resolv/ns_print.c

   1 /*
   2  * Copyright (c) 1996-1999 by Internet Software Consortium.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
   9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  15  * SOFTWARE.
  16  */
  17
  18 #if !defined(_LIBC) && !defined(lint)
  19 static const char rcsid[] = "$BINDId: ns_print.c,v 8.18 2000/02/29 05:48:12 vixie Exp $";
  20 #endif
  21
  22 /* Import. */
  23
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26
  27 #include <netinet/in.h>
  28 #include <arpa/nameser.h>
  29 #include <arpa/inet.h>
  30
  31 #include <assert.h>
  32 #include <errno.h>
  33 #include <resolv.h>
  34 #include <string.h>
  35 #include <ctype.h>
  36
  37 #ifdef SPRINTF_CHAR
  38 # define SPRINTF(x) strlen(sprintf/**/x)
  39 #else
  40 # define SPRINTF(x) ((size_t)sprintf x)
  41 #endif
  42
  43 /* Forward. */
  44
  45 static size_t   prune_origin(const char *name, const char *origin);
  46 static int      charstr(const u_char *rdata, const u_char *edata,
  47                         char **buf, size_t *buflen);
  48 static int      addname(const u_char *msg, size_t msglen,
  49                         const u_char **p, const char *origin,
  50                         char **buf, size_t *buflen);
  51 static void     addlen(size_t len, char **buf, size_t *buflen);
  52 static int      addstr(const char *src, size_t len,
  53                        char **buf, size_t *buflen);
  54 static int      addtab(size_t len, size_t target, int spaced,
  55                        char **buf, size_t *buflen);
  56
  57 /* Proto. */
  58
  59 #ifndef _LIBC
  60 u_int16_t       dst_s_dns_key_id(const u_char *, const int);
  61 #endif
  62
  63 /* Macros. */
  64
  65 #define T(x) \
  66         do { \
  67                 if ((x) < 0) \
  68                         return (-1); \
  69         } while (0)
  70
  71 /* Public. */
  72
  73 /*
  74  * int
  75  * ns_sprintrr(handle, rr, name_ctx, origin, buf, buflen)
  76  *      Convert an RR to presentation format.
  77  * return:
  78  *      Number of characters written to buf, or -1 (check errno).
  79  */
  80 int
  81 ns_sprintrr(const ns_msg *handle, const ns_rr *rr,
  82             const char *name_ctx, const char *origin,
  83             char *buf, size_t buflen)
  84 {
  85         int n;
  86
  87         n = ns_sprintrrf(ns_msg_base(*handle), ns_msg_size(*handle),
  88                          ns_rr_name(*rr), ns_rr_class(*rr), ns_rr_type(*rr),
  89                          ns_rr_ttl(*rr), ns_rr_rdata(*rr), ns_rr_rdlen(*rr),
  90                          name_ctx, origin, buf, buflen);
  91         return (n);
  92 }
  93
  94 /*
  95  * int
  96  * ns_sprintrrf(msg, msglen, name, class, type, ttl, rdata, rdlen,
  97  *             name_ctx, origin, buf, buflen)
  98  *      Convert the fields of an RR into presentation format.
  99  * return:
 100  *      Number of characters written to buf, or -1 (check errno).
 101  */
 102 int
 103 ns_sprintrrf(const u_char *msg, size_t msglen,
 104             const char *name, ns_class class, ns_type type,
 105             u_long ttl, const u_char *rdata, size_t rdlen,
 106             const char *name_ctx, const char *origin,
 107             char *buf, size_t buflen)
 108 {
 109         const char *obuf = buf;
 110         const u_char *edata = rdata + rdlen;
 111         int spaced = 0;
 112
 113         const char *comment;
 114         char tmp[100];
 115         int len, x;
 116
 117         /*
 118          * Owner.
