Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 875 insertions, 0 deletions

diff --git a/source3/smbd/mangle_hash2.c b/source3/smbd/mangle_hash2.c
new file mode 100644
index 0000000..a8cf352
--- /dev/null
+++ b/source3/smbd/mangle_hash2.c
@@ -0,0 +1,875 @@
+/* 
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+  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!!
+  ===============================================================================
+*/
+
+/*
+ * ============================================================================
+ * Whenever you change anything in the FLAG_ or other fields,
+ * re-initialize the tables char_flags and base_reverse by running the
+ * init_tables() routine once and dump its results. To do this, a
+ * single smbd run with
+ *
+ * #define DYNAMIC_MANGLE_TABLES 1
+ *
+ * and debug level 10 should be sufficient.
+ * ============================================================================
+ */
+
+
+#include "includes.h"
+#include "smbd/smbd.h"
+#include "smbd/globals.h"
+#include "../lib/util/memcache.h"
+#include "mangle.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
+
+#define FNV1_PRIME 0x01000193
+/*the following number is a fnv1 of the string: idra@samba.org 2002 */
+#define FNV1_INIT  0xa6b93095
+
+#define FLAG_CHECK(c, flag) (char_flags[(unsigned char)(c)] & (flag))
+
+/* these are the characters we use in the 8.3 hash. Must be 36 chars long */
+static const char basechars[36] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+#define base_forward(v) basechars[v]
+
+/* the list of reserved dos names - all of these are illegal */
+static const char * const reserved_names[] =
+{ "AUX", "CON",
+  "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9",
+  "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
+  "NUL", "PRN", NULL };
+
+#define DYNAMIC_MANGLE_TABLES 0
+
+#if DYNAMIC_MANGLE_TABLES
+
+/* these tables are used to provide fast tests for characters */
+static unsigned char char_flags[256];
+static unsigned char base_reverse[256];
+
+/* 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_m(c1)] |= FLAG_POSSIBLE1;
+		char_flags[tolower_m(c2)] |= FLAG_POSSIBLE2;
+		char_flags[tolower_m(c3)] |= FLAG_POSSIBLE3;
+		char_flags[tolower_m(c4)] |= FLAG_POSSIBLE4;
+
+		char_flags[(unsigned char)'.'] |= FLAG_POSSIBLE4;
+	}
+
+#if 0
+	DEBUG(10, ("char_flags\n"));
+	dump_data(10, char_flags, sizeof(char_flags));
+
+	DEBUG(10, ("base_reverse\n"));
+	dump_data(10, base_reverse, sizeof(base_reverse));
+#endif
+}
+
+#else /* DYNAMIC_MANGLE_TABLES */
+
+/*
+ * These tables were initialized by a single run of the above
+ * init_tables() routine, dumping the tables and a simple emacs macro.
+ *
+ * Technically we could leave out the 0's at the end of the array
+ * initializers, but I'll leave it in: less surprise.
