source: trunk/server/source3/smbd/utmp.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: 18.0 KB
RevLine 
[745]1/*
2 Unix SMB/CIFS implementation.
3 utmp routines
4 Copyright (C) T.D.Lee@durham.ac.uk 1999
5 Heavily modified by Andrew Bartlett and Tridge, April 2001
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "includes.h"
22#include "system/filesys.h"
23#include "smbd/smbd.h"
24
25/****************************************************************************
26Reflect connection status in utmp/wtmp files.
27 T.D.Lee@durham.ac.uk September 1999
28
29 With grateful thanks since then to many who have helped port it to
30 different operating systems. The variety of OS quirks thereby
31 uncovered is amazing...
32
33Hints for porting:
34 o Always attempt to use programmatic interface (pututline() etc.)
35 Indeed, at present only programmatic use is supported.
36 o The only currently supported programmatic interface to "wtmp{,x}"
37 is through "updwtmp*()" routines.
38 o The "x" (utmpx/wtmpx; HAVE_UTMPX_H) seems preferable.
39 o The HAVE_* items should identify supported features.
40 o If at all possible, avoid "if defined(MY-OS)" constructions.
41
42OS observations and status:
43 Almost every OS seems to have its own quirks.
44
45 Solaris 2.x:
46 Tested on 2.6 and 2.7; should be OK on other flavours.
47 AIX:
48 Apparently has utmpx.h but doesn't implement.
49 OSF:
50 Has utmpx.h, but (e.g.) no "getutmpx()". (Is this like AIX ?)
51 Redhat 6:
52 utmpx.h seems not to set default filenames. non-x better.
53 IRIX 6.5:
54 Not tested. Appears to have "x".
55 HP-UX 9.x:
56 Not tested. Appears to lack "x".
57 HP-UX 10.x:
58 Not tested.
59 "updwtmp*()" routines seem absent, so no current wtmp* support.
60 Has "ut_addr": probably trivial to implement (although remember
61 that IPv6 is coming...).
62
63 FreeBSD:
64 No "putut*()" type of interface.
65 No "ut_type" and associated defines.
66 Write files directly. Alternatively use its login(3)/logout(3).
67 SunOS 4:
68 Not tested. Resembles FreeBSD, but no login()/logout().
69
70lastlog:
71 Should "lastlog" files, if any, be updated?
72 BSD systems (SunOS 4, FreeBSD):
73 o Prominent mention on man pages.
74 System-V (e.g. Solaris 2):
75 o No mention on man pages, even under "man -k".
76 o Has a "/var/adm/lastlog" file, but pututxline() etc. seem
77 not to touch it.
78 o Despite downplaying (above), nevertheless has <lastlog.h>.
79 So perhaps UN*X "lastlog" facility is intended for tty/terminal only?
80
81Notes:
82 Each connection requires a small number (starting at 0, working up)
83 to represent the line. This must be unique within and across all
84 smbd processes. It is the 'id_num' from Samba's session.c code.
85
86 The 4 byte 'ut_id' component is vital to distinguish connections,
87 of which there could be several hundred or even thousand.
88 Entries seem to be printable characters, with optional NULL pads.
89
90 We need to be distinct from other entries in utmp/wtmp.
91
92 Observed things: therefore avoid them. Add to this list please.
93 From Solaris 2.x (because that's what I have):
94 'sN' : run-levels; N: [0-9]
95 'co' : console
96 'CC' : arbitrary things; C: [a-z]
97 'rXNN' : rlogin; N: [0-9]; X: [0-9a-z]
98 'tXNN' : rlogin; N: [0-9]; X: [0-9a-z]
99 '/NNN' : Solaris CDE
100 'ftpZ' : ftp (Z is the number 255, aka 0377, aka 0xff)
101 Mostly a record uses the same 'ut_id' in both "utmp" and "wtmp",
102 but differences have been seen.
103
104 Arbitrarily I have chosen to use a distinctive 'SM' for the
105 first two bytes.
106
107 The remaining two bytes encode the session 'id_num' (see above).
108 Our caller (session.c) should note our 16-bit limitation.
109
110****************************************************************************/
111
112#ifndef WITH_UTMP
113/*
114 * Not WITH_UTMP? Simply supply dummy routines.
