The Tor Browser: security/nss/lib/dbm/src/hash.c@6474c204b198 (annotated)

security/nss/lib/dbm/src/hash.c@6474c204b198 (annotated)

security/nss/lib/dbm/src/hash.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*-
  * Copyright (c) 1990, 1993, 1994
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Margo Seltzer.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. ***REMOVED*** - see
  *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
  * 4. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 #if defined(LIBC_SCCS) && !defined(lint)
 static char sccsid[] = "@(#)hash.c	8.9 (Berkeley) 6/16/94";
 #endif /* LIBC_SCCS and not lint */
 #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
 #include <sys/param.h>
 #endif
 #if !defined(macintosh)
 #ifdef XP_OS2
 #include <sys/types.h>
 #endif
 #include <sys/stat.h>
 #endif
 #if defined(macintosh)
 #include <unix.h>
 #include <unistd.h>
 #endif
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
 #include <unistd.h>
 #endif
 #if defined(_WIN32) || defined(_WINDOWS)
 #include <windows.h>
 #endif
 #include <assert.h>
 #include "mcom_db.h"
 #include "hash.h"
 #include "page.h"
 /*
 #include "extern.h"
 */
 static int   alloc_segs __P((HTAB *, int));
 static int   flush_meta __P((HTAB *));
 static int   hash_access __P((HTAB *, ACTION, DBT *, DBT *));
 static int   hash_close __P((DB *));
 static int   hash_delete __P((const DB *, const DBT *, uint));
 static int   hash_fd __P((const DB *));
 static int   hash_get __P((const DB *, const DBT *, DBT *, uint));
 static int   hash_put __P((const DB *, DBT *, const DBT *, uint));
 static void *hash_realloc __P((SEGMENT **, size_t, size_t));
 static int   hash_seq __P((const DB *, DBT *, DBT *, uint));
 static int   hash_sync __P((const DB *, uint));
 static int   hdestroy __P((HTAB *));
 static HTAB *init_hash __P((HTAB *, const char *, HASHINFO *));
 static int   init_htab __P((HTAB *, int));
 #if BYTE_ORDER == LITTLE_ENDIAN
 static void  swap_header __P((HTAB *));
 static void  swap_header_copy __P((HASHHDR *, HASHHDR *));
 #endif
 /* Fast arithmetic, relying on powers of 2, */
 #define MOD(x, y)		((x) & ((y) - 1))
 #define RETURN_ERROR(ERR, LOC)	{ save_errno = ERR; goto LOC; }
 /* Return values */
 #define	SUCCESS	 (0)
 #define	DBM_ERROR	(-1)
 #define	ABNORMAL (1)
 #ifdef HASH_STATISTICS
 int hash_accesses, hash_collisions, hash_expansions, hash_overflows;
 #endif
 /* A new Lou (montulli@mozilla.com) routine.
  *
  * The database is screwed.
  *
  * This closes the file, flushing buffers as appropriate.
  */
 static void
 __remove_database(DB *dbp)
 {
 	HTAB *hashp = (HTAB *)dbp->internal;
 	assert(0);
 	if (!hashp)
 		return;
 	hdestroy(hashp);
 	dbp->internal = NULL;
 }
 /************************** INTERFACE ROUTINES ***************************/
 /* OPEN/CLOSE */
 extern DB *
 __hash_open(const char *file, int flags, int mode, const HASHINFO *info, int dflags)
 {
 	HTAB *hashp=NULL;
 	struct stat statbuf;
 	DB *dbp;
 	int bpages, hdrsize, new_table, nsegs, save_errno;
 	if ((flags & O_ACCMODE) == O_WRONLY) {
 		errno = EINVAL;
 		return NULL;
 	}
 	/* zero the statbuffer so that
 	 * we can check it for a non-zero
 	 * date to see if stat succeeded
 	 */
 	memset(&statbuf, 0, sizeof(struct stat));
 	if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB)))) {
 		errno = ENOMEM;
 		return NULL;
 	}
 	hashp->fp = NO_FILE;
 	if(file)
 		hashp->filename = strdup(file);
 	/*
 	 * Even if user wants write only, we need to be able to read
 	 * the actual file, so we need to open it read/write. But, the
 	 * field in the hashp structure needs to be accurate so that
 	 * we can check accesses.
