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 const struct eth_addr ethbroadcast = {{0xff,0xff,0xff,0xff,0xff,0xff}};
60 const struct eth_addr ethzero = {{0,0,0,0,0,0}};
61 
62 /**
63  * @ingroup lwip_nosys
64  * Process received ethernet frames. Using this function instead of directly
65  * calling ip_input and passing ARP frames through etharp in ethernetif_input,
66  * the ARP cache is protected from concurrent access.\n
67  * Don't call directly, pass to netif_add() and call netif->input().
68  *
69  * @param p the received packet, p->payload pointing to the ethernet header
70  * @param netif the network interface on which the packet was received
71  *
72  * @see LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
73  * @see ETHARP_SUPPORT_VLAN
74  * @see LWIP_HOOK_VLAN_CHECK
75  */
76 err_t
ethernet_input(struct pbuf * p,struct netif * netif)77 ethernet_input(struct pbuf *p, struct netif *netif)
78 {
79   struct eth_hdr* ethhdr;
80   u16_t type;
81 #if LWIP_ARP || ETHARP_SUPPORT_VLAN || LWIP_IPV6
82   s16_t ip_hdr_offset = SIZEOF_ETH_HDR;
83 #endif /* LWIP_ARP || ETHARP_SUPPORT_VLAN */
84 
85   if (p->len <= SIZEOF_ETH_HDR) {
86     /* a packet with only an ethernet header (or less) is not valid for us */
87     ETHARP_STATS_INC(etharp.proterr);
88     ETHARP_STATS_INC(etharp.drop);
89     MIB2_STATS_NETIF_INC(netif, ifinerrors);
90     goto free_and_return;
91   }
92 
93   /* points to packet payload, which starts with an Ethernet header */
94   ethhdr = (struct eth_hdr *)p->payload;
95   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
96     ("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",
97      (unsigned)ethhdr->dest.addr[0], (unsigned)ethhdr->dest.addr[1], (unsigned)ethhdr->dest.addr[2],
98      (unsigned)ethhdr->dest.addr[3], (unsigned)ethhdr->dest.addr[4], (unsigned)ethhdr->dest.addr[5],
99      (unsigned)ethhdr->src.addr[0],  (unsigned)ethhdr->src.addr[1],  (unsigned)ethhdr->src.addr[2],
100      (unsigned)ethhdr->src.addr[3],  (unsigned)ethhdr->src.addr[4],  (unsigned)ethhdr->src.addr[5],
101      lwip_htons(ethhdr->type)));
102 
103   type = ethhdr->type;
104 #if ETHARP_SUPPORT_VLAN
105   if (type == PP_HTONS(ETHTYPE_VLAN)) {
106     struct eth_vlan_hdr *vlan = (struct eth_vlan_hdr*)(((char*)ethhdr) + SIZEOF_ETH_HDR);
107     if (p->len <= SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) {
108       /* a packet with only an ethernet/vlan header (or less) is not valid for us */
109       ETHARP_STATS_INC(etharp.proterr);
110       ETHARP_STATS_INC(etharp.drop);
111       MIB2_STATS_NETIF_INC(netif, ifinerrors);
112       goto free_and_return;
113     }
114 #if defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) /* if not, allow all VLANs */
115 #ifdef LWIP_HOOK_VLAN_CHECK
116     if (!LWIP_HOOK_VLAN_CHECK(netif, ethhdr, vlan)) {
117 #elif defined(ETHARP_VLAN_CHECK_FN)
118     if (!ETHARP_VLAN_CHECK_FN(ethhdr, vlan)) {
119 #elif defined(ETHARP_VLAN_CHECK)
120     if (VLAN_ID(vlan) != ETHARP_VLAN_CHECK) {
121 #endif
122       /* silently ignore this packet: not for our VLAN */
123       pbuf_free(p);
124       return ERR_OK;
125     }
126 #endif /* defined(LWIP_HOOK_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK) || defined(ETHARP_VLAN_CHECK_FN) */
127     type = vlan->tpid;
128     ip_hdr_offset = SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR;
129   }
130 #endif /* ETHARP_SUPPORT_VLAN */
131 
132 #if LWIP_ARP_FILTER_NETIF
133   netif = LWIP_ARP_FILTER_NETIF_FN(p, netif, lwip_htons(type));
134 #endif /* LWIP_ARP_FILTER_NETIF*/
135 
136   if (ethhdr->dest.addr[0] & 1) {
137     /* this might be a multicast or broadcast packet */
138     if (ethhdr->dest.addr[0] == LL_IP4_MULTICAST_ADDR_0) {
139 #if LWIP_IPV4
140       if ((ethhdr->dest.addr[1] == LL_IP4_MULTICAST_ADDR_1) &&
