initial commit of lk (little kernel) project
diff --git a/lib/lwip/src/netif/ethernetif.c b/lib/lwip/src/netif/ethernetif.c
new file mode 100644
index 0000000..0c14e8d
--- /dev/null
+++ b/lib/lwip/src/netif/ethernetif.c
@@ -0,0 +1,306 @@
+/*
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 part of the lwIP TCP/IP stack.
+ * 
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+/*
+ * This file is a skeleton for developing Ethernet network interface
+ * drivers for lwIP. Add code to the low_level functions and do a
+ * search-and-replace for the word "ethernetif" to replace it with
+ * something that better describes your network interface.
+ */
+
+#include "lwip/opt.h"
+#include "lwip/def.h"
+#include "lwip/mem.h"
+#include "lwip/pbuf.h"
+#include "lwip/sys.h"
+#include <lwip/stats.h>
+
+#include "netif/etharp.h"
+
+/* Define those to better describe your network interface. */
+#define IFNAME0 'e'
+#define IFNAME1 'n'
+
+struct ethernetif {
+  struct eth_addr *ethaddr;
+  /* Add whatever per-interface state that is needed here. */
+};
+
+static const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
+
+/* Forward declarations. */
+static void  ethernetif_input(struct netif *netif);
+static err_t ethernetif_output(struct netif *netif, struct pbuf *p,
+             struct ip_addr *ipaddr);
+
+static void
+low_level_init(struct netif *netif)
+{
+  struct ethernetif *ethernetif = netif->state;
+  
+  /* set MAC hardware address length */
+  netif->hwaddr_len = 6;
+
+  /* set MAC hardware address */
+  netif->hwaddr[0] = ;
+  ...
+  netif->hwaddr[5] = ;
+
+  /* maximum transfer unit */
+  netif->mtu = 1500;
+  
+  /* broadcast capability */
+  netif->flags = NETIF_FLAG_BROADCAST;
+ 
+  /* Do whatever else is needed to initialize interface. */  
+}
+
+/*
+ * low_level_output():
+ *
+ * Should do the actual transmission of the packet. The packet is
+ * contained in the pbuf that is passed to the function. This pbuf
+ * might be chained.
+ *
+ */
+
+static err_t
+low_level_output(struct netif *netif, struct pbuf *p)
+{
+  struct ethernetif *ethernetif = netif->state;
+  struct pbuf *q;
+
+  initiate transfer();
+  
+#if ETH_PAD_SIZE
+  pbuf_header(p, -ETH_PAD_SIZE);			/* drop the padding word */
+#endif
+
+  for(q = p; q != NULL; q = q->next) {
+    /* Send the data from the pbuf to the interface, one pbuf at a
+       time. The size of the data in each pbuf is kept in the ->len
+       variable. */
+    send data from(q->payload, q->len);
+  }
+
+  signal that packet should be sent();
+
+#if ETH_PAD_SIZE
+  pbuf_header(p, ETH_PAD_SIZE);			/* reclaim the padding word */
+#endif
+  
+#if LINK_STATS
+  lwip_stats.link.xmit++;
+#endif /* LINK_STATS */      
+
+  return ERR_OK;
+}
+
+/*
+ * low_level_input():
+ *
+ * Should allocate a pbuf and transfer the bytes of the incoming
+ * packet from the interface into the pbuf.
