| /** |
| * @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; |
| } |