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      1 
      2 /*
      3  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
      4  * Copyright (c) 1996,1999 by Internet Software Consortium.
      5  *
      6  * Permission to use, copy, modify, and distribute this software for any
      7  * purpose with or without fee is hereby granted, provided that the above
      8  * copyright notice and this permission notice appear in all copies.
      9  *
     10  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
     11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     12  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
     13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
     16  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     17  */
     18 
     19 #include "ares_setup.h"
     20 
     21 #ifdef HAVE_SYS_SOCKET_H
     22 #  include <sys/socket.h>
     23 #endif
     24 #ifdef HAVE_NETINET_IN_H
     25 #  include <netinet/in.h>
     26 #endif
     27 #ifdef HAVE_ARPA_INET_H
     28 #  include <arpa/inet.h>
     29 #endif
     30 #ifdef HAVE_ARPA_NAMESER_H
     31 #  include <arpa/nameser.h>
     32 #else
     33 #  include "nameser.h"
     34 #endif
     35 #ifdef HAVE_ARPA_NAMESER_COMPAT_H
     36 #  include <arpa/nameser_compat.h>
     37 #endif
     38 
     39 #include <ctype.h>
     40 #include <stdio.h>
     41 #include <string.h>
     42 #include <stdlib.h>
     43 
     44 #include "ares.h"
     45 #include "ares_ipv6.h"
     46 #include "ares_nowarn.h"
     47 #include "inet_net_pton.h"
     48 
     49 
     50 const struct ares_in6_addr ares_in6addr_any = { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } };
     51 
     52 
     53 #ifndef HAVE_INET_NET_PTON
     54 
     55 /*
     56  * static int
     57  * inet_net_pton_ipv4(src, dst, size)
     58  *      convert IPv4 network number from presentation to network format.
     59  *      accepts hex octets, hex strings, decimal octets, and /CIDR.
     60  *      "size" is in bytes and describes "dst".
     61  * return:
     62  *      number of bits, either imputed classfully or specified with /CIDR,
     63  *      or -1 if some failure occurred (check errno).  ENOENT means it was
     64  *      not an IPv4 network specification.
     65  * note:
     66  *      network byte order assumed.  this means 192.5.5.240/28 has
     67  *      0b11110000 in its fourth octet.
     68  * note:
     69  *      On Windows we store the error in the thread errno, not
     70  *      in the winsock error code. This is to avoid loosing the
     71  *      actual last winsock error. So use macro ERRNO to fetch the
     72  *      errno this funtion sets when returning (-1), not SOCKERRNO.
     73  * author:
     74  *      Paul Vixie (ISC), June 1996
     75  */
     76 static int
     77 inet_net_pton_ipv4(const char *src, unsigned char *dst, size_t size)
     78 {
     79   static const char xdigits[] = "0123456789abcdef";
     80   static const char digits[] = "0123456789";
     81   int n, ch, tmp = 0, dirty, bits;
     82   const unsigned char *odst = dst;
     83 
     84   ch = *src++;
     85   if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
     86       && ISASCII(src[1])
     87       && ISXDIGIT(src[1])) {
     88     /* Hexadecimal: Eat nybble string. */
     89     if (!size)
     90       goto emsgsize;
     91     dirty = 0;
     92     src++;  /* skip x or X. */
     93     while ((ch = *src++) != '\0' && ISASCII(ch) && ISXDIGIT(ch)) {
     94       if (ISUPPER(ch))
     95         ch = tolower(ch);
     96       n = aresx_sztosi(strchr(xdigits, ch) - xdigits);
     97       if (dirty == 0)
     98         tmp = n;
     99       else
    100         tmp = (tmp << 4) | n;
    101       if (++dirty == 2) {
    102         if (!size--)
    103           goto emsgsize;
    104         *dst++ = (unsigned char) tmp;
    105         dirty = 0;
    106       }
    107     }
    108     if (dirty) {  /* Odd trailing nybble? */
    109       if (!size--)
    110         goto emsgsize;
    111       *dst++ = (unsigned char) (tmp << 4);
    112     }
    113   } else if (ISASCII(ch) && ISDIGIT(ch)) {
    114     /* Decimal: eat dotted digit string. */
    115     for (;;) {
    116       tmp = 0;
    117       do {
    118         n = aresx_sztosi(strchr(digits, ch) - digits);
    119         tmp *= 10;
    120         tmp += n;
    121         if (tmp > 255)
    122           goto enoent;
    123       } while ((ch = *src++) != '\0' &&
    124                ISASCII(ch) && ISDIGIT(ch));
    125       if (!size--)
    126         goto emsgsize;
    127       *dst++ = (unsigned char) tmp;
    128       if (ch == '\0' || ch == '/')
    129         break;
    130       if (ch != '.')
