xref: /netbsd/usr.bin/login/common.c (revision 3dacdfcd)
1 /*	$NetBSD: common.c,v 1.8 2015/10/28 07:27:24 shm 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 1.8 2015/10/28 07:27:24 shm 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, *tty, *nested;
81 const char *username;
82 struct timeval now;
83 struct sockaddr_storage ss;
84 
85 char *
trimloginname(char * u)86 trimloginname(char *u)
87 {
88 	if (strlen(u) > MAXLOGNAME)
89 		u[MAXLOGNAME] = '\0';
90 	return u;
91 }
92 
93 char *
getloginname(void)94 getloginname(void)
95 {
96 	int ch;
97 	char *p;
98 	static char nbuf[NBUFSIZ];
99 
100 	for (;;) {
101 		(void)printf("login: ");
102 		for (p = nbuf; (ch = getchar()) != '\n'; ) {
103 			if (ch == EOF) {
104 				badlogin(username);
105 				exit(EXIT_FAILURE);
106 			}
107 			if (p < nbuf + (NBUFSIZ - 1))
108 				*p++ = ch;
109 		}
110 		if (p > nbuf) {
111 			if (nbuf[0] == '-')
112 				(void)fprintf(stderr,
113 				    "login names may not start with '-'.\n");
114 			else {
115 				*p = '\0';
116 				return nbuf;
117 			}
118 		}
119 	}
120 }
121 
122 int
rootterm(char * ttyn)123 rootterm(char *ttyn)
124 {
125 	struct ttyent *t;
126 
127 	return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
128 }
129 
130 static jmp_buf motdinterrupt;
131 
132 void
motd(const char * fname)133 motd(const char *fname)
134 {
135 	int fd, nchars;
136 	sig_t oldint;
137 	char tbuf[8192];
138 
139 	if ((fd = open(fname ? fname : _PATH_MOTDFILE, O_RDONLY, 0)) < 0)
140 		return;
141 	oldint = signal(SIGINT, sigint);
142 	if (setjmp(motdinterrupt) == 0)
143 		while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
144 			(void)write(fileno(stdout), tbuf, nchars);
145 	(void)signal(SIGINT, oldint);
146 	(void)close(fd);
147 }
148 
149 /* ARGSUSED */
150 void __dead
sigint(int signo)151 sigint(int signo)
152 {
153 
154 	longjmp(motdinterrupt, 1);
155 }
156 
157 /* ARGSUSED */
158 void __dead
timedout(int signo)159 timedout(int signo)
160 {
161 
162 	(void)fprintf(stderr, "Login timed out after %d seconds\n", timeout);
163 	exit(EXIT_FAILURE);
164 }
165 
166 void
update_db(int quietlog,int rootlogin,int fflag)167 update_db(int quietlog, int rootlogin, int fflag)
168 {
169 	struct sockaddr_storage ass;
170 	char assbuf[1024];
171 	socklen_t alen;
172 	const char *hname;
173 	int remote;
174 
175 	hname = (hostname == NULL) ? "?" : hostname;
176 	alen = sizeof(ass);
177 	if (getpeername(STDIN_FILENO, (struct sockaddr *)&ass, &alen) != -1) {
178 		(void)sockaddr_snprintf(assbuf,
179 		    sizeof(assbuf), "%A (%a)", (void *)&ass);
180 		if (have_ss) {
181 			char ssbuf[1024];
182 			(void)sockaddr_snprintf(ssbuf,
183 			    sizeof(ssbuf), "%A(%a)", (void *)&ss);
184 			 if (memcmp(&ass, &ss, alen) != 0)
185 				syslog(LOG_NOTICE,
186 				    "login %s on tty %s address mismatch "
187 				    "passed %s != actual %s", username, tty,
188 				    ssbuf, assbuf);
189 		} else
190 			ss = ass;
191 		remote = 1;
192 	} else if (have_ss) {
193 		(void)sockaddr_snprintf(assbuf,
194 		    sizeof(assbuf), "%A(%a)", (void *)&ss);
