NFSv2/usr/src/bin/login.c
#ifndef lint
static char sccsid[] = "@(#)login.c 1.1 85/05/30 SMI"; /* from UCB 4.33 83/09/02 */
#endif
/*
* login [ name ]
* login -r hostname (for rlogind)
* login -h hostname (for telnetd, etc.)
*/
#include <sys/param.h>
#include <sys/quota.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sgtty.h>
#include <utmp.h>
#include <signal.h>
#include <pwd.h>
#include <stdio.h>
#include <lastlog.h>
#include <errno.h>
#define SCPYN(a, b) strncpy(a, b, sizeof(a))
#define NMAX sizeof(utmp.ut_name)
#define FALSE 0
#define TRUE -1
#define LOGERR /* log errors on console */
char nolog[] = "/etc/nologin";
char qlog[] = ".hushlogin";
char securetty[] = "/etc/securetty";
char maildir[30] = "/usr/spool/mail/";
char lastlog[] = "/usr/adm/lastlog";
struct passwd nouser = {"", "nope", -1, -1, -1, "", "", "", "" };
struct sgttyb ttyb;
struct utmp utmp;
char minusnam[16] = "-";
/*
* This bounds the time given to login. We initialize it here
* so it can be patched on machines where it's too small.
*/
int timeout = 60;
char homedir[64] = "HOME=";
char shell[64] = "SHELL=";
char term[64] = "TERM=";
char user[20] = "USER=";
char *envinit[] =
{ homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", term, user, 0 };
struct passwd *pwd;
struct passwd *getpwnam();
char *strcat(), *rindex(), *index();
int setpwent();
int timedout();
char *ttyname();
char *crypt();
char *getpass();
char *stypeof();
extern char **environ;
extern int errno;
struct tchars tc = {
CINTR, CQUIT, CSTART, CSTOP, CEOT, CBRK
};
struct ltchars ltc = {
CSUSP, CDSUSP, CRPRNT, CFLUSH, CWERASE, CLNEXT
};
int rflag;
char rusername[NMAX+1], lusername[NMAX+1];
char rpassword[NMAX+1];
char name[NMAX+1];
char *rhost;
main(argc, argv)
char *argv[];
{
register char *namep;
int t, f, c, i;
int invalid, quietlog;
FILE *nlfd;
char *ttyn;
int ldisc = NTTYDISC, zero = 0;
int locl = LCRTBS|LCTLECH|LDECCTQ;
signal(SIGALRM, timedout);
alarm(timeout);
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
setpriority(PRIO_PROCESS, 0, 0);
quota(Q_SETUID, 0, 0, 0);
for (t = getdtablesize(); t > 3; t--)
close(t);
/*
* -r is used by rlogind to cause the autologin protocol;
* -h is used by other servers to pass the name of the
* remote host to login so that it may be placed in utmp and wtmp
*/
if (argc > 1) {
if (strcmp(argv[1], "-r") == 0) {
rflag = doremotelogin(argv[2]);
SCPYN(utmp.ut_host, argv[2]);
argc = 0;
}
if (strcmp(argv[1], "-h") == 0 && getuid() == 0) {
SCPYN(utmp.ut_host, argv[2]);
argc = 0;
}
}
ioctl(0, TIOCLSET, &zero);
ioctl(0, TIOCNXCL, 0);
ioctl(0, FIONBIO, &zero);
ioctl(0, FIOASYNC, &zero);
ioctl(0, TIOCGETP, &ttyb);
/*
* If talking to an rlogin process,
* propagate the terminal type and
* baud rate across the network.
*/
if (rflag)
doremoteterm(term, &ttyb);
if (ttyb.sg_ospeed >= B1200)
locl |= LCRTERA|LCRTKIL;
ioctl(0, TIOCLSET, &locl);
ioctl(0, TIOCSLTC, <c);
ioctl(0, TIOCSETC, &tc);
ioctl(0, TIOCSETP, &ttyb);
ttyn = ttyname(0);
if (ttyn==(char *)0)
ttyn = "/dev/tty??";
do {
ldisc = 0;
ioctl(0, TIOCSETD, &ldisc);
invalid = FALSE;
SCPYN(utmp.ut_name, "");
/*
* Name specified, take it.
