/* $NetBSD: name.c,v 1.11.2.2 2024/02/25 15:46:50 martin Exp $ */ /* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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); INSIST(name->ht == NULL); } 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, ""); } } /* * 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); }