1 /** 2 * @file 3 * Ethernet Interface Skeleton 4 * 5 */ 6 7 /* 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without modification, 12 * are permitted provided that the following conditions are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright notice, 15 * this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright notice, 17 * this list of conditions and the following disclaimer in the documentation 18 * and/or other materials provided with the distribution. 19 * 3. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 31 * OF SUCH DAMAGE. 32 * 33 * This file is part of the lwIP TCP/IP stack. 34 * 35 * Author: Adam Dunkels <adam@sics.se> 36 * 37 */ 38 39 /* 40 * This file is a skeleton for developing Ethernet network interface 41 * drivers for lwIP. Add code to the low_level functions and do a 42 * search-and-replace for the word "ethernetif" to replace it with 43 * something that better describes your network interface. 44 */ 45 46 #include "lwip/opt.h" 47 48 #if 0 /* don't build, this is only a skeleton, see previous comment */ 49 50 #include "lwip/def.h" 51 #include "lwip/mem.h" 52 #include "lwip/pbuf.h" 53 #include "lwip/sys.h" 54 #include <lwip/stats.h> 55 #include <lwip/snmp.h> 56 #include "netif/etharp.h" 57 #include "netif/ppp_oe.h" 58 59 /* Define those to better describe your network interface. */ 60 #define IFNAME0 'e' 61 #define IFNAME1 'n' 62 63 /** 64 * Helper struct to hold private data used to operate your ethernet interface. 65 * Keeping the ethernet address of the MAC in this struct is not necessary 66 * as it is already kept in the struct netif. 67 * But this is only an example, anyway... 68 */ 69 struct ethernetif { 70 struct eth_addr *ethaddr; 71 /* Add whatever per-interface state that is needed here. */ 72 }; 73 74 /* Forward declarations. */ 75 static void ethernetif_input(struct netif *netif); 76 77 /** 78 * In this function, the hardware should be initialized. 79 * Called from ethernetif_init(). 80 * 81 * @param netif the already initialized lwip network interface structure 82 * for this ethernetif 83 */ 84 static void 85 low_level_init(struct netif *netif) 86 { 87 struct ethernetif *ethernetif = netif->state; 88 89 /* set MAC hardware address length */ 90 netif->hwaddr_len = ETHARP_HWADDR_LEN; 91 92 /* set MAC hardware address */ 93 netif->hwaddr[0] = ; 94 ... 95 netif->hwaddr[5] = ; 96 97 /* maximum transfer unit */ 98 netif->mtu = 1500; 99 100 /* device capabilities */ 101 /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */ 102 netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP; 103 104 /* Do whatever else is needed to initialize interface. */ 105 } 106 107 /** 108 * This function should do the actual transmission of the packet. The packet is 109 * contained in the pbuf that is passed to the function. This pbuf 110 * might be chained. 111 * 112 * @param netif the lwip network interface structure for this ethernetif 113 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type) 114 * @return ERR_OK if the packet could be sent 115 * an err_t value if the packet couldn't be sent 116 * 117 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to 118 * strange results. You might consider waiting for space in the DMA queue 119 * to become availale since the stack doesn't retry to send a packet 120 * dropped because of memory failure (except for the TCP timers). 121 */ 122 123 static err_t 124 low_level_output(struct netif *netif, struct pbuf *p) 125 { 126 struct ethernetif *ethernetif = netif->state; 127 struct pbuf *q; 128 129 initiate transfer(); 130 131 #if ETH_PAD_SIZE 132 pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */ 133 #endif 134 135 for(q = p; q != NULL; q = q->next) { 136 /* Send the data from the pbuf to the interface, one pbuf at a 137 time. The size of the data in each pbuf is kept in the ->len 138 variable. */ 139 send data from(q->payload, q->len); 140 } 141 142 signal that packet should be sent(); 143 144 #if ETH_PAD_SIZE 145 pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */ 146 #endif 147 148 LINK_STATS_INC(link.xmit); 149 150 return ERR_OK; 151 } 152 153 /** 154 * Should allocate a pbuf and transfer the bytes of the incoming 155 * packet from the interface into the pbuf. 156 * 157 * @param netif the lwip network interface structure for this ethernetif 158 * @return a pbuf filled with the received packet (including MAC header) 159 * NULL on memory error 160 */ 