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 "strtoaddr.h"
  27
  28 #ifndef NS_INADDRSZ
  29 #define NS_INADDRSZ     4       /* IPv4 T_A */
  30 #endif
  31
  32 #ifndef NS_IN6ADDRSZ
  33 #define NS_IN6ADDRSZ    16      /* IPv6 T_AAAA */
  34 #endif
  35
  36 #ifndef NS_INT16SZ
  37 #define NS_INT16SZ      2       /* #/bytes of data in a uint16_t */
  38 #endif
  39
  40 /*%
  41  * WARNING: Don't even consider trying to compile this on a system where
  42  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
  43  */
  44
  45 #ifndef NS_IN6ADDRSZ
  46 #define NS_IN6ADDRSZ   16   /* IPv6 T_AAAA */
  47 #endif
  48
  49 /* int
  50  * strtoaddr(src, dst)
  51  *      convert presentation level IPv4 address to network order binary form.
  52  * return:
  53  *      1 if `src' is a valid input, else 0.
  54  * notice:
  55  *      does not touch `dst' unless it's returning 1.
  56  * author:
  57  *      Paul Vixie, 1996.
  58  */
  59 int
  60 strtoaddr(const char *src, void *dst)
  61 {
  62         uint32_t val;
  63         u_int digit;
  64         ptrdiff_t n;
  65         unsigned char c;
  66         u_int parts[4];
  67         u_int *pp = parts;
  68
  69         c = *src;
  70         for (;;) {
  71                 /*
  72                  * Collect number up to ``.''.
  73                  * Values are specified as for C:
  74                  * 0x=hex, 0=octal, isdigit=decimal.
  75                  */
  76                 if (!isdigit(c))
  77                         return (0);
  78                 val = 0;
  79                 if (c == '0') {
  80                         c = *++src;
  81                         if (c == 'x' || c == 'X')
  82                                 return (0);
  83                         else if (isdigit(c) && c != '9')
  84                                 return (0);
  85                 }
  86                 for (;;) {
  87                         if (isdigit(c)) {
  88                                 digit = c - '0';
  89                                 if (digit >= 10)
  90                                         break;
  91                                 val = (val * 10) + digit;
  92                                 c = *++src;
  93                         } else
  94                                 break;
  95                 }
  96                 if (c == '.') {
  97                         /*
  98                          * Internet format:
  99                          *      a.b.c.d
 100                          *      a.b.c   (with c treated as 16 bits)
 101                          *      a.b     (with b treated as 24 bits)
 102                          *      a       (with a treated as 32 bits)
 103                          */
 104                         if (pp >= parts + 3)
 105                                 return (0);
 106                         *pp++ = val;
 107                         c = *++src;
 108                 } else
 109                         break;
 110         }
 111         /*
 112          * Check for trailing characters.
 113          */
 114         if (c != '\0' && !isspace(c))
 115                 return (0);
 116         /*
 117          * Find the number of parts specified.
 118          * It must be 4; we only support dotted quads, we don't
 119          * support shorthand.
 120          */
 121         n = pp - parts + 1;
 122         if (n != 4)
 123                 return (0);
 124         /*
 125          * parts[0-2] were set to the first 3 parts of the address;
 126          * val was set to the 4th part.
 127          *
 128          * Check if any part is bigger than 255.
 129          */
 130         if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
 131                 return (0);
 132         /*
 133          * Add the other three parts to val.
 134          */
 135         val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 136         if (dst) {
 137                 val = htonl(val);
 138                 memcpy(dst, &val, NS_INADDRSZ);
 139         }
 140         return (1);
 141 }
 142
 143 /* int
 144  * strtoaddr6(src, dst)
 145  *      convert presentation level IPv6 address to network order binary form.
 146  * return:
 147  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 148  * notice:
 149  *      (1) does not touch `dst' unless it's returning 1.
 150  *      (2) :: in a full address is silently ignored.
 151  * credit:
 152  *      inspired by Mark Andrews.
 153  * author:
 154  *      Paul Vixie, 1996.
 155  */
 156 int
 157 strtoaddr6(const char *src, void *dst)
 158 {
 159         static const char xdigits_l[] = "0123456789abcdef",
 160                           xdigits_u[] = "0123456789ABCDEF";
 161         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 162         const char *xdigits, *curtok;
 163         int ch, seen_xdigits;
 164         u_int val;
 165
 166         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 167         endp = tp + NS_IN6ADDRSZ;
 168         colonp = NULL;
 169         /* Leading :: requires some special handling. */
 170         if (*src == ':')
 171                 if (*++src != ':')
 172                         return (0);
 173         curtok = src;
 174         seen_xdigits = 0;
 175         val = 0;
 176         while ((ch = *src++) != '\0') {
 177                 const char *pch;
 178
 179                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 180                         pch = strchr((xdigits = xdigits_u), ch);
 181                 if (pch != NULL) {
 182                         val <<= 4;
 183                         val |= (int)(pch - xdigits);
 184                         if (++seen_xdigits > 4)
 185                                 return (0);
 186                         continue;
 187                 }
 188                 if (ch == ':') {
 189                         curtok = src;
 190                         if (!seen_xdigits) {
 191                                 if (colonp)
 192                                         return (0);
 193                                 colonp = tp;
 194                                 continue;
 195                         } else if (*src == '\0')
 196                                 return (0);
 197                         if (tp + NS_INT16SZ > endp)
 198                                 return (0);
 199                         *tp++ = (u_char) (val >> 8) & 0xff;
 200                         *tp++ = (u_char) val & 0xff;
 201                         seen_xdigits = 0;
 202                         val = 0;
 203                         continue;
 204                 }
 205                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 206                     strtoaddr(curtok, tp) > 0) {
 207                         tp += NS_INADDRSZ;
 208                         seen_xdigits = 0;
 209                         break;  /*%< '\\0' was seen by strtoaddr(). */
 210                 }
 211                 return (0);
 212         }
 213         if (seen_xdigits) {
 214                 if (tp + NS_INT16SZ > endp)
 215                         return (0);
 216                 *tp++ = (u_char) (val >> 8) & 0xff;
 217                 *tp++ = (u_char) val & 0xff;
 218         }
 219         if (colonp != NULL) {
 220                 /*
 221                  * Since some memmove()'s erroneously fail to handle
 222                  * overlapping regions, we'll do the shift by hand.
 223                  */
 224                 const ptrdiff_t n = tp - colonp;
 225                 int i;
 226
 227                 if (tp == endp)
 228                         return (0);
 229                 for (i = 1; i <= n; i++) {
 230                         endp[- i] = colonp[n - i];
 231                         colonp[n - i] = 0;
 232                 }
 233                 tp = endp;
 234         }
 235         if (tp != endp)
 236                 return (0);
 237         memcpy(dst, tmp, NS_IN6ADDRSZ);
 238         return (1);
 239 }