 119          */
 120         if (name_ctx != NULL && ns_samename(name_ctx, name) == 1) {
 121                 T(addstr("\t\t\t", 3, &buf, &buflen));
 122         } else {
 123                 len = prune_origin(name, origin);
 124                 if (len == 0) {
 125                         T(addstr("@\t\t\t", 4, &buf, &buflen));
 126                 } else {
 127                         T(addstr(name, len, &buf, &buflen));
 128                         /* Origin not used or not root, and no trailing dot? */
 129                         if (((origin == NULL || origin[0] == '\0') ||
 130                             (origin[0] != '.' && origin[1] != '\0' &&
 131                             name[len] == '\0')) && name[len - 1] != '.') {
 132                                 T(addstr(".", 1, &buf, &buflen));
 133                                 len++;
 134                         }
 135                         T(spaced = addtab(len, 24, spaced, &buf, &buflen));
 136                 }
 137         }
 138
 139         /*
 140          * TTL, Class, Type.
 141          */
 142         T(x = ns_format_ttl(ttl, buf, buflen));
 143         addlen(x, &buf, &buflen);
 144         len = SPRINTF((tmp, " %s %s", p_class(class), p_type(type)));
 145         T(addstr(tmp, len, &buf, &buflen));
 146         T(spaced = addtab(x + len, 16, spaced, &buf, &buflen));
 147
 148         /*
 149          * RData.
 150          */
 151         switch (type) {
 152         case ns_t_a:
 153                 if (rdlen != NS_INADDRSZ)
 154                         goto formerr;
 155                 (void) inet_ntop(AF_INET, rdata, buf, buflen);
 156                 addlen(strlen(buf), &buf, &buflen);
 157                 break;
 158
 159         case ns_t_cname:
 160         case ns_t_mb:
 161         case ns_t_mg:
 162         case ns_t_mr:
 163         case ns_t_ns:
 164         case ns_t_ptr:
 165                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 166                 break;
 167
 168         case ns_t_hinfo:
 169         case ns_t_isdn:
 170                 /* First word. */
 171                 T(len = charstr(rdata, edata, &buf, &buflen));
 172                 if (len == 0)
 173                         goto formerr;
 174                 rdata += len;
 175                 T(addstr(" ", 1, &buf, &buflen));
 176
 177
 178                 /* Second word, optional in ISDN records. */
 179                 if (type == ns_t_isdn && rdata == edata)
 180                         break;
 181
 182                 T(len = charstr(rdata, edata, &buf, &buflen));
 183                 if (len == 0)
 184                         goto formerr;
 185                 rdata += len;
 186                 break;
 187
 188         case ns_t_soa: {
 189                 u_long t;
 190
 191                 /* Server name. */
 192                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 193                 T(addstr(" ", 1, &buf, &buflen));
 194
 195                 /* Administrator name. */
 196                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 197                 T(addstr(" (\n", 3, &buf, &buflen));
 198                 spaced = 0;
 199
 200                 if ((edata - rdata) != 5*NS_INT32SZ)
 201                         goto formerr;
 202
 203                 /* Serial number. */
 204                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 205                 T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
 206                 len = SPRINTF((tmp, "%lu", t));
 207                 T(addstr(tmp, len, &buf, &buflen));
 208                 T(spaced = addtab(len, 16, spaced, &buf, &buflen));
 209                 T(addstr("; serial\n", 9, &buf, &buflen));
 210                 spaced = 0;
 211
 212                 /* Refresh interval. */
 213                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 214                 T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
 215                 T(len = ns_format_ttl(t, buf, buflen));
 216                 addlen(len, &buf, &buflen);
 217                 T(spaced = addtab(len, 16, spaced, &buf, &buflen));
 218                 T(addstr("; refresh\n", 10, &buf, &buflen));
 219                 spaced = 0;
 220
 221                 /* Retry interval. */
 222                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 223                 T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
 224                 T(len = ns_format_ttl(t, buf, buflen));
 225                 addlen(len, &buf, &buflen);
 226                 T(spaced = addtab(len, 16, spaced, &buf, &buflen));
 227                 T(addstr("; retry\n", 8, &buf, &buflen));
 228                 spaced = 0;
 229
 230                 /* Expiry. */
