/src/bind9/lib/dns/rdata.c

Source
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <ctype.h>
#include <inttypes.h>
#include <stdbool.h>

#include <openssl/err.h>
#include <openssl/objects.h>

#include <isc/ascii.h>
#include <isc/base64.h>
#include <isc/hex.h>
#include <isc/lex.h>
#include <isc/mem.h>
#include <isc/parseint.h>
#include <isc/result.h>
#include <isc/string.h>
#include <isc/utf8.h>
#include <isc/util.h>

#include <dns/callbacks.h>
#include <dns/cert.h>
#include <dns/compress.h>
#include <dns/db.h>
#include <dns/dsdigest.h>
#include <dns/enumtype.h>
#include <dns/fixedname.h>
#include <dns/keyflags.h>
#include <dns/keyvalues.h>
#include <dns/message.h>
#include <dns/rcode.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/secalg.h>
#include <dns/secproto.h>
#include <dns/time.h>
#include <dns/ttl.h>

#define RETTOK(x)                                          \
  do {                                               \
    isc_result_t _r = (x);                     \
    if (_r != ISC_R_SUCCESS) {                 \
      isc_lex_ungettoken(lexer, &token); \
      return (_r);                       \
    }                                          \
  } while (0)

#define CHECKTOK(op)                                       \
  do {                                               \
    result = (op);                             \
    if (result != ISC_R_SUCCESS) {             \
      isc_lex_ungettoken(lexer, &token); \
      goto cleanup;                      \
    }                                          \
  } while (0)

#define DNS_AS_STR(t) ((t).value.as_textregion.base)

#define ARGS_FROMTEXT                                           \
  int rdclass, dns_rdatatype_t type, isc_lex_t *lexer,    \
    const dns_name_t *origin, unsigned int options, \
    isc_buffer_t *target, dns_rdatacallbacks_t *callbacks

#define CALL_FROMTEXT rdclass, type, lexer, origin, options, target, callbacks

#define ARGS_TOTEXT \
  dns_rdata_t *rdata, dns_rdata_textctx_t *tctx, isc_buffer_t *target

#define CALL_TOTEXT rdata, tctx, target

#define ARGS_FROMWIRE                                            \
  int rdclass, dns_rdatatype_t type, isc_buffer_t *source, \
    dns_decompress_t dctx, isc_buffer_t *target

#define CALL_FROMWIRE rdclass, type, source, dctx, target

#define ARGS_TOWIRE \
  dns_rdata_t *rdata, dns_compress_t *cctx, isc_buffer_t *target

#define CALL_TOWIRE rdata, cctx, target

#define ARGS_COMPARE const dns_rdata_t *rdata1, const dns_rdata_t *rdata2

#define CALL_COMPARE rdata1, rdata2

#define ARGS_FROMSTRUCT \
  int rdclass, dns_rdatatype_t type, void *source, isc_buffer_t *target

#define CALL_FROMSTRUCT rdclass, type, source, target

#define ARGS_TOSTRUCT const dns_rdata_t *rdata, void *target, isc_mem_t *mctx

#define CALL_TOSTRUCT rdata, target, mctx

#define ARGS_FREESTRUCT void *source

#define CALL_FREESTRUCT source

#define ARGS_ADDLDATA                                \
  dns_rdata_t *rdata, const dns_name_t *owner, \
    dns_additionaldatafunc_t add, void *arg

#define CALL_ADDLDATA rdata, owner, add, arg

#define ARGS_DIGEST dns_rdata_t *rdata, dns_digestfunc_t digest, void *arg

#define CALL_DIGEST rdata, digest, arg

#define ARGS_CHECKOWNER                                   \
  const dns_name_t *name, dns_rdataclass_t rdclass, \
    dns_rdatatype_t type, bool wildcard

#define CALL_CHECKOWNER name, rdclass, type, wildcard

#define ARGS_CHECKNAMES \
  dns_rdata_t *rdata, const dns_name_t *owner, dns_name_t *bad

#define CALL_CHECKNAMES rdata, owner, bad

/*%
 * Context structure for the totext_ functions.
 * Contains formatting options for rdata-to-text
 * conversion.
 */
typedef struct dns_rdata_textctx {
  const dns_name_t *origin;      /*%< Current origin, or NULL. */
  dns_masterstyle_flags_t flags; /*%< DNS_STYLEFLAG_*  */
  unsigned int width;        /*%< Width of rdata column. */
  const char *linebreak;         /*%< Line break string. */
} dns_rdata_textctx_t;

static isc_result_t
txt_totext(isc_region_t *source, bool quote, isc_buffer_t *target);

static isc_result_t
txt_fromtext(isc_textregion_t *source, isc_buffer_t *target);

static isc_result_t
txt_fromwire(isc_buffer_t *source, isc_buffer_t *target);

static isc_result_t
commatxt_fromtext(isc_textregion_t *source, bool comma, isc_buffer_t *target);

static isc_result_t
commatxt_totext(isc_region_t *source, bool quote, bool comma,
    isc_buffer_t *target);

static isc_result_t
multitxt_totext(isc_region_t *source, isc_buffer_t *target);

static isc_result_t
multitxt_fromtext(isc_textregion_t *source, isc_buffer_t *target);

static bool
name_prefix(dns_name_t *name, const dns_name_t *origin, dns_name_t *target);

static unsigned int
name_length(const dns_name_t *name);

static isc_result_t
str_totext(const char *source, isc_buffer_t *target);

static isc_result_t
inet_totext(int af, uint32_t flags, isc_region_t *src, isc_buffer_t *target);

static bool
buffer_empty(isc_buffer_t *source);

static void
buffer_fromregion(isc_buffer_t *buffer, isc_region_t *region);

static isc_result_t
uint32_tobuffer(uint32_t, isc_buffer_t *target);

static isc_result_t
uint16_tobuffer(uint32_t, isc_buffer_t *target);

static isc_result_t
uint8_tobuffer(uint32_t, isc_buffer_t *target);

static isc_result_t
name_tobuffer(const dns_name_t *name, isc_buffer_t *target);

static uint32_t
uint32_fromregion(isc_region_t *region);

static uint16_t
uint16_fromregion(isc_region_t *region);

static uint8_t
uint8_fromregion(isc_region_t *region);

static uint8_t
uint8_consume_fromregion(isc_region_t *region);

static isc_result_t
mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length);

static int
hexvalue(char value);

static int
decvalue(char value);

static void
default_fromtext_callback(dns_rdatacallbacks_t *callbacks, const char *, ...)
  ISC_FORMAT_PRINTF(2, 3);

static void
fromtext_error(void (*callback)(dns_rdatacallbacks_t *, const char *, ...),
         dns_rdatacallbacks_t *callbacks, const char *name,
         unsigned long line, isc_token_t *token, isc_result_t result);

static void
fromtext_warneof(isc_lex_t *lexer, dns_rdatacallbacks_t *callbacks);

static isc_result_t
rdata_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
       isc_buffer_t *target);

static void
warn_badname(const dns_name_t *name, isc_lex_t *lexer,
       dns_rdatacallbacks_t *callbacks);

static void
warn_badmx(isc_token_t *token, isc_lex_t *lexer,
     dns_rdatacallbacks_t *callbacks);

static uint16_t
uint16_consume_fromregion(isc_region_t *region);

static isc_result_t
unknown_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
         isc_buffer_t *target);

static isc_result_t generic_fromtext_key(ARGS_FROMTEXT);

static isc_result_t generic_totext_key(ARGS_TOTEXT);

static isc_result_t generic_fromwire_key(ARGS_FROMWIRE);

static isc_result_t generic_fromstruct_key(ARGS_FROMSTRUCT);

static isc_result_t generic_tostruct_key(ARGS_TOSTRUCT);

static void generic_freestruct_key(ARGS_FREESTRUCT);

static isc_result_t generic_fromtext_txt(ARGS_FROMTEXT);

static isc_result_t generic_totext_txt(ARGS_TOTEXT);

static isc_result_t generic_fromwire_txt(ARGS_FROMWIRE);

static isc_result_t generic_fromstruct_txt(ARGS_FROMSTRUCT);

static isc_result_t generic_tostruct_txt(ARGS_TOSTRUCT);

static void generic_freestruct_txt(ARGS_FREESTRUCT);

static isc_result_t
generic_txt_first(dns_rdata_txt_t *txt);

static isc_result_t
generic_txt_next(dns_rdata_txt_t *txt);

static isc_result_t
generic_txt_current(dns_rdata_txt_t *txt, dns_rdata_txt_string_t *string);

static isc_result_t generic_totext_ds(ARGS_TOTEXT);

static isc_result_t generic_tostruct_ds(ARGS_TOSTRUCT);

static isc_result_t generic_fromtext_ds(ARGS_FROMTEXT);

