[zbin] Fix check for existence of most recent output byte
[ipxe.git] / src / net / ethernet.c
1 /*
2 * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 */
19
20 FILE_LICENCE ( GPL2_OR_LATER );
21
22 #include <stdint.h>
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include <byteswap.h>
27 #include <errno.h>
28 #include <assert.h>
29 #include <ipxe/if_arp.h>
30 #include <ipxe/if_ether.h>
31 #include <ipxe/in.h>
32 #include <ipxe/netdevice.h>
33 #include <ipxe/iobuf.h>
34 #include <ipxe/ethernet.h>
35
36 /** @file
37 *
38 * Ethernet protocol
39 *
40 */
41
42 /** Ethernet broadcast MAC address */
43 uint8_t eth_broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
44
45 /**
46 * Add Ethernet link-layer header
47 *
48 * @v netdev Network device
49 * @v iobuf I/O buffer
50 * @v ll_dest Link-layer destination address
51 * @v ll_source Source link-layer address
52 * @v net_proto Network-layer protocol, in network-byte order
53 * @ret rc Return status code
54 */
55 int eth_push ( struct net_device *netdev __unused, struct io_buffer *iobuf,
56 const void *ll_dest, const void *ll_source,
57 uint16_t net_proto ) {
58 struct ethhdr *ethhdr = iob_push ( iobuf, sizeof ( *ethhdr ) );
59
60 /* Build Ethernet header */
61 memcpy ( ethhdr->h_dest, ll_dest, ETH_ALEN );
62 memcpy ( ethhdr->h_source, ll_source, ETH_ALEN );
63 ethhdr->h_protocol = net_proto;
64
65 return 0;
66 }
67
68 /**
69 * Remove Ethernet link-layer header
70 *
71 * @v netdev Network device
72 * @v iobuf I/O buffer
73 * @ret ll_dest Link-layer destination address
74 * @ret ll_source Source link-layer address
75 * @ret net_proto Network-layer protocol, in network-byte order
76 * @ret flags Packet flags
77 * @ret rc Return status code
78 */
79 int eth_pull ( struct net_device *netdev __unused, struct io_buffer *iobuf,
80 const void **ll_dest, const void **ll_source,
81 uint16_t *net_proto, unsigned int *flags ) {
82 struct ethhdr *ethhdr = iobuf->data;
83
84 /* Sanity check */
85 if ( iob_len ( iobuf ) < sizeof ( *ethhdr ) ) {
86 DBG ( "Ethernet packet too short (%zd bytes)\n",
87 iob_len ( iobuf ) );
88 return -EINVAL;
89 }
90
91 /* Strip off Ethernet header */
92 iob_pull ( iobuf, sizeof ( *ethhdr ) );
93
94 /* Fill in required fields */
95 *ll_dest = ethhdr->h_dest;
96 *ll_source = ethhdr->h_source;
97 *net_proto = ethhdr->h_protocol;
98 *flags = ( ( is_multicast_ether_addr ( ethhdr->h_dest ) ?
99 LL_MULTICAST : 0 ) |
100 ( is_broadcast_ether_addr ( ethhdr->h_dest ) ?