 	 */
 	hashp->flags = flags;
 	new_table = 0;
 	if (!file || (flags & O_TRUNC) 	|| (stat(file, &statbuf)  && (errno == ENOENT)))
 	{
 		if (errno == ENOENT)
 			errno = 0; /* Just in case someone looks at errno */
 		new_table = 1;
 	}
 	else if(statbuf.st_mtime && statbuf.st_size == 0)
 	{
 		/* check for a zero length file and delete it
 	 	 * if it exists
 	 	 */
 		new_table = 1;
 	}
 	hashp->file_size = statbuf.st_size;
 	if (file) {
 #if defined(_WIN32) || defined(_WINDOWS) || defined (macintosh)  || defined(XP_OS2)
 		if ((hashp->fp = DBFILE_OPEN(file, flags | O_BINARY, mode)) == -1)
 			RETURN_ERROR(errno, error1);
 #else
 		if ((hashp->fp = open(file, flags, mode)) == -1)
 			RETURN_ERROR(errno, error1);
 		(void)fcntl(hashp->fp, F_SETFD, 1);
 #endif
 	}
 	if (new_table) {
 		if (!init_hash(hashp, file, (HASHINFO *)info))
 			RETURN_ERROR(errno, error1);
 	} else {
 		/* Table already exists */
 		if (info && info->hash)
 			hashp->hash = info->hash;
 		else
 			hashp->hash = __default_hash;
 		hdrsize = read(hashp->fp, (char *)&hashp->hdr, sizeof(HASHHDR));
 		if (hdrsize == -1)
 			RETURN_ERROR(errno, error1);
 		if (hdrsize != sizeof(HASHHDR))
 			RETURN_ERROR(EFTYPE, error1);
 #if BYTE_ORDER == LITTLE_ENDIAN
 		swap_header(hashp);
 #endif
 		/* Verify file type, versions and hash function */
 		if (hashp->MAGIC != HASHMAGIC)
 			RETURN_ERROR(EFTYPE, error1);
 #define	OLDHASHVERSION	1
 		if (hashp->VERSION != HASHVERSION &&
 		    hashp->VERSION != OLDHASHVERSION)
 			RETURN_ERROR(EFTYPE, error1);
 		if (hashp->hash(CHARKEY, sizeof(CHARKEY)) != hashp->H_CHARKEY)
 			RETURN_ERROR(EFTYPE, error1);
 		if (hashp->NKEYS < 0) /* Old bad database. */
 			RETURN_ERROR(EFTYPE, error1);
 		/*
 		 * Figure out how many segments we need.  Max_Bucket is the
 		 * maximum bucket number, so the number of buckets is
 		 * max_bucket + 1.
 		 */
 		nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) /
 			 hashp->SGSIZE;
 		hashp->nsegs = 0;
 		if (alloc_segs(hashp, nsegs))
 			/* If alloc_segs fails, errno will have been set.  */
 			RETURN_ERROR(errno, error1);
 		/* Read in bitmaps */
 		bpages = (hashp->SPARES[hashp->OVFL_POINT] +
 		    (hashp->BSIZE << BYTE_SHIFT) - 1) >>
 		    (hashp->BSHIFT + BYTE_SHIFT);
 		hashp->nmaps = bpages;
 		(void)memset(&hashp->mapp[0], 0, bpages * sizeof(uint32 *));
 	}
 	/* Initialize Buffer Manager */
 	if (info && info->cachesize)
 		__buf_init(hashp, (int32) info->cachesize);
 	else
 		__buf_init(hashp, DEF_BUFSIZE);
 	hashp->new_file = new_table;
 #ifdef macintosh
 	hashp->save_file = file && !(hashp->flags & O_RDONLY);
 #else
 	hashp->save_file = file && (hashp->flags & O_RDWR);
 #endif
 	hashp->cbucket = -1;
 	if (!(dbp = (DB *)malloc(sizeof(DB)))) {
 		RETURN_ERROR(ENOMEM, error1);
 	}
 	dbp->internal = hashp;
 	dbp->close = hash_close;
 	dbp->del = hash_delete;
 	dbp->fd = hash_fd;
 	dbp->get = hash_get;
 	dbp->put = hash_put;
 	dbp->seq = hash_seq;
 	dbp->sync = hash_sync;
 	dbp->type = DB_HASH;
 #ifdef HASH_STATISTICS
 	hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
 #endif
 	return (dbp);
 error1:
 	hdestroy(hashp);
 	errno = save_errno;
 	return (NULL);
 }
 static int
 hash_close(DB *dbp)
 {
 	HTAB *hashp;
 	int retval;
 	if (!dbp)
 		return (DBM_ERROR);
 	hashp = (HTAB *)dbp->internal;
 	if(!hashp)
 		return (DBM_ERROR);
 	retval = hdestroy(hashp);
 	free(dbp);
 	return (retval);
 }
 static int hash_fd(const DB *dbp)
 {
 	HTAB *hashp;
