name.c revision 190fbe9738bd0c1b9b13732bb8bd56b2b7c71640
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson/*
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * Copyright (C) 1998-2000 Internet Software Consortium.
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson *
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * Permission to use, copy, modify, and distribute this software for any
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * purpose with or without fee is hereby granted, provided that the above
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * copyright notice and this permission notice appear in all copies.
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson *
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
68a8db1efb0cd13e0e3d59362ab9db1a4a8bc496Andreas Gustafsson */
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson/* $Id: name.c,v 1.105 2000/10/14 04:31:31 tale Exp $ */
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <config.h>
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <ctype.h>
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <isc/buffer.h>
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <isc/mem.h>
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <isc/print.h>
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <isc/string.h>
4848fe4ad2c0ba6e2e69e4a2617727f8556d79a0Andreas Gustafsson#include <isc/util.h>
#include <dns/result.h>
#include <dns/name.h>
#include <dns/compress.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_bitstring,
ft_binary,
ft_octal,
ft_hex,
ft_dottedquad,
ft_dqdecimal,
ft_maybeslash,
ft_finishbitstring,
ft_bitlength,
ft_eatdot,
ft_at
} ft_state;
typedef enum {
fw_start = 0,
fw_ordinary,
fw_copy,
fw_bitstring,
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 char hexdigits[16] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
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) \
if (name->offsets != NULL) \
var = name->offsets; \
else \
var = default;
#define SETUP_OFFSETS(name, var, default) \
if (name->offsets != NULL) \
var = name->offsets; \
else { \
var = default; \
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)
/*
* This silliness is to avoid warnings about the const attribute of a string
* being discarded, as can happen (depending on the compiler and flags)
* when name.ndata or name.offsets is assigned to via a string literal.
* Unfortunately, gcc -Wwrite-strings produces incorrect warnings for
* assigning a const string to the ndata or offsets members in
* "const struct dns_name root", which (at least according to the ANSI
* Draft dated August 3, 1998) should have the effect of declaring all
* members of the struct as const.
*/
struct dns_constname {
dns_name_t name;
unsigned char const_ndata[2];
unsigned char const_offsets[1];
};
static struct dns_constname root = {
{
DNS_NAME_MAGIC,
root.const_ndata, 1, 1,
DNS_NAMEATTR_READONLY | DNS_NAMEATTR_ABSOLUTE,
root.const_offsets, NULL,
{(void *)-1, (void *)-1},
{NULL, NULL}
},
{ '\0', '\0' }, /* const_ndata */
{ '\0' } /* const_offsets */
};
/* XXXDCL make const? */
dns_name_t *dns_rootname = &root.name;
static struct dns_constname wild = {
{
DNS_NAME_MAGIC,
wild.const_ndata, 2, 1,
DNS_NAMEATTR_READONLY,
wild.const_offsets, NULL,
{(void *)-1, (void *)-1},
{NULL, NULL}
},
{ '\001', '*' }, /* const_ndata */
{ '\0' } /* const_offsets */
};
/* XXXDCL make const? */
dns_name_t *dns_wildcardname = &wild.name;
static void
set_offsets(const dns_name_t *name, unsigned char *offsets,
dns_name_t *set_name);
static void
compact(dns_name_t *name, unsigned char *offsets);
/*
* Yes, get_bit and set_bit are lame. We define them here so they can
* be inlined by smart compilers.
*/
static inline unsigned int
get_bit(unsigned char *array, unsigned int idx) {
unsigned int byte, shift;
byte = array[idx / 8];
shift = 7 - (idx % 8);
return ((byte >> shift) & 0x01);
}
static inline void
set_bit(unsigned char *array, unsigned int idx, unsigned int bit) {
unsigned int shift, mask;
shift = 7 - (idx % 8);
mask = 1 << shift;
if (bit != 0)
array[idx / 8] |= mask;
else
array[idx / 8] &= (~mask & 0xFF);
}
dns_labeltype_t
dns_label_type(dns_label_t *label) {
/*
* Get the type of 'label'.
*/
REQUIRE(label != NULL);
REQUIRE(label->length > 0);
REQUIRE(label->base[0] <= 63 ||
label->base[0] == DNS_LABELTYPE_BITSTRING);
if (label->base[0] <= 63)
return (dns_labeltype_ordinary);
else
return (dns_labeltype_bitstring);
}
unsigned int
dns_label_countbits(dns_label_t *label) {
unsigned int count;
/*
* The number of bits in a bitstring label.
*/
REQUIRE(label != NULL);
REQUIRE(label->length > 2);
REQUIRE(label->base[0] == DNS_LABELTYPE_BITSTRING);
count = label->base[1];
if (count == 0)
count = 256;
return (count);
}
dns_bitlabel_t
dns_label_getbit(dns_label_t *label, unsigned int n) {
unsigned int count, bit;
/*
* The 'n'th most significant bit of 'label'.
*
* Notes:
* Numbering starts at 0.
*/
REQUIRE(label != NULL);
REQUIRE(label->length > 2);
REQUIRE(label->base[0] == DNS_LABELTYPE_BITSTRING);
count = label->base[1];
if (count == 0)
count = 256;
REQUIRE(n < count);
bit = get_bit(&label->base[2], n);
if (bit == 0)
return (dns_bitlabel_0);
return (dns_bitlabel_1);
}
void
dns_name_init(dns_name_t *name, unsigned char *offsets) {
/*
* Initialize 'name'.
*/
name->magic = DNS_NAME_MAGIC;
name->ndata = NULL;
name->length = 0;
name->labels = 0;
name->attributes = 0;
name->offsets = offsets;
name->buffer = NULL;
ISC_LINK_INIT(name, link);
ISC_LIST_INIT(name->list);
}
void
dns_name_reset(dns_name_t *name) {
REQUIRE(VALID_NAME(name));
REQUIRE(BINDABLE(name));
MAKE_EMPTY(name);
if (name->buffer != NULL)
isc_buffer_clear(name->buffer);
}
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);
}
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;
}
isc_boolean_t
dns_name_hasbuffer(const dns_name_t *name) {
/*
* Does 'name' have a dedicated buffer?
*/
REQUIRE(VALID_NAME(name));
if (name->buffer != NULL)
return (ISC_TRUE);
return (ISC_FALSE);
}
isc_boolean_t
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 (ISC_TRUE);
return (ISC_FALSE);
}
isc_boolean_t
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 (ISC_TRUE);
}
return (ISC_FALSE);
}
isc_boolean_t
dns_name_requiresedns(const dns_name_t *name) {
unsigned int count, nrem;
unsigned char *ndata;
isc_boolean_t requiresedns = ISC_FALSE;
/*
* Does 'name' require EDNS for transmission?
