1 /*        $NetBSD: dl_print.c,v 1.8 2021/05/27 13:40:38 christos Exp $          */
2 
3 /*-
4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
5  * 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  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 #include <sys/cdefs.h>
29 #include <sys/types.h>
30 
31 #ifdef _KERNEL
32 __KERNEL_RCSID(0, "$NetBSD: dl_print.c,v 1.8 2021/05/27 13:40:38 christos Exp $");
33 #include <sys/systm.h>
34 #else
35 __RCSID("$NetBSD: dl_print.c,v 1.8 2021/05/27 13:40:38 christos Exp $");
36 #include <stdio.h>
37 static const char hexdigits[] = "0123456789abcdef";
38 #endif
39 #include <net/if_dl.h>
40 
41 static int
lla_snprintf1(char * dst,size_t dst_len,const void * src,size_t src_len)42 lla_snprintf1(char *dst, size_t dst_len, const void *src, size_t src_len)
43 {
44           char *dp;
45           const uint8_t *sp, *ep;
46 
47           dp = dst;
48           sp = (const uint8_t *)src;
49           ep = sp + src_len;
50           while (sp < ep) {
51                     if (dst_len-- == 0)
52                               break;
53                     *dp++ = hexdigits[(*sp) >> 4];
54                     if (dst_len-- == 0)
55                               break;
56                     *dp++ = hexdigits[(*sp++) & 0xf];
57                     if (dst_len-- == 0)
58                               break;
59                     *dp++ = ':';
60           }
61           if (dp != dst)
62                     *--dp = '\0';
63 
64           return src_len ? (int)(src_len * 3) - 1 : 0;
65 }
66 
67 char *
lla_snprintf(char * dst,size_t dst_len,const void * src,size_t src_len)68 lla_snprintf(char *dst, size_t dst_len, const void *src, size_t src_len)
69 {
70           (void)lla_snprintf1(dst, dst_len, src, src_len);
71           return dst;
72 }
73 
74 #define clip(a, b) ((a) > (size_t)(b) ? (a) - (size_t)(b) : 0)
75 
76 int
dl_print(char * buf,size_t len,const struct dl_addr * dl)77 dl_print(char *buf, size_t len, const struct dl_addr *dl)
78 {
79           int l = snprintf(buf, len, "%.*s/%hhu#",
80               (int)dl->dl_nlen, dl->dl_data, dl->dl_type);
81           if (l == -1)
82                     return l;
83           int ll = lla_snprintf1(buf + l, clip(len, l),
84               dl->dl_data + dl->dl_nlen, dl->dl_alen);
85           if (ll == -1)
86                     return ll;
87 
88           return ll + l;
89 }
90 
91 int
sdl_print(char * buf,size_t len,const void * v)92 sdl_print(char *buf, size_t len, const void *v)
93 {
94           const struct sockaddr_dl *sdl = v;
95 
96           if (sdl->sdl_slen == 0 && sdl->sdl_nlen == 0 && sdl->sdl_alen == 0)
97                     return snprintf(buf, len, "link#%hu", sdl->sdl_index);
98 
99           if (len > 0) {
100                     buf[0] = '[';
101                     len--;
102           }
103           int l = dl_print(buf + 1, len, &sdl->sdl_addr);
104           if (l == -1)
105                     return l;
106           l++;
107           len++;
108           int ll = snprintf(buf + l, clip(len, l), "]:%hu", sdl->sdl_index);
109           if (ll == -1)
110                     return ll;
111           return ll + l;
112 }
113