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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [uIP_Demo_IAR_ARM7/] [uip/] [slipdev.c] - Rev 620
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/** * \addtogroup uip * @{ */ /** * \defgroup slip Serial Line IP (SLIP) protocol * @{ * * The SLIP protocol is a very simple way to transmit IP packets over * a serial line. It does not provide any framing or error control, * and is therefore not very widely used today. * * This SLIP implementation requires two functions for accessing the * serial device: slipdev_char_poll() and slipdev_char_put(). These * must be implemented specifically for the system on which the SLIP * protocol is to be run. */ /** * \file * SLIP protocol implementation * \author Adam Dunkels <adam@dunkels.com> */ /* * Copyright (c) 2001, Adam Dunkels. * 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. The name of the author may not be used to endorse or promote * products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 uIP TCP/IP stack. * * $Id: slipdev.c 2 2011-07-17 20:13:17Z filepang@gmail.com $ * */ /* * This is a generic implementation of the SLIP protocol over an RS232 * (serial) device. * * Huge thanks to Ullrich von Bassewitz <uz@cc65.org> of cc65 fame for * and endless supply of bugfixes, insightsful comments and * suggestions, and improvements to this code! */ #include "uip.h" #define SLIP_END 0300 #define SLIP_ESC 0333 #define SLIP_ESC_END 0334 #define SLIP_ESC_ESC 0335 static u8_t slip_buf[UIP_BUFSIZE]; static u16_t len, tmplen; static u8_t lastc; /*-----------------------------------------------------------------------------------*/ /** * Send the packet in the uip_buf and uip_appdata buffers using the * SLIP protocol. * * The first 40 bytes of the packet (the IP and TCP headers) are read * from the uip_buf buffer, and the following bytes (the application * data) are read from the uip_appdata buffer. * */ /*-----------------------------------------------------------------------------------*/ void slipdev_send(void) { u16_t i; u8_t *ptr; u8_t c; slipdev_char_put(SLIP_END); ptr = uip_buf; for(i = 0; i < uip_len; ++i) { if(i == 40) { ptr = (u8_t *)uip_appdata; } c = *ptr++; switch(c) { case SLIP_END: slipdev_char_put(SLIP_ESC); slipdev_char_put(SLIP_ESC_END); break; case SLIP_ESC: slipdev_char_put(SLIP_ESC); slipdev_char_put(SLIP_ESC_ESC); break; default: slipdev_char_put(c); break; } } slipdev_char_put(SLIP_END); } /*-----------------------------------------------------------------------------------*/ /** * Poll the SLIP device for an available packet. * * This function will poll the SLIP device to see if a packet is * available. It uses a buffer in which all avaliable bytes from the * RS232 interface are read into. When a full packet has been read * into the buffer, the packet is copied into the uip_buf buffer and * the length of the packet is returned. * * \return The length of the packet placed in the uip_buf buffer, or * zero if no packet is available. */ /*-----------------------------------------------------------------------------------*/ u16_t slipdev_poll(void) { u8_t c; while(slipdev_char_poll(c)) { switch(c) { case SLIP_ESC: lastc = c; break; case SLIP_END: lastc = c; /* End marker found, we copy our input buffer to the uip_buf buffer and return the size of the packet we copied. */ memcpy(uip_buf, slip_buf, len); tmplen = len; len = 0; return tmplen; default: if(lastc == SLIP_ESC) { lastc = c; /* Previous read byte was an escape byte, so this byte will be interpreted differently from others. */ switch(c) { case SLIP_ESC_END: c = SLIP_END; break; case SLIP_ESC_ESC: c = SLIP_ESC; break; } } else { lastc = c; } slip_buf[len] = c; ++len; if(len > UIP_BUFSIZE) { len = 0; } break; } } return 0; } /*-----------------------------------------------------------------------------------*/ /** * Initialize the SLIP module. * * This function does not initialize the underlying RS232 device, but * only the SLIP part. */ /*-----------------------------------------------------------------------------------*/ void slipdev_init(void) { lastc = len = 0; } /*-----------------------------------------------------------------------------------*/ /** @} */ /** @} */
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