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bind/lib/dns/rbt.c
Artem Boldariev a236151608 Fix build with DEBUG defined (-DDEBUG) 
The problem was introduced by commit 98b55eb4.
2020-11-06 12:20:41 +02:00

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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* 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 <inttypes.h>
#include <stdbool.h>
#include <sys/stat.h>
#include <isc/crc64.h>
#include <isc/file.h>
#include <isc/hex.h>
#include <isc/mem.h>
#include <isc/once.h>
#include <isc/platform.h>
#include <isc/print.h>
#include <isc/refcount.h>
#include <isc/socket.h>
#include <isc/stdio.h>
#include <isc/string.h>
#include <isc/util.h>
/*%
* This define is so dns/name.h (included by dns/fixedname.h) uses more
* efficient macro calls instead of functions for a few operations.
*/
#define DNS_NAME_USEINLINE 1
#include <unistd.h>
#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/rbt.h>
#include <dns/result.h>
#define CHECK(x) \
do { \
result = (x); \
if (result != ISC_R_SUCCESS) \
goto cleanup; \
} while (0)
#define RBT_MAGIC ISC_MAGIC('R', 'B', 'T', '+')
#define VALID_RBT(rbt) ISC_MAGIC_VALID(rbt, RBT_MAGIC)
/*
* XXXDCL Since parent pointers were added in again, I could remove all of the
* chain junk, and replace with dns_rbt_firstnode, _previousnode, _nextnode,
* _lastnode. This would involve pretty major change to the API.
*/
#define CHAIN_MAGIC ISC_MAGIC('0', '-', '0', '-')
#define VALID_CHAIN(chain) ISC_MAGIC_VALID(chain, CHAIN_MAGIC)
#define RBT_HASH_MIN_BITS 4
#define RBT_HASH_MAX_BITS 32
#define RBT_HASH_OVERCOMMIT 3
#define RBT_HASH_BUCKETSIZE 4096 /* FIXME: What would be a good value here? */
#ifdef RBT_MEM_TEST
#undef RBT_HASH_SIZE
#define RBT_HASH_SIZE 2 /*%< To give the reallocation code a workout. */
#endif /* ifdef RBT_MEM_TEST */
#define GOLDEN_RATIO_32 0x61C88647
#define HASHSIZE(bits) (UINT64_C(1) << (bits))
static inline uint32_t
hash_32(uint32_t val, unsigned int bits) {
REQUIRE(bits <= RBT_HASH_MAX_BITS);
/* High bits are more random. */
return (val * GOLDEN_RATIO_32 >> (32 - bits));
}
struct dns_rbt {
unsigned int magic;
isc_mem_t *mctx;
dns_rbtnode_t *root;
void (*data_deleter)(void *, void *);
void *deleter_arg;
unsigned int nodecount;
uint16_t hashbits;
uint16_t maxhashbits;
dns_rbtnode_t **hashtable;
void *mmap_location;
};
#define RED 0
#define BLACK 1
/*
* This is the header for map-format RBT images. It is populated,
* and then written, as the LAST thing done to the file before returning.
* Writing this last (with zeros in the header area initially) will ensure
* that the header is only valid when the RBT image is also valid.
*/
typedef struct file_header file_header_t;
/* Pad to 32 bytes */
static char FILE_VERSION[32] = "\0";
/* Header length, always the same size regardless of structure size */
#define HEADER_LENGTH 1024
struct file_header {
char version1[32];
uint64_t first_node_offset; /* usually 1024 */
/*
* information about the system on which the map file was generated
* will be used to tell if we can load the map file or not
*/
uint32_t ptrsize;
unsigned int bigendian : 1; /* big or little endian system */
unsigned int rdataset_fixed : 1; /* compiled with
* --enable-rrset-fixed
*/
unsigned int nodecount; /* shadow from rbt structure */
uint64_t crc;
char version2[32]; /* repeated; must match version1 */
};
/*
* The following declarations are for the serialization of an RBT:
*
* step one: write out a zeroed header of 1024 bytes
* step two: walk the tree in a depth-first, left-right-down order, writing
* out the nodes, reserving space as we go, correcting addresses to point
* at the proper offset in the file, and setting a flag for each pointer to
* indicate that it is a reference to a location in the file, rather than in
* memory.
* step three: write out the header, adding the information that will be
* needed to re-create the tree object itself.
*
* The RBTDB object will do this three times, once for each of the three
* RBT objects it contains.
*
* Note: 'file' must point an actual open file that can be mmapped
* and fseeked, not to a pipe or stream
*/
static isc_result_t
dns_rbt_zero_header(FILE *file);
static isc_result_t
write_header(FILE *file, dns_rbt_t *rbt, uint64_t first_node_offset,
uint64_t crc);
static bool
match_header_version(file_header_t *header);
static isc_result_t
serialize_node(FILE *file, dns_rbtnode_t *node, uintptr_t left, uintptr_t right,
uintptr_t down, uintptr_t parent, uintptr_t data, uint64_t *crc);
static isc_result_t
serialize_nodes(FILE *file, dns_rbtnode_t *node, uintptr_t parent,
dns_rbtdatawriter_t datawriter, void *writer_arg,
uintptr_t *where, uint64_t *crc);
/*
* The following functions allow you to get the actual address of a pointer
* without having to use an if statement to check to see if that address is
* relative or not
*/
static inline dns_rbtnode_t *
getparent(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->parent);
adjusted_address += node->parent_is_relative * (uintptr_t)header;
return ((dns_rbtnode_t *)adjusted_address);
}
static inline dns_rbtnode_t *
getleft(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->left);
adjusted_address += node->left_is_relative * (uintptr_t)header;
return ((dns_rbtnode_t *)adjusted_address);
}
static inline dns_rbtnode_t *
getright(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->right);
adjusted_address += node->right_is_relative * (uintptr_t)header;
return ((dns_rbtnode_t *)adjusted_address);
}
static inline dns_rbtnode_t *
getdown(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->down);
adjusted_address += node->down_is_relative * (uintptr_t)header;
return ((dns_rbtnode_t *)adjusted_address);
}
static inline dns_rbtnode_t *
getdata(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->data);
adjusted_address += node->data_is_relative * (uintptr_t)header;
return ((dns_rbtnode_t *)adjusted_address);
}
/*%
* Elements of the rbtnode structure.
*/
#define PARENT(node) ((node)->parent)
#define LEFT(node) ((node)->left)
#define RIGHT(node) ((node)->right)
#define DOWN(node) ((node)->down)
#define UPPERNODE(node) ((node)->uppernode)
#define DATA(node) ((node)->data)
#define IS_EMPTY(node) ((node)->data == NULL)
#define HASHNEXT(node) ((node)->hashnext)
#define HASHVAL(node) ((node)->hashval)
#define COLOR(node) ((node)->color)
#define NAMELEN(node) ((node)->namelen)
#define OLDNAMELEN(node) ((node)->oldnamelen)
#define OFFSETLEN(node) ((node)->offsetlen)
#define ATTRS(node) ((node)->attributes)
#define IS_ROOT(node) ((node)->is_root)
#define FINDCALLBACK(node) ((node)->find_callback)
#define WANTEMPTYDATA_OR_DATA(options, node) \
((options & DNS_RBTFIND_EMPTYDATA) != 0 || DATA(node) != NULL)
/*%
* Structure elements from the rbtdb.c, not
* used as part of the rbt.c algorithms.
*/
#define DIRTY(node) ((node)->dirty)
#define WILD(node) ((node)->wild)
#define LOCKNUM(node) ((node)->locknum)
/*%
* The variable length stuff stored after the node has the following
* structure.
*
* &lt;name_data&gt;{1..255}&lt;oldoffsetlen&gt;{1}&lt;offsets&gt;{1..128}
*
* &lt;name_data&gt; contains the name of the node when it was created.
* &lt;oldoffsetlen&gt; contains the length of &lt;offsets&gt; when the node
* was created.
* &lt;offsets&gt; contains the offsets into name for each label when the node
* was created.
*/
#define NAME(node) ((unsigned char *)((node) + 1))
#define OFFSETS(node) (NAME(node) + OLDNAMELEN(node) + 1)
#define OLDOFFSETLEN(node) (OFFSETS(node)[-1])
#define NODE_SIZE(node) \
(sizeof(*node) + OLDNAMELEN(node) + OLDOFFSETLEN(node) + 1)
/*%
* Color management.
*/
#define IS_RED(node) ((node) != NULL && (node)->color == RED)
#define IS_BLACK(node) ((node) == NULL || (node)->color == BLACK)
#define MAKE_RED(node) ((node)->color = RED)
#define MAKE_BLACK(node) ((node)->color = BLACK)
/*%
* Chain management.
*
* The "ancestors" member of chains were removed, with their job now
* being wholly handled by parent pointers (which didn't exist, because
* of memory concerns, when chains were first implemented).
*/
#define ADD_LEVEL(chain, node) \
do { \
INSIST((chain)->level_count < DNS_RBT_LEVELBLOCK); \
(chain)->levels[(chain)->level_count++] = (node); \
} while (0)
/*%
* The following macros directly access normally private name variables.
* These macros are used to avoid a lot of function calls in the critical
* path of the tree traversal code.
*/
static inline void
NODENAME(dns_rbtnode_t *node, dns_name_t *name) {
name->length = NAMELEN(node);
name->labels = OFFSETLEN(node);
name->ndata = NAME(node);
name->offsets = OFFSETS(node);
name->attributes = ATTRS(node);
name->attributes |= DNS_NAMEATTR_READONLY;
}
#ifdef DEBUG
#define inline
/*
* A little something to help out in GDB.
*/
dns_name_t
Name(dns_rbtnode_t *node);
dns_name_t
Name(dns_rbtnode_t *node) {
dns_name_t name;
dns_name_init(&name, NULL);
if (node != NULL) {
NODENAME(node, &name);
}
return (name);
}
static void
hexdump(const char *desc, unsigned char *data, size_t size) {
char hexdump[BUFSIZ * 2 + 1];
isc_buffer_t b;
isc_region_t r;
isc_result_t result;
size_t bytes;
fprintf(stderr, "%s: ", desc);
do {
isc_buffer_init(&b, hexdump, sizeof(hexdump));
r.base = data;
r.length = bytes = (size > BUFSIZ) ? BUFSIZ : size;
result = isc_hex_totext(&r, 0, "", &b);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
isc_buffer_putuint8(&b, 0);
fprintf(stderr, "%s", hexdump);
data += bytes;
size -= bytes;
} while (size > 0);
fprintf(stderr, "\n");
}
#endif /* DEBUG */
/*
* Upper node is the parent of the root of the passed node's
* subtree. The passed node must not be NULL.
*/
static inline dns_rbtnode_t *
get_upper_node(dns_rbtnode_t *node) {
return (UPPERNODE(node));
}
static void
fixup_uppernodes_helper(dns_rbtnode_t *node, dns_rbtnode_t *uppernode) {
if (node == NULL) {
return;
}
UPPERNODE(node) = uppernode;
fixup_uppernodes_helper(LEFT(node), uppernode);
fixup_uppernodes_helper(RIGHT(node), uppernode);
fixup_uppernodes_helper(DOWN(node), node);
}
/*
* This function is used to fixup uppernode members of all dns_rbtnodes
* after deserialization.
*/
static void
fixup_uppernodes(dns_rbt_t *rbt) {
fixup_uppernodes_helper(rbt->root, NULL);
}
size_t
dns__rbtnode_getdistance(dns_rbtnode_t *node) {
size_t nodes = 1;
while (node != NULL) {
if (IS_ROOT(node)) {
break;
}
nodes++;
node = PARENT(node);
}
return (nodes);
}
/*
* Forward declarations.
*/
static isc_result_t
create_node(isc_mem_t *mctx, const dns_name_t *name, dns_rbtnode_t **nodep);
static isc_result_t
inithash(dns_rbt_t *rbt);
static inline void
hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node, const dns_name_t *name);
static inline void
unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node);
static uint32_t
rehash_bits(dns_rbt_t *rbt, size_t newcount);
static void
rehash(dns_rbt_t *rbt, uint32_t newbits);
static void
maybe_rehash(dns_rbt_t *rbt, size_t size);
static inline void
rotate_left(dns_rbtnode_t *node, dns_rbtnode_t **rootp);
static inline void
rotate_right(dns_rbtnode_t *node, dns_rbtnode_t **rootp);
static void
addonlevel(dns_rbtnode_t *node, dns_rbtnode_t *current, int order,
dns_rbtnode_t **rootp);
static void
deletefromlevel(dns_rbtnode_t *item, dns_rbtnode_t **rootp);
static isc_result_t
treefix(dns_rbt_t *rbt, void *base, size_t size, dns_rbtnode_t *n,
const dns_name_t *name, dns_rbtdatafixer_t datafixer, void *fixer_arg,
uint64_t *crc);
static void
deletetreeflat(dns_rbt_t *rbt, unsigned int quantum, bool unhash,
dns_rbtnode_t **nodep);
static void
printnodename(dns_rbtnode_t *node, bool quoted, FILE *f);
static void
freenode(dns_rbt_t *rbt, dns_rbtnode_t **nodep);
static isc_result_t
dns_rbt_zero_header(FILE *file) {
/*
* Write out a zeroed header as a placeholder. Doing this ensures
* that the file will not read while it is partially written, should
* writing fail or be interrupted.
