psock.h

00001 /*
00002  * Copyright (c) 2004, Swedish Institute of Computer Science.
00003  * All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the Institute nor the names of its contributors
00014  *    may be used to endorse or promote products derived from this software
00015  *    without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00027  * SUCH DAMAGE.
00028  *
00029  * This file is part of the uIP TCP/IP stack
00030  *
00031  * Author: Adam Dunkels <adam@sics.se>
00032  *
00033  * $Id: psock.h,v 1.3 2006/06/12 08:00:30 adam Exp $
00034  */
00035 
00036 /** @addtogroup EMAC_uIP
00037  * @{
00038  */
00039 
00040 /**
00041  * \defgroup psock Protosockets library
00042  * @{
00043  *
00044  * The protosocket library provides an interface to the uIP stack that is
00045  * similar to the traditional BSD socket interface. Unlike programs
00046  * written for the ordinary uIP event-driven interface, programs
00047  * written with the protosocket library are executed in a sequential
00048  * fashion and does not have to be implemented as explicit state
00049  * machines.
00050  *
00051  * Protosockets only work with TCP connections.
00052  *
00053  * The protosocket library uses \ref pt protothreads to provide
00054  * sequential control flow. This makes the protosockets lightweight in
00055  * terms of memory, but also means that protosockets inherits the
00056  * functional limitations of protothreads. Each protosocket lives only
00057  * within a single function. Automatic variables (stack variables) are
00058  * not retained across a protosocket library function call.
00059  *
00060  * \note Because the protosocket library uses protothreads, local
00061  * variables will not always be saved across a call to a protosocket
00062  * library function. It is therefore advised that local variables are
00063  * used with extreme care.
00064  *
00065  * The protosocket library provides functions for sending data without
00066  * having to deal with retransmissions and acknowledgements, as well
00067  * as functions for reading data without having to deal with data
00068  * being split across more than one TCP segment.
00069  *
00070  * Because each protosocket runs as a protothread, the protosocket has to be
00071  * started with a call to PSOCK_BEGIN() at the start of the function
00072  * in which the protosocket is used. Similarly, the protosocket protothread can
00073  * be terminated by a call to PSOCK_EXIT().
00074  *
00075  */
00076 
00077 /**
00078  * \file
00079  * Protosocket library header file
00080  * \author
00081  * Adam Dunkels <adam@sics.se>
00082  *
00083  */
00084 
00085 #ifndef __PSOCK_H__
00086 #define __PSOCK_H__
00087 
00088 #include "uipopt.h"
00089 #include "pt.h"
00090 
00091  /*
00092  * The structure that holds the state of a buffer.
00093  *
00094  * This structure holds the state of a uIP buffer. The structure has
00095  * no user-visible elements, but is used through the functions
00096  * provided by the library.
00097  *
00098  */
00099 struct psock_buf {
00100   u8_t *ptr;
00101   unsigned short left;
00102 };
00103 
00104 /**
00105  * The representation of a protosocket.
00106  *
00107  * The protosocket structrure is an opaque structure with no user-visible
00108  * elements.
00109  */
00110 struct psock {
00111   struct pt pt, psockpt; /* Protothreads - one that's using the psock
00112                 functions, and one that runs inside the
00113                 psock functions. */
00114   const u8_t *sendptr;   /* Pointer to the next data to be sent. */
00115   u8_t *readptr;         /* Pointer to the next data to be read. */
00116 
00117   char *bufptr;          /* Pointer to the buffer used for buffering
00118                 incoming data. */
00119 
00120   u16_t sendlen;         /* The number of bytes left to be sent. */
00121   u16_t readlen;         /* The number of bytes left to be read. */
00122 
00123   struct psock_buf buf;  /* The structure holding the state of the
00124                 input buffer. */
00125   unsigned int bufsize;  /* The size of the input buffer. */
00126 
00127   unsigned char state;   /* The state of the protosocket. */
00128 };
00129 
00130 void psock_init(struct psock *psock, char *buffer, unsigned int buffersize);
00131 /**
00132  * Initialize a protosocket.
00133  *
00134  * This macro initializes a protosocket and must be called before the
00135  * protosocket is used. The initialization also specifies the input buffer
00136  * for the protosocket.
00137  *
00138  * \param psock (struct psock *) A pointer to the protosocket to be
00139  * initialized
00140  *
00141  * \param buffer (char *) A pointer to the input buffer for the
00142  * protosocket.
00143  *
00144  * \param buffersize (unsigned int) The size of the input buffer.
