minix/lib/liblwip/netif/ethernetif.c

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/**
* @file
* Ethernet Interface Skeleton
*
*/
/*
* 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"
#if 0 /* don't build, this is only a skeleton, see previous comment */
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#include <lwip/stats.h>
#include <lwip/snmp.h>
#include "netif/etharp.h"
#include "netif/ppp_oe.h"
/* Define those to better describe your network interface. */
#define IFNAME0 'e'
#define IFNAME1 'n'
/**
* Helper struct to hold private data used to operate your ethernet interface.
* Keeping the ethernet address of the MAC in this struct is not necessary
* as it is already kept in the struct netif.
* But this is only an example, anyway...
*/
struct ethernetif {
struct eth_addr *ethaddr;
/* Add whatever per-interface state that is needed here. */
};
/* Forward declarations. */
static void ethernetif_input(struct netif *netif);
/**
* In this function, the hardware should be initialized.
* Called from ethernetif_init().
*
* @param netif the already initialized lwip network interface structure
* for this ethernetif
*/
static void
low_level_init(struct netif *netif)
{
struct ethernetif *ethernetif = netif->state;
/* set MAC hardware address length */
netif->hwaddr_len = ETHARP_HWADDR_LEN;
/* set MAC hardware address */
netif->hwaddr[0] = ;
...
netif->hwaddr[5] = ;
/* maximum transfer unit */
netif->mtu = 1500;
/* device capabilities */
/* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
/* Do whatever else is needed to initialize interface. */
}
/**
* This function 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.
*
* @param netif the lwip network interface structure for this ethernetif
* @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
* @return ERR_OK if the packet could be sent
* an err_t value if the packet couldn't be sent
*
* @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
* strange results. You might consider waiting for space in the DMA queue
* to become availale since the stack doesn't retry to send a packet
* dropped because of memory failure (except for the TCP timers).
*/
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
LINK_STATS_INC(link.xmit);
return ERR_OK;
}
/**
* Should allocate a pbuf and transfer the bytes of the incoming
* packet from the interface into the pbuf.
*
* @param netif the lwip network interface structure for this ethernetif
* @return a pbuf filled with the received packet (including MAC header)
* NULL on memory error
*/
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.
* This does not necessarily have to be a memcpy, you can also preallocate
* pbufs for a DMA-enabled MAC and after receiving truncate it to the
* actually received size. In this case, ensure the tot_len member of the
* pbuf is the sum of the chained pbuf len members.
*/
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
LINK_STATS_INC(link.recv);
} else {
drop packet();
LINK_STATS_INC(link.memerr);
LINK_STATS_INC(link.drop);
}
return p;
}
/**
* 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. Then the type of the received packet is determined and
* the appropriate input function is called.
*
* @param netif the lwip network interface structure for this ethernetif
*/
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;
switch (htons(ethhdr->type)) {
/* IP or ARP packet? */
case ETHTYPE_IP:
case ETHTYPE_ARP:
#if PPPOE_SUPPORT
/* PPPoE packet? */
case ETHTYPE_PPPOEDISC:
case ETHTYPE_PPPOE:
#endif /* PPPOE_SUPPORT */
/* full packet send to tcpip_thread to process */
if (netif->input(p, netif)!=ERR_OK)
{ LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
pbuf_free(p);
p = NULL;
}
break;
default:
pbuf_free(p);
p = NULL;
break;
}
}
/**
* 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.
*
* This function should be passed as a parameter to netif_add().
*
* @param netif the lwip network interface structure for this ethernetif
* @return ERR_OK if the loopif is initialized
* ERR_MEM if private data couldn't be allocated
* any other err_t on error
*/
err_t
ethernetif_init(struct netif *netif)
{
struct ethernetif *ethernetif;
LWIP_ASSERT("netif != NULL", (netif != NULL));
ethernetif = mem_malloc(sizeof(struct ethernetif));
if (ethernetif == NULL) {
LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
return ERR_MEM;
}
#if LWIP_NETIF_HOSTNAME
/* Initialize interface hostname */
netif->hostname = "lwip";
#endif /* LWIP_NETIF_HOSTNAME */
/*
* Initialize the snmp variables and counters inside the struct netif.
* The last argument should be replaced with your link speed, in units
* of bits per second.
*/
NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS);
netif->state = ethernetif;
netif->name[0] = IFNAME0;
netif->name[1] = IFNAME1;
/* We directly use etharp_output() here to save a function call.
* You can instead declare your own function an call etharp_output()
* from it if you have to do some checks before sending (e.g. if link
* is available...) */
netif->output = etharp_output;
netif->linkoutput = low_level_output;
ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
/* initialize the hardware */
low_level_init(netif);
return ERR_OK;
}
#endif /* 0 */