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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [Common/] [ethernet/] [lwIP_132/] [src/] [netif/] [slipif.c] - Blame information for rev 606

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1 606 jeremybenn
/**
2
 * @file
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 * SLIP Interface
4
 *
5
 */
6
 
7
/*
8
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
9
 * All rights reserved.
10
 *
11
 * Redistribution and use in source and binary forms, with or without
12
 * modification, are permitted provided that the following conditions
13
 * are met:
14
 * 1. Redistributions of source code must retain the above copyright
15
 *    notice, this list of conditions and the following disclaimer.
16
 * 2. Redistributions in binary form must reproduce the above copyright
17
 *    notice, this list of conditions and the following disclaimer in the
18
 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the Institute nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
23
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 *
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 * This file is built upon the file: src/arch/rtxc/netif/sioslip.c
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 *
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 * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>
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 */
39
 
40
/*
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 * This is an arch independent SLIP netif. The specific serial hooks must be
42
 * provided by another file. They are sio_open, sio_read/sio_tryread and sio_send
43
 */
44
 
45
#include "netif/slipif.h"
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#include "lwip/opt.h"
47
 
48
#if LWIP_HAVE_SLIPIF
49
 
50
#include "lwip/def.h"
51
#include "lwip/pbuf.h"
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#include "lwip/sys.h"
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#include "lwip/stats.h"
54
#include "lwip/snmp.h"
55
#include "lwip/sio.h"
56
 
57
#define SLIP_BLOCK     1
58
#define SLIP_DONTBLOCK 0
59
 
60
#define SLIP_END     0300 /* 0xC0 */
61
#define SLIP_ESC     0333 /* 0xDB */
62
#define SLIP_ESC_END 0334 /* 0xDC */
63
#define SLIP_ESC_ESC 0335 /* 0xDD */
64
 
65
#define SLIP_MAX_SIZE 1500
66
 
67
enum slipif_recv_state {
68
    SLIP_RECV_NORMAL,
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    SLIP_RECV_ESCAPE,
70
};
71
 
72
struct slipif_priv {
73
  sio_fd_t sd;
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  /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
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  struct pbuf *p, *q;
76
  enum slipif_recv_state state;
77
  u16_t i, recved;
78
};
79
 
80
/**
81
 * Send a pbuf doing the necessary SLIP encapsulation
82
 *
83
 * Uses the serial layer's sio_send()
84
 *
85
 * @param netif the lwip network interface structure for this slipif
86
 * @param p the pbuf chaing packet to send
87
 * @param ipaddr the ip address to send the packet to (not used for slipif)
88
 * @return always returns ERR_OK since the serial layer does not provide return values
89
 */
90
err_t
91
slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
92
{
93
  struct slipif_priv *priv;
94
  struct pbuf *q;
95
  u16_t i;
96
  u8_t c;
97
 
98
  LWIP_ASSERT("netif != NULL", (netif != NULL));
99
  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
100
  LWIP_ASSERT("p != NULL", (p != NULL));
101
 
102
  LWIP_UNUSED_ARG(ipaddr);
103
 
104
  priv = netif->state;
105
 
106
  /* Send pbuf out on the serial I/O device. */
107
  sio_send(SLIP_END, priv->sd);
108
 
109
  for (q = p; q != NULL; q = q->next) {
110
    for (i = 0; i < q->len; i++) {
111
      c = ((u8_t *)q->payload)[i];
112
      switch (c) {
113
      case SLIP_END:
114
        sio_send(SLIP_ESC, priv->sd);
115
        sio_send(SLIP_ESC_END, priv->sd);
116
        break;
117
      case SLIP_ESC:
118
        sio_send(SLIP_ESC, priv->sd);
119
        sio_send(SLIP_ESC_ESC, priv->sd);
120
        break;
121
      default:
122
        sio_send(c, priv->sd);
123
        break;
124
      }
125
    }
126
  }
127
  sio_send(SLIP_END, priv->sd);
128
  return ERR_OK;
129
}
130
 