00145  *
00146  * \hideinitializer
00147  */
00148 #define PSOCK_INIT(psock, buffer, buffersize) \
00149   psock_init(psock, buffer, buffersize)
00150 
00151 /**
00152  * Start the protosocket protothread in a function.
00153  *
00154  * This macro starts the protothread associated with the protosocket and
00155  * must come before other protosocket calls in the function it is used.
00156  *
00157  * \param psock (struct psock *) A pointer to the protosocket to be
00158  * started.
00159  *
00160  * \hideinitializer
00161  */
00162 #define PSOCK_BEGIN(psock) PT_BEGIN(&((psock)->pt))
00163 
00164 PT_THREAD(psock_send(struct psock *psock, const char *buf, unsigned int len));
00165 /**
00166  * Send data.
00167  *
00168  * This macro sends data over a protosocket. The protosocket protothread blocks
00169  * until all data has been sent and is known to have been received by
00170  * the remote end of the TCP connection.
00171  *
00172  * \param psock (struct psock *) A pointer to the protosocket over which
00173  * data is to be sent.
00174  *
00175  * \param data (char *) A pointer to the data that is to be sent.
00176  *
00177  * \param datalen (unsigned int) The length of the data that is to be
00178  * sent.
00179  *
00180  * \hideinitializer
00181  */
00182 #define PSOCK_SEND(psock, data, datalen)        \
00183     PT_WAIT_THREAD(&((psock)->pt), psock_send(psock, data, datalen))
00184 
00185 /**
00186  * \brief      Send a null-terminated string.
00187  * \param psock Pointer to the protosocket.
00188  * \param str  The string to be sent.
00189  *
00190  *             This function sends a null-terminated string over the
00191  *             protosocket.
00192  *
00193  * \hideinitializer
00194  */
00195 #define PSOCK_SEND_STR(psock, str)              \
00196     PT_WAIT_THREAD(&((psock)->pt), psock_send(psock, str, strlen(str)))
00197 
00198 PT_THREAD(psock_generator_send(struct psock *psock,
00199                 unsigned short (*f)(void *), void *arg));
00200 
00201 /**
00202  * \brief      Generate data with a function and send it
00203  * \param psock Pointer to the protosocket.
00204  * \param generator Pointer to the generator function
00205  * \param arg   Argument to the generator function
00206  *
00207  *             This function generates data and sends it over the
00208  *             protosocket. This can be used to dynamically generate
00209  *             data for a transmission, instead of generating the data
00210  *             in a buffer beforehand. This function reduces the need for
00211  *             buffer memory. The generator function is implemented by
00212  *             the application, and a pointer to the function is given
00213  *             as an argument with the call to PSOCK_GENERATOR_SEND().
00214  *
00215  *             The generator function should place the generated data
00216  *             directly in the uip_appdata buffer, and return the
00217  *             length of the generated data. The generator function is
00218  *             called by the protosocket layer when the data first is
00219  *             sent, and once for every retransmission that is needed.
00220  *
00221  * \hideinitializer
00222  */
00223 #define PSOCK_GENERATOR_SEND(psock, generator, arg)     \
00224     PT_WAIT_THREAD(&((psock)->pt),                  \
00225            psock_generator_send(psock, generator, arg))
00226 
00227 
00228 /**
00229  * Close a protosocket.
00230  *
00231  * This macro closes a protosocket and can only be called from within the
00232  * protothread in which the protosocket lives.
00233  *
00234  * \param psock (struct psock *) A pointer to the protosocket that is to
00235  * be closed.
00236  *
00237  * \hideinitializer
00238  */
00239 #define PSOCK_CLOSE(psock) uip_close()
00240 
00241 PT_THREAD(psock_readbuf(struct psock *psock));
00242 /**
00243  * Read data until the buffer is full.
00244  *
00245  * This macro will block waiting for data and read the data into the
00246  * input buffer specified with the call to PSOCK_INIT(). Data is read
00247  * until the buffer is full..
00248  *
00249  * \param psock (struct psock *) A pointer to the protosocket from which
00250  * data should be read.
00251  *
00252  * \hideinitializer
00253  */
00254 #define PSOCK_READBUF(psock)                \
00255   PT_WAIT_THREAD(&((psock)->pt), psock_readbuf(psock))
00256 
00257 PT_THREAD(psock_readto(struct psock *psock, unsigned char c));
00258 /**
00259  * Read data up to a specified character.