 231                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 232                 T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
 233                 T(len = ns_format_ttl(t, buf, buflen));
 234                 addlen(len, &buf, &buflen);
 235                 T(spaced = addtab(len, 16, spaced, &buf, &buflen));
 236                 T(addstr("; expiry\n", 9, &buf, &buflen));
 237                 spaced = 0;
 238
 239                 /* Minimum TTL. */
 240                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 241                 T(addstr("\t\t\t\t\t", 5, &buf, &buflen));
 242                 T(len = ns_format_ttl(t, buf, buflen));
 243                 addlen(len, &buf, &buflen);
 244                 T(addstr(" )", 2, &buf, &buflen));
 245                 T(spaced = addtab(len, 16, spaced, &buf, &buflen));
 246                 T(addstr("; minimum\n", 10, &buf, &buflen));
 247
 248                 break;
 249             }
 250
 251         case ns_t_mx:
 252         case ns_t_afsdb:
 253         case ns_t_rt: {
 254                 u_int t;
 255
 256                 if (rdlen < NS_INT16SZ)
 257                         goto formerr;
 258
 259                 /* Priority. */
 260                 t = ns_get16(rdata);
 261                 rdata += NS_INT16SZ;
 262                 len = SPRINTF((tmp, "%u ", t));
 263                 T(addstr(tmp, len, &buf, &buflen));
 264
 265                 /* Target. */
 266                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 267
 268                 break;
 269             }
 270
 271         case ns_t_px: {
 272                 u_int t;
 273
 274                 if (rdlen < NS_INT16SZ)
 275                         goto formerr;
 276
 277                 /* Priority. */
 278                 t = ns_get16(rdata);
 279                 rdata += NS_INT16SZ;
 280                 len = SPRINTF((tmp, "%u ", t));
 281                 T(addstr(tmp, len, &buf, &buflen));
 282
 283                 /* Name1. */
 284                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 285                 T(addstr(" ", 1, &buf, &buflen));
 286
 287                 /* Name2. */
 288                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 289
 290                 break;
 291             }
 292
 293         case ns_t_x25:
 294                 T(len = charstr(rdata, edata, &buf, &buflen));
 295                 if (len == 0)
 296                         goto formerr;
 297                 rdata += len;
 298                 break;
 299
 300         case ns_t_txt:
 301                 while (rdata < edata) {
 302                         T(len = charstr(rdata, edata, &buf, &buflen));
 303                         if (len == 0)
 304                                 goto formerr;
 305                         rdata += len;
 306                         if (rdata < edata)
 307                                 T(addstr(" ", 1, &buf, &buflen));
 308                 }
 309                 break;
 310
 311         case ns_t_nsap: {
 312                 /* 2*255 for hex digits, 128 for '.' and '\0', 2 for
 313                    0x if inet_nsap_ntoa starts using it.  */
 314                 char t[255*2 + 128 + 2];
 315
 316                 (void) inet_nsap_ntoa(rdlen, rdata, t);
 317                 T(addstr(t, strlen(t), &buf, &buflen));
 318                 break;
 319             }
 320
 321         case ns_t_aaaa:
 322                 if (rdlen != NS_IN6ADDRSZ)
 323                         goto formerr;
 324                 (void) inet_ntop(AF_INET6, rdata, buf, buflen);
 325                 addlen(strlen(buf), &buf, &buflen);
 326                 break;
 327
 328         case ns_t_loc: {
 329                 char t[255];
 330
 331                 /* XXX protocol format checking? */
 332                 (void) loc_ntoa(rdata, t);
 333                 T(addstr(t, strlen(t), &buf, &buflen));
 334                 break;
 335             }
 336
 337         case ns_t_naptr: {
 338                 u_int order, preference;
 339                 char t[50];
 340
 341                 if (rdlen < 2*NS_INT16SZ)
 342                         goto formerr;
 343
 344                 /* Order, Precedence. */
 345                 order = ns_get16(rdata);        rdata += NS_INT16SZ;
 346                 preference = ns_get16(rdata);   rdata += NS_INT16SZ;
 347                 len = SPRINTF((t, "%u %u ", order, preference));
 348                 T(addstr(t, len, &buf, &buflen));
 349
 350                 /* Flags. */
 351                 T(len = charstr(rdata, edata, &buf, &buflen));
 352                 if (len == 0)
 353                         goto formerr;
 354                 rdata += len;
 355                 T(addstr(" ", 1, &buf, &buflen));
 356
 357                 /* Service. */
