source: UsbWattMeter/trunk/lwip-1.4.1/src/netif/ethernetif.c@ 164

Last change on this file since 164 was 164, checked in by coas-nagasima, 6 years ago

TOPPERS/ECNLサンプルアプリ「USB充電器電力計」を追加

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File size: 9.5 KB
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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 "netif/etharp.h"
56#include "netif/ppp_oe.h"
57
58/* Define those to better describe your network interface. */
59#define IFNAME0 'e'
60#define IFNAME1 'n'
61
62/**
63 * Helper struct to hold private data used to operate your ethernet interface.
64 * Keeping the ethernet address of the MAC in this struct is not necessary
65 * as it is already kept in the struct netif.
66 * But this is only an example, anyway...
67 */
68struct ethernetif {
69 struct eth_addr *ethaddr;
70 /* Add whatever per-interface state that is needed here. */
71};
72
73/* Forward declarations. */
74static void ethernetif_input(struct netif *netif);
75
76/**
77 * In this function, the hardware should be initialized.
78 * Called from ethernetif_init().
79 *
80 * @param netif the already initialized lwip network interface structure
81 * for this ethernetif
82 */
83static void
84low_level_init(struct netif *netif)
85{
86 struct ethernetif *ethernetif = netif->state;
87
88 /* set MAC hardware address length */
89 netif->hwaddr_len = ETHARP_HWADDR_LEN;
90
91 /* set MAC hardware address */
92 netif->hwaddr[0] = ;
93 ...
94 netif->hwaddr[5] = ;
95
96 /* maximum transfer unit */
97 netif->mtu = 1500;
98
99 /* device capabilities */
100 /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
101 netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
102
103 /* Do whatever else is needed to initialize interface. */
104}
105
106/**
107 * This function should do the actual transmission of the packet. The packet is
108 * contained in the pbuf that is passed to the function. This pbuf
109 * might be chained.
110 *
111 * @param netif the lwip network interface structure for this ethernetif
112 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
113 * @return ERR_OK if the packet could be sent
114 * an err_t value if the packet couldn't be sent
115 *
116 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
117 * strange results. You might consider waiting for space in the DMA queue
118 * to become availale since the stack doesn't retry to send a packet
119 * dropped because of memory failure (except for the TCP timers).
120 */
121
122static err_t
123low_level_output(struct netif *netif, struct pbuf *p)
124{
125 struct ethernetif *ethernetif = netif->state;
126 struct pbuf *q;
127
128 initiate transfer();
129
130#if ETH_PAD_SIZE
131 pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
132#endif
133
134 for(q = p; q != NULL; q = q->next) {
135 /* Send the data from the pbuf to the interface, one pbuf at a
136 time. The size of the data in each pbuf is kept in the ->len
137 variable. */
138 send data from(q->payload, q->len);
139 }
140
141 signal that packet should be sent();
142
143#if ETH_PAD_SIZE
144 pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
145#endif
146
147 LINK_STATS_INC(link.xmit);
148
149 return ERR_OK;
150}
151
152/**
153 * Should allocate a pbuf and transfer the bytes of the incoming
154 * packet from the interface into the pbuf.
155 *
156 * @param netif the lwip network interface structure for this ethernetif
157 * @return a pbuf filled with the received packet (including MAC header)
158 * NULL on memory error
159 */
160static struct pbuf *
161low_level_input(struct netif *netif)
162{
163 struct ethernetif *ethernetif = netif->state;
164 struct pbuf *p, *q;
165 u16_t len;
166
167 /* Obtain the size of the packet and put it into the "len"
168 variable. */
169 len = ;
170
171#if ETH_PAD_SIZE
172 len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
173#endif
174
175 /* We allocate a pbuf chain of pbufs from the pool. */
176 p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
177
178 if (p != NULL) {
179
180#if ETH_PAD_SIZE
181 pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
182#endif
183
