diff options
Diffstat (limited to 'lib/dns/name.c')
| -rw-r--r-- | lib/dns/name.c | 2652 |
1 files changed, 2652 insertions, 0 deletions
diff --git a/lib/dns/name.c b/lib/dns/name.c new file mode 100644 index 0000000..8a258a2 --- /dev/null +++ b/lib/dns/name.c @@ -0,0 +1,2652 @@ +/* + * 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 <stdlib.h> + +#include <isc/buffer.h> +#include <isc/hash.h> +#include <isc/mem.h> +#include <isc/once.h> +#include <isc/print.h> +#include <isc/random.h> +#include <isc/result.h> +#include <isc/string.h> +#include <isc/thread.h> +#include <isc/util.h> + +#include <dns/compress.h> +#include <dns/fixedname.h> +#include <dns/name.h> + +#define VALID_NAME(n) ISC_MAGIC_VALID(n, DNS_NAME_MAGIC) + +typedef enum { + ft_init = 0, + ft_start, + ft_ordinary, + ft_initialescape, + ft_escape, + ft_escdecimal, + ft_at +} ft_state; + +typedef enum { fw_start = 0, fw_ordinary, fw_newcurrent } fw_state; + +static char digitvalue[256] = { + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/ + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /*64*/ + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/ + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/ +}; + +static unsigned char maptolower[] = { + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, + 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, + 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, + 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, + 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, + 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, + 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, + 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, + 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, + 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, + 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, + 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, + 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, + 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, + 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, + 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, + 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, + 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, + 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, + 0xfc, 0xfd, 0xfe, 0xff +}; + +#define CONVERTTOASCII(c) +#define CONVERTFROMASCII(c) + +#define INIT_OFFSETS(name, var, default_offsets) \ + if ((name)->offsets != NULL) \ + var = (name)->offsets; \ + else \ + var = (default_offsets); + +#define SETUP_OFFSETS(name, var, default_offsets) \ + if ((name)->offsets != NULL) { \ + var = (name)->offsets; \ + } else { \ + var = (default_offsets); \ + set_offsets(name, var, NULL); \ + } + +/*% + * Note: If additional attributes are added that should not be set for + * empty names, MAKE_EMPTY() must be changed so it clears them. + */ +#define MAKE_EMPTY(name) \ + do { \ + name->ndata = NULL; \ + name->length = 0; \ + name->labels = 0; \ + name->attributes &= ~DNS_NAMEATTR_ABSOLUTE; \ + } while (0); + +/*% + * A name is "bindable" if it can be set to point to a new value, i.e. + * name->ndata and name->length may be changed. + */ +#define BINDABLE(name) \ + ((name->attributes & \ + (DNS_NAMEATTR_READONLY | DNS_NAMEATTR_DYNAMIC)) == 0) + +/*% + * Note that the name data must be a char array, not a string + * literal, to avoid compiler warnings about discarding + * the const attribute of a string. + */ +static unsigned char root_ndata[] = { "" }; +static unsigned char root_offsets[] = { 0 }; + +static dns_name_t root = DNS_NAME_INITABSOLUTE(root_ndata, root_offsets); +const dns_name_t *dns_rootname = &root; + +static unsigned char wild_ndata[] = { "\001*" }; +static unsigned char wild_offsets[] = { 0 }; + +static dns_name_t const wild = DNS_NAME_INITNONABSOLUTE(wild_ndata, + wild_offsets); + +const dns_name_t *dns_wildcardname = &wild; + +/* + * dns_name_t to text post-conversion procedure. + */ +static thread_local dns_name_totextfilter_t *totext_filter_proc = NULL; + +static void +set_offsets(const dns_name_t *name, unsigned char *offsets, + dns_name_t *set_name); + +void +dns_name_init(dns_name_t *name, unsigned char *offsets) { + /* + * Initialize 'name'. + */ + DNS_NAME_INIT(name, offsets); +} + +void +dns_name_reset(dns_name_t *name) { + REQUIRE(VALID_NAME(name)); + REQUIRE(BINDABLE(name)); + + DNS_NAME_RESET(name); +} + +void +dns_name_invalidate(dns_name_t *name) { + /* + * Make 'name' invalid. + */ + + REQUIRE(VALID_NAME(name)); + + name->magic = 0; + name->ndata = NULL; + name->length = 0; + name->labels = 0; + name->attributes = 0; + name->offsets = NULL; + name->buffer = NULL; + ISC_LINK_INIT(name, link); +} + +bool +dns_name_isvalid(const dns_name_t *name) { + unsigned char *ndata, *offsets; + unsigned int offset, count, length, nlabels; + + if (!VALID_NAME(name)) { + return (false); + } + + if (name->length > 255U || name->labels > 127U) { + return (false); + } + + ndata = name->ndata; + length = name->length; + offsets = name->offsets; + offset = 0; + nlabels = 0; + + while (offset != length) { + count = *ndata; + if (count > 63U) { + return (false); + } + if (offsets != NULL && offsets[nlabels] != offset) { + return (false); + } + + nlabels++; + offset += count + 1; + ndata += count + 1; + if (offset > length) { + return (false); + } + + if (count == 0) { + break; + } + } + + if (nlabels != name->labels || offset != name->length) { + return (false); + } + + return (true); +} + +void +dns_name_setbuffer(dns_name_t *name, isc_buffer_t *buffer) { + /* + * Dedicate a buffer for use with 'name'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE((buffer != NULL && name->buffer == NULL) || (buffer == NULL)); + + name->buffer = buffer; +} + +bool +dns_name_hasbuffer(const dns_name_t *name) { + /* + * Does 'name' have a dedicated buffer? + */ + + REQUIRE(VALID_NAME(name)); + + if (name->buffer != NULL) { + return (true); + } + + return (false); +} + +bool +dns_name_isabsolute(const dns_name_t *name) { + /* + * Does 'name' end in the root label? + */ + + REQUIRE(VALID_NAME(name)); + + if ((name->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + return (true); + } + return (false); +} + +#define hyphenchar(c) ((c) == 0x2d) +#define asterchar(c) ((c) == 0x2a) +#define alphachar(c) \ + (((c) >= 0x41 && (c) <= 0x5a) || ((c) >= 0x61 && (c) <= 0x7a)) +#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39) +#define borderchar(c) (alphachar(c) || digitchar(c)) +#define middlechar(c) (borderchar(c) || hyphenchar(c)) +#define domainchar(c) ((c) > 0x20 && (c) < 0x7f) + +bool +dns_name_ismailbox(const dns_name_t *name) { + unsigned char *ndata, ch; + unsigned int n; + bool first; + + REQUIRE(VALID_NAME(name)); + REQUIRE(name->labels > 0); + REQUIRE(name->attributes & DNS_NAMEATTR_ABSOLUTE); + + /* + * Root label. + */ + if (name->length == 1) { + return (true); + } + + ndata = name->ndata; + n = *ndata++; + INSIST(n <= 63); + while (n--) { + ch = *ndata++; + if (!domainchar(ch)) { + return (false); + } + } + + if (ndata == name->ndata + name->length) { + return (false); + } + + /* + * RFC952/RFC1123 hostname. + */ + while (ndata < (name->ndata + name->length)) { + n = *ndata++; + INSIST(n <= 63); + first = true; + while (n--) { + ch = *ndata++; + if (first || n == 0) { + if (!borderchar(ch)) { + return (false); + } + } else { + if (!middlechar(ch)) { + return (false); + } + } + first = false; + } + } + return (true); +} + +bool +dns_name_ishostname(const dns_name_t *name, bool wildcard) { + unsigned char *ndata, ch; + unsigned int n; + bool first; + + REQUIRE(VALID_NAME(name)); + REQUIRE(name->labels > 0); + REQUIRE(name->attributes & DNS_NAMEATTR_ABSOLUTE); + + /* + * Root label. + */ + if (name->length == 1) { + return (true); + } + + /* + * Skip wildcard if this is a ownername. + */ + ndata = name->ndata; + if (wildcard && ndata[0] == 1 && ndata[1] == '*') { + ndata += 2; + } + + /* + * RFC952/RFC1123 hostname. + */ + while (ndata < (name->ndata + name->length)) { + n = *ndata++; + INSIST(n <= 63); + first = true; + while (n--) { + ch = *ndata++; + if (first || n == 0) { + if (!borderchar(ch)) { + return (false); + } + } else { + if (!middlechar(ch)) { + return (false); + } + } + first = false; + } + } + return (true); +} + +bool +dns_name_iswildcard(const dns_name_t *name) { + unsigned char *ndata; + + /* + * Is 'name' a wildcard name? + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(name->labels > 0); + + if (name->length >= 2) { + ndata = name->ndata; + if (ndata[0] == 1 && ndata[1] == '*') { + return (true); + } + } + + return (false); +} + +bool +dns_name_internalwildcard(const dns_name_t *name) { + unsigned char *ndata; + unsigned int count; + unsigned int label; + + /* + * Does 'name' contain a internal wildcard? + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(name->labels > 0); + + /* + * Skip first label. + */ + ndata = name->ndata; + count = *ndata++; + INSIST(count <= 63); + ndata += count; + label = 1; + /* + * Check all but the last of the remaining labels. + */ + while (label + 1 < name->labels) { + count = *ndata++; + INSIST(count <= 63); + if (count == 1 && *ndata == '*') { + return (true); + } + ndata += count; + label++; + } + return (false); +} + +unsigned int +dns_name_hash(const dns_name_t *name, bool case_sensitive) { + unsigned int length; + + /* + * Provide a hash value for 'name'. + */ + REQUIRE(VALID_NAME(name)); + + if (name->labels == 0) { + return (0); + } + + length = name->length; + if (length > 16) { + length = 16; + } + + /* High bits are more random. */ + return (isc_hash32(name->ndata, length, case_sensitive)); +} + +unsigned int +dns_name_fullhash(const dns_name_t *name, bool case_sensitive) { + /* + * Provide a hash value for 'name'. + */ + REQUIRE(VALID_NAME(name)); + + if (name->labels == 0) { + return (0); + } + + /* High bits are more random. */ + return (isc_hash32(name->ndata, name->length, case_sensitive)); +} + +dns_namereln_t +dns_name_fullcompare(const dns_name_t *name1, const dns_name_t *name2, + int *orderp, unsigned int *nlabelsp) { + unsigned int l1, l2, l, count1, count2, count, nlabels; + int cdiff, ldiff, chdiff; + unsigned char *label1, *label2; + unsigned char *offsets1, *offsets2; + dns_offsets_t odata1, odata2; + dns_namereln_t namereln = dns_namereln_none; + + /* + * Determine the relative ordering under the DNSSEC order relation of + * 'name1' and 'name2', and also determine the hierarchical + * relationship of the names. + * + * Note: It makes no sense for one of the names to be relative and the + * other absolute. If both names are relative, then to be meaningfully + * compared the caller must ensure that they are both relative to the + * same domain. + */ + + REQUIRE(VALID_NAME(name1)); + REQUIRE(VALID_NAME(name2)); + REQUIRE(orderp != NULL); + REQUIRE(nlabelsp != NULL); + /* + * Either name1 is absolute and name2 is absolute, or neither is. + */ + REQUIRE((name1->attributes & DNS_NAMEATTR_ABSOLUTE) == + (name2->attributes & DNS_NAMEATTR_ABSOLUTE)); + + if (name1 == name2) { + *orderp = 0; + *nlabelsp = name1->labels; + return (dns_namereln_equal); + } + + SETUP_OFFSETS(name1, offsets1, odata1); + SETUP_OFFSETS(name2, offsets2, odata2); + + nlabels = 0; + l1 = name1->labels; + l2 = name2->labels; + if (l2 > l1) { + l = l1; + ldiff = 0 - (l2 - l1); + } else { + l = l2; + ldiff = l1 - l2; + } + + offsets1 += l1; + offsets2 += l2; + + while (l > 0) { + l--; + offsets1--; + offsets2--; + label1 = &name1->ndata[*offsets1]; + label2 = &name2->ndata[*offsets2]; + count1 = *label1++; + count2 = *label2++; + + /* + * We dropped bitstring labels, and we don't support any + * other extended label types. + */ + INSIST(count1 <= 63 && count2 <= 63); + + cdiff = (int)count1 - (int)count2; + if (cdiff < 0) { + count = count1; + } else { + count = count2; + } + + /* Loop unrolled for performance */ + while (count > 3) { + chdiff = (int)maptolower[label1[0]] - + (int)maptolower[label2[0]]; + if (chdiff != 0) { + *orderp = chdiff; + goto done; + } + chdiff = (int)maptolower[label1[1]] - + (int)maptolower[label2[1]]; + if (chdiff != 0) { + *orderp = chdiff; + goto done; + } + chdiff = (int)maptolower[label1[2]] - + (int)maptolower[label2[2]]; + if (chdiff != 0) { + *orderp = chdiff; + goto done; + } + chdiff = (int)maptolower[label1[3]] - + (int)maptolower[label2[3]]; + if (chdiff != 0) { + *orderp = chdiff; + goto done; + } + count -= 4; + label1 += 4; + label2 += 4; + } + while (count-- > 0) { + chdiff = (int)maptolower[*label1++] - + (int)maptolower[*label2++]; + if (chdiff != 0) { + *orderp = chdiff; + goto done; + } + } + if (cdiff != 0) { + *orderp = cdiff; + goto done; + } + nlabels++; + } + + *orderp = ldiff; + if (ldiff < 0) { + namereln = dns_namereln_contains; + } else if (ldiff > 0) { + namereln = dns_namereln_subdomain; + } else { + namereln = dns_namereln_equal; + } + *nlabelsp = nlabels; + return (namereln); + +done: + *nlabelsp = nlabels; + if (nlabels > 0) { + namereln = dns_namereln_commonancestor; + } + + return (namereln); +} + +int +dns_name_compare(const dns_name_t *name1, const dns_name_t *name2) { + int order; + unsigned int nlabels; + + /* + * Determine the relative ordering under the DNSSEC order relation of + * 'name1' and 'name2'. + * + * Note: It makes no sense for one of the names to be relative and the + * other absolute. If both names are relative, then to be meaningfully + * compared the caller must ensure that they are both relative to the + * same domain. + */ + + (void)dns_name_fullcompare(name1, name2, &order, &nlabels); + + return (order); +} + +bool +dns_name_equal(const dns_name_t *name1, const dns_name_t *name2) { + unsigned int l, count; + unsigned char c; + unsigned char *label1, *label2; + + /* + * Are 'name1' and 'name2' equal? + * + * Note: It makes no sense for one of the names to be relative and the + * other absolute. If both names are relative, then to be meaningfully + * compared the caller must ensure that they are both relative to the + * same domain. + */ + + REQUIRE(VALID_NAME(name1)); + REQUIRE(VALID_NAME(name2)); + /* + * Either name1 is absolute and name2 is absolute, or neither is. + */ + REQUIRE((name1->attributes & DNS_NAMEATTR_ABSOLUTE) == + (name2->attributes & DNS_NAMEATTR_ABSOLUTE)); + + if (name1 == name2) { + return (true); + } + + if (name1->length != name2->length) { + return (false); + } + + l = name1->labels; + + if (l != name2->labels) { + return (false); + } + + label1 = name1->ndata; + label2 = name2->ndata; + while (l-- > 0) { + count = *label1++; + if (count != *label2++) { + return (false); + } + + INSIST(count <= 63); /* no bitstring support */ + + /* Loop unrolled for performance */ + while (count > 3) { + c = maptolower[label1[0]]; + if (c != maptolower[label2[0]]) { + return (false); + } + c = maptolower[label1[1]]; + if (c != maptolower[label2[1]]) { + return (false); + } + c = maptolower[label1[2]]; + if (c != maptolower[label2[2]]) { + return (false); + } + c = maptolower[label1[3]]; + if (c != maptolower[label2[3]]) { + return (false); + } + count -= 4; + label1 += 4; + label2 += 4; + } + while (count-- > 0) { + c = maptolower[*label1++]; + if (c != maptolower[*label2++]) { + return (false); + } + } + } + + return (true); +} + +bool +dns_name_caseequal(const dns_name_t *name1, const dns_name_t *name2) { + /* + * Are 'name1' and 'name2' equal? + * + * Note: It makes no sense for one of the names to be relative and the + * other absolute. If both names are