--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+ new hash based name mangling implementation
+ Copyright (C) Andrew Tridgell 2002
+ Copyright (C) Simo Sorce 2002
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/*
+ this mangling scheme uses the following format
+
+ Annnn~n.AAA
+
+ where nnnnn is a base 36 hash, and A represents characters from the original string
+
+ The hash is taken of the leading part of the long filename, in uppercase
+
+ for simplicity, we only allow ascii characters in 8.3 names
+ */
+
+ /* hash alghorithm changed to FNV1 by idra@samba.org (Simo Sorce).
+ * see http://www.isthe.com/chongo/tech/comp/fnv/index.html for a
+ * discussion on Fowler / Noll / Vo (FNV) Hash by one of it's authors
+ */
+
+/*
+ ===============================================================================
+ NOTE NOTE NOTE!!!
+
+ This file deliberately uses non-multibyte string functions in many places. This
+ is *not* a mistake. This code is multi-byte safe, but it gets this property
+ through some very subtle knowledge of the way multi-byte strings are encoded
+ and the fact that this mangling algorithm only supports ascii characters in
+ 8.3 names.
+
+ please don't convert this file to use the *_m() functions!!
+ ===============================================================================
+*/
+
+
+#include "includes.h"
+
+#if 1
+#define M_DEBUG(level, x) DEBUG(level, x)
+#else
+#define M_DEBUG(level, x)
+#endif
+
+/* these flags are used to mark characters in as having particular
+ properties */
+#define FLAG_BASECHAR 1
+#define FLAG_ASCII 2
+#define FLAG_ILLEGAL 4
+#define FLAG_WILDCARD 8
+
+/* the "possible" flags are used as a fast way to find possible DOS
+ reserved filenames */
+#define FLAG_POSSIBLE1 16
+#define FLAG_POSSIBLE2 32
+#define FLAG_POSSIBLE3 64
+#define FLAG_POSSIBLE4 128
+
+/* by default have a max of 4096 entries in the cache. */
+#ifndef MANGLE_CACHE_SIZE
+#define MANGLE_CACHE_SIZE 4096
+#endif
+
+#define FNV1_PRIME 0x01000193
+/*the following number is a fnv1 of the string: idra@samba.org 2002 */
+#define FNV1_INIT 0xa6b93095
+
+/* these tables are used to provide fast tests for characters */
+static unsigned char char_flags[256];
+
+#define FLAG_CHECK(c, flag) (char_flags[(unsigned char)(c)] & (flag))
+
+/*
+ this determines how many characters are used from the original filename
+ in the 8.3 mangled name. A larger value leads to a weaker hash and more collisions.
+ The largest possible value is 6.
+*/
+static unsigned mangle_prefix;
+
+/* we will use a very simple direct mapped prefix cache. The big
+ advantage of this cache structure is speed and low memory usage
+
+ The cache is indexed by the low-order bits of the hash, and confirmed by
+ hashing the resulting cache entry to match the known hash
+*/
+static char **prefix_cache;
+static u32 *prefix_cache_hashes;
+
+/* these are the characters we use in the 8.3 hash. Must be 36 chars long */
+static const char *basechars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+static unsigned char base_reverse[256];
+#define base_forward(v) basechars[v]
+
+/* the list of reserved dos names - all of these are illegal */
+static const char *reserved_names[] =
+{ "AUX", "LOCK$", "CON", "COM1", "COM2", "COM3", "COM4",
+ "LPT1", "LPT2", "LPT3", "NUL", "PRN", NULL };
+
+/*
+ hash a string of the specified length. The string does not need to be
+ null terminated
+
+ this hash needs to be fast with a low collision rate (what hash doesn't?)
