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/cvs/cvsroot/libptytty/src/logging.C
Revision: 1.34
Committed: Tue May 17 09:39:26 2011 UTC (15 years, 4 months ago) by sf-exg
Content type: text/plain
Branch: MAIN
Changes since 1.33: +3 -5 lines
Log Message:
Make sure that utmp_pos is initialized when write_bsd_utmp fails.

File Contents

# Content
1 // This file is part of libptytty. Do not make local modifications.
2 // http://software.schmorp.de/pkg/libptytty
3
4 /*----------------------------------------------------------------------*
5 * File: logging.C
6 *----------------------------------------------------------------------*
7 *
8 * All portions of code are copyright by their respective author/s.
9 * Copyright (c) 1992 John Bovey <jdb@ukc.ac.uk>
10 * - original version
11 * Copyright (c) 1993 lipka
12 * Copyright (c) 1993 Brian Stempien <stempien@cs.wmich.edu>
13 * Copyright (c) 1995 Raul Garcia Garcia <rgg@tid.es>
14 * Copyright (c) 1995 Piet W. Plomp <piet@idefix.icce.rug.nl>
15 * Copyright (c) 1997 Raul Garcia Garcia <rgg@tid.es>
16 * Copyright (c) 1998-2001 Geoff Wing <gcw@pobox.com>
17 * - extensive modifications
18 * Copyright (c) 1999 D J Hawkey Jr <hawkeyd@visi.com>
19 * - lastlog support
20 * Copyright (c) 2004-2006 Marc Lehmann <schmorp@schmorp.de>
21 * Copyright (c) 2006 Emanuele Giaquinta <e.giaquinta@glauco.it>
22 *
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
27 *
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
32 *
33 * You should have received a copy of the GNU General Public License
34 * along with this program; if not, write to the Free Software
35 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
36 *----------------------------------------------------------------------*/
37
38 #include "config.h"
39
40 #include "ptytty.h"
41
42 #if UTMP_SUPPORT
43
44 #include <cstdio>
45 #include <cstring>
46
47 #include <sys/types.h>
48 #include <sys/stat.h>
49 #include <fcntl.h>
50 #include <unistd.h>
51 #include <time.h>
52 #include <errno.h>
53
54 /*
55 * BSD style utmp entry
56 * ut_line, ut_name, ut_host, ut_time
57 * SYSV style utmp (and utmpx) entry
58 * ut_user, ut_id, ut_line, ut_pid, ut_type, ut_exit, ut_time
59 */
60
61 /* ------------------------------------------------------------------------- */
62 /*
63 * Write a BSD style utmp entry
64 */
65 #if defined(HAVE_STRUCT_UTMP) && !defined(HAVE_UTMP_PID)
66 static int
67 write_bsd_utmp (int utmp_pos, struct utmp *wu)
68 {
69 int fd;
70
71 if (utmp_pos <= 0 || (fd = open (UTMP_FILE, O_WRONLY)) == -1)
72 return 0;
73
74 if (lseek (fd, (off_t) (utmp_pos * sizeof (struct utmp)), SEEK_SET) != -1)
75 write (fd, wu, sizeof (struct utmp));
76 close (fd);
77 return 1;
78 }
79 #endif
80
81 /* ------------------------------------------------------------------------- */
82 /*
83 * Update a BSD style wtmp entry
84 */
85 #if defined(WTMP_SUPPORT) && !defined(HAVE_UPDWTMP) && defined(HAVE_STRUCT_UTMP)
86 static void
