--- /dev/null
+/**
+ * @file
+ * SLIP Interface
+ *
+ */
+
+/*
+ * 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/snmp.h"
+#include "lwip/sio.h"
+
+#define SLIP_END 0300 /* 0xC0 */
+#define SLIP_ESC 0333 /* 0xDB */
+#define SLIP_ESC_END 0334 /* 0xDC */
+#define SLIP_ESC_ESC 0335 /* 0xDD */
+
+#define MAX_SIZE 1500
+
+/**
+ * Send a pbuf doing the necessary SLIP encapsulation
+ *
+ * Uses the serial layer's sio_send()
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @param p the pbuf chaing packet to send
+ * @param ipaddr the ip address to send the packet to (not used for slipif)
+ * @return always returns ERR_OK since the serial layer does not provide return values
+ */
+err_t
+slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
+{
+ struct pbuf *q;
+ u16_t i;
+ u8_t c;
+
+ LWIP_ASSERT("netif != NULL", (netif != NULL));
+ LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+ LWIP_ASSERT("p != NULL", (p != NULL));
+
+ LWIP_UNUSED_ARG(ipaddr);
+
+ /* 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 ERR_OK;
+}
+
+/**
+ * Handle the incoming SLIP stream character by character
+ *
+ * Poll the serial layer by calling sio_recv()
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @return The IP packet when SLIP_END is received
+ */
+static struct pbuf *
+slipif_input(struct netif *netif)
+{
+ u8_t c;
+ /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
+ struct pbuf *p, *q;
+ u16_t recved;
+ u16_t i;
+
+ LWIP_ASSERT("netif != NULL", (netif != NULL));
+ LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+
+ 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. */
+ /* Trim the pbuf to the size of the received 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:
+ /* byte received, packet not yet completely received */
+ if (p == NULL) {
+ /* allocate a new pbuf */
+ 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"));
+ /* don't process any further since we got no pbuf to receive to */
+ break;
+ }
+
+ if (q != NULL) {
+ /* 'chain' the pbuf to the existing chain */
+ pbuf_cat(q, p);
+ } else {
+ /* p is the first pbuf in the chain */
+ q = p;
+ }
+ }
+
+ /* this automatically drops bytes if > MAX_SIZE */
+ if ((p != NULL) && (recved <= MAX_SIZE)) {
+ ((u8_t *)p->payload)[i] = c;
+ recved++;
+ i++;
+ if (i >= p->len) {
+ /* on to the next pbuf */
+ i = 0;
+ if (p->next != NULL && p->next->len > 0) {
+ /* p is a chain, on to the next in the chain */
+ p = p->next;
+ } else {
+ /* p is a single pbuf, set it to NULL so next time a new
+ * pbuf is allocated */
+ p = NULL;
+ }
+ }
+ }
+ break;
+ }
+ }
+ return NULL;
+}
+
+#if !NO_SYS
+/**
+ * The SLIP input thread.
+ *
+ * Feed the IP layer with incoming packets
+ *
+ * @param nf the lwip network interface structure for this slipif
+ */
+static void
+slipif_loop(void *nf)
+{
+ struct pbuf *p;
+ struct netif *netif = (struct netif *)nf;
+
+ while (1) {
+ p = slipif_input(netif);
+ if (p != NULL) {
+ if (netif->input(p, netif) != ERR_OK) {
+ pbuf_free(p);
+ p = NULL;
+ }
+ }
+ }
+}
+#endif /* !NO_SYS */
+
+/**
+ * SLIP netif initialization
+ *
+ * Call the arch specific sio_open and remember
+ * the opened device in the state field of the netif.
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @return ERR_OK if serial line could be opened,
+ * ERR_IF is serial line couldn't be opened
+ *
+ * @note netif->num must contain the number of the serial port to open
+ * (0 by default)
+ */
+err_t
+slipif_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 = MAX_SIZE;
+ netif->flags = NETIF_FLAG_POINTTOPOINT;
+
+ /* Try to open the serial port (netif->num contains the port number). */
+ netif->state = sio_open(netif->num);
+ if (!netif->state) {
+ /* Opening the serial port failed. */
+ return ERR_IF;
+ }
+
+ /* initialize the snmp variables and counters inside the struct netif
+ * ifSpeed: no assumption can be made without knowing more about the
+ * serial line!
+ */
+ NETIF_INIT_SNMP(netif, snmp_ifType_slip, 0);
+
+ /* Create a thread to poll the serial line. */
+ sys_thread_new(SLIPIF_THREAD_NAME, slipif_loop, netif, SLIPIF_THREAD_STACKSIZE, SLIPIF_THREAD_PRIO);
+ return ERR_OK;
+}
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