115 */
116
117void sys_utmp_claim(const char *username, const char *hostname,
118 const char *ip_addr_str,
119 const char *id_str, int id_num)
120{}
121
122void sys_utmp_yield(const char *username, const char *hostname,
123 const char *ip_addr_str,
124 const char *id_str, int id_num)
125{}
126
127#else /* WITH_UTMP */
128
129#include <utmp.h>
130
131#ifdef HAVE_UTMPX_H
132#include <utmpx.h>
133#endif
134
135/* BSD systems: some may need lastlog.h (SunOS 4), some may not (FreeBSD) */
136/* Some System-V systems (e.g. Solaris 2) declare this too. */
137#ifdef HAVE_LASTLOG_H
138#include <lastlog.h>
139#endif
140
141/****************************************************************************
142 Default paths to various {u,w}tmp{,x} files.
143****************************************************************************/
144
145#ifdef HAVE_UTMPX_H
146
147static const char * const ux_pathname =
148# if defined (UTMPX_FILE)
149 UTMPX_FILE ;
150# elif defined (_UTMPX_FILE)
151 _UTMPX_FILE ;
152# elif defined (_PATH_UTMPX)
153 _PATH_UTMPX ;
154# else
155 "" ;
156# endif
157
158static const char * const wx_pathname =
159# if defined (WTMPX_FILE)
160 WTMPX_FILE ;
161# elif defined (_WTMPX_FILE)
162 _WTMPX_FILE ;
163# elif defined (_PATH_WTMPX)
164 _PATH_WTMPX ;
165# else
166 "" ;
167# endif
168
169#endif /* HAVE_UTMPX_H */
170
171static const char * const ut_pathname =
172# if defined (UTMP_FILE)
173 UTMP_FILE ;
174# elif defined (_UTMP_FILE)
175 _UTMP_FILE ;
176# elif defined (_PATH_UTMP)
177 _PATH_UTMP ;
178# else
179 "" ;
180# endif
181
182static const char * const wt_pathname =
183# if defined (WTMP_FILE)
184 WTMP_FILE ;
185# elif defined (_WTMP_FILE)
186 _WTMP_FILE ;
187# elif defined (_PATH_WTMP)
188 _PATH_WTMP ;
189# else
190 "" ;
191# endif
192
193/* BSD-like systems might want "lastlog" support. */
194#if 0 /* *** Not yet implemented */
195#ifndef HAVE_PUTUTLINE /* see "pututline_my()" */
196static const char *ll_pathname =
197# if defined (_PATH_LASTLOG) /* what other names (if any?) */
198 _PATH_LASTLOG ;
199# else
200 "" ;
201# endif /* _PATH_LASTLOG */
202#endif /* HAVE_PUTUTLINE */
203#endif
204
205/*
206 * Get name of {u,w}tmp{,x} file.
207 * return: fname contains filename
208 * Possibly empty if this code not yet ported to this system.
209 *
210 * utmp{,x}: try "utmp dir", then default (a define)
211 * wtmp{,x}: try "wtmp dir", then "utmp dir", then default (a define)
212 */
213static char *uw_pathname(TALLOC_CTX *ctx,
214 const char *uw_name,
215 const char *uw_default)
216{
217 char *dirname = NULL;
218
219 /* For w-files, first look for explicit "wtmp dir" */
220 if (uw_name[0] == 'w') {
221 dirname = talloc_strdup(ctx, lp_wtmpdir());
222 if (!dirname) {
223 return NULL;
224 }
225 trim_char(dirname,'\0','/');
226 }
227
228 /* For u-files and non-explicit w-dir, look for "utmp dir" */
229 if ((dirname == NULL) || (strlen(dirname) == 0)) {
230 dirname = talloc_strdup(ctx, lp_utmpdir());
231 if (!dirname) {
232 return NULL;
233 }
234 trim_char(dirname,'\0','/');
235 }
236
237 /* If explicit directory above, use it */
238 if (dirname && strlen(dirname) != 0) {
239 return talloc_asprintf(ctx,
240 "%s/%s",
241 dirname,
242 uw_name);
243 }
244
245 /* No explicit directory: attempt to use default paths */
246 if (strlen(uw_default) == 0) {
247 /* No explicit setting, no known default.
248 * Has it yet been ported to this OS?