87 update_wtmp (const char *fname, const struct utmp *putmp)
88 {
89 int fd, gotlock, retry;
90 struct flock lck; /* fcntl locking scheme */
91 struct stat sbuf;
92
93 if ((fd = open (fname, O_WRONLY | O_APPEND, 0)) < 0)
94 return;
95
96 lck.l_whence = SEEK_END; /* start lock at current eof */
97 lck.l_len = 0; /* end at ``largest possible eof'' */
98 lck.l_start = 0;
99 lck.l_type = F_WRLCK; /* we want a write lock */
100
101 /* attempt lock with F_SETLK; F_SETLKW would cause a deadlock! */
102 for (retry = 10, gotlock = 0; retry--;)
103 if (fcntl (fd, F_SETLK, &lck) != -1)
104 {
105 gotlock = 1;
106 break;
107 }
108 else if (errno != EAGAIN && errno != EACCES)
109 break;
110 if (!gotlock)
111 {
112 /* give it up */
113 close (fd);
114 return;
115 }
116 if (fstat (fd, &sbuf) == 0)
117 if (write (fd, putmp, sizeof (struct utmp)) != sizeof (struct utmp))
118 ftruncate (fd, sbuf.st_size); /* remove bad writes */
119
120 lck.l_type = F_UNLCK; /* unlocking the file */
121 fcntl (fd, F_SETLK, &lck);
122 close (fd);
123 }
124 #endif
125
126 /* ------------------------------------------------------------------------- */
127 #ifdef LASTLOG_SUPPORT
128 static void
129 update_lastlog (const char *pty, const char *host)
130 {
131 # if defined(HAVE_STRUCT_LASTLOGX) && defined(HAVE_UPDLASTLOGX)
132 struct lastlogx llx;
133 # endif
134 # ifdef HAVE_STRUCT_LASTLOG
135 int fd;
136 struct lastlog ll;
137 char lastlogfile[256];
138 struct passwd *pwent;
139 struct stat st;
140 # endif
141
142 # if defined(HAVE_STRUCT_LASTLOGX) && defined(HAVE_UPDLASTLOGX)
143 memset (&llx, 0, sizeof (llx));
144 llx.ll_tv.tv_sec = time (NULL);
145 llx.ll_tv.tv_usec = 0;
146 strncpy (llx.ll_line, pty, sizeof (llx.ll_line));
147 strncpy (llx.ll_host, host, sizeof (llx.ll_host));
148 updlastlogx (LASTLOGX_FILE, getuid (), &llx);
149 # endif
150
151 # ifdef HAVE_STRUCT_LASTLOG
152 pwent = getpwuid (getuid ());
153 if (!pwent)
154 {
155 ptytty_warn ("no entry in password file, not updating lastlog.\n", 0);
156 return;
157 }
158
159 memset (&ll, 0, sizeof (ll));
160 ll.ll_time = time (NULL);
161 strncpy (ll.ll_line, pty, sizeof (ll.ll_line));
162 strncpy (ll.ll_host, host, sizeof (ll.ll_host));
163 if (stat (LASTLOG_FILE, &st) != 0)
164 return;
165 if (S_ISDIR (st.st_mode))
166 {
167 snprintf (lastlogfile, sizeof (lastlogfile), "%s/%s", LASTLOG_FILE,
168 (!pwent->pw_name || pwent->pw_name[0] == '\0') ? "unknown"
169 : pwent->pw_name);
170 if ((fd = open (lastlogfile, O_WRONLY | O_CREAT, 0644)) >= 0)
171 {
172 write (fd, &ll, sizeof (ll));
173 close (fd);
174 }
175 }
176 else if (S_ISREG (st.st_mode))
177 if ((fd = open (LASTLOG_FILE, O_RDWR)) != -1)
178 {
179 if (lseek (fd, (off_t) ((long)pwent->pw_uid * sizeof (ll)),
180 SEEK_SET) != -1)
181 write (fd, &ll, sizeof (ll));
182 close (fd);
183 }
184 # endif /* HAVE_STRUCT_LASTLOG */
185 }
186 #endif /* LASTLOG_SUPPORT */
187
188 #ifdef HAVE_STRUCT_UTMP
189 static void