relative, then to be meaningfully + * compared the caller must ensure that they are both relative to the + * same domain. + */ + + REQUIRE(VALID_NAME(name1)); + REQUIRE(VALID_NAME(name2)); + /* + * Either name1 is absolute and name2 is absolute, or neither is. + */ + REQUIRE((name1->attributes & DNS_NAMEATTR_ABSOLUTE) == + (name2->attributes & DNS_NAMEATTR_ABSOLUTE)); + + if (name1->length != name2->length) { + return (false); + } + + if (memcmp(name1->ndata, name2->ndata, name1->length) != 0) { + return (false); + } + + return (true); +} + +int +dns_name_rdatacompare(const dns_name_t *name1, const dns_name_t *name2) { + unsigned int l1, l2, l, count1, count2, count; + unsigned char c1, c2; + unsigned char *label1, *label2; + + /* + * Compare two absolute names as rdata. + */ + + REQUIRE(VALID_NAME(name1)); + REQUIRE(name1->labels > 0); + REQUIRE((name1->attributes & DNS_NAMEATTR_ABSOLUTE) != 0); + REQUIRE(VALID_NAME(name2)); + REQUIRE(name2->labels > 0); + REQUIRE((name2->attributes & DNS_NAMEATTR_ABSOLUTE) != 0); + + l1 = name1->labels; + l2 = name2->labels; + + l = (l1 < l2) ? l1 : l2; + + label1 = name1->ndata; + label2 = name2->ndata; + while (l > 0) { + l--; + count1 = *label1++; + count2 = *label2++; + + /* no bitstring support */ + INSIST(count1 <= 63 && count2 <= 63); + + if (count1 != count2) { + return ((count1 < count2) ? -1 : 1); + } + count = count1; + while (count > 0) { + count--; + c1 = maptolower[*label1++]; + c2 = maptolower[*label2++]; + if (c1 < c2) { + return (-1); + } else if (c1 > c2) { + return (1); + } + } + } + + /* + * If one name had more labels than the other, their common + * prefix must have been different because the shorter name + * ended with the root label and the longer one can't have + * a root label in the middle of it. Therefore, if we get + * to this point, the lengths must be equal. + */ + INSIST(l1 == l2); + + return (0); +} + +bool +dns_name_issubdomain(const dns_name_t *name1, const dns_name_t *name2) { + int order; + unsigned int nlabels; + dns_namereln_t namereln; + + /* + * Is 'name1' a subdomain of 'name2'? + * + * Note: It makes no sense for one of the names to be relative and the + * other absolute. If both names are relative, then to be meaningfully + * compared the caller must ensure that they are both relative to the + * same domain. + */ + + namereln = dns_name_fullcompare(name1, name2, &order, &nlabels); + if (namereln == dns_namereln_subdomain || + namereln == dns_namereln_equal) + { + return (true); + } + + return (false); +} + +bool +dns_name_matcheswildcard(const dns_name_t *name, const dns_name_t *wname) { + int order; + unsigned int nlabels, labels; + dns_name_t tname; + + REQUIRE(VALID_NAME(name)); + REQUIRE(name->labels > 0); + REQUIRE(VALID_NAME(wname)); + labels = wname->labels; + REQUIRE(labels > 0); + REQUIRE(dns_name_iswildcard(wname)); + + DNS_NAME_INIT(&tname, NULL); + dns_name_getlabelsequence(wname, 1, labels - 1, &tname); + if (dns_name_fullcompare(name, &tname, &order, &nlabels) == + dns_namereln_subdomain) + { + return (true); + } + return (false); +} + +unsigned int +dns_name_countlabels(const dns_name_t *name) { + /* + * How many labels does 'name' have? + */ + + REQUIRE(VALID_NAME(name)); + + ENSURE(name->labels <= 128); + + return (name->labels); +} + +void +dns_name_getlabel(const dns_name_t *name, unsigned int n, dns_label_t *label) { + unsigned char *offsets; + dns_offsets_t odata; + + /* + * Make 'label' refer to the 'n'th least significant label of 'name'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(name->labels > 0); + REQUIRE(n < name->labels); + REQUIRE(label != NULL); + + SETUP_OFFSETS(name, offsets, odata); + + label->base = &name->ndata[offsets[n]]; + if (n == name->labels - 1) { + label->length = name->length - offsets[n]; + } else { + label->length = offsets[n + 1] - offsets[n]; + } +} + +void +dns_name_getlabelsequence(const dns_name_t *source, unsigned int first, + unsigned int n, dns_name_t *target) { + unsigned char *p, l; + unsigned int firstoffset, endoffset; + unsigned int i; + + /* + * Make 'target' refer to the 'n' labels including and following + * 'first' in 'source'. + */ + + REQUIRE(VALID_NAME(source)); + REQUIRE(VALID_NAME(target)); + REQUIRE(first <= source->labels); + REQUIRE(n <= source->labels - first); /* note first+n could overflow */ + REQUIRE(BINDABLE(target)); + + p = source->ndata; + if (first == source->labels) { + firstoffset = source->length; + } else { + for (i = 0; i < first; i++) { + l = *p; + p += l + 1; + } + firstoffset = (unsigned int)(p - source->ndata); + } + + if (first + n == source->labels) { + endoffset = source->length; + } else { + for (i = 0; i < n; i++) { + l = *p; + p += l + 1; + } + endoffset = (unsigned int)(p - source->ndata); + } + + target->ndata = &source->ndata[firstoffset]; + target->length = endoffset - firstoffset; + + if (first + n == source->labels && n > 0 && + (source->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) + { + target->attributes |= DNS_NAMEATTR_ABSOLUTE; + } else { + target->attributes &= ~DNS_NAMEATTR_ABSOLUTE; + } + + target->labels = n; + + /* + * If source and target are the same, and we're making target + * a prefix of source, the offsets table is correct already + * so we don't need to call set_offsets(). + */ + if (target->offsets != NULL && (target != source || first != 0)) { + set_offsets(target, target->offsets, NULL); + } +} + +void +dns_name_clone(const dns_name_t *source, dns_name_t *target) { + /* + * Make 'target' refer to the same name as 'source'. + */ + + REQUIRE(VALID_NAME(source)); + REQUIRE(VALID_NAME(target)); + REQUIRE(BINDABLE(target)); + + target->ndata = source->ndata; + target->length = source->length; + target->labels = source->labels; + target->attributes = source->attributes & + (unsigned int)~(DNS_NAMEATTR_READONLY | + DNS_NAMEATTR_DYNAMIC | + DNS_NAMEATTR_DYNOFFSETS); + if (target->offsets != NULL && source->labels > 0) { + if (source->offsets != NULL) { + memmove(target->offsets, source->offsets, + source->labels); + } else { + set_offsets(target, target->offsets, NULL); + } + } +} + +void +dns_name_fromregion(dns_name_t *name, const isc_region_t *r) { + unsigned char *offsets; + dns_offsets_t odata; + unsigned int len; + isc_region_t r2; + + /* + * Make 'name' refer to region 'r'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(r != NULL); + REQUIRE(BINDABLE(name)); + + INIT_OFFSETS(name, offsets, odata); + + if (name->buffer != NULL) { + isc_buffer_clear(name->buffer); + isc_buffer_availableregion(name->buffer, &r2); + len = (r->length < r2.length) ? r->length : r2.length; + if (len > DNS_NAME_MAXWIRE) { + len = DNS_NAME_MAXWIRE; + } + if (len != 0) { + memmove(r2.base, r->base, len); + } + name->ndata = r2.base; + name->length = len; + } else { + name->ndata = r->base; + name->length = (r->length <= DNS_NAME_MAXWIRE) + ? r->length + : DNS_NAME_MAXWIRE; + } + + if (r->length > 0) { + set_offsets(name, offsets, name); + } else { + name->labels = 0; + name->attributes &= ~DNS_NAMEATTR_ABSOLUTE; + } + + if (name->buffer != NULL) { + isc_buffer_add(name->buffer, name->length); + } +} + +void +dns_name_toregion(const dns_name_t *name, isc_region_t *r) { + /* + * Make 'r' refer to 'name'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(r != NULL); + + DNS_NAME_TOREGION(name, r); +} + +isc_result_t +dns_name_fromtext(dns_name_t *name, isc_buffer_t *source, + const dns_name_t *origin, unsigned int options, + isc_buffer_t *target) { + unsigned char *ndata, *label = NULL; + char *tdata; + char c; + ft_state state; + unsigned int value = 0, count = 0; + unsigned int n1 = 0, n2 = 0; + unsigned int tlen, nrem, nused, digits = 0, labels, tused; + bool done; + unsigned char *offsets; + dns_offsets_t odata; + bool downcase; + + /* + * Convert the textual representation of a DNS name at source + * into uncompressed wire form stored in target. + * + * Notes: + * Relative domain names will have 'origin' appended to them + * unless 'origin' is NULL, in which case relative domain names + * will remain relative. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(ISC_BUFFER_VALID(source)); + REQUIRE((target != NULL && ISC_BUFFER_VALID(target)) || + (target == NULL && ISC_BUFFER_VALID(name->buffer))); + + downcase = ((options & DNS_NAME_DOWNCASE) != 0); + + if (target == NULL && name->buffer != NULL) { + target = name->buffer; + isc_buffer_clear(target); + } + + REQUIRE(BINDABLE(name)); + + INIT_OFFSETS(name, offsets, odata); + offsets[0] = 0; + + /* + * Make 'name' empty in case of failure. + */ + MAKE_EMPTY(name); + + /* + * Set up the state machine. + */ + tdata = (char *)source->base + source->current; + tlen = isc_buffer_remaininglength(source); + tused = 0; + ndata = isc_buffer_used(target); + nrem = isc_buffer_availablelength(target); + if (nrem > 255) { + nrem = 255; + } + nused = 0; + labels = 0; + done = false; + state = ft_init; + + while (nrem > 0 && tlen > 0 && !done) { + c = *tdata++; + tlen--; + tused++; + + switch (state) { + case ft_init: + /* + * Is this the root name? + */ + if (c == '.') { + if (tlen != 0) { + return (DNS_R_EMPTYLABEL); + } + labels++; + *ndata++ = 0; + nrem--; + nused++; + done = true; + break; + } + if (c == '@' && tlen == 0) { + state = ft_at; + break; + } + + FALLTHROUGH; + case ft_start: + label = ndata; + ndata++; + nrem--; + nused++; + count = 0; + if (c == '\\') { + state = ft_initialescape; + break; + } + state = ft_ordinary; + if (nrem == 0) { + return (ISC_R_NOSPACE); + } + FALLTHROUGH; + case ft_ordinary: + if (c == '.') { + if (count == 0) { + return (DNS_R_EMPTYLABEL); + } + *label = count; + labels++; + INSIST(labels <= 127); + offsets[labels] = nused; + if (tlen == 0) { + labels++; + *ndata++ = 0; + nrem--; + nused++; + done = true; + } + state = ft_start; + } else if (c == '\\') { + state = ft_escape; + } else { + if (count >= 63) { + return (DNS_R_LABELTOOLONG); + } + count++; + CONVERTTOASCII(c); + if (downcase) { + c = maptolower[c & 0xff]; + } + *ndata++ = c; + nrem--; + nused++; + } + break; + case ft_initialescape: + if (c == '[') { + /* + * This looks like a bitstring label, which + * was deprecated. Intentionally drop it. + */ + return (DNS_R_BADLABELTYPE); + } + state = ft_escape; + POST(state); + FALLTHROUGH; + case ft_escape: + if (!isdigit((unsigned char)c)) { + if (count >= 63) { + return (DNS_R_LABELTOOLONG); + } + count++; + CONVERTTOASCII(c); + if (downcase) { + c = maptolower[c & 0xff]; + } + *ndata++ = c; + nrem--; + nused++; + state = ft_ordinary; + break; + } + digits = 0; + value = 0; + state = ft_escdecimal; + FALLTHROUGH; + case ft_escdecimal: + if (!isdigit((unsigned char)c)) { + return (DNS_R_BADESCAPE); + } + value *= 10; + value += digitvalue[c & 0xff]; + digits++; + if (digits == 3) { + if (value > 255) { + return (DNS_R_BADESCAPE); + } + if (count >= 63) { + return (DNS_R_LABELTOOLONG); + } + count++; + if (downcase) { + value = maptolower[value]; + } + *ndata++ = value; + nrem--; + nused++; + state = ft_ordinary; + } + break; + default: + FATAL_ERROR("Unexpected state %d", state); + /* Does not return. */ + } + } + + if (!done) { + if (nrem == 0) { + return (ISC_R_NOSPACE); + } + INSIST(tlen == 0); + if (state != ft_ordinary && state != ft_at) { + return (ISC_R_UNEXPECTEDEND); + } + if (state == ft_ordinary) { + INSIST(count != 0); + INSIST(label != NULL); + *label = count; + labels++; + INSIST(labels <= 127); + offsets[labels] = nused; + } + if (origin != NULL) { + if (nrem < origin->length) { + return (ISC_R_NOSPACE); + } + label = origin->ndata; + n1 = origin->length; + nrem -= n1; + POST(nrem); + while (n1 > 0) { + n2 = *label++; + INSIST(n2 <= 63); /* no bitstring support */ + *ndata++ = n2; + n1 -= n2 + 1; + nused += n2 + 1; + while (n2 > 0) { + c = *label++; + if (downcase) { + c = maptolower[c & 0xff]; + } + *ndata++ = c; + n2--; + } + labels++; + if (n1 > 0) { + INSIST(labels <= 127); + offsets[labels] = nused; + } + } + if ((origin->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + name->attributes |= DNS_NAMEATTR_ABSOLUTE; + } + } + } else { + name->attributes |= DNS_NAMEATTR_ABSOLUTE; + } + + name->ndata = (unsigned char *)target->base + target->used; + name->labels = labels; + name->length = nused; + + isc_buffer_forward(source, tused); + isc_buffer_add(target, name->length); + + return (ISC_R_SUCCESS); +} + +isc_result_t +dns_name_totext(const dns_name_t *name, bool omit_final_dot, + isc_buffer_t *target) { + unsigned int options = DNS_NAME_MASTERFILE; + + if (omit_final_dot) { + options |= DNS_NAME_OMITFINALDOT; + } + return (dns_name_totext2(name, options, target)); +} + +isc_result_t +dns_name_toprincipal(const dns_name_t *name, isc_buffer_t *target) { + return (dns_name_totext2(name, DNS_NAME_OMITFINALDOT, target)); +} + +isc_result_t +dns_name_totext2(const dns_name_t *name, unsigned int options, + isc_buffer_t *target) { + unsigned char *ndata; + char *tdata; + unsigned int nlen, tlen; + unsigned char c; + unsigned int trem, count; + unsigned int labels; + bool saw_root = false; + unsigned int oused; + bool omit_final_dot = ((options & DNS_NAME_OMITFINALDOT) != 0); + + /* + * This function assumes the name is in proper uncompressed + * wire format. + */ + REQUIRE(VALID_NAME(name)); + REQUIRE(ISC_BUFFER_VALID(target)); + + oused = target->used; + + ndata = name->ndata; + nlen = name->length; + labels = name->labels; + tdata = isc_buffer_used(target); + tlen = isc_buffer_availablelength(target); + + trem = tlen; + + if (labels == 0 && nlen == 0) { + /* + * Special handling for an empty name. + */ + if (trem == 0) { + return (ISC_R_NOSPACE); + } + + /* + * The names of these booleans are misleading in this case. + * This empty name is not necessarily from the root node of + * the DNS root zone, nor is a final dot going to be included. + * They need to be set this way, though, to keep the "@" + * from being trounced. + */ + saw_root = true; + omit_final_dot = false; + *tdata++ = '@'; + trem--; + + /* + * Skip the while() loop. + */ + nlen = 0; + } else if (nlen == 1 && labels == 1 && *ndata == '\0') { + /* + * Special handling for the root label. + */ + if (trem == 0) { + return (ISC_R_NOSPACE); + } + + saw_root = true; + omit_final_dot = false; + *tdata++ = '.'; + trem--; + + /* + * Skip the while() loop. + */ + nlen = 0; + } + + while (labels > 0 && nlen > 0 && trem > 0) { + labels--; + count = *ndata++; + nlen--; + if (count == 0) { + saw_root = true; + break; + } + if (count < 64) { + INSIST(nlen >= count); + while (count > 0) { + c = *ndata; + switch (c) { + /* Special modifiers in zone files. */ + case 0x40: /* '@' */ + case 0x24: /* '$' */ + if ((options & DNS_NAME_MASTERFILE) == + 0) + { + goto no_escape; + } + FALLTHROUGH; + case 0x22: /* '"' */ + case 0x28: /* '(' */ + case 0x29: /* ')' */ + case 0x2E: /* '.' */ + case 0x3B: /* ';' */ + case 0x5C: /* '\\' */ + if (trem < 2) { + return (ISC_R_NOSPACE); + } + *tdata++ = '\\'; + CONVERTFROMASCII(c); + *tdata++ = c; + ndata++; + trem -= 2; + nlen--; + break; + no_escape: + default: + if (c > 0x20 && c < 0x7f) { + if (trem == 0) { + return (ISC_R_NOSPACE); + } + CONVERTFROMASCII(c); + *tdata++ = c; + ndata++; + trem--; + nlen--; + } else { + if (trem < 4) { + return (ISC_R_NOSPACE); + } + *tdata++ = 0x5c; + *tdata++ = 0x30 + + ((c / 100) % 10); + *tdata++ = 0x30 + + ((c / 10) % 10); + *tdata++ = 0x30 + (c % 10); + trem -= 4; + ndata++; + nlen--; + } + } + count--; + } + } else { + FATAL_ERROR("Unexpected label type %02x", count); + UNREACHABLE(); + } + + /* + * The following