 	if (!dbp)
 		return (DBM_ERROR);
 	hashp = (HTAB *)dbp->internal;
 	if(!hashp)
 		return (DBM_ERROR);
 	if (hashp->fp == -1) {
 		errno = ENOENT;
 		return (-1);
 	}
 	return (hashp->fp);
 }
 /************************** LOCAL CREATION ROUTINES **********************/
 static HTAB *
 init_hash(HTAB *hashp, const char *file, HASHINFO *info)
 {
 	struct stat statbuf;
 	int nelem;
 	nelem = 1;
 	hashp->NKEYS = 0;
 	hashp->LORDER = BYTE_ORDER;
 	hashp->BSIZE = DEF_BUCKET_SIZE;
 	hashp->BSHIFT = DEF_BUCKET_SHIFT;
 	hashp->SGSIZE = DEF_SEGSIZE;
 	hashp->SSHIFT = DEF_SEGSIZE_SHIFT;
 	hashp->DSIZE = DEF_DIRSIZE;
 	hashp->FFACTOR = DEF_FFACTOR;
 	hashp->hash = __default_hash;
 	memset(hashp->SPARES, 0, sizeof(hashp->SPARES));
 	memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS));
 	/* Fix bucket size to be optimal for file system */
 	if (file != NULL) {
 		if (stat(file, &statbuf))
 			return (NULL);
 #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh) && !defined(XP_OS2)
 #if defined(__QNX__) && !defined(__QNXNTO__)
 		hashp->BSIZE = 512; /* preferred blk size on qnx4 */
 #else
 		hashp->BSIZE = statbuf.st_blksize;
 #endif
 		/* new code added by Lou to reduce block
 		 * size down below MAX_BSIZE
 		 */
 		if (hashp->BSIZE > MAX_BSIZE)
 			hashp->BSIZE = MAX_BSIZE;
 #endif
 		hashp->BSHIFT = __log2((uint32)hashp->BSIZE);
 	}
 	if (info) {
 		if (info->bsize) {
 			/* Round pagesize up to power of 2 */
 			hashp->BSHIFT = __log2(info->bsize);
 			hashp->BSIZE = 1 << hashp->BSHIFT;
 			if (hashp->BSIZE > MAX_BSIZE) {
 				errno = EINVAL;
 				return (NULL);
 			}
 		}
 		if (info->ffactor)
 			hashp->FFACTOR = info->ffactor;
 		if (info->hash)
 			hashp->hash = info->hash;
 		if (info->nelem)
 			nelem = info->nelem;
 		if (info->lorder) {
 			if (info->lorder != BIG_ENDIAN &&
 			    info->lorder != LITTLE_ENDIAN) {
 				errno = EINVAL;
 				return (NULL);
 			}
 			hashp->LORDER = info->lorder;
 		}
 	}
 	/* init_htab sets errno if it fails */
 	if (init_htab(hashp, nelem))
 		return (NULL);
 	else
 		return (hashp);
 }
 /*
  * This calls alloc_segs which may run out of memory.  Alloc_segs will
  * set errno, so we just pass the error information along.
  *
  * Returns 0 on No Error
  */
 static int
 init_htab(HTAB *hashp, int nelem)
 {
 	register int nbuckets, nsegs;
 	int l2;
 	/*
 	 * Divide number of elements by the fill factor and determine a
 	 * desired number of buckets.  Allocate space for the next greater
 	 * power of two number of buckets.
 	 */
 	nelem = (nelem - 1) / hashp->FFACTOR + 1;
 	l2 = __log2((uint32)PR_MAX(nelem, 2));
 	nbuckets = 1 << l2;
 	hashp->SPARES[l2] = l2 + 1;
 	hashp->SPARES[l2 + 1] = l2 + 1;
 	hashp->OVFL_POINT = l2;
 	hashp->LAST_FREED = 2;
 	/* First bitmap page is at: splitpoint l2 page offset 1 */
 	if (__ibitmap(hashp, (int)OADDR_OF(l2, 1), l2 + 1, 0))
 		return (-1);
 	hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1;
 	hashp->HIGH_MASK = (nbuckets << 1) - 1;
 	hashp->HDRPAGES = ((PR_MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >>
 	    hashp->BSHIFT) + 1;
 	nsegs = (nbuckets - 1) / hashp->SGSIZE + 1;
 	nsegs = 1 << __log2((uint32)nsegs);
 	if (nsegs > hashp->DSIZE)
 		hashp->DSIZE = nsegs;
 	return (alloc_segs(hashp, nsegs));
 }
 /********************** DESTROY/CLOSE ROUTINES ************************/
 /*
  * Flushes any changes to the file if necessary and destroys the hashp
  * structure, freeing all allocated space.
