FreeRTOS-RISCV/FreeRTOSv10.2.1/FreeRTOS/Demo/Common/ethernet/lwIP/netif/slipif.c

214 lines
5.6 KiB
C

/*
* 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/sio.h"
#define SLIP_END 0300
#define SLIP_ESC 0333
#define SLIP_ESC_END 0334
#define SLIP_ESC_ESC 0335
#define MAX_SIZE 1500
/**
* Send a pbuf doing the necessary SLIP encapsulation
*
* Uses the serial layer's sio_send()
*/
err_t
slipif_output(struct netif *netif, struct pbuf *p, struct ip_addr *ipaddr)
{
struct pbuf *q;
u16_t i;
u8_t c;
/* 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 0;
}
/**
* Handle the incoming SLIP stream character by character
*
* Poll the serial layer by calling sio_recv()
*
* @return The IP packet when SLIP_END is received
*/
static struct pbuf *
slipif_input(struct netif *netif)
{
u8_t c;
struct pbuf *p, *q;
u16_t recved;
u16_t i;
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. */
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:
if (p == NULL) {
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"));
}
if (q != NULL) {
pbuf_cat(q, p);
} else {
q = p;
}
}
if (p != NULL && recved < MAX_SIZE) {
((u8_t *)p->payload)[i] = c;
recved++;
i++;
if (i >= p->len) {
i = 0;
if (p->next != NULL && p->next->len > 0)
p = p->next;
else
p = NULL;
}
}
break;
}
}
return NULL;
}
/**
* The SLIP input thread.
*
* Feed the IP layer with incoming packets
*/
static void
slipif_loop(void *nf)
{
struct pbuf *p;
struct netif *netif = (struct netif *)nf;
while (1) {
p = slipif_input(netif);
netif->input(p, netif);
}
}
/**
* SLIP netif initialization
*
* Call the arch specific sio_open and remember
* the opened device in the state field of the netif.
*/
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 = 1500;
netif->flags = NETIF_FLAG_POINTTOPOINT;
netif->state = sio_open(netif->num);
if (!netif->state)
return ERR_IF;
sys_thread_new(slipif_loop, netif, SLIPIF_THREAD_PRIO);
return ERR_OK;
}