xref: /original-bsd/usr.bin/login/login.c.1 (revision 8583c8cb) 
1static	char *sccsid = "@(#)login.c.1	4.13 (Berkeley) 4.13";
2/*
3 * login [ name ]
4 * login -r
5 */
6
7#include <sys/types.h>
8#include <sgtty.h>
9#include <utmp.h>
10#include <signal.h>
11#include <pwd.h>
12#include <stdio.h>
13#include <sys/stat.h>
14#include <lastlog.h>
15#include <whoami.h>
16#ifdef	UNAME
17#include <sys/utsname.h>
18#endif
19
20#define	SCPYN(a, b)	strncpy(a, b, sizeof(a))
21
22#define NMAX sizeof(utmp.ut_name)
23#define LMAX sizeof(utmp.ut_line)
24
25#define	FALSE	0
26#define	TRUE	-1
27
28char	nolog[] =	"/etc/nologin";
29char	qlog[]  =	".hushlogin";
30char	securetty[] =	"/etc/securetty";
31char	maildir[30] =	"/usr/spool/mail/";
32char	lastlog[] =	"/usr/adm/lastlog";
33struct	passwd nouser = {"", "nope"};
34struct	sgttyb ttyb;
35struct	utmp utmp;
36char	minusnam[16] = "-";
37
38char	homedir[64] = "HOME=";
39char	shell[64] = "SHELL=";
40char	term[64] = "TERM=";
41char	user[20] = "USER=";
42char	*speeds[] =
43    { "0", "50", "75", "110", "134", "150", "200", "300",
44      "600", "1200", "1800", "2400", "4800", "9600", "19200", "38400" };
45#define	NSPEEDS	(sizeof (speeds) / sizeof (speeds[0]))
46
47char	*envinit[] =
48    {homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", term, user, 0};
49
50struct	passwd *pwd;
51struct	passwd *getpwnam();
52char	*strcat(), *rindex(), *index();
53int	setpwent();
54char	*ttyname();
55char	*crypt();
56char	*getpass();
57char	*rindex();
58char	*stypeof();
59extern	char **environ;
60
61#define	CTRL(c)	('c'&037)
62#define	CERASE	'#'
63#define	CEOT	CTRL(d)
64#define	CKILL	'@'
65#define	CQUIT	034		/* FS, cntl shift L */
66#define	CINTR	0177		/* DEL */
67#define	CSTOP	CTRL(s)
68#define	CSTART	CTRL(q)
69#define	CBRK	0377
70struct	tchars tc = {
71	CINTR, CQUIT, CSTART, CSTOP, CEOT, CBRK
72};
73#ifdef	TIOCLSET
74struct	ltchars ltc = {
75	CTRL(z), CTRL(y), CTRL(r), CTRL(o), CTRL(w), CTRL(v)
76};
77#endif
78
79int	rflag;
80char	rusername[NMAX+1];
81char	rpassword[NMAX+1];
82
83main(argc, argv)
84char **argv;
85{
86	register char *namep;
87	int t, f, c;
88	int invalid;
89	int quietlog;
90	int i;
91	FILE *nlfd;
92	char *ttyn;
93	int	ldisc = 0;
94#ifdef	UNAME
95	struct utsname uts;
96#endif
97
98	alarm(60);
99	signal(SIGQUIT, SIG_IGN);
100	signal(SIGINT, SIG_IGN);
101	nice(-100);
102	nice(20);
103	nice(0);
104	if (argc > 0 && !strcmp(argv[1], "-r")) {
105		rflag++;
106		getstr(rusername, sizeof (rusername), "Username");
107		getstr(rpassword, sizeof (rpassword), "Password");
108		getstr(term+5, sizeof(term)-5, "Terminal type");
109	}
110#ifdef	TIOCLSET
111	ioctl(0, TIOCLSET, 0);
112#endif
113	ioctl(0, TIOCNXCL, 0);
114	gtty(0, &ttyb);
115	if (rflag) {
116		char *cp = index(term, '/');
117		if (cp) {
118			int i;
119			*cp++ = 0;
120			for (i = 0; i < NSPEEDS; i++)
121				if (!strcmp(speeds[i], cp)) {
122					ttyb.sg_ispeed = ttyb.sg_ospeed = i;
123					break;
124				}
125		}
126		ttyb.sg_flags = ECHO|CRMOD|ANYP|XTABS;
127	}
128	ttyb.sg_erase = CERASE;
129	ttyb.sg_kill = CKILL;
130	stty(0, &ttyb);
131	ioctl(0, TIOCSETC, &tc);
132#ifdef	TIOCLSET
133	ioctl(0, TIOCSLTC, &ltc);
134#endif
135	for (t=3; t<20; t++)
136		close(t);
137	ttyn = ttyname(0);
138	if (ttyn==(char *)0)
139		ttyn = "/dev/tty??";
140	do {
141		ldisc = 0;
142		ioctl(0, TIOCSETD, &ldisc);
