1 files changed, 243 insertions, 0 deletions
diff --git a/source3/lib/username.c b/source3/lib/username.c
new file mode 100644
index 0000000..280285e
--- /dev/null
+++ b/source3/lib/username.c
@@ -0,0 +1,243 @@
+/* 
+   Unix SMB/CIFS implementation.
+   Username handling
+   Copyright (C) Andrew Tridgell 1992-1998
+   Copyright (C) Jeremy Allison 1997-2001.
+   Copyright (C) Andrew Bartlett 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/>.
+*/
+
+#include "includes.h"
+#include "system/passwd.h"
+#include "../lib/util/memcache.h"
+#include "../lib/util/util_pw.h"
+#include "lib/util/string_wrappers.h"
+
+/* internal functions */
+static struct passwd *uname_string_combinations(char *s, TALLOC_CTX *mem_ctx,
+						struct passwd * (*fn) (TALLOC_CTX *mem_ctx, const char *),
+						int N);
+static struct passwd *uname_string_combinations2(char *s, TALLOC_CTX *mem_ctx, int offset,
+						 struct passwd * (*fn) (TALLOC_CTX *mem_ctx, const char *),
+						 int N);
+
+static struct passwd *getpwnam_alloc_cached(TALLOC_CTX *mem_ctx, const char *name)
+{
+	struct passwd *pw, *for_cache;
+
+	pw = (struct passwd *)memcache_lookup_talloc(
+		NULL, GETPWNAM_CACHE, data_blob_string_const_null(name));
+	if (pw != NULL) {
+		return tcopy_passwd(mem_ctx, pw);
+	}
+
+	pw = getpwnam(name);
+	if (pw == NULL) {
+		return NULL;
+	}
+
+	for_cache = tcopy_passwd(talloc_tos(), pw);
+	if (for_cache == NULL) {
+		return NULL;
+	}
+
+	memcache_add_talloc(NULL, GETPWNAM_CACHE,
+			data_blob_string_const_null(name), &for_cache);
+
+	return tcopy_passwd(mem_ctx, pw);
+}
+
+/****************************************************************************
+ Flush all cached passwd structs.
+****************************************************************************/
+
+void flush_pwnam_cache(void)
+{
+        memcache_flush(NULL, GETPWNAM_CACHE);
+}
+
+/****************************************************************************
+ Get a users home directory.
+****************************************************************************/
+
+char *get_user_home_dir(TALLOC_CTX *mem_ctx, const char *user)
+{
+	struct passwd *pass;
+	char *result;
+
+	/* Ensure the user exists. */
+
+	pass = Get_Pwnam_alloc(mem_ctx, user);
+
+	if (!pass)
+		return(NULL);
+
+	/* Return home directory from struct passwd. */
+
+	result = talloc_move(mem_ctx, &pass->pw_dir);
+
+	TALLOC_FREE(pass);
+	return result;
+}
+
+/****************************************************************************
+ * A wrapper for getpwnam().  The following variations are tried:
+ *   - as transmitted
+ *   - in all lower case if this differs from transmitted
+ *   - in all upper case if this differs from transmitted
+ *   - using lp_username_level() for permutations.
