working on lwip

mission/netif/CMakeLists.txt

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+target_sources(${OBSW_NAME} PRIVATE slipif.c)

mission/netif/slipif.c

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+/**
+ * @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>
+ *         Simon Goldschmidt
+ */
+
+
+/**
+ * @defgroup slipif SLIP
+ * @ingroup netifs
+ *
+ * This is an arch independent SLIP netif. The specific serial hooks must be
+ * provided by another file. They are sio_open, sio_read/sio_tryread and sio_send
+ *
+ * Usage: This netif can be used in three ways:
+ *        1. For NO_SYS==0, an RX thread can be used which blocks on sio_read()
+ *           until data is received.
+ *        2. In your main loop, call slipif_poll() to check for new RX bytes,
+ *           completed packets are fed into netif->input().
+ *        3. Call slipif_received_byte[s]() from your serial RX ISR and
+ *           slipif_process_rxqueue() from your main loop. ISR level decodes
+ *           packets and puts completed packets on a queue which is fed into
+ *           the stack from the main loop (needs SYS_LIGHTWEIGHT_PROT for
+ *           pbuf_alloc to work on ISR level!).
+ *
+ */
+
+#include "slipif.h"
+#include "lwip/opt.h"
+
+#include "lwip/def.h"
+#include "lwip/pbuf.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "lwip/sys.h"
+
+#define SLIP_END     0xC0 /* 0300: start and end of every packet */
+#define SLIP_ESC     0xDB /* 0333: escape start (one byte escaped data follows) */
+#define SLIP_ESC_END 0xDC /* 0334: following escape: original byte is 0xC0 (END) */
+#define SLIP_ESC_ESC 0xDD /* 0335: following escape: original byte is 0xDB (ESC) */
+
+/** Maximum packet size that is received by this netif */
+#ifndef SLIP_MAX_SIZE
+#define SLIP_MAX_SIZE 1500
+#endif
+
+#ifndef SLIP_CHUNK_SIZE
+#define SLIP_CHUNK_SIZE 120
+#endif
+
+enum slipif_recv_state {
+  SLIP_RECV_NORMAL,
+  SLIP_RECV_ESCAPE
+};
+
+
+
+static void 
+slipif_send_chunk(uint8_t c, int fd, uint8_t *chunk, size_t *current_index, size_t chunksize, int flush){
+    if (*current_index >= chunksize) {
+      write(0,"stra", 5);
+        //chunk is already full, send it and reset
+        write(fd, chunk, chunksize);
+        *current_index = 0;
+    }
+    // add byte to chunk, (can not be full, we checked)
+    if (*current_index < chunksize) {
+        chunk[*current_index] = c;
+        (*current_index)++;
+    }
+    // if either chunk is full or we shall flush, send it
+    if ((*current_index >= chunksize) || ( flush != 0)) {
+      write(0,"full", 5);
+       write(fd, chunk, *current_index);
+        *current_index = 0;
+    }
+}
+
+
+/**
+ * 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 chain packet to send
+ * @return always returns ERR_OK since the serial layer does not provide return values
+ */
+static err_t
+slipif_output(struct netif *netif, struct pbuf *p)
+{
+  struct slipif_priv *priv;
+  struct pbuf *q;
+  u16_t i;
+  u8_t c;
+
+  uint8_t chunk[SLIP_CHUNK_SIZE];
+  size_t current_index = 0;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+  LWIP_ASSERT("p != NULL", (p != NULL));
+
+  LWIP_DEBUGF(SLIP_DEBUG, ("slipif_output: sending %"U16_F" bytes\n", p->tot_len));
+  priv = (struct slipif_priv *)netif->state;
+
+  /* Send pbuf out on the serial I/O device. */
+  /* Start with packet delimiter. */
+  slipif_send_chunk(SLIP_END, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+
+  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:
+          /* need to escape this byte (0xC0 -> 0xDB, 0xDC) */