*/
char buffer[HEADER_LENGTH];
isc_result_t result;
memset(buffer, 0, HEADER_LENGTH);
result = isc_stdio_write(buffer, 1, HEADER_LENGTH, file, NULL);
if (result != ISC_R_SUCCESS) {
return (result);
}
result = fflush(file);
if (result != ISC_R_SUCCESS) {
return (result);
}
return (ISC_R_SUCCESS);
}
static isc_once_t once = ISC_ONCE_INIT;
static void
init_file_version(void) {
int n;
memset(FILE_VERSION, 0, sizeof(FILE_VERSION));
n = snprintf(FILE_VERSION, sizeof(FILE_VERSION), "RBT Image %s %s",
PACKAGE_VERSION_MAJOR, MAPAPI);
INSIST(n > 0 && (unsigned int)n < sizeof(FILE_VERSION));
}
/*
* Write out the real header, including NodeDump version information
* and the offset of the first node.
*
* Any information stored in the rbt object itself should be stored
* here.
*/
static isc_result_t
write_header(FILE *file, dns_rbt_t *rbt, uint64_t first_node_offset,
uint64_t crc) {
file_header_t header;
isc_result_t result;
off_t location;
RUNTIME_CHECK(isc_once_do(&once, init_file_version) == ISC_R_SUCCESS);
memset(&header, 0, sizeof(file_header_t));
memmove(header.version1, FILE_VERSION, sizeof(header.version1));
memmove(header.version2, FILE_VERSION, sizeof(header.version2));
header.first_node_offset = first_node_offset;
header.ptrsize = (uint32_t)sizeof(void *);
header.bigendian = (1 == htonl(1)) ? 1 : 0;
#ifdef DNS_RDATASET_FIXED
header.rdataset_fixed = 1;
#else /* ifdef DNS_RDATASET_FIXED */
header.rdataset_fixed = 0;
#endif /* ifdef DNS_RDATASET_FIXED */
header.nodecount = rbt->nodecount;
header.crc = crc;
CHECK(isc_stdio_tell(file, &location));
location = dns_rbt_serialize_align(location);
CHECK(isc_stdio_seek(file, location, SEEK_SET));
CHECK(isc_stdio_write(&header, 1, sizeof(file_header_t), file, NULL));
CHECK(fflush(file));
/* Ensure we are always at the end of the file. */
CHECK(isc_stdio_seek(file, 0, SEEK_END));
cleanup:
return (result);
}
static bool
match_header_version(file_header_t *header) {
RUNTIME_CHECK(isc_once_do(&once, init_file_version) == ISC_R_SUCCESS);
if (memcmp(header->version1, FILE_VERSION, sizeof(header->version1)) !=
0 ||
memcmp(header->version2, FILE_VERSION, sizeof(header->version1)) !=
0)
{
return (false);
}
return (true);
}
unsigned int
dns__rbtnode_namelen(dns_rbtnode_t *node) {
dns_name_t current;
unsigned int len = 0;
REQUIRE(DNS_RBTNODE_VALID(node));
dns_name_init(&current, NULL);
do {
if (node != NULL) {
NODENAME(node, &current);
len += current.length;
} else {
len += 1;
break;
}
node = get_upper_node(node);
} while (!dns_name_isabsolute(&current));
return (len);
}
static isc_result_t
serialize_node(FILE *file, dns_rbtnode_t *node, uintptr_t left, uintptr_t right,
uintptr_t down, uintptr_t parent, uintptr_t data,
uint64_t *crc) {
isc_result_t result;
dns_rbtnode_t temp_node;
off_t file_position;
unsigned char *node_data = NULL;
size_t datasize;
#ifdef DEBUG
dns_name_t nodename;
#endif /* ifdef DEBUG */
INSIST(node != NULL);
CHECK(isc_stdio_tell(file, &file_position));
file_position = dns_rbt_serialize_align(file_position);
CHECK(isc_stdio_seek(file, file_position, SEEK_SET));
temp_node = *node;
temp_node.down_is_relative = 0;
temp_node.left_is_relative = 0;
temp_node.right_is_relative = 0;
temp_node.parent_is_relative = 0;
temp_node.data_is_relative = 0;
temp_node.is_mmapped = 1;
/*
* If the next node is not NULL, calculate the next node's location
* in the file. Note that this will have to change when the data
* structure changes, and it also assumes that we always write the
* nodes out in list order (which we currently do.)
*/
if (temp_node.parent != NULL) {
temp_node.parent = (dns_rbtnode_t *)(parent);
temp_node.parent_is_relative = 1;
}
if (temp_node.left != NULL) {
temp_node.left = (dns_rbtnode_t *)(left);
temp_node.left_is_relative = 1;
}
if (temp_node.right != NULL) {
temp_node.right = (dns_rbtnode_t *)(right);
temp_node.right_is_relative = 1;
}
if (temp_node.down != NULL) {
temp_node.down = (dns_rbtnode_t *)(down);
temp_node.down_is_relative = 1;
}
if (temp_node.data != NULL) {
temp_node.data = (dns_rbtnode_t *)(data);
temp_node.data_is_relative = 1;
}
temp_node.fullnamelen = dns__rbtnode_namelen(node);
node_data = (unsigned char *)node + sizeof(dns_rbtnode_t);
datasize = NODE_SIZE(node) - sizeof(dns_rbtnode_t);
CHECK(isc_stdio_write(&temp_node, 1, sizeof(dns_rbtnode_t), file,
NULL));
CHECK(isc_stdio_write(node_data, 1, datasize, file, NULL));
#ifdef DEBUG
dns_name_init(&nodename, NULL);
NODENAME(node, &nodename);
fprintf(stderr, "serialize ");
dns_name_print(&nodename, stderr);
fprintf(stderr, "\n");
hexdump("node header", (unsigned char *)&temp_node,
sizeof(dns_rbtnode_t));
hexdump("node data", node_data, datasize);
#endif /* ifdef DEBUG */
isc_crc64_update(crc, (const uint8_t *)&temp_node,
sizeof(dns_rbtnode_t));
isc_crc64_update(crc, (const uint8_t *)node_data, datasize);
cleanup:
return (result);
}
static isc_result_t
serialize_nodes(FILE *file, dns_rbtnode_t *node, uintptr_t parent,
dns_rbtdatawriter_t datawriter, void *writer_arg,
uintptr_t *where, uint64_t *crc) {
uintptr_t left = 0, right = 0, down = 0, data = 0;
off_t location = 0, offset_adjust;
isc_result_t result;
if (node == NULL) {
if (where != NULL) {
*where = 0;
}
return (ISC_R_SUCCESS);
}
/* Reserve space for current node. */
CHECK(isc_stdio_tell(file, &location));
location = dns_rbt_serialize_align(location);
CHECK(isc_stdio_seek(file, location, SEEK_SET));
offset_adjust = dns_rbt_serialize_align(location + NODE_SIZE(node));
CHECK(isc_stdio_seek(file, offset_adjust, SEEK_SET));
/*
* Serialize the rest of the tree.
*
* WARNING: A change in the order (from left, right, down)
* will break the way the crc hash is computed.
*/
CHECK(serialize_nodes(file, getleft(node, NULL), location, datawriter,
writer_arg, &left, crc));
CHECK(serialize_nodes(file, getright(node, NULL), location, datawriter,
writer_arg, &right, crc));
CHECK(serialize_nodes(file, getdown(node, NULL), location, datawriter,
writer_arg, &down, crc));
if (node->data != NULL) {
off_t ret;
CHECK(isc_stdio_tell(file, &ret));
ret = dns_rbt_serialize_align(ret);
CHECK(isc_stdio_seek(file, ret, SEEK_SET));
data = ret;
datawriter(file, node->data, writer_arg, crc);
}
/* Seek back to reserved space. */
CHECK(isc_stdio_seek(file, location, SEEK_SET));
/* Serialize the current node. */
CHECK(serialize_node(file, node, left, right, down, parent, data, crc));
/* Ensure we are always at the end of the file. */
CHECK(isc_stdio_seek(file, 0, SEEK_END));
if (where != NULL) {
*where = (uintptr_t)location;
}
cleanup:
return (result);
}
off_t
dns_rbt_serialize_align(off_t target) {
off_t offset = target % 8;
if (offset == 0) {
return (target);
} else {
return (target + 8 - offset);
}
}
isc_result_t
dns_rbt_serialize_tree(FILE *file, dns_rbt_t *rbt,
dns_rbtdatawriter_t datawriter, void *writer_arg,
off_t *offset) {
isc_result_t result;
off_t header_position, node_position, end_position;
uint64_t crc;
REQUIRE(file != NULL);
CHECK(isc_file_isplainfilefd(fileno(file)));
isc_crc64_init(&crc);
CHECK(isc_stdio_tell(file, &header_position));
/* Write dummy header */
CHECK(dns_rbt_zero_header(file));
/* Serialize nodes */
CHECK(isc_stdio_tell(file, &node_position));
CHECK(serialize_nodes(file, rbt->root, 0, datawriter, writer_arg, NULL,
&crc));
CHECK(isc_stdio_tell(file, &end_position));
if (node_position == end_position) {
CHECK(isc_stdio_seek(file, header_position, SEEK_SET));
*offset = 0;
return (ISC_R_SUCCESS);
}
isc_crc64_final(&crc);
#ifdef DEBUG
hexdump("serializing CRC", (unsigned char *)&crc, sizeof(crc));
#endif /* ifdef DEBUG */
/* Serialize header */
CHECK(isc_stdio_seek(file, header_position, SEEK_SET));
CHECK(write_header(file, rbt, HEADER_LENGTH, crc));
/* Ensure we are always at the end of the file. */
CHECK(isc_stdio_seek(file, 0, SEEK_END));
*offset = dns_rbt_serialize_align(header_position);
cleanup:
return (result);
}
#define CONFIRM(a) \
do { \
if (!(a)) { \
result = ISC_R_INVALIDFILE; \
goto cleanup; \
} \
} while (0);
static isc_result_t
treefix(dns_rbt_t *rbt, void *base, size_t filesize, dns_rbtnode_t *n,
const dns_name_t *name, dns_rbtdatafixer_t datafixer, void *fixer_arg,
uint64_t *crc) {
isc_result_t result = ISC_R_SUCCESS;
dns_fixedname_t fixed;
dns_name_t nodename, *fullname;
unsigned char *node_data;
dns_rbtnode_t header;
size_t datasize, nodemax = filesize - sizeof(dns_rbtnode_t);
if (n == NULL) {
return (ISC_R_SUCCESS);
}
CONFIRM((void *)n >= base);
CONFIRM((char *)n - (char *)base <= (int)nodemax);
CONFIRM(DNS_RBTNODE_VALID(n));
dns_name_init(&nodename, NULL);
NODENAME(n, &nodename);
fullname = &nodename;
CONFIRM(dns_name_isvalid(fullname));
if (!dns_name_isabsolute(&nodename)) {
fullname = dns_fixedname_initname(&fixed);
CHECK(dns_name_concatenate(&nodename, name, fullname, NULL));
}
/* memorize header contents prior to fixup */
memmove(&header, n, sizeof(header));
if (n->left_is_relative) {
CONFIRM(n->left <= (dns_rbtnode_t *)nodemax);
n->left = getleft(n, rbt->mmap_location);
n->left_is_relative = 0;
CONFIRM(DNS_RBTNODE_VALID(n->left));
} else {
CONFIRM(n->left == NULL);
}
if (n->right_is_relative) {
CONFIRM(n->right <= (dns_rbtnode_t *)nodemax);
n->right = getright(n, rbt->mmap_location);
n->right_is_relative = 0;
CONFIRM(DNS_RBTNODE_VALID(n->right));
} else {
CONFIRM(n->right == NULL);
}
if (n->down_is_relative) {
CONFIRM(n->down <= (dns_rbtnode_t *)nodemax);
n->down = getdown(n, rbt->mmap_location);
n->down_is_relative = 0;
CONFIRM(n->down > (dns_rbtnode_t *)n);
CONFIRM(DNS_RBTNODE_VALID(n->down));
} else {
CONFIRM(n->down == NULL);
}
if (n->parent_is_relative) {
CONFIRM(n->parent <= (dns_rbtnode_t *)nodemax);
n->parent = getparent(n, rbt->mmap_location);
n->parent_is_relative = 0;
CONFIRM(n->parent < (dns_rbtnode_t *)n);
CONFIRM(DNS_RBTNODE_VALID(n->parent));
} else {
CONFIRM(n->parent == NULL);
}
if (n->data_is_relative) {
CONFIRM(n->data <= (void *)filesize);
n->data = getdata(n, rbt->mmap_location);
n->data_is_relative = 0;
CONFIRM(n->data > (void *)n);
} else {
CONFIRM(n->data == NULL);
}
hash_node(rbt, n, fullname);
