1 /* $NetBSD: linkaddr.c,v 1.23 2022/04/19 20:32:15 rillig 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 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)linkaddr.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: linkaddr.c,v 1.23 2022/04/19 20:32:15 rillig Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 #include <sys/socket.h> 43 #include <net/if_dl.h> 44 45 #include <assert.h> 46 #include <string.h> 47 48 /* States*/ 49 #define NAMING 0 50 #define GOTONE 1 51 #define GOTTWO 2 52 #define RESET 3 53 /* Inputs */ 54 #define DIGIT (4*0) 55 #define END (4*1) 56 #define DELIM (4*2) 57 #define LETTER (4*3) 58 59 void 60 link_addr(const char *addr, struct sockaddr_dl *sdl) 61 { 62 char *cp = sdl->sdl_data; 63 char *cplim = sdl->sdl_len + (char *)(void *)sdl; 64 int byte = 0, state = NAMING; 65 size_t newaddr = 0; /* pacify gcc */ 66 67 _DIAGASSERT(addr != NULL); 68 _DIAGASSERT(sdl != NULL); 69 70 (void)memset(&sdl->sdl_family, 0, (size_t)sdl->sdl_len - 1); 71 sdl->sdl_family = AF_LINK; 72 do { 73 state &= ~LETTER; 74 if ((*addr >= '0') && (*addr <= '9')) { 75 newaddr = *addr - '0'; 76 } else if ((*addr >= 'a') && (*addr <= 'f')) { 77 newaddr = *addr - 'a' + 10; 78 } else if ((*addr >= 'A') && (*addr <= 'F')) { 79 newaddr = *addr - 'A' + 10; 80 } else if (*addr == 0) { 81 state |= END; 82 } else if (state == NAMING && 83 (((*addr >= 'A') && (*addr <= 'Z')) || 84 ((*addr >= 'a') && (*addr <= 'z')))) 85 state |= LETTER; 86 else 87 state |= DELIM; 88 addr++; 89 switch (state /* | INPUT */) { 90 case NAMING | DIGIT: 91 case NAMING | LETTER: 92 *cp++ = addr[-1]; 93 continue; 94 case NAMING | DELIM: 95 state = RESET; 96 _DIAGASSERT(__type_fit(uint8_t, cp - sdl->sdl_data)); 97 sdl->sdl_nlen = (uint8_t)(cp - sdl->sdl_data); 98 continue; 99 case GOTTWO | DIGIT: 100 *cp++ = byte; 101 /* FALLTHROUGH */ 102 case RESET | DIGIT: 103 state = GOTONE; 104 byte = (int)newaddr; 105 continue; 106 case GOTONE | DIGIT: 107 state = GOTTWO; 108 byte = (int)newaddr + (byte << 4); 109 continue; 110 default: /* | DELIM */ 111 state = RESET; 112 *cp++ = byte; 113 byte = 0; 114 continue; 115 case GOTONE | END: 116 case GOTTWO | END: 117 *cp++ = byte; 118 /* FALLTHROUGH */ 119 case RESET | END: 120 break; 121 } 122 break; 123 } while (cp < cplim); 124 125 _DIAGASSERT(__type_fit(uint8_t, cp - LLADDR(sdl))); 126 sdl->sdl_alen = (uint8_t)(cp - LLADDR(sdl)); 127 newaddr = cp - (char *)(void *)sdl; 128 if (newaddr > sizeof(*sdl)) { 129 _DIAGASSERT(__type_fit(uint8_t, newaddr)); 130 sdl->sdl_len = (uint8_t)newaddr; 131 } 132 return; 133 } 134 135 static const char hexlist[16] = "0123456789abcdef"; 136 137 char * 138 link_ntoa(const struct sockaddr_dl *sdl) 139 { 140 static char obuf[64]; 141 char *out = obuf; 142 size_t i; 143 const u_char *in = (const u_char *)CLLADDR(sdl); 144 const u_char *inlim = in + sdl->sdl_alen; 145 int firsttime = 1; 146 147 _DIAGASSERT(sdl != NULL); 148 149 #define ADDC(ch) \ 150 do { \ 151 if (out >= obuf + sizeof(obuf) - 1) \ 152 return obuf; \ 153 *out++ = (ch); \ 154 } while (0) 155 156 /* 157 * This is not needed on the first call, as the static 158 * obuf wil be fully init'd to 0 by default. But after 159 * obuf has been returned to userspace the first time, 160 * anything may have been written to it, so, let's be safe. 161 * 162 * (An alternative method would be to make ADDC() more 163 * complex: 164 * if (out < obuf + sizeof(obuf) - ((ch) != '\0')) 165 * *out++ = (ch); 166 * so it never returns, and the final ADDC(0) always works 167 * but that evaluates 'ch' twice, and is slower, so ...) 168 */ 169 obuf[sizeof(obuf) - 1] = '\0'; 170 171 if (sdl->sdl_nlen) { 172 if (sdl->sdl_nlen >= sizeof(obuf)) 173 i = sizeof(obuf) - 1; 174 else 175 i = sdl->sdl_nlen; 176 (void)memcpy(obuf, sdl->sdl_data, i); 177 out += i; 178 if (sdl->sdl_alen) 179 ADDC(':'); 180 } 181 while (in < inlim) { 182 if (firsttime) 183 firsttime = 0; 184 else 185 ADDC('.'); 186 i = *in++; 187 if (i > 0xf) { 188 size_t j = i & 0xf; 189 i >>= 4; 190 ADDC(hexlist[i]); 191 ADDC(hexlist[j]); 192 } else 193 ADDC(hexlist[i]); 194 } 195 ADDC('\0'); 196 return obuf; 197 } 198
Indexes created Mon Sep 22 21:09:42 GMT 2025