*/
REQUIRE(VALID_NAME(name));
REQUIRE(name->labels > 0);
ndata = name->ndata;
nrem = name->length;
while (nrem > 0) {
count = *ndata++;
nrem--;
if (count == 0)
break;
if (count > 63) {
INSIST(count == DNS_LABELTYPE_BITSTRING);
requiresedns = ISC_TRUE;
break;
}
INSIST(nrem >= count);
nrem -= count;
ndata += count;
}
return (requiresedns);
}
unsigned int
dns_name_hash(dns_name_t *name, isc_boolean_t case_sensitive) {
unsigned int length;
const unsigned char *s;
unsigned int h = 0;
unsigned char c;
/*
* Provide a hash value for 'name'.
*/
REQUIRE(VALID_NAME(name));
if (name->labels == 0)
return (0);
length = name->length;
if (length > 16)
length = 16;
/*
* This hash function is similar to the one Ousterhout
* uses in Tcl.
*/
s = name->ndata;
if (case_sensitive) {
while (length > 0) {
h += ( h << 3 ) + *s;
s++;
length--;
}
} else {
while (length > 0) {
c = maptolower[*s];
h += ( h << 3 ) + c;
s++;
length--;
}
}
return (h);
}
dns_namereln_t
dns_name_fullcompare(const dns_name_t *name1, const dns_name_t *name2,
int *orderp,
unsigned int *nlabelsp, unsigned int *nbitsp)
{
unsigned int l1, l2, l, count1, count2, count;
unsigned int b1, b2, n, nlabels, nbits;
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);
REQUIRE(nbitsp != NULL);
/*
* Either name1 is absolute and name2 is absolute, or neither is.
*/
REQUIRE((name1->attributes & DNS_NAMEATTR_ABSOLUTE) ==
(name2->attributes & DNS_NAMEATTR_ABSOLUTE));
SETUP_OFFSETS(name1, offsets1, odata1);
SETUP_OFFSETS(name2, offsets2, odata2);
nlabels = 0;
nbits = 0;
l1 = name1->labels;
l2 = name2->labels;
ldiff = (int)l1 - (int)l2;
if (ldiff < 0)
l = l1;
else
l = l2;
while (l > 0) {
l--;
l1--;
l2--;
label1 = &name1->ndata[offsets1[l1]];
label2 = &name2->ndata[offsets2[l2]];
count1 = *label1++;
count2 = *label2++;
if (count1 <= 63 && count2 <= 63) {
cdiff = (int)count1 - (int)count2;
if (cdiff < 0)
count = count1;
else
count = count2;
while (count > 0) {
chdiff = (int)maptolower[*label1] -
(int)maptolower[*label2];
if (chdiff != 0) {
*orderp = chdiff;
goto done;
}
count--;
label1++;
label2++;
}
if (cdiff != 0) {
*orderp = cdiff;
goto done;
}
nlabels++;
} else if (count1 == DNS_LABELTYPE_BITSTRING && count2 <= 63) {
if (count2 == 0)
*orderp = 1;
else
*orderp = -1;
goto done;
} else if (count2 == DNS_LABELTYPE_BITSTRING && count1 <= 63) {
if (count1 == 0)
*orderp = -1;
else
*orderp = 1;
goto done;
} else {
INSIST(count1 == DNS_LABELTYPE_BITSTRING &&
count2 == DNS_LABELTYPE_BITSTRING);
count1 = *label1++;
if (count1 == 0)
count1 = 256;
count2 = *label2++;
if (count2 == 0)
count2 = 256;
if (count1 < count2) {
cdiff = -1;
count = count1;
} else {
count = count2;
if (count1 > count2)
cdiff = 1;
else
cdiff = 0;
}
/* Yes, this loop is really slow! */
for (n = 0; n < count; n++) {
b1 = get_bit(label1, n);
b2 = get_bit(label2, n);
if (b1 < b2) {
*orderp = -1;
goto done;
} else if (b1 > b2) {
*orderp = 1;
goto done;
}
if (nbits == 0)
nlabels++;
nbits++;
}
if (cdiff != 0) {
/*
* If we're here, then we have two bitstrings
* of differing length.
*
* If the name with the shorter bitstring
* has any labels, then it must be greater
* than the longer bitstring. This is a bit
* counterintuitive. If the name with the
* shorter bitstring has any more labels, then
* the next label must be an ordinary label.
* It can't be a bitstring label because if it
* were, then there would be room for it in
* the current bitstring label (since all
* bitstrings are canonicalized). Since
* there's at least one more bit in the
* name with the longer bitstring, and since
* a bitlabel sorts before any ordinary label,
* the name with the longer bitstring must
* be lexically before the one with the shorter
* bitstring.
*
* On the other hand, if there are no more
* labels in the name with the shorter
* bitstring, then that name contains the
* other name.
*/
namereln = dns_namereln_commonancestor;
if (cdiff < 0) {
if (l1 > 0)
*orderp = 1;
else {
*orderp = -1;
namereln =
dns_namereln_contains;
}
} else {
if (l2 > 0)
*orderp = -1;
else {
*orderp = 1;
namereln =
dns_namereln_subdomain;
}
}
goto done;
}
nbits = 0;
}
}
*orderp = ldiff;
if (ldiff < 0)
namereln = dns_namereln_contains;
else if (ldiff > 0)
namereln = dns_namereln_subdomain;
else
namereln = dns_namereln_equal;
done:
*nlabelsp = nlabels;
*nbitsp = nbits;
if (nlabels > 0 && namereln == dns_namereln_none)
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, nbits;
/*
* 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, &nbits);
return (order);
}
isc_boolean_t
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->length != name2->length)
return (ISC_FALSE);
l = name1->labels;
if (l != name2->labels)
return (ISC_FALSE);
label1 = name1->ndata;
label2 = name2->ndata;
while (l > 0) {
l--;
count = *label1++;
if (count != *label2++)
return (ISC_FALSE);
if (count <= 63) {
while (count > 0) {
count--;
c = maptolower[*label1++];
if (c != maptolower[*label2++])
return (ISC_FALSE);
}
} else {
INSIST(count == DNS_LABELTYPE_BITSTRING);
count = *label1++;
if (count != *label2++)
return (ISC_FALSE);
if (count == 0)
count = 256;
/*
* Number of bytes.
