src/backend/utils/adt/inet_net_ntop.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  *        $PostgreSQL$
  18  */
  19
  20 #if defined(LIBC_SCCS) && !defined(lint)
  21 static const char rcsid[] = "Id: inet_net_ntop.c,v 1.1.2.2 2004/03/09 09:17:27 marka Exp $";
  22 #endif
  23
  24 #include "postgres.h"
  25
  26 #include <sys/types.h>
  27 #include <sys/socket.h>
  28 #include <netinet/in.h>
  29 #include <arpa/inet.h>
  30
  31 #include "utils/builtins.h"
  32 #include "utils/inet.h"
  33
  34
  35 #define NS_IN6ADDRSZ 16
  36 #define NS_INT16SZ 2
  37
  38 #ifdef SPRINTF_CHAR
  39 #define SPRINTF(x) strlen(sprintf/**/x)
  40 #else
  41 #define SPRINTF(x) ((size_t)sprintf x)
  42 #endif
  43
  44 static char *inet_net_ntop_ipv4(const u_char *src, int bits,
  45                                    char *dst, size_t size);
  46 static char *inet_cidr_ntop_ipv4(const u_char *src, int bits,
  47                                         char *dst, size_t size);
  48 static char *inet_net_ntop_ipv6(const u_char *src, int bits,
  49                                    char *dst, size_t size);
  50 static char *inet_cidr_ntop_ipv6(const u_char *src, int bits,
  51                                         char *dst, size_t size);
  52
  53 /*
  54  * char *
  55  * inet_cidr_ntop(af, src, bits, dst, size)
  56  *      convert network number from network to presentation format.
  57  *      generates CIDR style result always.
  58  * return:
  59  *      pointer to dst, or NULL if an error occurred (check errno).
  60  * author:
  61  *      Paul Vixie (ISC), July 1996
  62  */
  63 char *
  64 inet_cidr_ntop(int af, const void *src, int bits, char *dst, size_t size)
  65 {
  66         switch (af)
  67         {
  68                 case PGSQL_AF_INET:
  69                         return (inet_cidr_ntop_ipv4(src, bits, dst, size));
  70                 case PGSQL_AF_INET6:
  71                         return (inet_cidr_ntop_ipv6(src, bits, dst, size));
  72                 default:
  73                         errno = EAFNOSUPPORT;
  74                         return (NULL);
  75         }
  76 }
  77
  78
  79 /*
  80  * static char *
  81  * inet_cidr_ntop_ipv4(src, bits, dst, size)
  82  *      convert IPv4 network number from network to presentation format.
  83  *      generates CIDR style result always.
  84  * return:
  85  *      pointer to dst, or NULL if an error occurred (check errno).
  86  * note:
  87  *      network byte order assumed.  this means 192.5.5.240/28 has
  88  *      0b11110000 in its fourth octet.
  89  * author:
  90  *      Paul Vixie (ISC), July 1996
  91  */
  92 static char *
  93 inet_cidr_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
  94 {
  95         char       *odst = dst;
  96         char       *t;
  97         u_int           m;
  98         int                     b;
  99
 100         if (bits < 0 || bits > 32)
 101         {
 102                 errno = EINVAL;
 103                 return (NULL);
 104         }
 105
 106         if (bits == 0)
 107         {
 108                 if (size < sizeof "0")
 109                         goto emsgsize;
 110                 *dst++ = '0';
 111                 size--;
 112                 *dst = '\0';
 113         }
 114
 115         /* Format whole octets. */
 116         for (b = bits / 8; b > 0; b--)
 117         {
 118                 if (size <= sizeof "255.")
