source: UsbWattMeter/trunk/lwip-1.4.1/src/netif/slipif.c@ 164

Last change on this file since 164 was 164, checked in by coas-nagasima, 6 years ago

TOPPERS/ECNLサンプルアプリ「USB充電器電力計」を追加

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1/**
2 * @file
3 * 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.
19 * 3. Neither the name of the Institute nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
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
27 * 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
33 * SUCH DAMAGE.
34 *
35 * This file is built upon the file: src/arch/rtxc/netif/sioslip.c
36 *
37 * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>
38 * Simon Goldschmidt
39 *
40 * Usage: This netif can be used in three ways:
41 * 1) For NO_SYS==0, an RX thread can be used which blocks on sio_read()
42 * until data is received.
43 * 2) In your main loop, call slipif_poll() to check for new RX bytes,
44 * completed packets are fed into netif->input().
45 * 3) Call slipif_received_byte[s]() from your serial RX ISR and
46 * slipif_process_rxqueue() from your main loop. ISR level decodes
47 * packets and puts completed packets on a queue which is fed into
48 * the stack from the main loop (needs SYS_LIGHTWEIGHT_PROT for
49 * pbuf_alloc to work on ISR level!).
50 *
51 */
52
53/*
54 * This is an arch independent SLIP netif. The specific serial hooks must be
55 * provided by another file. They are sio_open, sio_read/sio_tryread and sio_send
56 */
57
58#include "netif/slipif.h"
59#include "lwip/opt.h"
60
61#if LWIP_HAVE_SLIPIF
62
63#include "lwip/def.h"
64#include "lwip/pbuf.h"
65#include "lwip/stats.h"
66#include "lwip/snmp.h"
67#include "lwip/sio.h"
68#include "lwip/sys.h"
69
70#define SLIP_END 0xC0 /* 0300: start and end of every packet */
71#define SLIP_ESC 0xDB /* 0333: escape start (one byte escaped data follows) */
72#define SLIP_ESC_END 0xDC /* 0334: following escape: original byte is 0xC0 (END) */
73#define SLIP_ESC_ESC 0xDD /* 0335: following escape: original byte is 0xDB (ESC) */
74
75/** Maximum packet size that is received by this netif */
76#ifndef SLIP_MAX_SIZE
77#define SLIP_MAX_SIZE 1500
78#endif
79
80/** Define this to the interface speed for SNMP
81 * (sio_fd is the sio_fd_t returned by sio_open).
82 * The default value of zero means 'unknown'.
83 */
84#ifndef SLIP_SIO_SPEED
85#define SLIP_SIO_SPEED(sio_fd) 0
86#endif
87
88enum slipif_recv_state {
89 SLIP_RECV_NORMAL,
90 SLIP_RECV_ESCAPE,
91};
92
93struct slipif_priv {
94 sio_fd_t sd;
95 /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
96 struct pbuf *p, *q;
97 u8_t state;
98 u16_t i, recved;
99#if SLIP_RX_FROM_ISR
100 struct pbuf *rxpackets;
101#endif
102};
103
104/**
105 * Send a pbuf doing the necessary SLIP encapsulation
106 *
107 * Uses the serial layer's sio_send()
108 *
109 * @param netif the lwip network interface structure for this slipif
110 * @param p the pbuf chaing packet to send
111 * @param ipaddr the ip address to send the packet to (not used for slipif)
112 * @return always returns ERR_OK since the serial layer does not provide return values
113 */
114err_t
115slipif_output(struct netif *netif, struct pbuf *p, ip_addr_t *ipaddr)
116{
117 struct slipif_priv *priv;
118 struct pbuf *q;
119 u16_t i;
120 u8_t c;
121
122 LWIP_ASSERT("netif != NULL", (netif != NULL));
123 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
124 LWIP_ASSERT("p != NULL", (p != NULL));
125
126 LWIP_UNUSED_ARG(ipaddr);
127
128 LWIP_DEBUGF(SLIP_DEBUG, ("slipif_output(%"U16_F"): sending %"U16_F" bytes\n", (u16_t)netif->num, p->tot_len));
129 priv = netif->state;
130
131 /* Send pbuf out on the serial I/O device. */
132 /* Start with packet delimiter. */
133 sio_send(SLIP_END, priv->sd);
134
135 for (q = p; q != NULL; q = q->next) {
136 for (i = 0; i < q->len; i++) {
137 c = ((u8_t *)q->payload)[i];
138 switch (c) {