static isc_result_t generic_fromwire_ds(ARGS_FROMWIRE);

static isc_result_t generic_fromstruct_ds(ARGS_FROMSTRUCT);

static isc_result_t generic_fromtext_tlsa(ARGS_FROMTEXT);

static isc_result_t generic_totext_tlsa(ARGS_TOTEXT);

static isc_result_t generic_fromwire_tlsa(ARGS_FROMWIRE);

static isc_result_t generic_fromstruct_tlsa(ARGS_FROMSTRUCT);

static isc_result_t generic_tostruct_tlsa(ARGS_TOSTRUCT);

static void generic_freestruct_tlsa(ARGS_FREESTRUCT);

static isc_result_t generic_fromtext_in_svcb(ARGS_FROMTEXT);
static isc_result_t generic_totext_in_svcb(ARGS_TOTEXT);
static isc_result_t generic_fromwire_in_svcb(ARGS_FROMWIRE);
static isc_result_t generic_towire_in_svcb(ARGS_TOWIRE);
static isc_result_t generic_fromstruct_in_svcb(ARGS_FROMSTRUCT);
static isc_result_t generic_tostruct_in_svcb(ARGS_TOSTRUCT);
static void generic_freestruct_in_svcb(ARGS_FREESTRUCT);
static isc_result_t generic_additionaldata_in_svcb(ARGS_ADDLDATA);
static bool generic_checknames_in_svcb(ARGS_CHECKNAMES);
static isc_result_t
generic_rdata_in_svcb_first(dns_rdata_in_svcb_t *);
static isc_result_t
generic_rdata_in_svcb_next(dns_rdata_in_svcb_t *);
static void
generic_rdata_in_svcb_current(dns_rdata_in_svcb_t *, isc_region_t *);

/*% INT16 Size */
#define NS_INT16SZ 2
/*% IPv6 Address Size */
#define NS_LOCATORSZ 8

/*
 * Active Directory gc._msdcs.<forest> prefix.
 */
static unsigned char gc_msdcs_data[] = "\002gc\006_msdcs";

static dns_name_t const gc_msdcs = DNS_NAME_INITNONABSOLUTE(gc_msdcs_data);

/*%
 *  convert presentation level address to network order binary form.
 * \return
 *  1 if `src' is a valid [RFC1884 2.2] address, else 0.
 * \note
 *  (1) does not touch `dst' unless it's returning 1.
 */
static int
locator_pton(const char *src, unsigned char *dst) {
  unsigned char tmp[NS_LOCATORSZ];
  unsigned char *tp = tmp, *endp;
  int ch, seen_xdigits;
  unsigned int val, hexval;

  memset(tp, '\0', NS_LOCATORSZ);
  endp = tp + NS_LOCATORSZ;
  seen_xdigits = 0;
  val = 0;
  while ((ch = *src++) != '\0') {
    hexval = isc_hex_char(ch);
    if (hexval != 0) {
      val <<= 4;
      val |= (ch - hexval);
      if (++seen_xdigits > 4) {
        return 0;
      }
      continue;
    }
    if (ch == ':') {
      if (!seen_xdigits) {
        return 0;
      }
      if (tp + NS_INT16SZ > endp) {
        return 0;
      }
      *tp++ = (unsigned char)(val >> 8) & 0xff;
      *tp++ = (unsigned char)val & 0xff;
      seen_xdigits = 0;
      val = 0;
      continue;
    }
    return 0;
  }
  if (seen_xdigits) {
    if (tp + NS_INT16SZ > endp) {
      return 0;
    }
    *tp++ = (unsigned char)(val >> 8) & 0xff;
    *tp++ = (unsigned char)val & 0xff;
  }
  if (tp != endp) {
    return 0;
  }
  memmove(dst, tmp, NS_LOCATORSZ);
  return 1;
}

static void
name_duporclone(const dns_name_t *source, isc_mem_t *mctx, dns_name_t *target) {
  if (mctx != NULL) {
    dns_name_dup(source, mctx, target);
  } else {
    dns_name_clone(source, target);
  }
}

static void *
mem_maybedup(isc_mem_t *mctx, void *source, size_t length) {
  void *copy = NULL;

  REQUIRE(source != NULL);

  if (mctx == NULL) {
    return source;
  }

  copy = isc_mem_allocate(mctx, length);
  memmove(copy, source, length);

  return copy;
}

static isc_result_t
typemap_fromtext(isc_lex_t *lexer, isc_buffer_t *target, bool allow_empty) {
  isc_token_t token;
  unsigned char bm[8 * 1024]; /* 64k bits */
  dns_rdatatype_t covered, max_used;
  int octet;
  unsigned int max_octet, newend, end;
  int window;
  bool first = true;

  max_used = 0;
  bm[0] = 0;
  end = 0;

  do {
    RETERR(isc_lex_getmastertoken(lexer, &token,
                isc_tokentype_string, true));
    if (token.type != isc_tokentype_string) {
      break;
    }
    RETTOK(dns_rdatatype_fromtext(&covered,
                &token.value.as_textregion));
    if (covered > max_used) {
      newend = covered / 8;
      if (newend > end) {
        memset(&bm[end + 1], 0, newend - end);
        end = newend;
      }
      max_used = covered;
    }
    bm[covered / 8] |= (0x80 >> (covered % 8));
    first = false;
  } while (1);
  isc_lex_ungettoken(lexer, &token);
  if (!allow_empty && first) {
    return DNS_R_FORMERR;
  }

  for (window = 0; window < 256; window++) {
    if (max_used < window * 256) {
      break;
    }

    max_octet = max_used - (window * 256);
    if (max_octet >= 256) {
      max_octet = 31;
    } else {
      max_octet /= 8;
    }

    /*
     * Find if we have a type in this window.
     */
    for (octet = max_octet; octet >= 0; octet--) {
      if (bm[window * 32 + octet] != 0) {
        break;
      }
    }
    if (octet < 0) {
      continue;
    }
    RETERR(uint8_tobuffer(window, target));
    RETERR(uint8_tobuffer(octet + 1, target));
    RETERR(mem_tobuffer(target, &bm[window * 32], octet + 1));
  }
  return ISC_R_SUCCESS;
}

static isc_result_t
typemap_totext(isc_region_t *sr, dns_rdata_textctx_t *tctx,
         isc_buffer_t *target) {
  unsigned int i, j, k;
  unsigned int window, len;
  bool first = true;

  for (i = 0; i < sr->length; i += len) {
    if (tctx != NULL &&
        (tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
    {
      RETERR(str_totext(tctx->linebreak, target));
      first = true;
    }
    INSIST(i + 2 <= sr->length);
    window = sr->base[i];
    len = sr->base[i + 1];
    INSIST(len > 0 && len <= 32);
    i += 2;
    INSIST(i + len <= sr->length);
    for (j = 0; j < len; j++) {
      dns_rdatatype_t t;
      if (sr->base[i + j] == 0) {
        continue;
      }
      for (k = 0; k < 8; k++) {
        if ((sr->base[i + j] & (0x80 >> k)) == 0) {
          continue;
        }
        t = window * 256 + j * 8 + k;
        if (!first) {
          RETERR(str_totext(" ", target));
        }
        first = false;
        if (dns_rdatatype_isknown(t)) {
          RETERR(dns_rdatatype_totext(t, target));
        } else {
          char buf[sizeof("TYPE65535")];
          snprintf(buf, sizeof(buf), "TYPE%u", t);
          RETERR(str_totext(buf, target));
        }
      }
    }
  }
  return ISC_R_SUCCESS;
}

static isc_result_t
typemap_test(isc_region_t *sr, bool allow_empty) {
  unsigned int window, lastwindow = 0;
  unsigned int len;
  bool first = true;
  unsigned int i;

  for (i = 0; i < sr->length; i += len) {
    /*
     * Check for overflow.
     */
    if (i + 2 > sr->length) {
      RETERR(DNS_R_FORMERR);
    }
    window = sr->base[i];
    len = sr->base[i + 1];
    i += 2;
    /*
     * Check that bitmap windows are in the correct order.
     */
    if (!first && window <= lastwindow) {
      RETERR(DNS_R_FORMERR);
    }
    /*
     * Check for legal lengths.
     */
    if (len < 1 || len > 32) {
      RETERR(DNS_R_FORMERR);
    }
    /*
     * Check for overflow.
     */
    if (i + len > sr->length) {
      RETERR(DNS_R_FORMERR);
    }
    /*
     * The last octet of the bitmap must be non zero.
     */
    if (sr->base[i + len - 1] == 0) {
      RETERR(DNS_R_FORMERR);
    }
    lastwindow = window;
    first = false;
  }
  if (i != sr->length) {
    return DNS_R_EXTRADATA;
  }
  if (!allow_empty && first) {
    RETERR(DNS_R_FORMERR);
  }
  return ISC_R_SUCCESS;
}

static isc_result_t
check_private(isc_buffer_t *source, dns_secalg_t alg) {
  isc_region_t sr;
  if (alg == DNS_KEYALG_PRIVATEDNS) {
    dns_fixedname_t fixed;