+ *
+ */
+
+static struct pbuf *
+low_level_input(struct netif *netif)
+{
+  struct ethernetif *ethernetif = netif->state;
+  struct pbuf *p, *q;
+  u16_t len;
+
+  /* Obtain the size of the packet and put it into the "len"
+     variable. */
+  len = ;
+
+#if ETH_PAD_SIZE
+  len += ETH_PAD_SIZE;						/* allow room for Ethernet padding */
+#endif
+
+  /* We allocate a pbuf chain of pbufs from the pool. */
+  p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
+  
+  if (p != NULL) {
+
+#if ETH_PAD_SIZE
+    pbuf_header(p, -ETH_PAD_SIZE);			/* drop the padding word */
+#endif
+
+    /* We iterate over the pbuf chain until we have read the entire
+     * packet into the pbuf. */
+    for(q = p; q != NULL; q = q->next) {
+      /* Read enough bytes to fill this pbuf in the chain. The
+       * available data in the pbuf is given by the q->len
+       * variable. */
+      read data into(q->payload, q->len);
+    }
+    acknowledge that packet has been read();
+
+#if ETH_PAD_SIZE
+    pbuf_header(p, ETH_PAD_SIZE);			/* reclaim the padding word */
+#endif
+
+#if LINK_STATS
+    lwip_stats.link.recv++;
+#endif /* LINK_STATS */      
+  } else {
+    drop packet();
+#if LINK_STATS
+    lwip_stats.link.memerr++;
+    lwip_stats.link.drop++;
+#endif /* LINK_STATS */      
+  }
+
+  return p;  
+}
+
+/*
+ * ethernetif_output():
+ *
+ * This function is called by the TCP/IP stack when an IP packet
+ * should be sent. It calls the function called low_level_output() to
+ * do the actual transmission of the packet.
+ *
+ */
+
+static err_t
+ethernetif_output(struct netif *netif, struct pbuf *p,
+      struct ip_addr *ipaddr)
+{
+  
+ /* resolve hardware address, then send (or queue) packet */
+  return etharp_output(netif, ipaddr, p);
+ 
+}
+
+/*
+ * ethernetif_input():
+ *
+ * This function should be called when a packet is ready to be read
+ * from the interface. It uses the function low_level_input() that
+ * should handle the actual reception of bytes from the network
+ * interface.
+ *
+ */
+
+static void
+ethernetif_input(struct netif *netif)
+{
+  struct ethernetif *ethernetif;
+  struct eth_hdr *ethhdr;
+  struct pbuf *p;
+
+  ethernetif = netif->state;
+  
+  /* move received packet into a new pbuf */
+  p = low_level_input(netif);
+  /* no packet could be read, silently ignore this */
+  if (p == NULL) return;
+  /* points to packet payload, which starts with an Ethernet header */
+  ethhdr = p->payload;
+
+#if LINK_STATS
+  lwip_stats.link.recv++;
+#endif /* LINK_STATS */
+
+  ethhdr = p->payload;
+    
+  switch (htons(ethhdr->type)) {
+  /* IP packet? */
+  case ETHTYPE_IP:
+    /* update ARP table */
+    etharp_ip_input(netif, p);
+    /* skip Ethernet header */
+    pbuf_header(p, -sizeof(struct eth_hdr));
+    /* pass to network layer */
+    netif->input(p, netif);
+    break;
+      
+    case ETHTYPE_ARP:
+      /* pass p to ARP module  */
+      etharp_arp_input(netif, ethernetif->ethaddr, p);
+      break;
+    default:
+      pbuf_free(p);
+      p = NULL;
+      break;
+  }
+}
+
+static void
+arp_timer(void *arg)
+{
+  etharp_tmr();
+  sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
+}
+
+/*
+ * ethernetif_init():
+ *
+ * Should be called at the beginning of the program to set up the
+ * network interface. It calls the function low_level_init() to do the
+ * actual setup of the hardware.
+ *
+ */
+
+err_t
+ethernetif_init(struct netif *netif)
+{
+  struct ethernetif *ethernetif;
+    
+  ethernetif = mem_malloc(sizeof(struct ethernetif));
+  
+  if (ethernetif == NULL)
+  {
+  	LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
+  	return ERR_MEM;
+  }
+  
+  netif->state = ethernetif;
+  netif->name[0] = IFNAME0;
+  netif->name[1] = IFNAME1;
+  netif->output = ethernetif_output;
+  netif->linkoutput = low_level_output;
+  
+  ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
+  
+  low_level_init(netif);
+
+  etharp_init();
+
+  sys_timeout(ARP_TMR_INTERVAL, arp_timer, NULL);
+
+  return ERR_OK;
+}
+