161 static struct pbuf * 162 low_level_input(struct netif *netif) 163 { 164 struct ethernetif *ethernetif = netif->state; 165 struct pbuf *p, *q; 166 u16_t len; 167 168 /* Obtain the size of the packet and put it into the "len" 169 variable. */ 170 len = ; 171 172 #if ETH_PAD_SIZE 173 len += ETH_PAD_SIZE; /* allow room for Ethernet padding */ 174 #endif 175 176 /* We allocate a pbuf chain of pbufs from the pool. */ 177 p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL); 178 179 if (p != NULL) { 180 181 #if ETH_PAD_SIZE 182 pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */ 183 #endif 184 185 /* We iterate over the pbuf chain until we have read the entire 186 * packet into the pbuf. */ 187 for(q = p; q != NULL; q = q->next) { 188 /* Read enough bytes to fill this pbuf in the chain. The 189 * available data in the pbuf is given by the q->len 190 * variable. */ 191 read data into(q->payload, q->len); 192 } 193 acknowledge that packet has been read(); 194 195 #if ETH_PAD_SIZE 196 pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */ 197 #endif 198 199 LINK_STATS_INC(link.recv); 200 } else { 201 drop packet(); 202 LINK_STATS_INC(link.memerr); 203 LINK_STATS_INC(link.drop); 204 } 205 206 return p; 207 } 208 209 /** 210 * This function should be called when a packet is ready to be read 211 * from the interface. It uses the function low_level_input() that 212 * should handle the actual reception of bytes from the network 213 * interface. Then the type of the received packet is determined and 214 * the appropriate input function is called. 215 * 216 * @param netif the lwip network interface structure for this ethernetif 217 */ 218 static void 219 ethernetif_input(struct netif *netif) 220 { 221 struct ethernetif *ethernetif; 222 struct eth_hdr *ethhdr; 223 struct pbuf *p; 224 225 ethernetif = netif->state; 226 227 /* move received packet into a new pbuf */ 228 p = low_level_input(netif); 229 /* no packet could be read, silently ignore this */ 230 if (p == NULL) return; 231 /* points to packet payload, which starts with an Ethernet header */ 232 ethhdr = p->payload; 233 234 switch (htons(ethhdr->type)) { 235 /* IP or ARP packet? */ 236 case ETHTYPE_IP: 237 case ETHTYPE_ARP: 238 #if PPPOE_SUPPORT 239 /* PPPoE packet? */ 240 case ETHTYPE_PPPOEDISC: 241 case ETHTYPE_PPPOE: 242 #endif /* PPPOE_SUPPORT */ 243 /* full packet send to tcpip_thread to process */ 244 if (netif->input(p, netif)!=ERR_OK) 245 { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n")); 246 pbuf_free(p); 247 p = NULL; 248 } 249 break; 250 251 default: 252 pbuf_free(p); 253 p = NULL; 254 break; 255 } 256 } 257 258 /** 259 * Should be called at the beginning of the program to set up the 260 * network interface. It calls the function low_level_init() to do the 261 * actual setup of the hardware. 262 * 263 * This function should be passed as a parameter to netif_add(). 264 * 265 * @param netif the lwip network interface structure for this ethernetif 266 * @return ERR_OK if the loopif is initialized 267 * ERR_MEM if private data couldn't be allocated 268 * any other err_t on error 269 */ 270 err_t 271 ethernetif_init(struct netif *netif) 272 { 273 struct ethernetif *ethernetif; 274 275 LWIP_ASSERT("netif != NULL", (netif != NULL)); 276 277 ethernetif = mem_malloc(sizeof(struct ethernetif)); 278 if (ethernetif == NULL) { 279 LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n")); 280 return ERR_MEM; 281 } 282 283 #if LWIP_NETIF_HOSTNAME 284 /* Initialize interface hostname */ 285 netif->hostname = "lwip"; 286 #endif /* LWIP_NETIF_HOSTNAME */ 287 288 /* 289 * Initialize the snmp variables and counters inside the struct netif. 290 * The last argument should be replaced with your link speed, in units 291 * of bits per second. 292 */ 293 NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS); 294 295 netif->state = ethernetif; 296 netif->name[0] = IFNAME0; 297 netif->name[1] = IFNAME1; 298 /* We directly use etharp_output() here to save a function call. 299 * You can instead declare your own function an call etharp_output() 300 * from it if you have to do some checks before sending (e.g. if link 301 * is available...) */ 302 netif->output = etharp_output; 303 netif->linkoutput = low_level_output; 304 305 ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]); 306 307 /* initialize the hardware */ 308 low_level_init(netif); 309 310 return ERR_OK; 311 } 312 313 #endif /* 0 */ 314