139 case SLIP_END:
140 /* need to escape this byte (0xC0 -> 0xDB, 0xDC) */
141 sio_send(SLIP_ESC, priv->sd);
142 sio_send(SLIP_ESC_END, priv->sd);
143 break;
144 case SLIP_ESC:
145 /* need to escape this byte (0xDB -> 0xDB, 0xDD) */
146 sio_send(SLIP_ESC, priv->sd);
147 sio_send(SLIP_ESC_ESC, priv->sd);
148 break;
149 default:
150 /* normal byte - no need for escaping */
151 sio_send(c, priv->sd);
152 break;
153 }
154 }
155 }
156 /* End with packet delimiter. */
157 sio_send(SLIP_END, priv->sd);
158 return ERR_OK;
159}
160
161/**
162 * Handle the incoming SLIP stream character by character
163 *
164 * @param netif the lwip network interface structure for this slipif
165 * @param c received character (multiple calls to this function will
166 * return a complete packet, NULL is returned before - used for polling)
167 * @return The IP packet when SLIP_END is received
168 */
169static struct pbuf*
170slipif_rxbyte(struct netif *netif, u8_t c)
171{
172 struct slipif_priv *priv;
173 struct pbuf *t;
174
175 LWIP_ASSERT("netif != NULL", (netif != NULL));
176 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
177
178 priv = netif->state;
179
180 switch (priv->state) {
181 case SLIP_RECV_NORMAL:
182 switch (c) {
183 case SLIP_END:
184 if (priv->recved > 0) {
185 /* Received whole packet. */
186 /* Trim the pbuf to the size of the received packet. */
187 pbuf_realloc(priv->q, priv->recved);
188
189 LINK_STATS_INC(link.recv);
190
191 LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet (%"U16_F" bytes)\n", priv->recved));
192 t = priv->q;
193 priv->p = priv->q = NULL;
194 priv->i = priv->recved = 0;
195 return t;
196 }
197 return NULL;
198 case SLIP_ESC:
199 priv->state = SLIP_RECV_ESCAPE;
200 return NULL;
201 } /* end switch (c) */
202 break;
203 case SLIP_RECV_ESCAPE:
204 /* un-escape END or ESC bytes, leave other bytes
205 (although that would be a protocol error) */
206 switch (c) {
207 case SLIP_ESC_END:
208 c = SLIP_END;
209 break;
210 case SLIP_ESC_ESC:
211 c = SLIP_ESC;
212 break;
213 }
214 priv->state = SLIP_RECV_NORMAL;
215 break;
216 } /* end switch (priv->state) */
217
218 /* byte received, packet not yet completely received */
219 if (priv->p == NULL) {
220 /* allocate a new pbuf */
221 LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
222 priv->p = pbuf_alloc(PBUF_LINK, (PBUF_POOL_BUFSIZE - PBUF_LINK_HLEN), PBUF_POOL);
223
224 if (priv->p == NULL) {
225 LINK_STATS_INC(link.drop);
226 LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));
227 /* don't process any further since we got no pbuf to receive to */
228 return NULL;
229 }
230
231 if (priv->q != NULL) {
232 /* 'chain' the pbuf to the existing chain */
233 pbuf_cat(priv->q, priv->p);
234 } else {
235 /* p is the first pbuf in the chain */
236 priv->q = priv->p;
237 }
238 }
239
240 /* this automatically drops bytes if > SLIP_MAX_SIZE */
241 if ((priv->p != NULL) && (priv->recved <= SLIP_MAX_SIZE)) {
242 ((u8_t *)priv->p->payload)[priv->i] = c;
243 priv->recved++;
244 priv->i++;
245 if (priv->i >= priv->p->len) {
246 /* on to the next pbuf */
247 priv->i = 0;
248 if (priv->p->next != NULL && priv->p->next->len > 0) {
249 /* p is a chain, on to the next in the chain */
250 priv->p = priv->p->next;
251 } else {
252 /* p is a single pbuf, set it to NULL so next time a new
253 * pbuf is allocated */
254 priv->p = NULL;
255 }
256 }
257 }
258 return NULL;
259}
260
261/** Like slipif_rxbyte, but passes completed packets to netif->input
262 *
263 * @param netif The lwip network interface structure for this slipif
264 * @param data received character
265 */
266static void
267slipif_rxbyte_input(struct netif *netif, u8_t c)
268{
269 struct pbuf *p;
270 p = slipif_rxbyte(netif, c);
271 if (p != NULL) {
272 if (netif->input(p, netif) != ERR_OK) {
273 pbuf_free(p);
274 }
275 }
276}
277
278#if SLIP_USE_RX_THREAD
279/**
280 * The SLIP input thread.