+*/
+static u32 mangle_hash(const char *key, unsigned int length)
+{
+ u32 value;
+ u32 i;
+ fstring str;
+
+ /* we have to uppercase here to ensure that the mangled name
+ doesn't depend on the case of the long name. Note that this
+ is the only place where we need to use a multi-byte string
+ function */
+ length = MIN(length,sizeof(fstring)-1);
+ strncpy(str, key, length);
+ str[length] = 0;
+ strupper_m(str);
+
+ /* the length of a multi-byte string can change after a strupper_m */
+ length = strlen(str);
+
+ /* Set the initial value from the key size. */
+ for (value = FNV1_INIT, i=0; i < length; i++) {
+ value *= (u32)FNV1_PRIME;
+ value ^= (u32)(str[i]);
+ }
+
+ /* note that we force it to a 31 bit hash, to keep within the limits
+ of the 36^6 mangle space */
+ return value & ~0x80000000;
+}
+
+/*
+ initialise (ie. allocate) the prefix cache
+ */
+static BOOL cache_init(void)
+{
+ if (prefix_cache) {
+ return True;
+ }
+
+ prefix_cache = SMB_CALLOC_ARRAY(char *,MANGLE_CACHE_SIZE);
+ if (!prefix_cache) {
+ return False;
+ }
+
+ prefix_cache_hashes = SMB_CALLOC_ARRAY(u32, MANGLE_CACHE_SIZE);
+ if (!prefix_cache_hashes) {
+ return False;
+ }
+
+ return True;
+}
+
+/*
+ insert an entry into the prefix cache. The string might not be null
+ terminated */
+static void cache_insert(const char *prefix, int length, u32 hash)
+{
+ int i = hash % MANGLE_CACHE_SIZE;
+
+ if (prefix_cache[i]) {
+ free(prefix_cache[i]);
+ }
+
+ prefix_cache[i] = SMB_STRNDUP(prefix, length);
+ prefix_cache_hashes[i] = hash;
+}
+
+/*
+ lookup an entry in the prefix cache. Return NULL if not found.
+*/
+static const char *cache_lookup(u32 hash)
+{
+ int i = hash % MANGLE_CACHE_SIZE;
+
+ if (!prefix_cache[i] || hash != prefix_cache_hashes[i]) {
+ return NULL;
+ }
+
+ /* yep, it matched */
+ return prefix_cache[i];
+}
+
+
+/*
+ determine if a string is possibly in a mangled format, ignoring
+ case
+
+ In this algorithm, mangled names use only pure ascii characters (no
+ multi-byte) so we can avoid doing a UCS2 conversion
+ */
+static BOOL is_mangled_component(const char *name, size_t len)
+{
+ unsigned int i;
+
+ M_DEBUG(10,("is_mangled_component %s (len %lu) ?\n", name, (unsigned long)len));
+
+ /* check the length */
+ if (len > 12 || len < 8)
+ return False;
+
+ /* the best distinguishing characteristic is the ~ */
+ if (name[6] != '~')
+ return False;
+
+ /* check extension */
+ if (len > 8) {
+ if (name[8] != '.')
+ return False;
+ for (i=9; name[i] && i < len; i++) {
+ if (! FLAG_CHECK(name[i], FLAG_ASCII)) {
+ return False;
+ }
+ }
+ }
+
+ /* check lead characters */
+ for (i=0;i<mangle_prefix;i++) {
+ if (! FLAG_CHECK(name[i], FLAG_ASCII)) {
+ return False;
+ }
+ }
+
+ /* check rest of hash */
+ if (! FLAG_CHECK(name[7], FLAG_BASECHAR)) {
+ return False;
+ }
+ for (i=mangle_prefix;i<6;i++) {
+ if (! FLAG_CHECK(name[i], FLAG_BASECHAR)) {
+ return False;
+ }
+ }
+
+ M_DEBUG(10,("is_mangled_component %s (len %lu) -> yes\n", name, (unsigned long)len));
+
+ return True;
+}
+
+
+
+/*
+ determine if a string is possibly in a mangled format, ignoring
+ case
+
+ In this algorithm, mangled names use only pure ascii characters (no
+ multi-byte) so we can avoid doing a UCS2 conversion
+
+ NOTE! This interface must be able to handle a path with unix
+ directory separators. It should return true if any component is
+ mangled
+ */
+static BOOL is_mangled(const char *name, int snum)
+{
+ const char *p;
+ const char *s;
+
+ M_DEBUG(10,("is_mangled %s ?\n", name));
+
+ for (s=name; (p=strchr(s, '/')); s=p+1) {
+ if (is_mangled_component(s, PTR_DIFF(p, s))) {
+ return True;
+ }
+ }
+
+ /* and the last part ... */
+ return is_mangled_component(s,strlen(s));
+}
+
+
+/*
+ see if a filename is an allowable 8.3 name.
