net/FreeBSD/linkaddr.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)linkaddr.c  8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/net/linkaddr.c,v 1.4 2007/01/09 00:28:02 imp Exp $");
  35
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <net/if_dl.h>
  39 #include <string.h>
  40
  41 /* States*/
  42 #define NAMING  0
  43 #define GOTONE  1
  44 #define GOTTWO  2
  45 #define RESET   3
  46 /* Inputs */
  47 #define DIGIT   (4*0)
  48 #define END     (4*1)
  49 #define DELIM   (4*2)
  50 #define LETTER  (4*3)
  51
  52 void
  53 link_addr(const char *addr, struct sockaddr_dl *sdl)
  54 {
  55         char *cp = sdl->sdl_data;
  56         char *cplim = sdl->sdl_len + (char *)sdl;
  57         int byte = 0, state = NAMING, new;
  58
  59         bzero((char *)&sdl->sdl_family, sdl->sdl_len - 1);
  60         sdl->sdl_family = AF_LINK;
  61         do {
  62                 state &= ~LETTER;
  63                 if ((*addr >= '0') && (*addr <= '9')) {
  64                         new = *addr - '0';
  65                 } else if ((*addr >= 'a') && (*addr <= 'f')) {
  66                         new = *addr - 'a' + 10;
  67                 } else if ((*addr >= 'A') && (*addr <= 'F')) {
  68                         new = *addr - 'A' + 10;
  69                 } else if (*addr == 0) {
  70                         state |= END;
  71                 } else if (state == NAMING &&
  72                            (((*addr >= 'A') && (*addr <= 'Z')) ||
  73                            ((*addr >= 'a') && (*addr <= 'z'))))
  74                         state |= LETTER;
  75                 else
  76                         state |= DELIM;
  77                 addr++;
  78                 switch (state /* | INPUT */) {
  79                 case NAMING | DIGIT:
  80                 case NAMING | LETTER:
  81                         *cp++ = addr[-1];
  82                         continue;
  83                 case NAMING | DELIM:
  84                         state = RESET;
  85                         sdl->sdl_nlen = cp - sdl->sdl_data;
  86                         continue;
  87                 case GOTTWO | DIGIT:
  88                         *cp++ = byte;
  89                         /* FALLTHROUGH */
  90                 case RESET | DIGIT:
  91                         state = GOTONE;
  92                         byte = new;
  93                         continue;
  94                 case GOTONE | DIGIT:
  95                         state = GOTTWO;
  96                         byte = new + (byte << 4);
  97                         continue;
  98                 default: /* | DELIM */
  99                         state = RESET;
 100                         *cp++ = byte;
 101                         byte = 0;
 102                         continue;
 103                 case GOTONE | END:
 104                 case GOTTWO | END:
 105                         *cp++ = byte;
 106                         /* FALLTHROUGH */
 107                 case RESET | END:
 108                         break;
 109                 }
 110                 break;
 111         } while (cp < cplim);
 112         sdl->sdl_alen = cp - LLADDR(sdl);
 113         new = cp - (char *)sdl;
 114         if (new > sizeof(*sdl))
 115                 sdl->sdl_len = new;
 116         return;
 117 }
 118
 119 static const char hexlist[] = "0123456789abcdef";
 120
 121 char *
 122 link_ntoa(const struct sockaddr_dl *sdl)
 123 {
 124         static char obuf[64];
 125         char *out = obuf;
 126         int i;
 127         u_char *in = (u_char *)LLADDR(sdl);
 128         u_char *inlim = in + sdl->sdl_alen;
 129         int firsttime = 1;
 130
 131         /*
 132          * the length of the output string is length of network name (eg "le0")
 133          * plus 3 * each byte (eg. "XX.") assuming the print representation is
 134          * two bytes plus the period
 135          *
 136          * The ":" is accounted for as the last byte doesn't have a "." at the
 137          * end
 138          */
 139         if (sdl->sdl_nlen + 3*sdl->sdl_alen >= sizeof(obuf)) {
 140                 goto exit;
 141         }
 142
 143         if (sdl->sdl_nlen) {
 144                 bcopy(sdl->sdl_data, obuf, sdl->sdl_nlen);
 145                 out += sdl->sdl_nlen;
 146                 if (sdl->sdl_alen)
 147                         *out++ = ':';
 148         }
 149         while (in < inlim) {
 150                 if (firsttime)
 151                         firsttime = 0;
 152                 else
 153                         *out++ = '.';
 154                 i = *in++;
 155                 if (i > 0xf) {
 156                         out[1] = hexlist[i & 0xf];
 157                         i >>= 4;
 158                         out[0] = hexlist[i];
 159                         out += 2;
 160                 } else {
 161                         *out++ = hexlist[i];
 162                 }
 163         }
 164
 165 exit:
 166         *out = 0;
 167         return (obuf);
 168 }