xref: /netbsd/usr.bin/login/common.c (revision 6550d01e)
1 /*	$NetBSD: common.c,v 1.3 2009/12/29 20:15:15 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
5  *	The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 #include <sys/cdefs.h>
32 __RCSID("$NetBSD: common.c,v 1.3 2009/12/29 20:15:15 christos Exp $");
33 
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <sys/socket.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <stdlib.h>
41 #include <syslog.h>
42 #include <fcntl.h>
43 #include <ttyent.h>
44 #include <setjmp.h>
45 #include <time.h>
46 #include <pwd.h>
47 #include <err.h>
48 #include <vis.h>
49 #include <util.h>
50 
51 #include "pathnames.h"
52 #include "common.h"
53 
54 #if defined(KERBEROS5)
55 #define	NBUFSIZ		(MAXLOGNAME + 1 + 5)	/* .root suffix */
56 #else
57 #define	NBUFSIZ		(MAXLOGNAME + 1)
58 #endif
59 
60 #ifdef SUPPORT_UTMP
61 #include <utmp.h>
62 static void	 doutmp(void);
63 static void	 dolastlog(int);
64 #endif
65 #ifdef SUPPORT_UTMPX
66 #include <utmpx.h>
67 static void	 doutmpx(void);
68 static void	 dolastlogx(int);
69 #endif
70 
71 /*
72  * This bounds the time given to login.  Not a define so it can
73  * be patched on machines where it's too small.
74  */
75 u_int	timeout = 300;
76 
77 void	 decode_ss(const char *);
78 struct	passwd *pwd;
79 int	failures, have_ss;
80 char	term[64], *envinit[1], *hostname, *username, *tty, *nested;
81 struct timeval now;
82 struct sockaddr_storage ss;
83 
84 void
85 getloginname(void)
86 {
87 	int ch;
88 	char *p;
89 	static char nbuf[NBUFSIZ];
90 
91 	for (;;) {
92 		(void)printf("login: ");
93 		for (p = nbuf; (ch = getchar()) != '\n'; ) {
94 			if (ch == EOF) {
95 				badlogin(username);
96 				exit(EXIT_FAILURE);
97 			}
98 			if (p < nbuf + (NBUFSIZ - 1))
99 				*p++ = ch;
100 		}
101 		if (p > nbuf) {
102 			if (nbuf[0] == '-')
103 				(void)fprintf(stderr,
104 				    "login names may not start with '-'.\n");
105 			else {
106 				*p = '\0';
107 				username = nbuf;
108 				break;
109 			}
110 		}
111 	}
112 }
113 
114 int
115 rootterm(char *ttyn)
116 {
117 	struct ttyent *t;
118 
119 	return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
120 }
121 
122 static jmp_buf motdinterrupt;
123 
124 void
125 motd(char *fname)
126 {
127 	int fd, nchars;
128 	sig_t oldint;
129 	char tbuf[8192];
130 
131 	if ((fd = open(fname ? fname : _PATH_MOTDFILE, O_RDONLY, 0)) < 0)
132 		return;
133 	oldint = signal(SIGINT, sigint);
134 	if (setjmp(motdinterrupt) == 0)
135 		while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
136 			(void)write(fileno(stdout), tbuf, nchars);
137 	(void)signal(SIGINT, oldint);
138 	(void)close(fd);
139 }
140 
141 /* ARGSUSED */
142 void
143 sigint(int signo)
144 {
145 
146 	longjmp(motdinterrupt, 1);
147 }
148 
149 /* ARGSUSED */
150 void
151 timedout(int signo)
152 {
153 
154 	(void)fprintf(stderr, "Login timed out after %d seconds\n", timeout);
155 	exit(EXIT_FAILURE);
156 }
157 
158 void
159 update_db(int quietlog, int rootlogin, int fflag)
160 {
161 	struct sockaddr_storage ass;
162 	char assbuf[1024];
163 	socklen_t alen;
164 	const char *hname;
165 	int remote;
166 
167 	hname = (hostname == NULL) ? "?" : hostname;
168 	if (getpeername(STDIN_FILENO, (struct sockaddr *)&ass, &alen) != -1) {