190 fill_utmp (struct utmp *ut, bool login, int pid, const char *id, const char *line, const char *user, const char *host)
191 {
192 memset (ut, 0, sizeof (struct utmp));
193
194 # ifdef HAVE_UTMP_PID
195 strncpy (ut->ut_id, id, sizeof (ut->ut_id));
196 ut->ut_pid = pid;
197 # endif
198 ut->ut_time = time (NULL);
199
200 if (login)
201 {
202 strncpy (ut->ut_line, line, sizeof (ut->ut_line));
203 # ifdef HAVE_UTMP_PID
204 strncpy (ut->ut_user, user, sizeof (ut->ut_user));
205 # else
206 strncpy (ut->ut_name, user, sizeof (ut->ut_name));
207 # endif
208 # ifdef HAVE_UTMP_HOST
209 strncpy (ut->ut_host, host, sizeof (ut->ut_host));
210 # endif
211 }
212 }
213 #endif
214
215 #ifdef HAVE_STRUCT_UTMPX
216 static void
217 fill_utmpx (struct utmpx *utx, bool login, int pid, const char *id, const char *line, const char *user, const char *host)
218 {
219 memset (utx, 0, sizeof (struct utmpx));
220
221 strncpy (utx->ut_id, id, sizeof (utx->ut_id));
222 utx->ut_pid = pid;
223 utx->ut_tv.tv_sec = time (NULL);
224 utx->ut_tv.tv_usec = 0;
225 # if HAVE_UTMPX_SESSION
226 utx->ut_session = getsid (0);
227 # endif
228
229 if (login)
230 {
231 strncpy (utx->ut_line, line, sizeof (utx->ut_line));
232 strncpy (utx->ut_user, user, sizeof (utx->ut_user));
233 # ifdef HAVE_UTMPX_HOST
234 strncpy (utx->ut_host, host, sizeof (utx->ut_host));
235 # endif
236 }
237 }
238 #endif
239
240 /* ------------------------------------------------------------------------- */
241
242 /*
243 * make and write utmp and wtmp entries
244 */
245 void
246 ptytty_unix::login (int cmd_pid, bool login_shell, const char *hostname)
247 {
248 const char *pty = name;
249
250 if (!pty || !*pty)
251 return;
252
253 this->cmd_pid = cmd_pid;
254 this->login_shell = login_shell;
255
256 #ifdef HAVE_STRUCT_UTMP
257 struct utmp *ut = &this->ut;
258 #endif
259 #ifdef HAVE_STRUCT_UTMPX
260 struct utmpx *utx = &this->utx;
261 #endif
262 int i;
263 struct passwd *pwent = getpwuid (getuid ());
264 const char *name = (pwent && pwent->pw_name) ? pwent->pw_name : "?";
265
266 if (!strncmp (pty, "/dev/", 5))
267 pty += 5; /* skip /dev/ prefix */
268
269 #if defined(HAVE_UTMP_PID) || defined(HAVE_STRUCT_UTMPX)
270 if (!strncmp (pty, "pty", 3) || !strncmp (pty, "tty", 3))
271 strncpy (ut_id, pty + 3, sizeof (ut_id));
272 else if (sscanf (pty, "pts/%d", &i) == 1)
273 sprintf (ut_id, "vt%02x", (i & 0xff)); /* sysv naming */
274 else
275 {
276 ptytty_warn ("can't parse tty name \"%s\", not adding utmp entry.\n", pty);
277 return;
278 }
279 #endif
280
281 #ifdef HAVE_STRUCT_UTMP
282 fill_utmp (ut, true, cmd_pid, ut_id, pty, name, hostname);
283 # ifdef HAVE_UTMP_PID
284 setutent ();
285 ut->ut_type = DEAD_PROCESS;
286 getutid (ut); /* position to entry in utmp file */
287 # endif
288 #endif
289
290 #ifdef HAVE_STRUCT_UTMPX
291 fill_utmpx (utx, true, cmd_pid, ut_id, pty, name, hostname);
292 setutxent ();
293 utx->ut_type = DEAD_PROCESS;
294 getutxid (utx); /* position to entry in utmp file */
295 #endif
296
297 #ifdef HAVE_STRUCT_UTMP