/* a change in the order (from left, right, down) will break hashing*/
if (n->left != NULL) {
CHECK(treefix(rbt, base, filesize, n->left, name, datafixer,
fixer_arg, crc));
}
if (n->right != NULL) {
CHECK(treefix(rbt, base, filesize, n->right, name, datafixer,
fixer_arg, crc));
}
if (n->down != NULL) {
CHECK(treefix(rbt, base, filesize, n->down, fullname, datafixer,
fixer_arg, crc));
}
if (datafixer != NULL && n->data != NULL) {
CHECK(datafixer(n, base, filesize, fixer_arg, crc));
}
rbt->nodecount++;
node_data = (unsigned char *)n + sizeof(dns_rbtnode_t);
datasize = NODE_SIZE(n) - sizeof(dns_rbtnode_t);
#ifdef DEBUG
fprintf(stderr, "deserialize ");
dns_name_print(&nodename, stderr);
fprintf(stderr, "\n");
hexdump("node header", (unsigned char *)&header, sizeof(dns_rbtnode_t));
hexdump("node data", node_data, datasize);
#endif /* ifdef DEBUG */
isc_crc64_update(crc, (const uint8_t *)&header, sizeof(dns_rbtnode_t));
isc_crc64_update(crc, (const uint8_t *)node_data, datasize);
cleanup:
return (result);
}
isc_result_t
dns_rbt_deserialize_tree(void *base_address, size_t filesize,
off_t header_offset, isc_mem_t *mctx,
dns_rbtdeleter_t deleter, void *deleter_arg,
dns_rbtdatafixer_t datafixer, void *fixer_arg,
dns_rbtnode_t **originp, dns_rbt_t **rbtp) {
isc_result_t result = ISC_R_SUCCESS;
file_header_t *header;
dns_rbt_t *rbt = NULL;
uint64_t crc;
unsigned int host_big_endian;
REQUIRE(originp == NULL || *originp == NULL);
REQUIRE(rbtp != NULL && *rbtp == NULL);
isc_crc64_init(&crc);
CHECK(dns_rbt_create(mctx, deleter, deleter_arg, &rbt));
rbt->mmap_location = base_address;
header = (file_header_t *)((char *)base_address + header_offset);
if (!match_header_version(header)) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
#ifdef DNS_RDATASET_FIXED
if (header->rdataset_fixed != 1) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
#else /* ifdef DNS_RDATASET_FIXED */
if (header->rdataset_fixed != 0) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
#endif /* ifdef DNS_RDATASET_FIXED */
if (header->ptrsize != (uint32_t)sizeof(void *)) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
host_big_endian = (1 == htonl(1));
if (header->bigendian != host_big_endian) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
/* Copy other data items from the header into our rbt. */
rbt->root = (dns_rbtnode_t *)((char *)base_address + header_offset +
header->first_node_offset);
if ((header->nodecount * sizeof(dns_rbtnode_t)) > filesize) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
maybe_rehash(rbt, header->nodecount);
CHECK(treefix(rbt, base_address, filesize, rbt->root, dns_rootname,
datafixer, fixer_arg, &crc));
isc_crc64_final(&crc);
#ifdef DEBUG
hexdump("deserializing CRC", (unsigned char *)&crc, sizeof(crc));
#endif /* ifdef DEBUG */
/* Check file hash */
if (header->crc != crc) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
if (header->nodecount != rbt->nodecount) {
result = ISC_R_INVALIDFILE;
goto cleanup;
}
fixup_uppernodes(rbt);
*rbtp = rbt;
if (originp != NULL) {
*originp = rbt->root;
}
cleanup:
if (result != ISC_R_SUCCESS && rbt != NULL) {
rbt->root = NULL;
rbt->nodecount = 0;
dns_rbt_destroy(&rbt);
}
return (result);
}
/*
* Initialize a red/black tree of trees.
*/
isc_result_t
dns_rbt_create(isc_mem_t *mctx, dns_rbtdeleter_t deleter, void *deleter_arg,
dns_rbt_t **rbtp) {
isc_result_t result;
dns_rbt_t *rbt;
REQUIRE(mctx != NULL);
REQUIRE(rbtp != NULL && *rbtp == NULL);
REQUIRE(deleter == NULL ? deleter_arg == NULL : 1);
rbt = isc_mem_get(mctx, sizeof(*rbt));
rbt->mctx = NULL;
isc_mem_attach(mctx, &rbt->mctx);
rbt->data_deleter = deleter;
rbt->deleter_arg = deleter_arg;
rbt->root = NULL;
rbt->nodecount = 0;
rbt->hashtable = NULL;
rbt->hashbits = 0;
rbt->maxhashbits = RBT_HASH_MAX_BITS;
rbt->mmap_location = NULL;
result = inithash(rbt);
if (result != ISC_R_SUCCESS) {
isc_mem_putanddetach(&rbt->mctx, rbt, sizeof(*rbt));
return (result);
}
rbt->magic = RBT_MAGIC;
*rbtp = rbt;
return (ISC_R_SUCCESS);
}
/*
* Deallocate a red/black tree of trees.
*/
void
dns_rbt_destroy(dns_rbt_t **rbtp) {
RUNTIME_CHECK(dns_rbt_destroy2(rbtp, 0) == ISC_R_SUCCESS);
}
isc_result_t
dns_rbt_destroy2(dns_rbt_t **rbtp, unsigned int quantum) {
dns_rbt_t *rbt;
REQUIRE(rbtp != NULL && VALID_RBT(*rbtp));
rbt = *rbtp;
deletetreeflat(rbt, quantum, false, &rbt->root);
if (rbt->root != NULL) {
return (ISC_R_QUOTA);
}
*rbtp = NULL;
INSIST(rbt->nodecount == 0);
rbt->mmap_location = NULL;
if (rbt->hashtable != NULL) {
size_t size = HASHSIZE(rbt->hashbits) * sizeof(dns_rbtnode_t *);
isc_mem_put(rbt->mctx, rbt->hashtable, size);
}
rbt->magic = 0;
isc_mem_putanddetach(&rbt->mctx, rbt, sizeof(*rbt));
return (ISC_R_SUCCESS);
}
unsigned int
dns_rbt_nodecount(dns_rbt_t *rbt) {
REQUIRE(VALID_RBT(rbt));
return (rbt->nodecount);
}
size_t
dns_rbt_hashsize(dns_rbt_t *rbt) {
REQUIRE(VALID_RBT(rbt));
return (1 << rbt->hashbits);
}
isc_result_t
dns_rbt_adjusthashsize(dns_rbt_t *rbt, size_t size) {
REQUIRE(VALID_RBT(rbt));
size_t newsize = size / RBT_HASH_BUCKETSIZE;
rbt->maxhashbits = rehash_bits(rbt, newsize);
maybe_rehash(rbt, newsize);
return (ISC_R_SUCCESS);
}
static inline isc_result_t
chain_name(dns_rbtnodechain_t *chain, dns_name_t *name,
bool include_chain_end) {
dns_name_t nodename;
isc_result_t result = ISC_R_SUCCESS;
int i;
dns_name_init(&nodename, NULL);
if (include_chain_end && chain->end != NULL) {
NODENAME(chain->end, &nodename);
dns_name_copynf(&nodename, name);
} else {
dns_name_reset(name);
}
for (i = (int)chain->level_count - 1; i >= 0; i--) {
NODENAME(chain->levels[i], &nodename);
result = dns_name_concatenate(name, &nodename, name, NULL);
if (result != ISC_R_SUCCESS) {
return (result);
}
}
return (result);
}
static inline isc_result_t
move_chain_to_last(dns_rbtnodechain_t *chain, dns_rbtnode_t *node) {
do {
/*
* Go as far right and then down as much as possible,
* as long as the rightmost node has a down pointer.
*/
while (RIGHT(node) != NULL) {
node = RIGHT(node);
}
if (DOWN(node) == NULL) {
break;
}
ADD_LEVEL(chain, node);
node = DOWN(node);
} while (1);
chain->end = node;
return (ISC_R_SUCCESS);
}
/*
* Add 'name' to tree, initializing its data pointer with 'data'.
*/
isc_result_t
dns_rbt_addnode(dns_rbt_t *rbt, const dns_name_t *name, dns_rbtnode_t **nodep) {
/*
* Does this thing have too many variables or what?
*/
dns_rbtnode_t **root, *parent, *child, *current, *new_current;
dns_name_t *add_name, *new_name, current_name, *prefix, *suffix;
dns_fixedname_t fixedcopy, fixedprefix, fixedsuffix, fnewname;
dns_offsets_t current_offsets;
dns_namereln_t compared;
isc_result_t result = ISC_R_SUCCESS;
unsigned int level_count;
unsigned int common_labels;
unsigned int nlabels, hlabels;
int order;
REQUIRE(VALID_RBT(rbt));
REQUIRE(dns_name_isabsolute(name));
REQUIRE(nodep != NULL && *nodep == NULL);
/*
* Dear future BIND developer,
*
* After you have tried attempting to optimize this routine by
* using the hashtable and have realized your folly, please
* append another cross ("X") below as a warning to the next
* future BIND developer:
*
* Number of victim developers: X
*
* I wish the past developer had included such a notice.
*
* Long form: Unlike dns_rbt_findnode(), this function does not
* lend itself to be optimized using the hashtable:
*
* 1. In the subtree where the insertion occurs, this function
* needs to have the insertion point and the order where the
* lookup terminated (i.e., at the insertion point where left or
* right child is NULL). This cannot be determined from the
* hashtable, so at least in that subtree, a BST O(log N) lookup
* is necessary.
*
* 2. Our RBT nodes contain not only single labels but label
* sequences to optimize space usage. So at every level, we have
* to look for a match in the hashtable for all superdomains in
* the rest of the name we're searching. This is an O(N)
* operation at least, here N being the label size of name, each
* of which is a hashtable lookup involving dns_name_equal()
* comparisons.
*/
/*
* Create a copy of the name so the original name structure is
* not modified.
*/
add_name = dns_fixedname_initname(&fixedcopy);
INSIST(add_name != NULL);
dns_name_clone(name, add_name);
if (ISC_UNLIKELY(rbt->root == NULL)) {
result = create_node(rbt->mctx, add_name, &new_current);
if (result == ISC_R_SUCCESS) {
rbt->nodecount++;
new_current->is_root = 1;
UPPERNODE(new_current) = NULL;
rbt->root = new_current;
*nodep = new_current;
hash_node(rbt, new_current, name);
}
return (result);
}
level_count = 0;
prefix = dns_fixedname_initname(&fixedprefix);
suffix = dns_fixedname_initname(&fixedsuffix);
INSIST(prefix != NULL);
INSIST(suffix != NULL);
root = &rbt->root;
INSIST(IS_ROOT(*root));
parent = NULL;
current = NULL;
child = *root;
dns_name_init(&current_name, current_offsets);
new_name = dns_fixedname_initname(&fnewname);
nlabels = dns_name_countlabels(name);
hlabels = 0;
do {
current = child;
NODENAME(current, &current_name);
compared = dns_name_fullcompare(add_name, &current_name, &order,
&common_labels);
if (compared == dns_namereln_equal) {
*nodep = current;
result = ISC_R_EXISTS;
break;
}
if (compared == dns_namereln_none) {
if (order < 0) {
parent = current;
child = LEFT(current);
} else if (order > 0) {
parent = current;
child = RIGHT(current);
}
} else {
/*
* This name has some suffix in common with the
* name at the current node. If the name at
* the current node is shorter, that means the
* new name should be in a subtree. If the
* name at the current node is longer, that means
* the down pointer to this tree should point
* to a new tree that has the common suffix, and
* the non-common parts of these two names should
* start a new tree.
*/
hlabels += common_labels;
if (compared == dns_namereln_subdomain) {
/*
* All of the existing labels are in common,
* so the new name is in a subtree.
* Whack off the common labels for the
* not-in-common part to be searched for
* in the next level.
*/
dns_name_split(add_name, common_labels,
add_name, NULL);
/*
* Follow the down pointer (possibly NULL).