 358                 T(len = charstr(rdata, edata, &buf, &buflen));
 359                 if (len == 0)
 360                         goto formerr;
 361                 rdata += len;
 362                 T(addstr(" ", 1, &buf, &buflen));
 363
 364                 /* Regexp. */
 365                 T(len = charstr(rdata, edata, &buf, &buflen));
 366                 if (len < 0)
 367                         return (-1);
 368                 if (len == 0)
 369                         goto formerr;
 370                 rdata += len;
 371                 T(addstr(" ", 1, &buf, &buflen));
 372
 373                 /* Server. */
 374                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 375                 break;
 376             }
 377
 378         case ns_t_srv: {
 379                 u_int priority, weight, port;
 380                 char t[50];
 381
 382                 if (rdlen < NS_INT16SZ*3)
 383                         goto formerr;
 384
 385                 /* Priority, Weight, Port. */
 386                 priority = ns_get16(rdata);  rdata += NS_INT16SZ;
 387                 weight   = ns_get16(rdata);  rdata += NS_INT16SZ;
 388                 port     = ns_get16(rdata);  rdata += NS_INT16SZ;
 389                 len = SPRINTF((t, "%u %u %u ", priority, weight, port));
 390                 T(addstr(t, len, &buf, &buflen));
 391
 392                 /* Server. */
 393                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 394                 break;
 395             }
 396
 397         case ns_t_minfo:
 398         case ns_t_rp:
 399                 /* Name1. */
 400                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 401                 T(addstr(" ", 1, &buf, &buflen));
 402
 403                 /* Name2. */
 404                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 405
 406                 break;
 407
 408         case ns_t_wks: {
 409                 int n, lcnt;
 410
 411                 if (rdlen < NS_INT32SZ + 1)
 412                         goto formerr;
 413
 414                 /* Address. */
 415                 (void) inet_ntop(AF_INET, rdata, buf, buflen);
 416                 addlen(strlen(buf), &buf, &buflen);
 417                 rdata += NS_INADDRSZ;
 418
 419                 /* Protocol. */
 420                 len = SPRINTF((tmp, " %u ( ", *rdata));
 421                 T(addstr(tmp, len, &buf, &buflen));
 422                 rdata += NS_INT8SZ;
 423
 424                 /* Bit map. */
 425                 n = 0;
 426                 lcnt = 0;
 427                 while (rdata < edata) {
 428                         u_int c = *rdata++;
 429                         do {
 430                                 if (c & 0200) {
 431                                         if (lcnt == 0) {
 432                                                 T(addstr("\n\t\t\t\t", 5,
 433                                                          &buf, &buflen));
 434                                                 lcnt = 10;
 435                                                 spaced = 0;
 436                                         }
 437                                         len = SPRINTF((tmp, "%d ", n));
 438                                         T(addstr(tmp, len, &buf, &buflen));
 439                                         lcnt--;
 440                                 }
 441                                 c <<= 1;
 442                         } while (++n & 07);
 443                 }
 444                 T(addstr(")", 1, &buf, &buflen));
 445
 446                 break;
 447             }
 448
 449         case ns_t_key: {
 450 #ifndef _LIBC
 451                 char base64_key[NS_MD5RSA_MAX_BASE64];
 452                 u_int keyflags, protocol, algorithm, key_id;
 453                 const char *leader;
 454                 int n;
 455
 456                 if (rdlen < NS_INT16SZ + NS_INT8SZ + NS_INT8SZ)
 457                         goto formerr;
 458
 459                 /* Key flags, Protocol, Algorithm. */
 460                 key_id = dst_s_dns_key_id(rdata, edata-rdata);
 461                 keyflags = ns_get16(rdata);  rdata += NS_INT16SZ;
 462                 protocol = *rdata++;
 463                 algorithm = *rdata++;
 464                 len = SPRINTF((tmp, "0x%04x %u %u",
 465                                keyflags, protocol, algorithm));
 466                 T(addstr(tmp, len, &buf, &buflen));
 467
 468                 /* Public key data. */
 469                 len = b64_ntop(rdata, edata - rdata,
 470                                base64_key, sizeof base64_key);
 471                 if (len < 0)
 472                         goto formerr;
 473                 if (len > 15) {
 474                         T(addstr(" (", 2, &buf, &buflen));