141           (ethhdr->dest.addr[2] == LL_IP4_MULTICAST_ADDR_2)) {
142         /* mark the pbuf as link-layer multicast */
143         p->flags |= PBUF_FLAG_LLMCAST;
144       }
145 #endif /* LWIP_IPV4 */
146     }
147 #if LWIP_IPV6
148     else if ((ethhdr->dest.addr[0] == LL_IP6_MULTICAST_ADDR_0) &&
149              (ethhdr->dest.addr[1] == LL_IP6_MULTICAST_ADDR_1)) {
150         /* mark the pbuf as link-layer multicast */
151         p->flags |= PBUF_FLAG_LLMCAST;
152     }
153 #endif /* LWIP_IPV6 */
154     else if (eth_addr_cmp(&ethhdr->dest, &ethbroadcast)) {
155       /* mark the pbuf as link-layer broadcast */
156       p->flags |= PBUF_FLAG_LLBCAST;
157     }
158   }
159 
160   switch (type) {
161 #if LWIP_IPV4 && LWIP_ARP
162     /* IP packet? */
163     case PP_HTONS(ETHTYPE_IP):
164       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
165         goto free_and_return;
166       }
167       /* skip Ethernet header */
168       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
169         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
170           ("ethernet_input: IPv4 packet dropped, too short (%"S16_F"/%"S16_F")\n",
171           p->tot_len, ip_hdr_offset));
172         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
173         goto free_and_return;
174       } else {
175         /* pass to IP layer */
176         ip4_input(p, netif);
177       }
178       break;
179 
180     case PP_HTONS(ETHTYPE_ARP):
181       if (!(netif->flags & NETIF_FLAG_ETHARP)) {
182         goto free_and_return;
183       }
184       /* skip Ethernet header */
185       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
186         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
187           ("ethernet_input: ARP response packet dropped, too short (%"S16_F"/%"S16_F")\n",
188           p->tot_len, ip_hdr_offset));
189         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("Can't move over header in packet"));
190         ETHARP_STATS_INC(etharp.lenerr);
191         ETHARP_STATS_INC(etharp.drop);
192         goto free_and_return;
193       } else {
194         /* pass p to ARP module */
195         etharp_input(p, netif);
196       }
197       break;
198 #endif /* LWIP_IPV4 && LWIP_ARP */
199 #if PPPOE_SUPPORT
200     case PP_HTONS(ETHTYPE_PPPOEDISC): /* PPP Over Ethernet Discovery Stage */
201       pppoe_disc_input(netif, p);
202       break;
203 
204     case PP_HTONS(ETHTYPE_PPPOE): /* PPP Over Ethernet Session Stage */
205       pppoe_data_input(netif, p);
206       break;
207 #endif /* PPPOE_SUPPORT */
208 
209 #if LWIP_IPV6
210     case PP_HTONS(ETHTYPE_IPV6): /* IPv6 */
211       /* skip Ethernet header */
212       if ((p->len < ip_hdr_offset) || pbuf_header(p, (s16_t)-ip_hdr_offset)) {
213         LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
214           ("ethernet_input: IPv6 packet dropped, too short (%"S16_F"/%"S16_F")\n",
215           p->tot_len, ip_hdr_offset));
216         goto free_and_return;
217       } else {
218         /* pass to IPv6 layer */
219         ip6_input(p, netif);
220       }
221       break;
222 #endif /* LWIP_IPV6 */
223 
224     default:
225 #ifdef LWIP_HOOK_UNKNOWN_ETH_PROTOCOL
226       if(LWIP_HOOK_UNKNOWN_ETH_PROTOCOL(p, netif) == ERR_OK) {
227         break;
228       }
229 #endif
230       ETHARP_STATS_INC(etharp.proterr);
231       ETHARP_STATS_INC(etharp.drop);
232       MIB2_STATS_NETIF_INC(netif, ifinunknownprotos);
233       goto free_and_return;
234   }
235 
236   /* This means the pbuf is freed or consumed,
237      so the caller doesn't have to free it again */
238   return ERR_OK;
239 
240 free_and_return:
241   pbuf_free(p);
242   return ERR_OK;
243 }
244 
245 /**
246  * @ingroup ethernet
247  * Send an ethernet packet on the network using netif->linkoutput().