  */
 static int
 hdestroy(HTAB *hashp)
 {
 	int i, save_errno;
 	save_errno = 0;
 #ifdef HASH_STATISTICS
 	(void)fprintf(stderr, "hdestroy: accesses %ld collisions %ld\n",
 	    hash_accesses, hash_collisions);
 	(void)fprintf(stderr, "hdestroy: expansions %ld\n",
 	    hash_expansions);
 	(void)fprintf(stderr, "hdestroy: overflows %ld\n",
 	    hash_overflows);
 	(void)fprintf(stderr, "keys %ld maxp %d segmentcount %d\n",
 	    hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs);
 	for (i = 0; i < NCACHED; i++)
 		(void)fprintf(stderr,
 		    "spares[%d] = %d\n", i, hashp->SPARES[i]);
 #endif
 	/*
 	 * Call on buffer manager to free buffers, and if required,
 	 * write them to disk.
 	 */
 	if (__buf_free(hashp, 1, hashp->save_file))
 		save_errno = errno;
 	if (hashp->dir) {
 		free(*hashp->dir);	/* Free initial segments */
 		/* Free extra segments */
 		while (hashp->exsegs--)
 			free(hashp->dir[--hashp->nsegs]);
 		free(hashp->dir);
 	}
 	if (flush_meta(hashp) && !save_errno)
 		save_errno = errno;
 	/* Free Bigmaps */
 	for (i = 0; i < hashp->nmaps; i++)
 		if (hashp->mapp[i])
 			free(hashp->mapp[i]);
 	if (hashp->fp != -1)
 		(void)close(hashp->fp);
 	if(hashp->filename) {
 #if defined(_WIN32) || defined(_WINDOWS) || defined(XP_OS2)
 		if (hashp->is_temp)
 			(void)unlink(hashp->filename);
 #endif
 		free(hashp->filename);
 	}
 	if (hashp->tmp_buf)
 	    free(hashp->tmp_buf);
 	if (hashp->tmp_key)
 	    free(hashp->tmp_key);
 	free(hashp);
 	if (save_errno) {
 		errno = save_errno;
 		return (DBM_ERROR);
 	}
 	return (SUCCESS);
 }
 #if defined(_WIN32) || defined(_WINDOWS)
 /*
  * Close and reopen file to force file length update on windows.
  *
  * Returns:
  *	 0 == OK
  *	-1 DBM_ERROR
  */
 static int
 update_EOF(HTAB *hashp)
 {
 #if defined(DBM_REOPEN_ON_FLUSH)
 	char *      file       = hashp->filename;
 	off_t       file_size;
 	int         flags;
 	int         mode       = -1;
 	struct stat statbuf;
 	memset(&statbuf, 0, sizeof statbuf);
 	/* make sure we won't lose the file by closing it. */
 	if (!file || (stat(file, &statbuf)  && (errno == ENOENT)))  {
 		/* pretend we did it. */
 		return 0;
 	}
 	(void)close(hashp->fp);
 	flags = hashp->flags & ~(O_TRUNC | O_CREAT | O_EXCL);
 	if ((hashp->fp = DBFILE_OPEN(file, flags | O_BINARY, mode)) == -1)
 		return -1;
 	file_size = lseek(hashp->fp, (off_t)0, SEEK_END);
 	if (file_size == -1)
 		return -1;
 	hashp->file_size = file_size;
 	return 0;
 #else
 	int    fd        = hashp->fp;
 	off_t  file_size = lseek(fd, (off_t)0, SEEK_END);
 	HANDLE handle    = (HANDLE)_get_osfhandle(fd);
 	BOOL   cool      = FlushFileBuffers(handle);
 #ifdef DEBUG3
 	if (!cool) {
 		DWORD err = GetLastError();
 		(void)fprintf(stderr,
 			"FlushFileBuffers failed, last error = %d, 0x%08x\n",
 			err, err);
 	}
 #endif
 	if (file_size == -1)
 		return -1;
 	hashp->file_size = file_size;
 	return cool ? 0 : -1;
 #endif
 }
 #endif
 /*
  * Write modified pages to disk
  *
  * Returns:
  *	 0 == OK
  *	-1 DBM_ERROR
  */
 static int
 hash_sync(const DB *dbp, uint flags)
 {
 	HTAB *hashp;
 	if (flags != 0) {
 		errno = EINVAL;
 		return (DBM_ERROR);
 	}
 	if (!dbp)
 		return (DBM_ERROR);
 	hashp = (HTAB *)dbp->internal;
 	if(!hashp)
 		return (DBM_ERROR);
 	if (!hashp->save_file)
 		return (0);
 	if (__buf_free(hashp, 0, 1) || flush_meta(hashp))
 		return (DBM_ERROR);
 #if defined(_WIN32) || defined(_WINDOWS)
