1 /***************************************************************************
2 * Copyright (C) 2006 by Gerd v. Egidy *
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. *
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. *
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 ***************************************************************************/
24 #include <sys/types.h>
25 #include <sys/socket.h>
28 #include <arpa/inet.h>
29 #include <netinet/in.h>
40 #include "socket_handler.hxx"
41 #include "t2n_exception.hxx"
49 socket_handler::socket_handler(int _sock, socket_type_value _socket_type)
51 , recv_buffer_size( default_recv_buffer_size )
52 , write_block_size( default_write_block_size )
53 , write_timeout( default_write_timeout )
54 , socket_type(_socket_type)
59 * Destructor. Closes open socket
61 socket_handler::~socket_handler()
65 shutdown(sock,SHUT_RDWR);
72 /// close the underlying socket connection. Don't call directly, use the version provided
73 /// by the connection class you are using.
74 void socket_handler::close()
76 LOGSTREAM(debug,"close connection");
78 shutdown(sock,SHUT_RDWR);
84 /// set options like fast reuse and keepalive every socket should have
85 void socket_handler::set_socket_options(int sock)
89 /* fast reuse enable */
90 if (setsockopt(sock,SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i)) < 0)
91 EXCEPTIONSTREAM(error,t2n_communication_error,"error setting socket option: " << strerror(errno));
93 /* keepalive enable */
94 if (setsockopt(sock,SOL_SOCKET, SO_KEEPALIVE, &i, sizeof(i)) < 0)
95 EXCEPTIONSTREAM(error,t2n_communication_error,"error setting socket option: " << strerror(errno));
99 fdflags=fcntl(sock,F_GETFD, 0);
101 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
103 fdflags |= FD_CLOEXEC;
104 if (fcntl(sock,F_SETFD,fdflags) < 0)
105 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
107 /* non-blocking mode */
109 flflags=fcntl(sock,F_GETFL,0);
111 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
113 flflags |= O_NONBLOCK;
114 if (fcntl(sock,F_SETFL,flflags) < 0)
115 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
118 /// is the underlying socket connection still open?
119 bool socket_handler::is_closed()
121 int r=fcntl(sock,F_GETFL);
123 return !(r & O_ACCMODE);
128 * @brief set a new size for the receive buffer.
129 * @param new_recv_buffer_size the new size for the receive buffer.
131 * The receive buffer determines the amount of data which is tried to read at once
132 * from the underlying socket.
134 * The value is normalized to be at least 512 bytes and at max 32K bytes.
136 void socket_handler::set_recv_buffer_size(unsigned int new_recv_buffer_size)
138 recv_buffer_size= std::max( 512u, std::min( 32u * 1024u, new_recv_buffer_size ));
143 * @brief set new size for the data chunks when writeing.
144 * @param new_write_block_size the new chunk size.
146 * The write block size determines the amount of data which is tried to write
147 * to the socket when data needs to be sended.
148 * Since writing data is done in a loop, this does not limit the amunt of data which can
151 * The value is normalized to be at least 512 bytes and at max 32K bytes.
153 void socket_handler::set_write_block_size(unsigned int new_write_block_size)
155 write_block_size= std::max( 512u, std::min( 32u * 1024u, new_write_block_size ));
160 * @brief set new timeout for writing a block
161 * @param new_write_timeout the new timeout in usecs, -1: wait endless
163 * The write timeout determines the maximum amount of time that is waited
164 * between writing each block. If the timeout is exceeded, write will
165 * throw t2n_transfer_error
167 void socket_handler::set_write_timeout(long long new_write_timeout)
169 write_block_size=new_write_timeout;
173 /** @brief check if new data is waiting on the raw socket
174 @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
177 @param[out] usec_timeout_remaining microseconds from the timeout that were not used
179 bool socket_handler::data_waiting(long long usec_timeout,long long* usec_timeout_remaining)
182 fd_set active_fd_set;
183 FD_ZERO (&active_fd_set);
184 FD_SET (sock, &active_fd_set);
188 struct timeval *timeout_ptr;
190 if (usec_timeout == -1)
196 // convert timeout from long long usec to int sec + int usec
197 tval.tv_sec = usec_timeout / 1000000;
198 tval.tv_usec = usec_timeout % 1000000;
201 int ret=select (FD_SETSIZE, &active_fd_set, NULL, NULL, timeout_ptr);
203 // return the timeout we did not use
204 // todo: this is linux specific according to man 2 select
205 if (usec_timeout > 0 && usec_timeout_remaining != NULL)
206 *usec_timeout_remaining=(tval.tv_sec*1000000)+tval.tv_usec;
214 /** @brief read data from the raw socket and copy it into the provided buffer
215 @param buffer the buffer where to append the new data
216 @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
219 @param[out] usec_timeout_remaining microseconds from the timeout that were not used
221 bool socket_handler::fill_buffer(std::string& buffer, long long usec_timeout, long long *usec_timeout_remaining)
223 // fast path for timeout==0
224 if (usec_timeout==0 || data_waiting(usec_timeout,usec_timeout_remaining))
225 return fill_buffer(buffer);
230 /** @brief read data from the raw socket and copy it into the provided buffer. Returns
231 instantly if no data is waiting.