249 */
250 DEBUG(2,("uw_pathname: unable to determine pathname\n"));
251 }
252 return talloc_strdup(ctx, uw_default);
253}
254
255#ifndef HAVE_PUTUTLINE
256/****************************************************************************
257 Update utmp file directly. No subroutine interface: probably a BSD system.
258****************************************************************************/
259
260static void pututline_my(const char *uname, struct utmp *u, bool claim)
261{
262 DEBUG(1,("pututline_my: not yet implemented\n"));
263 /* BSD implementor: may want to consider (or not) adjusting "lastlog" */
264}
265#endif /* HAVE_PUTUTLINE */
266
267#ifndef HAVE_UPDWTMP
268
269/****************************************************************************
270 Update wtmp file directly. No subroutine interface: probably a BSD system.
271 Credit: Michail Vidiassov <master@iaas.msu.ru>
272****************************************************************************/
273
274static void updwtmp_my(const char *wname, struct utmp *u, bool claim)
275{
276 int fd;
277 struct stat buf;
278
279 if (! claim) {
280 /*
281 * BSD-like systems:
282 * may use empty ut_name to distinguish a logout record.
283 *
284 * May need "if defined(SUNOS4)" etc. around some of these,
285 * but try to avoid if possible.
286 *
287 * SunOS 4:
288 * man page indicates ut_name and ut_host both NULL
289 * FreeBSD 4.0:
290 * man page appears not to specify (hints non-NULL)
291 * A correspondent suggest at least ut_name should be NULL
292 */
293#if defined(HAVE_UT_UT_NAME)
294 memset((char *)&u->ut_name, '\0', sizeof(u->ut_name));
295#endif
296#if defined(HAVE_UT_UT_HOST)
297 memset((char *)&u->ut_host, '\0', sizeof(u->ut_host));
298#endif
299 }
300 /* Stolen from logwtmp function in libutil.
301 * May be more locking/blocking is needed?
302 */
303 if ((fd = open(wname, O_WRONLY|O_APPEND, 0)) < 0)
304 return;
305 if (fstat(fd, &buf) == 0) {
306 if (write(fd, (char *)u, sizeof(struct utmp)) != sizeof(struct utmp))
307 (void) ftruncate(fd, buf.st_size);
308 }
309 (void) close(fd);
310}
311#endif /* HAVE_UPDWTMP */
312
313/****************************************************************************
314 Update via utmp/wtmp (not utmpx/wtmpx).
315****************************************************************************/
316
317static void utmp_nox_update(struct utmp *u, bool claim)
318{
319 char *uname = NULL;
320 char *wname = NULL;
321#if defined(PUTUTLINE_RETURNS_UTMP)
322 struct utmp *urc;
323#endif /* PUTUTLINE_RETURNS_UTMP */
324
325 uname = uw_pathname(talloc_tos(), "utmp", ut_pathname);
326 if (!uname) {
327 return;
328 }
329 DEBUG(2,("utmp_nox_update: uname:%s\n", uname));
330
331#ifdef HAVE_PUTUTLINE
332 if (strlen(uname) != 0) {
333 utmpname(uname);
334 }
335
336# if defined(PUTUTLINE_RETURNS_UTMP)
337 setutent();
338 urc = pututline(u);
339 endutent();
340 if (urc == NULL) {
341 DEBUG(2,("utmp_nox_update: pututline() failed\n"));
342 return;
343 }
344# else /* PUTUTLINE_RETURNS_UTMP */
345 setutent();
346 pututline(u);
347 endutent();
348# endif /* PUTUTLINE_RETURNS_UTMP */
349
350#else /* HAVE_PUTUTLINE */
351 if (strlen(uname) != 0) {
352 pututline_my(uname, u, claim);
353 }
354#endif /* HAVE_PUTUTLINE */
355
356 wname = uw_pathname(talloc_tos(), "wtmp", wt_pathname);
357 if (!wname) {
358 return;
359 }
360 DEBUG(2,("utmp_nox_update: wname:%s\n", wname));
361 if (strlen(wname) != 0) {
362#ifdef HAVE_UPDWTMP
363 updwtmp(wname, u);
364 /*
365 * updwtmp() and the newer updwtmpx() may be unsymmetrical.
366 * At least one OS, Solaris 2.x declares the former in the
367 * "utmpx" (latter) file and context.
368 * In the Solaris case this is irrelevant: it has both and
369 * we always prefer the "x" case, so doesn't come here.
370 * But are there other systems, with no "x", which lack
371 * updwtmp() perhaps?