*/
root = &DOWN(current);
INSIST(*root == NULL ||
(IS_ROOT(*root) &&
PARENT(*root) == current));
parent = NULL;
child = DOWN(current);
INSIST(level_count < DNS_RBT_LEVELBLOCK);
level_count++;
} else {
/*
* The number of labels in common is fewer
* than the number of labels at the current
* node, so the current node must be adjusted
* to have just the common suffix, and a down
* pointer made to a new tree.
*/
INSIST(compared ==
dns_namereln_commonancestor ||
compared == dns_namereln_contains);
/*
* Ensure the number of levels in the tree
* does not exceed the number of logical
* levels allowed by DNSSEC.
*
* XXXDCL need a better error result?
*/
if (level_count >= DNS_RBT_LEVELBLOCK) {
result = ISC_R_NOSPACE;
break;
}
/*
* Split the name into two parts, a prefix
* which is the not-in-common parts of the
* two names and a suffix that is the common
* parts of them.
*/
dns_name_split(&current_name, common_labels,
prefix, suffix);
result = create_node(rbt->mctx, suffix,
&new_current);
if (result != ISC_R_SUCCESS) {
break;
}
/*
* Reproduce the tree attributes of the
* current node.
*/
new_current->is_root = current->is_root;
if (current->nsec == DNS_RBT_NSEC_HAS_NSEC) {
new_current->nsec = DNS_RBT_NSEC_NORMAL;
} else {
new_current->nsec = current->nsec;
}
PARENT(new_current) = PARENT(current);
LEFT(new_current) = LEFT(current);
RIGHT(new_current) = RIGHT(current);
COLOR(new_current) = COLOR(current);
/*
* Fix pointers that were to the current node.
*/
if (parent != NULL) {
if (LEFT(parent) == current) {
LEFT(parent) = new_current;
} else {
RIGHT(parent) = new_current;
}
}
if (LEFT(new_current) != NULL) {
PARENT(LEFT(new_current)) = new_current;
}
if (RIGHT(new_current) != NULL) {
PARENT(RIGHT(new_current)) =
new_current;
}
if (*root == current) {
*root = new_current;
}
NAMELEN(current) = prefix->length;
OFFSETLEN(current) = prefix->labels;
/*
* Set up the new root of the next level.
* By definition it will not be the top
* level tree, so clear DNS_NAMEATTR_ABSOLUTE.
*/
current->is_root = 1;
PARENT(current) = new_current;
DOWN(new_current) = current;
root = &DOWN(new_current);
UPPERNODE(new_current) = UPPERNODE(current);
UPPERNODE(current) = new_current;
INSIST(level_count < DNS_RBT_LEVELBLOCK);
level_count++;
LEFT(current) = NULL;
RIGHT(current) = NULL;
MAKE_BLACK(current);
ATTRS(current) &= ~DNS_NAMEATTR_ABSOLUTE;
rbt->nodecount++;
dns_name_getlabelsequence(name,
nlabels - hlabels,
hlabels, new_name);
hash_node(rbt, new_current, new_name);
if (common_labels ==
dns_name_countlabels(add_name)) {
/*
* The name has been added by pushing
* the not-in-common parts down to
* a new level.
*/
*nodep = new_current;
return (ISC_R_SUCCESS);
} else {
/*
* The current node has no data,
* because it is just a placeholder.
* Its data pointer is already NULL
* from create_node()), so there's
* nothing more to do to it.
*/
/*
* The not-in-common parts of the new
* name will be inserted into the new
* level following this loop (unless
* result != ISC_R_SUCCESS, which
* is tested after the loop ends).
*/
dns_name_split(add_name, common_labels,
add_name, NULL);
break;
}
}
}
} while (ISC_LIKELY(child != NULL));
if (ISC_LIKELY(result == ISC_R_SUCCESS)) {
result = create_node(rbt->mctx, add_name, &new_current);
}
if (ISC_LIKELY(result == ISC_R_SUCCESS)) {
if (*root == NULL) {
UPPERNODE(new_current) = current;
} else {
UPPERNODE(new_current) = PARENT(*root);
}
addonlevel(new_current, current, order, root);
rbt->nodecount++;
*nodep = new_current;
hash_node(rbt, new_current, name);
}
return (result);
}
/*
* Add a name to the tree of trees, associating it with some data.
*/
isc_result_t
dns_rbt_addname(dns_rbt_t *rbt, const dns_name_t *name, void *data) {
isc_result_t result;
dns_rbtnode_t *node;
REQUIRE(VALID_RBT(rbt));
REQUIRE(dns_name_isabsolute(name));
node = NULL;
result = dns_rbt_addnode(rbt, name, &node);
/*
* dns_rbt_addnode will report the node exists even when
* it does not have data associated with it, but the
* dns_rbt_*name functions all behave depending on whether
* there is data associated with a node.
*/
if (result == ISC_R_SUCCESS ||
(result == ISC_R_EXISTS && DATA(node) == NULL)) {
DATA(node) = data;
result = ISC_R_SUCCESS;
}
return (result);
}
/*
* Find the node for "name" in the tree of trees.
*/
isc_result_t
dns_rbt_findnode(dns_rbt_t *rbt, const dns_name_t *name, dns_name_t *foundname,
dns_rbtnode_t **node, dns_rbtnodechain_t *chain,
unsigned int options, dns_rbtfindcallback_t callback,
void *callback_arg) {
dns_rbtnode_t *current, *last_compared;
dns_rbtnodechain_t localchain;
dns_name_t *search_name, current_name, *callback_name;
dns_fixedname_t fixedcallbackname, fixedsearchname;
dns_namereln_t compared;
isc_result_t result, saved_result;
unsigned int common_labels;
unsigned int hlabels = 0;
int order;
REQUIRE(VALID_RBT(rbt));
REQUIRE(dns_name_isabsolute(name));
REQUIRE(node != NULL && *node == NULL);
REQUIRE((options & (DNS_RBTFIND_NOEXACT | DNS_RBTFIND_NOPREDECESSOR)) !=
(DNS_RBTFIND_NOEXACT | DNS_RBTFIND_NOPREDECESSOR));
/*
* If there is a chain it needs to appear to be in a sane state,
* otherwise a chain is still needed to generate foundname and
* callback_name.
*/
if (chain == NULL) {
options |= DNS_RBTFIND_NOPREDECESSOR;
chain = &localchain;
dns_rbtnodechain_init(chain);
} else {
dns_rbtnodechain_reset(chain);
}
if (ISC_UNLIKELY(rbt->root == NULL)) {
return (ISC_R_NOTFOUND);
}
/*
* Appease GCC about variables it incorrectly thinks are
* possibly used uninitialized.
*/
compared = dns_namereln_none;
last_compared = NULL;
order = 0;
callback_name = dns_fixedname_initname(&fixedcallbackname);
/*
* search_name is the name segment being sought in each tree level.
* By using a fixedname, the search_name will definitely have offsets
* for use by any splitting.
* By using dns_name_clone, no name data should be copied thanks to
* the lack of bitstring labels.
*/
search_name = dns_fixedname_initname(&fixedsearchname);
INSIST(search_name != NULL);
dns_name_clone(name, search_name);
dns_name_init(&current_name, NULL);
saved_result = ISC_R_SUCCESS;
current = rbt->root;
while (ISC_LIKELY(current != NULL)) {
NODENAME(current, &current_name);
compared = dns_name_fullcompare(search_name, &current_name,
&order, &common_labels);
/*
* last_compared is used as a shortcut to start (or
* continue rather) finding the stop-node of the search
* when hashing was used (see much below in this
* function).
*/
last_compared = current;
if (compared == dns_namereln_equal) {
break;
}
if (compared == dns_namereln_none) {
/*
* Here, current is pointing at a subtree root
* node. We try to find a matching node using
* the hashtable. We can get one of 3 results
* here: (a) we locate the matching node, (b) we
* find a node to which the current node has a
* subdomain relation, (c) we fail to find (a)
* or (b).
*/
dns_name_t hash_name;
dns_rbtnode_t *hnode;
dns_rbtnode_t *up_current;
unsigned int nlabels;
unsigned int tlabels = 1;
uint32_t hash;
/*
* The case of current not being a subtree root,
* that means a left or right pointer was
* followed, only happens when the algorithm
* fell through to the traditional binary search
* because of a bitstring label. Since we
* dropped the bitstring support, this should
* not happen.
*/
INSIST(IS_ROOT(current));
nlabels = dns_name_countlabels(search_name);
/*
* current is the root of the current level, so
* its parent is the same as its "up" pointer.
*/
up_current = PARENT(current);
dns_name_init(&hash_name, NULL);
hashagain:
/*
* Compute the hash over the full absolute
* name. Look for the smallest suffix match at
* this tree level (hlevel), and then at every
* iteration, look for the next smallest suffix
* match (add another subdomain label to the
* absolute name being hashed).
*/
dns_name_getlabelsequence(name, nlabels - tlabels,
hlabels + tlabels,
&hash_name);
hash = dns_name_fullhash(&hash_name, false);
dns_name_getlabelsequence(search_name,
nlabels - tlabels, tlabels,
&hash_name);
/*
* Walk all the nodes in the hash bucket pointed
* by the computed hash value.
*/
for (hnode = rbt->hashtable[hash_32(hash,
rbt->hashbits)];
hnode != NULL; hnode = hnode->hashnext)
{
dns_name_t hnode_name;
if (ISC_LIKELY(hash != HASHVAL(hnode))) {
continue;
}
/*
* This checks that the hashed label
* sequence being looked up is at the
* same tree level, so that we don't
* match a labelsequence from some other
* subdomain.
*/
if (ISC_LIKELY(get_upper_node(hnode) !=
up_current)) {
continue;
}
dns_name_init(&hnode_name, NULL);
NODENAME(hnode, &hnode_name);
if (ISC_LIKELY(dns_name_equal(&hnode_name,
&hash_name))) {
break;
}
}
if (hnode != NULL) {
current = hnode;
/*
* This is an optimization. If hashing found
* the right node, the next call to
* dns_name_fullcompare() would obviously
* return _equal or _subdomain. Determine
* which of those would be the case by
* checking if the full name was hashed. Then
* make it look like dns_name_fullcompare
* was called and jump to the right place.
*/
if (tlabels == nlabels) {
compared = dns_namereln_equal;
break;
} else {
common_labels = tlabels;
compared = dns_namereln_subdomain;
goto subdomain;
}
}
if (tlabels++ < nlabels) {
goto hashagain;
}
/*
* All of the labels have been tried against the hash
* table. Since we dropped the support of bitstring
* labels, the name isn't in the table.
*/
current = NULL;
continue;
} else {
/*
* The names have some common suffix labels.
*
* If the number in common are equal in length to
* the current node's name length, then follow the
* down pointer and search in the new tree.
*/
if (compared == dns_namereln_subdomain) {
subdomain:
/*
* Whack off the current node's common parts
* for the name to search in the next level.
*/
dns_name_split(search_name, common_labels,
search_name, NULL);
hlabels += common_labels;
/*
* This might be the closest enclosing name.
*/
if (WANTEMPTYDATA_OR_DATA(options, current)) {
*node = current;
}
/*
* Point the chain to the next level. This
* needs to be done before 'current' is pointed
* there because the callback in the next
* block of code needs the current 'current',
* but in the event the callback requests that
* the search be stopped then the
* DNS_R_PARTIALMATCH code at the end of this
* function needs the chain pointed to the
* next level.
*/
ADD_LEVEL(chain, current);
/*
* The caller may want to interrupt the
* downward search when certain special nodes
* are traversed. If this is a special node,
* the callback is used to learn what the
* caller wants to do.
*/
if (callback != NULL && FINDCALLBACK(current)) {
result = chain_name(
chain, callback_name, false);
if (result != ISC_R_SUCCESS) {
dns_rbtnodechain_reset(chain);
return (result);
}
result = (callback)(current,
callback_name,
callback_arg);
if (result != DNS_R_CONTINUE) {
saved_result = result;
/*
* Treat this node as if it
* had no down pointer.
*/
current = NULL;
break;
}
}
/*
* Finally, head to the next tree level.
*/
current = DOWN(current);
} else {
/*
* Though there are labels in common, the
* entire name at this node is not common
* with the search name so the search
* name does not exist in the tree.
*/
INSIST(compared ==
dns_namereln_commonancestor ||
compared == dns_namereln_contains);
current = NULL;
}
}
}
/*
* If current is not NULL, NOEXACT is not disallowing exact matches,
* and either the node has data or an empty node is ok, return
* ISC_R_SUCCESS to indicate an exact match.
*/
if (current != NULL && (options & DNS_RBTFIND_NOEXACT) == 0 &&
WANTEMPTYDATA_OR_DATA(options, current))
{
/*
* Found an exact match.
