeout(): success");
 235 }
 236
 237 void socket_client_connection::close()
 238 {
 239     if (!client_connection::is_closed())
 240     {
 241         socket_handler::close();
 242         client_connection::close();
 243     }
 244 }
 245
 246 /** @brief try to reconnect the current connection with the same connection credentials (host and port or path)
 247
 248     @note will throw an exeption if reconnecting not possible
 249 */
 250 void socket_client_connection::reconnect()
 251 {
 252     LOGSTREAM(debug,"reconnect()");
 253
 254     // close the current connection if still open
 255     close();
 256
 257     socket_type_value type=get_type();
 258
 259     if (type == tcp_s)
 260         tcp_connect(max_retries);
 261     else if (type == unix_s)
 262         unix_connect(max_retries);
 263
 264     // connection is open now, otherwise an execption would have been thrown
 265     reopen();
 266
 267     LOGSTREAM(debug,"reconnect() done, client_connection::is_closed() now " << client_connection::is_closed());
 268 }
 269
 270 }