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
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 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_POSSIBLE1 8
-#define FLAG_POSSIBLE2 16
-#define FLAG_POSSIBLE3 32
+#define FLAG_WILDCARD 8
-#define CACHE_SIZE 8192
+/* 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
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 */
-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 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 */
+ /* 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 = 0x238F13AF * length, i=0; i < length; i++) {
- value = (value + (((unsigned char)str[i]) << (i*5 % 24)));
- }
-
- return (1103515243 * value + 12345);
+ 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 the prefix cache
+ initialise (ie. allocate) the prefix cache
*/
static BOOL cache_init(void)
{
- if (prefix_cache) return True;
+ if (prefix_cache) {
+ return True;
+ }
- prefix_cache = malloc(sizeof(char *) * CACHE_SIZE);
- if (!prefix_cache) return False;
+ 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;
+ }
- memset(prefix_cache, 0, sizeof(char *) * CACHE_SIZE);
return True;
}
/*
- insert an entry into the prefix cache. The string may not be null terminated
-*/
+ 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 % CACHE_SIZE;
+ int i = hash % MANGLE_CACHE_SIZE;
if (prefix_cache[i]) {
free(prefix_cache[i]);
}
- prefix_cache[i] = strndup(prefix, length);
+ prefix_cache[i] = SMB_STRNDUP(prefix, length);
+ prefix_cache_hashes[i] = hash;
}
/*
*/
static const char *cache_lookup(u32 hash)
{
- int i = hash % CACHE_SIZE;
+ int i = hash % MANGLE_CACHE_SIZE;
- if (!prefix_cache[i]) return NULL;
-
- /* we have a possible match - compute the hash to confirm */
- if (hash != mangle_hash(prefix_cache[i], strlen(prefix_cache[i]))) {
+ if (!prefix_cache[i] || hash != prefix_cache_hashes[i]) {
return NULL;
}
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)
{
+ 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;
+ if (name[6] != '~')
+ return False;
/* check extension */
- /* check first character */
+ 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.
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, int snum)
{
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++) {
- if (!(char_flags[(unsigned)(name[i])] & FLAG_ASCII)) {
+ /* 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)
*/
-static BOOL check_cache(char *name)
+static BOOL check_cache(char *name, size_t maxlen, int snum)
{
u32 hash, multiplier;
- int i;
+ unsigned int i;
const char *prefix;
char extension[4];
/* make sure that this is a mangled name from this cache */
- if (!is_mangled(name)) {
+ 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>=1;i--) {
+ 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 */
- strncpy(extension, name+9, 3);
+ if (name[8] == '.') {
+ strncpy(extension, name+9, 3);
+ extension[3] = 0;
+ } else {
+ extension[0] = 0;
+ }
if (extension[0]) {
- slprintf(name, sizeof(fstring), "%s.%s", prefix, extension);
+ M_DEBUG(10,("check_cache: %s -> %s.%s\n", name, prefix, extension));
+ slprintf(name, maxlen, "%s.%s", prefix, extension);
} else {
- fstrcpy(name, prefix);
+ M_DEBUG(10,("check_cache: %s -> %s\n", name, prefix));
+ safe_strcpy(name, prefix, maxlen);
}
+
return True;
}
*/
static BOOL is_reserved_name(const char *name)
{
- if ((char_flags[(unsigned char)name[0]] & FLAG_POSSIBLE1) &&
- (char_flags[(unsigned char)name[1]] & FLAG_POSSIBLE2) &&
- (char_flags[(unsigned char)name[2]] & FLAG_POSSIBLE3)) {
+ 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 (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)
{
+ const char *dot_pos = NULL;
+ BOOL alldots = True;
+ size_t numdots = 0;
+
while (*name) {
- if (char_flags[(unsigned char)*name] & FLAG_ILLEGAL) {
+ 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 name parameter must be able to hold 13 bytes
*/
-static BOOL name_map(char *name, BOOL need83, BOOL cache83)
+static void name_map(fstring name, BOOL need83, BOOL cache83, int default_case, int snum)
{
char *dot_p;
- char lead_char;
+ char lead_chars[7];
char extension[4];
- int extension_length, i;
- int prefix_len;
+ unsigned int extension_length, i;
+ unsigned int prefix_len;
u32 hash, v;
char new_name[13];
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 (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 True;
+ return;
}
}
/* find the '.' if any */
- dot_p = strchr(name, '.');
+ 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 (! (char_flags[(unsigned char)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(lead_chars[i]);
+ }
+ for (;i<mangle_prefix;i++) {
+ lead_chars[i] = '_';
}
/* 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 (char_flags[(unsigned char)c] & FLAG_ASCII) {
- extension[extension_length++] = c;
+ if (FLAG_CHECK(c, FLAG_ASCII)) {
+ extension[extension_length++] = toupper(c);
}
}
}
/* find the hash for this prefix */
v = hash = mangle_hash(name, prefix_len);
- /* now form the mangled name */
- new_name[0] = lead_char;
+ /* 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>=1; i--) {
+ 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(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 */
- return True;
}
memset(char_flags, 0, sizeof(char_flags));
- for (i=0;i<128;i++) {
+ 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("._-$~", i)) {
+ if (strchr("_-$~", 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));
/* 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;
+ 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(c1)] |= FLAG_POSSIBLE1;
char_flags[tolower(c2)] |= FLAG_POSSIBLE2;
char_flags[tolower(c3)] |= FLAG_POSSIBLE3;
+ char_flags[tolower(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,
- mangle_reset,
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();
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;
+}
git.samba.org / samba.git / blobdiff