 	if (hashp->updateEOF && hashp->filename && !hashp->is_temp) {
 		int status = update_EOF(hashp);
 		hashp->updateEOF = 0;
 		if (status)
 			return status;
 	}
 #endif
 	hashp->new_file = 0;
 	return (0);
 }
 /*
  * Returns:
  *	 0 == OK
  *	-1 indicates that errno should be set
  */
 static int
 flush_meta(HTAB *hashp)
 {
 	HASHHDR *whdrp;
 #if BYTE_ORDER == LITTLE_ENDIAN
 	HASHHDR whdr;
 #endif
 	int fp, i, wsize;
 	if (!hashp->save_file)
 		return (0);
 	hashp->MAGIC = HASHMAGIC;
 	hashp->VERSION = HASHVERSION;
 	hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY));
 	fp = hashp->fp;
 	whdrp = &hashp->hdr;
 #if BYTE_ORDER == LITTLE_ENDIAN
 	whdrp = &whdr;
 	swap_header_copy(&hashp->hdr, whdrp);
 #endif
 	if ((lseek(fp, (off_t)0, SEEK_SET) == -1) ||
 	    ((wsize = write(fp, (char*)whdrp, sizeof(HASHHDR))) == -1))
 		return (-1);
 	else
 		if (wsize != sizeof(HASHHDR)) {
 			errno = EFTYPE;
 			hashp->dbmerrno = errno;
 			return (-1);
 		}
 	for (i = 0; i < NCACHED; i++)
 		if (hashp->mapp[i])
 			if (__put_page(hashp, (char *)hashp->mapp[i],
 				hashp->BITMAPS[i], 0, 1))
 				return (-1);
 	return (0);
 }
 /*******************************SEARCH ROUTINES *****************************/
 /*
  * All the access routines return
  *
  * Returns:
  *	 0 on SUCCESS
  *	 1 to indicate an external DBM_ERROR (i.e. key not found, etc)
  *	-1 to indicate an internal DBM_ERROR (i.e. out of memory, etc)
  */
 static int
 hash_get(
 	const DB *dbp,
 	const DBT *key,
 	DBT *data,
 	uint flag)
 {
 	HTAB *hashp;
 	int rv;
 	hashp = (HTAB *)dbp->internal;
 	if (!hashp)
 		return (DBM_ERROR);
 	if (flag) {
 		hashp->dbmerrno = errno = EINVAL;
 		return (DBM_ERROR);
 	}
 	rv = hash_access(hashp, HASH_GET, (DBT *)key, data);
 	if(rv == DATABASE_CORRUPTED_ERROR)
 	  {
 #if defined(unix) && defined(DEBUG)
 		printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
 #endif
 	  	__remove_database((DB *)dbp);
 	  }
 	return(rv);
 }
 static int
 hash_put(
 	const DB *dbp,
 	DBT *key,
 	const DBT *data,
 	uint flag)
 {
 	HTAB *hashp;
 	int rv;
 	hashp = (HTAB *)dbp->internal;
 	if (!hashp)
 		return (DBM_ERROR);
 	if (flag && flag != R_NOOVERWRITE) {
 		hashp->dbmerrno = errno = EINVAL;
 		return (DBM_ERROR);
 	}
 	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
 		hashp->dbmerrno = errno = EPERM;
 		return (DBM_ERROR);
 	}
 	rv =  hash_access(hashp, flag == R_NOOVERWRITE ?
 	    HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data);
 	if(rv == DATABASE_CORRUPTED_ERROR)
 	  {
 #if defined(unix) && defined(DEBUG)
 		printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
 #endif
 	  	__remove_database((DB *)dbp);
 	  }
 	return(rv);
 }
 static int
 hash_delete(
 	const DB *dbp,
 	const DBT *key,
 	uint flag)		/* Ignored */
 {
 	HTAB *hashp;
 	int rv;
 	hashp = (HTAB *)dbp->internal;
 	if (!hashp)
 		return (DBM_ERROR);
 	if (flag && flag != R_CURSOR) {
 		hashp->dbmerrno = errno = EINVAL;
 		return (DBM_ERROR);
 	}
 	if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
 		hashp->dbmerrno = errno = EPERM;
 		return (DBM_ERROR);
 	}
 	rv = hash_access(hashp, HASH_DELETE, (DBT *)key, NULL);
 	if(rv == DATABASE_CORRUPTED_ERROR)
 	  {
 #if defined(unix) && defined(DEBUG)
 		printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
 #endif
 	  	__remove_database((DB *)dbp);
 	  }
 	return(rv);
 }
 #define MAX_OVERFLOW_HASH_ACCESS_LOOPS 2000
 /*
  * Assume that hashp has been set in wrapper routine.