+          slipif_send_chunk(SLIP_ESC, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          slipif_send_chunk(SLIP_ESC_END, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          break;
+        case SLIP_ESC:
+          /* need to escape this byte (0xDB -> 0xDB, 0xDD) */
+          slipif_send_chunk(SLIP_ESC, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          slipif_send_chunk(SLIP_ESC_ESC, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          break;
+        default:
+          /* normal byte - no need for escaping */
+          slipif_send_chunk(c, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          break;
+      }
+    }
+  }
+  /* End with packet delimiter, flush the chunk */
+  slipif_send_chunk(SLIP_END, priv->fd, chunk, &current_index, sizeof(chunk), 1);
+  return ERR_OK;
+}
+
+#if LWIP_IPV4
+/**
+ * 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 chain 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
+ */
+static err_t
+slipif_output_v4(struct netif *netif, struct pbuf *p, const ip4_addr_t *ipaddr)
+{
+  LWIP_UNUSED_ARG(ipaddr);
+  return slipif_output(netif, p);
+}
+#endif /* LWIP_IPV4 */
+
+#if LWIP_IPV6
+/**
+ * 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 chain 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
+ */
+static err_t
+slipif_output_v6(struct netif *netif, struct pbuf *p, const ip6_addr_t *ipaddr)
+{
+  LWIP_UNUSED_ARG(ipaddr);
+  return slipif_output(netif, p);
+}
+#endif /* LWIP_IPV6 */
+
+/**
+ * Handle the incoming SLIP stream character by character
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @param c received character (multiple calls to this function will
+ *        return a complete packet, NULL is returned before - used for polling)
+ * @return The IP packet when SLIP_END is received
+ */
+static struct pbuf *
+slipif_rxbyte(struct netif *netif, u8_t c)
+{
+  struct slipif_priv *priv;
+  struct pbuf *t;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+
+  priv = (struct slipif_priv *)netif->state;
+
+  switch (priv->state) {
+    case SLIP_RECV_NORMAL:
+      switch (c) {
+        case SLIP_END:
+          if (priv->recved > 0) {
+            /* Received whole packet. */
+            /* Trim the pbuf to the size of the received packet. */
+            pbuf_realloc(priv->q, priv->recved);
+
+            LINK_STATS_INC(link.recv);
+
+            LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet (%"U16_F" bytes)\n", priv->recved));
+            t = priv->q;
+            priv->p = priv->q = NULL;
+            priv->i = priv->recved = 0;
+            return t;
+          }
+          return NULL;
+        case SLIP_ESC:
+          priv->state = SLIP_RECV_ESCAPE;
+          return NULL;
+        default:
+          break;
+      } /* end switch (c) */
+      break;
+    case SLIP_RECV_ESCAPE:
+      /* un-escape END or ESC bytes, leave other bytes
+         (although that would be a protocol error) */
+      switch (c) {
+        case SLIP_ESC_END:
+          c = SLIP_END;
+          break;
+        case SLIP_ESC_ESC:
+          c = SLIP_ESC;
+          break;
+        default:
+          break;
+      }
+      priv->state = SLIP_RECV_NORMAL;
+      break;
+    default:
+      break;
+  } /* end switch (priv->state) */
+
+  /* byte received, packet not yet completely received */
+  if (priv->p == NULL) {
+    /* allocate a new pbuf */
+    LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
+    priv->p = pbuf_alloc(PBUF_LINK, (PBUF_POOL_BUFSIZE - PBUF_LINK_HLEN - PBUF_LINK_ENCAPSULATION_HLEN), PBUF_POOL);