131
/**
132
 * Static function for easy use of blockig or non-blocking
133
 * sio_read
134
 *
135
 * @param fd serial device handle
136
 * @param data pointer to data buffer for receiving
137
 * @param len maximum length (in bytes) of data to receive
138
 * @param block if 1, call sio_read; if 0, call sio_tryread
139
 * @return return value of sio_read of sio_tryread
140
 */
141
static u32_t
142
slip_sio_read(sio_fd_t fd, u8_t* data, u32_t len, u8_t block)
143
{
144
  if (block) {
145
    return sio_read(fd, data, len);
146
  } else {
147
    return sio_tryread(fd, data, len);
148
  }
149
}
150
 
151
/**
152
 * Handle the incoming SLIP stream character by character
153
 *
154
 * Poll the serial layer by calling sio_read() or sio_tryread().
155
 *
156
 * @param netif the lwip network interface structure for this slipif
157
 * @param block if 1, block until data is received; if 0, return when all data
158
 *        from the buffer is received (multiple calls to this function will
159
 *        return a complete packet, NULL is returned before - used for polling)
160
 * @return The IP packet when SLIP_END is received
161
 */
162
static struct pbuf *
163
slipif_input(struct netif *netif, u8_t block)
164
{
165
  struct slipif_priv *priv;
166
  u8_t c;
167
  struct pbuf *t;
168
 
169
  LWIP_ASSERT("netif != NULL", (netif != NULL));
170
  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
171
 
172
  priv = netif->state;
173
 
174
  while (slip_sio_read(priv->sd, &c, 1, block) > 0) {
175
    switch (priv->state) {
176
    case SLIP_RECV_NORMAL:
177
      switch (c) {
178
      case SLIP_END:
179
        if (priv->recved > 0) {
180
          /* Received whole packet. */
181
          /* Trim the pbuf to the size of the received packet. */
182
          pbuf_realloc(priv->q, priv->recved);
183
 
184
          LINK_STATS_INC(link.recv);
185
 
186
          LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n"));
187
          t = priv->q;
188
          priv->p = priv->q = NULL;
189
          priv->i = priv->recved = 0;
190
          return t;
191
        }
192
        continue;
193
      case SLIP_ESC:
194
        priv->state = SLIP_RECV_ESCAPE;
195
        continue;
196
      }
197
      break;
198
    case SLIP_RECV_ESCAPE:
199
      switch (c) {
200
      case SLIP_ESC_END:
201
        c = SLIP_END;
202
        break;
203
      case SLIP_ESC_ESC:
204
        c = SLIP_ESC;
205
        break;
206
      }
207
      priv->state = SLIP_RECV_NORMAL;
208
      /* FALLTHROUGH */
209
    }
210
 
211
    /* byte received, packet not yet completely received */
212
    if (priv->p == NULL) {
213
      /* allocate a new pbuf */
214
      LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
215
      priv->p = pbuf_alloc(PBUF_LINK, (PBUF_POOL_BUFSIZE - PBUF_LINK_HLEN), PBUF_POOL);
216
 
217
      if (priv->p == NULL) {
218
        LINK_STATS_INC(link.drop);
219
        LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));
220
        /* don't process any further since we got no pbuf to receive to */
221
        break;
222
      }
223
 
224
      if (priv->q != NULL) {
225
        /* 'chain' the pbuf to the existing chain */
226
        pbuf_cat(priv->q, priv->p);
227
      } else {
228
        /* p is the first pbuf in the chain */
229
        priv->q = priv->p;
230
      }
231
    }
232
 
233
    /* this automatically drops bytes if > SLIP_MAX_SIZE */
234
    if ((priv->p != NULL) && (priv->recved <= SLIP_MAX_SIZE)) {
235
      ((u8_t *)priv->p->payload)[priv->i] = c;
236
      priv->recved++;
237
      priv->i++;
238
      if (priv->i >= priv->p->len) {
239
        /* on to the next pbuf */
240
        priv->i = 0;
241
        if (priv->p->next != NULL && priv->p->next->len > 0) {
242
          /* p is a chain, on to the next in the chain */
243
            priv->p = priv->p->next;
244
        } else {
245
          /* p is a single pbuf, set it to NULL so next time a new
246
           * pbuf is allocated */
247
            priv->p = NULL;
248
        }
249
      }
250
    }
251
  }
252
 