assumes names are absolute. If not, we + * fix things up later. Note that this means that in some + * cases one more byte of text buffer is required than is + * needed in the final output. + */ + if (trem == 0) { + return (ISC_R_NOSPACE); + } + *tdata++ = '.'; + trem--; + } + + if (nlen != 0 && trem == 0) { + return (ISC_R_NOSPACE); + } + + if (!saw_root || omit_final_dot) { + trem++; + tdata--; + } + if (trem > 0) { + *tdata = 0; + } + isc_buffer_add(target, tlen - trem); + + if (totext_filter_proc != NULL) { + return ((totext_filter_proc)(target, oused)); + } + + return (ISC_R_SUCCESS); +} + +isc_result_t +dns_name_tofilenametext(const dns_name_t *name, bool omit_final_dot, + isc_buffer_t *target) { + unsigned char *ndata; + char *tdata; + unsigned int nlen, tlen; + unsigned char c; + unsigned int trem, count; + unsigned int labels; + + /* + * This function assumes the name is in proper uncompressed + * wire format. + */ + REQUIRE(VALID_NAME(name)); + REQUIRE((name->attributes & DNS_NAMEATTR_ABSOLUTE) != 0); + REQUIRE(ISC_BUFFER_VALID(target)); + + ndata = name->ndata; + nlen = name->length; + labels = name->labels; + tdata = isc_buffer_used(target); + tlen = isc_buffer_availablelength(target); + + trem = tlen; + + if (nlen == 1 && labels == 1 && *ndata == '\0') { + /* + * Special handling for the root label. + */ + if (trem == 0) { + return (ISC_R_NOSPACE); + } + + omit_final_dot = false; + *tdata++ = '.'; + trem--; + + /* + * Skip the while() loop. + */ + nlen = 0; + } + + while (labels > 0 && nlen > 0 && trem > 0) { + labels--; + count = *ndata++; + nlen--; + if (count == 0) { + break; + } + if (count < 64) { + INSIST(nlen >= count); + while (count > 0) { + c = *ndata; + if ((c >= 0x30 && c <= 0x39) || /* digit */ + (c >= 0x41 && c <= 0x5A) || /* uppercase */ + (c >= 0x61 && c <= 0x7A) || /* lowercase */ + c == 0x2D || /* hyphen */ + c == 0x5F) /* underscore */ + { + if (trem == 0) { + return (ISC_R_NOSPACE); + } + /* downcase */ + if (c >= 0x41 && c <= 0x5A) { + c += 0x20; + } + CONVERTFROMASCII(c); + *tdata++ = c; + ndata++; + trem--; + nlen--; + } else { + if (trem < 4) { + return (ISC_R_NOSPACE); + } + snprintf(tdata, trem, "%%%02X", c); + tdata += 3; + trem -= 3; + ndata++; + nlen--; + } + count--; + } + } else { + FATAL_ERROR("Unexpected label type %02x", count); + UNREACHABLE(); + } + + /* + * The following assumes names are absolute. If not, we + * fix things up later. Note that this means that in some + * cases one more byte of text buffer is required than is + * needed in the final output. + */ + if (trem == 0) { + return (ISC_R_NOSPACE); + } + *tdata++ = '.'; + trem--; + } + + if (nlen != 0 && trem == 0) { + return (ISC_R_NOSPACE); + } + + if (omit_final_dot) { + trem++; + } + + isc_buffer_add(target, tlen - trem); + + return (ISC_R_SUCCESS); +} + +isc_result_t +dns_name_downcase(const dns_name_t *source, dns_name_t *name, + isc_buffer_t *target) { + unsigned char *sndata, *ndata; + unsigned int nlen, count, labels; + isc_buffer_t buffer; + + /* + * Downcase 'source'. + */ + + REQUIRE(VALID_NAME(source)); + REQUIRE(VALID_NAME(name)); + if (source == name) { + REQUIRE((name->attributes & DNS_NAMEATTR_READONLY) == 0); + isc_buffer_init(&buffer, source->ndata, source->length); + target = &buffer; + ndata = source->ndata; + } else { + REQUIRE(BINDABLE(name)); + REQUIRE((target != NULL && ISC_BUFFER_VALID(target)) || + (target == NULL && ISC_BUFFER_VALID(name->buffer))); + if (target == NULL) { + target = name->buffer; + isc_buffer_clear(name->buffer); + } + ndata = (unsigned char *)target->base + target->used; + name->ndata = ndata; + } + + sndata = source->ndata; + nlen = source->length; + labels = source->labels; + + if (nlen > (target->length - target->used)) { + MAKE_EMPTY(name); + return (ISC_R_NOSPACE); + } + + while (labels > 0 && nlen > 0) { + labels--; + count = *sndata++; + *ndata++ = count; + nlen--; + if (count < 64) { + INSIST(nlen >= count); + while (count > 0) { + *ndata++ = maptolower[(*sndata++)]; + nlen--; + count--; + } + } else { + FATAL_ERROR("Unexpected label type %02x", count); + /* Does not return. */ + } + } + + if (source != name) { + name->labels = source->labels; + name->length = source->length; + if ((source->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + name->attributes = DNS_NAMEATTR_ABSOLUTE; + } else { + name->attributes = 0; + } + if (name->labels > 0 && name->offsets != NULL) { + set_offsets(name, name->offsets, NULL); + } + } + + isc_buffer_add(target, name->length); + + return (ISC_R_SUCCESS); +} + +static void +set_offsets(const dns_name_t *name, unsigned char *offsets, + dns_name_t *set_name) { + unsigned int offset, count, length, nlabels; + unsigned char *ndata; + bool absolute; + + ndata = name->ndata; + length = name->length; + offset = 0; + nlabels = 0; + absolute = false; + while (offset != length) { + INSIST(nlabels < 128); + offsets[nlabels++] = offset; + count = *ndata; + INSIST(count <= 63); + offset += count + 1; + ndata += count + 1; + INSIST(offset <= length); + if (count == 0) { + absolute = true; + break; + } + } + if (set_name != NULL) { + INSIST(set_name == name); + + set_name->labels = nlabels; + set_name->length = offset; + if (absolute) { + set_name->attributes |= DNS_NAMEATTR_ABSOLUTE; + } else { + set_name->attributes &= ~DNS_NAMEATTR_ABSOLUTE; + } + } + INSIST(nlabels == name->labels); + INSIST(offset == name->length); +} + +isc_result_t +dns_name_fromwire(dns_name_t *const name, isc_buffer_t *const source, + dns_decompress_t *const dctx, unsigned int options, + isc_buffer_t *target) { + /* + * Copy the name at source into target, decompressing it. + * + * *** WARNING *** + * + * dns_name_fromwire() deals with raw network data. An error in this + * routine could result in the failure or hijacking of the server. + * + * The description of name compression in RFC 1035 section 4.1.4 is + * subtle wrt certain edge cases. The first important sentence is: + * + * > In this scheme, an entire domain name or a list of labels at the + * > end of a domain name is replaced with a pointer to a prior + * > occurance of the same name. + * + * The key word is "prior". This says that compression pointers must + * point strictly earlier in the message (before our "marker" variable), + * which is enough to prevent DoS attacks due to compression loops. + * + * The next important sentence is: + * + * > If a domain name is contained in a part of the message subject to a + * > length field (such as the RDATA section of an RR), and compression + * > is used, the length of the compressed name is used in the length + * > calculation, rather than the length of the expanded name. + * + * When decompressing, this means that the amount of the source buffer + * that we consumed (which is checked wrt the container's length field) + * is the length of the compressed name. A compressed name is defined as + * a sequence of labels ending with the root label or a compression + * pointer, that is, the segment of the name that dns_name_fromwire() + * examines first. + * + * This matters when handling names that play dirty tricks, like: + * + * +---+---+---+---+---+---+ + * | 4 | 1 |'a'|192| 0 | 0 | + * +---+---+---+---+---+---+ + * + * We start at octet 1. There is an ordinary single character label "a", + * followed by a compression pointer that refers back to octet zero. + * Here there is a label of length 4, which weirdly re-uses the octets + * we already examined as the data for the label. It is followed by the + * root label, + * + * The specification says that the compressed name ends after the first + * zero octet (after the compression pointer) not the second zero octet, + * even though the second octet is later in the message. This shows the + * correct way to set