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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
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.
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
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
+ */
/*
===============================================================================
#include "includes.h"
-#if 0
+#if 1
#define M_DEBUG(level, x) DEBUG(level, x)
#else
#define M_DEBUG(level, x)
#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))
-/* 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
+/*
+ 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 char **prefix_cache;
-static u32 *prefix_cache_hashes;
+static unsigned mangle_prefix;
/* these are the characters we use in the 8.3 hash. Must be 36 chars long */
-const char *basechars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+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 */
-const char *reserved_names[] = { "AUX", "LOCK$", "CON", "COM1", "COM2", "COM3", "COM4",
- "LPT1", "LPT2", "LPT3", "NUL", "PRN", NULL };
+static const char *reserved_names[] =
+{ "AUX", "LOCK$", "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
this hash needs to be fast with a low collision rate (what hash doesn't?)
*/
-static u32 mangle_hash(const char *key, unsigned length)
+static unsigned int mangle_hash(const char *key, unsigned int length)
{
- u32 value;
- u32 i;
+ unsigned int value;
+ unsigned int 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);
length = strlen(str);
/* Set the initial value from the key size. */
- for (value = 0x238F13AF * length, i=0; i < length; i++) {
- value = (value + (((unsigned char)str[i]) << (i*5 % 24)));
- }
+ for (value = FNV1_INIT, i=0; i < length; i++) {
+ value *= (unsigned int)FNV1_PRIME;
+ value ^= (unsigned int)(str[i]);
+ }
/* note that we force it to a 31 bit hash, to keep within the limits
of the 36^6 mangle space */
- return (1103515243 * value + 12345) & ~0x80000000;
-}
-
-/*
- initialise (ie. allocate) the prefix cache
- */
-static BOOL cache_init(void)
-{
- if (prefix_cache) return True;
-
- prefix_cache = malloc(sizeof(char *) * MANGLE_CACHE_SIZE);
- if (!prefix_cache) return False;
-
- prefix_cache_hashes = malloc(sizeof(u32) * MANGLE_CACHE_SIZE);
- if (!prefix_cache_hashes) return False;
-
- memset(prefix_cache, 0, sizeof(char *) * MANGLE_CACHE_SIZE);
- memset(prefix_cache_hashes, 0, sizeof(char *) * MANGLE_CACHE_SIZE);
- return True;
+ return value & ~0x80000000;
}
/*
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)
+static void cache_insert(const char *prefix, int length, unsigned int hash)
{
- int i = hash % MANGLE_CACHE_SIZE;
+ char *str = SMB_STRNDUP(prefix, length);
- if (prefix_cache[i]) {
- free(prefix_cache[i]);
+ if (str == NULL) {
+ return;
}
- prefix_cache[i] = strndup(prefix, length);
- prefix_cache_hashes[i] = hash;
+ memcache_add(smbd_memcache(), MANGLE_HASH2_CACHE,
+ data_blob_const(&hash, sizeof(hash)),
+ data_blob_const(str, length+1));
+ SAFE_FREE(str);
}
/*
lookup an entry in the prefix cache. Return NULL if not found.
*/
-static const char *cache_lookup(u32 hash)
+static char *cache_lookup(TALLOC_CTX *mem_ctx, unsigned int hash)
{
- int i = hash % MANGLE_CACHE_SIZE;
+ DATA_BLOB value;
- if (!prefix_cache[i] || hash != prefix_cache_hashes[i]) {
+ if (!memcache_lookup(smbd_memcache(), MANGLE_HASH2_CACHE,
+ data_blob_const(&hash, sizeof(hash)), &value)) {
return NULL;
}
- /* yep, it matched */
- return prefix_cache[i];
+ SMB_ASSERT((value.length > 0)
+ && (value.data[value.length-1] == '\0'));
+
+ return talloc_strdup(mem_ctx, (char *)value.data);
}
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(const char *name)
+ */
+static bool is_mangled_component(const char *name, size_t len)
{
- int len, i;
-
- M_DEBUG(0,("is_mangled %s ?\n", name));
+ unsigned int i;
- /* the best distinguishing characteristic is the ~ */
- if (name[6] != '~') return False;
+ M_DEBUG(10,("is_mangled_component %s (len %lu) ?\n", name, (unsigned long)len));
/* check the length */
- len = strlen(name);
- if (len > 12 || len < 8) return False;
+ 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++) {
+ if (name[8] != '.')