372 */
373#else
374 updwtmp_my(wname, u, claim);
375#endif /* HAVE_UPDWTMP */
376 }
377}
378
379/****************************************************************************
380 Copy a string in the utmp structure.
381****************************************************************************/
382
383static void utmp_strcpy(char *dest, const char *src, size_t n)
384{
385 size_t len = 0;
386
387 memset(dest, '\0', n);
388 if (src)
389 len = strlen(src);
390 if (len >= n) {
391 memcpy(dest, src, n);
392 } else {
393 if (len)
394 memcpy(dest, src, len);
395 }
396}
397
398/****************************************************************************
399 Update via utmpx/wtmpx (preferred) or via utmp/wtmp.
400****************************************************************************/
401
402static void sys_utmp_update(struct utmp *u, const char *hostname, bool claim)
403{
404#if !defined(HAVE_UTMPX_H)
405 /* No utmpx stuff. Drop to non-x stuff */
406 utmp_nox_update(u, claim);
407#elif !defined(HAVE_PUTUTXLINE)
408 /* Odd. Have utmpx.h but no "pututxline()". Drop to non-x stuff */
409 DEBUG(1,("utmp_update: have utmpx.h but no pututxline() function\n"));
410 utmp_nox_update(u, claim);
411#elif !defined(HAVE_GETUTMPX)
412 /* Odd. Have utmpx.h but no "getutmpx()". Drop to non-x stuff */
413 DEBUG(1,("utmp_update: have utmpx.h but no getutmpx() function\n"));
414 utmp_nox_update(u, claim);
415#elif !defined(HAVE_UPDWTMPX)
416 /* Have utmpx.h but no "updwtmpx()". Drop to non-x stuff */
417 DEBUG(1,("utmp_update: have utmpx.h but no updwtmpx() function\n"));
418 utmp_nox_update(u, claim);
419#else
420 char *uname = NULL;
421 char *wname = NULL;
422 struct utmpx ux, *uxrc;
423
424 getutmpx(u, &ux);
425
426#if defined(HAVE_UX_UT_SYSLEN)
427 if (hostname)
428 ux.ut_syslen = strlen(hostname) + 1; /* include end NULL */
429 else
430 ux.ut_syslen = 0;
431#endif
432#if defined(HAVE_UT_UT_HOST)
433 utmp_strcpy(ux.ut_host, hostname, sizeof(ux.ut_host));
434#endif
435
436 uname = uw_pathname(talloc_tos(), "utmpx", ux_pathname);
437 wname = uw_pathname(talloc_tos(), "wtmpx", wx_pathname);
438 if (uname && wname) {
439 DEBUG(2,("utmp_update: uname:%s wname:%s\n", uname, wname));
440 }
441
442 /*
443 * Check for either uname or wname being empty.
444 * Some systems, such as Redhat 6, have a "utmpx.h" which doesn't
445 * define default filenames.
446 * Also, our local installation has not provided an override.
447 * Drop to non-x method. (E.g. RH6 has good defaults in "utmp.h".)
448 */
449 if (!uname || !wname || (strlen(uname) == 0) || (strlen(wname) == 0)) {
450 utmp_nox_update(u, claim);
451 } else {
452 utmpxname(uname);
453 setutxent();
454 uxrc = pututxline(&ux);
455 endutxent();
456 if (uxrc == NULL) {
457 DEBUG(2,("utmp_update: pututxline() failed\n"));
458 return;
459 }
460 updwtmpx(wname, &ux);
461 }
462#endif /* HAVE_UTMPX_H */
463}
464
465#if defined(HAVE_UT_UT_ID)
466/****************************************************************************
467 Encode the unique connection number into "ut_id".
468****************************************************************************/
469
470static int ut_id_encode(int i, char *fourbyte)
471{
472 int nbase;
473 const char *ut_id_encstr = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
474
475 fourbyte[0] = 'S';
476 fourbyte[1] = 'M';
477
478/*
479 * Encode remaining 2 bytes from 'i'.
480 * 'ut_id_encstr' is the character set on which modulo arithmetic is done.
481 * Example: digits would produce the base-10 numbers from '001'.
482 */
483 nbase = strlen(ut_id_encstr);
484
485 fourbyte[3] = ut_id_encstr[i % nbase];
486 i /= nbase;
487 fourbyte[2] = ut_id_encstr[i % nbase];
488 i /= nbase;
489
490 return(i); /* 0: good; else overflow */
491}
492#endif /* defined(HAVE_UT_UT_ID) */
493
494
495/*
496 fill a system utmp structure given all the info we can gather
497*/
498static bool sys_utmp_fill(struct utmp *u,
499 const char *username, const char *hostname,
500 const char *ip_addr_str,
501 const char *id_str, int id_num)
502{
503 struct timeval timeval;
504
505 /*
506 * ut_name, ut_user:
507 * Several (all?) systems seems to define one as the other.