*/
if (argc > 1) {
SCPYN(utmp.ut_name, argv[1]);
argc = 0;
}
/*
* If remote login take given name,
* otherwise prompt user for something.
*/
if (rflag) {
SCPYN(utmp.ut_name, lusername);
/* autologin failed, prompt for passwd */
if (rflag == -1)
rflag = 0;
} else
getloginname(&utmp);
if (!strcmp(pwd->pw_shell, "/bin/csh")) {
ldisc = NTTYDISC;
ioctl(0, TIOCSETD, &ldisc);
}
/*
* If no remote login authentication and
* a password exists for this user, prompt
* for one and verify it.
*/
if (!rflag && *pwd->pw_passwd != '\0') {
char *pp;
setpriority(PRIO_PROCESS, 0, -4);
pp = getpass("Password:");
namep = crypt(pp, pwd->pw_passwd);
setpriority(PRIO_PROCESS, 0, 0);
if (strcmp(namep, pwd->pw_passwd))
invalid = TRUE;
}
/*
* If user not super-user, check for logins disabled.
*/
if (pwd->pw_uid != 0 && (nlfd = fopen(nolog, "r")) > 0) {
while ((c = getc(nlfd)) != EOF)
putchar(c);
fflush(stdout);
sleep(5);
exit(0);
}
/*
* If valid so far and root is logging in,
* see if root logins on this terminal are permitted.
*/
if (!invalid && pwd->pw_uid == 0 &&
!rootterm(ttyn+sizeof("/dev/")-1)) {
logerr("ROOT LOGIN REFUSED %s",
ttyn+sizeof("/dev/")-1);
invalid = TRUE;
}
if (invalid) {
printf("Login incorrect\n");
if (ttyn[sizeof("/dev/tty")-1] == 'd')
logerr("BADDIALUP %s %s",
ttyn+sizeof("/dev/")-1, utmp.ut_name);
}
if (*pwd->pw_shell == '\0')
pwd->pw_shell = "/bin/sh";
i = strlen(pwd->pw_shell);
if (chdir(pwd->pw_dir) < 0 && !invalid ) {
if (chdir("/") < 0) {
printf("No directory!\n");
invalid = TRUE;
} else {
printf("No directory! %s\n",
"Logging in with home=/");
pwd->pw_dir = "/";
}
}
/*
* Remote login invalid must have been because
* of a restriction of some sort, no extra chances.
*/
if (rflag && invalid)
exit(1);
} while (invalid);
/* committed to login turn off timeout */
alarm(0);
if (quota(Q_SETUID, pwd->pw_uid, 0, 0) < 0) {
if (errno == EUSERS)
printf("%s.\n%s.\n",
"Too many users logged on already",
"Try again later");
else if (errno == EPROCLIM)
printf("You have too many processes running.\n");
else
perror("setuid");
sleep(5);
exit(0);
}
time(&utmp.ut_time);
t = ttyslot();
if (t > 0 && (f = open("/etc/utmp", 1)) >= 0) {
lseek(f, (long)(t*sizeof(utmp)), 0);
SCPYN(utmp.ut_line, rindex(ttyn, '/')+1);
write(f, (char *)&utmp, sizeof(utmp));
close(f);
}
if (t > 0 && (f = open("/usr/adm/wtmp", 1)) >= 0) {
lseek(f, 0L, 2);
write(f, (char *)&utmp, sizeof(utmp));
close(f);
}
quietlog = access(qlog, 0) == 0;
if ((f = open(lastlog, 2)) >= 0) {
struct lastlog ll;
lseek(f, (long)pwd->pw_uid * sizeof (struct lastlog), 0);
if (read(f, (char *) &ll, sizeof ll) == sizeof ll &&
ll.ll_time != 0 && !quietlog) {
printf("Last login: %.*s ",
24-5, (char *)ctime(&ll.ll_time));
if (*ll.ll_host != '\0')
printf("from %.*s\n",
sizeof (ll.ll_host), ll.ll_host);
else
printf("on %.*s\n",
sizeof (ll.ll_line), ll.ll_line);
}
lseek(f, (long)pwd->pw_uid * sizeof (struct lastlog), 0);
time(&ll.ll_time);
SCPYN(ll.ll_line, rindex(ttyn, '/')+1);
