8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
35 * This file is built upon the file: src/arch/rtxc/netif/sioslip.c
37 * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>
41 * 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
45 #include "netif/slipif.h"
51 #include "lwip/pbuf.h"
53 #include "lwip/stats.h"
54 #include "lwip/snmp.h"
58 #define SLIP_DONTBLOCK 0
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 */
65 #define SLIP_MAX_SIZE 1500
67 enum slipif_recv_state {
74 /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
76 enum slipif_recv_state state;
81 * Send a pbuf doing the necessary SLIP encapsulation
83 * Uses the serial layer's sio_send()
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
91 slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
93 struct slipif_priv *priv;
98 LWIP_ASSERT("netif != NULL", (netif != NULL));
99 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
100 LWIP_ASSERT("p != NULL", (p != NULL));
102 LWIP_UNUSED_ARG(ipaddr);
106 /* Send pbuf out on the serial I/O device. */
107 sio_send(SLIP_END, priv->sd);
109 for (q = p; q != NULL; q = q->next) {
110 for (i = 0; i < q->len; i++) {
111 c = ((u8_t *)q->payload)[i];
114 sio_send(SLIP_ESC, priv->sd);
115 sio_send(SLIP_ESC_END, priv->sd);
118 sio_send(SLIP_ESC, priv->sd);
119 sio_send(SLIP_ESC_ESC, priv->sd);
122 sio_send(c, priv->sd);
127 sio_send(SLIP_END, priv->sd);
132 * Static function for easy use of blockig or non-blocking
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
142 slip_sio_read(sio_fd_t fd, u8_t* data, u32_t len, u8_t block)
145 return sio_read(fd, data, len);
147 return sio_tryread(fd, data, len);
152 * Handle the incoming SLIP stream character by character
154 * Poll the serial layer by calling sio_read() or sio_tryread().
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
163 slipif_input(struct netif *netif, u8_t block)
165 struct slipif_priv *priv;
169 LWIP_ASSERT("netif != NULL", (netif != NULL));
170 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
174 while (slip_sio_read(priv->sd, &c, 1, block) > 0) {
175 switch (priv->state) {
176 case SLIP_RECV_NORMAL:
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);
184 LINK_STATS_INC(link.recv);
186 LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet\n"));
188 priv->p = priv->q = NULL;
189 priv->i = priv->recved = 0;
194 priv->state = SLIP_RECV_ESCAPE;
198 case SLIP_RECV_ESCAPE:
207 priv->state = SLIP_RECV_NORMAL;
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);
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 */
224 if (priv->q != NULL) {
225 /* 'chain' the pbuf to the existing chain */
226 pbuf_cat(priv->q, priv->p);
228 /* p is the first pbuf in the chain */
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;
238 if (priv->i >= priv->p->len) {
239 /* on to the next pbuf */
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;
245 /* p is a single pbuf, set it to NULL so next time a new
246 * pbuf is allocated */
258 * The SLIP input thread.
260 * Feed the IP layer with incoming packets
262 * @param nf the lwip network interface structure for this slipif
265 slipif_loop_thread(void *nf)
268 struct netif *netif = (struct netif *)nf;
271 p = slipif_input(netif, SLIP_BLOCK);
273 if (netif->input(p, netif) != ERR_OK) {
283 * SLIP netif initialization
285 * Call the arch specific sio_open and remember
286 * the opened device in the state field of the netif.
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
293 * @note netif->num must contain the number of the serial port to open
297 slipif_init(struct netif *netif)
299 struct slipif_priv *priv;
301 LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)netif->num));
303 /* Allocate private data */
304 priv = mem_malloc(sizeof(struct slipif_priv));
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;
315 /* Try to open the serial port (netif->num contains the port number). */
316 priv->sd = sio_open(netif->num);
318 /* Opening the serial port failed. */
323 /* Initialize private data */
326 priv->state = SLIP_RECV_NORMAL;
332 /* initialize the snmp variables and counters inside the struct netif
333 * ifSpeed: no assumption can be made without knowing more about the
336 NETIF_INIT_SNMP(netif, snmp_ifType_slip, 0);
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);
345 * Polls the serial device and feeds the IP layer with incoming packets.
347 * @param netif The lwip network interface structure for this slipif
350 slipif_poll(struct netif *netif)
353 struct slipif_priv *priv;
355 LWIP_ASSERT("netif != NULL", (netif != NULL));
356 LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
360 while ((p = slipif_input(netif, SLIP_DONTBLOCK)) != NULL) {
361 if (netif->input(p, netif) != ERR_OK) {
367 #endif /* LWIP_HAVE_SLIPIF */