source: trunk/server/source3/lib/username.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 6.8 KB
RevLine 
[745]1/*
2 Unix SMB/CIFS implementation.
3 Username handling
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Jeremy Allison 1997-2001.
6 Copyright (C) Andrew Bartlett 2002
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20*/
21
22#include "includes.h"
23#include "system/passwd.h"
24#include "memcache.h"
25#include "../lib/util/util_pw.h"
26
27/* internal functions */
28static struct passwd *uname_string_combinations(char *s, TALLOC_CTX *mem_ctx,
29 struct passwd * (*fn) (TALLOC_CTX *mem_ctx, const char *),
30 int N);
31static struct passwd *uname_string_combinations2(char *s, TALLOC_CTX *mem_ctx, int offset,
32 struct passwd * (*fn) (TALLOC_CTX *mem_ctx, const char *),
33 int N);
34
35static struct passwd *getpwnam_alloc_cached(TALLOC_CTX *mem_ctx, const char *name)
36{
37 struct passwd *pw, *for_cache;
38
39 pw = (struct passwd *)memcache_lookup_talloc(
40 NULL, GETPWNAM_CACHE, data_blob_string_const_null(name));
41 if (pw != NULL) {
42 return tcopy_passwd(mem_ctx, pw);
43 }
44
45 pw = sys_getpwnam(name);
46 if (pw == NULL) {
47 return NULL;
48 }
49
50 for_cache = tcopy_passwd(talloc_tos(), pw);
51 if (for_cache == NULL) {
52 return NULL;
53 }
54
55 memcache_add_talloc(NULL, GETPWNAM_CACHE,
56 data_blob_string_const_null(name), &for_cache);
57
58 return tcopy_passwd(mem_ctx, pw);
59}
60
61/****************************************************************************
62 Flush all cached passwd structs.
63****************************************************************************/
64
65void flush_pwnam_cache(void)
66{
67 memcache_flush(NULL, GETPWNAM_CACHE);
68}
69
70/****************************************************************************
71 Get a users home directory.
72****************************************************************************/
73
74char *get_user_home_dir(TALLOC_CTX *mem_ctx, const char *user)
75{
76 struct passwd *pass;
77 char *result;
78
79 /* Ensure the user exists. */
80
81 pass = Get_Pwnam_alloc(mem_ctx, user);
82
83 if (!pass)
84 return(NULL);
85
86 /* Return home directory from struct passwd. */
87
88 result = talloc_move(mem_ctx, &pass->pw_dir);
89
90 TALLOC_FREE(pass);
91 return result;
92}
93
94/****************************************************************************
95 * A wrapper for sys_getpwnam(). The following variations are tried:
96 * - as transmitted
97 * - in all lower case if this differs from transmitted
98 * - in all upper case if this differs from transmitted
99 * - using lp_usernamelevel() for permutations.
100****************************************************************************/
101
102static struct passwd *Get_Pwnam_internals(TALLOC_CTX *mem_ctx,
103 const char *user, char *user2)
104{
105 struct passwd *ret = NULL;
106
107 if (!user2 || !(*user2))
108 return(NULL);
109
110 if (!user || !(*user))
111 return(NULL);
112
113 /* Try in all lower case first as this is the most
114 common case on UNIX systems */
115 strlower_m(user2);
116 DEBUG(5,("Trying _Get_Pwnam(), username as lowercase is %s\n",user2));
117 ret = getpwnam_alloc_cached(mem_ctx, user2);
118 if(ret)
119 goto done;
120
121 /* Try as given, if username wasn't originally lowercase */
122 if(strcmp(user, user2) != 0) {
123 DEBUG(5,("Trying _Get_Pwnam(), username as given is %s\n",
124 user));
125 ret = getpwnam_alloc_cached(mem_ctx, user);
126 if(ret)
127 goto done;
128 }
129
130 /* Try as uppercase, if username wasn't originally uppercase */
131 strupper_m(user2);
132 if(strcmp(user, user2) != 0) {
133 DEBUG(5,("Trying _Get_Pwnam(), username as uppercase is %s\n",
134 user2));
135 ret = getpwnam_alloc_cached(mem_ctx, user2);
136 if(ret)
137 goto done;
138 }
139
140 /* Try all combinations up to usernamelevel */
141 strlower_m(user2);
142 DEBUG(5,("Checking combinations of %d uppercase letters in %s\n",
143 lp_usernamelevel(), user2));
144 ret = uname_string_combinations(user2, mem_ctx, getpwnam_alloc_cached,
145 lp_usernamelevel());
146
147done:
148 DEBUG(5,("Get_Pwnam_internals %s find user [%s]!\n",ret ?
149 "did":"didn't", user));
150
151 return ret;
152}
153
154/****************************************************************************
155 Get_Pwnam wrapper without modification.
156 NOTE: This with NOT modify 'user'!
157 This will return an allocated structure
158****************************************************************************/
159
160struct passwd *Get_Pwnam_alloc(TALLOC_CTX *mem_ctx, const char *user)
161{
162 fstring user2;
163
164 if ( *user == '\0' ) {
165 DEBUG(10,("Get_Pwnam: empty username!\n"));
166 return NULL;
167 }
168
169 fstrcpy(user2, user);
170
171 DEBUG(5,("Finding user %s\n", user));
172
173 return Get_Pwnam_internals(mem_ctx, user, user2);
174}
175
176/* The functions below have been taken from password.c and slightly modified */
177/****************************************************************************
178 Apply a function to upper/lower case combinations
179 of a string and return true if one of them returns true.
180 Try all combinations with N uppercase letters.
181 offset is the first char to try and change (start with 0)
182 it assumes the string starts lowercased
183****************************************************************************/
184
185static struct passwd *uname_string_combinations2(char *s, TALLOC_CTX *mem_ctx,
186 int offset,
187 struct passwd *(*fn)(TALLOC_CTX *mem_ctx, const char *),
188 int N)
189{
190 ssize_t len = (ssize_t)strlen(s);
191 int i;
192 struct passwd *ret;
193
194 if (N <= 0 || offset >= len)
195 return(fn(mem_ctx, s));
196
197 for (i=offset;i<(len-(N-1));i++) {
198 char c = s[i];
199 if (!islower_m((int)c))
200 continue;
201 s[i] = toupper_m(c);
202 ret = uname_string_combinations2(s, mem_ctx, i+1, fn, N-1);
203 if(ret)
204 return(ret);
205 s[i] = c;
206 }
207 return(NULL);
208}
209
210/****************************************************************************
211 Apply a function to upper/lower case combinations
212 of a string and return true if one of them returns true.
213 Try all combinations with up to N uppercase letters.
214 offset is the first char to try and change (start with 0)
215 it assumes the string starts lowercased
216****************************************************************************/
217
218static struct passwd * uname_string_combinations(char *s, TALLOC_CTX *mem_ctx,
219 struct passwd * (*fn)(TALLOC_CTX *mem_ctx, const char *),
220 int N)
221{
222 int n;
223 struct passwd *ret;
224
225 for (n=1;n<=N;n++) {
226 ret = uname_string_combinations2(s,mem_ctx,0,fn,n);
227 if(ret)
228 return(ret);
229 }
230 return(NULL);
231}
232
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