*/
count = (count + 7) / 8;
while (count > 0) {
count--;
c = *label1++;
if (c != *label2++)
return (ISC_FALSE);
}
}
}
return (ISC_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++;
if (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);
}
} else if (count1 == DNS_LABELTYPE_BITSTRING && count2 <= 63) {
return (1);
} else if (count2 == DNS_LABELTYPE_BITSTRING && count1 <= 63) {
return (-1);
} else {
INSIST(count1 == DNS_LABELTYPE_BITSTRING &&
count2 == DNS_LABELTYPE_BITSTRING);
count2 = *label2++;
count1 = *label1++;
if (count1 != count2)
return ((count1 < count2) ? -1 : 1);
if (count1 == 0)
count1 = 256;
if (count2 == 0)
count2 = 256;
/* number of bytes */
count = (count1 + 7) / 8;
while (count > 0) {
count--;
c1 = *label1++;
c2 = *label2++;
if (c1 != c2)
return ((c1 < c2) ? -1 : 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);
}
isc_boolean_t
dns_name_issubdomain(const dns_name_t *name1, const dns_name_t *name2) {
int order;
unsigned int nlabels, nbits;
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,
&nbits);
if (namereln == dns_namereln_subdomain ||
namereln == dns_namereln_equal)
return (ISC_TRUE);
return (ISC_FALSE);
}
isc_boolean_t
dns_name_matcheswildcard(const dns_name_t *name, const dns_name_t *wname) {
int order;
unsigned int nlabels, nbits, 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, &nbits) ==
dns_namereln_subdomain)
return (ISC_TRUE);
return (ISC_FALSE);
}
unsigned int
dns_name_depth(const dns_name_t *name) {
unsigned int depth, count, nrem, n;
unsigned char *ndata;
/*
* The depth of 'name'.
*/
REQUIRE(VALID_NAME(name));
if (name->labels == 0)
return (0);
depth = 0;
ndata = name->ndata;
nrem = name->length;
while (nrem > 0) {
count = *ndata++;
nrem--;
if (count > 63) {
INSIST(count == DNS_LABELTYPE_BITSTRING);
INSIST(nrem != 0);
n = *ndata++;
nrem--;
if (n == 0)
n = 256;
depth += n;
count = n / 8;
if (n % 8 != 0)
count++;
} else {
depth++;
if (count == 0)
break;
}
INSIST(nrem >= count);
nrem -= count;
ndata += count;
}
return (depth);
}
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 *offsets;
dns_offsets_t odata;
unsigned int firstoffset, endoffset;
/*
* 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(first + n <= source->labels);
REQUIRE(BINDABLE(target));
SETUP_OFFSETS(source, offsets, odata);
if (first == source->labels)
firstoffset = source->length;
else
firstoffset = offsets[first];
if (first + n == source->labels)
endoffset = source->length;
else
endoffset = offsets[first + n];
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(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)
memcpy(target->offsets, source->offsets,
source->labels);
else
set_offsets(target, target->offsets, NULL);
}
}
void
dns_name_fromregion(dns_name_t *name, 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;
memcpy(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(dns_name_t *name, isc_region_t *r) {
/*
* Make 'r' refer to 'name'.
*/
REQUIRE(VALID_NAME(name));
REQUIRE(r != NULL);
r->base = name->ndata;
r->length = name->length;
}
isc_result_t
dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
dns_name_t *origin, isc_boolean_t downcase,
isc_buffer_t *target)
{
unsigned char *ndata, *label;
char *tdata;
char c;
ft_state state, kind;
unsigned int value, count, tbcount, bitlength, maxlength;
unsigned int n1, n2, vlen, tlen, nrem, nused, digits, labels, tused;
isc_boolean_t done, saw_bitstring;
unsigned char dqchars[4];
unsigned char *offsets;
dns_offsets_t odata;
/*
* 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(isc_buffer_current(source) < isc_buffer_used(source));
REQUIRE((target != NULL && ISC_BUFFER_VALID(target)) ||
(target == NULL && name->buffer != NULL));
if (target == NULL && name->buffer != NULL) {
target = name->buffer;
isc_buffer_clear(target);
}
REQUIRE(BINDABLE(name));
INIT_OFFSETS(name, offsets, odata);
offsets[0] = 0;
/*
* Initialize things to make the compiler happy; they're not required.
*/
n1 = 0;
n2 = 0;
vlen = 0;
label = NULL;
digits = 0;
value = 0;
count = 0;
tbcount = 0;
bitlength = 0;
maxlength = 0;
kind = ft_init;
/*
* 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 = ISC_FALSE;
saw_bitstring = ISC_FALSE;
state = ft_init;
while (nrem > 0 && tlen > 0 && !done) {
c = *tdata++;
tlen--;
tused++;
no_read:
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 = ISC_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;
}
kind = ft_ordinary;
state = ft_ordinary;
/* 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 = ISC_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[(int)c];
*ndata++ = c;
nrem--;
nused++;
}
break;
case ft_initialescape:
if (c == '[') {
saw_bitstring = ISC_TRUE;
kind = ft_bitstring;
state = ft_bitstring;
*label = DNS_LABELTYPE_BITSTRING;
label = ndata;
ndata++;
nrem--;
nused++;
break;
}
kind = ft_ordinary;
state = ft_escape;
/* FALLTHROUGH */
case ft_escape:
if (!isdigit(c & 0xff)) {
if (count >= 63)
return (DNS_R_LABELTOOLONG);
count++;
CONVERTTOASCII(c);
if (downcase)
c = maptolower[(int)c];
*ndata++ = c;
nrem--;
nused++;
state = ft_ordinary;
break;
}
digits = 0;
value = 0;
state = ft_escdecimal;
/* FALLTHROUGH */
case ft_escdecimal:
if (!isdigit(c & 0xff))
return (DNS_R_BADESCAPE);
value *= 10;
value += digitvalue[(int)c];
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;
case ft_bitstring:
/* count is zero */
tbcount = 0;
value = 0;
if (c == 'b') {
vlen = 8;
maxlength = 256;
kind = ft_binary;
state = ft_binary;
} else if (c == 'o') {
vlen = 8;
maxlength = 256;
kind = ft_octal;
state = ft_octal;
} else if (c == 'x') {
vlen = 8;
maxlength = 256;
kind = ft_hex;
state = ft_hex;
} else if (isdigit(c & 0xff)) {
vlen = 32;
maxlength = 32;
n1 = 0;
n2 = 0;
digits = 0;
kind = ft_dottedquad;
state = ft_dqdecimal;
goto no_read;
} else
return (DNS_R_BADBITSTRING);
break;
case ft_binary:
if (c != '0' && c != '1') {
state = ft_maybeslash;
goto no_read;
}
value <<= 1;
if (c == '1')
value |= 1;
count++;
tbcount++;
if (tbcount > 256)
return (DNS_R_BITSTRINGTOOLONG);
if (count == 8) {
*ndata++ = value;
nrem--;
nused++;
count = 0;
}
break;
case ft_octal:
if (!isdigit(c & 0xff) || c == '9' || c == '8') {
state = ft_maybeslash;
goto no_read;
}
value <<= 3;
value += digitvalue[(int)c];
count += 3;
tbcount += 3;
/*
* The total bit count is tested against 258 instead
* of 256 because of the possibility that the bitstring
* label is exactly 256 bits long; on the last octal
* digit (which must be 4) tbcount is incremented
* from 255 to 258. This case is adequately handled
* later.