 119                         goto emsgsize;
 120                 t = dst;
 121                 dst += SPRINTF((dst, "%u", *src++));
 122                 if (b > 1)
 123                 {
 124                         *dst++ = '.';
 125                         *dst = '\0';
 126                 }
 127                 size -= (size_t) (dst - t);
 128         }
 129
 130         /* Format partial octet. */
 131         b = bits % 8;
 132         if (b > 0)
 133         {
 134                 if (size <= sizeof ".255")
 135                         goto emsgsize;
 136                 t = dst;
 137                 if (dst != odst)
 138                         *dst++ = '.';
 139                 m = ((1 << b) - 1) << (8 - b);
 140                 dst += SPRINTF((dst, "%u", *src & m));
 141                 size -= (size_t) (dst - t);
 142         }
 143
 144         /* Format CIDR /width. */
 145         if (size <= sizeof "/32")
 146                 goto emsgsize;
 147         dst += SPRINTF((dst, "/%u", bits));
 148         return (odst);
 149
 150 emsgsize:
 151         errno = EMSGSIZE;
 152         return (NULL);
 153 }
 154
 155 /*
 156  * static char *
 157  * inet_cidr_ntop_ipv6(src, bits, fakebits, dst, size)
 158  *      convert IPv6 network number from network to presentation format.
 159  *      generates CIDR style result always. Picks the shortest representation
 160  *      unless the IP is really IPv4.
 161  *      always prints specified number of bits (bits).
 162  * return:
 163  *      pointer to dst, or NULL if an error occurred (check errno).
 164  * note:
 165  *      network byte order assumed.  this means 192.5.5.240/28 has
 166  *      0x11110000 in its fourth octet.
 167  * author:
 168  *      Vadim Kogan (UCB), June 2001
 169  *      Original version (IPv4) by Paul Vixie (ISC), July 1996
 170  */
 171
 172 static char *
 173 inet_cidr_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
 174 {
 175         u_int           m;
 176         int                     b;
 177         int                     p;
 178         int                     zero_s,
 179                                 zero_l,
 180                                 tmp_zero_s,
 181                                 tmp_zero_l;
 182         int                     i;
 183         int                     is_ipv4 = 0;
 184         unsigned char inbuf[16];
 185         char            outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
 186         char       *cp;
 187         int                     words;
 188         u_char     *s;
 189
 190         if (bits < 0 || bits > 128)
 191         {
 192                 errno = EINVAL;
 193                 return (NULL);
 194         }
 195
 196         cp = outbuf;
 197
 198         if (bits == 0)
 199         {
 200                 *cp++ = ':';
 201                 *cp++ = ':';
 202                 *cp = '\0';
 203         }
 204         else
 205         {
 206                 /* Copy src to private buffer.  Zero host part. */
 207                 p = (bits + 7) / 8;
 208                 memcpy(inbuf, src, p);
 209                 memset(inbuf + p, 0, 16 - p);
 210                 b = bits % 8;
 211                 if (b != 0)
 212                 {
 213                         m = ~0 << (8 - b);
 214                         inbuf[p - 1] &= m;
 215                 }
 216
 217                 s = inbuf;
 218
 219                 /* how many words need to be displayed in output */
 220                 words = (bits + 15) / 16;
 221                 if (words == 1)
 222                         words = 2;
 223
 224                 /* Find the longest substring of zero's */
 225                 zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
 226                 for (i = 0; i < (words * 2); i += 2)
 227                 {
 228                         if ((s[i] | s[i + 1]) == 0)
 229                         {
 230                                 if (tmp_zero_l == 0)
 231                                         tmp_zero_s = i / 2;
 232                                 tmp_zero_l++;
 233                         }
 234                         else
 235                         {
 236                                 if (tmp_zero_l && zero_l < tmp_zero_l)
 237                                 {
 238                                         zero_s = tmp_zero_s;
 239                                         zero_l = tmp_zero_l;
 240                                         tmp_zero_l = 0;
 241                                 }
 242                         }
 243                 }
 244
 245                 if (tmp_zero_l && zero_l < tmp_zero_l)
 246                 {
 247                         zero_s = tmp_zero_s;
 248                         zero_l = tmp_zero_l;
 249                 }
 250
 251                 if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
 252                                                   ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
 253                                                    ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
 254                         is_ipv4 = 1;
 255
 256                 /* Format whole words. */
 257                 for (p = 0; p < words; p++)
 258                 {
 259                         if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l)
 260                         {
 261                                 /* Time to skip some zeros */
 262                                 if (p == zero_s)
 263                                         *cp++ = ':';
 264                                 if (p == words - 1)
 265                                         *cp++ = ':';
 266                                 s++;
 267                                 s++;
 268                                 continue;
 269                         }
 270
 271                         if (is_ipv4 && p > 5)
 272                         {
 273                                 *cp++ = (p == 6) ? ':' : '.';
 274                                 cp += SPRINTF((cp, "%u", *s++));
 275                                 /* we can potentially drop the last octet */
 276                                 if (p != 7 || bits > 120)
 277                                 {
 278                                         *cp++ = '.';
 279                                         cp += SPRINTF((cp, "%u", *s++));
 280                                 }
 281                         }
 282                         else
 283                         {
 284                                 if (cp != outbuf)
 285                                         *cp++ = ':';
 286                                 cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
 287                                 s += 2;
 288                         }
 289                 }
 290         }
 291         /* Format CIDR /width. */
 292         (void) SPRINTF((cp, "/%u", bits));
 293         if (strlen(outbuf) + 1 > size)
 294                 goto emsgsize;
 295         strcpy(dst, outbuf);
 296
 297         return (dst);
 298
 299 emsgsize:
 300         errno = EMSGSIZE;
 301         return (NULL);
 302 }
 303
 304
 305 /*
 306  * char *
 307  * inet_net_ntop(af, src, bits, dst, size)
 308  *      convert host/network address from network to presentation format.