184 /* We iterate over the pbuf chain until we have read the entire
185 * packet into the pbuf. */
186 for(q = p; q != NULL; q = q->next) {
187 /* Read enough bytes to fill this pbuf in the chain. The
188 * available data in the pbuf is given by the q->len
189 * variable.
190 * This does not necessarily have to be a memcpy, you can also preallocate
191 * pbufs for a DMA-enabled MAC and after receiving truncate it to the
192 * actually received size. In this case, ensure the tot_len member of the
193 * pbuf is the sum of the chained pbuf len members.
194 */
195 read data into(q->payload, q->len);
196 }
197 acknowledge that packet has been read();
198
199#if ETH_PAD_SIZE
200 pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
201#endif
202
203 LINK_STATS_INC(link.recv);
204 } else {
205 drop packet();
206 LINK_STATS_INC(link.memerr);
207 LINK_STATS_INC(link.drop);
208 }
209
210 return p;
211}
212
213/**
214 * This function should be called when a packet is ready to be read
215 * from the interface. It uses the function low_level_input() that
216 * should handle the actual reception of bytes from the network
217 * interface. Then the type of the received packet is determined and
218 * the appropriate input function is called.
219 *
220 * @param netif the lwip network interface structure for this ethernetif
221 */
222static void
223ethernetif_input(struct netif *netif)
224{
225 struct ethernetif *ethernetif;
226 struct eth_hdr *ethhdr;
227 struct pbuf *p;
228
229 ethernetif = netif->state;
230
231 /* move received packet into a new pbuf */
232 p = low_level_input(netif);
233 /* no packet could be read, silently ignore this */
234 if (p == NULL) return;
235 /* points to packet payload, which starts with an Ethernet header */
236 ethhdr = p->payload;
237
238 switch (htons(ethhdr->type)) {
239 /* IP or ARP packet? */
240 case ETHTYPE_IP:
241 case ETHTYPE_ARP:
242#if PPPOE_SUPPORT
243 /* PPPoE packet? */
244 case ETHTYPE_PPPOEDISC:
245 case ETHTYPE_PPPOE:
246#endif /* PPPOE_SUPPORT */
247 /* full packet send to tcpip_thread to process */
248 if (netif->input(p, netif)!=ERR_OK)
249 { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
250 pbuf_free(p);
251 p = NULL;
252 }
253 break;
254
255 default:
256 pbuf_free(p);
257 p = NULL;
258 break;
259 }
260}
261
262/**
263 * Should be called at the beginning of the program to set up the
264 * network interface. It calls the function low_level_init() to do the
265 * actual setup of the hardware.
266 *
267 * This function should be passed as a parameter to netif_add().
268 *
269 * @param netif the lwip network interface structure for this ethernetif
270 * @return ERR_OK if the loopif is initialized
271 * ERR_MEM if private data couldn't be allocated
272 * any other err_t on error
273 */
274err_t
275ethernetif_init(struct netif *netif)
276{
277 struct ethernetif *ethernetif;
278
279 LWIP_ASSERT("netif != NULL", (netif != NULL));
280
281 ethernetif = mem_malloc(sizeof(struct ethernetif));
282 if (ethernetif == NULL) {
283 LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
284 return ERR_MEM;
285 }
286
287#if LWIP_NETIF_HOSTNAME
288 /* Initialize interface hostname */
289 netif->hostname = "lwip";
290#endif /* LWIP_NETIF_HOSTNAME */
291
292 /*
293 * Initialize the snmp variables and counters inside the struct netif.
294 * The last argument should be replaced with your link speed, in units
295 * of bits per second.
296 */
297 NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS);
298
299 netif->state = ethernetif;
300 netif->name[0] = IFNAME0;
301 netif->name[1] = IFNAME1;
302 /* We directly use etharp_output() here to save a function call.
303 * You can instead declare your own function an call etharp_output()
304 * from it if you have to do some checks before sending (e.g. if link
305 * is available...) */
306 netif->output = etharp_output;
307 netif->linkoutput = low_level_output;
308
309 ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
310
311 /* initialize the hardware */
312 low_level_init(netif);
313
314 return ERR_OK;
315}
316
317#endif /* 0 */
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