/source3/lib/username.c
C | 232 lines | 129 code | 42 blank | 61 comment | 27 complexity | 98426b1196ccf6028c6d1e21273e2397 MD5 | raw file
Possible License(s): Apache-2.0, BSD-3-Clause, GPL-3.0, LGPL-2.1, LGPL-3.0
- /*
- 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);
- }