The Tcpdump Group git mirrors - tcpdump/blob - 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 u_int16_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          * Concoct the address according to
 118          * the number of parts specified.
 119          */
 120         n = pp - parts + 1;
 121         /* Takes dotted-quad only.  it does not take shorthand. */
 122         if (n != 4)
 123                 return (0);
 124         switch (n) {
 125
 126         case 0:
 127                 return (0);             /* initial nondigit */
 128
 129         case 1:                         /* a -- 32 bits */
 130                 break;
 131
 132         case 2:                         /* a.b -- 8.24 bits */
 133                 if (parts[0] > 0xff || val > 0xffffff)
 134                         return (0);
 135                 val |= parts[0] << 24;
 136                 break;
 137
 138         case 3:                         /* a.b.c -- 8.8.16 bits */
 139                 if ((parts[0] | parts[1]) > 0xff || val > 0xffff)
 140                         return (0);
 141                 val |= (parts[0] << 24) | (parts[1] << 16);
 142                 break;
 143
 144         case 4:                         /* a.b.c.d -- 8.8.8.8 bits */
 145                 if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
 146                         return (0);
 147                 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 148                 break;
 149         }
 150         if (dst) {
 151                 val = htonl(val);
 152                 memcpy(dst, &val, NS_INADDRSZ);
 153         }
 154         return (1);
 155 }
 156
 157 /* int
 158  * strtoaddr6(src, dst)
 159  *      convert presentation level IPv6 address to network order binary form.
 160  * return:
 161  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 162  * notice:
 163  *      (1) does not touch `dst' unless it's returning 1.
 164  *      (2) :: in a full address is silently ignored.
 165  * credit:
 166  *      inspired by Mark Andrews.
 167  * author:
 168  *      Paul Vixie, 1996.
 169  */
 170 int
 171 strtoaddr6(const char *src, void *dst)
 172 {
 173         static const char xdigits_l[] = "0123456789abcdef",
 174                           xdigits_u[] = "0123456789ABCDEF";
 175         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 176         const char *xdigits, *curtok;
 177         int ch, seen_xdigits;
 178         u_int val;
 179
 180         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 181         endp = tp + NS_IN6ADDRSZ;
 182         colonp = NULL;
 183         /* Leading :: requires some special handling. */
 184         if (*src == ':')
 185                 if (*++src != ':')
 186                         return (0);
 187         curtok = src;
 188         seen_xdigits = 0;
 189         val = 0;
 190         while ((ch = *src++) != '\0') {
 191                 const char *pch;
 192
 193                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 194                         pch = strchr((xdigits = xdigits_u), ch);
 195                 if (pch != NULL) {
 196                         val <<= 4;
 197                         val |= (int)(pch - xdigits);
 198                         if (++seen_xdigits > 4)
 199                                 return (0);
 200                         continue;
 201                 }
 202                 if (ch == ':') {
 203                         curtok = src;
 204                         if (!seen_xdigits) {
 205                                 if (colonp)
 206                                         return (0);
 207                                 colonp = tp;
 208                                 continue;
 209                         } else if (*src == '\0')
 210                                 return (0);
 211                         if (tp + NS_INT16SZ > endp)
 212                                 return (0);
 213                         *tp++ = (u_char) (val >> 8) & 0xff;
 214                         *tp++ = (u_char) val & 0xff;
 215                         seen_xdigits = 0;
 216                         val = 0;
 217                         continue;
 218                 }
 219                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 220                     strtoaddr(curtok, tp) > 0) {
 221                         tp += NS_INADDRSZ;
 222                         seen_xdigits = 0;
 223                         break;  /*%< '\\0' was seen by strtoaddr(). */
 224                 }
 225                 return (0);
 226         }
 227         if (seen_xdigits) {
 228                 if (tp + NS_INT16SZ > endp)
 229                         return (0);
 230                 *tp++ = (u_char) (val >> 8) & 0xff;
 231                 *tp++ = (u_char) val & 0xff;
 232         }
 233         if (colonp != NULL) {
 234                 /*
 235                  * Since some memmove()'s erroneously fail to handle
 236                  * overlapping regions, we'll do the shift by hand.
 237                  */
 238                 const ptrdiff_t n = tp - colonp;
 239                 int i;
 240
 241                 if (tp == endp)
 242                         return (0);
 243                 for (i = 1; i <= n; i++) {
 244                         endp[- i] = colonp[n - i];
 245                         colonp[n - i] = 0;
 246                 }
 247                 tp = endp;
 248         }
 249         if (tp != endp)
 250                 return (0);
 251         memcpy(dst, tmp, NS_IN6ADDRSZ);
 252         return (1);
 253 }