    RETERR(dns_name_fromwire(dns_fixedname_initname(&fixed), source,
           DNS_DECOMPRESS_DEFAULT, NULL));
  } else if (alg == DNS_KEYALG_PRIVATEOID) {
    /*
     * Check that we can extract the OID from the start of the
     * key data. We have a length byte followed by the OID BER
     * encoded.
     */
    const unsigned char *in = NULL;
    ASN1_OBJECT *obj = NULL;

    isc_buffer_activeregion(source, &sr);
    if (sr.length < 1 || (unsigned int)*sr.base + 1 > sr.length) {
      RETERR(DNS_R_FORMERR);
    }
    in = sr.base + 1;
    obj = d2i_ASN1_OBJECT(NULL, &in, *sr.base);
    if (obj == NULL) {
      ERR_clear_error();
      RETERR(DNS_R_FORMERR);
    }
    ASN1_OBJECT_free(obj);
    if ((in - sr.base) != (*sr.base + 1)) {
      RETERR(DNS_R_FORMERR);
    }
  }
  return ISC_R_SUCCESS;
}

/*
 * A relative URI template that has a "dns" variable.
 */
static bool
validate_dohpath(isc_region_t *region) {
  const unsigned char *p;
  const unsigned char *v = NULL;
  const unsigned char *n = NULL;
  unsigned char c;
  bool dns = false;
  bool wasop = false;
  enum {
    path,
    variable,
    percent1,
    percent2,
    variable_percent1,
    variable_percent2,
    prefix,
    explode
  } state = path;

  if (region->length == 0 || *region->base != '/' ||
      !isc_utf8_valid(region->base, region->length))
  {
    return false;
  }

  /*
   * RFC 6570 URI Template check + "dns" variable.
   */
  p = region->base;
  while (p < region->base + region->length) {
    switch (state) {
    case path:
      switch (*p++) {
      case '{': /*}*/
        state = variable;
        wasop = false;
        v = p;
        break;
      case '%':
        state = percent1;
        break;
      default:
        break;
      }
      break;
    case variable:
      c = *p++;
      switch (c) {
      case '+':
      case '#':
      case '.':
      case '/':
      case ';':
      case '?':
      case '&':
        /* Operators. */
        if (p != v + 1 || wasop) {
          return false;
        }
        wasop = true;
        v = p;
        break;
      case '=':
      case '!':
      case '@':
      case '|':
        /* Reserved operators. */
        return false;
      case '*':
      case ':':
      case '}':
      case ',':
        /* Found the end of the variable name. */
        if (p == (v + 1)) {
          return false;
        }
        /* 'p' has been incremented so 4 not 3 */
        if ((p - v) == 4 && memcmp(v, "dns", 3) == 0) {
          dns = true;
        }
        switch (c) {
        case ':':
          state = prefix;
          n = p;
          break;
        case /*{*/ '}':
          state = path;
          break;
        case '*':
          state = explode;
          break;
        case ',':
          wasop = false;
          v = p;
          break;
        }
        break;
      case '%':
        /* Percent encoded variable name. */
        state = variable_percent1;
        break;
      default:
        /* Valid variable name character? */
        if (c != '_' && !isalnum(c)) {
          return false;
        }
        break;
      }
      break;
    case explode:
      switch (*p++) {
      case ',':
        state = variable;
        wasop = false;
        v = p;
        break;
      case /*}*/ '}':
        state = path;
        break;
      default:
        return false;
      }
      break;
    /* Check % encoding */
    case percent1:
    case percent2:
    case variable_percent1:
    case variable_percent2:
      /* bad percent encoding? */
      if (!isxdigit(*p++)) {
        return false;
      }
      if (state == percent1) {
        state = percent2;
      } else if (state == percent2) {
        state = path;
      } else if (state == variable_percent1) {
        state = variable_percent2;
      } else {
        state = variable;
      }
      break;
    case prefix:
      c = *p++;
      if (!isdigit(c)) {
        /* valid number range [1..9999] */
        if ((p == n + 1) || (p - n) > 5 || *n == '0') {
          return false;
        }
        switch (c) {
        case ',':
          state = variable;
          wasop = false;
          break;
        case /*{*/ '}':
          state = path;
          break;
        default:
          return false;
        }
      }
      break;
    }
  }
  return state == path && dns;
}

#include "code.h"

#define META   0x0001
#define RESERVED 0x0002

/***
 *** Initialization
 ***/

void
dns_rdata_init(dns_rdata_t *rdata) {
  REQUIRE(rdata != NULL);

  rdata->data = NULL;
  rdata->length = 0;
  rdata->rdclass = 0;
  rdata->type = dns_rdatatype_none;
  rdata->flags = 0;
  ISC_LINK_INIT(rdata, link);
  /* ISC_LIST_INIT(rdata->list); */
}

void
dns_rdata_reset(dns_rdata_t *rdata) {
  REQUIRE(rdata != NULL);

  REQUIRE(!ISC_LINK_LINKED(rdata, link));
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  rdata->data = NULL;
  rdata->length = 0;
  rdata->rdclass = 0;
  rdata->type = dns_rdatatype_none;
  rdata->flags = 0;
}

/***
 ***
 ***/

void
dns_rdata_clone(const dns_rdata_t *src, dns_rdata_t *target) {
  REQUIRE(src != NULL);
  REQUIRE(target != NULL);

  REQUIRE(DNS_RDATA_INITIALIZED(target));

  REQUIRE(DNS_RDATA_VALIDFLAGS(src));
  REQUIRE(DNS_RDATA_VALIDFLAGS(target));

  target->data = src->data;
  target->length = src->length;
  target->rdclass = src->rdclass;
  target->type = src->type;
  target->flags = src->flags;
}

/***
 *** Comparisons
 ***/

int
dns_rdata_compare(const dns_rdata_t *rdata1, const dns_rdata_t *rdata2) {
  int result = 0;
  bool use_default = false;

  REQUIRE(rdata1 != NULL);
  REQUIRE(rdata2 != NULL);
  REQUIRE(rdata1->length == 0 || rdata1->data != NULL);
  REQUIRE(rdata2->length == 0 || rdata2->data != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata1));
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata2));

  if (rdata1->rdclass != rdata2->rdclass) {
    return rdata1->rdclass < rdata2->rdclass ? -1 : 1;
  }

  if (rdata1->type != rdata2->type) {
    return rdata1->type < rdata2->type ? -1 : 1;
  }

  COMPARESWITCH

  if (use_default) {
    isc_region_t r1;
    isc_region_t r2;

    dns_rdata_toregion(rdata1, &r1);
    dns_rdata_toregion(rdata2, &r2);
    result = isc_region_compare(&r1, &r2);
  }
  return result;
}

int
dns_rdata_casecompare(const dns_rdata_t *rdata1, const dns_rdata_t *rdata2) {
  int result = 0;
  bool use_default = false;

  REQUIRE(rdata1 != NULL);
  REQUIRE(rdata2 != NULL);
  REQUIRE(rdata1->length == 0 || rdata1->data != NULL);
  REQUIRE(rdata2->length == 0 || rdata2->data != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata1));
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata2));

  if (rdata1->rdclass != rdata2->rdclass) {
    return rdata1->rdclass < rdata2->rdclass ? -1 : 1;
  }

  if (rdata1->type != rdata2->type) {
    return rdata1->type < rdata2->type ? -1 : 1;
  }

  CASECOMPARESWITCH

  if (use_default) {
    isc_region_t r1;
    isc_region_t r2;

    dns_rdata_toregion(rdata1, &r1);
    dns_rdata_toregion(rdata2, &r2);
    result = isc_region_compare(&r1, &r2);
  }
  return result;
}

/***
 *** Conversions
 ***/

void
dns_rdata_fromregion(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
         dns_rdatatype_t type, isc_region_t *r) {
  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_INITIALIZED(rdata));
  REQUIRE(r != NULL);

  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  rdata->data = r->base;
  rdata->length = r->length;
  rdata->rdclass = rdclass;
  rdata->type = type;
  rdata->flags = 0;
}

void
dns_rdata_toregion(const dns_rdata_t *rdata, isc_region_t *r) {
  REQUIRE(rdata != NULL);
  REQUIRE(r != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  r->base = rdata->data;
  r->length = rdata->length;
}

isc_result_t
dns_rdata_fromwire(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
       dns_rdatatype_t type, isc_buffer_t *source,
       dns_decompress_t dctx, isc_buffer_t *target) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  isc_region_t region;
  isc_buffer_t ss;
  isc_buffer_t st;
  bool use_default = false;
  uint32_t activelength;
  unsigned int length;

  if (rdata != NULL) {
    REQUIRE(DNS_RDATA_INITIALIZED(rdata));
    REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
  }
  REQUIRE(source != NULL);
  REQUIRE(target != NULL);

  if (type == dns_rdatatype_none) {
    return DNS_R_FORMERR;
  }

  ss = *source;
  st = *target;

  activelength = isc_buffer_activelength(source);
  INSIST(activelength < 65536);