  */
 static int
 hash_access(
 	HTAB *hashp,
 	ACTION action,
 	DBT *key, DBT *val)
 {
 	register BUFHEAD *rbufp;
 	BUFHEAD *bufp, *save_bufp;
 	register uint16 *bp;
 	register long n, ndx, off;
 	register size_t size;
 	register char *kp;
 	uint16 pageno;
 	uint32 ovfl_loop_count=0;
     int32 last_overflow_page_no = -1;
 #ifdef HASH_STATISTICS
 	hash_accesses++;
 #endif
 	off = hashp->BSIZE;
 	size = key->size;
 	kp = (char *)key->data;
 	rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
 	if (!rbufp)
 		return (DATABASE_CORRUPTED_ERROR);
 	save_bufp = rbufp;
 	/* Pin the bucket chain */
 	rbufp->flags |= BUF_PIN;
 	for (bp = (uint16 *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
 	{
 		if (bp[1] >= REAL_KEY) {
 			/* Real key/data pair */
 			if (size == (unsigned long)(off - *bp) &&
 			    memcmp(kp, rbufp->page + *bp, size) == 0)
 				goto found;
 			off = bp[1];
 #ifdef HASH_STATISTICS
 			hash_collisions++;
 #endif
 			bp += 2;
 			ndx += 2;
 		} else if (bp[1] == OVFLPAGE) {
             /* database corruption: overflow loop detection */
             if(last_overflow_page_no == (int32)*bp)
     			return (DATABASE_CORRUPTED_ERROR);
             last_overflow_page_no = *bp;
 			rbufp = __get_buf(hashp, *bp, rbufp, 0);
 			if (!rbufp) {
 				save_bufp->flags &= ~BUF_PIN;
 				return (DBM_ERROR);
 			}
             ovfl_loop_count++;
             if(ovfl_loop_count > MAX_OVERFLOW_HASH_ACCESS_LOOPS)
     			return (DATABASE_CORRUPTED_ERROR);
 			/* FOR LOOP INIT */
 			bp = (uint16 *)rbufp->page;
 			n = *bp++;
 			ndx = 1;
 			off = hashp->BSIZE;
 		} else if (bp[1] < REAL_KEY) {
 			if ((ndx =
 			    __find_bigpair(hashp, rbufp, ndx, kp, (int)size)) > 0)
 				goto found;
 			if (ndx == -2) {
 				bufp = rbufp;
 				if (!(pageno =
 				    __find_last_page(hashp, &bufp))) {
 					ndx = 0;
 					rbufp = bufp;
 					break;	/* FOR */
 				}
 				rbufp = __get_buf(hashp, pageno, bufp, 0);
 				if (!rbufp) {
 					save_bufp->flags &= ~BUF_PIN;
 					return (DBM_ERROR);
 				}
 				/* FOR LOOP INIT */
 				bp = (uint16 *)rbufp->page;
 				n = *bp++;
 				ndx = 1;
 				off = hashp->BSIZE;
 			} else {
 				save_bufp->flags &= ~BUF_PIN;
 				return (DBM_ERROR);
 			}
 		}
 	}
 	/* Not found */
 	switch (action) {
 	case HASH_PUT:
 	case HASH_PUTNEW:
 		if (__addel(hashp, rbufp, key, val)) {
 			save_bufp->flags &= ~BUF_PIN;
 			return (DBM_ERROR);
 		} else {
 			save_bufp->flags &= ~BUF_PIN;
 			return (SUCCESS);
 		}
 	case HASH_GET:
 	case HASH_DELETE:
 	default:
 		save_bufp->flags &= ~BUF_PIN;
 		return (ABNORMAL);
 	}
 found:
 	switch (action) {
 	case HASH_PUTNEW:
 		save_bufp->flags &= ~BUF_PIN;
 		return (ABNORMAL);
 	case HASH_GET:
 		bp = (uint16 *)rbufp->page;
 		if (bp[ndx + 1] < REAL_KEY) {
 			if (__big_return(hashp, rbufp, ndx, val, 0))
 				return (DBM_ERROR);
 		} else {
 			val->data = (uint8 *)rbufp->page + (int)bp[ndx + 1];
 			val->size = bp[ndx] - bp[ndx + 1];
 		}
 		break;
 	case HASH_PUT:
 		if ((__delpair(hashp, rbufp, ndx)) ||
 		    (__addel(hashp, rbufp, key, val))) {
 			save_bufp->flags &= ~BUF_PIN;
 			return (DBM_ERROR);
 		}
 		break;
 	case HASH_DELETE:
 		if (__delpair(hashp, rbufp, ndx))
 			return (DBM_ERROR);
 		break;
 	default:
 		abort();
 	}
 	save_bufp->flags &= ~BUF_PIN;
 	return (SUCCESS);
 }
 static int
 hash_seq(
 	const DB *dbp,
 	DBT *key, DBT *data,
 	uint flag)
 {
 	register uint32 bucket;
 	register BUFHEAD *bufp;
 	HTAB *hashp;
 	uint16 *bp, ndx;
 	hashp = (HTAB *)dbp->internal;
