xref: /minix/minix/lib/liblwip/dist/src/netif/ethernet.c (revision bb9622b5)
1 /**
2  * @file
3  * Ethernet common functions
4  *
5  * @defgroup ethernet Ethernet
6  * @ingroup callbackstyle_api
7  */
8 
9 /*
10  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
11  * Copyright (c) 2003-2004 Leon Woestenberg <leon.woestenberg@axon.tv>
12  * Copyright (c) 2003-2004 Axon Digital Design B.V., The Netherlands.
13  * All rights reserved.
14  *
15  * Redistribution and use in source and binary forms, with or without modification,
16  * are permitted provided that the following conditions are met:
17  *
18  * 1. Redistributions of source code must retain the above copyright notice,
19  *    this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright notice,
21  *    this list of conditions and the following disclaimer in the documentation
22  *    and/or other materials provided with the distribution.
23  * 3. The name of the author may not be used to endorse or promote products
24  *    derived from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
27  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
28  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
29  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
31  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
34  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * This file is part of the lwIP TCP/IP stack.
38  *
39  */
40 
41 #include "lwip/opt.h"
42 
43 #if LWIP_ARP || LWIP_ETHERNET
44 
45 #include "netif/ethernet.h"
46 #include "lwip/def.h"
47 #include "lwip/stats.h"
48 #include "lwip/etharp.h"
49 #include "lwip/ip.h"
50 #include "lwip/snmp.h"
51 
52 #include <string.h>
53 
54 #include "netif/ppp/ppp_opts.h"
55 #if PPPOE_SUPPORT
56 #include "netif/ppp/pppoe.h"
57 #endif /* PPPOE_SUPPORT */
58 
59 #ifdef LWIP_HOOK_FILENAME
60 #include LWIP_HOOK_FILENAME
61 #endif
62 
63 const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
64 const struct eth_addr ethzero = {{0,0,0,0,0,0}};
65 
66 /**
67  * @ingroup lwip_nosys
68  * Process received ethernet frames. Using this function instead of directly
69  * calling ip_input and passing ARP frames through etharp in ethernetif_input,
70  * the ARP cache is protected from concurrent access.\n
71  * Don't call directly, pass to netif_add() and call netif->input().
72  *
73  * @param p the received packet, p->payload pointing to the ethernet header
74  * @param netif the network interface on which the packet was received
75  *
76  * @see LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
77  * @see ETHARP_SUPPORT_VLAN
78  * @see LWIP_HOOK_VLAN_CHECK
79  */
80 err_t
81 ethernet_input(struct pbuf *p, struct netif *netif)
82 {
83   struct eth_hdr* ethhdr;
84   u16_t type;
85 #if LWIP_ARP || ETHARP_SUPPORT_VLAN || LWIP_IPV6
86   s16_t ip_hdr_offset = SIZEOF_ETH_HDR;
87 #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */
88 
89   if (p->len <= SIZEOF_ETH_HDR) {
90     /* a packet with only an ethernet header (or less) is not valid for us */
91     ETHARP_STATS_INC(etharp.proterr);
92     ETHARP_STATS_INC(etharp.drop);
93     MIB2_STATS_NETIF_INC(netif, ifinerrors);
94     goto free_and_return;
95   }
96 
97   if (p->if_idx == NETIF_NO_INDEX) {
98     p->if_idx = netif_get_index(netif);
99   }
100 
101   /* points to packet payload, which starts with an Ethernet header */
102   ethhdr = (struct eth_hdr *)p->payload;
103   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
104     ("ethernet_input: dest:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", src:%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F":%"X8_F", type:%"X16_F"\n",
105      (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
106      (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
107      (unsigned)ethhdr->src.addr[0],  (unsigned)ethhdr->src.addr[1],  (unsigned)ethhdr->src.addr[2],
108      (unsigned)ethhdr->src.addr[3],  (unsigned)ethhdr->src.addr[4],  (unsigned)ethhdr->src.addr[5],