 309  *      "src"'s size is determined from its "af".
 310  * return:
 311  *      pointer to dst, or NULL if an error occurred (check errno).
 312  * note:
 313  *      192.5.5.1/28 has a nonzero host part, which means it isn't a network
 314  *      as called for by inet_net_pton() but it can be a host address with
 315  *      an included netmask.
 316  * author:
 317  *      Paul Vixie (ISC), October 1998
 318  */
 319 char *
 320 inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size)
 321 {
 322         switch (af)
 323         {
 324                 case PGSQL_AF_INET:
 325                         return (inet_net_ntop_ipv4(src, bits, dst, size));
 326                 case PGSQL_AF_INET6:
 327                         return (inet_net_ntop_ipv6(src, bits, dst, size));
 328                 default:
 329                         errno = EAFNOSUPPORT;
 330                         return (NULL);
 331         }
 332 }
 333
 334 /*
 335  * static char *
 336  * inet_net_ntop_ipv4(src, bits, dst, size)
 337  *      convert IPv4 network address from network to presentation format.
 338  *      "src"'s size is determined from its "af".
 339  * return:
 340  *      pointer to dst, or NULL if an error occurred (check errno).
 341  * note:
 342  *      network byte order assumed.  this means 192.5.5.240/28 has
 343  *      0b11110000 in its fourth octet.
 344  * author:
 345  *      Paul Vixie (ISC), October 1998
 346  */
 347 static char *
 348 inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
 349 {
 350         char       *odst = dst;
 351         char       *t;
 352         int                     len = 4;
 353         int                     b;
 354
 355         if (bits < 0 || bits > 32)
 356         {
 357                 errno = EINVAL;
 358                 return (NULL);
 359         }
 360
 361         /* Always format all four octets, regardless of mask length. */
 362         for (b = len; b > 0; b--)
 363         {
 364                 if (size <= sizeof ".255")
 365                         goto emsgsize;
 366                 t = dst;
 367                 if (dst != odst)
 368                         *dst++ = '.';
 369                 dst += SPRINTF((dst, "%u", *src++));
 370                 size -= (size_t) (dst - t);
 371         }
 372
 373         /* don't print masklen if 32 bits */
 374         if (bits != 32)
 375         {
 376                 if (size <= sizeof "/32")
 377                         goto emsgsize;
 378                 dst += SPRINTF((dst, "/%u", bits));
 379         }
 380
 381         return (odst);
 382
 383 emsgsize:
 384         errno = EMSGSIZE;
 385         return (NULL);
 386 }
 387
 388 static int
 389 decoct(const u_char *src, int bytes, char *dst, size_t size)
 390 {
 391         char       *odst = dst;
 392         char       *t;
 393         int                     b;
 394
 395         for (b = 1; b <= bytes; b++)
 396         {
 397                 if (size <= sizeof "255.")
