1 /*        $NetBSD: if_dl.h,v 1.31 2022/11/07 08:32:35 msaitoh Exp $   */
2 
3 /*
4  * Copyright (c) 1990, 1993
5  *        The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *        @(#)if_dl.h         8.1 (Berkeley) 6/10/93
32  */
33 
34 /*
35  * A Link-Level Sockaddr may specify the interface in one of two
36  * ways: either by means of a system-provided index number (computed
37  * anew and possibly differently on every reboot), or by a human-readable
38  * string such as "il0" (for managerial convenience).
39  *
40  * Census taking actions, such as something akin to SIOCGCONF would return
41  * both the index and the human name.
42  *
43  * High volume transactions (such as giving a link-level ``from'' address
44  * in a recvfrom or recvmsg call) may be likely only to provide the indexed
45  * form, (which requires fewer copy operations and less space).
46  *
47  * The form and interpretation  of the link-level address is purely a matter
48  * of convention between the device driver and its consumers; however, it is
49  * expected that all drivers for an interface of a given if_type will agree.
50  */
51 
52 #ifndef _NET_IF_DL_H_
53 #define _NET_IF_DL_H_
54 
55 #include <sys/ansi.h>
56 
57 #ifndef sa_family_t
58 typedef __sa_family_t         sa_family_t;
59 #define sa_family_t __sa_family_t
60 #endif
61 #ifndef socklen_t
62 typedef __socklen_t   socklen_t;
63 #define socklen_t     __socklen_t
64 #endif
65 
66 struct dl_addr {
67           uint8_t       dl_type;        /* interface type */
68           uint8_t       dl_nlen;        /* interface name length, no trailing 0 reqd. */
69           uint8_t       dl_alen;        /* link level address length */
70           uint8_t       dl_slen;        /* link layer selector length */
71           char          dl_data[24]; /*
72                                           * minimum work area, can be larger; contains
73                                           * both if name and ll address; big enough for
74                                           * IFNAMSIZ plus 8byte ll addr.
75                                           */
76 };
77 
78 /*
79  * Structure of a Link-Level sockaddr:
80  */
81 struct sockaddr_dl {
82           uint8_t       sdl_len;        /* Total length of sockaddr */
83           sa_family_t sdl_family;       /* AF_LINK */
84           uint16_t    sdl_index;        /* if != 0, system given index for interface */
85           struct dl_addr sdl_addr;
86 #define sdl_type    sdl_addr.dl_type
87 #define sdl_nlen    sdl_addr.dl_nlen
88 #define sdl_alen    sdl_addr.dl_alen
89 #define sdl_slen    sdl_addr.dl_slen
90 #define sdl_data    sdl_addr.dl_data
91 };
92 
93 #define   satosdl(__sa)       ((struct sockaddr_dl *)(__sa))
94 #define   satocsdl(__sa)      ((const struct sockaddr_dl *)(__sa))
95 
96 /* We do arithmetic directly with these, so keep them char instead of void */
97 #define LLADDR(s) ((char *)((s)->sdl_data + (s)->sdl_nlen))
98 #define CLLADDR(s) ((const char *)((s)->sdl_data + (s)->sdl_nlen))
99 
100 #ifdef _KERNEL
101 uint8_t sockaddr_dl_measure(uint8_t, uint8_t);
102 struct sockaddr *sockaddr_dl_alloc(uint16_t, uint8_t,
103     const void *, uint8_t, const void *, uint8_t, int);
104 struct sockaddr_dl *sockaddr_dl_init(struct sockaddr_dl *, socklen_t, uint16_t,
105     uint8_t, const void *, uint8_t, const void *, uint8_t);
106 struct sockaddr_dl *sockaddr_dl_setaddr(struct sockaddr_dl *, socklen_t,
107     const void *, uint8_t);
108 #else
109 
110 #include <sys/cdefs.h>
111 
112 __BEGIN_DECLS
113 void      link_addr(const char *, struct sockaddr_dl *);
114 char      *link_ntoa(const struct sockaddr_dl *);
115 __END_DECLS
116 
117 #endif /* !_KERNEL */
118 
119 #if defined(_KERNEL) || defined(_TEST)
120 // 255 xx: + 255 'a' + / + # + 3 digits + NUL
121 #define LINK_ADDRSTRLEN       ((255 * 4) + 5)
122 #define LLA_ADDRSTRLEN        (16 * 3)
123 
124 char      *lla_snprintf(char *, size_t, const void *, size_t);
125 int       dl_print(char *, size_t, const struct dl_addr *);
126 #define DL_PRINT(b, a) (dl_print((b), sizeof(b), (a)), (b))
127 int       sdl_print(char *, size_t, const void *);
128 #endif
129 
130 #endif /* !_NET_IF_DL_H_ */
131