 	if (!hashp)
 		return (DBM_ERROR);
 	if (flag && flag != R_FIRST && flag != R_NEXT) {
 		hashp->dbmerrno = errno = EINVAL;
 		return (DBM_ERROR);
 	}
 #ifdef HASH_STATISTICS
 	hash_accesses++;
 #endif
 	if ((hashp->cbucket < 0) || (flag == R_FIRST)) {
 		hashp->cbucket = 0;
 		hashp->cndx = 1;
 		hashp->cpage = NULL;
 	}
 	for (bp = NULL; !bp || !bp[0]; ) {
 		if (!(bufp = hashp->cpage)) {
 			for (bucket = hashp->cbucket;
 			    bucket <= (uint32)hashp->MAX_BUCKET;
 			    bucket++, hashp->cndx = 1) {
 				bufp = __get_buf(hashp, bucket, NULL, 0);
 				if (!bufp)
 					return (DBM_ERROR);
 				hashp->cpage = bufp;
 				bp = (uint16 *)bufp->page;
 				if (bp[0])
 					break;
 			}
 			hashp->cbucket = bucket;
 			if (hashp->cbucket > hashp->MAX_BUCKET) {
 				hashp->cbucket = -1;
 				return (ABNORMAL);
 			}
 		} else
 			bp = (uint16 *)hashp->cpage->page;
 #ifdef DEBUG
 		assert(bp);
 		assert(bufp);
 #endif
 		while (bp[hashp->cndx + 1] == OVFLPAGE) {
 			bufp = hashp->cpage =
 			    __get_buf(hashp, bp[hashp->cndx], bufp, 0);
 			if (!bufp)
 				return (DBM_ERROR);
 			bp = (uint16 *)(bufp->page);
 			hashp->cndx = 1;
 		}
 		if (!bp[0]) {
 			hashp->cpage = NULL;
 			++hashp->cbucket;
 		}
 	}
 	ndx = hashp->cndx;
 	if (bp[ndx + 1] < REAL_KEY) {
 		if (__big_keydata(hashp, bufp, key, data, 1))
 			return (DBM_ERROR);
 	} else {
 		key->data = (uint8 *)hashp->cpage->page + bp[ndx];
 		key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
 		data->data = (uint8 *)hashp->cpage->page + bp[ndx + 1];
 		data->size = bp[ndx] - bp[ndx + 1];
 		ndx += 2;
 		if (ndx > bp[0]) {
 			hashp->cpage = NULL;
 			hashp->cbucket++;
 			hashp->cndx = 1;
 		} else
 			hashp->cndx = ndx;
 	}
 	return (SUCCESS);
 }
 /********************************* UTILITIES ************************/
 /*
  * Returns:
  *	 0 ==> OK
  *	-1 ==> Error
  */
 extern int
 __expand_table(HTAB *hashp)
 {
 	uint32 old_bucket, new_bucket;
 	int new_segnum, spare_ndx;
 	size_t dirsize;
 #ifdef HASH_STATISTICS
 	hash_expansions++;
 #endif
 	new_bucket = ++hashp->MAX_BUCKET;
 	old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK);
 	new_segnum = new_bucket >> hashp->SSHIFT;
 	/* Check if we need a new segment */
 	if (new_segnum >= hashp->nsegs) {
 		/* Check if we need to expand directory */
 		if (new_segnum >= hashp->DSIZE) {
 			/* Reallocate directory */
 			dirsize = hashp->DSIZE * sizeof(SEGMENT *);
 			if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1))
 				return (-1);
 			hashp->DSIZE = dirsize << 1;
 		}
 		if ((hashp->dir[new_segnum] =
 		    (SEGMENT)calloc((size_t)hashp->SGSIZE, sizeof(SEGMENT))) == NULL)
 			return (-1);
 		hashp->exsegs++;
 		hashp->nsegs++;
 	}
 	/*
 	 * If the split point is increasing (MAX_BUCKET's log base 2
 	 * * increases), we need to copy the current contents of the spare
 	 * split bucket to the next bucket.
 	 */
 	spare_ndx = __log2((uint32)(hashp->MAX_BUCKET + 1));
 	if (spare_ndx > hashp->OVFL_POINT) {
 		hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT];
 		hashp->OVFL_POINT = spare_ndx;
 	}
 	if (new_bucket > (uint32)hashp->HIGH_MASK) {
 		/* Starting a new doubling */
 		hashp->LOW_MASK = hashp->HIGH_MASK;
 		hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK;
 	}
 	/* Relocate records to the new bucket */
 	return (__split_page(hashp, old_bucket, new_bucket));
 }
 /*
  * If realloc guarantees that the pointer is not destroyed if the realloc
  * fails, then this routine can go away.