SCPYN(ll.ll_host, utmp.ut_host);
write(f, (char *) &ll, sizeof ll);
close(f);
}
chown(ttyn, pwd->pw_uid, pwd->pw_gid);
chmod(ttyn, 0622);
setgid(pwd->pw_gid);
strncpy(name, utmp.ut_name, NMAX);
name[NMAX] = '\0';
initgroups(name, pwd->pw_gid);
quota(Q_DOWARN, pwd->pw_uid, (dev_t)-1, 0);
setuid(pwd->pw_uid);
environ = envinit;
strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
strncat(shell, pwd->pw_shell, sizeof(shell)-7);
if (term[strlen("TERM=")] == 0)
strncat(term, stypeof(ttyn), sizeof(term)-6);
strncat(user, pwd->pw_name, sizeof(user)-6);
if ((namep = rindex(pwd->pw_shell, '/')) == NULL)
namep = pwd->pw_shell;
else
namep++;
strcat(minusnam, namep);
umask(022);
if (ttyn[sizeof("/dev/tty")-1] == 'd')
logerr("DIALUP %s %s",
ttyn+sizeof("/dev/")-1, pwd->pw_name);
if (!quietlog) {
showmotd();
strcat(maildir, pwd->pw_name);
if (access(maildir,4)==0) {
struct stat statb;
stat(maildir, &statb);
if (statb.st_size)
printf("You have mail.\n");
}
}
signal(SIGALRM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGINT, SIG_DFL);
signal(SIGTSTP, SIG_IGN);
execlp(pwd->pw_shell, minusnam, 0);
perror(pwd->pw_shell);
printf("No shell\n");
exit(0);
}
getloginname(up)
register struct utmp *up;
{
register char *namep;
char c;
while (up->ut_name[0] == '\0') {
namep = up->ut_name;
printf("login: ");
while ((c = getchar()) != '\n') {
if (c == ' ')
c = '_';
if (c == EOF)
exit(0);
if (namep < up->ut_name+NMAX)
*namep++ = c;
}
}
strncpy(lusername, up->ut_name, NMAX);
lusername[NMAX] = 0;
setpwent();
if ((pwd = getpwnam(lusername)) == NULL)
pwd = &nouser;
endpwent();
}
timedout()
{
printf("Login timed out after %d seconds\n", timeout);
exit(0);
}
int stopmotd;
catch()
{
signal(SIGINT, SIG_IGN);
stopmotd++;
}
rootterm(tty)
char *tty;
{
register FILE *fd;
char buf[100];
if ((fd = fopen(securetty, "r")) == NULL)
return(1);
while (fgets(buf, sizeof buf, fd) != NULL) {
buf[strlen(buf)-1] = '\0';
if (strcmp(tty, buf) == 0) {
fclose(fd);
return(1);
}
}
fclose(fd);
return(0);
}
showmotd()
{
FILE *mf;
register c;
signal(SIGINT, catch);
if ((mf = fopen("/etc/motd","r")) != NULL) {
while ((c = getc(mf)) != EOF && stopmotd == 0)
putchar(c);
fclose(mf);
}
signal(SIGINT, SIG_IGN);
}
#undef UNKNOWN
#define UNKNOWN "su"
char *
stypeof(ttyid)
char *ttyid;
{
static char typebuf[16];
char buf[50];
register FILE *f;
register char *p, *t, *q;
if (ttyid == NULL)
return (UNKNOWN);
f = fopen("/etc/ttytype", "r");
if (f == NULL)
return (UNKNOWN);
/* split off end of name */
for (p = q = ttyid; *p != 0; p++)
if (*p == '/')
q = p + 1;
/* scan the file */
while (fgets(buf, sizeof buf, f) != NULL) {
for (t = buf; *t != ' ' && *t != '\t'; t++)
if (*t == '\0')
goto next;
*t++ = 0;
while (*t == ' ' || *t == '\t')
t++;
for (p = t; *p > ' '; p++)
;
*p = 0;
if (strcmp(q,t) == 0) {
strcpy(typebuf, buf);
fclose(f);
return (typebuf);
}
next: ;
}
fclose (f);
return (UNKNOWN);
}
doremotelogin(host)
char *host;
{
FILE *hostf;