195 		remote = 1;
196 	} else if (hostname) {
197 		(void)snprintf(assbuf, sizeof(assbuf), "? ?");
198 		remote = 1;
199 	} else
200 		remote = 0;
201 
202 	/* If fflag is on, assume caller/authenticator has logged root login. */
203 	if (rootlogin && fflag == 0) {
204 		if (remote)
205 			syslog(LOG_NOTICE, "ROOT LOGIN (%s) on tty %s from %s /"
206 			    " %s", username, tty, hname, assbuf);
207 		else
208 			syslog(LOG_NOTICE, "ROOT LOGIN (%s) on tty %s",
209 			    username, tty);
210 	} else if (nested != NULL) {
211 		if (remote)
212 			syslog(LOG_NOTICE, "%s to %s on tty %s from %s / "
213 			    "%s", nested, pwd->pw_name, tty, hname, assbuf);
214 		else
215 			syslog(LOG_NOTICE, "%s to %s on tty %s", nested,
216 			    pwd->pw_name, tty);
217 	} else {
218 		if (remote)
219 			syslog(LOG_NOTICE, "%s on tty %s from %s / %s",
220 			    pwd->pw_name, tty, hname, assbuf);
221 		else
222 			syslog(LOG_NOTICE, "%s on tty %s",
223 			    pwd->pw_name, tty);
224 	}
225 	(void)gettimeofday(&now, NULL);
226 #ifdef SUPPORT_UTMPX
227 	doutmpx();
228 	dolastlogx(quietlog);
229 	quietlog = 1;
230 #endif
231 #ifdef SUPPORT_UTMP
232 	doutmp();
233 	dolastlog(quietlog);
234 #endif
235 }
236 
237 #ifdef SUPPORT_UTMPX
238 static void
doutmpx(void)239 doutmpx(void)
240 {
241 	struct utmpx utmpx;
242 	char *t;
243 
244 	memset((void *)&utmpx, 0, sizeof(utmpx));
245 	utmpx.ut_tv = now;
246 	(void)strncpy(utmpx.ut_name, username, sizeof(utmpx.ut_name));
247 	if (hostname) {
248 		(void)strncpy(utmpx.ut_host, hostname, sizeof(utmpx.ut_host));
249 		utmpx.ut_ss = ss;
250 	}
251 	(void)strncpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
252 	utmpx.ut_type = USER_PROCESS;
253 	utmpx.ut_pid = getpid();
254 	t = tty + strlen(tty);
255 	if ((size_t)(t - tty) >= sizeof(utmpx.ut_id)) {
256 	    (void)strncpy(utmpx.ut_id, t - sizeof(utmpx.ut_id),
257 		sizeof(utmpx.ut_id));
258 	} else {
259 	    (void)strncpy(utmpx.ut_id, tty, sizeof(utmpx.ut_id));
260 	}
261 	if (pututxline(&utmpx) == NULL)
262 		syslog(LOG_NOTICE, "Cannot update utmpx: %m");
263 	endutxent();
264 	if (updwtmpx(_PATH_WTMPX, &utmpx) != 0)
265 		syslog(LOG_NOTICE, "Cannot update wtmpx: %m");
266 }
267 
268 static void
dolastlogx(int quiet)269 dolastlogx(int quiet)
270 {
271 	struct lastlogx ll;
272 	if (!quiet && getlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != NULL) {
273 		time_t t = (time_t)ll.ll_tv.tv_sec;
274 		(void)printf("Last login: %.24s ", ctime(&t));
275 		if (*ll.ll_host != '\0')
276 			(void)printf("from %.*s ",
277 			    (int)sizeof(ll.ll_host),
278 			    ll.ll_host);
279 		(void)printf("on %.*s\n",
280 		    (int)sizeof(ll.ll_line),
281 		    ll.ll_line);
282 	}
283 	ll.ll_tv = now;
284 	(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
285 	if (hostname)
286 		(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
287 	else
288 		(void)memset(ll.ll_host, '\0', sizeof(ll.ll_host));
289 	if (have_ss)
290 		ll.ll_ss = ss;
291 	else
292 		(void)memset(&ll.ll_ss, 0, sizeof(ll.ll_ss));
293 	if (updlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != 0)