 475                         leader = "\n\t\t";
 476                         spaced = 0;
 477                 } else
 478                         leader = " ";
 479                 for (n = 0; n < len; n += 48) {
 480                         T(addstr(leader, strlen(leader), &buf, &buflen));
 481                         T(addstr(base64_key + n, MIN(len - n, 48),
 482                                  &buf, &buflen));
 483                 }
 484                 if (len > 15)
 485                         T(addstr(" )", 2, &buf, &buflen));
 486                 n = SPRINTF((tmp, " ; key_tag= %u", key_id));
 487                 T(addstr(tmp, n, &buf, &buflen));
 488 #endif /* !_LIBC */
 489
 490                 break;
 491             }
 492
 493         case ns_t_sig: {
 494 #ifndef _LIBC
 495                 char base64_key[NS_MD5RSA_MAX_BASE64];
 496                 u_int type, algorithm, labels, footprint;
 497                 const char *leader;
 498                 u_long t;
 499                 int n;
 500
 501                 if (rdlen < 22)
 502                         goto formerr;
 503
 504                 /* Type covered, Algorithm, Label count, Original TTL. */
 505                 type = ns_get16(rdata);  rdata += NS_INT16SZ;
 506                 algorithm = *rdata++;
 507                 labels = *rdata++;
 508                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 509                 len = SPRINTF((tmp, "%s %d %d %lu ",
 510                                p_type(type), algorithm, labels, t));
 511                 T(addstr(tmp, len, &buf, &buflen));
 512                 if (labels > (u_int)dn_count_labels(name))
 513                         goto formerr;
 514
 515                 /* Signature expiry. */
 516                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 517                 len = SPRINTF((tmp, "%s ", p_secstodate(t)));
 518                 T(addstr(tmp, len, &buf, &buflen));
 519
 520                 /* Time signed. */
 521                 t = ns_get32(rdata);  rdata += NS_INT32SZ;
 522                 len = SPRINTF((tmp, "%s ", p_secstodate(t)));
 523                 T(addstr(tmp, len, &buf, &buflen));
 524
 525                 /* Signature Footprint. */
 526                 footprint = ns_get16(rdata);  rdata += NS_INT16SZ;
 527                 len = SPRINTF((tmp, "%u ", footprint));
 528                 T(addstr(tmp, len, &buf, &buflen));
 529
 530                 /* Signer's name. */
 531                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 532
 533                 /* Signature. */
 534                 len = b64_ntop(rdata, edata - rdata,
 535                                base64_key, sizeof base64_key);
 536                 if (len > 15) {
 537                         T(addstr(" (", 2, &buf, &buflen));
 538                         leader = "\n\t\t";
 539                         spaced = 0;
 540                 } else
 541                         leader = " ";
 542                 if (len < 0)
 543                         goto formerr;
 544                 for (n = 0; n < len; n += 48) {
 545                         T(addstr(leader, strlen(leader), &buf, &buflen));
 546                         T(addstr(base64_key + n, MIN(len - n, 48),
 547                                  &buf, &buflen));
 548                 }
 549                 if (len > 15)
 550                         T(addstr(" )", 2, &buf, &buflen));
 551 #endif /* !_LIBC */
 552                 break;
 553             }
 554
 555         case ns_t_nxt: {
 556                 int n, c;
 557
 558                 /* Next domain name. */
 559                 T(addname(msg, msglen, &rdata, origin, &buf, &buflen));
 560
 561                 /* Type bit map. */
 562                 n = edata - rdata;
 563                 for (c = 0; c < n*8; c++)
 564                         if (NS_NXT_BIT_ISSET(c, rdata)) {
 565                                 len = SPRINTF((tmp, " %s", p_type(c)));
 566                                 T(addstr(tmp, len, &buf, &buflen));
 567                         }
 568                 break;
 569             }
 570
 571         case ns_t_cert: {
 572                 u_int c_type, key_tag, alg;
 573                 int n, siz;
 574                 char base64_cert[8192], *leader, tmp[40];
 575
 576                 c_type  = ns_get16(rdata); rdata += NS_INT16SZ;
 577                 key_tag = ns_get16(rdata); rdata += NS_INT16SZ;
 578                 alg = (u_int) *rdata++;
 579
 580                 len = SPRINTF((tmp, "%d %d %d ", c_type, key_tag, alg));
 581                 T(addstr(tmp, len, &buf, &buflen));
 582                 siz = (edata-rdata)*4/3 + 4; /* "+4" accounts for trailing \0 */
 583                 if (siz > sizeof(base64_cert) * 3/4) {