*/
if (tbcount > 258)
return (DNS_R_BITSTRINGTOOLONG);
if (count == 8) {
*ndata++ = value;
nrem--;
nused++;
count = 0;
} else if (count == 9) {
*ndata++ = (value >> 1);
nrem--;
nused++;
value &= 1;
count = 1;
} else if (count == 10) {
*ndata++ = (value >> 2);
nrem--;
nused++;
value &= 3;
count = 2;
}
break;
case ft_hex:
if (!isxdigit(c & 0xff)) {
state = ft_maybeslash;
goto no_read;
}
value <<= 4;
value += digitvalue[(int)c];
count += 4;
tbcount += 4;
if (tbcount > 256)
return (DNS_R_BITSTRINGTOOLONG);
if (count == 8) {
*ndata++ = value;
nrem--;
nused++;
count = 0;
}
break;
case ft_dottedquad:
if (c != '.' && n1 < 3)
return (DNS_R_BADDOTTEDQUAD);
dqchars[n1] = value;
n2 *= 256;
n2 += value;
n1++;
if (n1 == 4) {
tbcount = 32;
value = n2;
state = ft_maybeslash;
goto no_read;
}
value = 0;
digits = 0;
state = ft_dqdecimal;
break;
case ft_dqdecimal:
if (!isdigit(c & 0xff)) {
if (digits == 0 || value > 255)
return (DNS_R_BADDOTTEDQUAD);
state = ft_dottedquad;
goto no_read;
}
digits++;
if (digits > 3)
return (DNS_R_BADDOTTEDQUAD);
value *= 10;
value += digitvalue[(int)c];
break;
case ft_maybeslash:
bitlength = 0;
if (c == '/') {
state = ft_bitlength;
break;
}
/* FALLTHROUGH */
case ft_finishbitstring:
if (c == ']') {
if (tbcount == 0)
return (DNS_R_BADBITSTRING);
if (count > 0) {
n1 = count % 8;
if (n1 != 0)
value <<= (8 - n1);
}
if (bitlength != 0) {
if (bitlength > tbcount)
return (DNS_R_BADBITSTRING);
if (kind == ft_binary &&
bitlength != tbcount) {
return (DNS_R_BADBITSTRING);
} else if (kind == ft_octal) {
/*
* Figure out correct number
* of octal digits for the
* bitlength, and compare to
* what was given.
*/
n1 = bitlength / 3;
if (bitlength % 3 != 0)
n1++;
n2 = tbcount / 3;
/* tbcount % 3 == 0 */
if (n1 != n2)
return (DNS_R_BADBITSTRING);
/*
* Check that no bits extend
* past the end of the last
* byte that is included in
* the bitlength. Example:
* \[o036/8] == \[b00001111],
* which fits into just one
* byte, but the three octal
* digits actually specified
* two bytes worth of data,
* 9 bits, before the bitlength
* limited it back to one byte.
*
* n1 is the number of bytes
* necessary for the bitlength.
* n2 is the number of bytes
* encompassed by the octal
* digits. If they are not
* equal, then "value" holds
* the excess bits, which
* must be zero. If the bits
* are zero, then "count" is
* zero'ed to prevent the
* addition of another byte
* below.
*/
n1 = bitlength - 1 / 8;
n2 = tbcount - 1 / 8;
if (n1 != n2) {
if (value != 0)
return
(DNS_R_BADBITSTRING);
else
count = 0;
}
} else if (kind == ft_hex) {
/*
* Figure out correct number
* of hex digits for the
* bitlength, and compare to
* what was given.
*/
n1 = bitlength / 4;
if (bitlength % 4 != 0)
n1++;
n2 = tbcount / 4;
/* tbcount % 4 == 0 */
if (n1 != n2)
return (DNS_R_BADBITSTRING);
}
n1 = bitlength % vlen;
if (n1 != 0) {
/*
* Are the pad bits in the
* last 'vlen' bits zero?
*/
if ((value &
~((~0) << (vlen-n1))) != 0)
return (DNS_R_BADBITSTRING);
}
} else if (kind == ft_dottedquad)
bitlength = 32;
else if (tbcount > 256)
/*
* This can happen when an octal
* bitstring label of 86 octal digits
* is specified; tbcount will be 258.
* This is not trapped above because
* the bitstring label might be limited
* by a "/256" modifier.
*/
return (DNS_R_BADBITSTRING);
else
bitlength = tbcount;
if (count > 0) {
*ndata++ = value;
nrem--;
nused++;
}
if (kind == ft_dottedquad) {
n1 = bitlength / 8;
if (bitlength % 8 != 0)
n1++;
if (nrem < n1)
return (ISC_R_NOSPACE);
for (n2 = 0; n2 < n1; n2++) {
*ndata++ = dqchars[n2];
nrem--;
nused++;
}
}
if (bitlength == 256)
*label = 0;
else
*label = bitlength;
labels++;
INSIST(labels <= 127);
offsets[labels] = nused;
} else
return (DNS_R_BADBITSTRING);
state = ft_eatdot;
break;
case ft_bitlength:
if (!isdigit(c & 0xff)) {
if (bitlength == 0)
return (DNS_R_BADBITSTRING);
state = ft_finishbitstring;
goto no_read;
}
bitlength *= 10;
bitlength += digitvalue[(int)c];
if (bitlength > maxlength)
return (DNS_R_BADBITSTRING);
break;
case ft_eatdot:
if (c != '.')
return (DNS_R_BADBITSTRING);
if (tlen == 0) {
labels++;
*ndata++ = 0;
nrem--;
nused++;
done = ISC_TRUE;
}
state = ft_start;
break;
default:
FATAL_ERROR(__FILE__, __LINE__,
"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_eatdot &&
state != ft_at)
return (ISC_R_UNEXPECTEDEND);
if (state == ft_ordinary) {
INSIST(count != 0);
*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;
while (n1 > 0) {
n2 = *label++;
if (n2 <= 63) {
*ndata++ = n2;
n1 -= n2 + 1;
nused += n2 + 1;
while (n2 > 0) {
c = *label++;
if (downcase)
c = maptolower[(int)c];
*ndata++ = c;
n2--;
}
} else {
INSIST(n2 == DNS_LABELTYPE_BITSTRING);
*ndata++ = n2;
bitlength = *label++;
*ndata++ = bitlength;
if (bitlength == 0)
bitlength = 256;
n2 = bitlength / 8;
if (bitlength % 8 != 0)
n2++;
n1 -= n2 + 2;
nused += n2 + 2;
while (n2 > 0) {
*ndata++ = *label++;
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;
if (saw_bitstring)
compact(name, offsets);
isc_buffer_forward(source, tused);
isc_buffer_add(target, name->length);
return (ISC_R_SUCCESS);
}
isc_result_t
dns_name_totext(dns_name_t *name, isc_boolean_t 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 bytes, nibbles;
size_t i, len;
unsigned int labels;
isc_boolean_t saw_root = ISC_FALSE;
char num[4];
/*
* This function assumes the name is in proper uncompressed
* wire format.