  FROMWIRESWITCH

  if (use_default) {
    if (activelength > isc_buffer_availablelength(target)) {
      result = ISC_R_NOSPACE;
    } else {
      isc_buffer_putmem(target, isc_buffer_current(source),
            activelength);
      isc_buffer_forward(source, activelength);
      result = ISC_R_SUCCESS;
    }
  }

  /*
   * Reject any rdata that expands out to more than DNS_RDATA_MAXLENGTH
   * as we cannot transmit it.
   */
  length = isc_buffer_usedlength(target) - isc_buffer_usedlength(&st);
  if (result == ISC_R_SUCCESS && length > DNS_RDATA_MAXLENGTH) {
    result = DNS_R_FORMERR;
  }

  /*
   * We should have consumed all of our buffer.
   */
  if (result == ISC_R_SUCCESS && !buffer_empty(source)) {
    result = DNS_R_EXTRADATA;
  }

  if (rdata != NULL && result == ISC_R_SUCCESS) {
    region.base = isc_buffer_used(&st);
    region.length = length;
    dns_rdata_fromregion(rdata, rdclass, type, &region);
  }

  if (result != ISC_R_SUCCESS) {
    *source = ss;
    *target = st;
  }
  return result;
}

isc_result_t
dns_rdata_towire(dns_rdata_t *rdata, dns_compress_t *cctx,
     isc_buffer_t *target) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  bool use_default = false;
  isc_region_t tr;
  isc_buffer_t st;

  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  /*
   * Some DynDNS meta-RRs have empty rdata.
   */
  if ((rdata->flags & DNS_RDATA_UPDATE) != 0) {
    INSIST(rdata->length == 0);
    return ISC_R_SUCCESS;
  }

  st = *target;

  TOWIRESWITCH

  if (use_default) {
    isc_buffer_availableregion(target, &tr);
    if (tr.length < rdata->length) {
      return ISC_R_NOSPACE;
    }
    memmove(tr.base, rdata->data, rdata->length);
    isc_buffer_add(target, rdata->length);
    return ISC_R_SUCCESS;
  }
  if (result != ISC_R_SUCCESS) {
    *target = st;
    dns_compress_rollback(cctx, target->used);
  }
  return result;
}

/*
 * If the binary data in 'src' is valid uncompressed wire format
 * rdata of class 'rdclass' and type 'type', return ISC_R_SUCCESS
 * and copy the validated rdata to 'dest'.  Otherwise return an error.
 */
static isc_result_t
rdata_validate(isc_buffer_t *src, isc_buffer_t *dest, dns_rdataclass_t rdclass,
         dns_rdatatype_t type) {
  isc_result_t result;

  isc_buffer_setactive(src, isc_buffer_usedlength(src));
  result = dns_rdata_fromwire(NULL, rdclass, type, src,
            DNS_DECOMPRESS_NEVER, dest);

  return result;
}

static isc_result_t
unknown_fromtext(dns_rdataclass_t rdclass, dns_rdatatype_t type,
     isc_lex_t *lexer, isc_mem_t *mctx, isc_buffer_t *target) {
  isc_result_t result;
  isc_buffer_t *buf = NULL;
  isc_token_t token;

  if (type == dns_rdatatype_none || dns_rdatatype_ismeta(type)) {
    return DNS_R_METATYPE;
  }

  RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_number,
              false));
  if (token.value.as_ulong > 65535U) {
    return ISC_R_RANGE;
  }
  isc_buffer_allocate(mctx, &buf, token.value.as_ulong);

  if (token.value.as_ulong != 0U) {
    CHECK(isc_hex_tobuffer(lexer, buf,
               (unsigned int)token.value.as_ulong));
    if (isc_buffer_usedlength(buf) != token.value.as_ulong) {
      CLEANUP(ISC_R_UNEXPECTEDEND);
    }
  }

  if (dns_rdatatype_isknown(type)) {
    result = rdata_validate(buf, target, rdclass, type);
  } else {
    isc_region_t r;
    isc_buffer_usedregion(buf, &r);
    result = isc_buffer_copyregion(target, &r);
  }
  CHECK(result);

  isc_buffer_free(&buf);
  return ISC_R_SUCCESS;

cleanup:
  isc_buffer_free(&buf);
  return result;
}

isc_result_t
dns_rdata_fromtext(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
       dns_rdatatype_t type, isc_lex_t *lexer,
       const dns_name_t *origin, unsigned int options,
       isc_mem_t *mctx, isc_buffer_t *target,
       dns_rdatacallbacks_t *callbacks) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  isc_region_t region;
  isc_buffer_t st;
  isc_token_t token;
  unsigned int lexoptions = ISC_LEXOPT_EOL | ISC_LEXOPT_EOF |
          ISC_LEXOPT_DNSMULTILINE | ISC_LEXOPT_ESCAPE;
  char *name;
  unsigned long line;
  void (*callback)(dns_rdatacallbacks_t *, const char *, ...);
  isc_result_t tresult;
  unsigned int length;
  bool unknown;

  REQUIRE(origin == NULL || dns_name_isabsolute(origin));
  if (rdata != NULL) {
    REQUIRE(DNS_RDATA_INITIALIZED(rdata));
    REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
  }
  if (callbacks != NULL) {
    REQUIRE(callbacks->warn != NULL);
    REQUIRE(callbacks->error != NULL);
  }

  st = *target;

  if (callbacks != NULL) {
    callback = callbacks->error;
  } else {
    callback = default_fromtext_callback;
  }

  result = isc_lex_getmastertoken(lexer, &token, isc_tokentype_qstring,
          true);
  if (result != ISC_R_SUCCESS) {
    name = isc_lex_getsourcename(lexer);
    line = isc_lex_getsourceline(lexer);
    fromtext_error(callback, callbacks, name, line, NULL, result);
    return result;
  }

  unknown = false;
  if (token.type == isc_tokentype_string &&
      strcmp(DNS_AS_STR(token), "\\#") == 0)
  {
    /*
     * If this is a TXT record '\#' could be a escaped '#'.
     * Look to see if the next token is a number and if so
     * treat it as a unknown record format.
     */
    if (type == dns_rdatatype_txt) {
      result = isc_lex_getmastertoken(
        lexer, &token, isc_tokentype_number, false);
      if (result == ISC_R_SUCCESS) {
        isc_lex_ungettoken(lexer, &token);
      }
    }

    if (result == ISC_R_SUCCESS) {
      unknown = true;
      result = unknown_fromtext(rdclass, type, lexer, mctx,
              target);
    } else {
      options |= DNS_RDATA_UNKNOWNESCAPE;
    }
  } else {
    isc_lex_ungettoken(lexer, &token);
  }

  if (!unknown) {
    FROMTEXTSWITCH

    /*
     * Consume to end of line / file.
     * If not at end of line initially set error code.
     * Call callback via fromtext_error once if there was an error.
     */
  }
  do {
    name = isc_lex_getsourcename(lexer);
    line = isc_lex_getsourceline(lexer);
    tresult = isc_lex_gettoken(lexer, lexoptions, &token);
    if (tresult != ISC_R_SUCCESS) {
      if (result == ISC_R_SUCCESS) {
        result = tresult;
      }
      if (callback != NULL) {
        fromtext_error(callback, callbacks, name, line,
                 NULL, result);
      }
      break;
    } else if (token.type != isc_tokentype_eol &&
         token.type != isc_tokentype_eof)
    {
      if (result == ISC_R_SUCCESS) {
        result = DNS_R_EXTRATOKEN;
      }
      if (callback != NULL) {
        fromtext_error(callback, callbacks, name, line,
                 &token, result);
        callback = NULL;
      }
    } else if (result != ISC_R_SUCCESS && callback != NULL) {
      fromtext_error(callback, callbacks, name, line, &token,
               result);
      break;
    } else {
      if (token.type == isc_tokentype_eof) {
        fromtext_warneof(lexer, callbacks);
      }
      break;
    }
  } while (1);

  length = isc_buffer_usedlength(target) - isc_buffer_usedlength(&st);
  if (result == ISC_R_SUCCESS && length > DNS_RDATA_MAXLENGTH) {
    result = ISC_R_NOSPACE;
  }

  if (rdata != NULL && result == ISC_R_SUCCESS) {
    region.base = isc_buffer_used(&st);
    region.length = length;
    dns_rdata_fromregion(rdata, rdclass, type, &region);
  }
  if (result != ISC_R_SUCCESS) {
    *target = st;
  }
  return result;
}

static isc_result_t
unknown_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
         isc_buffer_t *target) {
  isc_result_t result = ISC_R_SUCCESS;
  char buf[sizeof("65535")];
  isc_region_t sr;

  strlcpy(buf, "\\# ", sizeof(buf));
  RETERR(str_totext(buf, target));

  dns_rdata_toregion(rdata, &sr);
  INSIST(sr.length < 65536);
  snprintf(buf, sizeof(buf), "%u", sr.length);
  RETERR(str_totext(buf, target));

  if (sr.length != 0U) {
    if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0) {
      RETERR(str_totext(" ( ", target));
    } else {
      RETERR(str_totext(" ", target));
    }

    if (tctx->width == 0) { /* No splitting */
      result = isc_hex_totext(&sr, 0, "", target);
    } else {
      result = isc_hex_totext(&sr, tctx->width - 2,
            tctx->linebreak, target);
    }
    if (result == ISC_R_SUCCESS &&
        (tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
    {
      result = str_totext(" )", target);
    }
  }
  return result;
}

static isc_result_t
rdata_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
       isc_buffer_t *target) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  bool use_default = false;
  unsigned int cur;

