contrib/tcpdump/strtoaddr.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1996,1999 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include <config.h>
  20 #endif
  21
  22 #include "netdissect-stdinc.h"
  23 #include <stddef.h>
  24 #include <string.h>
  25
  26 #include "netdissect-ctype.h"
  27
  28 #include "strtoaddr.h"
  29
  30 #ifndef NS_INADDRSZ
  31 #define NS_INADDRSZ     4       /* IPv4 T_A */
  32 #endif
  33
  34 #ifndef NS_IN6ADDRSZ
  35 #define NS_IN6ADDRSZ    16      /* IPv6 T_AAAA */
  36 #endif
  37
  38 #ifndef NS_INT16SZ
  39 #define NS_INT16SZ      2       /* #/bytes of data in a uint16_t */
  40 #endif
  41
  42 /*%
  43  * WARNING: Don't even consider trying to compile this on a system where
  44  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  45  */
  46
  47 /* int
  48  * strtoaddr(src, dst)
  49  *      convert presentation level IPv4 address to network order binary form.
  50  * return:
  51  *      1 if `src' is a valid input, else 0.
  52  * notice:
  53  *      does not touch `dst' unless it's returning 1.
  54  * author:
  55  *      Paul Vixie, 1996.
  56  */
  57 int
  58 strtoaddr(const char *src, void *dst)
  59 {
  60         uint32_t val;
  61         u_int digit;
  62         ptrdiff_t n;
  63         unsigned char c;
  64         u_int parts[4];
  65         u_int *pp = parts;
  66
  67         c = *src;
  68         for (;;) {
  69                 /*
  70                  * Collect number up to ``.''.
  71                  * Values are specified as for C:
  72                  * 0x=hex, 0=octal, isdigit=decimal.
  73                  */
  74                 if (!ND_ASCII_ISDIGIT(c))
  75                         return (0);
  76                 val = 0;
  77                 if (c == '0') {
  78                         c = *++src;
  79                         if (c == 'x' || c == 'X')
  80                                 return (0);
  81                         else if (ND_ASCII_ISDIGIT(c) && c != '9')
  82                                 return (0);
  83                 }
  84                 for (;;) {
  85                         if (ND_ASCII_ISDIGIT(c)) {
  86                                 digit = c - '0';
  87                                 val = (val * 10) + digit;
  88                                 c = *++src;
  89                         } else
  90                                 break;
  91                 }
  92                 if (c == '.') {
  93                         /*
  94                          * Internet format:
  95                          *      a.b.c.d
  96                          *      a.b.c   (with c treated as 16 bits)
  97                          *      a.b     (with b treated as 24 bits)
  98                          *      a       (with a treated as 32 bits)
  99                          */
 100                         if (pp >= parts + 3)
 101                                 return (0);
 102                         *pp++ = val;
 103                         c = *++src;
 104                 } else
 105                         break;
 106         }
 107         /*
 108          * Check for trailing characters.
 109          */
 110         if (c != '\0' && c != ' ' && c != '\t')
 111                 return (0);
 112         /*
 113          * Find the number of parts specified.
 114          * It must be 4; we only support dotted quads, we don't
 115          * support shorthand.
 116          */
 117         n = pp - parts + 1;
 118         if (n != 4)
 119                 return (0);
 120         /*
 121          * parts[0-2] were set to the first 3 parts of the address;
 122          * val was set to the 4th part.
 123          *
 124          * Check if any part is bigger than 255.
 125          */
 126         if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
 127                 return (0);
 128         /*
 129          * Add the other three parts to val.
 130          */
 131         val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 132         if (dst) {
 133                 val = htonl(val);
 134                 memcpy(dst, &val, NS_INADDRSZ);
 135         }
 136         return (1);
 137 }
 138
 139 /* int
 140  * strtoaddr6(src, dst)
 141  *      convert presentation level IPv6 address to network order binary form.
 142  * return:
 143  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 144  * notice:
 145  *      (1) does not touch `dst' unless it's returning 1.
 146  *      (2) :: in a full address is silently ignored.
 147  * credit:
 148  *      inspired by Mark Andrews.
 149  * author:
 150  *      Paul Vixie, 1996.
 151  */
 152 int
 153 strtoaddr6(const char *src, void *dst)
 154 {
 155         static const char xdigits_l[] = "0123456789abcdef",
 156                           xdigits_u[] = "0123456789ABCDEF";
 157         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 158         const char *xdigits, *curtok;
 159         int ch, seen_xdigits;
 160         u_int val;
 161
 162         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 163         endp = tp + NS_IN6ADDRSZ;
 164         colonp = NULL;
 165         /* Leading :: requires some special handling. */
 166         if (*src == ':')
 167                 if (*++src != ':')
 168                         return (0);
 169         curtok = src;
 170         seen_xdigits = 0;
 171         val = 0;
 172         while ((ch = *src++) != '\0') {
 173                 const char *pch;
 174
 175                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 176                         pch = strchr((xdigits = xdigits_u), ch);
 177                 if (pch != NULL) {
 178                         val <<= 4;
 179                         val |= (int)(pch - xdigits);
 180                         if (++seen_xdigits > 4)
 181                                 return (0);
 182                         continue;
 183                 }
 184                 if (ch == ':') {
 185                         curtok = src;
 186                         if (!seen_xdigits) {
 187                                 if (colonp)
 188                                         return (0);
 189                                 colonp = tp;
 190                                 continue;
 191                         } else if (*src == '\0')
 192                                 return (0);
 193                         if (tp + NS_INT16SZ > endp)
 194                                 return (0);
 195                         *tp++ = (u_char) (val >> 8) & 0xff;
 196                         *tp++ = (u_char) val & 0xff;
 197                         seen_xdigits = 0;
 198                         val = 0;
 199                         continue;
 200                 }
 201                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 202                     strtoaddr(curtok, tp) > 0) {
 203                         tp += NS_INADDRSZ;
 204                         seen_xdigits = 0;
 205                         break;  /*%< '\\0' was seen by strtoaddr(). */
 206                 }
 207                 return (0);
 208         }
 209         if (seen_xdigits) {
 210                 if (tp + NS_INT16SZ > endp)
 211                         return (0);
 212                 *tp++ = (u_char) (val >> 8) & 0xff;
 213                 *tp++ = (u_char) val & 0xff;
 214         }
 215         if (colonp != NULL) {
 216                 /*
 217                  * Since some memmove()'s erroneously fail to handle
 218                  * overlapping regions, we'll do the shift by hand.
 219                  */
 220                 const ptrdiff_t n = tp - colonp;
 221                 int i;
 222
 223                 if (tp == endp)
 224                         return (0);
 225                 for (i = 1; i <= n; i++) {
 226                         endp[- i] = colonp[n - i];
 227                         colonp[n - i] = 0;
 228                 }
 229                 tp = endp;
 230         }
 231         if (tp != endp)
 232                 return (0);
 233         memcpy(dst, tmp, NS_IN6ADDRSZ);
 234         return (1);
 235 }