*/
chain->end = current;
chain->level_matches = chain->level_count;
if (foundname != NULL) {
result = chain_name(chain, foundname, true);
} else {
result = ISC_R_SUCCESS;
}
if (result == ISC_R_SUCCESS) {
*node = current;
result = saved_result;
} else {
*node = NULL;
}
} else {
/*
* Did not find an exact match (or did not want one).
*/
if (*node != NULL) {
/*
* ... but found a partially matching superdomain.
* Unwind the chain to the partial match node
* to set level_matches to the level above the node,
* and then to derive the name.
*
* chain->level_count is guaranteed to be at least 1
* here because by definition of finding a superdomain,
* the chain is pointed to at least the first subtree.
*/
chain->level_matches = chain->level_count - 1;
while (chain->levels[chain->level_matches] != *node) {
INSIST(chain->level_matches > 0);
chain->level_matches--;
}
if (foundname != NULL) {
unsigned int saved_count = chain->level_count;
chain->level_count = chain->level_matches + 1;
result = chain_name(chain, foundname, false);
chain->level_count = saved_count;
} else {
result = ISC_R_SUCCESS;
}
if (result == ISC_R_SUCCESS) {
result = DNS_R_PARTIALMATCH;
}
} else {
result = ISC_R_NOTFOUND;
}
if (current != NULL) {
/*
* There was an exact match but either
* DNS_RBTFIND_NOEXACT was set, or
* DNS_RBTFIND_EMPTYDATA was set and the node had no
* data. A policy decision was made to set the
* chain to the exact match, but this is subject
* to change if it becomes apparent that something
* else would be more useful. It is important that
* this case is handled here, because the predecessor
* setting code below assumes the match was not exact.
*/
INSIST(((options & DNS_RBTFIND_NOEXACT) != 0) ||
((options & DNS_RBTFIND_EMPTYDATA) == 0 &&
DATA(current) == NULL));
chain->end = current;
} else if ((options & DNS_RBTFIND_NOPREDECESSOR) != 0) {
/*
* Ensure the chain points nowhere.
*/
chain->end = NULL;
} else {
/*
* Since there was no exact match, the chain argument
* needs to be pointed at the DNSSEC predecessor of
* the search name.
*/
if (compared == dns_namereln_subdomain) {
/*
* Attempted to follow a down pointer that was
* NULL, which means the searched for name was
* a subdomain of a terminal name in the tree.
* Since there are no existing subdomains to
* order against, the terminal name is the
* predecessor.
*/
INSIST(chain->level_count > 0);
INSIST(chain->level_matches <
chain->level_count);
chain->end =
chain->levels[--chain->level_count];
} else {
isc_result_t result2;
/*
* Point current to the node that stopped
* the search.
*
* With the hashing modification that has been
* added to the algorithm, the stop node of a
* standard binary search is not known. So it
* has to be found. There is probably a more
* clever way of doing this.
*
* The assignment of current to NULL when
* the relationship is *not* dns_namereln_none,
* even though it later gets set to the same
* last_compared anyway, is simply to not push
* the while loop in one more level of
* indentation.
*/
if (compared == dns_namereln_none) {
current = last_compared;
} else {
current = NULL;
}
while (current != NULL) {
NODENAME(current, &current_name);
compared = dns_name_fullcompare(
search_name, &current_name,
&order, &common_labels);
POST(compared);
last_compared = current;
/*
* Standard binary search movement.
*/
if (order < 0) {
current = LEFT(current);
} else {
current = RIGHT(current);
}
}
current = last_compared;
/*
* Reached a point within a level tree that
* positively indicates the name is not
* present, but the stop node could be either
* less than the desired name (order > 0) or
* greater than the desired name (order < 0).
*
* If the stop node is less, it is not
* necessarily the predecessor. If the stop
* node has a down pointer, then the real
* predecessor is at the end of a level below
* (not necessarily the next level).
* Move down levels until the rightmost node
* does not have a down pointer.
*
* When the stop node is greater, it is
* the successor. All the logic for finding
* the predecessor is handily encapsulated
* in dns_rbtnodechain_prev. In the event
* that the search name is less than anything
* else in the tree, the chain is reset.
* XXX DCL What is the best way for the caller
* to know that the search name has
* no predecessor?
*/
if (order > 0) {
if (DOWN(current) != NULL) {
ADD_LEVEL(chain, current);
result2 = move_chain_to_last(
chain, DOWN(current));
if (result2 != ISC_R_SUCCESS) {
result = result2;
}
} else {
/*
* Ah, the pure and simple
* case. The stop node is the
* predecessor.
*/
chain->end = current;
}
} else {
INSIST(order < 0);
chain->end = current;
result2 = dns_rbtnodechain_prev(
chain, NULL, NULL);
if (result2 == ISC_R_SUCCESS ||
result2 == DNS_R_NEWORIGIN) {
/* Nothing. */
} else if (result2 == ISC_R_NOMORE) {
/*
* There is no predecessor.
*/
dns_rbtnodechain_reset(chain);
} else {
result = result2;
}
}
}
}
}
ENSURE(*node == NULL || DNS_RBTNODE_VALID(*node));
return (result);
}
/*
* Get the data pointer associated with 'name'.
*/
isc_result_t
dns_rbt_findname(dns_rbt_t *rbt, const dns_name_t *name, unsigned int options,
dns_name_t *foundname, void **data) {
dns_rbtnode_t *node = NULL;
isc_result_t result;
REQUIRE(data != NULL && *data == NULL);
result = dns_rbt_findnode(rbt, name, foundname, &node, NULL, options,
NULL, NULL);
if (node != NULL && WANTEMPTYDATA_OR_DATA(options, node)) {
*data = DATA(node);
} else {
result = ISC_R_NOTFOUND;
}
return (result);
}
/*
* Delete a name from the tree of trees.
*/
isc_result_t
dns_rbt_deletename(dns_rbt_t *rbt, const dns_name_t *name, bool recurse) {
dns_rbtnode_t *node = NULL;
isc_result_t result;
REQUIRE(VALID_RBT(rbt));
REQUIRE(dns_name_isabsolute(name));
/*
* First, find the node.
*
* When searching, the name might not have an exact match:
* consider a.b.a.com, b.b.a.com and c.b.a.com as the only
* elements of a tree, which would make layer 1 a single
* node tree of "b.a.com" and layer 2 a three node tree of
* a, b, and c. Deleting a.com would find only a partial depth
* match in the first layer. Should it be a requirement that
* that the name to be deleted have data? For now, it is.
*
* ->dirty, ->locknum and ->references are ignored; they are
* solely the province of rbtdb.c.
*/
result = dns_rbt_findnode(rbt, name, NULL, &node, NULL,
DNS_RBTFIND_NOOPTIONS, NULL, NULL);
if (result == ISC_R_SUCCESS) {
if (DATA(node) != NULL) {
result = dns_rbt_deletenode(rbt, node, recurse);
} else {
result = ISC_R_NOTFOUND;
}
} else if (result == DNS_R_PARTIALMATCH) {
result = ISC_R_NOTFOUND;
}
return (result);
}
/*
* Remove a node from the tree of trees.
*
* NOTE WELL: deletion is *not* symmetric with addition; that is, reversing
* a sequence of additions to be deletions will not generally get the
* tree back to the state it started in. For example, if the addition
* of "b.c" caused the node "a.b.c" to be split, pushing "a" to its own level,
* then the subsequent deletion of "b.c" will not cause "a" to be pulled up,
* restoring "a.b.c". The RBT *used* to do this kind of rejoining, but it
* turned out to be a bad idea because it could corrupt an active nodechain
* that had "b.c" as one of its levels -- and the RBT has no idea what
* nodechains are in use by callers, so it can't even *try* to helpfully
* fix them up (which would probably be doomed to failure anyway).
*
* Similarly, it is possible to leave the tree in a state where a supposedly
* deleted node still exists. The first case of this is obvious; take
* the tree which has "b.c" on one level, pointing to "a". Now deleted "b.c".
* It was just established in the previous paragraph why we can't pull "a"
* back up to its parent level. But what happens when "a" then gets deleted?
* "b.c" is left hanging around without data or children. This condition
* is actually pretty easy to detect, but ... should it really be removed?
* Is a chain pointing to it? An iterator? Who knows! (Note that the
* references structure member cannot be looked at because it is private to
* rbtdb.) This is ugly and makes me unhappy, but after hours of trying to
* make it more aesthetically proper and getting nowhere, this is the way it
* is going to stay until such time as it proves to be a *real* problem.
*
* Finally, for reference, note that the original routine that did node
* joining was called join_nodes(). It has been excised, living now only
* in the CVS history, but comments have been left behind that point to it just
* in case someone wants to muck with this some more.
*
* The one positive aspect of all of this is that joining used to have a
* case where it might fail. Without trying to join, now this function always
* succeeds. It still returns isc_result_t, though, so the API wouldn't change.
*/
isc_result_t
dns_rbt_deletenode(dns_rbt_t *rbt, dns_rbtnode_t *node, bool recurse) {
dns_rbtnode_t *parent;
REQUIRE(VALID_RBT(rbt));
REQUIRE(DNS_RBTNODE_VALID(node));
INSIST(rbt->nodecount != 0);
if (DOWN(node) != NULL) {
if (recurse) {
PARENT(DOWN(node)) = NULL;
deletetreeflat(rbt, 0, true, &DOWN(node));
} else {
if (DATA(node) != NULL && rbt->data_deleter != NULL) {
rbt->data_deleter(DATA(node), rbt->deleter_arg);
}
DATA(node) = NULL;
/*
* Since there is at least one node below this one and
* no recursion was requested, the deletion is
* complete. The down node from this node might be all
* by itself on a single level, so join_nodes() could
* be used to collapse the tree (with all the caveats
* of the comment at the start of this function).
* But join_nodes() function has now been removed.
*/
return (ISC_R_SUCCESS);
}
}
/*
* Note the node that points to the level of the node
* that is being deleted. If the deleted node is the
* top level, parent will be set to NULL.
*/
parent = get_upper_node(node);
/*
* This node now has no down pointer, so now it needs
* to be removed from this level.
*/
deletefromlevel(node, parent == NULL ? &rbt->root : &DOWN(parent));
if (DATA(node) != NULL && rbt->data_deleter != NULL) {
rbt->data_deleter(DATA(node), rbt->deleter_arg);
}
unhash_node(rbt, node);
#if DNS_RBT_USEMAGIC
node->magic = 0;
#endif /* if DNS_RBT_USEMAGIC */
isc_refcount_destroy(&node->references);
freenode(rbt, &node);
/*
* This function never fails.
*/
return (ISC_R_SUCCESS);
}
void
dns_rbt_namefromnode(dns_rbtnode_t *node, dns_name_t *name) {
REQUIRE(DNS_RBTNODE_VALID(node));
REQUIRE(name != NULL);
REQUIRE(name->offsets == NULL);
NODENAME(node, name);
}
isc_result_t
dns_rbt_fullnamefromnode(dns_rbtnode_t *node, dns_name_t *name) {
dns_name_t current;
isc_result_t result;
REQUIRE(DNS_RBTNODE_VALID(node));
REQUIRE(name != NULL);
REQUIRE(name->buffer != NULL);
dns_name_init(&current, NULL);
dns_name_reset(name);
do {
INSIST(node != NULL);
NODENAME(node, &current);
result = dns_name_concatenate(name, &current, name, NULL);
if (result != ISC_R_SUCCESS) {
break;
}
node = get_upper_node(node);
} while (!dns_name_isabsolute(name));
return (result);
}
char *
dns_rbt_formatnodename(dns_rbtnode_t *node, char *printname,
unsigned int size) {
dns_fixedname_t fixedname;
dns_name_t *name;
isc_result_t result;
REQUIRE(DNS_RBTNODE_VALID(node));
REQUIRE(printname != NULL);
name = dns_fixedname_initname(&fixedname);
result = dns_rbt_fullnamefromnode(node, name);
if (result == ISC_R_SUCCESS) {
dns_name_format(name, printname, size);
} else {
snprintf(printname, size, "<error building name: %s>",
dns_result_totext(result));
}
return (printname);
}
static isc_result_t
create_node(isc_mem_t *mctx, const dns_name_t *name, dns_rbtnode_t **nodep) {
dns_rbtnode_t *node;
isc_region_t region;
unsigned int labels;
size_t nodelen;
REQUIRE(name->offsets != NULL);
dns_name_toregion(name, &region);
labels = dns_name_countlabels(name);
ENSURE(labels > 0);
/*
* Allocate space for the node structure, the name, and the offsets.