  REQUIRE(rdata != NULL);
  REQUIRE(tctx->origin == NULL || dns_name_isabsolute(tctx->origin));

  /*
   * Some DynDNS meta-RRs have empty rdata.
   */
  if ((rdata->flags & DNS_RDATA_UPDATE) != 0) {
    INSIST(rdata->length == 0);
    return ISC_R_SUCCESS;
  }

  if ((tctx->flags & DNS_STYLEFLAG_UNKNOWNFORMAT) != 0) {
    return unknown_totext(rdata, tctx, target);
  }

  cur = isc_buffer_usedlength(target);

  TOTEXTSWITCH

  if (use_default || (result == ISC_R_NOTIMPLEMENTED)) {
    unsigned int u = isc_buffer_usedlength(target);

    INSIST(u >= cur);
    isc_buffer_subtract(target, u - cur);
    result = unknown_totext(rdata, tctx, target);
  }

  return result;
}

isc_result_t
dns_rdata_totext(dns_rdata_t *rdata, const dns_name_t *origin,
     isc_buffer_t *target) {
  dns_rdata_textctx_t tctx;

  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  /*
   * Set up formatting options for single-line output.
   */
  tctx.origin = origin;
  tctx.flags = 0;
  tctx.width = 60;
  tctx.linebreak = " ";
  return rdata_totext(rdata, &tctx, target);
}

isc_result_t
dns_rdata_tofmttext(dns_rdata_t *rdata, const dns_name_t *origin,
        dns_masterstyle_flags_t flags, unsigned int width,
        unsigned int split_width, const char *linebreak,
        isc_buffer_t *target) {
  dns_rdata_textctx_t tctx;

  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  /*
   * Set up formatting options for formatted output.
   */
  tctx.origin = origin;
  tctx.flags = flags;
  if (split_width == 0xffffffff) {
    tctx.width = width;
  } else {
    tctx.width = split_width;
  }

  if ((flags & DNS_STYLEFLAG_MULTILINE) != 0) {
    tctx.linebreak = linebreak;
  } else {
    if (split_width == 0xffffffff) {
      tctx.width = 60; /* Used for hex word length only. */
    }
    tctx.linebreak = " ";
  }
  return rdata_totext(rdata, &tctx, target);
}

isc_result_t
dns_rdata_fromstruct(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
         dns_rdatatype_t type, void *source, isc_buffer_t *target) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  isc_buffer_t st;
  isc_region_t region;
  bool use_default = false;
  unsigned int length;

  REQUIRE(source != NULL);
  if (rdata != NULL) {
    REQUIRE(DNS_RDATA_INITIALIZED(rdata));
    REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
  }

  st = *target;

  FROMSTRUCTSWITCH

  if (use_default) {
    (void)NULL;
  }

  length = isc_buffer_usedlength(target) - isc_buffer_usedlength(&st);
  if (result == ISC_R_SUCCESS && length > DNS_RDATA_MAXLENGTH) {
    result = ISC_R_NOSPACE;
  }

  if (rdata != NULL && result == ISC_R_SUCCESS) {
    region.base = isc_buffer_used(&st);
    region.length = length;
    dns_rdata_fromregion(rdata, rdclass, type, &region);
  }
  if (result != ISC_R_SUCCESS) {
    *target = st;
  }
  return result;
}

isc_result_t
dns_rdata_tostruct(const dns_rdata_t *rdata, void *target, isc_mem_t *mctx) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  bool use_default = false;

  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
  REQUIRE((rdata->flags & DNS_RDATA_UPDATE) == 0);

  TOSTRUCTSWITCH

  if (use_default) {
    (void)NULL;
  }

  return result;
}

void
dns_rdata_freestruct(void *source) {
  dns_rdatacommon_t *common = source;
  REQUIRE(common != NULL);

  FREESTRUCTSWITCH
}

isc_result_t
dns_rdata_additionaldata(dns_rdata_t *rdata, const dns_name_t *owner,
       dns_additionaldatafunc_t add, void *arg) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  bool use_default = false;

  /*
   * Call 'add' for each name and type from 'rdata' which is subject to
   * additional section processing.
   */

  REQUIRE(rdata != NULL);
  REQUIRE(add != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  ADDITIONALDATASWITCH

  /* No additional processing for unknown types */
  if (use_default) {
    result = ISC_R_SUCCESS;
  }

  return result;
}

isc_result_t
dns_rdata_digest(dns_rdata_t *rdata, dns_digestfunc_t digest, void *arg) {
  isc_result_t result = ISC_R_NOTIMPLEMENTED;
  bool use_default = false;
  isc_region_t r;

  /*
   * Send 'rdata' in DNSSEC canonical form to 'digest'.
   */

  REQUIRE(rdata != NULL);
  REQUIRE(digest != NULL);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  DIGESTSWITCH

  if (use_default) {
    dns_rdata_toregion(rdata, &r);
    result = (digest)(arg, &r);
  }

  return result;
}

bool
dns_rdata_checkowner(const dns_name_t *name, dns_rdataclass_t rdclass,
         dns_rdatatype_t type, bool wildcard) {
  bool result;

  CHECKOWNERSWITCH
  return result;
}

bool
dns_rdata_checknames(dns_rdata_t *rdata, const dns_name_t *owner,
         dns_name_t *bad) {
  bool result;

  CHECKNAMESSWITCH
  return result;
}

unsigned int
dns_rdatatype_attributes(dns_rdatatype_t type) {
  RDATATYPE_ATTRIBUTE_SW
  if (type >= (dns_rdatatype_t)128 && type <= (dns_rdatatype_t)255) {
    return DNS_RDATATYPEATTR_UNKNOWN | DNS_RDATATYPEATTR_META;
  }
  return DNS_RDATATYPEATTR_UNKNOWN;
}

isc_result_t
dns_rdatatype_fromtext(dns_rdatatype_t *typep, isc_textregion_t *source) {
  unsigned int hash;
  unsigned int n;
  unsigned char a, b;

  n = source->length;

  if (n == 0) {
    return DNS_R_UNKNOWN;
  }

  a = isc_ascii_tolower(source->base[0]);
  b = isc_ascii_tolower(source->base[n - 1]);

  hash = ((a + n) * b) % 256;

  /*
   * This switch block is inlined via \#define, and will use "return"
   * to return a result to the caller if it is a valid (known)
   * rdatatype name.
   */
  RDATATYPE_FROMTEXT_SW(hash, source->base, n, typep);

  if (source->length > 4 && source->length < (4 + sizeof("65000")) &&
      strncasecmp("type", source->base, 4) == 0)
  {
    char buf[sizeof("65000")];
    char *endp;
    unsigned int val;

    /*
     * source->base is not required to be NUL terminated.
     * Copy up to remaining bytes and NUL terminate.
     */
    snprintf(buf, sizeof(buf), "%.*s", (int)(source->length - 4),
       source->base + 4);
    val = strtoul(buf, &endp, 10);
    if (*endp == '\0' && val <= 0xffff) {
      *typep = (dns_rdatatype_t)val;
      return ISC_R_SUCCESS;
    }
  }

  return DNS_R_UNKNOWN;
}

isc_result_t
dns_rdatatype_totext(dns_rdatatype_t type, isc_buffer_t *target) {
  RDATATYPE_TOTEXT_SW

  return dns_rdatatype_tounknowntext(type, target);
}

isc_result_t
dns_rdatatype_tounknowntext(dns_rdatatype_t type, isc_buffer_t *target) {
  char buf[sizeof("TYPE65535")];

  snprintf(buf, sizeof(buf), "TYPE%u", type);
  return str_totext(buf, target);
}

void
dns_rdatatype_format(dns_rdatatype_t rdtype, char *array, unsigned int size) {
  isc_result_t result;
  isc_buffer_t buf;

  if (size == 0U) {
    return;
  }

  isc_buffer_init(&buf, array, size);
  result = dns_rdatatype_totext(rdtype, &buf);
  /*
   * Null terminate.
   */
  if (result == ISC_R_SUCCESS) {
    if (isc_buffer_availablelength(&buf) >= 1) {
      isc_buffer_putuint8(&buf, 0);
    } else {
      result = ISC_R_NOSPACE;
    }
  }
  if (result != ISC_R_SUCCESS) {
    strlcpy(array, "<unknown>", size);
  }
}