109      lwip_htons(ethhdr->type)));
110 
111   type = ethhdr->type;
112 #if ETHARP_SUPPORT_VLAN
113   if (type == PP_HTONS(ETHTYPE_VLAN)) {
114     struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR);
115     if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) {
116       /* a packet with only an ethernet/vlan header (or less) is not valid for us */
117       ETHARP_STATS_INC(etharp.proterr);
118       ETHARP_STATS_INC(etharp.drop);
119       MIB2_STATS_NETIF_INC(netif, ifinerrors);
120       goto free_and_return;
121     }
122 #if defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */
123 #ifdef LWIP_HOOK_VLAN_CHECK
124     if (!LWIP_HOOK_VLAN_CHECK(netif, ethhdr, vlan)) {
125 #elif defined(ETHARP_VLAN_CHECK_FN)
126     if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) {
127 #elif defined(ETHARP_VLAN_CHECK)
128     if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
129 #endif
130       /* silently ignore this packet: not for our VLAN */
131       pbuf_free(p);
132       return ERR_OK;
133     }
134 #endif /* defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */
135     type = vlan->tpid;
136     ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR;
137   }
138 #endif /* ETHARP_SUPPORT_VLAN */
139 
140 #if LWIP_ARP_FILTER_NETIF
141   netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, lwip_htons(type));
142 #endif /* LWIP_ARP_FILTER_NETIF*/
143 
144   if (ethhdr->dest.addr[0] & 1) {
145     /* this might be a multicast or broadcast packet */
146     if (ethhdr->dest.addr[0] == LL_IP4_MULTICAST_ADDR_0) {
147 #if LWIP_IPV4
148       if ((ethhdr->dest.addr[1] == LL_IP4_MULTICAST_ADDR_1) &&
149           (ethhdr->dest.addr[2] == LL_IP4_MULTICAST_ADDR_2)) {
150         /* mark the pbuf as link-layer multicast */
151         p->flags |= PBUF_FLAG_LLMCAST;
152       }
153 #endif /* LWIP_IPV4 */
154     }
155 #if LWIP_IPV6
156     else if ((ethhdr->dest.addr[0] == LL_IP6_MULTICAST_ADDR_0) &&
157              (ethhdr->dest.addr[1] == LL_IP6_MULTICAST_ADDR_1)) {
158         /* mark the pbuf as link-layer multicast */
159         p->flags |= PBUF_FLAG_LLMCAST;
160     }
161 #endif /* LWIP_IPV6 */
162     else if (eth_addr_cmp(&ethhdr->dest, &ethbroadcast)) {
163       /* mark the pbuf as link-layer broadcast */
164       p->flags |= PBUF_FLAG_LLBCAST;
165     }
166   }
167 
168   switch (type) {
169 #if LWIP_IPV4 && LWIP_ARP
170     /* IP packet? */
171     case PP_HTONS(ETHTYPE_IP):
172       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
173         goto free_and_return;
174       }
175       /* skip Ethernet header */
176       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
177         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
178           ("ethernet_input: IPv4 packet dropped, too short (%"S16_F"/%"S16_F")\n",
179           p->tot_len, ip_hdr_offset));
180         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
181         goto free_and_return;
182       } else {
183         /* pass to IP layer */
184         ip4_input(p, netif);
185       }
186       break;
187 
188     case PP_HTONS(ETHTYPE_ARP):
189       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
190         goto free_and_return;
191       }
192       /* skip Ethernet header */
193       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
194         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
195           ("ethernet_input: ARP response packet dropped, too short (%"S16_F"/%"S16_F")\n",
196           p->tot_len, ip_hdr_offset));
197         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
198         ETHARP_STATS_INC(etharp.lenerr);
199         ETHARP_STATS_INC(etharp.drop);
200         goto free_and_return;
201       } else {
202         /* pass p to ARP module */
203         etharp_input(p, netif);
204       }
205       break;
206 #endif /* LWIP_IPV4 && LWIP_ARP */
207 #if PPPOE_SUPPORT
