/* 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_ascii((int)c)) continue; s[i] = toupper_ascii(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); }