101 LL_BROADCAST : 0 ) );
102
103 return 0;
104 }
105
106 /**
107 * Initialise Ethernet address
108 *
109 * @v hw_addr Hardware address
110 * @v ll_addr Link-layer address
111 */
112 void eth_init_addr ( const void *hw_addr, void *ll_addr ) {
113 memcpy ( ll_addr, hw_addr, ETH_ALEN );
114 }
115
116 /**
117 * Generate random Ethernet address
118 *
119 * @v hw_addr Generated hardware address
120 */
121 void eth_random_addr ( void *hw_addr ) {
122 uint8_t *addr = hw_addr;
123 unsigned int i;
124
125 for ( i = 0 ; i < ETH_ALEN ; i++ )
126 addr[i] = random();
127 addr[0] &= ~0x01; /* Clear multicast bit */
128 addr[0] |= 0x02; /* Set locally-assigned bit */
129 }
130
131 /**
132 * Transcribe Ethernet address
133 *
134 * @v ll_addr Link-layer address
135 * @ret string Link-layer address in human-readable format
136 */
137 const char * eth_ntoa ( const void *ll_addr ) {
138 static char buf[18]; /* "00:00:00:00:00:00" */
139 const uint8_t *eth_addr = ll_addr;
140
141 sprintf ( buf, "%02x:%02x:%02x:%02x:%02x:%02x",
142 eth_addr[0], eth_addr[1], eth_addr[2],
143 eth_addr[3], eth_addr[4], eth_addr[5] );
144 return buf;
145 }
146
147 /**
148 * Hash multicast address
149 *
150 * @v af Address family
151 * @v net_addr Network-layer address
152 * @v ll_addr Link-layer address to fill in
153 * @ret rc Return status code
154 */
155 int eth_mc_hash ( unsigned int af, const void *net_addr, void *ll_addr ) {
156 const uint8_t *net_addr_bytes = net_addr;
157 uint8_t *ll_addr_bytes = ll_addr;
158
159 switch ( af ) {
160 case AF_INET:
161 ll_addr_bytes[0] = 0x01;
162 ll_addr_bytes[1] = 0x00;
163 ll_addr_bytes[2] = 0x5e;
164 ll_addr_bytes[3] = net_addr_bytes[1] & 0x7f;
165 ll_addr_bytes[4] = net_addr_bytes[2];
166 ll_addr_bytes[5] = net_addr_bytes[3];
167 return 0;
168 case AF_INET6:
169 ll_addr_bytes[0] = 0x33;
170 ll_addr_bytes[1] = 0x33;
171 memcpy ( &ll_addr_bytes[2], &net_addr_bytes[12], 4 );
172 return 0;
173 default:
174 return -ENOTSUP;
175 }
176 }
177
178 /**
179 * Generate Ethernet-compatible compressed link-layer address
180 *
181 * @v ll_addr Link-layer address
182 * @v eth_addr Ethernet-compatible address to fill in
183 */
184 int eth_eth_addr ( const void *ll_addr, void *eth_addr ) {
185 memcpy ( eth_addr, ll_addr, ETH_ALEN );
186 return 0;
187 }
188
189 /**
190 * Generate EUI-64 address
191 *
192 * @v ll_addr Link-layer address
193 * @v eui64 EUI-64 address to fill in
194 * @ret rc Return status code
195 */
196 int eth_eui64 ( const void *ll_addr, void *eui64 ) {
197
198 memcpy ( ( eui64 + 0 ), ( ll_addr + 0 ), 3 );
199 memcpy ( ( eui64 + 5 ), ( ll_addr + 3 ), 3 );
200 *( ( uint16_t * ) ( eui64 + 3 ) ) = htons ( 0xfffe );
201 return 0;
202 }
203
204 /** Ethernet protocol */
205 struct ll_protocol ethernet_protocol __ll_protocol = {
206 .name = "Ethernet",
207 .ll_proto = htons ( ARPHRD_ETHER ),
208 .hw_addr_len = ETH_ALEN,
209 .ll_addr_len = ETH_ALEN,
210 .ll_header_len = ETH_HLEN,
211 .push = eth_push,
212 .pull = eth_pull,
213 .init_addr = eth_init_addr,
214 .ntoa = eth_ntoa,
215 .mc_hash = eth_mc_hash,
216 .eth_addr = eth_eth_addr,
217 .eui64 = eth_eui64,
218 };
219
220 /**
221 * Allocate Ethernet device
222 *
223 * @v priv_size Size of driver private data
224 * @ret netdev Network device, or NULL
225 */
226 struct net_device * alloc_etherdev ( size_t priv_size ) {
227 struct net_device *netdev;
228
229 netdev = alloc_netdev ( priv_size );
230 if ( netdev ) {
231 netdev->ll_protocol = &ethernet_protocol;
232 netdev->ll_broadcast = eth_broadcast;
233 netdev->max_pkt_len = ETH_FRAME_LEN;
234 }
235 return netdev;
236 }
237
238 /* Drag in Ethernet slow protocols */
239 REQUIRE_OBJECT ( eth_slow );