+
+ we are only going to allow ascii characters in 8.3 names, as this
+ simplifies things greatly (it means that we know the string won't
+ get larger when converted from UNIX to DOS formats)
+*/
+static BOOL is_8_3(const char *name, BOOL check_case, BOOL allow_wildcards, int snum)
+{
+ int len, i;
+ char *dot_p;
+
+ /* as a special case, the names '.' and '..' are allowable 8.3 names */
+ if (name[0] == '.') {
+ if (!name[1] || (name[1] == '.' && !name[2])) {
+ return True;
+ }
+ }
+
+ /* the simplest test is on the overall length of the
+ filename. Note that we deliberately use the ascii string
+ length (not the multi-byte one) as it is faster, and gives us
+ the result we need in this case. Using strlen_m would not
+ only be slower, it would be incorrect */
+ len = strlen(name);
+ if (len > 12)
+ return False;
+
+ /* find the '.'. Note that once again we use the non-multibyte
+ function */
+ dot_p = strchr(name, '.');
+
+ if (!dot_p) {
+ /* if the name doesn't contain a '.' then its length
+ must be less than 8 */
+ if (len > 8) {
+ return False;
+ }
+ } else {
+ int prefix_len, suffix_len;
+
+ /* if it does contain a dot then the prefix must be <=
+ 8 and the suffix <= 3 in length */
+ prefix_len = PTR_DIFF(dot_p, name);
+ suffix_len = len - (prefix_len+1);
+
+ if (prefix_len > 8 || suffix_len > 3 || suffix_len == 0) {
+ return False;
+ }
+
+ /* a 8.3 name cannot contain more than 1 '.' */
+ if (strchr(dot_p+1, '.')) {
+ return False;
+ }
+ }
+
+ /* the length are all OK. Now check to see if the characters themselves are OK */
+ for (i=0; name[i]; i++) {
+ /* note that we may allow wildcard petterns! */
+ if (!FLAG_CHECK(name[i], FLAG_ASCII|(allow_wildcards ? FLAG_WILDCARD : 0)) && name[i] != '.') {
+ return False;
+ }
+ }
+
+ /* it is a good 8.3 name */
+ return True;
+}
+
+
+/*
+ reset the mangling cache on a smb.conf reload. This only really makes sense for
+ mangling backends that have parameters in smb.conf, and as this backend doesn't
+ this is a NULL operation
+*/
+static void mangle_reset(void)
+{
+ /* noop */
+}
+
+
+/*
+ try to find a 8.3 name in the cache, and if found then
+ replace the string with the original long name.
