minix/lib/liblwip/dist/src/netif/ethernetif.c

   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/stats.h"
  54 #include "lwip/snmp.h"
  55 #include "lwip/ethip6.h"
  56 #include "lwip/etharp.h"
  57 #include "netif/ppp/pppoe.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 #if LWIP_IPV6 && LWIP_IPV6_MLD
 105   /*
 106    * For hardware/netifs that implement MAC filtering.
 107    * All-nodes link-local is handled by default, so we must let the hardware know
 108    * to allow multicast packets in.
 109    * Should set mld_mac_filter previously. */
 110   if (netif->mld_mac_filter != NULL) {
 111     ip6_addr_t ip6_allnodes_ll;
 112     ip6_addr_set_allnodes_linklocal(&ip6_allnodes_ll);
 113     netif->mld_mac_filter(netif, &ip6_allnodes_ll, NETIF_ADD_MAC_FILTER);
 114   }
 115 #endif /* LWIP_IPV6 && LWIP_IPV6_MLD */
 116
 117   /* Do whatever else is needed to initialize interface. */
 118 }
 119
 120 /**
 121  * This function should do the actual transmission of the packet. The packet is
 122  * contained in the pbuf that is passed to the function. This pbuf
 123  * might be chained.
 124  *
 125  * @param netif the lwip network interface structure for this ethernetif
 126  * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
 127  * @return ERR_OK if the packet could be sent
 128  *         an err_t value if the packet couldn't be sent
 129  *
 130  * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
 131  *       strange results. You might consider waiting for space in the DMA queue
 132  *       to become available since the stack doesn't retry to send a packet
 133  *       dropped because of memory failure (except for the TCP timers).
 134  */
 135
 136 static err_t
 137 low_level_output(struct netif *netif, struct pbuf *p)
 138 {
 139   struct ethernetif *ethernetif = netif->state;
 140   struct pbuf *q;
 141
 142   initiate transfer();
 143
 144 #if ETH_PAD_SIZE
 145   pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
 146 #endif
 147
 148   for (q = p; q != NULL; q = q->next) {
 149     /* Send the data from the pbuf to the interface, one pbuf at a
 150        time. The size of the data in each pbuf is kept in the ->len
 151        variable. */
 152     send data from(q->payload, q->len);
 153   }
 154
 155   signal that packet should be sent();
 156
 157   MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p->tot_len);
 158   if (((u8_t*)p->payload)[0] & 1) {
 159     /* broadcast or multicast packet*/
 160     MIB2_STATS_NETIF_INC(netif, ifoutnucastpkts);
 161   } else {
 162     /* unicast packet */
 163     MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
 164   }
 165   /* increase ifoutdiscards or ifouterrors on error */
 166
 167 #if ETH_PAD_SIZE
 168   pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
 169 #endif
 170
 171   LINK_STATS_INC(link.xmit);
 172
 173   return ERR_OK;
 174 }
 175
 176 /**
 177  * Should allocate a pbuf and transfer the bytes of the incoming
 178  * packet from the interface into the pbuf.
 179  *
 180  * @param netif the lwip network interface structure for this ethernetif
 181  * @return a pbuf filled with the received packet (including MAC header)
 182  *         NULL on memory error
 183  */
 184 static struct pbuf *
 185 low_level_input(struct netif *netif)
 186 {
 187   struct ethernetif *ethernetif = netif->state;
 188   struct pbuf *p, *q;
 189   u16_t len;
 190
 191   /* Obtain the size of the packet and put it into the "len"
 192      variable. */
 193   len = ;
 194
 195 #if ETH_PAD_SIZE
 196   len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
 197 #endif
 198
 199   /* We allocate a pbuf chain of pbufs from the pool. */
 200   p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
 201
 202   if (p != NULL) {
 203
 204 #if ETH_PAD_SIZE
 205     pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
 206 #endif
 207
 208     /* We iterate over the pbuf chain until we have read the entire
 209      * packet into the pbuf. */
 210     for (q = p; q != NULL; q = q->next) {
 211       /* Read enough bytes to fill this pbuf in the chain. The
 212        * available data in the pbuf is given by the q->len
 213        * variable.