169 		(void)sockaddr_snprintf(assbuf,
170 		    sizeof(assbuf), "%A (%a)", (void *)&ass);
171 		if (have_ss) {
172 			char ssbuf[1024];
173 			(void)sockaddr_snprintf(ssbuf,
174 			    sizeof(ssbuf), "%A(%a)", (void *)&ss);
175 			 if (memcmp(&ass, &ss, alen) != 0)
176 				syslog(LOG_NOTICE,
177 				    "login %s on tty %s address mismatch "
178 				    "passed %s != actual %s", username, tty,
179 				    ssbuf, assbuf);
180 		} else
181 			ss = ass;
182 		remote = 1;
183 	} else if (have_ss) {
184 		(void)sockaddr_snprintf(assbuf,
185 		    sizeof(assbuf), "%A(%a)", (void *)&ss);
186 		remote = 1;
187 	} else if (hostname) {
188 		(void)snprintf(assbuf, sizeof(assbuf), "? ?");
189 		remote = 1;
190 	} else
191 		remote = 0;
192 
193 	/* If fflag is on, assume caller/authenticator has logged root login. */
194 	if (rootlogin && fflag == 0) {
195 		if (remote)
196 			syslog(LOG_NOTICE, "ROOT LOGIN (%s) on tty %s from %s /"
197 			    " %s", username, tty, hname, assbuf);
198 		else
199 			syslog(LOG_NOTICE, "ROOT LOGIN (%s) on tty %s",
200 			    username, tty);
201 	} else if (nested != NULL) {
202 		if (remote)
203 			syslog(LOG_NOTICE, "%s to %s on tty %s from %s / "
204 			    "%s", nested, pwd->pw_name, tty, hname, assbuf);
205 		else
206 			syslog(LOG_NOTICE, "%s to %s on tty %s", nested,
207 			    pwd->pw_name, tty);
208 	} else {
209 		if (remote)
210 			syslog(LOG_NOTICE, "%s on tty %s from %s / %s",
211 			    pwd->pw_name, tty, hname, assbuf);
212 		else
213 			syslog(LOG_NOTICE, "%s on tty %s",
214 			    pwd->pw_name, tty);
215 	}
216 	(void)gettimeofday(&now, NULL);
217 #ifdef SUPPORT_UTMPX
218 	doutmpx();
219 	dolastlogx(quietlog);
220 	quietlog = 1;
221 #endif
222 #ifdef SUPPORT_UTMP
223 	doutmp();
224 	dolastlog(quietlog);
225 #endif
226 }
227 
228 #ifdef SUPPORT_UTMPX
229 static void
230 doutmpx(void)
231 {
232 	struct utmpx utmpx;
233 	char *t;
234 
235 	memset((void *)&utmpx, 0, sizeof(utmpx));
236 	utmpx.ut_tv = now;
237 	(void)strncpy(utmpx.ut_name, username, sizeof(utmpx.ut_name));
238 	if (hostname) {
239 		(void)strncpy(utmpx.ut_host, hostname, sizeof(utmpx.ut_host));
240 		utmpx.ut_ss = ss;
241 	}
242 	(void)strncpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
243 	utmpx.ut_type = USER_PROCESS;
244 	utmpx.ut_pid = getpid();
245 	t = tty + strlen(tty);
246 	if (t - tty >= sizeof(utmpx.ut_id)) {
247 	    (void)strncpy(utmpx.ut_id, t - sizeof(utmpx.ut_id),
248 		sizeof(utmpx.ut_id));
249 	} else {
250 	    (void)strncpy(utmpx.ut_id, tty, sizeof(utmpx.ut_id));
251 	}
252 	if (pututxline(&utmpx) == NULL)
253 		syslog(LOG_NOTICE, "Cannot update utmpx: %m");
254 	endutxent();
255 	if (updwtmpx(_PATH_WTMPX, &utmpx) != 0)
256 		syslog(LOG_NOTICE, "Cannot update wtmpx: %m");
257 }
258 
259 static void
260 dolastlogx(int quiet)
261 {
262 	struct lastlogx ll;
263 	if (!quiet && getlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != NULL) {
264 		time_t t = (time_t)ll.ll_tv.tv_sec;
265 		(void)printf("Last login: %.24s ", ctime(&t));
266 		if (*ll.ll_host != '\0')
267 			(void)printf("from %.*s ",
268 			    (int)sizeof(ll.ll_host),
269 			    ll.ll_host);
270 		(void)printf("on %.*s\n",
271 		    (int)sizeof(ll.ll_line),
272 		    ll.ll_line);
273 	}
274 	ll.ll_tv = now;
