1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2010 Ed Schouten <[email protected]>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include "namespace.h"
33 #include <sys/endian.h>
34 #include <sys/param.h>
35 #include <sys/stat.h>
36 #include <errno.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <utmpx.h>
40 #include "utxdb.h"
41 #include "un-namespace.h"
42
43 static _Thread_local FILE *uf = NULL;
44 static _Thread_local int udb;
45
46 int
setutxdb(int db,const char * file)47 setutxdb(int db, const char *file)
48 {
49 struct stat sb;
50
51 switch (db) {
52 case UTXDB_ACTIVE:
53 if (file == NULL)
54 file = _PATH_UTX_ACTIVE;
55 break;
56 case UTXDB_LASTLOGIN:
57 if (file == NULL)
58 file = _PATH_UTX_LASTLOGIN;
59 break;
60 case UTXDB_LOG:
61 if (file == NULL)
62 file = _PATH_UTX_LOG;
63 break;
64 default:
65 errno = EINVAL;
66 return (-1);
67 }
68
69 if (uf != NULL)
70 fclose(uf);
71 uf = fopen(file, "re");
72 if (uf == NULL)
73 return (-1);
74
75 if (db != UTXDB_LOG) {
76 /* Safety check: never use broken files. */
77 if (_fstat(fileno(uf), &sb) != -1 &&
78 sb.st_size % sizeof(struct futx) != 0) {
79 fclose(uf);
80 uf = NULL;
81 errno = EFTYPE;
82 return (-1);
83 }
84 /* Prevent reading of partial records. */
85 (void)setvbuf(uf, NULL, _IOFBF,
86 rounddown(BUFSIZ, sizeof(struct futx)));
87 }
88
89 udb = db;
90 return (0);
91 }
92
93 void
setutxent(void)94 setutxent(void)
95 {
96
97 setutxdb(UTXDB_ACTIVE, NULL);
98 }
99
100 void
endutxent(void)101 endutxent(void)
102 {
103
104 if (uf != NULL) {
105 fclose(uf);
106 uf = NULL;
107 }
108 }
109
110 static int
getfutxent(struct futx * fu)111 getfutxent(struct futx *fu)
112 {
113
114 if (uf == NULL)
115 setutxent();
116 if (uf == NULL)
117 return (-1);
118
119 if (udb == UTXDB_LOG) {
120 uint16_t len;
121
122 retry:
123 if (fread(&len, sizeof(len), 1, uf) != 1)
124 return (-1);
125 len = be16toh(len);
126 if (len == 0) {
127 /*
128 * XXX: Though zero-size records are valid in theory,
129 * they can never occur in practice. Zero-size records
130 * indicate file corruption. Seek one byte forward, to
131 * see if we can find a record there.
132 */
133 ungetc('\0', uf);
134 goto retry;
135 }
136 if (len > sizeof *fu) {
137 /* Forward compatibility. */
138 if (fread(fu, sizeof(*fu), 1, uf) != 1)
139 return (-1);
140 fseek(uf, len - sizeof(*fu), SEEK_CUR);
141 } else {
142 /* Partial record. */
143 memset(fu, 0, sizeof(*fu));
144 if (fread(fu, len, 1, uf) != 1)
145 return (-1);
146 }
147 } else {
148 if (fread(fu, sizeof(*fu), 1, uf) != 1)
149 return (-1);
150 }
151 return (0);
152 }
153
154 struct utmpx *
getutxent(void)155 getutxent(void)
156 {
157 struct futx fu;
158
159 if (getfutxent(&fu) != 0)
160 return (NULL);
161 return (futx_to_utx(&fu));
162 }
163
164 struct utmpx *
getutxid(const struct utmpx * id)165 getutxid(const struct utmpx *id)
166 {
167 struct futx fu;
168
169 for (;;) {
170 if (getfutxent(&fu) != 0)
171 return (NULL);
172
173 switch (fu.fu_type) {
174 case USER_PROCESS:
175 case INIT_PROCESS:
176 case LOGIN_PROCESS:
177 case DEAD_PROCESS:
178 switch (id->ut_type) {
179 case USER_PROCESS:
180 case INIT_PROCESS:
181 case LOGIN_PROCESS:
182 case DEAD_PROCESS:
183 if (memcmp(fu.fu_id, id->ut_id,
184 MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) ==
185 0)
186 goto found;
187 }
188 break;
189 default:
190 if (fu.fu_type == id->ut_type)
191 goto found;
192 break;
193 }
194 }
195
196 found:
197 return (futx_to_utx(&fu));
198 }
199
200 struct utmpx *
getutxline(const struct utmpx * line)201 getutxline(const struct utmpx *line)
202 {
203 struct futx fu;
204
205 for (;;) {
206 if (getfutxent(&fu) != 0)
207 return (NULL);
208
209 switch (fu.fu_type) {
210 case USER_PROCESS:
211 case LOGIN_PROCESS:
212 if (strncmp(fu.fu_line, line->ut_line,
213 MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) ==
214 0)
215 goto found;
216 break;
217 }
218 }
219
220 found:
221 return (futx_to_utx(&fu));
222 }
223
224 struct utmpx *
getutxuser(const char * user)225 getutxuser(const char *user)
226 {
227 struct futx fu;
228
229 for (;;) {
230 if (getfutxent(&fu) != 0)
231 return (NULL);
232
233 switch (fu.fu_type) {
234 case USER_PROCESS:
235 if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0)
236 goto found;
237 break;
238 }
239 }
240
241 found:
242 return (futx_to_utx(&fu));
243 }
244