*/
REQUIRE(VALID_NAME(name));
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 (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 = ISC_TRUE;
omit_final_dot = ISC_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 = ISC_TRUE;
omit_final_dot = ISC_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 = ISC_TRUE;
break;
}
if (count < 64) {
INSIST(nlen >= count);
while (count > 0) {
c = *ndata;
switch (c) {
case 0x22: /* '"' */
case 0x2E: /* '.' */
case 0x3B: /* ';' */
case 0x5C: /* '\\' */
/* Special modifiers in zone files. */
case 0x40: /* '@' */
case 0x24: /* '$' */
if (trem < 2)
return (ISC_R_NOSPACE);
*tdata++ = '\\';
CONVERTFROMASCII(c);
*tdata++ = c;
ndata++;
trem -= 2;
nlen--;
break;
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);
sprintf(tdata, "\\%03u",
c);
tdata += 4;
trem -= 4;
ndata++;
nlen--;
}
}
count--;
}
} else if (count == DNS_LABELTYPE_BITSTRING) {
if (trem < 3)
return (ISC_R_NOSPACE);
*tdata++ = '\\';
*tdata++ = '[';
*tdata++ = 'x';
trem -= 3;
INSIST(nlen > 0);
count = *ndata++;
if (count == 0)
count = 256;
nlen--;
len = sprintf(num, "%u", count); /* XXX */
INSIST(len <= 4);
bytes = count / 8;
if (count % 8 != 0)
bytes++;
INSIST(nlen >= bytes);
nibbles = count / 4;
if (count % 4 != 0)
nibbles++;
if (trem < nibbles)
return (ISC_R_NOSPACE);
trem -= nibbles;
nlen -= bytes;
while (nibbles > 0) {
c = *ndata++;
*tdata++ = hexdigits[(c >> 4)];
nibbles--;
if (nibbles != 0) {
*tdata++ = hexdigits[c & 0xf];
i++;
nibbles--;
}
}
if (trem < 2 + len)
return (ISC_R_NOSPACE);
*tdata++ = '/';
for (i = 0; i < len; i++)
*tdata++ = num[i];
*tdata++ = ']';
trem -= 2 + len;
} else {
FATAL_ERROR(__FILE__, __LINE__,
"Unexpected label type %02x", count);
/* NOTREACHED */
}
/*
* 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++;
isc_buffer_add(target, tlen - trem);
return (ISC_R_SUCCESS);
}
isc_result_t
dns_name_downcase(dns_name_t *source, dns_name_t *name, isc_buffer_t *target) {
unsigned char *sndata, *ndata;
unsigned int nlen, count, bytes, 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));
if (target == NULL && name->buffer != 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 if (count == DNS_LABELTYPE_BITSTRING) {
INSIST(nlen > 0);
count = *sndata++;
*ndata++ = count;
if (count == 0)
count = 256;
nlen--;
bytes = count / 8;
if (count % 8 != 0)
bytes++;
INSIST(nlen >= bytes);
nlen -= bytes;
while (bytes > 0) {
*ndata++ = *sndata++;
bytes--;
}
} else {
FATAL_ERROR(__FILE__, __LINE__,
"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, n;
unsigned char *ndata;
isc_boolean_t absolute;
ndata = name->ndata;
length = name->length;
offset = 0;
nlabels = 0;
absolute = ISC_FALSE;
while (offset != length) {
INSIST(nlabels < 128);
offsets[nlabels++] = offset;
count = *ndata++;
offset++;
if (count <= 63) {
offset += count;
ndata += count;
INSIST(offset <= length);
if (count == 0) {
absolute = ISC_TRUE;
break;
}
} else {
INSIST(count == DNS_LABELTYPE_BITSTRING);
n = *ndata++;
offset++;
if (n == 0)
n = 256;
count = n / 8;
if (n % 8 != 0)
count++;
offset += count;
ndata += count;
INSIST(offset <= length);
}
}
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);
}
static void
compact(dns_name_t *name, unsigned char *offsets) {
unsigned char *head, *curr, *last;
unsigned int count, n, bit;
unsigned int headbits, currbits, tailbits, newbits;
unsigned int headrem, newrem;
unsigned int headindex, currindex, tailindex, newindex;
unsigned char tail[32];
/*
* The caller MUST ensure that all bitstrings are correctly formatted
* and that the offsets table is valid.
*/
again:
memset(tail, 0, sizeof tail);
INSIST(name->labels != 0);
n = name->labels - 1;
while (n > 0) {
head = &name->ndata[offsets[n]];
if (head[0] == DNS_LABELTYPE_BITSTRING && head[1] != 0) {
if (n != 0) {
n--;
curr = &name->ndata[offsets[n]];
if (curr[0] != DNS_LABELTYPE_BITSTRING)
continue;
/*
* We have consecutive bitstrings labels, and
* the more significant label ('head') has
* space.
*/
currbits = curr[1];
if (currbits == 0)
currbits = 256;
currindex = 0;
headbits = head[1];
if (headbits == 0)
headbits = 256;
headindex = headbits;
count = 256 - headbits;
if (count > currbits)
count = currbits;
headrem = headbits % 8;
if (headrem != 0)
headrem = 8 - headrem;
if (headrem != 0) {
if (headrem > count)
headrem = count;
do {
bit = get_bit(&curr[2],
currindex);
set_bit(&head[2], headindex,
bit);
currindex++;
headindex++;
headbits++;
count--;
headrem--;
} while (headrem != 0);
}
tailindex = 0;
tailbits = 0;
while (count > 0) {
bit = get_bit(&curr[2], currindex);
set_bit(tail, tailindex, bit);
currindex++;
tailindex++;
tailbits++;
count--;
}
newbits = 0;
newindex = 0;
if (currindex < currbits) {
while (currindex < currbits) {
bit = get_bit(&curr[2],
currindex);
set_bit(&curr[2], newindex,
bit);
currindex++;
newindex++;
newbits++;
}
INSIST(newbits < 256);
curr[1] = newbits;
count = newbits / 8;
newrem = newbits % 8;
/* Zero remaining pad bits, if any. */
if (newrem != 0) {
count++;
newrem = 8 - newrem;
while (newrem > 0) {
set_bit(&curr[2],
newindex,
0);
newrem--;
newindex++;
}
}
curr += count + 2;
} else {
/* We got rid of curr. */
name->labels--;
}
/* copy head, then tail, then rest to curr. */
count = headbits + tailbits;
INSIST(count <= 256);
curr[0] = DNS_LABELTYPE_BITSTRING;
if (count == 256)
curr[1] = 0;
else
curr[1] = count;
curr += 2;
head += 2;
count = headbits / 8;
if (headbits % 8 != 0)
count++;
while (count > 0) {
*curr++ = *head++;
count--;
}
count = tailbits / 8;
if (tailbits % 8 != 0)
count++;
last = tail;
while (count > 0) {
*curr++ = *last++;
count--;
}
last = name->ndata + name->length;
while (head != last)
*curr++ = *head++;
name->length = (curr - name->ndata);
/*
* The offsets table may now be invalid.