    131         goto enoent;
    132       ch = *src++;
    133       if (!ISASCII(ch) || !ISDIGIT(ch))
    134         goto enoent;
    135     }
    136   } else
    137     goto enoent;
    138 
    139   bits = -1;
    140   if (ch == '/' && ISASCII(src[0]) &&
    141       ISDIGIT(src[0]) && dst > odst) {
    142     /* CIDR width specifier.  Nothing can follow it. */
    143     ch = *src++;    /* Skip over the /. */
    144     bits = 0;
    145     do {
    146       n = aresx_sztosi(strchr(digits, ch) - digits);
    147       bits *= 10;
    148       bits += n;
    149       if (bits > 32)
    150         goto enoent;
    151     } while ((ch = *src++) != '\0' && ISASCII(ch) && ISDIGIT(ch));
    152     if (ch != '\0')
    153       goto enoent;
    154   }
    155 
    156   /* Firey death and destruction unless we prefetched EOS. */
    157   if (ch != '\0')
    158     goto enoent;
    159 
    160   /* If nothing was written to the destination, we found no address. */
    161   if (dst == odst)
    162     goto enoent;
    163   /* If no CIDR spec was given, infer width from net class. */
    164   if (bits == -1) {
    165     if (*odst >= 240)       /* Class E */
    166       bits = 32;
    167     else if (*odst >= 224)  /* Class D */
    168       bits = 8;
    169     else if (*odst >= 192)  /* Class C */
    170       bits = 24;
    171     else if (*odst >= 128)  /* Class B */
    172       bits = 16;
    173     else                    /* Class A */
    174       bits = 8;
    175     /* If imputed mask is narrower than specified octets, widen. */
    176     if (bits < ((dst - odst) * 8))
    177       bits = aresx_sztosi(dst - odst) * 8;
    178     /*
    179      * If there are no additional bits specified for a class D
    180      * address adjust bits to 4.
    181      */
    182     if (bits == 8 && *odst == 224)
    183       bits = 4;
    184   }
    185   /* Extend network to cover the actual mask. */
    186   while (bits > ((dst - odst) * 8)) {
    187     if (!size--)
    188       goto emsgsize;
    189     *dst++ = '\0';
    190   }
    191   return (bits);
    192 
    193   enoent:
    194   SET_ERRNO(ENOENT);
    195   return (-1);
    196 
    197   emsgsize:
    198   SET_ERRNO(EMSGSIZE);
    199   return (-1);
    200 }
    201 
    202 static int
    203 getbits(const char *src, int *bitsp)
    204 {
    205   static const char digits[] = "0123456789";
    206   int n;
    207   int val;
    208   char ch;
    209 
    210   val = 0;
    211   n = 0;
    212   while ((ch = *src++) != '\0') {
    213     const char *pch;
    214 
    215     pch = strchr(digits, ch);
    216     if (pch != NULL) {
    217       if (n++ != 0 && val == 0)       /* no leading zeros */
    218         return (0);
    219       val *= 10;
    220       val += aresx_sztosi(pch - digits);
    221       if (val > 128)                  /* range */
    222         return (0);
    223       continue;
    224     }
    225     return (0);
    226   }
    227   if (n == 0)
    228     return (0);
    229   *bitsp = val;
    230   return (1);
    231 }
    232 
    233 static int
    234 getv4(const char *src, unsigned char *dst, int *bitsp)
    235 {
    236   static const char digits[] = "0123456789";
    237   unsigned char *odst = dst;
    238   int n;
    239   unsigned int val;
    240   char ch;
    241 
    242   val = 0;
    243   n = 0;
    244   while ((ch = *src++) != '\0') {
    245     const char *pch;
    246 
    247     pch = strchr(digits, ch);
    248     if (pch != NULL) {
    249       if (n++ != 0 && val == 0)       /* no leading zeros */
    250         return (0);
    251       val *= 10;
    252       val += aresx_sztoui(pch - digits);
    253       if (val > 255)                  /* range */
    254         return (0);
    255       continue;
    256     }
    257     if (ch == '.' || ch == '/') {
    258       if (dst - odst > 3)             /* too many octets? */
    259         return (0);
    260       *dst++ = (unsigned char)val;
    261       if (ch == '/')
    262         return (getbits(src, bitsp));
    263       val = 0;
    264       n = 0;
    265       continue;
    266     }
    267     return (0);
    268   }
    269   if (n == 0)
    270     return (0);
    271   if (dst - odst > 3)             /* too many octets? */
    272     return (0);
    273   *dst = (unsigned char)val;
    274   return 1;
    275 }
    276 
    277 static int
    278 inet_net_pton_ipv6(const char *src, unsigned char *dst, size_t size)
    279 {
    280   static const char xdigits_l[] = "0123456789abcdef",
    281     xdigits_u[] = "0123456789ABCDEF";
    282   unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
    283   const char *xdigits, *curtok;
    284   int ch, saw_xdigit;
    285   unsigned int val;
    286   int digits;
    287   int bits;
    288   size_t bytes;
    289   int words;
    290   int ipv4;
    291 
    292   memset((tp = tmp), '\0', NS_IN6ADDRSZ);