508 * It is easier and clearer simply to let the following take its course,
509 * rather than to try to detect and optimise.
510 */
511#if defined(HAVE_UT_UT_USER)
512 utmp_strcpy(u->ut_user, username, sizeof(u->ut_user));
513#elif defined(HAVE_UT_UT_NAME)
514 utmp_strcpy(u->ut_name, username, sizeof(u->ut_name));
515#endif
516
517 /*
518 * ut_line:
519 * If size limit proves troublesome, then perhaps use "ut_id_encode()".
520 */
521 if (strlen(id_str) > sizeof(u->ut_line)) {
522 DEBUG(1,("id_str [%s] is too long for %lu char utmp field\n",
523 id_str, (unsigned long)sizeof(u->ut_line)));
524 return False;
525 }
526 utmp_strcpy(u->ut_line, id_str, sizeof(u->ut_line));
527
528#if defined(HAVE_UT_UT_PID)
529 u->ut_pid = sys_getpid();
530#endif
531
532/*
533 * ut_time, ut_tv:
534 * Some have one, some the other. Many have both, but defined (aliased).
535 * It is easier and clearer simply to let the following take its course.
536 * But note that we do the more precise ut_tv as the final assignment.
537 */
538#if defined(HAVE_UT_UT_TIME)
539 GetTimeOfDay(&timeval);
540 u->ut_time = timeval.tv_sec;
541#elif defined(HAVE_UT_UT_TV)
542 GetTimeOfDay(&timeval);
543 u->ut_tv = timeval;
544#else
545#error "with-utmp must have UT_TIME or UT_TV"
546#endif
547
548#if defined(HAVE_UT_UT_HOST)
549 utmp_strcpy(u->ut_host, hostname, sizeof(u->ut_host));
550#endif
551#if defined(HAVE_IPV6) && defined(HAVE_UT_UT_ADDR_V6)
552 memset(&u->ut_addr_v6, '\0', sizeof(u->ut_addr_v6));
553 if (ip_addr_str) {
554 struct in6_addr addr;
555 if (inet_pton(AF_INET6, ip_addr_str, &addr) > 0) {
556 memcpy(&u->ut_addr_v6, &addr, sizeof(addr));
557 }
558 }
559#elif defined(HAVE_UT_UT_ADDR)
560 memset(&u->ut_addr, '\0', sizeof(u->ut_addr));
561 if (ip_addr_str) {
562 struct in_addr addr;
563 if (inet_pton(AF_INET, ip_addr_str, &addr) > 0) {
564 memcpy(&u->ut_addr, &addr, sizeof(addr));
565 }
566 }
567 /*
568 * "(unsigned long) ut_addr" apparently exists on at least HP-UX 10.20.
569 * Volunteer to implement, please ...
570 */
571#endif
572
573#if defined(HAVE_UT_UT_ID)
574 if (ut_id_encode(id_num, u->ut_id) != 0) {
575 DEBUG(1,("utmp_fill: cannot encode id %d\n", id_num));
576 return False;
577 }
578#endif
579
580 return True;
581}
582
583/****************************************************************************
584 Close a connection.
585****************************************************************************/
586
587void sys_utmp_yield(const char *username, const char *hostname,
588 const char *ip_addr_str,
589 const char *id_str, int id_num)
590{
591 struct utmp u;
592
593 ZERO_STRUCT(u);
594
595#if defined(HAVE_UT_UT_EXIT)
596 u.ut_exit.e_termination = 0;
597 u.ut_exit.e_exit = 0;
598#endif
599
600#if defined(HAVE_UT_UT_TYPE)
601 u.ut_type = DEAD_PROCESS;
602#endif
603
604 if (!sys_utmp_fill(&u, username, hostname, ip_addr_str, id_str, id_num))
605 return;
606
607 sys_utmp_update(&u, NULL, False);
608}
609
610/****************************************************************************
611 Claim a entry in whatever utmp system the OS uses.
612****************************************************************************/
613
614void sys_utmp_claim(const char *username, const char *hostname,
615 const char *ip_addr_str,
616 const char *id_str, int id_num)
617{
618 struct utmp u;
619
620 ZERO_STRUCT(u);
621
622#if defined(HAVE_UT_UT_TYPE)
623 u.ut_type = USER_PROCESS;
624#endif
625
626 if (!sys_utmp_fill(&u, username, hostname, ip_addr_str, id_str, id_num))
627 return;
628
629 sys_utmp_update(&u, hostname, True);
630}
631
632#endif /* WITH_UTMP */
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