int first = 1;
char domain[256];
if (getdomainname(domain, sizeof(domain)) < 0) {
fprintf(stderr, "login: getdomainname system call missing\n");
goto bad;
}
getstr(rusername, sizeof (rusername), "remuser");
getstr(lusername, sizeof (lusername), "locuser");
getstr(term+5, sizeof(term)-5, "Terminal type");
if (getuid()) {
pwd = &nouser;
goto bad;
}
setpwent();
pwd = getpwnam(lusername);
endpwent();
if (pwd == NULL) {
pwd = &nouser;
goto bad;
}
hostf = pwd->pw_uid ? fopen("/etc/hosts.equiv", "r") : 0;
again:
if (hostf) {
char ahost[32];
int hostmatch, usermatch;
while (fgets(ahost, sizeof (ahost), hostf)) {
char *user;
if ((user = index(ahost, '\n')) != 0)
*user++ = '\0';
if ((user = index(ahost, ' ')) != 0)
*user++ = '\0';
if (ahost[0] == '+' && ahost[1] == 0)
hostmatch = 1;
else if (ahost[0] == '+' && ahost[1] == '@')
hostmatch = innetgr(ahost + 2, host,
rusername, domain);
else if (ahost[0] == '-' && ahost[1] == '@') {
if (innetgr(ahost+2, host, rusername, domain))
break;
}
else if (ahost[0] == '-') {
if (!strcmp(host, ahost+1))
break;
}
else
hostmatch = !strcmp(host, ahost);
if (user) {
if (user[0] == '+' && user[1] == 0)
usermatch = 1;
else if (user[0] == '+' && user[1] == '@')
usermatch = innetgr(user+2, host,
rusername, domain);
else if (user[0] == '-' && user[1] == '@') {
if (innetgr(user+2, host,
rusername, domain))
break;
}
else if (user[0] == '-') {
if (!strcmp(user+1, rusername))
break;
}
else
usermatch = !strcmp(user, rusername);
}
else
usermatch = !strcmp(rusername, lusername);
if (hostmatch && usermatch) {
fclose(hostf);
return (1);
}
}
fclose(hostf);
}
if (first == 1) {
char *rhosts = ".rhosts";
struct stat sbuf;
first = 0;
if (chdir(pwd->pw_dir) < 0)
goto again;
if (lstat(rhosts, &sbuf) < 0)
goto again;
if ((sbuf.st_mode & S_IFMT) == S_IFLNK) {
printf("login: .rhosts is a soft link.\r\n");
goto bad;
}
hostf = fopen(rhosts, "r");
fstat(fileno(hostf), &sbuf);
if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) {
printf("login: Bad .rhosts ownership.\r\n");
fclose(hostf);
goto bad;
}
goto again;
}
bad:
return (-1);
}
getstr(buf, cnt, err)
char *buf;
int cnt;
char *err;
{
char c;
do {
if (read(0, &c, 1) != 1)
exit(1);
if (--cnt < 0) {
printf("%s too long\r\n", err);
exit(1);
}
*buf++ = c;
} while (c != 0);
}
char *speeds[] =
{ "0", "50", "75", "110", "134", "150", "200", "300",
"600", "1200", "1800", "2400", "4800", "9600", "19200", "38400" };
#define NSPEEDS (sizeof (speeds) / sizeof (speeds[0]))
doremoteterm(term, tp)
char *term;
struct sgttyb *tp;
{
char *cp = index(term, '/');
register int i;
if (cp) {
*cp++ = 0;
for (i = 0; i < NSPEEDS; i++)
if (!strcmp(speeds[i], cp)) {
tp->sg_ispeed = tp->sg_ospeed = i;
break;
}
}
tp->sg_flags = ECHO|CRMOD|ANYP|XTABS;
}
logerr(fmt, a1, a2, a3)
char *fmt, *a1, *a2, *a3;
{
#ifdef LOGERR
FILE *cons = fopen("/dev/console", "w");
if (cons != NULL) {
fprintf(cons, fmt, a1, a2, a3);
fprintf(cons, "\n\r");
fclose(cons);
}
#endif
}