*/
set_offsets(name, offsets, NULL);
goto again;
}
}
n--;
}
}
isc_result_t
dns_name_fromwire(dns_name_t *name, isc_buffer_t *source,
dns_decompress_t *dctx, isc_boolean_t downcase,
isc_buffer_t *target)
{
unsigned char *cdata, *ndata;
unsigned int cused; /* Bytes of compressed name data used */
unsigned int hops, nused, labels, n, nmax;
unsigned int current, new_current, biggest_pointer;
isc_boolean_t saw_bitstring, done;
fw_state state = fw_start;
unsigned int c;
unsigned char *offsets;
dns_offsets_t odata;
/*
* Copy the possibly-compressed name at source into target,
* decompressing it.
*/
REQUIRE(VALID_NAME(name));
if (target == NULL && name->buffer != NULL) {
target = name->buffer;
isc_buffer_clear(target);
}
REQUIRE(dctx != NULL);
REQUIRE(BINDABLE(name));
INIT_OFFSETS(name, offsets, odata);
/*
* Make 'name' empty in case of failure.
*/
MAKE_EMPTY(name);
/*
* Initialize things to make the compiler happy; they're not required.
*/
n = 0;
new_current = 0;
/*
* Set up.
*/
labels = 0;
hops = 0;
saw_bitstring = ISC_FALSE;
done = ISC_FALSE;
ndata = isc_buffer_used(target);
nused = 0;
/*
* Find the maximum number of uncompressed target name
* bytes we are willing to generate. This is the smaller
* of the available target buffer length and the
* maximum legal domain name length (255).
*/
nmax = isc_buffer_availablelength(target);
if (nmax > DNS_NAME_MAXWIRE)
nmax = DNS_NAME_MAXWIRE;
cdata = isc_buffer_current(source);
cused = 0;
current = source->current;
biggest_pointer = current;
/*
* Note: The following code is not optimized for speed, but
* rather for correctness. Speed will be addressed in the future.
*/
while (current < source->active && !done) {
c = *cdata++;
current++;
if (hops == 0)
cused++;
switch (state) {
case fw_start:
if (c < 64) {
labels++;
if (nused + c + 1 > nmax)
goto full;
nused += c + 1;
*ndata++ = c;
if (c == 0)
done = ISC_TRUE;
n = c;
state = fw_ordinary;
} else if (c >= 128 && c < 192) {
/*
* 14 bit local compression pointer.
* Local compression is no longer an
* IETF draft.
*/
return (DNS_R_BADLABELTYPE);
} else if (c >= 192) {
/*
* Ordinary 14-bit pointer.
*/
if ((dctx->allowed & DNS_COMPRESS_GLOBAL14) ==
0)
return (DNS_R_DISALLOWED);
new_current = c & 0x3F;
n = 1;
state = fw_newcurrent;
} else if (c == DNS_LABELTYPE_BITSTRING) {
labels++;
if (nused == nmax)
goto full;
nused++;
*ndata++ = c;
saw_bitstring = ISC_TRUE;
state = fw_bitstring;
} else if (c == DNS_LABELTYPE_GLOBALCOMP16) {
/*
* 16-bit pointer.
*/
if ((dctx->allowed & DNS_COMPRESS_GLOBAL16) ==
0)
return (DNS_R_DISALLOWED);
new_current = 0;
n = 2;
state = fw_newcurrent;
} else
return (DNS_R_BADLABELTYPE);
break;
case fw_ordinary:
if (downcase)
c = maptolower[c];
/* FALLTHROUGH */
case fw_copy:
*ndata++ = c;
n--;
if (n == 0)
state = fw_start;
break;
case fw_bitstring:
if (c == 0)
n = 256 / 8;
else
n = c / 8;
if ((c % 8) != 0)
n++;
if (nused + n + 1 > nmax)
goto full;
nused += n + 1;
*ndata++ = c;
state = fw_copy;
break;
case fw_newcurrent:
new_current *= 256;
new_current += c;
n--;
if (n != 0)
break;
if (new_current >= biggest_pointer)
return (DNS_R_BADPOINTER);
biggest_pointer = new_current;
current = new_current;
cdata = (unsigned char *)source->base +
current;
hops++;
if (hops > DNS_POINTER_MAXHOPS)
return (DNS_R_TOOMANYHOPS);
state = fw_start;
break;
default:
FATAL_ERROR(__FILE__, __LINE__,
"Unknown state %d", state);
/* Does not return. */
}
}
if (!done)
return (ISC_R_UNEXPECTEDEND);
name->ndata = (unsigned char *)target->base + target->used;
name->labels = labels;
name->length = nused;
name->attributes |= DNS_NAMEATTR_ABSOLUTE;
/*
* We should build the offsets table directly.
*/
if (name->offsets != NULL || saw_bitstring)
set_offsets(name, offsets, NULL);
if (saw_bitstring)
compact(name, offsets);
isc_buffer_forward(source, cused);
isc_buffer_add(target, name->length);
return (ISC_R_SUCCESS);
full:
if (nmax == DNS_NAME_MAXWIRE)
/*
* The name did not fit even though we had a buffer
* big enough to fit a maximum-length name.
*/
return (DNS_R_NAMETOOLONG);
else
/*
* The name might fit if only the caller could give us a
* big enough buffer.
*/
return (ISC_R_NOSPACE);
}
isc_result_t
dns_name_towire(dns_name_t *name, dns_compress_t *cctx, isc_buffer_t *target) {
unsigned int methods;
isc_uint16_t offset;
dns_name_t gp, gs;
isc_boolean_t gf;
isc_uint16_t go;
unsigned char gb[257];
isc_buffer_t gws;
dns_offsets_t po, so, 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);
/*
* 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, po);
dns_name_init(&gs, so);
isc_buffer_init(&gws, gb, sizeof (gb));
offset = target->used; /*XXX*/
methods = dns_compress_getmethods(cctx);
if ((methods & DNS_COMPRESS_GLOBAL) != 0)
gf = dns_compress_findglobal(cctx, name, &gp, &gs, &go, &gws);
else
gf = ISC_FALSE;
/*
* Will the compression pointer reduce the message size?