*/
nodelen = sizeof(dns_rbtnode_t) + region.length + labels + 1;
node = isc_mem_get(mctx, nodelen);
memset(node, 0, nodelen);
node->is_root = 0;
PARENT(node) = NULL;
RIGHT(node) = NULL;
LEFT(node) = NULL;
DOWN(node) = NULL;
DATA(node) = NULL;
node->is_mmapped = 0;
node->down_is_relative = 0;
node->left_is_relative = 0;
node->right_is_relative = 0;
node->parent_is_relative = 0;
node->data_is_relative = 0;
node->rpz = 0;
HASHNEXT(node) = NULL;
HASHVAL(node) = 0;
ISC_LINK_INIT(node, deadlink);
LOCKNUM(node) = 0;
WILD(node) = 0;
DIRTY(node) = 0;
isc_refcount_init(&node->references, 0);
node->find_callback = 0;
node->nsec = DNS_RBT_NSEC_NORMAL;
MAKE_BLACK(node);
/*
* The following is stored to make reconstructing a name from the
* stored value in the node easy: the length of the name, the number
* of labels, whether the name is absolute or not, the name itself,
* and the name's offsets table.
*
* XXX RTH
* The offsets table could be made smaller by eliminating the
* first offset, which is always 0. This requires changes to
* lib/dns/name.c.
*
* Note: OLDOFFSETLEN *must* be assigned *after* OLDNAMELEN is assigned
* as it uses OLDNAMELEN.
*/
OLDNAMELEN(node) = NAMELEN(node) = region.length;
OLDOFFSETLEN(node) = OFFSETLEN(node) = labels;
ATTRS(node) = name->attributes;
memmove(NAME(node), region.base, region.length);
memmove(OFFSETS(node), name->offsets, labels);
#if DNS_RBT_USEMAGIC
node->magic = DNS_RBTNODE_MAGIC;
#endif /* if DNS_RBT_USEMAGIC */
*nodep = node;
return (ISC_R_SUCCESS);
}
/*
* Add a node to the hash table
*/
static inline void
hash_add_node(dns_rbt_t *rbt, dns_rbtnode_t *node, const dns_name_t *name) {
uint32_t hash;
REQUIRE(name != NULL);
HASHVAL(node) = dns_name_fullhash(name, false);
hash = hash_32(HASHVAL(node), rbt->hashbits);
HASHNEXT(node) = rbt->hashtable[hash];
rbt->hashtable[hash] = node;
}
/*
* Initialize hash table
*/
static isc_result_t
inithash(dns_rbt_t *rbt) {
size_t size;
rbt->hashbits = RBT_HASH_MIN_BITS;
size = HASHSIZE(rbt->hashbits) * sizeof(dns_rbtnode_t *);
rbt->hashtable = isc_mem_get(rbt->mctx, size);
memset(rbt->hashtable, 0, size);
return (ISC_R_SUCCESS);
}
static uint32_t
rehash_bits(dns_rbt_t *rbt, size_t newcount) {
uint32_t newbits = rbt->hashbits;
while (newcount >= HASHSIZE(newbits) && newbits < rbt->maxhashbits) {
newbits += 1;
}
return (newbits);
}
/*
* Rebuild the hashtable to reduce the load factor
*/
static void
rehash(dns_rbt_t *rbt, uint32_t newbits) {
uint32_t oldbits;
size_t oldsize;
dns_rbtnode_t **oldtable;
size_t newsize;
REQUIRE(rbt->hashbits <= rbt->maxhashbits);
REQUIRE(newbits <= rbt->maxhashbits);
oldbits = rbt->hashbits;
oldsize = HASHSIZE(oldbits);
oldtable = rbt->hashtable;
rbt->hashbits = newbits;
newsize = HASHSIZE(rbt->hashbits);
rbt->hashtable = isc_mem_get(rbt->mctx,
newsize * sizeof(dns_rbtnode_t *));
memset(rbt->hashtable, 0, newsize * sizeof(dns_rbtnode_t *));
for (size_t i = 0; i < oldsize; i++) {
dns_rbtnode_t *node;
dns_rbtnode_t *nextnode;
for (node = oldtable[i]; node != NULL; node = nextnode) {
uint32_t hash = hash_32(HASHVAL(node), rbt->hashbits);
nextnode = HASHNEXT(node);
HASHNEXT(node) = rbt->hashtable[hash];
rbt->hashtable[hash] = node;
}
}
isc_mem_put(rbt->mctx, oldtable, oldsize * sizeof(dns_rbtnode_t *));
}
static void
maybe_rehash(dns_rbt_t *rbt, size_t newcount) {
uint32_t newbits = rehash_bits(rbt, newcount);
if (rbt->hashbits < newbits && newbits <= rbt->maxhashbits) {
rehash(rbt, newbits);
}
}
/*
* Add a node to the hash table. Rehash the hashtable if the node count
* rises above a critical level.
*/
static inline void
hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node, const dns_name_t *name) {
REQUIRE(DNS_RBTNODE_VALID(node));
if (rbt->nodecount >= (HASHSIZE(rbt->hashbits) * RBT_HASH_OVERCOMMIT)) {
maybe_rehash(rbt, rbt->nodecount);
}
hash_add_node(rbt, node, name);
}
/*
* Remove a node from the hash table
*/
static inline void
unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node) {
uint32_t bucket;
dns_rbtnode_t *bucket_node;
REQUIRE(DNS_RBTNODE_VALID(node));
bucket = hash_32(HASHVAL(node), rbt->hashbits);
bucket_node = rbt->hashtable[bucket];
if (bucket_node == node) {
rbt->hashtable[bucket] = HASHNEXT(node);
} else {
while (HASHNEXT(bucket_node) != node) {
INSIST(HASHNEXT(bucket_node) != NULL);
bucket_node = HASHNEXT(bucket_node);
}
HASHNEXT(bucket_node) = HASHNEXT(node);
}
}
static inline void
rotate_left(dns_rbtnode_t *node, dns_rbtnode_t **rootp) {
dns_rbtnode_t *child;
REQUIRE(DNS_RBTNODE_VALID(node));
REQUIRE(rootp != NULL);
child = RIGHT(node);
INSIST(child != NULL);
RIGHT(node) = LEFT(child);
if (LEFT(child) != NULL) {
PARENT(LEFT(child)) = node;
}
LEFT(child) = node;
PARENT(child) = PARENT(node);
if (IS_ROOT(node)) {
*rootp = child;
child->is_root = 1;
node->is_root = 0;
} else {
if (LEFT(PARENT(node)) == node) {
LEFT(PARENT(node)) = child;
} else {
RIGHT(PARENT(node)) = child;
}
}
PARENT(node) = child;
}
static inline void
rotate_right(dns_rbtnode_t *node, dns_rbtnode_t **rootp) {
dns_rbtnode_t *child;
REQUIRE(DNS_RBTNODE_VALID(node));
REQUIRE(rootp != NULL);
child = LEFT(node);
INSIST(child != NULL);
LEFT(node) = RIGHT(child);
if (RIGHT(child) != NULL) {
PARENT(RIGHT(child)) = node;
}
RIGHT(child) = node;
PARENT(child) = PARENT(node);
if (IS_ROOT(node)) {
*rootp = child;
child->is_root = 1;
node->is_root = 0;
} else {
if (LEFT(PARENT(node)) == node) {
LEFT(PARENT(node)) = child;
} else {
RIGHT(PARENT(node)) = child;
}
}
PARENT(node) = child;
}
/*
* This is the real workhorse of the insertion code, because it does the
* true red/black tree on a single level.
*/
static void
addonlevel(dns_rbtnode_t *node, dns_rbtnode_t *current, int order,
dns_rbtnode_t **rootp) {
dns_rbtnode_t *child, *root, *parent, *grandparent;
dns_name_t add_name, current_name;
dns_offsets_t add_offsets, current_offsets;
REQUIRE(rootp != NULL);
REQUIRE(DNS_RBTNODE_VALID(node) && LEFT(node) == NULL &&
RIGHT(node) == NULL);
REQUIRE(current != NULL);
root = *rootp;
if (root == NULL) {
/*
* First node of a level.
*/
MAKE_BLACK(node);
node->is_root = 1;
PARENT(node) = current;
*rootp = node;
return;
}
child = root;
POST(child);
dns_name_init(&add_name, add_offsets);
NODENAME(node, &add_name);
dns_name_init(&current_name, current_offsets);
NODENAME(current, &current_name);
if (order < 0) {
INSIST(LEFT(current) == NULL);
LEFT(current) = node;
} else {
INSIST(RIGHT(current) == NULL);
RIGHT(current) = node;
}
INSIST(PARENT(node) == NULL);
PARENT(node) = current;
MAKE_RED(node);
while (node != root && IS_RED(PARENT(node))) {
/*
* XXXDCL could do away with separate parent and grandparent
* variables. They are vestiges of the days before parent
* pointers. However, they make the code a little clearer.
*/
parent = PARENT(node);
grandparent = PARENT(parent);
if (parent == LEFT(grandparent)) {
child = RIGHT(grandparent);
if (child != NULL && IS_RED(child)) {
MAKE_BLACK(parent);
MAKE_BLACK(child);
MAKE_RED(grandparent);
node = grandparent;
} else {
if (node == RIGHT(parent)) {
rotate_left(parent, &root);
node = parent;
parent = PARENT(node);
grandparent = PARENT(parent);
}
MAKE_BLACK(parent);
MAKE_RED(grandparent);
rotate_right(grandparent, &root);
}
} else {
child = LEFT(grandparent);
if (child != NULL && IS_RED(child)) {
MAKE_BLACK(parent);
MAKE_BLACK(child);
MAKE_RED(grandparent);
node = grandparent;
} else {
if (node == LEFT(parent)) {
rotate_right(parent, &root);
node = parent;
parent = PARENT(node);
grandparent = PARENT(parent);
}
MAKE_BLACK(parent);
MAKE_RED(grandparent);
rotate_left(grandparent, &root);
}
}
}
MAKE_BLACK(root);
ENSURE(IS_ROOT(root));
*rootp = root;
return;
}
/*
* This is the real workhorse of the deletion code, because it does the
* true red/black tree on a single level.
*/
static void
deletefromlevel(dns_rbtnode_t *item, dns_rbtnode_t **rootp) {
dns_rbtnode_t *child, *sibling, *parent;
dns_rbtnode_t *successor;
REQUIRE(item != NULL);
/*
* Verify that the parent history is (apparently) correct.
*/
INSIST((IS_ROOT(item) && *rootp == item) ||
(!IS_ROOT(item) &&
(LEFT(PARENT(item)) == item || RIGHT(PARENT(item)) == item)));
child = NULL;
if (LEFT(item) == NULL) {
if (RIGHT(item) == NULL) {
if (IS_ROOT(item)) {
/*
* This is the only item in the tree.
*/
*rootp = NULL;
return;
}
} else {
/*
* This node has one child, on the right.
*/
child = RIGHT(item);
}
} else if (RIGHT(item) == NULL) {
/*
* This node has one child, on the left.
*/
child = LEFT(item);
} else {
dns_rbtnode_t *saved_parent, *saved_right;
int saved_color;
/*
* This node has two children, so it cannot be directly
* deleted. Find its immediate in-order successor and
* move it to this location, then do the deletion at the
* old site of the successor.
*/
successor = RIGHT(item);
while (LEFT(successor) != NULL) {
successor = LEFT(successor);
}
/*
* The successor cannot possibly have a left child;
* if there is any child, it is on the right.
*/
if (RIGHT(successor) != NULL) {
child = RIGHT(successor);
}
/*
* Swap the two nodes; it would be simpler to just replace
* the value being deleted with that of the successor,
* but this rigamarole is done so the caller has complete
* control over the pointers (and memory allocation) of
* all of nodes. If just the key value were removed from
* the tree, the pointer to the node would be unchanged.
*/
/*
* First, put the successor in the tree location of the
* node to be deleted. Save its existing tree pointer
* information, which will be needed when linking up
* delete to the successor's old location.
*/
saved_parent = PARENT(successor);
saved_right = RIGHT(successor);
saved_color = COLOR(successor);
if (IS_ROOT(item)) {
*rootp = successor;
successor->is_root = true;
item->is_root = false;
} else if (LEFT(PARENT(item)) == item) {
LEFT(PARENT(item)) = successor;
} else {
RIGHT(PARENT(item)) = successor;
}
PARENT(successor) = PARENT(item);
LEFT(successor) = LEFT(item);
RIGHT(successor) = RIGHT(item);
COLOR(successor) = COLOR(item);
if (LEFT(successor) != NULL) {
PARENT(LEFT(successor)) = successor;
}
if (RIGHT(successor) != successor) {
PARENT(RIGHT(successor)) = successor;
}
/*
* Now relink the node to be deleted into the
* successor's previous tree location.
*/
INSIST(!IS_ROOT(item));
if (saved_parent == item) {
/*
* Node being deleted was successor's parent.