281 *
282 * Feed the IP layer with incoming packets
283 *
284 * @param nf the lwip network interface structure for this slipif
285 */
286static void
287slipif_loop_thread(void *nf)
288{
289 u8_t c;
290 struct netif *netif = (struct netif *)nf;
291 struct slipif_priv *priv = (struct slipif_priv *)netif->state;
292
293 while (1) {
294 if (sio_read(priv->sd, &c, 1) > 0) {
295 slipif_rxbyte_input(netif, c);
296 }
297 }
298}
299#endif /* SLIP_USE_RX_THREAD */
300
301/**
302 * SLIP netif initialization
303 *
304 * Call the arch specific sio_open and remember
305 * the opened device in the state field of the netif.
306 *
307 * @param netif the lwip network interface structure for this slipif
308 * @return ERR_OK if serial line could be opened,
309 * ERR_MEM if no memory could be allocated,
310 * ERR_IF is serial line couldn't be opened
311 *
312 * @note netif->num must contain the number of the serial port to open
313 * (0 by default). If netif->state is != NULL, it is interpreted as an
314 * u8_t pointer pointing to the serial port number instead of netif->num.
315 *
316 */
317err_t
318slipif_init(struct netif *netif)
319{
320 struct slipif_priv *priv;
321 u8_t sio_num;
322
323 LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num));
324
325 /* Allocate private data */
326 priv = (struct slipif_priv *)mem_malloc(sizeof(struct slipif_priv));
327 if (!priv) {
328 return ERR_MEM;
329 }
330
331 netif->name[0] = 's';
332 netif->name[1] = 'l';
333 netif->output = slipif_output;
334 netif->mtu = SLIP_MAX_SIZE;
335 netif->flags |= NETIF_FLAG_POINTTOPOINT;
336
337 /* netif->state or netif->num contain the port number */
338 if (netif->state != NULL) {
339 sio_num = *(u8_t*)netif->state;
340 } else {
341 sio_num = netif->num;
342 }
343 /* Try to open the serial port. */
344 priv->sd = sio_open(sio_num);
345 if (!priv->sd) {
346 /* Opening the serial port failed. */
347 mem_free(priv);
348 return ERR_IF;
349 }
350
351 /* Initialize private data */
352 priv->p = NULL;
353 priv->q = NULL;
354 priv->state = SLIP_RECV_NORMAL;
355 priv->i = 0;
356 priv->recved = 0;
357#if SLIP_RX_FROM_ISR
358 priv->rxpackets = NULL;
359#endif
360
361 netif->state = priv;
362
363 /* initialize the snmp variables and counters inside the struct netif */
364 NETIF_INIT_SNMP(netif, snmp_ifType_slip, SLIP_SIO_SPEED(priv->sd));
365
366#if SLIP_USE_RX_THREAD
367 /* Create a thread to poll the serial line. */
368 sys_thread_new(SLIPIF_THREAD_NAME, slipif_loop_thread, netif,
369 SLIPIF_THREAD_STACKSIZE, SLIPIF_THREAD_PRIO);
370#endif /* SLIP_USE_RX_THREAD */
371 return ERR_OK;
372}
373
374/**
375 * Polls the serial device and feeds the IP layer with incoming packets.
