source: vendor/current/source3/lib/username.c

Last change on this file was 988, checked in by Silvan Scherrer, 9 years ago

Samba Server: update vendor to version 4.4.3
File size: 6.8 KB
Line 
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 "../lib/util/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 = 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 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_username_level() 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 if (!strlower_m(user2)) {
116 DEBUG(5,("strlower_m %s failed\n", user2));
117 goto done;
118 }
119
120 DEBUG(5,("Trying _Get_Pwnam(), username as lowercase is %s\n",user2));
121 ret = getpwnam_alloc_cached(mem_ctx, user2);
122 if(ret)
123 goto done;
124
125 /* Try as given, if username wasn't originally lowercase */
126 if(strcmp(user, user2) != 0) {
127 DEBUG(5,("Trying _Get_Pwnam(), username as given is %s\n",
128 user));
129 ret = getpwnam_alloc_cached(mem_ctx, user);
130 if(ret)
131 goto done;
132 }
133
134 /* Try as uppercase, if username wasn't originally uppercase */
135 if (!strupper_m(user2)) {
136 goto done;
137 }
138
139 if(strcmp(user, user2) != 0) {
140 DEBUG(5,("Trying _Get_Pwnam(), username as uppercase is %s\n",
141 user2));
142 ret = getpwnam_alloc_cached(mem_ctx, user2);
143 if(ret)
144 goto done;
145 }
146
147 /* Try all combinations up to usernamelevel */
148 if (!strlower_m(user2)) {
149 DEBUG(5,("strlower_m %s failed\n", user2));
150 goto done;
151 }
152 DEBUG(5,("Checking combinations of %d uppercase letters in %s\n",
153 lp_username_level(), user2));
154 ret = uname_string_combinations(user2, mem_ctx, getpwnam_alloc_cached,
155 lp_username_level());
156
157done:
158 DEBUG(5,("Get_Pwnam_internals %s find user [%s]!\n",ret ?
159 "did":"didn't", user));
160
161 return ret;
162}
163
164/****************************************************************************
165 Get_Pwnam wrapper without modification.
166 NOTE: This with NOT modify 'user'!
167 This will return an allocated structure
168****************************************************************************/
169
170struct passwd *Get_Pwnam_alloc(TALLOC_CTX *mem_ctx, const char *user)
171{
172 fstring user2;
173
174 if ( *user == '\0' ) {
175 DEBUG(10,("Get_Pwnam: empty username!\n"));
176 return NULL;
177 }
178
179 fstrcpy(user2, user);
180
181 DEBUG(5,("Finding user %s\n", user));
182
183 return Get_Pwnam_internals(mem_ctx, user, user2);
184}
185
186/* The functions below have been taken from password.c and slightly modified */
187/****************************************************************************
188 Apply a function to upper/lower case combinations
189 of a string and return true if one of them returns true.
190 Try all combinations with N uppercase letters.
191 offset is the first char to try and change (start with 0)
192 it assumes the string starts lowercased
193****************************************************************************/
194
195static struct passwd *uname_string_combinations2(char *s, TALLOC_CTX *mem_ctx,
196 int offset,
197 struct passwd *(*fn)(TALLOC_CTX *mem_ctx, const char *),
198 int N)
199{
200 ssize_t len = (ssize_t)strlen(s);
201 int i;
202 struct passwd *ret;
203
204 if (N <= 0 || offset >= len)
205 return(fn(mem_ctx, s));
206
207 for (i=offset;i<(len-(N-1));i++) {
208 char c = s[i];
209 if (!islower_m((int)c))
210 continue;
211 s[i] = toupper_m(c);
212 ret = uname_string_combinations2(s, mem_ctx, i+1, fn, N-1);
213 if(ret)
214 return(ret);
215 s[i] = c;
216 }
217 return(NULL);
218}
219
220/****************************************************************************
221 Apply a function to upper/lower case combinations
222 of a string and return true if one of them returns true.
223 Try all combinations with up to N uppercase letters.
224 offset is the first char to try and change (start with 0)
225 it assumes the string starts lowercased
226****************************************************************************/
227
228static struct passwd * uname_string_combinations(char *s, TALLOC_CTX *mem_ctx,
229 struct passwd * (*fn)(TALLOC_CTX *mem_ctx, const char *),
230 int N)
231{
232 int n;
233 struct passwd *ret;
234
235 for (n=1;n<=N;n++) {
236 ret = uname_string_combinations2(s,mem_ctx,0,fn,n);
237 if(ret)
238 return(ret);
239 }
240 return(NULL);
241}
242
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