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Diff: netif/ethernetif.c
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- 0:51ac1d130fd4
diff -r 000000000000 -r 51ac1d130fd4 netif/ethernetif.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/netif/ethernetif.c Fri Jun 22 09:25:39 2012 +0000 @@ -0,0 +1,318 @@ +/** + * @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 */