xref: /freebsd-13-stable/sys/mips/atheros/ar71xx_macaddr.c (revision 3bc80996974a61a4223eae4c1ccd47b6ee32a48a)
1 /*-
2  * Copyright (c) 2015, Adrian Chadd <adrian@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/types.h>
32 #include <sys/libkern.h>
33 
34 #include <net/ethernet.h>
35 
36 #include <mips/atheros/ar71xx_macaddr.h>
37 
38 /*
39  * Some boards don't have a separate MAC address for each individual
40  * device on-board, but instead need to derive them from a single MAC
41  * address stored somewhere.
42  */
43 uint8_t ar71xx_board_mac_addr[ETHER_ADDR_LEN];
44 
45 /*
46  * Initialise a MAC address 'dst' from a MAC address 'src'.
47  *
48  * 'offset' is added to the low three bytes to allow for sequential
49  * MAC addresses to be derived from a single one.
50  *
51  * 'is_local' is whether this 'dst' should be made a local MAC address.
52  *
53  * Returns 0 if it was successfully initialised, -1 on error.
54  */
55 int
ar71xx_mac_addr_init(unsigned char * dst,const unsigned char * src,int offset,int is_local)56 ar71xx_mac_addr_init(unsigned char *dst, const unsigned char *src,
57     int offset, int is_local)
58 {
59 	int t;
60 
61 	if (dst == NULL || src == NULL)
62 		return (-1);
63 
64 	/* XXX TODO: validate 'src' is a valid MAC address */
65 
66 	t = (((uint32_t) src[3]) << 16)
67 	    + (((uint32_t) src[4]) << 8)
68 	    + ((uint32_t) src[5]);
69 
70 	/* Note: this is handles both positive and negative offsets */
71 	t += offset;
72 
73 	dst[0] = src[0];
74 	dst[1] = src[1];
75 	dst[2] = src[2];
76 	dst[3] = (t >> 16) & 0xff;
77 	dst[4] = (t >> 8) & 0xff;
78 	dst[5] = t & 0xff;
79 
80 	if (is_local)
81 		dst[0] |= 0x02;
82 
83 	/* Everything's okay */
84 	return (0);
85 }
86 
87 /*
88  * Initialise a random MAC address for use by if_arge.c and whatever
89  * else requires it.
90  *
91  * Returns 0 on success, -1 on error.
92  */
93 int
ar71xx_mac_addr_random_init(struct ifnet * ifp,struct ether_addr * dst)94 ar71xx_mac_addr_random_init(struct ifnet *ifp, struct ether_addr *dst)
95 {
96 
97 	ether_gen_addr(ifp, dst);
98 	return (0);
99 }
100