00260  *
00261  * This macro will block waiting for data and read the data into the
00262  * input buffer specified with the call to PSOCK_INIT(). Data is only
00263  * read until the specifieed character appears in the data stream.
00264  *
00265  * \param psock (struct psock *) A pointer to the protosocket from which
00266  * data should be read.
00267  *
00268  * \param c (char) The character at which to stop reading.
00269  *
00270  * \hideinitializer
00271  */
00272 #define PSOCK_READTO(psock, c)              \
00273   PT_WAIT_THREAD(&((psock)->pt), psock_readto(psock, c))
00274 
00275 /**
00276  * The length of the data that was previously read.
00277  *
00278  * This macro returns the length of the data that was previously read
00279  * using PSOCK_READTO() or PSOCK_READ().
00280  *
00281  * \param psock (struct psock *) A pointer to the protosocket holding the data.
00282  *
00283  * \hideinitializer
00284  */
00285 #define PSOCK_DATALEN(psock) psock_datalen(psock)
00286 
00287 u16_t psock_datalen(struct psock *psock);
00288 
00289 /**
00290  * Exit the protosocket's protothread.
00291  *
00292  * This macro terminates the protothread of the protosocket and should
00293  * almost always be used in conjunction with PSOCK_CLOSE().
00294  *
00295  * \sa PSOCK_CLOSE_EXIT()
00296  *
00297  * \param psock (struct psock *) A pointer to the protosocket.
00298  *
00299  * \hideinitializer
00300  */
00301 #define PSOCK_EXIT(psock) PT_EXIT(&((psock)->pt))
00302 
00303 /**
00304  * Close a protosocket and exit the protosocket's protothread.
00305  *
00306  * This macro closes a protosocket and exits the protosocket's protothread.
00307  *
00308  * \param psock (struct psock *) A pointer to the protosocket.
00309  *
00310  * \hideinitializer
00311  */
00312 #define PSOCK_CLOSE_EXIT(psock)     \
00313   do {                      \
00314     PSOCK_CLOSE(psock);         \
00315     PSOCK_EXIT(psock);          \
00316   } while(0)
00317 
00318 /**
00319  * Declare the end of a protosocket's protothread.
00320  *
00321  * This macro is used for declaring that the protosocket's protothread
00322  * ends. It must always be used together with a matching PSOCK_BEGIN()
00323  * macro.
00324  *
00325  * \param psock (struct psock *) A pointer to the protosocket.
00326  *
00327  * \hideinitializer
00328  */
00329 #define PSOCK_END(psock) PT_END(&((psock)->pt))
00330 
00331 char psock_newdata(struct psock *s);
00332 
00333 /**
00334  * Check if new data has arrived on a protosocket.
00335  *
00336  * This macro is used in conjunction with the PSOCK_WAIT_UNTIL()
00337  * macro to check if data has arrived on a protosocket.
00338  *
00339  * \param psock (struct psock *) A pointer to the protosocket.
00340  *
00341  * \hideinitializer
00342  */
00343 #define PSOCK_NEWDATA(psock) psock_newdata(psock)
00344 
00345 /**
00346  * Wait until a condition is true.
00347  *
00348  * This macro blocks the protothread until the specified condition is
00349  * true. The macro PSOCK_NEWDATA() can be used to check if new data
00350  * arrives when the protosocket is waiting.
00351  *
00352  * Typically, this macro is used as follows:
00353  *
00354  \code
00355  PT_THREAD(thread(struct psock *s, struct timer *t))
00356  {
00357    PSOCK_BEGIN(s);
00358 
00359    PSOCK_WAIT_UNTIL(s, PSOCK_NEWADATA(s) || timer_expired(t));
00360 
00361    if(PSOCK_NEWDATA(s)) {
00362      PSOCK_READTO(s, '\n');
00363    } else {
00364      handle_timed_out(s);
00365    }
00366 
00367    PSOCK_END(s);
00368  }
00369  \endcode
00370  *
00371  * \param psock (struct psock *) A pointer to the protosocket.
00372  * \param condition The condition to wait for.
00373  *
00374  * \hideinitializer
00375  */
00376 #define PSOCK_WAIT_UNTIL(psock, condition)    \
00377   PT_WAIT_UNTIL(&((psock)->pt), (condition));
00378 
00379 #define PSOCK_WAIT_THREAD(psock, condition)   \
00380   PT_WAIT_THREAD(&((psock)->pt), (condition))
00381 
00382 #endif /* __PSOCK_H__ */
00383 
00384 /** @} */