+
+    if (priv->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 */
+      return NULL;
+    }
+
+    if (priv->q != NULL) {
+      /* 'chain' the pbuf to the existing chain */
+      pbuf_cat(priv->q, priv->p);
+    } else {
+      /* p is the first pbuf in the chain */
+      priv->q = priv->p;
+    }
+  }
+
+  /* this automatically drops bytes if > SLIP_MAX_SIZE */
+  if ((priv->p != NULL) && (priv->recved <= SLIP_MAX_SIZE)) {
+    ((u8_t *)priv->p->payload)[priv->i] = c;
+    priv->recved++;
+    priv->i++;
+    if (priv->i >= priv->p->len) {
+      /* on to the next pbuf */
+      priv->i = 0;
+      if (priv->p->next != NULL && priv->p->next->len > 0) {
+        /* p is a chain, on to the next in the chain */
+        priv->p = priv->p->next;
+      } else {
+        /* p is a single pbuf, set it to NULL so next time a new
+         * pbuf is allocated */
+        priv->p = NULL;
+      }
+    }
+  }
+  return NULL;
+}
+
+/** Like slipif_rxbyte, but passes completed packets to netif->input
+ *
+ * @param netif The lwip network interface structure for this slipif
+ * @param c received character
+ */
+static void
+slipif_rxbyte_input(struct netif *netif, u8_t c)
+{
+  struct pbuf *p;
+  p = slipif_rxbyte(netif, c);
+  if (p != NULL) {
+    if (netif->input(p, netif) != ERR_OK) {
+      pbuf_free(p);
+    }
+  }
+}
+
+
+/**
+ * @ingroup slipif
+ * 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_MEM if no memory could be allocated,
+ *         ERR_IF is serial line couldn't be opened
+ *
+ * @note If netif->state is interpreted as an u8_t serial port number.
+ *
+ */
+err_t
+slipif_init(struct netif *netif)
+{
+  struct slipif_priv *priv;
+
+  LWIP_ASSERT("slipif needs an input callback", netif->input != NULL);
+
+  LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)sio_num));
+
+
+  netif->name[0] = 's';
+  netif->name[1] = 'l';
+#if LWIP_IPV4
+  netif->output = slipif_output_v4;
+#endif /* LWIP_IPV4 */
+#if LWIP_IPV6
+  netif->output_ip6 = slipif_output_v6;
+#endif /* LWIP_IPV6 */
+  netif->mtu = SLIP_MAX_SIZE;
+
+  /* private data needs to be allocated by user and passed via state (see netif_add()) */
+  priv = netif->state;
+  /* Initialize private data */
+  priv->p = NULL;
+  priv->q = NULL;
+  priv->state = SLIP_RECV_NORMAL;
+  priv->i = 0;
+  priv->recved = 0;
+  
+  LWIP_ASSERT("slipif private data fd needs to be initialized before calling netif_add()", priv->fd != 0);
+
+  
+
+  /* initialize the snmp variables and counters inside the struct netif */
+  MIB2_INIT_NETIF(netif, snmp_ifType_slip, SLIP_SIO_SPEED(priv->sd));
+
+  return ERR_OK;
+}
+
+/**
+ * @ingroup slipif
+ * Polls the serial device and feeds the IP layer with incoming packets.
+ *
+ * @param netif The lwip network interface structure for this slipif
+ */
+void
+slipif_poll(struct netif *netif)
+{
+  struct slipif_priv *priv;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+
+  priv = (struct slipif_priv *)netif->state;
+
+  uint8_t chunk[SLIP_CHUNK_SIZE];
+  int read_bytes = read(priv->fd, chunk, sizeof(chunk));
+
+  for (int i = 0; i < read_bytes; i++){
+    slipif_rxbyte_input(netif, chunk[i]);
+  }
+}

mission/netif/slipif.h

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+#pragma once
+
+#include "lwip/opt.h"
+#include "lwip/netif.h"
+
+struct slipif_priv {
+  int fd;
+  /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
+  struct pbuf *p, *q;
+  u8_t state;
+  u16_t i, recved;
+};
+
+err_t slipif_init(struct netif * netif);
+void slipif_poll(struct netif *netif);