 584                         char *str = "record too long to print";
 585                         T(addstr(str, strlen(str), &buf, &buflen));
 586                 }
 587                 else {
 588                         len = b64_ntop(rdata, edata-rdata, base64_cert, siz);
 589
 590                         if (len < 0)
 591                                 goto formerr;
 592                         else if (len > 15) {
 593                                 T(addstr(" (", 2, &buf, &buflen));
 594                                 leader = "\n\t\t";
 595                                 spaced = 0;
 596                         }
 597                         else
 598                                 leader = " ";
 599
 600                         for (n = 0; n < len; n += 48) {
 601                                 T(addstr(leader, strlen(leader),
 602                                          &buf, &buflen));
 603                                 T(addstr(base64_cert + n, MIN(len - n, 48),
 604                                          &buf, &buflen));
 605                         }
 606                         if (len > 15)
 607                                 T(addstr(" )", 2, &buf, &buflen));
 608                 }
 609                 break;
 610             }
 611
 612         case ns_t_tsig: {
 613                 /* BEW - need to complete this */
 614                 int n;
 615
 616                 T(len = addname(msg, msglen, &rdata, origin, &buf, &buflen));
 617                 T(addstr(" ", 1, &buf, &buflen));
 618                 rdata += 8; /* time */
 619                 n = ns_get16(rdata); rdata += INT16SZ;
 620                 rdata += n; /* sig */
 621                 n = ns_get16(rdata); rdata += INT16SZ; /* original id */
 622                 sprintf(buf, "%d", ns_get16(rdata));
 623                 rdata += INT16SZ;
 624                 addlen(strlen(buf), &buf, &buflen);
 625                 break;
 626             }
 627
 628         default:
 629                 comment = "unknown RR type";
 630                 goto hexify;
 631         }
 632         return (buf - obuf);
 633  formerr:
 634         comment = "RR format error";
 635  hexify: {
 636         int n, m;
 637         char *p;
 638
 639         len = SPRINTF((tmp, "\\#(\t\t; %s", comment));
 640         T(addstr(tmp, len, &buf, &buflen));
 641         while (rdata < edata) {
 642                 p = tmp;
 643                 p += SPRINTF((p, "\n\t"));
 644                 spaced = 0;
 645                 n = MIN(16, edata - rdata);
 646                 for (m = 0; m < n; m++)
 647                         p += SPRINTF((p, "%02x ", rdata[m]));
 648                 T(addstr(tmp, p - tmp, &buf, &buflen));
 649                 if (n < 16) {
 650                         T(addstr(")", 1, &buf, &buflen));
 651                         T(addtab(p - tmp + 1, 48, spaced, &buf, &buflen));
 652                 }
 653                 p = tmp;
 654                 p += SPRINTF((p, "; "));
 655                 for (m = 0; m < n; m++)
 656                         *p++ = (isascii(rdata[m]) && isprint(rdata[m]))
 657                                 ? rdata[m]
 658                                 : '.';
 659                 T(addstr(tmp, p - tmp, &buf, &buflen));
 660                 rdata += n;
 661         }
 662         return (buf - obuf);
 663     }
 664 }
 665
 666 /* Private. */
 667
 668 /*
 669  * size_t
 670  * prune_origin(name, origin)
 671  *      Find out if the name is at or under the current origin.
 672  * return:
 673  *      Number of characters in name before start of origin,
 674  *      or length of name if origin does not match.
 675  * notes:
 676  *      This function should share code with samedomain().
 677  */
 678 static size_t
 679 prune_origin(const char *name, const char *origin) {
 680         const char *oname = name;
 681
 682         while (*name != '\0') {
 683                 if (origin != NULL && ns_samename(name, origin) == 1)
 684                         return (name - oname - (name > oname));
 685                 while (*name != '\0') {
 686                         if (*name == '\\') {
 687                                 name++;
 688                                 /* XXX need to handle \nnn form. */
 689                                 if (*name == '\0')
 690                                         break;
 691                         } else if (*name == '.') {
 692                                 name++;
 693                                 break;
 694                         }
 695                         name++;
 696                 }
 697         }
 698         return (name - oname);
 699 }
 700
 701 /*
 702  * int
 703  * charstr(rdata, edata, buf, buflen)
 704  *      Format a <character-string> into the presentation buffer.