 398                         return (0);
 399                 t = dst;
 400                 dst += SPRINTF((dst, "%u", *src++));
 401                 if (b != bytes)
 402                 {
 403                         *dst++ = '.';
 404                         *dst = '\0';
 405                 }
 406                 size -= (size_t) (dst - t);
 407         }
 408         return (dst - odst);
 409 }
 410
 411 static char *
 412 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
 413 {
 414         /*
 415          * Note that int32_t and int16_t need only be "at least" large enough to
 416          * contain a value of the specified size.  On some systems, like Crays,
 417          * there is no such thing as an integer variable with 16 bits. Keep this
 418          * in mind if you think this function should have been coded to use
 419          * pointer overlays.  All the world's not a VAX.
 420          */
 421         char            tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255/128"];
 422         char       *tp;
 423         struct
 424         {
 425                 int                     base,
 426                                         len;
 427         }                       best, cur;
 428         u_int           words[NS_IN6ADDRSZ / NS_INT16SZ];
 429         int                     i;
 430
 431         if ((bits < -1) || (bits > 128))
 432         {
 433                 errno = EINVAL;
 434                 return (NULL);
 435         }
 436
 437         /*
 438          * Preprocess: Copy the input (bytewise) array into a wordwise array. Find
 439          * the longest run of 0x00's in src[] for :: shorthanding.
 440          */
 441         memset(words, '\0', sizeof words);
 442         for (i = 0; i < NS_IN6ADDRSZ; i++)
 443                 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
 444         best.base = -1;
 445         cur.base = -1;
 446         best.len = 0;
 447         cur.len = 0;
 448         for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
 449         {
 450                 if (words[i] == 0)
 451                 {
 452                         if (cur.base == -1)
 453                                 cur.base = i, cur.len = 1;
 454                         else
 455                                 cur.len++;
 456                 }
 457                 else
 458                 {
 459                         if (cur.base != -1)
 460                         {
 461                                 if (best.base == -1 || cur.len > best.len)
 462                                         best = cur;
 463                                 cur.base = -1;
 464                         }
 465                 }
 466         }
 467         if (cur.base != -1)
 468         {
 469                 if (best.base == -1 || cur.len > best.len)
 470                         best = cur;
 471         }
 472         if (best.base != -1 && best.len < 2)
 473                 best.base = -1;
 474
 475         /*
 476          * Format the result.
 477          */
 478         tp = tmp;
 479         for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
 480         {
 481                 /* Are we inside the best run of 0x00's? */
 482                 if (best.base != -1 && i >= best.base &&
 483                         i < (best.base + best.len))
 484                 {
 485                         if (i == best.base)
 486                                 *tp++ = ':';
 487                         continue;
 488                 }
 489                 /* Are we following an initial run of 0x00s or any real hex? */
 490                 if (i != 0)
 491                         *tp++ = ':';
 492                 /* Is this address an encapsulated IPv4? */
 493                 if (i == 6 && best.base == 0 && (best.len == 6 ||
 494                                                                          (best.len == 7 && words[7] != 0x0001) ||
 495                                                                           (best.len == 5 && words[5] == 0xffff)))
 496                 {
 497                         int                     n;
 498
 499                         n = decoct(src + 12, 4, tp, sizeof tmp - (tp - tmp));
 500                         if (n == 0)
 501                         {
 502                                 errno = EMSGSIZE;
 503                                 return (NULL);
 504                         }
 505                         tp += strlen(tp);
 506                         break;
 507                 }
 508                 tp += SPRINTF((tp, "%x", words[i]));
 509         }
 510
 511         /* Was it a trailing run of 0x00's? */
 512         if (best.base != -1 && (best.base + best.len) ==
 513                 (NS_IN6ADDRSZ / NS_INT16SZ))
 514                 *tp++ = ':';
 515         *tp = '\0';
 516
 517         if (bits != -1 && bits != 128)
 518                 tp += SPRINTF((tp, "/%u", bits));
 519
 520         /*
 521          * Check for overflow, copy, and we're done.
 522          */
 523         if ((size_t) (tp - tmp) > size)
 524         {
 525                 errno = EMSGSIZE;
 526                 return (NULL);
 527         }
 528         strcpy(dst, tmp);
 529         return (dst);
 530 }