*/
RIGHT(successor) = item;
PARENT(item) = successor;
} else {
LEFT(saved_parent) = item;
PARENT(item) = saved_parent;
}
/*
* Original location of successor node has no left.
*/
LEFT(item) = NULL;
RIGHT(item) = saved_right;
COLOR(item) = saved_color;
}
/*
* Remove the node by removing the links from its parent.
*/
if (!IS_ROOT(item)) {
if (LEFT(PARENT(item)) == item) {
LEFT(PARENT(item)) = child;
} else {
RIGHT(PARENT(item)) = child;
}
if (child != NULL) {
PARENT(child) = PARENT(item);
}
} else {
/*
* This is the root being deleted, and at this point
* it is known to have just one child.
*/
*rootp = child;
child->is_root = 1;
PARENT(child) = PARENT(item);
}
/*
* Fix color violations.
*/
if (IS_BLACK(item)) {
/* cppcheck-suppress nullPointerRedundantCheck symbolName=item
*/
parent = PARENT(item);
while (child != *rootp && IS_BLACK(child)) {
INSIST(child == NULL || !IS_ROOT(child));
if (LEFT(parent) == child) {
sibling = RIGHT(parent);
if (IS_RED(sibling)) {
MAKE_BLACK(sibling);
MAKE_RED(parent);
rotate_left(parent, rootp);
sibling = RIGHT(parent);
}
INSIST(sibling != NULL);
/* cppcheck-suppress nullPointerRedundantCheck
* symbolName=sibling */
if (IS_BLACK(LEFT(sibling)) &&
IS_BLACK(RIGHT(sibling))) {
MAKE_RED(sibling);
child = parent;
} else {
if (IS_BLACK(RIGHT(sibling))) {
MAKE_BLACK(LEFT(sibling));
MAKE_RED(sibling);
rotate_right(sibling, rootp);
sibling = RIGHT(parent);
}
COLOR(sibling) = COLOR(parent);
MAKE_BLACK(parent);
INSIST(RIGHT(sibling) != NULL);
MAKE_BLACK(RIGHT(sibling));
rotate_left(parent, rootp);
child = *rootp;
}
} else {
/*
* Child is parent's right child.
* Everything is done the same as above,
* except mirrored.
*/
sibling = LEFT(parent);
if (IS_RED(sibling)) {
MAKE_BLACK(sibling);
MAKE_RED(parent);
rotate_right(parent, rootp);
sibling = LEFT(parent);
}
INSIST(sibling != NULL);
/* cppcheck-suppress nullPointerRedundantCheck
* symbolName=sibling */
if (IS_BLACK(LEFT(sibling)) &&
IS_BLACK(RIGHT(sibling))) {
MAKE_RED(sibling);
child = parent;
} else {
if (IS_BLACK(LEFT(sibling))) {
MAKE_BLACK(RIGHT(sibling));
MAKE_RED(sibling);
rotate_left(sibling, rootp);
sibling = LEFT(parent);
}
COLOR(sibling) = COLOR(parent);
MAKE_BLACK(parent);
INSIST(LEFT(sibling) != NULL);
MAKE_BLACK(LEFT(sibling));
rotate_right(parent, rootp);
child = *rootp;
}
}
parent = PARENT(child);
}
if (IS_RED(child)) {
MAKE_BLACK(child);
}
}
}
static void
freenode(dns_rbt_t *rbt, dns_rbtnode_t **nodep) {
dns_rbtnode_t *node = *nodep;
*nodep = NULL;
if (node->is_mmapped == 0) {
isc_mem_put(rbt->mctx, node, NODE_SIZE(node));
}
rbt->nodecount--;
}
static void
deletetreeflat(dns_rbt_t *rbt, unsigned int quantum, bool unhash,
dns_rbtnode_t **nodep) {
dns_rbtnode_t *root = *nodep;
while (root != NULL) {
/*
* If there is a left, right or down node, walk into it
* and iterate.
*/
if (LEFT(root) != NULL) {
dns_rbtnode_t *node = root;
root = LEFT(root);
LEFT(node) = NULL;
} else if (RIGHT(root) != NULL) {
dns_rbtnode_t *node = root;
root = RIGHT(root);
RIGHT(node) = NULL;
} else if (DOWN(root) != NULL) {
dns_rbtnode_t *node = root;
root = DOWN(root);
DOWN(node) = NULL;
} else {
/*
* There are no left, right or down nodes, so we
* can free this one and go back to its parent.
*/
dns_rbtnode_t *node = root;
root = PARENT(root);
if (rbt->data_deleter != NULL && DATA(node) != NULL) {
rbt->data_deleter(DATA(node), rbt->deleter_arg);
}
if (unhash) {
unhash_node(rbt, node);
}
/*
* Note: we don't call unhash_node() here as we
* are destroying the complete RBT tree.
*/
#if DNS_RBT_USEMAGIC
node->magic = 0;
#endif /* if DNS_RBT_USEMAGIC */
freenode(rbt, &node);
if (quantum != 0 && --quantum == 0) {
break;
}
}
}
*nodep = root;
}
static size_t
getheight_helper(dns_rbtnode_t *node) {
size_t dl, dr;
size_t this_height, down_height;
if (node == NULL) {
return (0);
}
dl = getheight_helper(LEFT(node));
dr = getheight_helper(RIGHT(node));
this_height = ISC_MAX(dl + 1, dr + 1);
down_height = getheight_helper(DOWN(node));
return (ISC_MAX(this_height, down_height));
}
size_t
dns__rbt_getheight(dns_rbt_t *rbt) {
return (getheight_helper(rbt->root));
}
static bool
check_properties_helper(dns_rbtnode_t *node) {
if (node == NULL) {
return (true);
}
if (IS_RED(node)) {
/* Root nodes must be BLACK. */
if (IS_ROOT(node)) {
return (false);
}
/* Both children of RED nodes must be BLACK. */
if (IS_RED(LEFT(node)) || IS_RED(RIGHT(node))) {
return (false);
}
}
/* cppcheck-suppress nullPointerRedundantCheck symbolName=node */
if ((DOWN(node) != NULL) && (!IS_ROOT(DOWN(node)))) {
return (false);
}
if (IS_ROOT(node)) {
if ((PARENT(node) != NULL) && (DOWN(PARENT(node)) != node)) {
return (false);
}
if (get_upper_node(node) != PARENT(node)) {
return (false);
}
}
/* If node is assigned to the down_ pointer of its parent, it is
* a subtree root and must have the flag set.
*/
if (((!PARENT(node)) || (DOWN(PARENT(node)) == node)) &&
(!IS_ROOT(node))) {
return (false);
}
/* Repeat tests with this node's children. */
return (check_properties_helper(LEFT(node)) &&
check_properties_helper(RIGHT(node)) &&
check_properties_helper(DOWN(node)));
}
static bool
check_black_distance_helper(dns_rbtnode_t *node, size_t *distance) {
size_t dl, dr, dd;
if (node == NULL) {
*distance = 1;
return (true);
}
/* cppcheck-suppress nullPointerRedundantCheck symbolName=node */
if (!check_black_distance_helper(LEFT(node), &dl)) {
return (false);
}
/* cppcheck-suppress nullPointerRedundantCheck symbolName=node */
if (!check_black_distance_helper(RIGHT(node), &dr)) {
return (false);
}
/* cppcheck-suppress nullPointerRedundantCheck symbolName=node */
if (!check_black_distance_helper(DOWN(node), &dd)) {
return (false);
}
/* Left and right side black node counts must match. */
if (dl != dr) {
return (false);
}
if (IS_BLACK(node)) {
dl++;
}
*distance = dl;
return (true);
}
bool
dns__rbt_checkproperties(dns_rbt_t *rbt) {
size_t dd;
if (!check_properties_helper(rbt->root)) {
return (false);
}
/* Path from a given node to all its leaves must contain the
* same number of BLACK child nodes. This is done separately
* here instead of inside check_properties_helper() as
* it would take (n log n) complexity otherwise.
*/
return (check_black_distance_helper(rbt->root, &dd));
}
static void
dns_rbt_indent(FILE *f, int depth) {
int i;
fprintf(f, "%4d ", depth);
for (i = 0; i < depth; i++) {
fprintf(f, "- ");
}
}
void
dns_rbt_printnodeinfo(dns_rbtnode_t *n, FILE *f) {
if (n == NULL) {
fprintf(f, "Null node\n");
return;
}
fprintf(f, "Node info for nodename: ");
printnodename(n, true, f);
fprintf(f, "\n");
fprintf(f, "n = %p\n", n);
fprintf(f, "Relative pointers: %s%s%s%s%s\n",
(n->parent_is_relative == 1 ? " P" : ""),
(n->right_is_relative == 1 ? " R" : ""),
(n->left_is_relative == 1 ? " L" : ""),
(n->down_is_relative == 1 ? " D" : ""),
(n->data_is_relative == 1 ? " T" : ""));
fprintf(f, "node lock address = %u\n", n->locknum);
fprintf(f, "Parent: %p\n", n->parent);
fprintf(f, "Right: %p\n", n->right);
fprintf(f, "Left: %p\n", n->left);
fprintf(f, "Down: %p\n", n->down);
fprintf(f, "Data: %p\n", n->data);
}
static void
printnodename(dns_rbtnode_t *node, bool quoted, FILE *f) {
isc_region_t r;
dns_name_t name;
char buffer[DNS_NAME_FORMATSIZE];
dns_offsets_t offsets;
r.length = NAMELEN(node);
r.base = NAME(node);
dns_name_init(&name, offsets);
dns_name_fromregion(&name, &r);
dns_name_format(&name, buffer, sizeof(buffer));
if (quoted) {
fprintf(f, "\"%s\"", buffer);
} else {
fprintf(f, "%s", buffer);
}
}
static void
print_text_helper(dns_rbtnode_t *root, dns_rbtnode_t *parent, int depth,
const char *direction, void (*data_printer)(FILE *, void *),
FILE *f) {
dns_rbt_indent(f, depth);
if (root != NULL) {
printnodename(root, true, f);
/*
* Don't use IS_RED(root) as it tests for 'root != NULL'
* and cppcheck produces false positives.
*/
fprintf(f, " (%s, %s", direction,
COLOR(root) == RED ? "RED" : "BLACK");
if ((!IS_ROOT(root) && PARENT(root) != parent) ||
(IS_ROOT(root) && depth > 0 && DOWN(PARENT(root)) != root))
{
fprintf(f, " (BAD parent pointer! -> ");
if (PARENT(root) != NULL) {
printnodename(PARENT(root), true, f);
} else {
fprintf(f, "NULL");
}
fprintf(f, ")");
}
fprintf(f, ")");
if (root->data != NULL && data_printer != NULL) {
fprintf(f, " data@%p: ", root->data);
data_printer(f, root->data);
}
fprintf(f, "\n");
depth++;
/*
* Don't use IS_RED(root) as it tests for 'root != NULL'
* and cppcheck produces false positives.
*/
if (COLOR(root) == RED && IS_RED(LEFT(root))) {
fprintf(f, "** Red/Red color violation on left\n");
}
print_text_helper(LEFT(root), root, depth, "left", data_printer,
f);
/*
* Don't use IS_RED(root) as cppcheck produces false positives.
*/
if (COLOR(root) == RED && IS_RED(RIGHT(root))) {
fprintf(f, "** Red/Red color violation on right\n");
}
print_text_helper(RIGHT(root), root, depth, "right",
data_printer, f);
print_text_helper(DOWN(root), NULL, depth, "down", data_printer,
f);
} else {
fprintf(f, "NULL (%s)\n", direction);
}
}
void
dns_rbt_printtext(dns_rbt_t *rbt, void (*data_printer)(FILE *, void *),
FILE *f) {
REQUIRE(VALID_RBT(rbt));
print_text_helper(rbt->root, NULL, 0, "root", data_printer, f);
}
static int
print_dot_helper(dns_rbtnode_t *node, unsigned int *nodecount,
bool show_pointers, FILE *f) {
unsigned int l, r, d;
if (node == NULL) {
return (0);
}
l = print_dot_helper(LEFT(node), nodecount, show_pointers, f);
r = print_dot_helper(RIGHT(node), nodecount, show_pointers, f);
d = print_dot_helper(DOWN(node), nodecount, show_pointers, f);
*nodecount += 1;
fprintf(f, "node%u[label = \"<f0> |<f1> ", *nodecount);
printnodename(node, false, f);
fprintf(f, "|<f2>");
if (show_pointers) {
fprintf(f, "|<f3> n=%p|<f4> p=%p", node, PARENT(node));
}
fprintf(f, "\"] [");
if (IS_RED(node)) {
fprintf(f, "color=red");
} else {
fprintf(f, "color=black");
}
/* XXXMUKS: verify that IS_ROOT() indicates subtree root and not
* forest root.