+ return False;
+ for (i=9; name[i] && i < len; i++) {
if (! FLAG_CHECK(name[i], FLAG_ASCII)) {
return False;
}
}
}
- /* check first character */
- if (! FLAG_CHECK(name[0], 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=1;i<6;i++) {
+ for (i=mangle_prefix;i<6;i++) {
if (! FLAG_CHECK(name[i], FLAG_BASECHAR)) {
return False;
}
}
- M_DEBUG(0,("is_mangled %s -> yes\n", name));
+ 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, const struct share_params *parm)
+{
+ 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.
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)
+static bool is_8_3(const char *name, bool check_case, bool allow_wildcards, const struct share_params *p)
{
int len, i;
char *dot_p;
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;
+ if (len > 12)
+ return False;
/* find the '.'. Note that once again we use the non-multibyte
function */
prefix_len = PTR_DIFF(dot_p, name);
suffix_len = len - (prefix_len+1);
- if (prefix_len > 8 || suffix_len > 3) {
+ if (prefix_len > 8 || suffix_len > 3 || suffix_len == 0) {
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 allow wildcard petterns! */
- if (!FLAG_CHECK(name[i], FLAG_ASCII|FLAG_WILDCARD) && name[i] != '.') {
+ /* note that we may allow wildcard petterns! */
+ if (!FLAG_CHECK(name[i], FLAG_ASCII|(allow_wildcards ? FLAG_WILDCARD : 0)) && name[i] != '.') {
return False;
}
}
/*
try to find a 8.3 name in the cache, and if found then
- replace the string with the original long name.
-
- The filename must be able to hold at least sizeof(fstring)
+ replace the string with the original long name.
*/
-static BOOL check_cache(char *name)
+static bool lookup_name_from_8_3(TALLOC_CTX *ctx,
+ const char *name,
+ char **pp_out, /* talloced on the given context. */
+ const struct share_params *p)
{
- u32 hash, multiplier;
- int i;
- const char *prefix;
+ unsigned int hash, multiplier;
+ unsigned int i;
+ char *prefix;
char extension[4];
+ *pp_out = NULL;
+
/* make sure that this is a mangled name from this cache */
- if (!is_mangled(name)) {
- M_DEBUG(0,("check_cache: %s -> not mangled\n", name));
+ if (!is_mangled(name, p)) {
+ M_DEBUG(10,("lookup_name_from_8_3: %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>=1;i--) {
- u32 v = base_reverse[(unsigned char)name[i]];
+ for (multiplier=36, i=5;i>=mangle_prefix;i--) {
+ unsigned int 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);
+ prefix = cache_lookup(ctx, hash);
if (!prefix) {
- M_DEBUG(0,("check_cache: %s -> %08X -> not found\n", name, hash));
+ M_DEBUG(10,("lookup_name_from_8_3: %s -> %08X -> not found\n",
+ name, hash));
return False;
}
/* we found it - construct the full name */
- strncpy(extension, name+9, 3);
+ if (name[8] == '.') {
+ strncpy(extension, name+9, 3);
+ extension[3] = 0;
+ } else {
+ extension[0] = 0;
+ }
if (extension[0]) {
- M_DEBUG(0,("check_cache: %s -> %s.%s\n", name, prefix, extension));
- slprintf(name, sizeof(fstring), "%s.%s", prefix, extension);
+ M_DEBUG(10,("lookup_name_from_8_3: %s -> %s.%s\n",
+ name, prefix, extension));
+ *pp_out = talloc_asprintf(ctx, "%s.%s", prefix, extension);
} else {
- M_DEBUG(0,("check_cache: %s -> %s\n", name, prefix));
- fstrcpy(name, prefix);
+ M_DEBUG(10,("lookup_name_from_8_3: %s -> %s\n", name, prefix));
+ *pp_out = talloc_strdup(ctx, prefix);
+ }
+
+ TALLOC_FREE(prefix);
+
+ if (!*pp_out) {
+ M_DEBUG(0,("talloc_fail"));
+ return False;
}
return True;
}
-
/*
look for a DOS reserved name
*/
-static BOOL is_reserved_name(const char *name)
+static bool is_reserved_name(const char *name)
{
if (FLAG_CHECK(name[0], FLAG_POSSIBLE1) &&
FLAG_CHECK(name[1], FLAG_POSSIBLE2) &&
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 (strncasecmp(name, reserved_names[i], len) == 0 &&
+ if (strnequal(name, reserved_names[i], len) &&
(name[len] == '.' || name[len] == 0)) {
return True;
}
}
/*
- see if a filename is a legal long filename
+ 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)
+
+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_UTF16LE, 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;