298 # ifdef HAVE_UTMP_PID
299 ut->ut_type = USER_PROCESS;
300 pututline (ut);
301 endutent (); /* close the file */
302 # endif
303 #endif
304
305 #ifdef HAVE_STRUCT_UTMPX
306 utx->ut_type = USER_PROCESS;
307 pututxline (utx);
308 endutxent (); /* close the file */
309 #endif
310
311 #if defined(HAVE_STRUCT_UTMP) && !defined(HAVE_UTMP_PID)
312 {
313 # if 1
314 int fdstdin = dup (STDIN_FILENO);
315 dup2 (tty, STDIN_FILENO);
316
317 utmp_pos = ttyslot ();
318 if (!write_bsd_utmp (utmp_pos, ut))
319 utmp_pos = 0;
320
321 dup2 (fdstdin, STDIN_FILENO);
322 close (fdstdin);
323 # endif
324 }
325 #endif
326
327 #ifdef WTMP_SUPPORT
328 #ifdef LOG_ONLY_ON_LOGIN
329 if (login_shell)
330 #endif
331 {
332 # ifdef HAVE_STRUCT_UTMP
333 # ifdef HAVE_UPDWTMP
334 updwtmp (WTMP_FILE, ut);
335 # else
336 update_wtmp (WTMP_FILE, ut);
337 # endif
338 # endif
339 # if defined(HAVE_STRUCT_UTMPX) && defined(HAVE_UPDWTMPX)
340 updwtmpx (WTMPX_FILE, utx);
341 # endif
342 }
343 #endif
344 #ifdef LASTLOG_SUPPORT
345 #ifdef LOG_ONLY_ON_LOGIN
346 if (login_shell)
347 #endif
348 update_lastlog (pty, hostname);
349 #endif
350 }
351
352 /* ------------------------------------------------------------------------- */
353 /*
354 * remove utmp and wtmp entries
355 */
356 void
357 ptytty_unix::logout ()
358 {
359 if (!cmd_pid)
360 return;
361
362 #ifdef HAVE_STRUCT_UTMP
363 struct utmp *tmput, *ut = &this->ut;
364 #endif
365 #ifdef HAVE_STRUCT_UTMPX
366 struct utmpx *tmputx, *utx = &this->utx;
367 #endif
368
369 #ifdef HAVE_STRUCT_UTMP
370 fill_utmp (ut, false, cmd_pid, ut_id, 0, 0, 0);
371 # ifdef HAVE_UTMP_PID
372 setutent ();
373 ut->ut_type = USER_PROCESS;
374 tmput = getutid (ut); /* position to entry in utmp file */
375 ut->ut_type = DEAD_PROCESS;
376 # endif
377 #endif
378
379 #ifdef HAVE_STRUCT_UTMPX
380 fill_utmpx (utx, false, cmd_pid, ut_id, 0, 0, 0);
381 setutxent ();
382 utx->ut_type = USER_PROCESS;
383 tmputx = getutxid (utx); /* position to entry in utmp file */
384 utx->ut_type = DEAD_PROCESS;
385 #endif
386
387 /*
388 * Write ending wtmp entry
389 */
390 #ifdef WTMP_SUPPORT
391 #ifdef LOG_ONLY_ON_LOGIN
392 if (login_shell)
393 #endif
394 {
395 # ifdef HAVE_STRUCT_UTMP
396 # ifdef HAVE_UPDWTMP
397 updwtmp (WTMP_FILE, ut);
398 # else
399 update_wtmp (WTMP_FILE, ut);
400 # endif
401 # endif
402 # if defined(HAVE_STRUCT_UTMPX) && defined(HAVE_UPDWTMPX)
403 updwtmpx (WTMPX_FILE, utx);
404 # endif
405 }
406 #endif
407
408 /*
409 * Write utmp entry
410 */
411 #ifdef HAVE_STRUCT_UTMP
412 # ifdef HAVE_UTMP_PID
413 if (tmput && tmput->ut_pid == cmd_pid)
414 pututline (ut);
415 endutent ();
416 # else
417 write_bsd_utmp (utmp_pos, ut);
418 # endif
419 #endif
420 #ifdef HAVE_STRUCT_UTMPX
421 if (tmputx && tmputx->ut_pid == cmd_pid)
422 pututxline (utx);
423 endutxent ();
424 #endif
425
426 cmd_pid = 0;
427 }
428
429 #else
430 void
431 ptytty_unix::login (int cmd_pid, bool login_shell, const char *hostname)
432 {
433 }
434 #endif
435