294 		syslog(LOG_NOTICE, "Cannot update lastlogx: %m");
295 }
296 #endif
297 
298 #ifdef SUPPORT_UTMP
299 static void
doutmp(void)300 doutmp(void)
301 {
302 	struct utmp utmp;
303 
304 	(void)memset((void *)&utmp, 0, sizeof(utmp));
305 	utmp.ut_time = now.tv_sec;
306 	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
307 	if (hostname)
308 		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
309 	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
310 	login(&utmp);
311 }
312 
313 static void
dolastlog(int quiet)314 dolastlog(int quiet)
315 {
316 	struct lastlog ll;
317 	int fd;
318 
319 	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
320 		(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
321 		if (!quiet) {
322 			if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
323 			    ll.ll_time != 0) {
324 				(void)printf("Last login: %.24s ",
325 				    ctime(&ll.ll_time));
326 				if (*ll.ll_host != '\0')
327 					(void)printf("from %.*s ",
328 					    (int)sizeof(ll.ll_host),
329 					    ll.ll_host);
330 				(void)printf("on %.*s\n",
331 				    (int)sizeof(ll.ll_line), ll.ll_line);
332 			}
333 			(void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)),
334 			    SEEK_SET);
335 		}
336 		memset((void *)&ll, 0, sizeof(ll));
337 		ll.ll_time = now.tv_sec;
338 		(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
339 		if (hostname)
340 			(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
341 		(void)write(fd, (char *)&ll, sizeof(ll));
342 		(void)close(fd);
343 	}
344 }
345 #endif
346 
347 void
badlogin(const char * name)348 badlogin(const char *name)
349 {
350 
351 	if (failures == 0)
352 		return;
353 	if (hostname) {
354 		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
355 		    failures, failures > 1 ? "S" : "", hostname);
356 		syslog(LOG_AUTHPRIV|LOG_NOTICE,
357 		    "%d LOGIN FAILURE%s FROM %s, %s",
358 		    failures, failures > 1 ? "S" : "", hostname, name);
359 	} else {
360 		syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
361 		    failures, failures > 1 ? "S" : "", tty);
362 		syslog(LOG_AUTHPRIV|LOG_NOTICE,
363 		    "%d LOGIN FAILURE%s ON %s, %s",
364 		    failures, failures > 1 ? "S" : "", tty, name);
365 	}
366 }
367 
368 const char *
stypeof(const char * ttyid)369 stypeof(const char *ttyid)
370 {
371 	struct ttyent *t;
372 
373 	return (ttyid && (t = getttynam(ttyid)) ? t->ty_type : NULL);
374 }
375 
376 void __dead
sleepexit(int eval)377 sleepexit(int eval)
378 {
379 
380 	(void)sleep(5);
381 	exit(eval);
382 }
383 
384 void
decode_ss(const char * arg)385 decode_ss(const char *arg)
386 {
387 	struct sockaddr_storage *ssp;
388 	size_t len = strlen(arg);
389 
390 	if (len > sizeof(*ssp) * 4 + 1 || len < sizeof(*ssp))
391 		errx(EXIT_FAILURE, "Bad argument");
392 
393 	if ((ssp = malloc(len + 1)) == NULL)
394 		err(EXIT_FAILURE, NULL);
395 
396 	if (strunvis((char *)ssp, arg) != sizeof(*ssp))
397 		errx(EXIT_FAILURE, "Decoding error");
398 
399 	(void)memcpy(&ss, ssp, sizeof(ss));
400 	free(ssp);
401 	have_ss = 1;
402 }
403