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/*
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 "memcache.h"
#include "../lib/util/util_pw.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 = sys_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 sys_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_usernamelevel() 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 */
strlower_m(user2);
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 */
strupper_m(user2);
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 */
strlower_m(user2);
DEBUG(5,("Checking combinations of %d uppercase letters in %s\n",
lp_usernamelevel(), user2));
ret = uname_string_combinations(user2, mem_ctx, getpwnam_alloc_cached,
lp_usernamelevel());
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);
}
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