 705  * return:
 706  *      Number of rdata octets consumed
 707  *      0 for protocol format error
 708  *      -1 for output buffer error
 709  * side effects:
 710  *      buffer is advanced on success.
 711  */
 712 static int
 713 charstr(const u_char *rdata, const u_char *edata, char **buf, size_t *buflen) {
 714         const u_char *odata = rdata;
 715         size_t save_buflen = *buflen;
 716         char *save_buf = *buf;
 717
 718         if (addstr("\"", 1, buf, buflen) < 0)
 719                 goto enospc;
 720         if (rdata < edata) {
 721                 int n = *rdata;
 722
 723                 if (rdata + 1 + n <= edata) {
 724                         rdata++;
 725                         while (n-- > 0) {
 726                                 if (strchr("\n\"\\", *rdata) != NULL)
 727                                         if (addstr("\\", 1, buf, buflen) < 0)
 728                                                 goto enospc;
 729                                 if (addstr((const char *)rdata, 1,
 730                                            buf, buflen) < 0)
 731                                         goto enospc;
 732                                 rdata++;
 733                         }
 734                 }
 735         }
 736         if (addstr("\"", 1, buf, buflen) < 0)
 737                 goto enospc;
 738         return (rdata - odata);
 739  enospc:
 740         __set_errno (ENOSPC);
 741         *buf = save_buf;
 742         *buflen = save_buflen;
 743         return (-1);
 744 }
 745
 746 static int
 747 addname(const u_char *msg, size_t msglen,
 748         const u_char **pp, const char *origin,
 749         char **buf, size_t *buflen)
 750 {
 751         size_t newlen, save_buflen = *buflen;
 752         char *save_buf = *buf;
 753         int n;
 754
 755         n = dn_expand(msg, msg + msglen, *pp, *buf, *buflen);
 756         if (n < 0)
 757                 goto enospc;    /* Guess. */
 758         newlen = prune_origin(*buf, origin);
 759         if (newlen == 0) {
 760                 /* Use "@" instead of name. */
 761                 if (newlen + 2 > *buflen)
 762                         goto enospc;        /* No room for "@\0". */
 763                 (*buf)[newlen++] = '@';
 764                 (*buf)[newlen] = '\0';
 765         } else {
 766                 if (((origin == NULL || origin[0] == '\0') ||
 767                     (origin[0] != '.' && origin[1] != '\0' &&
 768                     (*buf)[newlen] == '\0')) && (*buf)[newlen - 1] != '.') {
 769                         /* No trailing dot. */
 770                         if (newlen + 2 > *buflen)
 771                                 goto enospc;    /* No room for ".\0". */
 772                         (*buf)[newlen++] = '.';
 773                         (*buf)[newlen] = '\0';
 774                 }
 775         }
 776         *pp += n;
 777         addlen(newlen, buf, buflen);
 778         **buf = '\0';
 779         return (newlen);
 780  enospc:
 781         __set_errno (ENOSPC);
 782         *buf = save_buf;
 783         *buflen = save_buflen;
 784         return (-1);
 785 }
 786
 787 static void
 788 addlen(size_t len, char **buf, size_t *buflen) {
 789         assert(len <= *buflen);
 790         *buf += len;
 791         *buflen -= len;
 792 }
 793
 794 static int
 795 addstr(const char *src, size_t len, char **buf, size_t *buflen) {
 796         if (len >= *buflen) {
 797                 __set_errno (ENOSPC);
 798                 return (-1);
 799         }
 800         memcpy(*buf, src, len);
 801         addlen(len, buf, buflen);
 802         **buf = '\0';
 803         return (0);
 804 }
 805
 806 static int
 807 addtab(size_t len, size_t target, int spaced, char **buf, size_t *buflen) {
 808         size_t save_buflen = *buflen;
 809         char *save_buf = *buf;
 810         int t;
 811
 812         if (spaced || len >= target - 1) {
 813                 T(addstr("  ", 2, buf, buflen));
 814                 spaced = 1;
 815         } else {
 816                 for (t = (target - len - 1) / 8; t >= 0; t--)
 817                         if (addstr("\t", 1, buf, buflen) < 0) {
 818                                 *buflen = save_buflen;
 819                                 *buf = save_buf;
 820                                 return (-1);
 821                         }
 822                 spaced = 0;
 823         }
 824         return (spaced);
 825 }