143		invalid = FALSE;
144		SCPYN(utmp.ut_name, "");
145		if (argc>1) {
146			SCPYN(utmp.ut_name, argv[1]);
147			argc = 0;
148		}
149		if (rflag)
150			strcpy(utmp.ut_name, rusername);
151		else
152		while (utmp.ut_name[0] == '\0') {
153			namep = utmp.ut_name;
154			printf("%s login: ", sysname);
155			while ((c = getchar()) != '\n') {
156				if (c == ' ')
157					c = '_';
158				if (c == EOF)
159					exit(0);
160				if (namep < utmp.ut_name+NMAX)
161					*namep++ = c;
162			}
163		}
164		setpwent();
165		if ((pwd = getpwnam(utmp.ut_name)) == NULL)
166			pwd = &nouser;
167		endpwent();
168		if (!strcmp(pwd->pw_shell, "/bin/csh")) {
169			ldisc = NTTYDISC;
170			ioctl(0, TIOCSETD, &ldisc);
171		}
172		if (*pwd->pw_passwd != '\0') {
173			char *pp;
174			nice(-4);
175			if (rflag == 0)
176				pp = getpass("Password:");
177			else
178				pp = rpassword;
179			namep = crypt(pp,pwd->pw_passwd);
180			nice(4);
181			if (strcmp(namep, pwd->pw_passwd))
182				invalid = TRUE;
183		}
184		if (pwd->pw_uid != 0 && (nlfd = fopen(nolog, "r")) > 0) {
185			/* logins are disabled except for root */
186			while ((c = getc(nlfd)) != EOF)
187				putchar(c);
188			fflush(stdout);
189			sleep(5);
190			exit(0);
191		}
192		if (!invalid && pwd->pw_uid == 0 &&
193		    !rootterm(ttyn+sizeof("/dev/")-1)) {
194			FILE *console = fopen("/dev/console", "w");
195			if (console != NULL) {
196				fprintf(console, "\r\nROOT LOGIN REFUSED %s\r\n"
197				    , ttyn+sizeof("/dev/")-1
198				);
199				fclose(console);
200			}
201			invalid = TRUE;
202		}
203		if (invalid) {
204			printf("Login incorrect\n");
205			if (ttyn[sizeof("/dev/tty")-1] == 'd') {
206				FILE *console = fopen("/dev/console", "w");
207				if (console != NULL) {
208					fprintf(console, "\r\nBADDIALUP %s %s\r\n"
209					    , ttyn+sizeof("/dev/")-1
210					    , utmp.ut_name);
211					fclose(console);
212				}
213			}
214		}
215		if (*pwd->pw_shell == '\0')
216			pwd->pw_shell = "/bin/sh";
217		i = strlen(pwd->pw_shell);
218		if (chdir(pwd->pw_dir) < 0 && !invalid ) {
219			if (chdir("/") < 0) {
220				printf("No directory!\n");
221				invalid = TRUE;
222			} else {
223				printf("No directory!  Logging in with home=/\n");
224				pwd->pw_dir = "/";
225			}
226		}
227		if (rflag && invalid)
228			exit(1);
229	} while (invalid);
230
231
232	time(&utmp.ut_time);
233	t = ttyslot();
234	if (t>0 && (f = open("/etc/utmp", 1)) >= 0) {
235		lseek(f, (long)(t*sizeof(utmp)), 0);
236		SCPYN(utmp.ut_line, rindex(ttyn, '/')+1);
237		write(f, (char *)&utmp, sizeof(utmp));
238		close(f);
239	}
240	if (t>0 && (f = open("/usr/adm/wtmp", 1)) >= 0) {
241		lseek(f, 0L, 2);
242		write(f, (char *)&utmp, sizeof(utmp));
243		close(f);
244	}
245	quietlog = FALSE;
246	if (access(qlog, 0) == 0)
247		quietlog = TRUE;
248	if ( !quietlog && (f = open(lastlog, 2)) >= 0 ) {
249		struct lastlog ll;
250
251		lseek(f, (long)pwd->pw_uid * sizeof (struct lastlog), 0);
252		if (read(f, (char *) &ll, sizeof ll) == sizeof ll &&
253		    ll.ll_time != 0) {
254			printf("Last login: %.*s on %.*s\n"
255			    , 24-5
256			    , (char *) ctime(&ll.ll_time)
257			    , sizeof(ll.ll_line)
258			    , ll.ll_line
259			);
260		}
261		lseek(f, (long)pwd->pw_uid * sizeof (struct lastlog), 0);
262		time(&ll.ll_time);
263		SCPYN(ll.ll_line, rindex(ttyn, '/')+1);
