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Diffstat (limited to 'source3/smbd/mangle_hash2.c')
-rw-r--r--source3/smbd/mangle_hash2.c57
1 files changed, 41 insertions, 16 deletions
diff --git a/source3/smbd/mangle_hash2.c b/source3/smbd/mangle_hash2.c
index 5adde19eea..bbc9020eab 100644
--- a/source3/smbd/mangle_hash2.c
+++ b/source3/smbd/mangle_hash2.c
@@ -87,6 +87,13 @@ 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
@@ -217,16 +224,18 @@ static BOOL is_mangled_component(const char *name)
}
}
- /* 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;
}
@@ -371,7 +380,7 @@ static BOOL check_cache(char *name)
/* 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;
@@ -478,7 +487,7 @@ static BOOL is_legal_name(const char *name)
static void name_map(char *name, BOOL need83, BOOL cache83)
{
char *dot_p;
- char lead_char;
+ char lead_chars[7];
char extension[4];
int extension_length, i;
int prefix_len;
@@ -516,15 +525,20 @@ static void name_map(char *name, BOOL need83, BOOL cache83)
if (i == 0 || i == 4) dot_p = NULL;
}
- /* the leading character in the mangled name is taken from
- the first character of the name, if it is ascii
- otherwise '_' is used
+ /* 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(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) {
@@ -549,10 +563,12 @@ static void name_map(char *name, BOOL need83, BOOL cache83)
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--) {
+ for (i=5; i>=mangle_prefix; i--) {
v = v / 36;
new_name[i] = base_forward(v % 36);
}
@@ -594,7 +610,7 @@ static void init_tables(void)
memset(char_flags, 0, sizeof(char_flags));
- for (i=0;i<128;i++) {
+ for (i=1;i<128;i++) {
if ((i >= '0' && i <= '9') ||
(i >= 'a' && i <= 'z') ||
(i >= 'A' && i <= 'Z')) {
@@ -656,6 +672,15 @@ static struct mangle_fns mangle_fns = {
/* 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();