/*
 * Private function.
 */

static unsigned int
name_length(const dns_name_t *name) {
  return name->length;
}

static isc_result_t
commatxt_totext(isc_region_t *source, bool quote, bool comma,
    isc_buffer_t *target) {
  unsigned int tl;
  unsigned int n;
  unsigned char *sp;
  char *tp;
  isc_region_t region;

  isc_buffer_availableregion(target, &region);
  sp = source->base;
  tp = (char *)region.base;
  tl = region.length;

  n = *sp++;

  REQUIRE(n + 1 <= source->length);
  if (n == 0U) {
    REQUIRE(quote);
  }

  if (quote) {
    if (tl < 1) {
      return ISC_R_NOSPACE;
    }
    *tp++ = '"';
    tl--;
  }
  while (n--) {
    /*
     * \DDD space (0x20) if not quoting.
     */
    if (*sp < (quote ? ' ' : '!') || *sp >= 0x7f) {
      if (tl < 4) {
        return ISC_R_NOSPACE;
      }
      *tp++ = '\\';
      *tp++ = '0' + ((*sp / 100) % 10);
      *tp++ = '0' + ((*sp / 10) % 10);
      *tp++ = '0' + (*sp % 10);
      sp++;
      tl -= 4;
      continue;
    }
    /*
     * Escape double quote and backslash.  If we are not
     * enclosing the string in double quotes, also escape
     * at sign (@) and semicolon (;) unless comma is set.
     * If comma is set, then only escape commas (,).
     */
    if (*sp == '"' || *sp == '\\' || (comma && *sp == ',') ||
        (!comma && !quote && (*sp == '@' || *sp == ';')))
    {
      if (tl < 2) {
        return ISC_R_NOSPACE;
      }
      *tp++ = '\\';
      tl--;
      /*
       * Perform comma escape processing.
       * ',' => '\\,'
       * '\' => '\\\\'
       */
      if (comma && (*sp == ',' || *sp == '\\')) {
        if (tl < ((*sp == '\\') ? 3 : 2)) {
          return ISC_R_NOSPACE;
        }
        *tp++ = '\\';
        tl--;
        if (*sp == '\\') {
          *tp++ = '\\';
          tl--;
        }
      }
    }
    if (tl < 1) {
      return ISC_R_NOSPACE;
    }
    *tp++ = *sp++;
    tl--;
  }
  if (quote) {
    if (tl < 1) {
      return ISC_R_NOSPACE;
    }
    *tp++ = '"';
    tl--;
    POST(tl);
  }
  isc_buffer_add(target, (unsigned int)(tp - (char *)region.base));
  isc_region_consume(source, *source->base + 1);
  return ISC_R_SUCCESS;
}

static isc_result_t
txt_totext(isc_region_t *source, bool quote, isc_buffer_t *target) {
  return commatxt_totext(source, quote, false, target);
}

static isc_result_t
commatxt_fromtext(isc_textregion_t *source, bool comma, isc_buffer_t *target) {
  isc_region_t tregion;
  bool escape = false, comma_escape = false, seen_comma = false;
  unsigned int n, nrem;
  char *s;
  unsigned char *t;
  int d;
  int c;

  isc_buffer_availableregion(target, &tregion);
  s = source->base;
  n = source->length;
  t = tregion.base;
  nrem = tregion.length;
  if (nrem < 1) {
    return ISC_R_NOSPACE;
  }
  /*
   * Length byte.
   */
  nrem--;
  t++;
  /*
   * Maximum text string length.
   */
  if (nrem > 255) {
    nrem = 255;
  }
  while (n-- != 0) {
    c = (*s++) & 0xff;
    if (escape && (d = decvalue((char)c)) != -1) {
      c = d;
      if (n == 0) {
        return DNS_R_SYNTAX;
      }
      n--;
      if ((d = decvalue(*s++)) != -1) {
        c = c * 10 + d;
      } else {
        return DNS_R_SYNTAX;
      }
      if (n == 0) {
        return DNS_R_SYNTAX;
      }
      n--;
      if ((d = decvalue(*s++)) != -1) {
        c = c * 10 + d;
      } else {
        return DNS_R_SYNTAX;
      }
      if (c > 255) {
        return DNS_R_SYNTAX;
      }
    } else if (!escape && c == '\\') {
      escape = true;
      continue;
    }
    escape = false;
    /*
     * Level 1 escape processing complete.
     * If comma is set perform comma escape processing.
     *
     * Level 1  Level 2   ALPN's
     * h1\,h2   =>  h1,h2   =>  h1 and h2
     * h1\\,h2  =>  h1\,h2  =>  h1,h2
     * h1\\h2   =>  h1\h2   =>  h1h2
     * h1\\\\h2 =>  h1\\h2  =>  h1\h2
     */
    if (comma && !comma_escape && c == ',') {
      seen_comma = true;
      break;
    }
    if (comma && !comma_escape && c == '\\') {
      comma_escape = true;
      continue;
    }
    comma_escape = false;
    if (nrem == 0) {
      return (tregion.length <= 256U) ? ISC_R_NOSPACE
              : DNS_R_SYNTAX;
    }
    *t++ = c;
    nrem--;
  }

  /*
   * Incomplete escape processing?
   */
  if (escape || (comma && comma_escape)) {
    return DNS_R_SYNTAX;
  }

  if (comma) {
    /*
     * Disallow empty ALPN at start (",h1" or "\,h1") or
     * in the middle ("h1,,h2" or "h1\,\,h2").
     */
    if ((t - tregion.base - 1) == 0) {
      return DNS_R_SYNTAX;
    }

    /*
     * Consume this ALPN and possible ending comma.
     */
    isc_textregion_consume(source, s - source->base);

    /*
     * Disallow empty ALPN at end ("h1," or "h1\,").
     */
    if (seen_comma && source->length == 0) {
      return DNS_R_SYNTAX;
    }
  }

  *tregion.base = (unsigned char)(t - tregion.base - 1);
  isc_buffer_add(target, *tregion.base + 1);
  return ISC_R_SUCCESS;
}

static isc_result_t
txt_fromtext(isc_textregion_t *source, isc_buffer_t *target) {
  return commatxt_fromtext(source, false, target);
}

static isc_result_t
txt_fromwire(isc_buffer_t *source, isc_buffer_t *target) {
  unsigned int n;
  isc_region_t sregion;
  isc_region_t tregion;

  isc_buffer_activeregion(source, &sregion);
  if (sregion.length == 0) {
    return ISC_R_UNEXPECTEDEND;
  }
  n = *sregion.base + 1;
  if (n > sregion.length) {
    return ISC_R_UNEXPECTEDEND;
  }

  isc_buffer_availableregion(target, &tregion);
  if (n > tregion.length) {
    return ISC_R_NOSPACE;
  }

  if (tregion.base != sregion.base) {
    memmove(tregion.base, sregion.base, n);
  }
  isc_buffer_forward(source, n);
  isc_buffer_add(target, n);
  return ISC_R_SUCCESS;
}