232 @param buffer the buffer where to append the new data
234 bool socket_handler::fill_buffer(std::string& buffer)
236 bool try_again=false;
238 char socket_buffer[recv_buffer_size];
240 int nbytes = read (sock, socket_buffer, recv_buffer_size);
245 return false; // no data was waiting
246 else if (errno == EINTR)
248 // interrupted, try again
249 LOGSTREAM(debug,"EINTR received on read(), trying again");
253 EXCEPTIONSTREAM(error,t2n_transfer_error,"error reading from socket : " << strerror(errno));
257 if (nbytes == 0 && !try_again)
259 LOGSTREAM(debug,"0 bytes received on read(), closing connection");
264 // Data read -> store it
267 buffer.append(socket_buffer,nbytes);
268 LOGSTREAM(debug,nbytes << " bytes read");
271 // more data waiting -> recurse
281 /// writes raw data to the socket. Don't use directly, use the write() function provided by the
282 /// connection because it encapsulates the data.
283 void socket_handler::socket_write(const std::string& data)
285 unsigned int offset = 0;
286 while (offset < data.size())
288 unsigned int write_size=write_block_size;
290 if (offset+write_size > data.size())
291 write_size = data.size()-offset;
294 while ((rtn=::write(sock, data.data()+offset, write_size)) == -1 &&
295 (errno == EAGAIN || errno == EINTR))
297 wait_ready_to_write(sock,write_timeout);
298 LOGSTREAM(debug,"resuming write() call after EAGAIN or EINTR");
302 EXCEPTIONSTREAM(error,t2n_transfer_error,"write() returned " << strerror(errno));
303 else if (rtn != write_size)
305 LOGSTREAM(debug,"write() wrote " << rtn << " bytes, should have been "
306 << write_size << " (complete: " << data.size() << ")");
311 offset += write_size;
314 LOGSTREAM(debug,"wrote " << data.size() << " bytes");
317 } // eo socket_handler::socket_write(const std::string&)
319 /// wait until the socket is ready to write again
320 void socket_handler::wait_ready_to_write(int socket, long long write_block_timeout)
322 // prepare socket sets
324 fd_set except_set[1];
327 FD_SET(socket, write_set);
328 FD_SET(socket, except_set);
330 // prepare timeout struct
332 struct timeval *timeout_ptr;
334 if (write_block_timeout == -1)
340 // convert timeout from long long usec to int sec + int usec
341 tval.tv_sec = write_block_timeout / 1000000;
342 tval.tv_usec = write_block_timeout % 1000000;
345 // let's wait for the socket to become writable again...
347 while ((rtn=::select(socket+1, NULL, write_set, except_set, timeout_ptr)) ==-1 && errno == EINTR);
349 if (rtn > 0 && (!FD_ISSET(socket,write_set)) && FD_ISSET(socket, except_set))
351 // if we are selected but cannot write and have an exception
352 // we have serious trouble...
353 EXCEPTIONSTREAM(error,t2n_transfer_error,"exception on socket; cannot write any more.");
357 EXCEPTIONSTREAM(error,t2n_transfer_error,"timeout on select() for write");
360 EXCEPTIONSTREAM(error,t2n_transfer_error,"cannot select() for write: " << strerror(errno));