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      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
     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 *
     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
     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
     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