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         // FIXME: Don't call virtual function in constructor. Currently not dangerous but bad design.
  70         close();
  71     }
  72
  73     if (!connection::is_closed())
  74         do_callbacks(new_connection);
  75 }
  76
  77 /// returns a closed connection if connection could not be established, call get_last_error_msg() for details
  78 socket_client_connection::socket_client_connection(const std::string& _path,
  79             long long _connect_timeout_usec, int _max_retries,
  80             std::ostream *_logstream, log_level_values _log_level)
  81     : client_connection(), socket_handler(0,unix_s)
  82 {
  83     max_retries=_max_retries;
  84     connect_timeout_usec=_connect_timeout_usec;
  85
  86     path=_path;
  87
  88     set_logging(_logstream,_log_level);
  89
  90     try
  91     {
  92         unix_connect(max_retries);
  93     }
  94     catch (t2n_communication_error &e)
  95     {
  96         lastErrorMsg=e.what();
  97         LOGSTREAM(debug,"unix connect error: " << lastErrorMsg);
  98         // FIXME: Don't call virtual function in constructor. Currently not dangerous
  99         close();
 100     }
 101
 102     if (!connection::is_closed())
 103         do_callbacks(new_connection);
 104 }
 105
 106 /**
 107  * Destructor. Closes an open connection.
 108  */
 109 socket_client_connection::~socket_client_connection()
 110 {
 111     // Destructor of socket_handler will close the socket!
 112 }
 113
 114
 115 /// establish a connection via tcp
 116 void socket_client_connection::tcp_connect(int max_retries)
 117 {
 118     struct sockaddr_in sock_addr;
 119
 120     sock_addr.sin_family = AF_INET;
 121     sock_addr.sin_port = htons(port);
 122
 123     // find the target ip
 124     if (inet_aton(server.c_str(),&sock_addr.sin_addr)==0)
 125     {
 126         struct hostent *server_hent;
 127         server_hent=gethostbyname(server.c_str());
 128         if (server_hent == NULL)
 129             throw t2n_connect_error(string("can't find server ")+server);
 130
 131         memcpy(&sock_addr.sin_addr,server_hent->h_addr_list[0],sizeof(sock_addr.sin_addr));
 132     }
 133
 134     sock = socket(PF_INET, SOCK_STREAM, 0);
 135     if (!sock)
 136         throw t2n_connect_error(string("socket() error: ")+strerror(errno));
 137
 138     try
 139     {
 140         connect_with_timeout((struct sockaddr *) &sock_addr,sizeof(sock_addr));
 141     }
 142     catch (t2n_connect_error &e)
 143     {
 144         // recurse if retries left
 145         if (max_retries > 0)
 146         {
 147             LOGSTREAM(debug,"retrying connect after connect error");
 148             tcp_connect(max_retries-1);
 149         }
 150         else
 151             throw t2n_connect_error("no more retries left after connect error");
 152     }
 153 }
 154
 155 /// establish a connection via unix-socket
 156 void socket_client_connection::unix_connect(int max_retries)
 157 {
 158     struct sockaddr_un unix_addr;
 159
 160     unix_addr.sun_family = AF_UNIX;
 161     strcpy (unix_addr.sun_path, path.c_str());
 162
 163     sock = socket(PF_UNIX, SOCK_STREAM, 0);
 164     if (!sock)
 165         throw t2n_connect_error(string("socket() error: ")+strerror(errno));
 166
 167     try
 168     {
 169         connect_with_timeout((struct sockaddr *) &unix_addr, sizeof(unix_addr));
 170     }
 171     catch (t2n_connect_error &e)
 172     {
 173         // recurse if retries left
 174         if (max_retries > 0)
 175         {
 176             LOGSTREAM(debug,"retrying connect after connect error");
 177             unix_connect(max_retries-1);
 178         }
 179         else
 180             throw t2n_connect_error("no more retries left after connect error");
 181     }
 182 }
 183
 184 /// execute a connect on a prepared socket (tcp or unix) respecting timeouts
 185 void socket_client_connection::connect_with_timeout(struct sockaddr *sock_addr,unsigned int sockaddr_size)
 186 {
 187     set_socket_options(sock);
 188
 189    /* non-blocking mode */
 190     int flflags;
 191     flflags=fcntl(sock,F_GETFL,0);
 192     if (flflags < 0)
 193         EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
 194
 195     flflags &= (O_NONBLOCK ^ 0xFFFF);
 196     if (fcntl(sock,F_SETFL,flflags) < 0)
 197         EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
 198
 199
 200     LOGSTREAM(debug,"connect_with_timeout()");
 201     int ret=::connect(sock,sock_addr, sockaddr_size);
 202
 203     if (ret < 0)
 204     {
 205         if (errno==EINPROGRESS)
 206         {
 207             LOGSTREAM(debug,"connect_with_timeout(): EINPROGRESS");
 208
 209             /* set timeout */
 210             struct timeval tval;
 211             struct timeval *timeout_ptr;
 212
 213             if (connect_timeout_usec == -1)
 214                 timeout_ptr = NULL;
 215             else
 216             {
 217                 timeout_ptr = &tval;
 218
 219                 // convert timeout from long long usec to int sec + int usec
 220                 tval.tv_sec = connect_timeout_usec / 1000000;
 221                 tval.tv_usec = connect_timeout_usec % 1000000;
 222             }
 223
 224             fd_set connect_socket_set;
 225             FD_ZERO(&connect_socket_set);
 226             FD_SET(sock,&connect_socket_set);
 227
 228             int ret;
 229             while ((ret=select(FD_SETSIZE, NULL, &connect_socket_set, NULL, timeout_ptr)) &&
 230                     ret < 0 && errno==EINTR);
 231
 232             if (ret < 0)
 233                 throw t2n_connect_error(string("connect() error (select): ")+strerror(errno));
 234
 235             socklen_t sopt=sizeof(int);
 236             int valopt;
 237             ret=getsockopt(sock, SOL_SOCKET, SO_ERROR, (void*)(&valopt), &sopt);
 238             if (ret < 0 || valopt)
 239                 throw t2n_connect_error(string("connect() error (getsockopt): ")+strerror(errno));
 240         }
 241         else
 242             throw t2n_connect_error(string("connect() error: ")+strerror(errno));
 243     }
 244
 245     LOGSTREAM(debug,"connect_with_timeout(): success");
 246 }
 247
 248 void socket_client_connection::close()
 249 {
 250     if (!client_connection::is_closed())
 251     {
 252         socket_handler::close();
 253         client_connection::close();
 254     }
 255 }
 256
 257 /** @brief try to reconnect the current connection with the same connection credentials (host and port or path)
 258
 259     @note will throw an exeption if reconnecting not possible
 260 */
 261 void socket_client_connection::reconnect()
 262 {
 263     LOGSTREAM(debug,"reconnect()");
 264
 265     // close the current connection if still open
 266     close();
 267
 268     socket_type_value type=get_type();
 269
 270     if (type == tcp_s)
 271         tcp_connect(max_retries);
 272     else if (type == unix_s)
 273         unix_connect(max_retries);
 274
 275     // connection is open now, otherwise an execption would have been thrown
 276     reopen();
 277
 278     LOGSTREAM(debug,"reconnect() done, client_connection::is_closed() now " << client_connection::is_closed());
 279 }
 280
 281 }