our "consumed" variable. + */ + + REQUIRE((options & DNS_NAME_DOWNCASE) == 0); + REQUIRE(VALID_NAME(name)); + REQUIRE(BINDABLE(name)); + REQUIRE(dctx != NULL); + REQUIRE((target != NULL && ISC_BUFFER_VALID(target)) || + (target == NULL && ISC_BUFFER_VALID(name->buffer))); + + if (target == NULL && name->buffer != NULL) { + target = name->buffer; + isc_buffer_clear(target); + } + + uint8_t *const name_buf = isc_buffer_used(target); + const uint32_t name_max = ISC_MIN(DNS_NAME_MAXWIRE, + isc_buffer_availablelength(target)); + uint32_t name_len = 0; + MAKE_EMPTY(name); /* in case of failure */ + + dns_offsets_t odata; + uint8_t *offsets = NULL; + uint32_t labels = 0; + INIT_OFFSETS(name, offsets, odata); + + /* + * After chasing a compression pointer, these variables refer to the + * source buffer as follows: + * + * sb --- mr --- cr --- st --- cd --- sm + * + * sb = source_buf (const) + * mr = marker + * cr = cursor + * st = start (const) + * cd = consumed + * sm = source_max (const) + * + * The marker hops backwards for each pointer. + * The cursor steps forwards for each label. + * The amount of the source we consumed is set once. + */ + const uint8_t *const source_buf = isc_buffer_base(source); + const uint8_t *const source_max = isc_buffer_used(source); + const uint8_t *const start = isc_buffer_current(source); + const uint8_t *marker = start; + const uint8_t *cursor = start; + const uint8_t *consumed = NULL; + + /* + * One iteration per label. + */ + while (cursor < source_max) { + const uint8_t label_len = *cursor++; + if (label_len < 64) { + /* + * Normal label: record its offset, and check bounds on + * the name length, which also ensures we don't overrun + * the offsets array. Don't touch any source bytes yet! + * The source bounds check will happen when we loop. + */ + offsets[labels++] = name_len; + /* and then a step to the ri-i-i-i-i-ight */ + cursor += label_len; + name_len += label_len + 1; + if (name_len > name_max) { + return (name_max == DNS_NAME_MAXWIRE + ? DNS_R_NAMETOOLONG + : ISC_R_NOSPACE); + } else if (label_len == 0) { + goto root_label; + } + } else if (label_len < 192) { + return (DNS_R_BADLABELTYPE); + } else if ((dctx->allowed & DNS_COMPRESS_GLOBAL14) == 0) { + return (DNS_R_DISALLOWED); + } else if (cursor < source_max) { + /* + * Compression pointer. Ensure it does not loop. + * + * Copy multiple labels in one go, to make the most of + * memmove() performance. Start at the marker and finish + * just before the pointer's hi+lo bytes, before the + * cursor. Bounds were already checked. + */ + const uint32_t hi = label_len & 0x3F; + const uint32_t lo = *cursor++; + const uint8_t *pointer = source_buf + (256 * hi + lo); + if (pointer >= marker) { + return (DNS_R_BADPOINTER); + } + const uint32_t copy_len = (cursor - 2) - marker; + uint8_t *const dest = name_buf + name_len - copy_len; + memmove(dest, marker, copy_len); + consumed = consumed != NULL ? consumed : cursor; + /* it's just a jump to the left */ + cursor = marker = pointer; + } + } + return (ISC_R_UNEXPECTEDEND); +root_label:; + /* + * Copy labels almost like we do for compression pointers, + * from the marker up to and including the root label. + */ + const uint32_t copy_len = cursor - marker; + memmove(name_buf + name_len - copy_len, marker, copy_len); + consumed = consumed != NULL ? consumed : cursor; + isc_buffer_forward(source, consumed - start); + + name->attributes |= DNS_NAMEATTR_ABSOLUTE; + name->ndata = name_buf; + name->labels = labels; + name->length = name_len; + isc_buffer_add(target, name_len); + + return (ISC_R_SUCCESS); +} + +isc_result_t +dns_name_towire(const dns_name_t *name, dns_compress_t *cctx, + isc_buffer_t *target) { + return (dns_name_towire2(name, cctx, target, NULL)); +} + +isc_result_t +dns_name_towire2(const dns_name_t *name, dns_compress_t *cctx, + isc_buffer_t *target, uint16_t *comp_offsetp) { + unsigned int methods; + uint16_t offset; + dns_name_t gp; /* Global compression prefix */ + bool gf; /* Global compression target found */ + uint16_t go; /* Global compression offset */ + dns_offsets_t clo; + dns_name_t clname; + + /* + * Convert 'name' into wire format, compressing it as specified by the + * compression context 'cctx', and storing the result in 'target'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(cctx != NULL); + REQUIRE(ISC_BUFFER_VALID(target)); + + /* + * If this exact name was already rendered before, and the + * offset of the previously rendered name is passed to us, write + * a compression pointer directly. + */ + methods = dns_compress_getmethods(cctx); + if (comp_offsetp != NULL && *comp_offsetp < 0x4000 && + (name->attributes & DNS_NAMEATTR_NOCOMPRESS) == 0 && + (methods & DNS_COMPRESS_GLOBAL14) != 0) + { + if (target->length - target->used < 2) { + return (ISC_R_NOSPACE); + } + offset = *comp_offsetp; + offset |= 0xc000; + isc_buffer_putuint16(target, offset); + return (ISC_R_SUCCESS); + } + + /* + * If 'name' doesn't have an offsets table, make a clone which + * has one. + */ + if (name->offsets == NULL) { + DNS_NAME_INIT(&clname, clo); + dns_name_clone(name, &clname); + name = &clname; + } + DNS_NAME_INIT(&gp, NULL); + + offset = target->used; /*XXX*/ + + if ((name->attributes & DNS_NAMEATTR_NOCOMPRESS) == 0 && + (methods & DNS_COMPRESS_GLOBAL14) != 0) + { + gf = dns_compress_findglobal(cctx, name, &gp, &go); + } else { + gf = false; + } + + /* + * If the offset is too high for 14 bit global compression, we're + * out of luck. + */ + if (gf && go >= 0x4000) { + gf = false; + } + + /* + * Will the compression pointer reduce the message size? + */ + if (gf && (gp.length + 2) >= name->length) { + gf = false; + } + + if (gf) { + if (target->length - target->used < gp.length) { + return (ISC_R_NOSPACE); + } + if (gp.length != 0) { + unsigned char *base = target->base; + (void)memmove(base + target->used, gp.ndata, + (size_t)gp.length); + } + isc_buffer_add(target, gp.length); + if (target->length - target->used < 2) { + return (ISC_R_NOSPACE); + } + isc_buffer_putuint16(target, go | 0xc000); + if (gp.length != 0) { + dns_compress_add(cctx, name, &gp, offset); + if (comp_offsetp != NULL) { + *comp_offsetp = offset; + } + } else if (comp_offsetp != NULL) { + *comp_offsetp = go; + } + } else { + if (target->length - target->used < name->length) { + return (ISC_R_NOSPACE); + } + if (name->length != 0) { + unsigned char *base = target->base; + (void)memmove(base + target->used, name->ndata, + (size_t)name->length); + } + isc_buffer_add(target, name->length); + dns_compress_add(cctx, name, name, offset); + if (comp_offsetp != NULL) { + *comp_offsetp = offset; + } + } + + return (ISC_R_SUCCESS); +} + +isc_result_t +dns_name_concatenate(const dns_name_t *prefix, const dns_name_t *suffix, + dns_name_t *name, isc_buffer_t *target) { + unsigned char *ndata, *offsets; + unsigned int nrem, labels, prefix_length, length; + bool copy_prefix = true; + bool copy_suffix = true; + bool absolute = false; + dns_name_t tmp_name; + dns_offsets_t odata; + + /* + * Concatenate 'prefix' and 'suffix'. + */ + + REQUIRE(prefix == NULL || VALID_NAME(prefix)); + REQUIRE(suffix == NULL || VALID_NAME(suffix)); + REQUIRE(name == NULL || VALID_NAME(name)); + REQUIRE((target != NULL && ISC_BUFFER_VALID(target)) || + (target == NULL && name != NULL && + ISC_BUFFER_VALID(name->buffer))); + if (prefix == NULL || prefix->labels == 0) { + copy_prefix = false; + } + if (suffix == NULL || suffix->labels == 0) { + copy_suffix = false; + } + if (copy_prefix && (prefix->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + absolute = true; + REQUIRE(!copy_suffix); + } + if (name == NULL) { + DNS_NAME_INIT(&tmp_name, odata); + name = &tmp_name; + } + if (target == NULL) { + INSIST(name->buffer != NULL); + target = name->buffer; + isc_buffer_clear(name->buffer); + } + + REQUIRE(BINDABLE(name)); + + /* + * Set up. + */ + nrem = target->length - target->used; + ndata = (unsigned char *)target->base + target->used; + if (nrem > DNS_NAME_MAXWIRE) { + nrem = DNS_NAME_MAXWIRE; + } + length = 0; + prefix_length = 0; + labels = 0; + if (copy_prefix) { + prefix_length = prefix->length; + length += prefix_length; + labels += prefix->labels; + } + if (copy_suffix) { + length += suffix->length; + labels += suffix->labels; + } + if (length > DNS_NAME_MAXWIRE) { + MAKE_EMPTY(name); + return (DNS_R_NAMETOOLONG); + } + if (length > nrem) { + MAKE_EMPTY(name); + return (ISC_R_NOSPACE); + } + + if (copy_suffix) { + if ((suffix->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + absolute = true; + } + memmove(ndata + prefix_length, suffix->ndata, suffix->length); + } + + /* + * If 'prefix' and 'name' are the same object, and the object has + * a dedicated buffer, and we're using it, then we don't have to + * copy anything. + */ + if (copy_prefix && (prefix != name || prefix->buffer != target)) { + memmove(ndata, prefix->ndata, prefix_length); + } + + name->ndata = ndata; + name->labels = labels; + name->length = length; + if (absolute) { + name->attributes = DNS_NAMEATTR_ABSOLUTE; + } else { + name->attributes = 0; + } + + if (name->labels > 0 && name->offsets != NULL) { + INIT_OFFSETS(name, offsets, odata); + set_offsets(name, offsets, NULL); + } + + isc_buffer_add(target, name->length); + + return (ISC_R_SUCCESS); +} + +void +dns_name_split(const dns_name_t *name, unsigned int suffixlabels, + dns_name_t *prefix, dns_name_t *suffix) + +{ + unsigned int splitlabel; + + REQUIRE(VALID_NAME(name)); + REQUIRE(suffixlabels > 0); + REQUIRE(suffixlabels <= name->labels); + REQUIRE(prefix != NULL || suffix != NULL); + REQUIRE(prefix == NULL || (VALID_NAME(prefix) && BINDABLE(prefix))); + REQUIRE(suffix == NULL || (VALID_NAME(suffix) && BINDABLE(suffix))); + + splitlabel = name->labels - suffixlabels; + + if (prefix != NULL) { + dns_name_getlabelsequence(name, 0, splitlabel, prefix); + } + + if (suffix != NULL) { + dns_name_getlabelsequence(name, splitlabel, suffixlabels, + suffix); + } + + return; +} + +void +dns_name_dup(const dns_name_t *source, isc_mem_t *mctx, dns_name_t *target) { + /* + * Make 'target' a dynamically allocated copy of 'source'. + */ + + REQUIRE(VALID_NAME(source)); + REQUIRE(source->length > 0); + REQUIRE(VALID_NAME(target)); + REQUIRE(BINDABLE(target)); + + /* + * Make 'target' empty in case of failure. + */ + MAKE_EMPTY(target); + + target->ndata = isc_mem_get(mctx, source->length); + + memmove(target->ndata, source->ndata, source->length); + + target->length = source->length; + target->labels = source->labels; + target->attributes = DNS_NAMEATTR_DYNAMIC; + if ((source->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + target->attributes |= DNS_NAMEATTR_ABSOLUTE; + } + if (target->offsets != NULL) { + if (source->offsets != NULL) { + memmove(target->offsets, source->offsets, + source->labels); + } else { + set_offsets(target, target->offsets, NULL); + } + } +} + +isc_result_t +dns_name_dupwithoffsets(const dns_name_t *source, isc_mem_t *mctx, + dns_name_t *target) { + /* + * Make 'target' a read-only dynamically allocated copy of 'source'. + * 'target' will also have a dynamically allocated offsets table. + */ + + REQUIRE(VALID_NAME(source)); + REQUIRE(source->length > 0); + REQUIRE(VALID_NAME(target)); + REQUIRE(BINDABLE(target)); + REQUIRE(target->offsets == NULL); + + /* + * Make 'target' empty in case of failure. + */ + MAKE_EMPTY(target); + + target->ndata = isc_mem_get(mctx, source->length + source->labels); + + memmove(target->ndata, source->ndata, source->length); + + target->length = source->length; + target->labels = source->labels; + target->attributes = DNS_NAMEATTR_DYNAMIC | DNS_NAMEATTR_DYNOFFSETS | + DNS_NAMEATTR_READONLY; + if ((source->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + target->attributes |= DNS_NAMEATTR_ABSOLUTE; + } + target->offsets = target->ndata + source->length; + if (source->offsets != NULL) { + memmove(target->offsets, source->offsets, source->labels); + } else { + set_offsets(target, target->offsets, NULL); + } + + return (ISC_R_SUCCESS); +} + +void +dns_name_free(dns_name_t *name, isc_mem_t *mctx) { + size_t size; + + /* + * Free 'name'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE((name->attributes & DNS_NAMEATTR_DYNAMIC) != 0); + + size = name->length; + if ((name->attributes & DNS_NAMEATTR_DYNOFFSETS) != 0) { + size += name->labels; + } + isc_mem_put(mctx, name->ndata, size); + dns_name_invalidate(name); +} + +isc_result_t +dns_name_digest(const dns_name_t *name, dns_digestfunc_t digest, void *arg) { + dns_name_t downname; + unsigned char data[256]; + isc_buffer_t buffer; + isc_result_t result; + isc_region_t r; + + /* + * Send 'name' in DNSSEC canonical form to 'digest'. + */ + + REQUIRE(VALID_NAME(name)); + REQUIRE(digest != NULL); + + DNS_NAME_INIT(&downname, NULL); + + isc_buffer_init(&buffer, data, sizeof(data)); + + result = dns_name_downcase(name, &downname, &buffer); + if (result != ISC_R_SUCCESS) { + return (result); + } + + isc_buffer_usedregion(&buffer, &r); + + return ((digest)(arg, &r)); +} + +bool +dns_name_dynamic(const dns_name_t *name) { + REQUIRE(VALID_NAME(name)); + + /* + * Returns whether there is dynamic memory associated with this name. + */ + + return ((name->attributes & DNS_NAMEATTR_DYNAMIC) != 0 ? true : false); +} + +isc_result_t +dns_name_print(const dns_name_t *name, FILE *stream) { + isc_result_t result; + isc_buffer_t b; + isc_region_t r; + char t[1024]; + + /* + * Print 'name' on 'stream'. + */ + + REQUIRE(VALID_NAME(name)); + + isc_buffer_init(&b, t, sizeof(t)); + result = dns_name_totext(name, false, &b); + if (result != ISC_R_SUCCESS) { + return (result); + } + isc_buffer_usedregion(&b, &r); + fprintf(stream, "%.*s", (int)r.length, (char *)r.base); + + return (ISC_R_SUCCESS); +} + +isc_result_t +dns_name_settotextfilter(dns_name_totextfilter_t *proc) { + /* + * If we already have been here set / clear as appropriate. + */ + if (totext_filter_proc != NULL && proc != NULL) { + if (totext_filter_proc == proc) { + return (ISC_R_SUCCESS); + } + } + if (proc == NULL && totext_filter_proc != NULL) { + totext_filter_proc = NULL; + return (ISC_R_SUCCESS); + } + + totext_filter_proc = proc; + + return (ISC_R_SUCCESS); +} + +void +dns_name_format(const dns_name_t *name, char *cp, unsigned int size) { + isc_result_t result; + isc_buffer_t buf; + + REQUIRE(size > 0); + + /* + * Leave room for null termination after buffer. + */ + isc_buffer_init(&buf, cp, size - 1); + result = dns_name_totext(name, true, &buf); + if (result == ISC_R_SUCCESS) { + isc_buffer_putuint8(&buf, (uint8_t)'\0'); + } else { + snprintf(cp, size, "<unknown>"); + } +} + +/* + * dns_name_tostring() -- similar to dns_name_format() but allocates its own + * memory. + */ +isc_result_t +dns_name_tostring(const dns_name_t *name, char **target, isc_mem_t *mctx) { + isc_result_t result; + isc_buffer_t buf; + isc_region_t reg; + char *p, txt[DNS_NAME_FORMATSIZE]; + + REQUIRE(VALID_NAME(name)); + REQUIRE(target != NULL && *target == NULL); + + isc_buffer_init(&buf, txt, sizeof(txt)); + result = dns_name_totext(name, false, &buf); + if (result != ISC_R_SUCCESS) { + return (result); + } + + isc_buffer_usedregion(&buf, ®); + p = isc_mem_allocate(mctx, reg.length + 1); + memmove(p, (char *)reg.base, (int)reg.length); + p[reg.length] = '\0'; + + *target = p; + return (ISC_R_SUCCESS); +} + +/* + * dns_name_fromstring() -- convert directly from a string to a name, + * allocating memory as needed + */ +isc_result_t +dns_name_fromstring(dns_name_t *target, const char *src, unsigned int