usr/src/lib/libsocket/inet/link_addr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*
  30  * Function implementations to convert between link layer addresses and
  31  * ascii representations of the form "x:x:x:...:x:x:x" where x is a hex
  32  * number between 0x00 and 0xff; the bytes are always in network order.
  33  */
  34
  35 #include <stdio.h>
  36 #include <ctype.h>
  37 #include <stdlib.h>
  38 #include <sys/types.h>
  39 #include <net/if_dl.h>
  40
  41 /*
  42  * Converts a "size" bytes long mac address to its string representation.
  43  * Currently, the "mactype" is unused, but in the future, the string
  44  * can be modulated by "mactype" (IFT_* value from <net/if_types.h>)
  45  */
  46 /* ARGSUSED */
  47 char *
  48 _link_ntoa(const unsigned char *macaddr, char *str, int size, int mactype)
  49 {
  50         char *buf;
  51         int i, n;
  52
  53         if (((buf = str) == NULL) &&
  54             ((buf = malloc(3 * size)) == NULL))
  55                 return (NULL);
  56         n = sprintf(buf, "%x", *macaddr++);
  57         for (i = 0; i < (size - 1); i++)
  58                 n += sprintf(buf+n, ":%x", *macaddr++);
  59         return (buf);
  60 }
  61
  62 /*
  63  * Converts a string possibly representing a link address into its
  64  * bit format, returning length of the address in bytes.
  65  */
  66 uchar_t *
  67 _link_aton(const char *ascaddr, int *maclen)
  68 {
  69         unsigned char cval, num = 0;
  70         int idx = 0, numcolons = 0, digits = 0;
  71         uchar_t *netaddr;
  72         const char *cptr;
  73         char lastc = ':';
  74
  75         while (isspace(*ascaddr))
  76                 ascaddr++;
  77
  78         /*
  79          * Find how many :'s in the string. Also sanity check
  80          * the string for valid hex chars, absence of white
  81          * spaces, not starting or ending with :, absence of
  82          * consecutive :'s, excessive digits per element
  83          * and non-null string.
  84          */
  85         cptr = ascaddr;
  86         while ((cval = *cptr++) != '\0') {
  87                 if (cval == ':') {
  88                         if (lastc == ':')
  89                                 break;
  90                         numcolons++;
  91                         digits = 0;
  92                 } else if (!isxdigit(cval)) {
  93                         break;
  94                 } else {
  95                         digits++;
  96                 }
  97
  98                 if (digits > 2)
  99                         break;
 100
 101                 lastc = cval;
 102         }
 103         if ((lastc == ':') || (cval != '\0' && !isspace(cval)) ||
 104             (digits > 2)) {
 105                 *maclen = -1;
 106                 return (NULL);
 107         }
 108
 109         if ((netaddr = malloc(numcolons + 1)) == NULL) {
 110                 *maclen = 0;
 111                 return (NULL);
 112         }
 113
 114         for (;;) {
 115                 cval = *ascaddr++;
 116                 if (isdigit(cval)) {
 117                         num = (num << 4) | (cval - '0');
 118                 } else if (isxdigit(cval)) {
 119                         num = (num << 4) |
 120                             (cval - (isupper(cval) ? 'A' : 'a') + 10);
 121                 } else if (cval == ':') {
 122                         netaddr[idx++] = num;
 123                         num = 0;
 124                 } else {
 125                         /*
 126                          * We must have hit a whitespace. Stop
 127                          * parsing now.
 128                          */
 129                         netaddr[idx++] = num;
 130                         break;
 131                 }
 132         }
 133         *maclen = idx;
 134         return (netaddr);
 135 }