376 *
377 * @param netif The lwip network interface structure for this slipif
378 */
379void
380slipif_poll(struct netif *netif)
381{
382 u8_t c;
383 struct slipif_priv *priv;
384
385 LWIP_ASSERT("netif != NULL", (netif != NULL));
386 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
387
388 priv = (struct slipif_priv *)netif->state;
389
390 while (sio_tryread(priv->sd, &c, 1) > 0) {
391 slipif_rxbyte_input(netif, c);
392 }
393}
394
395#if SLIP_RX_FROM_ISR
396/**
397 * Feeds the IP layer with incoming packets that were receive
398 *
399 * @param netif The lwip network interface structure for this slipif
400 */
401void
402slipif_process_rxqueue(struct netif *netif)
403{
404 struct slipif_priv *priv;
405 SYS_ARCH_DECL_PROTECT(old_level);
406
407 LWIP_ASSERT("netif != NULL", (netif != NULL));
408 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
409
410 priv = (struct slipif_priv *)netif->state;
411
412 SYS_ARCH_PROTECT(old_level);
413 while (priv->rxpackets != NULL) {
414 struct pbuf *p = priv->rxpackets;
415#if SLIP_RX_QUEUE
416 /* dequeue packet */
417 struct pbuf *q = p;
418 while ((q->len != q->tot_len) && (q->next != NULL)) {
419 q = q->next;
420 }
421 priv->rxpackets = q->next;
422 q->next = NULL;
423#else /* SLIP_RX_QUEUE */
424 priv->rxpackets = NULL;
425#endif /* SLIP_RX_QUEUE */
426 SYS_ARCH_UNPROTECT(old_level);
427 if (netif->input(p, netif) != ERR_OK) {
428 pbuf_free(p);
429 }
430 SYS_ARCH_PROTECT(old_level);
431 }
432}
433
434/** Like slipif_rxbyte, but queues completed packets.
435 *
436 * @param netif The lwip network interface structure for this slipif
437 * @param data Received serial byte
438 */
439static void
440slipif_rxbyte_enqueue(struct netif *netif, u8_t data)
441{
442 struct pbuf *p;
443 struct slipif_priv *priv = (struct slipif_priv *)netif->state;
444 SYS_ARCH_DECL_PROTECT(old_level);
445
446 p = slipif_rxbyte(netif, data);
447 if (p != NULL) {
448 SYS_ARCH_PROTECT(old_level);
449 if (priv->rxpackets != NULL) {
450#if SLIP_RX_QUEUE
451 /* queue multiple pbufs */
452 struct pbuf *q = p;
453 while(q->next != NULL) {
454 q = q->next;
455 }
456 q->next = p;
457 } else {
458#else /* SLIP_RX_QUEUE */
459 pbuf_free(priv->rxpackets);
460 }
461 {
462#endif /* SLIP_RX_QUEUE */
463 priv->rxpackets = p;
464 }
465 SYS_ARCH_UNPROTECT(old_level);
466 }
467}
468
469/**
470 * Process a received byte, completed packets are put on a queue that is
471 * fed into IP through slipif_process_rxqueue().
472 *
473 * This function can be called from ISR if SYS_LIGHTWEIGHT_PROT is enabled.
474 *
475 * @param netif The lwip network interface structure for this slipif
476 * @param data received character
477 */
478void
479slipif_received_byte(struct netif *netif, u8_t data)
480{
481 LWIP_ASSERT("netif != NULL", (netif != NULL));
482 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
483 slipif_rxbyte_enqueue(netif, data);
484}
485
486/**
487 * Process multiple received byte, completed packets are put on a queue that is
488 * fed into IP through slipif_process_rxqueue().
489 *
490 * This function can be called from ISR if SYS_LIGHTWEIGHT_PROT is enabled.
491 *
492 * @param netif The lwip network interface structure for this slipif
493 * @param data received character
494 * @param len Number of received characters
495 */
496void
497slipif_received_bytes(struct netif *netif, u8_t *data, u8_t len)
498{
499 u8_t i;
500 u8_t *rxdata = data;
501 LWIP_ASSERT("netif != NULL", (netif != NULL));
502 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
503
504 for (i = 0; i < len; i++, rxdata++) {
505 slipif_rxbyte_enqueue(netif, *rxdata);
506 }
507}
508#endif /* SLIP_RX_FROM_ISR */
509
510#endif /* LWIP_HAVE_SLIPIF */
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