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 */
69struct ethernetif {
70  struct eth_addr *ethaddr;
71  /* Add whatever per-interface state that is needed here. */
72};
73
74/* Forward declarations. */
75static 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 */
84static void
85low_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
136static err_t
137low_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 */
184static struct pbuf *
185low_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 */
255static void
256ethernetif_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 */
289err_t
290ethernetif_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 */
336