/*
 * Conversion of TXT-like rdata fields without length limits.
 */
static isc_result_t
multitxt_totext(isc_region_t *source, isc_buffer_t *target) {
  unsigned int tl;
  unsigned int n0, n;
  unsigned char *sp;
  char *tp;
  isc_region_t region;

  isc_buffer_availableregion(target, &region);
  sp = source->base;
  tp = (char *)region.base;
  tl = region.length;

  if (tl < 1) {
    return ISC_R_NOSPACE;
  }
  *tp++ = '"';
  tl--;
  do {
    n = source->length;
    n0 = source->length - 1;

    while (n--) {
      if (*sp < ' ' || *sp >= 0x7f) {
        if (tl < 4) {
          return ISC_R_NOSPACE;
        }
        *tp++ = '\\';
        *tp++ = '0' + ((*sp / 100) % 10);
        *tp++ = '0' + ((*sp / 10) % 10);
        *tp++ = '0' + (*sp % 10);
        sp++;
        tl -= 4;
        continue;
      }
      /* double quote, backslash */
      if (*sp == '"' || *sp == '\\') {
        if (tl < 2) {
          return ISC_R_NOSPACE;
        }
        *tp++ = '\\';
        tl--;
      }
      if (tl < 1) {
        return ISC_R_NOSPACE;
      }
      *tp++ = *sp++;
      tl--;
    }
    isc_region_consume(source, n0 + 1);
  } while (source->length != 0);
  if (tl < 1) {
    return ISC_R_NOSPACE;
  }
  *tp++ = '"';
  tl--;
  POST(tl);
  isc_buffer_add(target, (unsigned int)(tp - (char *)region.base));
  return ISC_R_SUCCESS;
}

static isc_result_t
multitxt_fromtext(isc_textregion_t *source, isc_buffer_t *target) {
  isc_region_t tregion;
  bool escape;
  unsigned int n, nrem;
  char *s;
  unsigned char *t0, *t;
  int d;
  int c;

  s = source->base;
  n = source->length;
  escape = false;

  do {
    isc_buffer_availableregion(target, &tregion);
    t0 = t = tregion.base;
    nrem = tregion.length;
    if (nrem < 1) {
      return ISC_R_NOSPACE;
    }

    while (n != 0) {
      --n;
      c = (*s++) & 0xff;
      if (escape && (d = decvalue((char)c)) != -1) {
        c = d;
        if (n == 0) {
          return DNS_R_SYNTAX;
        }
        n--;
        if ((d = decvalue(*s++)) != -1) {
          c = c * 10 + d;
        } else {
          return DNS_R_SYNTAX;
        }
        if (n == 0) {
          return DNS_R_SYNTAX;
        }
        n--;
        if ((d = decvalue(*s++)) != -1) {
          c = c * 10 + d;
        } else {
          return DNS_R_SYNTAX;
        }
        if (c > 255) {
          return DNS_R_SYNTAX;
        }
      } else if (!escape && c == '\\') {
        escape = true;
        continue;
      }
      escape = false;
      *t++ = c;
      nrem--;
      if (nrem == 0) {
        break;
      }
    }
    if (escape) {
      return DNS_R_SYNTAX;
    }

    isc_buffer_add(target, (unsigned int)(t - t0));
  } while (n != 0);
  return ISC_R_SUCCESS;
}

static bool
name_prefix(dns_name_t *name, const dns_name_t *origin, dns_name_t *target) {
  int l1, l2;

  if (origin == NULL) {
    goto return_false;
  }

  if (dns_name_compare(origin, dns_rootname) == 0) {
    goto return_false;
  }

  if (!dns_name_issubdomain(name, origin)) {
    goto return_false;
  }

  l1 = dns_name_countlabels(name);
  l2 = dns_name_countlabels(origin);

  if (l1 == l2) {
    goto return_false;
  }

  /* Master files should be case preserving. */
  dns_name_getlabelsequence(name, l1 - l2, l2, target);
  if (!dns_name_caseequal(origin, target)) {
    goto return_false;
  }

  dns_name_getlabelsequence(name, 0, l1 - l2, target);
  return true;

return_false:
  *target = *name;
  return false;
}

static isc_result_t
str_totext(const char *source, isc_buffer_t *target) {
  unsigned int l;
  isc_region_t region;

  isc_buffer_availableregion(target, &region);
  l = strlen(source);

  if (l > region.length) {
    return ISC_R_NOSPACE;
  }

  memmove(region.base, source, l);
  isc_buffer_add(target, l);
  return ISC_R_SUCCESS;
}

static isc_result_t
inet_totext(int af, uint32_t flags, isc_region_t *src, isc_buffer_t *target) {
  char tmpbuf[64];

  /* Note - inet_ntop doesn't do size checking on its input. */
  if (inet_ntop(af, src->base, tmpbuf, sizeof(tmpbuf)) == NULL) {
    return ISC_R_NOSPACE;
  }
  if (strlen(tmpbuf) > isc_buffer_availablelength(target)) {
    return ISC_R_NOSPACE;
  }
  isc_buffer_putstr(target, tmpbuf);

  /*
   * An IPv6 address ending in "::" breaks YAML
   * parsing, so append 0 in that case.
   */
  if (af == AF_INET6 && (flags & DNS_STYLEFLAG_YAML) != 0) {
    isc_region_t r;
    isc_buffer_usedregion(target, &r);
    if (r.length > 0 && r.base[r.length - 1] == ':') {
      if (isc_buffer_availablelength(target) == 0) {
        return ISC_R_NOSPACE;
      }
      isc_buffer_putmem(target, (const unsigned char *)"0",
            1);
    }
  }

  return ISC_R_SUCCESS;
}

static bool
buffer_empty(isc_buffer_t *source) {
  return (source->current == source->active) ? true : false;
}

static void
buffer_fromregion(isc_buffer_t *buffer, isc_region_t *region) {
  isc_buffer_init(buffer, region->base, region->length);
  isc_buffer_add(buffer, region->length);
  isc_buffer_setactive(buffer, region->length);
}

static isc_result_t
uint32_tobuffer(uint32_t value, isc_buffer_t *target) {
  isc_region_t region;

  isc_buffer_availableregion(target, &region);
  if (region.length < 4) {
    return ISC_R_NOSPACE;
  }
  isc_buffer_putuint32(target, value);
  return ISC_R_SUCCESS;
}

static isc_result_t
uint16_tobuffer(uint32_t value, isc_buffer_t *target) {
  isc_region_t region;

  if (value > 0xffff) {
    return ISC_R_RANGE;
  }
  isc_buffer_availableregion(target, &region);
  if (region.length < 2) {
    return ISC_R_NOSPACE;
  }
  isc_buffer_putuint16(target, (uint16_t)value);
  return ISC_R_SUCCESS;
}

static isc_result_t
uint8_tobuffer(uint32_t value, isc_buffer_t *target) {
  isc_region_t region;

  if (value > 0xff) {
    return ISC_R_RANGE;
  }
  isc_buffer_availableregion(target, &region);
  if (region.length < 1) {
    return ISC_R_NOSPACE;
  }
  isc_buffer_putuint8(target, (uint8_t)value);
  return ISC_R_SUCCESS;
}

static isc_result_t
name_tobuffer(const dns_name_t *name, isc_buffer_t *target) {
  isc_region_t r;
  dns_name_toregion(name, &r);
  return isc_buffer_copyregion(target, &r);
}

static uint32_t
uint32_fromregion(isc_region_t *region) {
  uint32_t value;

  REQUIRE(region->length >= 4);
  value = (uint32_t)region->base[0] << 24;
  value |= (uint32_t)region->base[1] << 16;
  value |= (uint32_t)region->base[2] << 8;
  value |= (uint32_t)region->base[3];
  return value;
}

static uint16_t
uint16_consume_fromregion(isc_region_t *region) {
  uint16_t r = uint16_fromregion(region);

  isc_region_consume(region, 2);
  return r;
}

static uint16_t
uint16_fromregion(isc_region_t *region) {
  REQUIRE(region->length >= 2);

  return (region->base[0] << 8) | region->base[1];
}

static uint8_t
uint8_fromregion(isc_region_t *region) {
  REQUIRE(region->length >= 1);

  return region->base[0];
}

static uint8_t
uint8_consume_fromregion(isc_region_t *region) {
  uint8_t r = uint8_fromregion(region);

  isc_region_consume(region, 1);
  return r;
}

static isc_result_t
mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
  isc_region_t tr;

  if (length == 0U) {
    return ISC_R_SUCCESS;
  }

  isc_buffer_availableregion(target, &tr);
  if (length > tr.length) {
    return ISC_R_NOSPACE;
  }
  if (tr.base != base) {
    memmove(tr.base, base, length);
  }
  isc_buffer_add(target, length);
  return ISC_R_SUCCESS;
}

static int
hexvalue(char value) {
  int hexval = isc_hex_char(value);
  if (hexval == 0) {
    return -1;
  } else {
    return value - hexval;
  }
}

static int
decvalue(char value) {
  if (isdigit((unsigned char)value)) {
    return value - '0';
  } else {
    return -1;
  }
}

static void
default_fromtext_callback(dns_rdatacallbacks_t *callbacks, const char *fmt,
        ...) {
  va_list ap;