253
  return NULL;
254
}
255
 
256
#if !NO_SYS
257
/**
258
 * The SLIP input thread.
259
 *
260
 * Feed the IP layer with incoming packets
261
 *
262
 * @param nf the lwip network interface structure for this slipif
263
 */
264
static void
265
slipif_loop_thread(void *nf)
266
{
267
  struct pbuf *p;
268
  struct netif *netif = (struct netif *)nf;
269
 
270
  while (1) {
271
    p = slipif_input(netif, SLIP_BLOCK);
272
    if (p != NULL) {
273
      if (netif->input(p, netif) != ERR_OK) {
274
        pbuf_free(p);
275
        p = NULL;
276
      }
277
    }
278
  }
279
}
280
#endif /* !NO_SYS */
281
 
282
/**
283
 * SLIP netif initialization
284
 *
285
 * Call the arch specific sio_open and remember
286
 * the opened device in the state field of the netif.
287
 *
288
 * @param netif the lwip network interface structure for this slipif
289
 * @return ERR_OK if serial line could be opened,
290
 *         ERR_MEM if no memory could be allocated,
291
 *         ERR_IF is serial line couldn't be opened
292
 *
293
 * @note netif->num must contain the number of the serial port to open
294
 *       (0 by default)
295
 */
296
err_t
297
slipif_init(struct netif *netif)
298
{
299
  struct slipif_priv *priv;
300
 
301
  LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num));
302
 
303
  /* Allocate private data */
304
  priv = mem_malloc(sizeof(struct slipif_priv));
305
  if (!priv) {
306
    return ERR_MEM;
307
  }
308
 
309
  netif->name[0] = 's';
310
  netif->name[1] = 'l';
311
  netif->output = slipif_output;
312
  netif->mtu = SLIP_MAX_SIZE;
313
  netif->flags |= NETIF_FLAG_POINTTOPOINT;
314
 
315
  /* Try to open the serial port (netif->num contains the port number). */
316
  priv->sd = sio_open(netif->num);
317
  if (!priv->sd) {
318
    /* Opening the serial port failed. */
319
    mem_free(priv);
320
    return ERR_IF;
321
  }
322
 
323
  /* Initialize private data */
324
  priv->p = NULL;
325
  priv->q = NULL;
326
  priv->state = SLIP_RECV_NORMAL;
327
  priv->i = 0;
328
  priv->recved = 0;
329
 
330
  netif->state = priv;
331
 
332
  /* initialize the snmp variables and counters inside the struct netif
333
   * ifSpeed: no assumption can be made without knowing more about the
334
   * serial line!
335
   */
336
  NETIF_INIT_SNMP(netif, snmp_ifType_slip, 0);
337
 
338
  /* Create a thread to poll the serial line. */
339
  sys_thread_new(SLIPIF_THREAD_NAME, slipif_loop_thread, netif,
340
    SLIPIF_THREAD_STACKSIZE, SLIPIF_THREAD_PRIO);
341
  return ERR_OK;
342
}
343
 
344
/**
345
 * Polls the serial device and feeds the IP layer with incoming packets.
346
 *
347
 * @param netif The lwip network interface structure for this slipif
348
 */
349
void
350
slipif_poll(struct netif *netif)
351
{
352
  struct pbuf *p;
353
  struct slipif_priv *priv;
354
 
355
  LWIP_ASSERT("netif != NULL", (netif != NULL));
356
  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
357
 
358
  priv = netif->state;
359
 
360
  while ((p = slipif_input(netif, SLIP_DONTBLOCK)) != NULL) {
361
    if (netif->input(p, netif) != ERR_OK) {
362
      pbuf_free(p);
363
    }
364
  }
365
}
366
 
367
#endif /* LWIP_HAVE_SLIPIF */

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