*/
if (IS_ROOT(node)) {
fprintf(f, ",penwidth=3");
}
if (IS_EMPTY(node)) {
fprintf(f, ",style=filled,fillcolor=lightgrey");
}
fprintf(f, "];\n");
if (LEFT(node) != NULL) {
fprintf(f, "\"node%u\":f0 -> \"node%u\":f1;\n", *nodecount, l);
}
if (DOWN(node) != NULL) {
fprintf(f, "\"node%u\":f1 -> \"node%u\":f1 [penwidth=5];\n",
*nodecount, d);
}
if (RIGHT(node) != NULL) {
fprintf(f, "\"node%u\":f2 -> \"node%u\":f1;\n", *nodecount, r);
}
return (*nodecount);
}
void
dns_rbt_printdot(dns_rbt_t *rbt, bool show_pointers, FILE *f) {
unsigned int nodecount = 0;
REQUIRE(VALID_RBT(rbt));
fprintf(f, "digraph g {\n");
fprintf(f, "node [shape = record,height=.1];\n");
print_dot_helper(rbt->root, &nodecount, show_pointers, f);
fprintf(f, "}\n");
}
/*
* Chain Functions
*/
void
dns_rbtnodechain_init(dns_rbtnodechain_t *chain) {
REQUIRE(chain != NULL);
/*
* Initialize 'chain'.
*/
chain->end = NULL;
chain->level_count = 0;
chain->level_matches = 0;
memset(chain->levels, 0, sizeof(chain->levels));
chain->magic = CHAIN_MAGIC;
}
isc_result_t
dns_rbtnodechain_current(dns_rbtnodechain_t *chain, dns_name_t *name,
dns_name_t *origin, dns_rbtnode_t **node) {
isc_result_t result = ISC_R_SUCCESS;
REQUIRE(VALID_CHAIN(chain));
if (node != NULL) {
*node = chain->end;
}
if (chain->end == NULL) {
return (ISC_R_NOTFOUND);
}
if (name != NULL) {
NODENAME(chain->end, name);
if (chain->level_count == 0) {
/*
* Names in the top level tree are all absolute.
* Always make 'name' relative.
*/
INSIST(dns_name_isabsolute(name));
/*
* This is cheaper than dns_name_getlabelsequence().
*/
name->labels--;
name->length--;
name->attributes &= ~DNS_NAMEATTR_ABSOLUTE;
}
}
if (origin != NULL) {
if (chain->level_count > 0) {
result = chain_name(chain, origin, false);
} else {
dns_name_copynf(dns_rootname, origin);
}
}
return (result);
}
isc_result_t
dns_rbtnodechain_prev(dns_rbtnodechain_t *chain, dns_name_t *name,
dns_name_t *origin) {
dns_rbtnode_t *current, *previous, *predecessor;
isc_result_t result = ISC_R_SUCCESS;
bool new_origin = false;
REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
predecessor = NULL;
current = chain->end;
if (LEFT(current) != NULL) {
/*
* Moving left one then right as far as possible is the
* previous node, at least for this level.
*/
current = LEFT(current);
while (RIGHT(current) != NULL) {
current = RIGHT(current);
}
predecessor = current;
} else {
/*
* No left links, so move toward the root. If at any point on
* the way there the link from parent to child is a right
* link, then the parent is the previous node, at least
* for this level.
*/
while (!IS_ROOT(current)) {
previous = current;
current = PARENT(current);
if (RIGHT(current) == previous) {
predecessor = current;
break;
}
}
}
if (predecessor != NULL) {
/*
* Found a predecessor node in this level. It might not
* really be the predecessor, however.
*/
if (DOWN(predecessor) != NULL) {
/*
* The predecessor is really down at least one level.
* Go down and as far right as possible, and repeat
* as long as the rightmost node has a down pointer.
*/
do {
/*
* XXX DCL Need to do something about origins
* here. See whether to go down, and if so
* whether it is truly what Bob calls a
* new origin.
*/
ADD_LEVEL(chain, predecessor);
predecessor = DOWN(predecessor);
/* XXX DCL duplicated from above; clever
* way to unduplicate? */
while (RIGHT(predecessor) != NULL) {
predecessor = RIGHT(predecessor);
}
} while (DOWN(predecessor) != NULL);
/* XXX DCL probably needs work on the concept */
if (origin != NULL) {
new_origin = true;
}
}
} else if (chain->level_count > 0) {
/*
* Dang, didn't find a predecessor in this level.
* Got to the root of this level without having traversed
* any right links. Ascend the tree one level; the
* node that points to this tree is the predecessor.
*/
INSIST(chain->level_count > 0 && IS_ROOT(current));
predecessor = chain->levels[--chain->level_count];
/* XXX DCL probably needs work on the concept */
/*
* Don't declare an origin change when the new origin is "."
* at the top level tree, because "." is declared as the origin
* for the second level tree.
*/
if (origin != NULL &&
(chain->level_count > 0 || OFFSETLEN(predecessor) > 1)) {
new_origin = true;
}
}
if (predecessor != NULL) {
chain->end = predecessor;
if (new_origin) {
result = dns_rbtnodechain_current(chain, name, origin,
NULL);
if (result == ISC_R_SUCCESS) {
result = DNS_R_NEWORIGIN;
}
} else {
result = dns_rbtnodechain_current(chain, name, NULL,
NULL);
}
} else {
result = ISC_R_NOMORE;
}
return (result);
}
isc_result_t
dns_rbtnodechain_down(dns_rbtnodechain_t *chain, dns_name_t *name,
dns_name_t *origin) {
dns_rbtnode_t *current, *successor;
isc_result_t result = ISC_R_SUCCESS;
bool new_origin = false;
REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
successor = NULL;
current = chain->end;
if (DOWN(current) != NULL) {
/*
* Don't declare an origin change when the new origin is "."
* at the second level tree, because "." is already declared
* as the origin for the top level tree.
*/
if (chain->level_count > 0 || OFFSETLEN(current) > 1) {
new_origin = true;
}
ADD_LEVEL(chain, current);
current = DOWN(current);
while (LEFT(current) != NULL) {
current = LEFT(current);
}
successor = current;
}
if (successor != NULL) {
chain->end = successor;
/*
* It is not necessary to use dns_rbtnodechain_current like
* the other functions because this function will never
* find a node in the topmost level. This is because the
* root level will never be more than one name, and everything
* in the megatree is a successor to that node, down at
* the second level or below.
*/
if (name != NULL) {
NODENAME(chain->end, name);
}
if (new_origin) {
if (origin != NULL) {
result = chain_name(chain, origin, false);
}
if (result == ISC_R_SUCCESS) {
result = DNS_R_NEWORIGIN;
}
} else {
result = ISC_R_SUCCESS;
}
} else {
result = ISC_R_NOMORE;
}
return (result);
}
isc_result_t
dns_rbtnodechain_nextflat(dns_rbtnodechain_t *chain, dns_name_t *name) {
dns_rbtnode_t *current, *previous, *successor;
isc_result_t result = ISC_R_SUCCESS;
REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
successor = NULL;
current = chain->end;
if (RIGHT(current) == NULL) {
while (!IS_ROOT(current)) {
previous = current;
current = PARENT(current);
if (LEFT(current) == previous) {
successor = current;
break;
}
}
} else {
current = RIGHT(current);
while (LEFT(current) != NULL) {
current = LEFT(current);
}
successor = current;
}
if (successor != NULL) {
chain->end = successor;
if (name != NULL) {
NODENAME(chain->end, name);
}
result = ISC_R_SUCCESS;
} else {
result = ISC_R_NOMORE;
}
return (result);
}
isc_result_t
dns_rbtnodechain_next(dns_rbtnodechain_t *chain, dns_name_t *name,
dns_name_t *origin) {
dns_rbtnode_t *current, *previous, *successor;
isc_result_t result = ISC_R_SUCCESS;
bool new_origin = false;
REQUIRE(VALID_CHAIN(chain) && chain->end != NULL);
successor = NULL;
current = chain->end;
/*
* If there is a level below this node, the next node is the leftmost
* node of the next level.
*/
if (DOWN(current) != NULL) {
/*
* Don't declare an origin change when the new origin is "."
* at the second level tree, because "." is already declared
* as the origin for the top level tree.
*/
if (chain->level_count > 0 || OFFSETLEN(current) > 1) {
new_origin = true;
}
ADD_LEVEL(chain, current);
current = DOWN(current);
while (LEFT(current) != NULL) {
current = LEFT(current);
}
successor = current;
} else if (RIGHT(current) == NULL) {
/*
* The successor is up, either in this level or a previous one.
* Head back toward the root of the tree, looking for any path
* that was via a left link; the successor is the node that has
* that left link. In the event the root of the level is
* reached without having traversed any left links, ascend one
* level and look for either a right link off the point of
* ascent, or search for a left link upward again, repeating
* ascends until either case is true.
*/
do {
while (!IS_ROOT(current)) {
previous = current;
current = PARENT(current);
if (LEFT(current) == previous) {
successor = current;
break;
}
}
if (successor == NULL) {
/*
* Reached the root without having traversed
* any left pointers, so this level is done.
*/
if (chain->level_count == 0) {
/*
* If the tree we are iterating over
* was modified since this chain was
* initialized in a way that caused
* node splits to occur, "current" may
* now be pointing to a root node which
* appears to be at level 0, but still
* has a parent. If that happens,
* abort. Otherwise, we are done
* looking for a successor as we really
* reached the root node on level 0.
*/
INSIST(PARENT(current) == NULL);
break;
}
current = chain->levels[--chain->level_count];
new_origin = true;
if (RIGHT(current) != NULL) {
break;
}
}
} while (successor == NULL);
}
if (successor == NULL && RIGHT(current) != NULL) {
current = RIGHT(current);
while (LEFT(current) != NULL) {
current = LEFT(current);
}
successor = current;
}
if (successor != NULL) {
/*
* If we determine that the current node is the successor to
* itself, we will run into an infinite loop, so abort instead.
*/
INSIST(chain->end != successor);
chain->end = successor;
/*
* It is not necessary to use dns_rbtnodechain_current like
* the other functions because this function will never
* find a node in the topmost level. This is because the
* root level will never be more than one name, and everything
* in the megatree is a successor to that node, down at
* the second level or below.
*/
if (name != NULL) {
NODENAME(chain->end, name);
}
if (new_origin) {
if (origin != NULL) {
result = chain_name(chain, origin, false);
}
if (result == ISC_R_SUCCESS) {
result = DNS_R_NEWORIGIN;
}
} else {
result = ISC_R_SUCCESS;
}
} else {
result = ISC_R_NOMORE;
}
return (result);
}
isc_result_t
dns_rbtnodechain_first(dns_rbtnodechain_t *chain, dns_rbt_t *rbt,
dns_name_t *name, dns_name_t *origin)
{
isc_result_t result;
REQUIRE(VALID_RBT(rbt));
REQUIRE(VALID_CHAIN(chain));
dns_rbtnodechain_reset(chain);
chain->end = rbt->root;
result = dns_rbtnodechain_current(chain, name, origin, NULL);
if (result == ISC_R_SUCCESS) {
result = DNS_R_NEWORIGIN;
}
return (result);
}
isc_result_t
dns_rbtnodechain_last(dns_rbtnodechain_t *chain, dns_rbt_t *rbt,
dns_name_t *name, dns_name_t *origin)
{
isc_result_t result;
REQUIRE(VALID_RBT(rbt));
REQUIRE(VALID_CHAIN(chain));
dns_rbtnodechain_reset(chain);
result = move_chain_to_last(chain, rbt->root);
if (result != ISC_R_SUCCESS) {
return (result);
}
result = dns_rbtnodechain_current(chain, name, origin, NULL);
if (result == ISC_R_SUCCESS) {
result = DNS_R_NEWORIGIN;
}
return (result);
}
void
dns_rbtnodechain_reset(dns_rbtnodechain_t *chain) {
REQUIRE(VALID_CHAIN(chain));
/*
* Free any dynamic storage associated with 'chain', and then
* reinitialize 'chain'.
*/
chain->end = NULL;
chain->level_count = 0;
chain->level_matches = 0;
}
void
dns_rbtnodechain_invalidate(dns_rbtnodechain_t *chain) {
/*
* Free any dynamic storage associated with 'chain', and then
* invalidate 'chain'.
*/
dns_rbtnodechain_reset(chain);
chain->magic = 0;
}
/* XXXMUKS:
*
* - worth removing inline as static functions are inlined automatically
* where suitable by modern compilers.
* - bump the size of dns_rbt.nodecount to size_t.
* - the dumpfile header also contains a nodecount that is unsigned
* int. If large files (> 2^32 nodes) are to be supported, the
* allocation for this field should be increased.
*/
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