275 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
276 	if (hostname)
277 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
278 	else
279 		(void)memset(ll.ll_host, '\0', sizeof(ll.ll_host));
280 	if (have_ss)
281 		ll.ll_ss = ss;
282 	else
283 		(void)memset(&ll.ll_ss, 0, sizeof(ll.ll_ss));
284 	if (updlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != 0)
285 		syslog(LOG_NOTICE, "Cannot update lastlogx: %m");
286 }
287 #endif
288 
289 #ifdef SUPPORT_UTMP
290 static void
291 doutmp(void)
292 {
293 	struct utmp utmp;
294 
295 	(void)memset((void *)&utmp, 0, sizeof(utmp));
296 	utmp.ut_time = now.tv_sec;
297 	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
298 	if (hostname)
299 		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
300 	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
301 	login(&utmp);
302 }
303 
304 static void
305 dolastlog(int quiet)
306 {
307 	struct lastlog ll;
308 	int fd;
309 
310 	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
311 		(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
312 		if (!quiet) {
313 			if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
314 			    ll.ll_time != 0) {
315 				(void)printf("Last login: %.24s ",
316 				    ctime(&ll.ll_time));
317 				if (*ll.ll_host != '\0')
318 					(void)printf("from %.*s ",
319 					    (int)sizeof(ll.ll_host),
320 					    ll.ll_host);
321 				(void)printf("on %.*s\n",
322 				    (int)sizeof(ll.ll_line), ll.ll_line);
323 			}
324 			(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)),
325 			    SEEK_SET);
326 		}
327 		memset((void *)&ll, 0, sizeof(ll));
328 		ll.ll_time = now.tv_sec;
329 		(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
330 		if (hostname)
331 			(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
332 		(void)write(fd, (char *)&ll, sizeof(ll));
333 		(void)close(fd);
334 	}
335 }
336 #endif
337 
338 void
339 badlogin(const char *name)
340 {
341 
342 	if (failures == 0)
343 		return;
344 	if (hostname) {
345 		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
346 		    failures, failures > 1 ? "S" : "", hostname);
347 		syslog(LOG_AUTHPRIV|LOG_NOTICE,
348 		    "%d LOGIN FAILURE%s FROM %s, %s",
349 		    failures, failures > 1 ? "S" : "", hostname, name);
350 	} else {
351 		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
352 		    failures, failures > 1 ? "S" : "", tty);
353 		syslog(LOG_AUTHPRIV|LOG_NOTICE,
354 		    "%d LOGIN FAILURE%s ON %s, %s",
355 		    failures, failures > 1 ? "S" : "", tty, name);
356 	}
357 }
358 
359 const char *
360 stypeof(const char *ttyid)
361 {
362 	struct ttyent *t;
363 
364 	return (ttyid && (t = getttynam(ttyid)) ? t->ty_type : NULL);
365 }
366 
367 void
368 sleepexit(int eval)
369 {
370 
371 	(void)sleep(5);
372 	exit(eval);
373 }
374 
375 void
376 decode_ss(const char *arg)
377 {
378 	struct sockaddr_storage *ssp;
379 	size_t len = strlen(arg);
380 
381 	if (len > sizeof(*ssp) * 4 + 1 || len < sizeof(*ssp))
382 		errx(EXIT_FAILURE, "Bad argument");
383 
384 	if ((ssp = malloc(len)) == NULL)
385 		err(EXIT_FAILURE, NULL);
386 
387 	if (strunvis((char *)ssp, arg) != sizeof(*ssp))
388 		errx(EXIT_FAILURE, "Decoding error");
389 
390 	(void)memcpy(&ss, ssp, sizeof(ss));
391 	free(ssp);
392 	have_ss = 1;
393 }
394