contiki/core/net/ip/psock.h

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/*
* Copyright (c) 2004, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
/**
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* \addtogroup uip
* @{
*/
/**
* \defgroup psock Protosockets library
* @{
*
* The protosocket library provides an interface to the uIP stack that is
* similar to the traditional BSD socket interface. Unlike programs
* written for the ordinary uIP event-driven interface, programs
* written with the protosocket library are executed in a sequential
* fashion and does not have to be implemented as explicit state
* machines.
*
* Protosockets only work with TCP connections.
*
* The protosocket library uses \ref pt protothreads to provide
* sequential control flow. This makes the protosockets lightweight in
* terms of memory, but also means that protosockets inherits the
* functional limitations of protothreads. Each protosocket lives only
* within a single function block. Automatic variables (stack
* variables) are not necessarily retained across a protosocket
* library function call.
*
* \note Because the protosocket library uses protothreads, local variables
* will not always be saved across a call to a protosocket library
* function. It is therefore advised that local variables are used
* with extreme care.
*
* The protosocket library provides functions for sending data without
* having to deal with retransmissions and acknowledgements, as well
* as functions for reading data without having to deal with data
* being split across more than one TCP segment.
*
* Because each protosocket runs as a protothread, the protosocket has to be
* started with a call to PSOCK_BEGIN() at the start of the function
* in which the protosocket is used. Similarly, the protosocket protothread can
* be terminated by a call to PSOCK_EXIT().
*
*/
/**
* \file
* Protosocket library header file
* \author
* Adam Dunkels <adam@sics.se>
*
*/
#ifndef PSOCK_H_
#define PSOCK_H_
#include "contiki.h"
#include "contiki-lib.h"
#include "contiki-net.h"
/*
* The structure that holds the state of a buffer.
*
* This structure holds the state of a uIP buffer. The structure has
* no user-visible elements, but is used through the functions
* provided by the library.
*
*/
struct psock_buf {
uint8_t *ptr;
unsigned short left;
};
/**
* The representation of a protosocket.
*
* The protosocket structrure is an opaque structure with no user-visible
* elements.
*/
struct psock {
struct pt pt, psockpt; /* Protothreads - one that's using the psock
functions, and one that runs inside the
psock functions. */
const uint8_t *sendptr; /* Pointer to the next data to be sent. */
uint8_t *readptr; /* Pointer to the next data to be read. */
uint8_t *bufptr; /* Pointer to the buffer used for buffering
incoming data. */
uint16_t sendlen; /* The number of bytes left to be sent. */
uint16_t readlen; /* The number of bytes left to be read. */
struct psock_buf buf; /* The structure holding the state of the
input buffer. */
unsigned int bufsize; /* The size of the input buffer. */
unsigned char state; /* The state of the protosocket. */
};
void psock_init(struct psock *psock, uint8_t *buffer, unsigned int buffersize);
/**
* Initialize a protosocket.
*
* This macro initializes a protosocket and must be called before the
* protosocket is used. The initialization also specifies the input buffer
* for the protosocket.
*
* \param psock (struct psock *) A pointer to the protosocket to be
* initialized
*
* \param buffer (uint8_t *) A pointer to the input buffer for the
* protosocket.
*
* \param buffersize (unsigned int) The size of the input buffer.
*
* \hideinitializer
*/
#define PSOCK_INIT(psock, buffer, buffersize) \
psock_init(psock, buffer, buffersize)
/**
* Start the protosocket protothread in a function.
*
* This macro starts the protothread associated with the protosocket and
* must come before other protosocket calls in the function it is used.
*
* \param psock (struct psock *) A pointer to the protosocket to be
* started.
*
* \hideinitializer
*/
#define PSOCK_BEGIN(psock) PT_BEGIN(&((psock)->pt))
PT_THREAD(psock_send(struct psock *psock, const uint8_t *buf, unsigned int len));
/**
* Send data.
*
* This macro sends data over a protosocket. The protosocket protothread blocks
* until all data has been sent and is known to have been received by
* the remote end of the TCP connection.
*
* \param psock (struct psock *) A pointer to the protosocket over which
* data is to be sent.
*
* \param data (uint8_t *) A pointer to the data that is to be sent.
*
* \param datalen (unsigned int) The length of the data that is to be
* sent.
*
* \hideinitializer
*/
#define PSOCK_SEND(psock, data, datalen) \
PT_WAIT_THREAD(&((psock)->pt), psock_send(psock, data, datalen))
/**
* \brief Send a null-terminated string.
* \param psock Pointer to the protosocket.
* \param str The string to be sent.
*
* This function sends a null-terminated string over the
* protosocket.
*
* \hideinitializer
*/
#define PSOCK_SEND_STR(psock, str) \
PT_WAIT_THREAD(&((psock)->pt), psock_send(psock, (uint8_t *)str, strlen(str)))
PT_THREAD(psock_generator_send(struct psock *psock,
unsigned short (*f)(void *), void *arg));
/**
* \brief Generate data with a function and send it
* \param psock Pointer to the protosocket.
* \param generator Pointer to the generator function
* \param arg Argument to the generator function
*
* This function generates data and sends it over the
* protosocket. This can be used to dynamically generate
* data for a transmission, instead of generating the data
* in a buffer beforehand. This function reduces the need for
* buffer memory. The generator function is implemented by
* the application, and a pointer to the function is given
* as an argument with the call to PSOCK_GENERATOR_SEND().