248  * The ethernet header is filled in before sending.
249  *
250  * @see LWIP_HOOK_VLAN_SET
251  *
252  * @param netif the lwIP network interface on which to send the packet
253  * @param p the packet to send. pbuf layer must be @ref PBUF_LINK.
254  * @param src the source MAC address to be copied into the ethernet header
255  * @param dst the destination MAC address to be copied into the ethernet header
256  * @param eth_type ethernet type (@ref eth_type)
257  * @return ERR_OK if the packet was sent, any other err_t on failure
258  */
259 err_t
260 ethernet_output(struct netif* netif, struct pbuf* p,
261                 const struct eth_addr* src, const struct eth_addr* dst,
262                 u16_t eth_type)
263 {
264   struct eth_hdr* ethhdr;
265   u16_t eth_type_be = lwip_htons(eth_type);
266 
267 #if ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET)
268   s32_t vlan_prio_vid = LWIP_HOOK_VLAN_SET(netif, p, src, dst, eth_type);
269   if (vlan_prio_vid >= 0) {
270     struct eth_vlan_hdr* vlanhdr;
271 
272     LWIP_ASSERT("prio_vid must be <= 0xFFFF", vlan_prio_vid <= 0xFFFF);
273 
274     if (pbuf_header(p, SIZEOF_ETH_HDR + SIZEOF_VLAN_HDR) != 0) {
275       goto pbuf_header_failed;
276     }
277     vlanhdr = (struct eth_vlan_hdr*)(((u8_t*)p->payload) + SIZEOF_ETH_HDR);
278     vlanhdr->tpid     = eth_type_be;
279     vlanhdr->prio_vid = lwip_htons((u16_t)vlan_prio_vid);
280 
281     eth_type_be = PP_HTONS(ETHTYPE_VLAN);
282   } else
283 #endif /* ETHARP_SUPPORT_VLAN && defined(LWIP_HOOK_VLAN_SET) */
284   {
285     if (pbuf_header(p, SIZEOF_ETH_HDR) != 0) {
286       goto pbuf_header_failed;
287     }
288   }
289 
290   ethhdr = (struct eth_hdr*)p->payload;
291   ethhdr->type = eth_type_be;
292   ETHADDR32_COPY(&ethhdr->dest, dst);
293   ETHADDR16_COPY(&ethhdr->src,  src);
294 
295   LWIP_ASSERT("netif->hwaddr_len must be 6 for ethernet_output!",
296     (netif->hwaddr_len == ETH_HWADDR_LEN));
297   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,
298     ("ethernet_output: sending packet %p\n", (void *)p));
299 
300   /* send the packet */
301   return netif->linkoutput(netif, p);
302 
303 pbuf_header_failed:
304   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
305     ("ethernet_output: could not allocate room for header.\n"));
306   LINK_STATS_INC(link.lenerr);
307   return ERR_BUF;
308 }
309 
310 #endif /* LWIP_ARP || LWIP_ETHERNET */
311