 214        * This does not necessarily have to be a memcpy, you can also preallocate
 215        * pbufs for a DMA-enabled MAC and after receiving truncate it to the
 216        * actually received size. In this case, ensure the tot_len member of the
 217        * pbuf is the sum of the chained pbuf len members.
 218        */
 219       read data into(q->payload, q->len);
 220     }
 221     acknowledge that packet has been read();
 222
 223     MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len);
 224     if (((u8_t*)p->payload)[0] & 1) {
 225       /* broadcast or multicast packet*/
 226       MIB2_STATS_NETIF_INC(netif, ifinnucastpkts);
 227     } else {
 228       /* unicast packet*/
 229       MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
 230     }
 231 #if ETH_PAD_SIZE
 232     pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
 233 #endif
 234
 235     LINK_STATS_INC(link.recv);
 236   } else {
 237     drop packet();
 238     LINK_STATS_INC(link.memerr);
 239     LINK_STATS_INC(link.drop);
 240     MIB2_STATS_NETIF_INC(netif, ifindiscards);
 241   }
 242
 243   return p;
 244 }
 245
 246 /**
 247  * This function should be called when a packet is ready to be read
 248  * from the interface. It uses the function low_level_input() that
 249  * should handle the actual reception of bytes from the network
 250  * interface. Then the type of the received packet is determined and
 251  * the appropriate input function is called.
 252  *
 253  * @param netif the lwip network interface structure for this ethernetif
 254  */
 255 static void
 256 ethernetif_input(struct netif *netif)
 257 {
 258   struct ethernetif *ethernetif;
 259   struct eth_hdr *ethhdr;
 260   struct pbuf *p;
 261
 262   ethernetif = netif->state;
 263
 264   /* move received packet into a new pbuf */
 265   p = low_level_input(netif);
 266   /* if no packet could be read, silently ignore this */
 267   if (p != NULL) {
 268     /* pass all packets to ethernet_input, which decides what packets it supports */
 269     if (netif->input(p, netif) != ERR_OK) {
 270       LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
 271       pbuf_free(p);
 272       p = NULL;
 273     }
 274   }
 275 }
 276
 277 /**
 278  * Should be called at the beginning of the program to set up the
 279  * network interface. It calls the function low_level_init() to do the
 280  * actual setup of the hardware.
 281  *
 282  * This function should be passed as a parameter to netif_add().
 283  *
 284  * @param netif the lwip network interface structure for this ethernetif
 285  * @return ERR_OK if the loopif is initialized
 286  *         ERR_MEM if private data couldn't be allocated
 287  *         any other err_t on error
 288  */
 289 err_t
 290 ethernetif_init(struct netif *netif)
 291 {
 292   struct ethernetif *ethernetif;
 293
 294   LWIP_ASSERT("netif != NULL", (netif != NULL));
 295
 296   ethernetif = mem_malloc(sizeof(struct ethernetif));
 297   if (ethernetif == NULL) {
 298     LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
 299     return ERR_MEM;
 300   }
 301
 302 #if LWIP_NETIF_HOSTNAME
 303   /* Initialize interface hostname */
 304   netif->hostname = "lwip";
 305 #endif /* LWIP_NETIF_HOSTNAME */
 306
 307   /*
 308    * Initialize the snmp variables and counters inside the struct netif.
 309    * The last argument should be replaced with your link speed, in units
 310    * of bits per second.
 311    */
 312   MIB2_INIT_NETIF(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS);
 313
 314   netif->state = ethernetif;
 315   netif->name[0] = IFNAME0;
 316   netif->name[1] = IFNAME1;
 317   /* We directly use etharp_output() here to save a function call.
 318    * You can instead declare your own function an call etharp_output()
 319    * from it if you have to do some checks before sending (e.g. if link
 320    * is available...) */
 321   netif->output = etharp_output;
 322 #if LWIP_IPV6
 323   netif->output_ip6 = ethip6_output;
 324 #endif /* LWIP_IPV6 */
 325   netif->linkoutput = low_level_output;
 326
 327   ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
 328
 329   /* initialize the hardware */
 330   low_level_init(netif);
 331
 332   return ERR_OK;
 333 }
 334
 335 #endif /* 0 */