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 , socket_type(_socket_type)
58 /// set options like fast reuse and keepalive every socket should have
59 void socket_handler::set_socket_options(int sock)
63 /* fast reuse enable */
64 if (setsockopt(sock,SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i)) < 0)
65 EXCEPTIONSTREAM(error,t2n_communication_error,"error setting socket option: " << strerror(errno));
67 /* keepalive enable */
68 if (setsockopt(sock,SOL_SOCKET, SO_KEEPALIVE, &i, sizeof(i)) < 0)
69 EXCEPTIONSTREAM(error,t2n_communication_error,"error setting socket option: " << strerror(errno));
73 fdflags=fcntl(sock,F_GETFD, 0);
75 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
77 fdflags |= FD_CLOEXEC;
78 if (fcntl(sock,F_SETFD,fdflags) < 0)
79 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
81 /* non-blocking mode */
83 flflags=fcntl(sock,F_GETFL,0);
85 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
87 flflags |= O_NONBLOCK;
88 if (fcntl(sock,F_SETFL,flflags) < 0)
89 EXCEPTIONSTREAM(error,t2n_communication_error,"fcntl error on socket: " << strerror(errno));
92 /// close the underlying socket connection. Don't call directly, use the version provided
93 /// by the connection class you are using.
94 void socket_handler::close()
97 shutdown(sock,SHUT_RDWR);
101 /// is the underlying socket connection still open?
102 bool socket_handler::is_closed()
104 int r=fcntl(sock,F_GETFL);
106 return !(r & O_ACCMODE);
111 * @brief set a new size for the receive buffer.
112 * @param new_recv_buffer_size the new size for the receive buffer.
114 * The receive buffer determines the amount of data which is tried to read at once
115 * from the underlying socket.
117 * The value is normalized to be at least 512 bytes and at max 32K bytes.
119 void socket_handler::set_recv_buffer_size(unsigned int new_recv_buffer_size)
121 recv_buffer_size= std::max( 512u, std::min( 32u * 1024u, new_recv_buffer_size ));
126 * @brief set new size for the data chunks when writeing.
127 * @param new_write_block_size the new chunk size.
129 * The write block size determines the amound of data which is tried to write
130 * to the socket when data needs to be sended.
131 * Since writeing data is done in a loop, this does not limit the amunt of data which can
134 * The value is normalized to be at least 512 bytes and at max 32K bytes.
136 void socket_handler::set_write_block_size(unsigned int new_write_block_size)
138 write_block_size= std::max( 512u, std::min( 32u * 1024u, new_write_block_size ));
142 /** @brief check if new data is waiting on the raw socket
143 @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
147 bool socket_handler::data_waiting(long long usec_timeout,long long* usec_timeout_remaining)
150 fd_set active_fd_set;
151 FD_ZERO (&active_fd_set);
152 FD_SET (sock, &active_fd_set);
156 struct timeval *timeout_ptr;
158 if (usec_timeout == -1)
164 // convert timeout from long long usec to int sec + int usec
165 tval.tv_sec = usec_timeout / 1000000;
166 tval.tv_usec = usec_timeout % 1000000;
169 int ret=select (FD_SETSIZE, &active_fd_set, NULL, NULL, timeout_ptr);
171 // return the timeout we did not use
172 // todo: this is linux specific according to man 2 select
173 if (usec_timeout > 0 && usec_timeout_remaining != NULL)
174 *usec_timeout_remaining=(tval.tv_sec*1000000)+tval.tv_usec;
182 /** @brief read data from the raw socket and copy it into the provided buffer
183 @param buffer the buffer where to append the new data
184 @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
188 bool socket_handler::fill_buffer(std::string& buffer, long long usec_timeout, long long *timeout_remaining)
190 // fast path for timeout==0
191 if (usec_timeout==0 || data_waiting(usec_timeout,timeout_remaining))
192 return fill_buffer(buffer);
197 /** @brief read data from the raw socket and copy it into the provided buffer. Returns
198 instantly if no data is waiting.
199 @param buffer the buffer where to append the new data
201 bool socket_handler::fill_buffer(std::string& buffer)
203 bool try_again=false;
205 char socket_buffer[recv_buffer_size];
207 int nbytes = read (sock, socket_buffer, recv_buffer_size);
211 return false; // no data was waiting
212 else if (errno == EINTR)
214 // interrupted, try again
215 LOGSTREAM(debug,"EINTR received on read(), trying again");
220 LOGSTREAM(error,"error reading from socket : " << strerror(errno));
227 if (nbytes == 0 && !try_again)
229 LOGSTREAM(debug,"0 bytes received on read(), closing connection");
234 // Data read -> store it
237 buffer.append(socket_buffer,nbytes);
238 LOGSTREAM(debug,nbytes << " bytes read");
241 // more data waiting -> recurse
251 /// writes raw data to the socket. Don't use directly, use the write() function provided by the
252 /// connection because it encapsulates the data.
253 void socket_handler::socket_write(const std::string& data)
256 while (offset < data.size())
258 unsigned int write_size=write_block_size;
260 if (offset+write_size > data.size())
261 write_size = data.size()-offset;
264 while ((rtn=::write(sock, data.data()+offset, write_size)) &&
265 rtn == -1 && (errno == EAGAIN || errno == EINTR))
268 fd_set except_set[1];
271 FD_SET(sock, write_set);
272 FD_SET(sock, except_set);
273 // let's wait for the socket to become writable again...
274 //TODO: use a timeout here?
275 int n= ::select(sock+1, NULL, write_set, except_set, NULL);
276 if (n==1 && ! FD_ISSET(sock,write_set) && FD_ISSET(sock, except_set))
278 // if we are selected but cannot write and have an exception
279 // we have serious trouble...
280 LOGSTREAM(error,"exception on socket; cannot write any more.");
284 LOGSTREAM(debug,"resuming write() call after EAGAIN or EINTR");
289 LOGSTREAM(error,"write() returned " << strerror(errno));
293 else if (rtn != write_size)
295 LOGSTREAM(debug,"write() wrote " << rtn << " bytes, should have been "
296 << write_size << " (complete: " << data.size() << ")");
301 offset += write_size;
304 LOGSTREAM(debug,"wrote " << data.size() << " bytes");
307 } // eo socket_handler::socket_write(const std::string&)