/* * Copyright (c) 2001-2004 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 built upon the file: src/arch/rtxc/netif/sioslip.c * * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>  *//*  * This is an arch independent SLIP netif. The specific serial hooks must be * provided by another file. They are sio_open, sio_recv and sio_send */#include "netif/slipif.h"#include "lwip/opt.h"#include "lwip/def.h"#include "lwip/pbuf.h"#include "lwip/sys.h"#include "lwip/stats.h"#include "lwip/sio.h"#define SLIP_END     0300#define SLIP_ESC     0333#define SLIP_ESC_END 0334#define SLIP_ESC_ESC 0335#define MAX_SIZE     1500/** * Send a pbuf doing the necessary SLIP encapsulation * * Uses the serial layer's sio_send()  */err_tslipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr){  struct pbuf *q;  u16_t i;  u8_t c;  /* Send pbuf out on the serial I/O device. */  sio_send(SLIP_END, netif->state);  for (q = p; q != NULL; q = q->next) {    for (i = 0; i < q->len; i++) {      c = ((u8_t *)q->payload)[i];      switch (c) {      case SLIP_END:        sio_send(SLIP_ESC, netif->state);        sio_send(SLIP_ESC_END, netif->state);        break;      case SLIP_ESC:        sio_send(SLIP_ESC, netif->state);        sio_send(SLIP_ESC_ESC, netif->state);        break;      default:        sio_send(c, netif->state);        break;      }    }  }  sio_send(SLIP_END, netif->state);  return 0;}/** * Handle the incoming SLIP stream character by character * * Poll the serial layer by calling sio_recv() *  * @return The IP packet when SLIP_END is received  */static struct pbuf *slipif_input(struct netif *netif){  u8_t c;  struct pbuf *p, *q;  u16_t recved;  u16_t i;  q = p = NULL;  recved = i = 0;  c = 0;  while (1) {    c = sio_recv(netif->state);    switch (c) {    case SLIP_END:      if (recved > 0) {        /* Received whole packet. */        pbuf_realloc(q, recved);                LINK_STATS_INC(link.recv);                LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n"));        return q;      }      break;    case SLIP_ESC:      c = sio_recv(netif->state);      switch (c) {      case SLIP_ESC_END:        c = SLIP_END;        break;      case SLIP_ESC_ESC:        c = SLIP_ESC;        break;      }      /* FALLTHROUGH */    default:      if (p == NULL) {        LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));        p = pbuf_alloc(PBUF_LINK, PBUF_POOL_BUFSIZE, PBUF_POOL);        if (p == NULL) {          LINK_STATS_INC(link.drop);          LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));        }        if (q != NULL) {          pbuf_cat(q, p);        } else {          q = p;        }      }      if (p != NULL && recved < MAX_SIZE) {        ((u8_t *)p->payload)[i] = c;        recved++;        i++;        if (i >= p->len) {          i = 0;          if (p->next != NULL && p->next->len > 0)            p = p->next;          else            p = NULL;        }      }      break;    }  }  return NULL;}/** * The SLIP input thread. * * Feed the IP layer with incoming packets */static voidslipif_loop(void *nf){  struct pbuf *p;  struct netif *netif = (struct netif *)nf;  while (1) {    p = slipif_input(netif);    netif->input(p, netif);  }}/** * SLIP netif initialization * * Call the arch specific sio_open and remember * the opened device in the state field of the netif. */err_tslipif_init(struct netif *netif){  LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num));  netif->name[0] = 's';  netif->name[1] = 'l';  netif->output = slipif_output;  netif->mtu = 1500;  netif->flags = NETIF_FLAG_POINTTOPOINT;  netif->state = sio_open(netif->num);  if (!netif->state)    return ERR_IF;  sys_thread_new(slipif_loop, netif, SLIPIF_THREAD_PRIO);  return ERR_OK;}