264		write(f, (char *) &ll, sizeof ll);
265		close(f);
266	}
267	chown(ttyn, pwd->pw_uid, pwd->pw_gid);
268	setgid(pwd->pw_gid);
269	inigrp(utmp.ut_name, pwd->pw_gid);
270	setuid(pwd->pw_uid);
271	environ = envinit;
272	strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
273	strncat(shell, pwd->pw_shell, sizeof(shell)-7);
274	if (rflag == 0)
275		strncat(term, stypeof(ttyn), sizeof(term)-6);
276	strncat(user, pwd->pw_name, sizeof(user)-6);
277	if ((namep = rindex(pwd->pw_shell, '/')) == NULL)
278		namep = pwd->pw_shell;
279	else
280		namep++;
281	strcat(minusnam, namep);
282	alarm(0);
283#ifdef ARPAVAX
284	if (pwd->pw_gid == 27)			/* UGLY ! */
285		umask(2);
286	else
287#endif
288		umask(022);
289	if (ttyn[sizeof("/dev/tty")-1] == 'd') {
290		FILE *console = fopen("/dev/console", "w");
291		if (console != NULL) {
292			fprintf(console, "\r\nDIALUP %s %s\r\n"
293			    , ttyn+sizeof("/dev/")-1
294			    , pwd->pw_name
295			);
296			fclose(console);
297		}
298	}
299	if ( !quietlog ) {
300		showmotd();
301		strcat(maildir, pwd->pw_name);
302		if (access(maildir,4)==0) {
303			struct stat statb;
304			stat(maildir, &statb);
305			if (statb.st_size)
306				printf("You have mail.\n");
307		}
308	}
309
310	signal(SIGQUIT, SIG_DFL);
311	signal(SIGINT, SIG_DFL);
312	signal(SIGTSTP, SIG_IGN);
313	execlp(pwd->pw_shell, minusnam, 0);
314	perror(pwd->pw_shell);
315	printf("No shell\n");
316	exit(0);
317}
318
319int	stopmotd;
320catch()
321{
322	signal(SIGINT, SIG_IGN);
323	stopmotd++;
324}
325
326/*
327 * return true if OK for root to login on this terminal
328 */
329rootterm(tty)
330	char	*tty;
331{
332	register FILE *fd;
333	char	buf[100];
334
335	if ((fd = fopen(securetty, "r")) == NULL)
336		return(1);
337	while (fgets(buf, sizeof buf, fd) != NULL) {
338		buf[strlen(buf)-1] = '\0';
339		if (strcmp(tty, buf) == 0) {
340			fclose(fd);
341			return(1);
342		}
343	}
344	fclose(fd);
345	return(0);
346}
347
348showmotd()
349{
350	FILE *mf;
351	register c;
352
353	signal(SIGINT, catch);
354	if ((mf = fopen("/etc/motd","r")) != NULL) {
355		while ((c = getc(mf)) != EOF && stopmotd == 0)
356			putchar(c);
357		fclose(mf);
358	}
359	signal(SIGINT, SIG_IGN);
360}
361
362#undef	UNKNOWN
363#define UNKNOWN "su"
364
365char *
366stypeof(ttyid)
367char	*ttyid;
368{
369	static char	typebuf[16];
370	char		buf[50];
371	register FILE	*f;
372	register char	*p, *t, *q;
373
374	if (ttyid == NULL)
375		return (UNKNOWN);
376	f = fopen("/etc/ttytype", "r");
377	if (f == NULL)
378		return (UNKNOWN);
379	/* split off end of name */
380	for (p = q = ttyid; *p != 0; p++)
381		if (*p == '/')
382			q = p + 1;
383
384	/* scan the file */
385	while (fgets(buf, sizeof buf, f) != NULL)
386	{
387		for (t=buf; *t!=' ' && *t != '\t'; t++)
388			;
389		*t++ = 0;
390		while (*t == ' ' || *t == '\t')
391			t++;
392		for (p=t; *p>' '; p++)
393			;
394		*p = 0;
395		if (strcmp(q,t)==0) {
396			strcpy(typebuf, buf);
397			fclose(f);
398			return (typebuf);
399		}
400	}
401	fclose (f);
402	return (UNKNOWN);
403}
404
405getstr(buf, cnt, err)
406	char *buf;
407	int cnt;
408	char *err;
409{
410	char c;
411
412	do {
413		if (read(0, &c, 1) != 1)
414			exit(1);
415		if (--cnt < 0) {
416			printf("%s too long\r\n", err);
417			exit(1);
418		}
419		*buf++ = c;
420	} while (c != 0);
421}
422