    293   endp = tp + NS_IN6ADDRSZ;
    294   colonp = NULL;
    295   /* Leading :: requires some special handling. */
    296   if (*src == ':')
    297     if (*++src != ':')
    298       goto enoent;
    299   curtok = src;
    300   saw_xdigit = 0;
    301   val = 0;
    302   digits = 0;
    303   bits = -1;
    304   ipv4 = 0;
    305   while ((ch = *src++) != '\0') {
    306     const char *pch;
    307 
    308     if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
    309       pch = strchr((xdigits = xdigits_u), ch);
    310     if (pch != NULL) {
    311       val <<= 4;
    312       val |= aresx_sztoui(pch - xdigits);
    313       if (++digits > 4)
    314         goto enoent;
    315       saw_xdigit = 1;
    316       continue;
    317     }
    318     if (ch == ':') {
    319       curtok = src;
    320       if (!saw_xdigit) {
    321         if (colonp)
    322           goto enoent;
    323         colonp = tp;
    324         continue;
    325       } else if (*src == '\0')
    326         goto enoent;
    327       if (tp + NS_INT16SZ > endp)
    328         return (0);
    329       *tp++ = (unsigned char)((val >> 8) & 0xff);
    330       *tp++ = (unsigned char)(val & 0xff);
    331       saw_xdigit = 0;
    332       digits = 0;
    333       val = 0;
    334       continue;
    335     }
    336     if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
    337         getv4(curtok, tp, &bits) > 0) {
    338       tp += NS_INADDRSZ;
    339       saw_xdigit = 0;
    340       ipv4 = 1;
    341       break;  /* '\0' was seen by inet_pton4(). */
    342     }
    343     if (ch == '/' && getbits(src, &bits) > 0)
    344       break;
    345     goto enoent;
    346   }
    347   if (saw_xdigit) {
    348     if (tp + NS_INT16SZ > endp)
    349       goto enoent;
    350     *tp++ = (unsigned char)((val >> 8) & 0xff);
    351     *tp++ = (unsigned char)(val & 0xff);
    352   }
    353   if (bits == -1)
    354     bits = 128;
    355 
    356   words = (bits + 15) / 16;
    357   if (words < 2)
    358     words = 2;
    359   if (ipv4)
    360     words = 8;
    361   endp =  tmp + 2 * words;
    362 
    363   if (colonp != NULL) {
    364     /*
    365      * Since some memmove()'s erroneously fail to handle
    366      * overlapping regions, we'll do the shift by hand.
    367      */
    368     const ssize_t n = tp - colonp;
    369     ssize_t i;
    370 
    371     if (tp == endp)
    372       goto enoent;
    373     for (i = 1; i <= n; i++) {
    374       *(endp - i) = *(colonp + n - i);
    375       *(colonp + n - i) = 0;
    376     }
    377     tp = endp;
    378   }
    379   if (tp != endp)
    380     goto enoent;
    381 
    382   bytes = (bits + 7) / 8;
    383   if (bytes > size)
    384     goto emsgsize;
    385   memcpy(dst, tmp, bytes);
    386   return (bits);
    387 
    388   enoent:
    389   SET_ERRNO(ENOENT);
    390   return (-1);
    391 
    392   emsgsize:
    393   SET_ERRNO(EMSGSIZE);
    394   return (-1);
    395 }
    396 
    397 /*
    398  * int
    399  * inet_net_pton(af, src, dst, size)
    400  *      convert network number from presentation to network format.
    401  *      accepts hex octets, hex strings, decimal octets, and /CIDR.
    402  *      "size" is in bytes and describes "dst".
    403  * return:
    404  *      number of bits, either imputed classfully or specified with /CIDR,
    405  *      or -1 if some failure occurred (check errno).  ENOENT means it was
    406  *      not a valid network specification.
    407  * note:
    408  *      On Windows we store the error in the thread errno, not
    409  *      in the winsock error code. This is to avoid loosing the
    410  *      actual last winsock error. So use macro ERRNO to fetch the
    411  *      errno this funtion sets when returning (-1), not SOCKERRNO.
    412  * author:
    413  *      Paul Vixie (ISC), June 1996
    414  */
    415 int
    416 ares_inet_net_pton(int af, const char *src, void *dst, size_t size)
    417 {
    418   switch (af) {
    419   case AF_INET:
    420     return (inet_net_pton_ipv4(src, dst, size));
    421   case AF_INET6:
    422     return (inet_net_pton_ipv6(src, dst, size));
    423   default:
    424     SET_ERRNO(EAFNOSUPPORT);
    425     return (-1);
    426   }
    427 }
    428 
    429 #endif /* HAVE_INET_NET_PTON */
    430 
    431 #ifndef HAVE_INET_PTON
    432 int ares_inet_pton(int af, const char *src, void *dst)
    433 {
    434   int result;
    435   size_t size;
    436 
    437   if (af == AF_INET)
    438     size = sizeof(struct in_addr);
    439   else if (af == AF_INET6)
    440     size = sizeof(struct ares_in6_addr);
    441   else
    442   {
    443     SET_ERRNO(EAFNOSUPPORT);
    444     return -1;
    445   }
    446   result = ares_inet_net_pton(af, src, dst, size);
    447   if (result == -1 && ERRNO == ENOENT)
    448     return 0;
    449   return (result > -1 ? 1 : -1);
    450 }
    451 #endif
    452