  UNUSED(callbacks);

  va_start(ap, fmt);
  vfprintf(stderr, fmt, ap);
  va_end(ap);
  fprintf(stderr, "\n");
}

static void
fromtext_warneof(isc_lex_t *lexer, dns_rdatacallbacks_t *callbacks) {
  if (isc_lex_isfile(lexer) && callbacks != NULL) {
    const char *name = isc_lex_getsourcename(lexer);
    if (name == NULL) {
      name = "UNKNOWN";
    }
    (*callbacks->warn)(callbacks,
           "%s:%lu: file does not end with newline",
           name, isc_lex_getsourceline(lexer));
  }
}

static void
warn_badmx(isc_token_t *token, isc_lex_t *lexer,
     dns_rdatacallbacks_t *callbacks) {
  const char *file;
  unsigned long line;

  if (lexer != NULL) {
    file = isc_lex_getsourcename(lexer);
    line = isc_lex_getsourceline(lexer);
    (*callbacks->warn)(callbacks, "%s:%u: warning: '%s': %s", file,
           line, DNS_AS_STR(*token),
           isc_result_totext(DNS_R_MXISADDRESS));
  }
}

static void
warn_badname(const dns_name_t *name, isc_lex_t *lexer,
       dns_rdatacallbacks_t *callbacks) {
  const char *file;
  unsigned long line;
  char namebuf[DNS_NAME_FORMATSIZE];

  if (lexer != NULL) {
    file = isc_lex_getsourcename(lexer);
    line = isc_lex_getsourceline(lexer);
    dns_name_format(name, namebuf, sizeof(namebuf));
    (*callbacks->warn)(callbacks, "%s:%u: warning: %s: %s", file,
           line, namebuf,
           isc_result_totext(DNS_R_BADNAME));
  }
}

static void
fromtext_error(void (*callback)(dns_rdatacallbacks_t *, const char *, ...),
         dns_rdatacallbacks_t *callbacks, const char *name,
         unsigned long line, isc_token_t *token, isc_result_t result) {
  if (name == NULL) {
    name = "UNKNOWN";
  }

  if (token != NULL) {
    switch (token->type) {
    case isc_tokentype_eol:
      (*callback)(callbacks, "%s: %s:%lu: near eol: %s",
            "dns_rdata_fromtext", name, line,
            isc_result_totext(result));
      break;
    case isc_tokentype_eof:
      (*callback)(callbacks, "%s: %s:%lu: near eof: %s",
            "dns_rdata_fromtext", name, line,
            isc_result_totext(result));
      break;
    case isc_tokentype_number:
      (*callback)(callbacks, "%s: %s:%lu: near %lu: %s",
            "dns_rdata_fromtext", name, line,
            token->value.as_ulong,
            isc_result_totext(result));
      break;
    case isc_tokentype_string:
    case isc_tokentype_qstring:
      (*callback)(callbacks, "%s: %s:%lu: near '%s': %s",
            "dns_rdata_fromtext", name, line,
            DNS_AS_STR(*token),
            isc_result_totext(result));
      break;
    default:
      (*callback)(callbacks, "%s: %s:%lu: %s",
            "dns_rdata_fromtext", name, line,
            isc_result_totext(result));
      break;
    }
  } else {
    (*callback)(callbacks, "dns_rdata_fromtext: %s:%lu: %s", name,
          line, isc_result_totext(result));
  }
}

dns_rdatatype_t
dns_rdata_covers(dns_rdata_t *rdata) {
  if (rdata->type == dns_rdatatype_rrsig) {
    return covers_rrsig(rdata);
  }
  return covers_sig(rdata);
}

void
dns_rdata_exists(dns_rdata_t *rdata, dns_rdatatype_t type) {
  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_INITIALIZED(rdata));

  rdata->data = NULL;
  rdata->length = 0;
  rdata->flags = DNS_RDATA_UPDATE;
  rdata->type = type;
  rdata->rdclass = dns_rdataclass_any;
}

void
dns_rdata_notexist(dns_rdata_t *rdata, dns_rdatatype_t type) {
  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_INITIALIZED(rdata));

  rdata->data = NULL;
  rdata->length = 0;
  rdata->flags = DNS_RDATA_UPDATE;
  rdata->type = type;
  rdata->rdclass = dns_rdataclass_none;
}

void
dns_rdata_deleterrset(dns_rdata_t *rdata, dns_rdatatype_t type) {
  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_INITIALIZED(rdata));

  rdata->data = NULL;
  rdata->length = 0;
  rdata->flags = DNS_RDATA_UPDATE;
  rdata->type = type;
  rdata->rdclass = dns_rdataclass_any;
}

void
dns_rdata_makedelete(dns_rdata_t *rdata) {
  REQUIRE(rdata != NULL);

  rdata->rdclass = dns_rdataclass_none;
}

const char *
dns_rdata_updateop(dns_rdata_t *rdata, dns_section_t section) {
  REQUIRE(rdata != NULL);
  REQUIRE(DNS_RDATA_INITIALIZED(rdata));

  switch (section) {
  case DNS_SECTION_PREREQUISITE:
    switch (rdata->rdclass) {
    case dns_rdataclass_none:
      switch (rdata->type) {
      case dns_rdatatype_any:
        return "domain doesn't exist";
      default:
        return "rrset doesn't exist";
      }
    case dns_rdataclass_any:
      switch (rdata->type) {
      case dns_rdatatype_any:
        return "domain exists";
      default:
        return "rrset exists (value independent)";
      }
    default:
      return "rrset exists (value dependent)";
    }
  case DNS_SECTION_UPDATE:
    switch (rdata->rdclass) {
    case dns_rdataclass_none:
      return "delete";
    case dns_rdataclass_any:
      switch (rdata->type) {
      case dns_rdatatype_any:
        return "delete all rrsets";
      default:
        return "delete rrset";
      }
    default:
      return "add";
    }
  default:
    break;
  }
  return "invalid";
}

static bool
svcb_ishttp(const char *s, size_t len) {
  /*
   * HTTP entries from:
   *
   * https://www.iana.org/assignments/tls-extensiontype-values/\
   * tls-extensiontype-values.xhtml#alpn-protocol-ids
   */
  struct {
    size_t len;
    const char *value;
  } http[] = { { 8, "http/0.9" }, { 8, "http/1.0" }, { 8, "http/1.1" },
         { 2, "h2" }, { 3, "h2c" },    { 2, "h3" } };

  for (size_t i = 0; i < ARRAY_SIZE(http); i++) {
    if (len == http[i].len && memcmp(s, http[i].value, len) == 0) {
      return true;
    }
  }
  return false;
}

static bool
svcb_hashttp(isc_textregion_t *alpn) {
  while (alpn->length > 0) {
    char c, *s;
    unsigned char len = *alpn->base;

    isc_textregion_consume(alpn, 1);

    /*
     * This has to detect "http/1.1", "h2" and "h3", etc.
     * in a comma list.
     */
    s = alpn->base;
    while (len-- > 0) {
      c = *alpn->base;
      isc_textregion_consume(alpn, 1);
      if (c == ',') {
        if (svcb_ishttp(s, (alpn->base - s) - 1)) {
          return true;
        }
        s = alpn->base;
      }
    }
    if (svcb_ishttp(s, alpn->base - s)) {
      return true;
    }
  }
  return false;
}

isc_result_t
dns_rdata_checksvcb(const dns_name_t *owner, const dns_rdata_t *rdata) {
  dns_rdata_in_svcb_t svcb;
  isc_result_t result;

  REQUIRE(owner != NULL);
  REQUIRE(rdata != NULL);
  REQUIRE(rdata->type == dns_rdatatype_svcb);
  REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

  result = dns_rdata_tostruct(rdata, &svcb, NULL);
  RUNTIME_CHECK(result == ISC_R_SUCCESS);

  /*
   * Check that Alias Mode records don't have SvcParamKeys.
   */
  if (svcb.priority == 0 && svcb.svclen != 0) {
    return DNS_R_HAVEPARMKEYS;
  }

  if (dns_name_isdnssvcb(owner)) {
    isc_region_t r = { .base = svcb.svc, .length = svcb.svclen };
    isc_textregion_t alpn;
    uint16_t key = 0, len = 0;

    /* Check for ALPN (key1) */
    while (r.length > 0) {
      key = uint16_fromregion(&r);
      isc_region_consume(&r, 2);
      len = uint16_fromregion(&r);
      isc_region_consume(&r, 2);
      if (key >= SVCB_ALPN_KEY) {
        break;
      }
      isc_region_consume(&r, len);
    }
    if (key != SVCB_ALPN_KEY) {
      return DNS_R_NOALPN;
    }
    alpn = (isc_textregion_t){ .base = (char *)r.base,
             .length = len };
    isc_region_consume(&r, len);
    if (svcb_hashttp(&alpn)) {
      /* Check for DOHPATH (key7) */
      while (r.length > 0) {
        key = uint16_fromregion(&r);
        isc_region_consume(&r, 2);
        len = uint16_fromregion(&r);
        isc_region_consume(&r, 2);
        if (key >= SVCB_DOHPATH_KEY) {
          break;
        }
        isc_region_consume(&r, len);
      }
      if (key != SVCB_DOHPATH_KEY) {
        return DNS_R_NODOHPATH;
      }
    }
  }
  return ISC_R_SUCCESS;
}

Coverage Report

Created: 2026-06-07 06:21