*
* The generator function should place the generated data
* directly in the uip_appdata buffer, and return the
* length of the generated data. The generator function is
* called by the protosocket layer when the data first is
* sent, and once for every retransmission that is needed.
*
* \hideinitializer
*/
#define PSOCK_GENERATOR_SEND(psock, generator, arg) \
PT_WAIT_THREAD(&((psock)->pt), \
psock_generator_send(psock, generator, arg))
/**
* Close a protosocket.
*
* This macro closes a protosocket and can only be called from within the
* protothread in which the protosocket lives.
*
* \param psock (struct psock *) A pointer to the protosocket that is to
* be closed.
*
* \hideinitializer
*/
#define PSOCK_CLOSE(psock) uip_close()
PT_THREAD(psock_readbuf_len(struct psock *psock, uint16_t len));
/**
* Read data until the buffer is full.
*
* This macro will block waiting for data and read the data into the
* input buffer specified with the call to PSOCK_INIT(). Data is read
* until the buffer is full..
*
* \param psock (struct psock *) A pointer to the protosocket from which
* data should be read.
*
* \hideinitializer
*/
#define PSOCK_READBUF(psock) \
PT_WAIT_THREAD(&((psock)->pt), psock_readbuf_len(psock, 1))
/**
* Read data until at least len bytes have been read.
*
* This macro will block waiting for data and read the data into the
* input buffer specified with the call to PSOCK_INIT(). Data is read
* until the buffer is full or len bytes have been read.
*
* \param psock (struct psock *) A pointer to the protosocket from which
* data should be read.
* \param len (uint16_t) The minimum number of bytes to read.
*
* \hideinitializer
*/
#define PSOCK_READBUF_LEN(psock, len) \
PT_WAIT_THREAD(&((psock)->pt), psock_readbuf_len(psock, len))
PT_THREAD(psock_readto(struct psock *psock, unsigned char c));
/**
* Read data up to a specified character.
*
* This macro will block waiting for data and read the data into the
* input buffer specified with the call to PSOCK_INIT(). Data is only
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* read until the specified character appears in the data stream.
*
* \param psock (struct psock *) A pointer to the protosocket from which
* data should be read.
*
* \param c (char) The character at which to stop reading.
*
* \hideinitializer
*/
#define PSOCK_READTO(psock, c) \
PT_WAIT_THREAD(&((psock)->pt), psock_readto(psock, c))
/**
* The length of the data that was previously read.
*
* This macro returns the length of the data that was previously read
* using PSOCK_READTO() or PSOCK_READ().
*
* \param psock (struct psock *) A pointer to the protosocket holding the data.
*
* \hideinitializer
*/
#define PSOCK_DATALEN(psock) psock_datalen(psock)
uint16_t psock_datalen(struct psock *psock);
/**
* Exit the protosocket's protothread.
*
* This macro terminates the protothread of the protosocket and should
* almost always be used in conjunction with PSOCK_CLOSE().
*
* \sa PSOCK_CLOSE_EXIT()
*
* \param psock (struct psock *) A pointer to the protosocket.
*
* \hideinitializer
*/
#define PSOCK_EXIT(psock) PT_EXIT(&((psock)->pt))
/**
* Close a protosocket and exit the protosocket's protothread.
*
* This macro closes a protosocket and exits the protosocket's protothread.
*
* \param psock (struct psock *) A pointer to the protosocket.
*
* \hideinitializer
*/
#define PSOCK_CLOSE_EXIT(psock) \
do { \
PSOCK_CLOSE(psock); \
PSOCK_EXIT(psock); \
} while(0)
/**
* Declare the end of a protosocket's protothread.
*
* This macro is used for declaring that the protosocket's protothread
* ends. It must always be used together with a matching PSOCK_BEGIN()
* macro.
*
* \param psock (struct psock *) A pointer to the protosocket.
*
* \hideinitializer
*/
#define PSOCK_END(psock) PT_END(&((psock)->pt))
char psock_newdata(struct psock *s);
/**
* Check if new data has arrived on a protosocket.
*
* This macro is used in conjunction with the PSOCK_WAIT_UNTIL()
* macro to check if data has arrived on a protosocket.
*
* \param psock (struct psock *) A pointer to the protosocket.
*
* \hideinitializer
*/
#define PSOCK_NEWDATA(psock) psock_newdata(psock)
/**
* Wait until a condition is true.
*
* This macro blocks the protothread until the specified condition is
* true. The macro PSOCK_NEWDATA() can be used to check if new data
* arrives when the protosocket is waiting.
*
* Typically, this macro is used as follows:
*
\code
PT_THREAD(thread(struct psock *s, struct timer *t))
{
PSOCK_BEGIN(s);
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PSOCK_WAIT_UNTIL(s, PSOCK_NEWDATA(s) || timer_expired(t));
if(PSOCK_NEWDATA(s)) {
PSOCK_READTO(s, '\n');
} else {
handle_timed_out(s);
}
PSOCK_END(s);
}
\endcode
*
* \param psock (struct psock *) A pointer to the protosocket.
* \param condition The condition to wait for.
*
* \hideinitializer
*/
#define PSOCK_WAIT_UNTIL(psock, condition) \
PT_WAIT_UNTIL(&((psock)->pt), (condition));
#define PSOCK_WAIT_THREAD(psock, condition) \
PT_WAIT_THREAD(&((psock)->pt), (condition))
#endif /* PSOCK_H_ */
/** @} */
/** @} */