1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2010 Ed Schouten <ed@FreeBSD.org>
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 "namespace.h"
30 #include <sys/endian.h>
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <errno.h>
34 #include <stdio.h>
35 #include <string.h>
36 #include <utmpx.h>
37 #include "utxdb.h"
38 #include "un-namespace.h"
39
40 static _Thread_local FILE *uf = NULL;
41 static _Thread_local int udb;
42
43 int
setutxdb(int db,const char * file)44 setutxdb(int db, const char *file)
45 {
46 struct stat sb;
47
48 switch (db) {
49 case UTXDB_ACTIVE:
50 if (file == NULL)
51 file = _PATH_UTX_ACTIVE;
52 break;
53 case UTXDB_LASTLOGIN:
54 if (file == NULL)
55 file = _PATH_UTX_LASTLOGIN;
56 break;
57 case UTXDB_LOG:
58 if (file == NULL)
59 file = _PATH_UTX_LOG;
60 break;
61 default:
62 errno = EINVAL;
63 return (-1);
64 }
65
66 if (uf != NULL)
67 fclose(uf);
68 uf = fopen(file, "re");
69 if (uf == NULL)
70 return (-1);
71
72 if (db != UTXDB_LOG) {
73 /* Safety check: never use broken files. */
74 if (_fstat(fileno(uf), &sb) != -1 &&
75 sb.st_size % sizeof(struct futx) != 0) {
76 fclose(uf);
77 uf = NULL;
78 errno = EFTYPE;
79 return (-1);
80 }
81 /* Prevent reading of partial records. */
82 (void)setvbuf(uf, NULL, _IOFBF,
83 rounddown(BUFSIZ, sizeof(struct futx)));
84 }
85
86 udb = db;
87 return (0);
88 }
89
90 void
setutxent(void)91 setutxent(void)
92 {
93
94 setutxdb(UTXDB_ACTIVE, NULL);
95 }
96
97 void
endutxent(void)98 endutxent(void)
99 {
100
101 if (uf != NULL) {
102 fclose(uf);
103 uf = NULL;
104 }
105 }
106
107 static int
getfutxent(struct futx * fu)108 getfutxent(struct futx *fu)
109 {
110
111 if (uf == NULL)
112 setutxent();
113 if (uf == NULL)
114 return (-1);
115
116 if (udb == UTXDB_LOG) {
117 uint16_t len;
118
119 retry:
120 if (fread(&len, sizeof(len), 1, uf) != 1)
121 return (-1);
122 len = be16toh(len);
123 if (len == 0) {
124 /*
125 * XXX: Though zero-size records are valid in theory,
126 * they can never occur in practice. Zero-size records
127 * indicate file corruption. Seek one byte forward, to
128 * see if we can find a record there.
129 */
130 ungetc('\0', uf);
131 goto retry;
132 }
133 if (len > sizeof *fu) {
134 /* Forward compatibility. */
135 if (fread(fu, sizeof(*fu), 1, uf) != 1)
136 return (-1);
137 fseek(uf, len - sizeof(*fu), SEEK_CUR);
138 } else {
139 /* Partial record. */
140 memset(fu, 0, sizeof(*fu));
141 if (fread(fu, len, 1, uf) != 1)
142 return (-1);
143 }
144 } else {
145 if (fread(fu, sizeof(*fu), 1, uf) != 1)
146 return (-1);
147 }
148 return (0);
149 }
150
151 struct utmpx *
getutxent(void)152 getutxent(void)
153 {
154 struct futx fu;
155
156 if (getfutxent(&fu) != 0)
157 return (NULL);
158 return (futx_to_utx(&fu));
159 }
160
161 struct utmpx *
getutxid(const struct utmpx * id)162 getutxid(const struct utmpx *id)
163 {
164 struct futx fu;
165
166 for (;;) {
167 if (getfutxent(&fu) != 0)
168 return (NULL);
169
170 switch (fu.fu_type) {
171 case USER_PROCESS:
172 case INIT_PROCESS:
173 case LOGIN_PROCESS:
174 case DEAD_PROCESS:
175 switch (id->ut_type) {
176 case USER_PROCESS:
177 case INIT_PROCESS:
178 case LOGIN_PROCESS:
179 case DEAD_PROCESS:
180 if (memcmp(fu.fu_id, id->ut_id,
181 MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) ==
182 0)
183 goto found;
184 }
185 break;
186 default:
187 if (fu.fu_type == id->ut_type)
188 goto found;
189 break;
190 }
191 }
192
193 found:
194 return (futx_to_utx(&fu));
195 }
196
197 struct utmpx *
getutxline(const struct utmpx * line)198 getutxline(const struct utmpx *line)
199 {
200 struct futx fu;
201
202 for (;;) {
203 if (getfutxent(&fu) != 0)
204 return (NULL);
205
206 switch (fu.fu_type) {
207 case USER_PROCESS:
208 case LOGIN_PROCESS:
209 if (strncmp(fu.fu_line, line->ut_line,
210 MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) ==
211 0)
212 goto found;
213 break;
214 }
215 }
216
217 found:
218 return (futx_to_utx(&fu));
219 }
220
221 struct utmpx *
getutxuser(const char * user)222 getutxuser(const char *user)
223 {
224 struct futx fu;
225
226 for (;;) {
227 if (getfutxent(&fu) != 0)
228 return (NULL);
229
230 switch (fu.fu_type) {
231 case USER_PROCESS:
232 if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0)
233 goto found;
234 break;
235 }
236 }
237
238 found:
239 return (futx_to_utx(&fu));
240 }
241