+****************************************************************************/
+
+static struct passwd *Get_Pwnam_internals(TALLOC_CTX *mem_ctx,
+					  const char *user, char *user2)
+{
+	struct passwd *ret = NULL;
+
+	if (!user2 || !(*user2))
+		return(NULL);
+
+	if (!user || !(*user))
+		return(NULL);
+
+	/* Try in all lower case first as this is the most 
+	   common case on UNIX systems */
+	if (!strlower_m(user2)) {
+		DEBUG(5,("strlower_m %s failed\n", user2));
+		goto done;
+	}
+
+	DEBUG(5,("Trying _Get_Pwnam(), username as lowercase is %s\n",user2));
+	ret = getpwnam_alloc_cached(mem_ctx, user2);
+	if(ret)
+		goto done;
+
+	/* Try as given, if username wasn't originally lowercase */
+	if(strcmp(user, user2) != 0) {
+		DEBUG(5,("Trying _Get_Pwnam(), username as given is %s\n",
+			 user));
+		ret = getpwnam_alloc_cached(mem_ctx, user);
+		if(ret)
+			goto done;
+	}
+
+	/* Try as uppercase, if username wasn't originally uppercase */
+	if (!strupper_m(user2)) {
+		goto done;
+	}
+
+	if(strcmp(user, user2) != 0) {
+		DEBUG(5,("Trying _Get_Pwnam(), username as uppercase is %s\n",
+			 user2));
+		ret = getpwnam_alloc_cached(mem_ctx, user2);
+		if(ret)
+			goto done;
+	}
+
+	/* Try all combinations up to usernamelevel */
+	if (!strlower_m(user2)) {
+		DEBUG(5,("strlower_m %s failed\n", user2));
+		goto done;
+	}
+	DEBUG(5,("Checking combinations of %d uppercase letters in %s\n",
+		 lp_username_level(), user2));
+	ret = uname_string_combinations(user2, mem_ctx, getpwnam_alloc_cached,
+					lp_username_level());
+
+done:
+	DEBUG(5,("Get_Pwnam_internals %s find user [%s]!\n",ret ?
+		 "did":"didn't", user));
+
+	return ret;
+}
+
+/****************************************************************************
+ Get_Pwnam wrapper without modification.
+  NOTE: This with NOT modify 'user'! 
+  This will return an allocated structure
+****************************************************************************/
+
+struct passwd *Get_Pwnam_alloc(TALLOC_CTX *mem_ctx, const char *user)
+{
+	fstring user2;
+
+	if ( *user == '\0' ) {
+		DEBUG(10,("Get_Pwnam: empty username!\n"));
+		return NULL;
+	}
+
+	fstrcpy(user2, user);
+
+	DEBUG(5,("Finding user %s\n", user));
+
+	return Get_Pwnam_internals(mem_ctx, user, user2);
+}
+
+/* The functions below have been taken from password.c and slightly modified */
+/****************************************************************************
+ Apply a function to upper/lower case combinations
+ of a string and return true if one of them returns true.
+ Try all combinations with N uppercase letters.
+ offset is the first char to try and change (start with 0)
+ it assumes the string starts lowercased
+****************************************************************************/
+
+static struct passwd *uname_string_combinations2(char *s, TALLOC_CTX *mem_ctx,
+						 int offset,
+						 struct passwd *(*fn)(TALLOC_CTX *mem_ctx, const char *),
+						 int N)
+{
+	ssize_t len = (ssize_t)strlen(s);
+	int i;
+	struct passwd *ret;
+
+	if (N <= 0 || offset >= len)
+		return(fn(mem_ctx, s));
+
+	for (i=offset;i<(len-(N-1));i++) {
+		char c = s[i];
+		if (!islower_m((int)c))
+			continue;
+		s[i] = toupper_m(c);
+		ret = uname_string_combinations2(s, mem_ctx, i+1, fn, N-1);
+		if(ret)
+			return(ret);
+		s[i] = c;
+	}
+	return(NULL);
+}
+
+/****************************************************************************
+ Apply a function to upper/lower case combinations
+ of a string and return true if one of them returns true.
+ Try all combinations with up to N uppercase letters.
+ offset is the first char to try and change (start with 0)
+ it assumes the string starts lowercased
+****************************************************************************/
+
+static struct passwd * uname_string_combinations(char *s, TALLOC_CTX *mem_ctx,
+						 struct passwd * (*fn)(TALLOC_CTX *mem_ctx, const char *),
+						 int N)
+{
+	int n;
+	struct passwd *ret;
+
+	for (n=1;n<=N;n++) {
+		ret = uname_string_combinations2(s,mem_ctx,0,fn,n);
+		if(ret)
+			return(ret);
+	}  
+	return(NULL);
+}
+