+*/
+static BOOL check_cache(char *name, size_t maxlen, int snum)
+{
+ u32 hash, multiplier;
+ unsigned int i;
+ const char *prefix;
+ char extension[4];
+
+ /* make sure that this is a mangled name from this cache */
+ if (!is_mangled(name, snum)) {
+ M_DEBUG(10,("check_cache: %s -> not mangled\n", name));
+ return False;
+ }
+
+ /* we need to extract the hash from the 8.3 name */
+ hash = base_reverse[(unsigned char)name[7]];
+ for (multiplier=36, i=5;i>=mangle_prefix;i--) {
+ u32 v = base_reverse[(unsigned char)name[i]];
+ hash += multiplier * v;
+ multiplier *= 36;
+ }
+
+ /* now look in the prefix cache for that hash */
+ prefix = cache_lookup(hash);
+ if (!prefix) {
+ M_DEBUG(10,("check_cache: %s -> %08X -> not found\n", name, hash));
+ return False;
+ }
+
+ /* we found it - construct the full name */
+ if (name[8] == '.') {
+ strncpy(extension, name+9, 3);
+ extension[3] = 0;
+ } else {
+ extension[0] = 0;
+ }
+
+ if (extension[0]) {
+ M_DEBUG(10,("check_cache: %s -> %s.%s\n", name, prefix, extension));
+ slprintf(name, maxlen, "%s.%s", prefix, extension);
+ } else {
+ M_DEBUG(10,("check_cache: %s -> %s\n", name, prefix));
+ safe_strcpy(name, prefix, maxlen);
+ }
+
+ return True;
+}
+
+
+/*
+ look for a DOS reserved name
+*/
+static BOOL is_reserved_name(const char *name)
+{
+ if (FLAG_CHECK(name[0], FLAG_POSSIBLE1) &&
+ FLAG_CHECK(name[1], FLAG_POSSIBLE2) &&
+ FLAG_CHECK(name[2], FLAG_POSSIBLE3) &&
+ FLAG_CHECK(name[3], FLAG_POSSIBLE4)) {
+ /* a likely match, scan the lot */
+ int i;
+ for (i=0; reserved_names[i]; i++) {
+ int len = strlen(reserved_names[i]);
+ /* note that we match on COM1 as well as COM1.foo */
+ if (strnequal(name, reserved_names[i], len) &&
+ (name[len] == '.' || name[len] == 0)) {
+ return True;
+ }
+ }
+ }
+
+ return False;
+}
+
+/*
+ See if a filename is a legal long filename.
+ A filename ending in a '.' is not legal unless it's "." or "..". JRA.
+ A filename ending in ' ' is not legal either. See bug id #2769.
+*/
+
+static BOOL is_legal_name(const char *name)
+{
+ const char *dot_pos = NULL;
+ BOOL alldots = True;
+ size_t numdots = 0;
+
+ while (*name) {
+ if (((unsigned int)name[0]) > 128 && (name[1] != 0)) {
+ /* Possible start of mb character. */
+ char mbc[2];
+ /*
+ * Note that if CH_UNIX is utf8 a string may be 3
+ * bytes, but this is ok as mb utf8 characters don't
+ * contain embedded ascii bytes. We are really checking
+ * for mb UNIX asian characters like Japanese (SJIS) here.
+ * JRA.
+ */
+ if (convert_string(CH_UNIX, CH_UCS2, name, 2, mbc, 2, False) == 2) {
+ /* Was a good mb string. */
+ name += 2;
+ continue;
+ }
+ }
+
+ if (FLAG_CHECK(name[0], FLAG_ILLEGAL)) {
+ return False;
+ }
+ if (name[0] == '.') {
+ dot_pos = name;
+ numdots++;
+ } else {
+ alldots = False;
+ }
+ if ((name[0] == ' ') && (name[1] == '\0')) {
+ /* Can't end in ' ' */
+ return False;
+ }
+ name++;
+ }
+
+ if (dot_pos) {
+ if (alldots && (numdots == 1 || numdots == 2))
+ return True; /* . or .. is a valid name */
+
+ /* A valid long name cannot end in '.' */
+ if (dot_pos[1] == '\0')
+ return False;
+ }
+ return True;
+}
+
+/*
+ the main forward mapping function, which converts a long filename to