options, + isc_mem_t *mctx) { + return (dns_name_fromstring2(target, src, dns_rootname, options, mctx)); +} + +isc_result_t +dns_name_fromstring2(dns_name_t *target, const char *src, + const dns_name_t *origin, unsigned int options, + isc_mem_t *mctx) { + isc_result_t result; + isc_buffer_t buf; + dns_fixedname_t fn; + dns_name_t *name; + + REQUIRE(src != NULL); + + isc_buffer_constinit(&buf, src, strlen(src)); + isc_buffer_add(&buf, strlen(src)); + if (BINDABLE(target) && target->buffer != NULL) { + name = target; + } else { + name = dns_fixedname_initname(&fn); + } + + result = dns_name_fromtext(name, &buf, origin, options, NULL); + if (result != ISC_R_SUCCESS) { + return (result); + } + + if (name != target) { + result = dns_name_dupwithoffsets(name, mctx, target); + } + return (result); +} + +void +dns_name_copy(const dns_name_t *source, dns_name_t *dest) { + isc_buffer_t *target = NULL; + unsigned char *ndata = NULL; + + REQUIRE(VALID_NAME(source)); + REQUIRE(VALID_NAME(dest)); + REQUIRE(BINDABLE(dest)); + + target = dest->buffer; + + REQUIRE(target != NULL); + REQUIRE(target->length >= source->length); + + isc_buffer_clear(target); + + ndata = (unsigned char *)target->base; + dest->ndata = target->base; + + if (source->length != 0) { + memmove(ndata, source->ndata, source->length); + } + + dest->ndata = ndata; + dest->labels = source->labels; + dest->length = source->length; + if ((source->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) { + dest->attributes = DNS_NAMEATTR_ABSOLUTE; + } else { + dest->attributes = 0; + } + + if (dest->labels > 0 && dest->offsets != NULL) { + if (source->offsets != NULL && source->labels != 0) { + memmove(dest->offsets, source->offsets, source->labels); + } else { + set_offsets(dest, dest->offsets, NULL); + } + } + + isc_buffer_add(target, dest->length); +} + +/* + * Service Discovery Prefixes RFC 6763. + */ +static unsigned char b_dns_sd_udp_data[] = "\001b\007_dns-sd\004_udp"; +static unsigned char b_dns_sd_udp_offsets[] = { 0, 2, 10 }; +static unsigned char db_dns_sd_udp_data[] = "\002db\007_dns-sd\004_udp"; +static unsigned char db_dns_sd_udp_offsets[] = { 0, 3, 11 }; +static unsigned char r_dns_sd_udp_data[] = "\001r\007_dns-sd\004_udp"; +static unsigned char r_dns_sd_udp_offsets[] = { 0, 2, 10 }; +static unsigned char dr_dns_sd_udp_data[] = "\002dr\007_dns-sd\004_udp"; +static unsigned char dr_dns_sd_udp_offsets[] = { 0, 3, 11 }; +static unsigned char lb_dns_sd_udp_data[] = "\002lb\007_dns-sd\004_udp"; +static unsigned char lb_dns_sd_udp_offsets[] = { 0, 3, 11 }; + +static dns_name_t const dns_sd[] = { + DNS_NAME_INITNONABSOLUTE(b_dns_sd_udp_data, b_dns_sd_udp_offsets), + DNS_NAME_INITNONABSOLUTE(db_dns_sd_udp_data, db_dns_sd_udp_offsets), + DNS_NAME_INITNONABSOLUTE(r_dns_sd_udp_data, r_dns_sd_udp_offsets), + DNS_NAME_INITNONABSOLUTE(dr_dns_sd_udp_data, dr_dns_sd_udp_offsets), + DNS_NAME_INITNONABSOLUTE(lb_dns_sd_udp_data, lb_dns_sd_udp_offsets) +}; + +bool +dns_name_isdnssd(const dns_name_t *name) { + size_t i; + dns_name_t prefix; + + if (dns_name_countlabels(name) > 3U) { + dns_name_init(&prefix, NULL); + dns_name_getlabelsequence(name, 0, 3, &prefix); + for (i = 0; i < (sizeof(dns_sd) / sizeof(dns_sd[0])); i++) { + if (dns_name_equal(&prefix, &dns_sd[i])) { + return (true); + } + } + } + + return (false); +} + +static unsigned char inaddr10_offsets[] = { 0, 3, 11, 16 }; +static unsigned char inaddr172_offsets[] = { 0, 3, 7, 15, 20 }; +static unsigned char inaddr192_offsets[] = { 0, 4, 8, 16, 21 }; + +static unsigned char inaddr10[] = "\00210\007IN-ADDR\004ARPA"; + +static unsigned char inaddr16172[] = "\00216\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr17172[] = "\00217\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr18172[] = "\00218\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr19172[] = "\00219\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr20172[] = "\00220\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr21172[] = "\00221\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr22172[] = "\00222\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr23172[] = "\00223\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr24172[] = "\00224\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr25172[] = "\00225\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr26172[] = "\00226\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr27172[] = "\00227\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr28172[] = "\00228\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr29172[] = "\00229\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr30172[] = "\00230\003172\007IN-ADDR\004ARPA"; +static unsigned char inaddr31172[] = "\00231\003172\007IN-ADDR\004ARPA"; + +static unsigned char inaddr168192[] = "\003168\003192\007IN-ADDR\004ARPA"; + +static dns_name_t const rfc1918names[] = { + DNS_NAME_INITABSOLUTE(inaddr10, inaddr10_offsets), + DNS_NAME_INITABSOLUTE(inaddr16172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr17172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr18172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr19172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr20172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr21172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr22172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr23172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr24172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr25172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr26172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr27172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr28172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr29172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr30172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr31172, inaddr172_offsets), + DNS_NAME_INITABSOLUTE(inaddr168192, inaddr192_offsets) +}; + +bool +dns_name_isrfc1918(const dns_name_t *name) { + size_t i; + + for (i = 0; i < (sizeof(rfc1918names) / sizeof(*rfc1918names)); i++) { + if (dns_name_issubdomain(name, &rfc1918names[i])) { + return (true); + } + } + return (false); +} + +static unsigned char ulaoffsets[] = { 0, 2, 4, 8, 13 }; +static unsigned char ip6fc[] = "\001c\001f\003ip6\004ARPA"; +static unsigned char ip6fd[] = "\001d\001f\003ip6\004ARPA"; + +static dns_name_t const ulanames[] = { DNS_NAME_INITABSOLUTE(ip6fc, ulaoffsets), + DNS_NAME_INITABSOLUTE(ip6fd, + ulaoffsets) }; + +bool +dns_name_isula(const dns_name_t *name) { + size_t i; + + for (i = 0; i < (sizeof(ulanames) / sizeof(*ulanames)); i++) { + if (dns_name_issubdomain(name, &ulanames[i])) { + return (true); + } + } + return (false); +} + +/* + * Use a simple table as we don't want all the locale stuff + * associated with ishexdigit(). + */ +const char ishex[256] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, + 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; + +bool +dns_name_istat(const dns_name_t *name) { + unsigned char len; + const unsigned char *ndata; + + REQUIRE(VALID_NAME(name)); + + if (name->labels < 1) { + return (false); + } + + ndata = name->ndata; + len = ndata[0]; + INSIST(len <= name->length); + ndata++; + + /* + * Is there at least one trust anchor reported and is the + * label length consistent with a trust-anchor-telemetry label. + */ + if ((len < 8) || (len - 3) % 5 != 0) { + return (false); + } + + if (ndata[0] != '_' || maptolower[ndata[1]] != 't' || + maptolower[ndata[2]] != 'a') + { + return (false); + } + ndata += 3; + len -= 3; + + while (len > 0) { + INSIST(len >= 5); + if (ndata[0] != '-' || !ishex[ndata[1]] || !ishex[ndata[2]] || + !ishex[ndata[3]] || !ishex[ndata[4]]) + { + return (false); + } + ndata += 5; + len -= 5; + } + return (true); +} |