FreeRTOS/Common/ethernet/lwIP/netif/slipif.c

   1 /*
   2  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the Institute nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * This file is built upon the file: src/arch/rtxc/netif/sioslip.c
  30  *
  31  * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>
  32  */
  33
  34 /*
  35  * This is an arch independent SLIP netif. The specific serial hooks must be
  36  * provided by another file. They are sio_open, sio_recv and sio_send
  37  */
  38
  39 #include "netif/slipif.h"
  40 #include "lwip/opt.h"
  41 #include "lwip/def.h"
  42 #include "lwip/pbuf.h"
  43 #include "lwip/sys.h"
  44 #include "lwip/stats.h"
  45 #include "lwip/sio.h"
  46
  47 #define SLIP_END     0300
  48 #define SLIP_ESC     0333
  49 #define SLIP_ESC_END 0334
  50 #define SLIP_ESC_ESC 0335
  51
  52 #define MAX_SIZE     1500
  53
  54 /**
  55  * Send a pbuf doing the necessary SLIP encapsulation
  56  *
  57  * Uses the serial layer's sio_send()
  58  */
  59 err_t
  60 slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
  61 {
  62   struct pbuf *q;
  63   u16_t i;
  64   u8_t c;
  65
  66   /* Send pbuf out on the serial I/O device. */
  67   sio_send(SLIP_END, netif->state);
  68
  69   for (q = p; q != NULL; q = q->next) {
  70     for (i = 0; i < q->len; i++) {
  71       c = ((u8_t *)q->payload)[i];
  72       switch (c) {
  73       case SLIP_END:
  74         sio_send(SLIP_ESC, netif->state);
  75         sio_send(SLIP_ESC_END, netif->state);
  76         break;
  77       case SLIP_ESC:
  78         sio_send(SLIP_ESC, netif->state);
  79         sio_send(SLIP_ESC_ESC, netif->state);
  80         break;
  81       default:
  82         sio_send(c, netif->state);
  83         break;
  84       }
  85     }
  86   }
  87   sio_send(SLIP_END, netif->state);
  88   return 0;
  89 }
  90
  91 /**
  92  * Handle the incoming SLIP stream character by character
  93  *
  94  * Poll the serial layer by calling sio_recv()
  95  *
  96  * @return The IP packet when SLIP_END is received
  97  */
  98 static struct pbuf *
  99 slipif_input(struct netif *netif)
 100 {
 101   u8_t c;
 102   struct pbuf *p, *q;
 103   u16_t recved;
 104   u16_t i;
 105
 106   q = p = NULL;
 107   recved = i = 0;
 108   c = 0;
 109
 110   while (1) {
 111     c = sio_recv(netif->state);
 112     switch (c) {
 113     case SLIP_END:
 114       if (recved > 0) {
 115         /* Received whole packet. */
 116         pbuf_realloc(q, recved);
 117
 118         LINK_STATS_INC(link.recv);
 119
 120         LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n"));
 121         return q;
 122       }
 123       break;
 124
 125     case SLIP_ESC:
 126       c = sio_recv(netif->state);
 127       switch (c) {
 128       case SLIP_ESC_END:
 129         c = SLIP_END;
 130         break;
 131       case SLIP_ESC_ESC:
 132         c = SLIP_ESC;
 133         break;
 134       }
 135       /* FALLTHROUGH */
 136
 137     default:
 138       if (p == NULL) {
 139         LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
 140         p = pbuf_alloc(PBUF_LINK, PBUF_POOL_BUFSIZE, PBUF_POOL);
 141
 142         if (p == NULL) {
 143           LINK_STATS_INC(link.drop);
 144           LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));
 145         }
 146
 147         if (q != NULL) {
 148           pbuf_cat(q, p);
 149         } else {
 150           q = p;
 151         }
 152       }
 153       if (p != NULL && recved < MAX_SIZE) {
 154         ((u8_t *)p->payload)[i] = c;
 155         recved++;
 156         i++;
 157         if (i >= p->len) {
 158           i = 0;
 159           if (p->next != NULL && p->next->len > 0)
 160             p = p->next;
 161           else
 162             p = NULL;
 163         }
 164       }
 165       break;
 166     }
 167
 168   }
 169   return NULL;
 170 }
 171
 172 /**
 173  * The SLIP input thread.
 174  *
 175  * Feed the IP layer with incoming packets
 176  */
 177 static void
 178 slipif_loop(void *nf)
 179 {
 180   struct pbuf *p;
 181   struct netif *netif = (struct netif *)nf;
 182
 183   while (1) {
 184     p = slipif_input(netif);
 185     netif->input(p, netif);
 186   }
 187 }
 188
 189 /**
 190  * SLIP netif initialization
 191  *
 192  * Call the arch specific sio_open and remember
 193  * the opened device in the state field of the netif.
 194  */
 195 err_t
 196 slipif_init(struct netif *netif)
 197 {
 198
 199   LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num));
 200
 201   netif->name[0] = 's';
 202   netif->name[1] = 'l';
 203   netif->output = slipif_output;
 204   netif->mtu = 1500;
 205   netif->flags = NETIF_FLAG_POINTTOPOINT;
 206
 207   netif->state = sio_open(netif->num);
 208   if (!netif->state)
 209     return ERR_IF;
 210
 211   sys_thread_new(slipif_loop, netif, SLIPIF_THREAD_PRIO);
 212   return ERR_OK;
 213 }