+ a 8.3 name
+
+ if need83 is not set then we only do the mangling if the name is illegal
+ as a long name
+
+ if cache83 is not set then we don't cache the result
+
+ the name parameter must be able to hold 13 bytes
+*/
+static void name_map(fstring name, BOOL need83, BOOL cache83, int default_case, int snum)
+{
+ char *dot_p;
+ char lead_chars[7];
+ char extension[4];
+ unsigned int extension_length, i;
+ unsigned int prefix_len;
+ u32 hash, v;
+ char new_name[13];
+
+ /* reserved names are handled specially */
+ if (!is_reserved_name(name)) {
+ /* if the name is already a valid 8.3 name then we don't need to
+ do anything */
+ if (is_8_3(name, False, False, snum)) {
+ return;
+ }
+
+ /* if the caller doesn't strictly need 8.3 then just check for illegal
+ filenames */
+ if (!need83 && is_legal_name(name)) {
+ return;
+ }
+ }
+
+ /* find the '.' if any */
+ dot_p = strrchr(name, '.');
+
+ if (dot_p) {
+ /* if the extension contains any illegal characters or
+ is too long or zero length then we treat it as part
+ of the prefix */
+ for (i=0; i<4 && dot_p[i+1]; i++) {
+ if (! FLAG_CHECK(dot_p[i+1], FLAG_ASCII)) {
+ dot_p = NULL;
+ break;
+ }
+ }
+ if (i == 0 || i == 4) dot_p = NULL;
+ }
+
+ /* the leading characters in the mangled name is taken from
+ the first characters of the name, if they are ascii otherwise
+ '_' is used
+ */
+ for (i=0;i<mangle_prefix && name[i];i++) {
+ lead_chars[i] = name[i];
+ if (! FLAG_CHECK(lead_chars[i], FLAG_ASCII)) {
+ lead_chars[i] = '_';
+ }
+ lead_chars[i] = toupper_ascii(lead_chars[i]);
+ }
+ for (;i<mangle_prefix;i++) {
+ lead_chars[i] = '_';
+ }
+
+ /* the prefix is anything up to the first dot */
+ if (dot_p) {
+ prefix_len = PTR_DIFF(dot_p, name);
+ } else {
+ prefix_len = strlen(name);
+ }
+
+ /* the extension of the mangled name is taken from the first 3
+ ascii chars after the dot */
+ extension_length = 0;
+ if (dot_p) {
+ for (i=1; extension_length < 3 && dot_p[i]; i++) {
+ char c = dot_p[i];
+ if (FLAG_CHECK(c, FLAG_ASCII)) {
+ extension[extension_length++] = toupper_ascii(c);
+ }
+ }
+ }
+
+ /* find the hash for this prefix */
+ v = hash = mangle_hash(name, prefix_len);
+
+ /* now form the mangled name. */
+ for (i=0;i<mangle_prefix;i++) {
+ new_name[i] = lead_chars[i];
+ }
+ new_name[7] = base_forward(v % 36);
+ new_name[6] = '~';
+ for (i=5; i>=mangle_prefix; i--) {
+ v = v / 36;
+ new_name[i] = base_forward(v % 36);
+ }
+
+ /* add the extension */
+ if (extension_length) {
+ new_name[8] = '.';
+ memcpy(&new_name[9], extension, extension_length);
+ new_name[9+extension_length] = 0;
+ } else {
+ new_name[8] = 0;
+ }
+
+ if (cache83) {
+ /* put it in the cache */
+ cache_insert(name, prefix_len, hash);
+ }
+
+ M_DEBUG(10,("name_map: %s -> %08X -> %s (cache=%d)\n",
+ name, hash, new_name, cache83));
+
+ /* and overwrite the old name */
+ fstrcpy(name, new_name);
+
+ /* all done, we've managed to mangle it */
+}
+
+
+/* initialise the flags table
+
+ we allow only a very restricted set of characters as 'ascii' in this
+ mangling backend. This isn't a significant problem as modern clients
+ use the 'long' filenames anyway, and those don't have these
+ restrictions.
