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 #include <config.h>
  19
  20 #include "netdissect-stdinc.h"
  21 #include <stddef.h>
  22 #include <string.h>
  23
  24 #include "netdissect-ctype.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 /* int
  46  * strtoaddr(src, dst)
  47  *      convert presentation level IPv4 address to network order binary form.
  48  * return:
  49  *      1 if `src' is a valid input, else 0.
  50  * notice:
  51  *      does not touch `dst' unless it's returning 1.
  52  * author:
  53  *      Paul Vixie, 1996.
  54  */
  55 int
  56 strtoaddr(const char *src, void *dst)
  57 {
  58         uint32_t val;
  59         u_int digit;
  60         ptrdiff_t n;
  61         unsigned char c;
  62         u_int parts[4];
  63         u_int *pp = parts;
  64
  65         c = *src;
  66         for (;;) {
  67                 /*
  68                  * Collect number up to ``.''.
  69                  * Values are specified as for C:
  70                  * 0x=hex, 0=octal, isdigit=decimal.
  71                  */
  72                 if (!ND_ASCII_ISDIGIT(c))
  73                         return (0);
  74                 val = 0;
  75                 if (c == '0') {
  76                         c = *++src;
  77                         if (c == 'x' || c == 'X')
  78                                 return (0);
  79                         else if (ND_ASCII_ISDIGIT(c) && c != '9')
  80                                 return (0);
  81                 }
  82                 for (;;) {
  83                         if (ND_ASCII_ISDIGIT(c)) {
  84                                 digit = c - '0';
  85                                 val = (val * 10) + digit;
  86                                 c = *++src;
  87                         } else
  88                                 break;
  89                 }
  90                 if (c == '.') {
  91                         /*
  92                          * Internet format:
  93                          *      a.b.c.d
  94                          *      a.b.c   (with c treated as 16 bits)
  95                          *      a.b     (with b treated as 24 bits)
  96                          *      a       (with a treated as 32 bits)
  97                          */
  98                         if (pp >= parts + 3)
  99                                 return (0);
 100                         *pp++ = val;
 101                         c = *++src;
 102                 } else
 103                         break;
 104         }
 105         /*
 106          * Check for trailing characters.
 107          */
 108         if (c != '\0' && c != ' ' && c != '\t')
 109                 return (0);
 110         /*
 111          * Find the number of parts specified.
 112          * It must be 4; we only support dotted quads, we don't
 113          * support shorthand.
 114          */
 115         n = pp - parts + 1;
 116         if (n != 4)
 117                 return (0);
 118         /*
 119          * parts[0-2] were set to the first 3 parts of the address;
 120          * val was set to the 4th part.
 121          *
 122          * Check if any part is bigger than 255.
 123          */
 124         if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
 125                 return (0);
 126         /*
 127          * Add the other three parts to val.
 128          */
 129         val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 130         if (dst) {
 131                 val = htonl(val);
 132                 memcpy(dst, &val, NS_INADDRSZ);
 133         }
 134         return (1);
 135 }
 136
 137 /* int
 138  * strtoaddr6(src, dst)
 139  *      convert presentation level IPv6 address to network order binary form.
 140  * return:
 141  *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 142  * notice:
 143  *      (1) does not touch `dst' unless it's returning 1.
 144  *      (2) :: in a full address is silently ignored.
 145  * credit:
 146  *      inspired by Mark Andrews.
 147  * author:
 148  *      Paul Vixie, 1996.
 149  */
 150 int
 151 strtoaddr6(const char *src, void *dst)
 152 {
 153         static const char xdigits_l[] = "0123456789abcdef",
 154                           xdigits_u[] = "0123456789ABCDEF";
 155         u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
 156         const char *xdigits, *curtok;
 157         int ch, seen_xdigits;
 158         u_int val;
 159
 160         memset((tp = tmp), '\0', NS_IN6ADDRSZ);
 161         endp = tp + NS_IN6ADDRSZ;
 162         colonp = NULL;
 163         /* Leading :: requires some special handling. */
 164         if (*src == ':')
 165                 if (*++src != ':')
 166                         return (0);
 167         curtok = src;
 168         seen_xdigits = 0;
 169         val = 0;
 170         while ((ch = *src++) != '\0') {
 171                 const char *pch;
 172
 173                 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
 174                         pch = strchr((xdigits = xdigits_u), ch);
 175                 if (pch != NULL) {
 176                         val <<= 4;
 177                         val |= (int)(pch - xdigits);
 178                         if (++seen_xdigits > 4)
 179                                 return (0);
 180                         continue;
 181                 }
 182                 if (ch == ':') {
 183                         curtok = src;
 184                         if (!seen_xdigits) {
 185                                 if (colonp)
 186                                         return (0);
 187                                 colonp = tp;
 188                                 continue;
 189                         } else if (*src == '\0')
 190                                 return (0);
 191                         if (tp + NS_INT16SZ > endp)
 192                                 return (0);
 193                         *tp++ = (u_char) (val >> 8) & 0xff;
 194                         *tp++ = (u_char) val & 0xff;
 195                         seen_xdigits = 0;
 196                         val = 0;
 197                         continue;
 198                 }
 199                 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
 200                     strtoaddr(curtok, tp) > 0) {
 201                         tp += NS_INADDRSZ;
 202                         seen_xdigits = 0;
 203                         break;  /*%< '\\0' was seen by strtoaddr(). */
 204                 }
 205                 return (0);
 206         }
 207         if (seen_xdigits) {
 208                 if (tp + NS_INT16SZ > endp)
 209                         return (0);
 210                 *tp++ = (u_char) (val >> 8) & 0xff;
 211                 *tp++ = (u_char) val & 0xff;
 212         }
 213         if (colonp != NULL) {
 214                 /*
 215                  * Since some memmove()'s erroneously fail to handle
 216                  * overlapping regions, we'll do the shift by hand.
 217                  */
 218                 const ptrdiff_t n = tp - colonp;
 219                 int i;
 220
 221                 if (tp == endp)
 222                         return (0);
 223                 for (i = 1; i <= n; i++) {
 224                         endp[- i] = colonp[n - i];
 225                         colonp[n - i] = 0;
 226                 }
 227                 tp = endp;
 228         }
 229         if (tp != endp)
 230                 return (0);
 231         memcpy(dst, tmp, NS_IN6ADDRSZ);
 232         return (1);
 233 }