*/
if (gf && (gp.length + ((go < 16384) ? 2 : 3)) >= name->length)
gf = ISC_FALSE;
if (gf) {
if (target->length - target->used < gp.length)
return (ISC_R_NOSPACE);
(void)memcpy((unsigned char *)target->base + target->used,
gp.ndata, (size_t)gp.length);
isc_buffer_add(target, gp.length);
if (go < 16384) {
go |= 0xc000;
if (target->length - target->used < 2)
return (ISC_R_NOSPACE);
isc_buffer_putuint16(target, go);
} else {
if (target->length - target->used < 3)
return (ISC_R_NOSPACE);
*((unsigned char*)target->base + target->used) =
DNS_LABELTYPE_GLOBALCOMP16;
isc_buffer_add(target, 1);
isc_buffer_putuint16(target, go);
}
if (gp.length != 0)
dns_compress_add(cctx, &gp, &gs, offset);
} else {
if (target->length - target->used < name->length)
return (ISC_R_NOSPACE);
(void)memcpy((unsigned char *)target->base + target->used,
name->ndata, (size_t)name->length);
isc_buffer_add(target, name->length);
dns_compress_add(cctx, name, NULL, offset);
}
return (ISC_R_SUCCESS);
}
isc_result_t
dns_name_concatenate(dns_name_t *prefix, dns_name_t *suffix, dns_name_t *name,
isc_buffer_t *target)
{
unsigned char *ndata, *offsets;
unsigned int nrem, labels, prefix_length, length, offset;
isc_boolean_t copy_prefix = ISC_TRUE;
isc_boolean_t copy_suffix = ISC_TRUE;
isc_boolean_t saw_bitstring = ISC_FALSE;
isc_boolean_t absolute = ISC_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));
if (prefix == NULL || prefix->labels == 0)
copy_prefix = ISC_FALSE;
if (suffix == NULL || suffix->labels == 0)
copy_suffix = ISC_FALSE;
if (copy_prefix &&
(prefix->attributes & DNS_NAMEATTR_ABSOLUTE) != 0) {
absolute = ISC_TRUE;
REQUIRE(!copy_suffix);
}
if (name == NULL) {
dns_name_init(&tmp_name, odata);
name = &tmp_name;
}
if (target == NULL && name->buffer != NULL) {
target = name->buffer;
isc_buffer_clear(name->buffer);
}
REQUIRE(BINDABLE(name));
/*
* XXX IMPORTANT NOTE
*
* If the most-signficant label in prefix is a bitstring,
* and the least-signficant label in suffix is a bitstring,
* it's possible that compaction could convert them into
* one label. If this happens, then the final size will
* be three bytes less than nrem.
*
* We do not check for this special case, and handling it is
* a little messy; we can't just concatenate and compact,
* because we may only have 255 bytes but might need 258 bytes
* temporarily. There are ways to do this with only 255 bytes,
* which will be implemented later.
*
* For now, we simply reject these few cases as being too
* long.
*/
/*
* 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 = ISC_TRUE;
if (copy_prefix &&
suffix->ndata[0] == DNS_LABELTYPE_BITSTRING) {
/*
* We only need to call compact() if both the
* least-significant label of the suffix and the
* most-significant label of the prefix are both
* bitstrings.
*
* A further possible optimization, which we don't do,
* is to not compact() if the suffix bitstring is
* full. It will usually not be full, so I don't
* think this is worth it.
*/
if (prefix->offsets != NULL) {
offset = prefix->offsets[prefix->labels - 1];
if (prefix->ndata[offset] ==
DNS_LABELTYPE_BITSTRING)
saw_bitstring = ISC_TRUE;
} else {
/*
* We don't have an offsets table for prefix,
* and rather than spend the effort to make it
* we'll just compact(), which doesn't cost
* more than computing the offsets table if
* there is no bitstring in prefix.
*/
saw_bitstring = ISC_TRUE;
}
}
if (suffix == name && suffix->buffer == target)
memmove(ndata + prefix_length, suffix->ndata,
suffix->length);
else
memcpy(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))
memcpy(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 || saw_bitstring)) {
INIT_OFFSETS(name, offsets, odata);
set_offsets(name, offsets, NULL);
if (saw_bitstring)
compact(name, offsets);
}
isc_buffer_add(target, name->length);
return (ISC_R_SUCCESS);
}
isc_result_t
dns_name_split(dns_name_t *name,
unsigned int suffixlabels, unsigned int nbits,
dns_name_t *prefix, dns_name_t *suffix)
{
dns_offsets_t name_odata, split_odata;
unsigned char *offsets, *splitoffsets;
isc_result_t result = ISC_R_SUCCESS;
unsigned int splitlabel, bitbytes, mod, len;
unsigned char *p, *src, *dst;
REQUIRE(VALID_NAME(name));
REQUIRE((nbits == 0 &&
suffixlabels > 0 && suffixlabels < name->labels) ||
(nbits != 0 &&
suffixlabels <= name->labels));
REQUIRE(prefix != NULL || suffix != NULL);
REQUIRE(prefix == NULL ||
(VALID_NAME(prefix) &&
prefix->buffer != NULL &&
BINDABLE(prefix)));
REQUIRE(suffix == NULL ||
(VALID_NAME(suffix) &&
suffix->buffer != NULL &&
BINDABLE(suffix)));
/*
* When splitting bitstring labels, if prefix and suffix have the same
* buffer, suffix will overwrite the ndata of prefix, corrupting it.
* If prefix has the ndata of name, then it modifies the bitstring
* label and suffix doesn't have the original available. This latter
* problem could be worked around if it is ever deemed desirable.
*/
REQUIRE(nbits == 0 || prefix == NULL || suffix == NULL ||
(prefix->buffer->base != suffix->buffer->base &&
prefix->buffer->base != name->ndata));
SETUP_OFFSETS(name, offsets, name_odata);
splitlabel = name->labels - suffixlabels;
p = &name->ndata[offsets[splitlabel] + 1];
/*
* When a bit count is specified, ensure that the label is a bitstring
* label and it has more bits than the requested slice.
*/
REQUIRE(nbits == 0 ||
(*(p - 1) == DNS_LABELTYPE_BITSTRING && nbits < 256 &&
(*p == 0 || *p > nbits)));
mod = nbits % 8;
if (prefix != NULL) {
if (nbits > 0) {
isc_buffer_clear(prefix->buffer);
/*
* '2' is for the DNS_LABELTYPE_BITSTRING id
* plus the existing number of bits byte.
*/
len = offsets[splitlabel] + 2;
src = name->ndata;
dst = prefix->buffer->base;
if (src != dst) {
/*
* If these are overlapping names ...
* wow. How bizarre could that be?
*/
INSIST(! (src <= dst && src + len > dst) ||
(dst <= src && dst + len > src));
memcpy(dst, src, len);
p = dst + len - 1;
}
/*
* Set the new bit count.
*/
if (*p == 0)
*p = 256 - nbits;
else
*p = *p - nbits;
/*
* Really one less than the bytes for the bits.