+ */
+
+static const uint8_t char_flags[256] = {
+	0x80, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
+	0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
+	0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
+	0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
+	0x00, 0x00, 0x0C, 0x00, 0x02, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x0C, 0x00, 0x00, 0x02, 0x80, 0x04,
+	0x03, 0x83, 0x83, 0x83, 0x83, 0x03, 0x03, 0x03,
+	0x03, 0x03, 0x04, 0x00, 0x0C, 0x00, 0x0C, 0x0C,
+	0x00, 0x13, 0x03, 0x53, 0x03, 0x03, 0x03, 0x03,
+	0x03, 0x03, 0x03, 0x83, 0x53, 0x43, 0x53, 0x23,
+	0x33, 0x03, 0x23, 0x03, 0x43, 0x23, 0x03, 0x03,
+	0x43, 0x03, 0x03, 0x00, 0x04, 0x00, 0x00, 0x02,
+	0x00, 0x13, 0x03, 0x53, 0x03, 0x03, 0x03, 0x03,
+	0x03, 0x03, 0x03, 0x83, 0x53, 0x43, 0x53, 0x23,
+	0x33, 0x03, 0x23, 0x03, 0x43, 0x23, 0x03, 0x03,
+	0x43, 0x03, 0x03, 0x00, 0x04, 0x00, 0x02, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static const uint8_t base_reverse[256] = {
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+	0x08, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,
+	0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
+	0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
+	0x21, 0x22, 0x23, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+#endif /* DYNAMIC_MANGLE_TABLES */
+
+/* 
+   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 unsigned int mangle_hash(const char *key, unsigned int length)
+{
+	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;
+	(void)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 *= (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 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, unsigned int hash)
+{
+	char *str = SMB_STRNDUP(prefix, length);
+
+	if (str == NULL) {
+		return;
+	}
+
+	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 char *cache_lookup(TALLOC_CTX *mem_ctx, unsigned int hash)
+{
+	DATA_BLOB value;
+
+	if (!memcache_lookup(smbd_memcache(), MANGLE_HASH2_CACHE,
+			     data_blob_const(&hash, sizeof(hash)), &value)) {
+		return NULL;
+	}
+
+	SMB_ASSERT((value.length > 0)
+		   && (value.data[value.length-1] == '\0'));
+
+	return talloc_strdup(mem_ctx, (char *)value.data);
+}
+
+
+/* 
+   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, 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 to return to the client.
+   Note this is not testing if this is a valid Samba mangled name, so
+   the rules are different for is_mangled.
+
+   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 const char force_shortname_chars[] = " +,[];=";
+
+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;
+
+	/* as a special case, the names '.' and '..' are allowable 8.3 names */
+	if (ISDOT(name) || (ISDOTDOT(name))) {
+		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++) {
+		if (FLAG_CHECK(name[i], FLAG_ILLEGAL)) {
+			return false;
+		}
+		/* note that we may allow wildcard petterns! */
+		if (!allow_wildcards && FLAG_CHECK(name[i], FLAG_WILDCARD)) {
+			return false;
+		}
+		if (((unsigned char)name[i]) > 0x7e) {
+			return false;
+		}
+		if (strchr(force_shortname_chars, 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 lookup_name_from_8_3(TALLOC_CTX *ctx,
+			const char *name,
+			char **pp_out, /* talloced on the given context. */
+			const struct share_params *p)
+{
+	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, 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>=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(ctx, hash);
+	if (!prefix) {
+		M_DEBUG(10,("lookup_name_from_8_3: %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,("lookup_name_from_8_3: %s -> %s.%s\n",
+					name, prefix, extension));
+		*pp_out = talloc_asprintf(ctx, "%s.%s", prefix, extension);
+	} else {
+		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)
+{
+	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. */
+			size_t size = 0;
+			(void)next_codepoint(name, &size);
+			/*
+			 * Note that we're only looking for multibyte
+			 * encoding here. No encoding with a length > 1
+			 * contains invalid characters.
+			 */
+			if (size > 1) {
+				/* Was a mb string. */
+				name += size;
+				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 cache83 is not set then we don't cache the result
+
+*/
+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_chars[7];
+	char extension[4];
+	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
+		 * change anything */
+		if (is_legal_name(name) && is_8_3(name, False, False, p)) {
+			strlcpy(new_name, name, 13);
+			return True;
+		}
+	}
+
+	/* 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_m(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_m(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,("hash2_name_to_8_3: %s -> %08X -> %s (cache=%d)\n",
+		   name, hash, new_name, cache83));
+
+	return True;
+}
+
+/*
+  the following provides the abstraction layer to make it easier
+  to drop in an alternative mangling implementation */
+static const struct mangle_fns mangle_hash2_fns = {
+	mangle_reset,
+	is_mangled,
+	must_mangle,
+	is_8_3,
+	lookup_name_from_8_3,
+	hash2_name_to_8_3
+};
+
+/* return the methods for this mangling implementation */
+const 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;
+	}
+
+#if DYNAMIC_MANGLE_TABLES
+	init_tables();
+#endif
+	mangle_reset();
+
+	return &mangle_hash2_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 const 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
+};
+
+const struct mangle_fns *posix_mangle_init(void)
+{
+	return &posix_mangle_fns;
+}