  */
 static void *
 hash_realloc(
 	SEGMENT **p_ptr,
 	size_t oldsize, size_t newsize)
 {
 	register void *p;
 	if ((p = malloc(newsize))) {
 		memmove(p, *p_ptr, oldsize);
 		memset((char *)p + oldsize, 0, newsize - oldsize);
 		free(*p_ptr);
 		*p_ptr = (SEGMENT *)p;
 	}
 	return (p);
 }
 extern uint32
 __call_hash(HTAB *hashp, char *k, size_t len)
 {
 	uint32 n, bucket;
 	n = hashp->hash(k, len);
 	bucket = n & hashp->HIGH_MASK;
 	if (bucket > (uint32)hashp->MAX_BUCKET)
 		bucket = bucket & hashp->LOW_MASK;
 	return (bucket);
 }
 /*
  * Allocate segment table.  On error, set errno.
  *
  * Returns 0 on success
  */
 static int
 alloc_segs(
 	HTAB *hashp,
 	int nsegs)
 {
 	register int i;
 	register SEGMENT store;
 	if ((hashp->dir =
 	    (SEGMENT *)calloc((size_t)hashp->DSIZE, sizeof(SEGMENT *))) == NULL) {
 		errno = ENOMEM;
 		return (-1);
 	}
 	/* Allocate segments */
 	if ((store =
 	    (SEGMENT)calloc((size_t)nsegs << hashp->SSHIFT, sizeof(SEGMENT))) == NULL) {
 		errno = ENOMEM;
 		return (-1);
 	}
 	for (i = 0; i < nsegs; i++, hashp->nsegs++)
 		hashp->dir[i] = &store[i << hashp->SSHIFT];
 	return (0);
 }
 #if BYTE_ORDER == LITTLE_ENDIAN
 /*
  * Hashp->hdr needs to be byteswapped.
  */
 static void
 swap_header_copy(
 	HASHHDR *srcp, HASHHDR *destp)
 {
 	int i;
 	P_32_COPY(srcp->magic, destp->magic);
 	P_32_COPY(srcp->version, destp->version);
 	P_32_COPY(srcp->lorder, destp->lorder);
 	P_32_COPY(srcp->bsize, destp->bsize);
 	P_32_COPY(srcp->bshift, destp->bshift);
 	P_32_COPY(srcp->dsize, destp->dsize);
 	P_32_COPY(srcp->ssize, destp->ssize);
 	P_32_COPY(srcp->sshift, destp->sshift);
 	P_32_COPY(srcp->ovfl_point, destp->ovfl_point);
 	P_32_COPY(srcp->last_freed, destp->last_freed);
 	P_32_COPY(srcp->max_bucket, destp->max_bucket);
 	P_32_COPY(srcp->high_mask, destp->high_mask);
 	P_32_COPY(srcp->low_mask, destp->low_mask);
 	P_32_COPY(srcp->ffactor, destp->ffactor);
 	P_32_COPY(srcp->nkeys, destp->nkeys);
 	P_32_COPY(srcp->hdrpages, destp->hdrpages);
 	P_32_COPY(srcp->h_charkey, destp->h_charkey);
 	for (i = 0; i < NCACHED; i++) {
 		P_32_COPY(srcp->spares[i], destp->spares[i]);
 		P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]);
 	}
 }
 static void
 swap_header(HTAB *hashp)
 {
 	HASHHDR *hdrp;
 	int i;
 	hdrp = &hashp->hdr;
 	M_32_SWAP(hdrp->magic);
 	M_32_SWAP(hdrp->version);
 	M_32_SWAP(hdrp->lorder);
 	M_32_SWAP(hdrp->bsize);
 	M_32_SWAP(hdrp->bshift);
 	M_32_SWAP(hdrp->dsize);
 	M_32_SWAP(hdrp->ssize);
 	M_32_SWAP(hdrp->sshift);
 	M_32_SWAP(hdrp->ovfl_point);
 	M_32_SWAP(hdrp->last_freed);
 	M_32_SWAP(hdrp->max_bucket);
 	M_32_SWAP(hdrp->high_mask);
 	M_32_SWAP(hdrp->low_mask);
 	M_32_SWAP(hdrp->ffactor);
 	M_32_SWAP(hdrp->nkeys);
 	M_32_SWAP(hdrp->hdrpages);
 	M_32_SWAP(hdrp->h_charkey);
 	for (i = 0; i < NCACHED; i++) {
 		M_32_SWAP(hdrp->spares[i]);
 		M_16_SWAP(hdrp->bitmaps[i]);
 	}
 }
 #endif

The Tor Browser / annotate

security/nss/lib/dbm/src/hash.c@6474c204b198 (annotated)

security/nss/lib/dbm/src/hash.c