208     case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
209       pppoe_disc_input(netif, p);
210       break;
211 
212     case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
213       pppoe_data_input(netif, p);
214       break;
215 #endif /* PPPOE_SUPPORT */
216 
217 #if LWIP_IPV6
218     case PP_HTONS(ETHTYPE_IPV6): /* IPv6 */
219       /* skip Ethernet header */
220       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
221         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
222           ("ethernet_input: IPv6 packet dropped, too short (%"S16_F"/%"S16_F")\n",
223           p->tot_len, ip_hdr_offset));
224         goto free_and_return;
225       } else {
226         /* pass to IPv6 layer */
227         ip6_input(p, netif);
228       }
229       break;
230 #endif /* LWIP_IPV6 */
231 
232     default:
233 #ifdef LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
234       if(LWIP_HOOK_UNKNOWN_ETH_PROTOCOL(p, netif) == ERR_OK) {
235         break;
236       }
237 #endif
238       ETHARP_STATS_INC(etharp.proterr);
239       ETHARP_STATS_INC(etharp.drop);
240       MIB2_STATS_NETIF_INC(netif, ifinunknownprotos);
241       goto free_and_return;
242   }
243 
244   /* This means the pbuf is freed or consumed,
245      so the caller doesn't have to free it again */
246   return ERR_OK;
247 
248 free_and_return:
249   pbuf_free(p);
250   return ERR_OK;
251 }
252 
253 /**
254  * @ingroup ethernet
255  * Send an ethernet packet on the network using netif->linkoutput().
256  * The ethernet header is filled in before sending.
257  *
258  * @see LWIP_HOOK_VLAN_SET
259  *
260  * @param netif the lwIP network interface on which to send the packet
261  * @param p the packet to send. pbuf layer must be @ref PBUF_LINK.
262  * @param src the source MAC address to be copied into the ethernet header
263  * @param dst the destination MAC address to be copied into the ethernet header
264  * @param eth_type ethernet type (@ref eth_type)
265  * @return ERR_OK if the packet was sent, any other err_t on failure
266  */
267 err_t
268 ethernet_output(struct netif* netif, struct pbuf* p,
269                 const struct eth_addr* src, const struct eth_addr* dst,
270                 u16_t eth_type)
271 {
272   struct eth_hdr* ethhdr;
273   u16_t eth_type_be = lwip_htons(eth_type);
274 
275 #if ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET)
276   s32_t vlan_prio_vid = LWIP_HOOK_VLAN_SET(netif, p, src, dst, eth_type);
277   if (vlan_prio_vid >= 0) {
278     struct eth_vlan_hdr* vlanhdr;
279 
280     LWIP_ASSERT("prio_vid must be <= 0xFFFF", vlan_prio_vid <= 0xFFFF);
281 
282     if (pbuf_header(p, SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) != 0) {
283       goto pbuf_header_failed;
284     }
285     vlanhdr = (struct eth_vlan_hdr*)(((u8_t*)p->payload) + SIZEOF_ETH_HDR);
286     vlanhdr->tpid     = eth_type_be;
287     vlanhdr->prio_vid = lwip_htons((u16_t)vlan_prio_vid);
288 
289     eth_type_be = PP_HTONS(ETHTYPE_VLAN);
290   } else
291 #endif /* ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET) */
292   {
293     if (pbuf_header(p, SIZEOF_ETH_HDR) != 0) {
294       goto pbuf_header_failed;
295     }
296   }
297 
298   ethhdr = (struct eth_hdr*)p->payload;
299   ethhdr->type = eth_type_be;
300   ETHADDR16_COPY(&ethhdr->dest, dst);
301   ETHADDR16_COPY(&ethhdr->src,  src);
302 
303   LWIP_ASSERT("netif->hwaddr_len must be 6 for ethernet_output!",
304     (netif->hwaddr_len == ETH_HWADDR_LEN));
305   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
306     ("ethernet_output: sending packet %p\n", (void *)p));
307 
308   /* send the packet */
309   return netif->linkoutput(netif, p);
310 
311 pbuf_header_failed:
312   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
313     ("ethernet_output: could not allocate room for header.\n"));
314   LINK_STATS_INC(link.lenerr);
315   return ERR_BUF;
316 }
317 
318 #endif /* LWIP_ARP || LWIP_ETHERNET */
319