1 /* $OpenBSD: linkaddr.c,v 1.7 2016/12/06 22:32:58 millert Exp $ */ 2 /*- 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following 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 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 #include <sys/socket.h> 33 #include <net/if.h> 34 #include <net/if_dl.h> 35 #include <string.h> 36 37 static const char hexlist[] = "0123456789abcdef"; 38 39 char * 40 link_ntoa(const struct sockaddr_dl *sdl) 41 { 42 static char obuf[64]; 43 char *out; 44 const char *in, *inlim; 45 int namelen, i, rem; 46 47 namelen = (sdl->sdl_nlen <= IFNAMSIZ) ? sdl->sdl_nlen : IFNAMSIZ; 48 49 out = obuf; 50 rem = sizeof(obuf); 51 if (namelen > 0) { 52 memcpy(out, sdl->sdl_data, namelen); 53 out += namelen; 54 rem -= namelen; 55 if (sdl->sdl_alen > 0) { 56 *out++ = ':'; 57 rem--; 58 } 59 } 60 61 in = (const char *)sdl->sdl_data + sdl->sdl_nlen; 62 inlim = in + sdl->sdl_alen; 63 64 while (in < inlim && rem > 1) { 65 if (in != (const char *)sdl->sdl_data + sdl->sdl_nlen) { 66 *out++ = '.'; 67 rem--; 68 } 69 i = *in++; 70 if (i > 0xf) { 71 if (rem < 3) 72 break; 73 *out++ = hexlist[i & 0xf]; 74 i >>= 4; 75 *out++ = hexlist[i]; 76 rem -= 2; 77 } else { 78 if (rem < 2) 79 break; 80 *out++ = hexlist[i]; 81 rem++; 82 } 83 } 84 *out = 0; 85 return (obuf); 86 } 87