*/
bitbytes = (*p - 1) / 8 + 1;
prefix->length = len + bitbytes;
if (prefix->length > prefix->buffer->length ) {
dns_name_invalidate(prefix);
return(ISC_R_NOSPACE);
}
/*
* All of the bits now need to be shifted to the left
* to fill in the space taken by the removed bits.
* This is wonderfully easy when the number of removed
* bits is an integral multiple of 8, but of course
* life isn't always that easy.
*/
src += len + nbits / 8;
dst = p + 1;
len = bitbytes;
if (mod == 0) {
if ((void *)(name->ndata) ==
prefix->buffer->base &&
len > (unsigned int)(src - dst))
memmove(dst, src, len);
else
memcpy(dst, src, len);
} else {
/*
* p is adjusted to point to the last byte of
* the starting bitstring label to make it
* cheap to determine when bits from the next
* byte should be shifted into the low order
* bits of the current byte.
*/
p = src + (mod + *p - 1) / 8;
while (len--) {
*dst = *src++ << mod;
/*
* The 0xff subexpression guards
* against arithmetic sign extension
* by the right shift.
*/
if (src <= p)
*dst++ |=
(*src >> (8 - mod)) &
~(0xFF << mod);
}
/*
* Et voila, the very last byte has
* automatically already had its padding
* fixed by the left shift.
*/
}
prefix->buffer->used = prefix->length;
prefix->ndata = prefix->buffer->base;
/*
* Yes, = is meant here, not ==. The intent is
* to have it set only when INSISTs are turned on,
* to doublecheck the result of set_offsets.
*/
INSIST(len = prefix->length);
INIT_OFFSETS(prefix, splitoffsets, split_odata);
set_offsets(prefix, splitoffsets, prefix);
INSIST(prefix->labels == splitlabel + 1 &&
prefix->length == len);
} else
dns_name_getlabelsequence(name, 0, splitlabel,
prefix);
}
if (suffix != NULL && result == ISC_R_SUCCESS) {
if (nbits > 0) {
bitbytes = (nbits - 1) / 8 + 1;
isc_buffer_clear(suffix->buffer);
/*
* The existing bitcount is in src.
* Set len to the number of bytes to be removed,
* and the suffix length to the number of bytes in
* the new name.
*/
src = &name->ndata[offsets[splitlabel] + 1];
len = (*src++ - 1) / 8 - (bitbytes - 1);
suffix->length = name->length -
offsets[splitlabel] - len;
INSIST(suffix->length > 0);
if (suffix->length > suffix->buffer->length) {
dns_name_invalidate(suffix);
return (ISC_R_NOSPACE);
}
/*
* First set up the bitstring label.
*/
dst = suffix->buffer->base;
*dst++ = DNS_LABELTYPE_BITSTRING;
*dst++ = nbits;
if (len > 0) {
/*
* Remember where the next label starts.
*/
p = src + bitbytes + len;
/*
* Some bytes are being removed from the
* middle of the name because of the truncation
* of bits in the bitstring label. Copy
* the bytes (whether full with 8 bits or not)
* that are being kept.
*/
for (len = bitbytes; len > 0; len--)
*dst++ = *src++;
/*
* Now just copy the rest of the labels of
* the name by adjusting src to point to
* the next label.
*
* 2 == label type byte + bitcount byte.
*/
len = suffix->length - bitbytes - 2;
src = p;
} else
len = suffix->length - 2;
/*
* XXX DCL better way to decide memcpy vs memmove?
*/
if (len > 0) {
if ((dst <= src && dst + len > src) ||
(src <= dst && src + len > dst))
memmove(dst, src, len);
else
memcpy(dst, src, len);
}
suffix->buffer->used = suffix->length;
suffix->ndata = suffix->buffer->base;
/*
* The byte that contains the end of the
* bitstring has its pad bytes (if any) masked
* to zero.
*/
if (mod)
suffix->ndata[bitbytes + 1] &=
0xFF << (8 - mod);
/*
* Yes, = is meant here, not ==. The intent is
* to have it set only when INSISTs are turned on,
* to doublecheck the result of set_offsets.
*/
INSIST(len = suffix->length);
INIT_OFFSETS(suffix, splitoffsets, split_odata);
set_offsets(suffix, splitoffsets, suffix);
INSIST(suffix->labels == suffixlabels &&
suffix->length == len);
} else
dns_name_getlabelsequence(name, splitlabel,
suffixlabels, suffix);
}
return (result);
}
isc_result_t
dns_name_splitatdepth(dns_name_t *name, unsigned int depth,
dns_name_t *prefix, dns_name_t *suffix)
{
unsigned int suffixlabels, nbits, label, count, n;
unsigned char *offsets, *ndata;
dns_offsets_t odata;
/*
* Split 'name' into two pieces at a certain depth.
*/
REQUIRE(VALID_NAME(name));
REQUIRE(name->labels > 0);
REQUIRE(depth > 0);
SETUP_OFFSETS(name, offsets, odata);
suffixlabels = 0;
nbits = 0;
label = name->labels;
do {
label--;
ndata = &name->ndata[offsets[label]];
count = *ndata++;
if (count > 63) {
INSIST(count == DNS_LABELTYPE_BITSTRING);
/*
* Get the number of bits in the bitstring label.
*/
n = *ndata++;
if (n == 0)
n = 256;
suffixlabels++;
if (n <= depth) {
/*
* This entire bitstring is in the suffix.
*/
depth -= n;
} else {
/*
* Only the first 'depth' bits of this
* bitstring are in the suffix.
*/
nbits = depth;
depth = 0;
}
} else {
suffixlabels++;
depth--;
}
} while (depth != 0 && label != 0);
/*
* If depth is not zero, then the caller violated the requirement
* that depth <= dns_name_depth(name).
*/
if (depth != 0) {
REQUIRE(depth <= dns_name_depth(name));
/*
* We should never get here!
*/
INSIST(0);
}
return (dns_name_split(name, suffixlabels, nbits, prefix, suffix));
}
isc_result_t
dns_name_dup(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);
if (target->ndata == NULL)
return (ISC_R_NOMEMORY);
memcpy(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)
memcpy(target->offsets, source->offsets,
source->labels);
else
set_offsets(target, target->offsets, NULL);
}
return (ISC_R_SUCCESS);
}
isc_result_t
dns_name_dupwithoffsets(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);
if (target->ndata == NULL)
return (ISC_R_NOMEMORY);
memcpy(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)
memcpy(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(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));
}
isc_boolean_t
dns_name_dynamic(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 ?
ISC_TRUE : ISC_FALSE);
}
isc_result_t
dns_name_print(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, ISC_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);
}
void
dns_name_format(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, ISC_TRUE, &buf);
if (result == ISC_R_SUCCESS) {
/*
* Null terminate.
*/
isc_region_t r;
isc_buffer_usedregion(&buf, &r);
((char *) r.base)[r.length] = '\0';
} else
snprintf(cp, size, "<unknown>");
}