}
+static bool must_mangle(const char *name,
+ const struct share_params *p)
+{
+ if (is_reserved_name(name)) {
+ return True;
+ }
+ return !is_legal_name(name);
+}
+
/*
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 BOOL name_map(char *name, BOOL need83, BOOL cache83)
+static bool hash2_name_to_8_3(const char *name,
+ char new_name[13],
+ bool cache83,
+ int default_case,
+ const struct share_params *p)
{
char *dot_p;
- char lead_char;
+ char lead_chars[7];
char extension[4];
- int extension_length, i;
- int prefix_len;
- u32 hash, v;
- char new_name[13];
+ unsigned int extension_length, i;
+ unsigned int prefix_len;
+ unsigned int hash, v;
/* 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)) {
- return True;
- }
-
- /* if the caller doesn't strictly need 8.3 then just check for illegal
- filenames */
- if (!need83 && is_legal_name(name)) {
+ /* if the name is already a valid 8.3 name then we don't need to
+ * change anything */
+ if (is_legal_name(name) && is_8_3(name, False, False, p)) {
+ safe_strcpy(new_name, name, 12);
return True;
}
}
/* find the '.' if any */
dot_p = strrchr(name, '.');
- /* the leading character in the mangled name is taken from
- the first character of the name, if it is ascii
- otherwise '_' is used
+ 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
*/
- lead_char = name[0];
- if (! FLAG_CHECK(lead_char, FLAG_ASCII)) {
- lead_char = '_';
+ 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] = '_';
}
- lead_char = toupper(lead_char);
/* the prefix is anything up to the first dot */
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(c);
+ extension[extension_length++] =
+ toupper_ascii(c);
}
}
}
-
+
/* find the hash for this prefix */
v = hash = mangle_hash(name, prefix_len);
/* now form the mangled name. */
- new_name[0] = lead_char;
+ 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>=1; i--) {
+ new_name[6] = '~';
+ for (i=5; i>=mangle_prefix; i--) {
v = v / 36;
new_name[i] = base_forward(v % 36);
}
cache_insert(name, prefix_len, hash);
}
- M_DEBUG(0,("name_map: %s -> %08X -> %s (cache=%d)\n",
+ M_DEBUG(10,("hash2_name_to_8_3: %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 */
return True;
}
-
-/* initialise the flags table
+/* 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.
+ restrictions.
*/
static void init_tables(void)
{
memset(char_flags, 0, sizeof(char_flags));
- for (i=0;i<128;i++) {
- if ((i >= '0' && i <= '9') ||
- (i >= 'a' && i <= 'z') ||
+ 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);
}
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 */
char_flags[c2] |= FLAG_POSSIBLE2;
char_flags[c3] |= FLAG_POSSIBLE3;
char_flags[c4] |= FLAG_POSSIBLE4;
- char_flags[tolower(c1)] |= FLAG_POSSIBLE1;
- char_flags[tolower(c2)] |= FLAG_POSSIBLE2;
- char_flags[tolower(c3)] |= FLAG_POSSIBLE3;
- char_flags[tolower(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,
+ must_mangle,
is_8_3,
- mangle_reset,
- check_cache,
- name_map
+ lookup_name_from_8_3,
+ hash2_name_to_8_3
};
/* 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, const struct share_params *p)
+{
+ return False;
+}
+
+static bool posix_must_mangle(const char *s, const struct share_params *p)
+{
+ return False;
+}
+
+static bool posix_is_8_3(const char *fname,
+ bool check_case,
+ bool allow_wildcards,
+ const struct share_params *p)
+{
+ return False;
+}
+
+static bool posix_lookup_name_from_8_3(TALLOC_CTX *ctx,
+ const char *in,
+ char **out, /* talloced on the given context. */
+ const struct share_params *p)
+{
+ return False;
+}
+
+static bool posix_name_to_8_3(const char *in,
+ char out[13],
+ bool cache83,
+ int default_case,
+ const struct share_params *p)
+{
+ memset(out, '\0', 13);
+ return True;
+}
+
+/* POSIX paths backend - no mangle. */
+static struct mangle_fns posix_mangle_fns = {
+ posix_mangle_reset,
+ posix_is_mangled,
+ posix_must_mangle,
+ posix_is_8_3,
+ posix_lookup_name_from_8_3,
+ posix_name_to_8_3
+};
+
+struct mangle_fns *posix_mangle_init(void)
+{
+ return &posix_mangle_fns;
+}
git.samba.org / samba.git / blobdiff