+*/
+static void init_tables(void)
+{
+ int i;
+
+ memset(char_flags, 0, sizeof(char_flags));
+
+ for (i=1;i<128;i++) {
+ if (i <= 0x1f) {
+ /* Control characters. */
+ char_flags[i] |= FLAG_ILLEGAL;
+ }
+
+ if ((i >= '0' && i <= '9') ||
+ (i >= 'a' && i <= 'z') ||
+ (i >= 'A' && i <= 'Z')) {
+ char_flags[i] |= (FLAG_ASCII | FLAG_BASECHAR);
+ }
+ if (strchr("_-$~", i)) {
+ char_flags[i] |= FLAG_ASCII;
+ }
+
+ if (strchr("*\\/?<>|\":", i)) {
+ char_flags[i] |= FLAG_ILLEGAL;
+ }
+
+ if (strchr("*?\"<>", i)) {
+ char_flags[i] |= FLAG_WILDCARD;
+ }
+ }
+
+ memset(base_reverse, 0, sizeof(base_reverse));
+ for (i=0;i<36;i++) {
+ base_reverse[(unsigned char)base_forward(i)] = i;
+ }
+
+ /* fill in the reserved names flags. These are used as a very
+ fast filter for finding possible DOS reserved filenames */
+ for (i=0; reserved_names[i]; i++) {
+ unsigned char c1, c2, c3, c4;
+
+ c1 = (unsigned char)reserved_names[i][0];
+ c2 = (unsigned char)reserved_names[i][1];
+ c3 = (unsigned char)reserved_names[i][2];
+ c4 = (unsigned char)reserved_names[i][3];
+
+ char_flags[c1] |= FLAG_POSSIBLE1;
+ char_flags[c2] |= FLAG_POSSIBLE2;
+ char_flags[c3] |= FLAG_POSSIBLE3;
+ char_flags[c4] |= FLAG_POSSIBLE4;
+ char_flags[tolower_ascii(c1)] |= FLAG_POSSIBLE1;
+ char_flags[tolower_ascii(c2)] |= FLAG_POSSIBLE2;
+ char_flags[tolower_ascii(c3)] |= FLAG_POSSIBLE3;
+ char_flags[tolower_ascii(c4)] |= FLAG_POSSIBLE4;
+
+ char_flags[(unsigned char)'.'] |= FLAG_POSSIBLE4;
+ }
+}
+
+/*
+ the following provides the abstraction layer to make it easier
+ to drop in an alternative mangling implementation */
+static struct mangle_fns mangle_fns = {
+ mangle_reset,
+ is_mangled,
+ is_8_3,
+ check_cache,
+ name_map
+};
+
+/* return the methods for this mangling implementation */
+struct mangle_fns *mangle_hash2_init(void)
+{
+ /* the mangle prefix can only be in the mange 1 to 6 */
+ mangle_prefix = lp_mangle_prefix();
+ if (mangle_prefix > 6) {
+ mangle_prefix = 6;
+ }
+ if (mangle_prefix < 1) {
+ mangle_prefix = 1;
+ }
+
+ init_tables();
+ mangle_reset();
+
+ if (!cache_init()) {
+ return NULL;
+ }
+
+ return &mangle_fns;
+}
+
+static void posix_mangle_reset(void)
+{;}
+
+static BOOL posix_is_mangled(const char *s, int snum)
+{
+ return False;
+}
+
+static BOOL posix_is_8_3(const char *fname, BOOL check_case, BOOL allow_wildcards, int snum)
+{
+ return False;
+}
+
+static BOOL posix_check_cache( char *s, size_t maxlen, int snum )
+{
+ return False;
+}
+
+static void posix_name_map(char *OutName, BOOL need83, BOOL cache83, int default_case, int snum)
+{
+ if (need83) {
+ memset(OutName, '\0', 13);
+ }
+}
+
+/* POSIX paths backend - no mangle. */
+static struct mangle_fns posix_mangle_fns = {
+ posix_mangle_reset,
+ posix_is_mangled,
+ posix_is_8_3,
+ posix_check_cache,
+ posix_name_map
+};
+
+struct mangle_fns *posix_mangle_init(void)
+{
+ return &posix_mangle_fns;
+}
projects / samba / blobdiff