4.3BSD/usr/src/bin/login.c
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980 Regents of the University of California.\n\
All rights reserved.\n";
#endif not lint
#ifndef lint
static char sccsid[] = "@(#)login.c 5.15 (Berkeley) 4/12/86";
#endif not lint
/*
* 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 <sys/file.h>
#include <sgtty.h>
#include <utmp.h>
#include <signal.h>
#include <pwd.h>
#include <stdio.h>
#include <lastlog.h>
#include <errno.h>
#include <ttyent.h>
#include <syslog.h>
#include <grp.h>
#define TTYGRPNAME "tty" /* name of group to own ttys */
#define TTYGID(gid) tty_gid(gid) /* gid that owns all ttys */
#define SCMPN(a, b) strncmp(a, b, sizeof(a))
#define SCPYN(a, b) strncpy(a, b, sizeof(a))
#define NMAX sizeof(utmp.ut_name)
#define HMAX sizeof(utmp.ut_host)
#define FALSE 0
#define TRUE -1
char nolog[] = "/etc/nologin";
char qlog[] = ".hushlogin";
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] = "-";
char *envinit[] = { 0 }; /* now set by setenv calls */
/*
* 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 term[64];
struct passwd *pwd;
char *strcat(), *rindex(), *index(), *malloc(), *realloc();
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
};
struct winsize win = { 0, 0, 0, 0 };
int rflag;
int usererr = -1;
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 pflag = 0, hflag = 0, t, f, c;
int invalid, quietlog;
FILE *nlfd;
char *ttyn, *tty;
int ldisc = 0, zero = 0, i;
char **envnew;
signal(SIGALRM, timedout);
alarm(timeout);
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
setpriority(PRIO_PROCESS, 0, 0);
quota(Q_SETUID, 0, 0, 0);
/*
* -p is used by getty to tell login not to destroy the environment
* -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
*/
while (argc > 1) {
if (strcmp(argv[1], "-r") == 0) {
if (rflag || hflag) {
printf("Only one of -r and -h allowed\n");
exit(1);
}
rflag = 1;
usererr = doremotelogin(argv[2]);
SCPYN(utmp.ut_host, argv[2]);
argc -= 2;
argv += 2;
continue;
}
if (strcmp(argv[1], "-h") == 0 && getuid() == 0) {
if (rflag || hflag) {
printf("Only one of -r and -h allowed\n");
exit(1);
}
hflag = 1;
SCPYN(utmp.ut_host, argv[2]);
argc -= 2;
argv += 2;
continue;
}
if (strcmp(argv[1], "-p") == 0) {
argc--;
argv++;
pflag = 1;
continue;
}
break;
}
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);
ttyb.sg_erase = CERASE;
ttyb.sg_kill = CKILL;
ioctl(0, TIOCSLTC, <c);
ioctl(0, TIOCSETC, &tc);
ioctl(0, TIOCSETP, &ttyb);
for (t = getdtablesize(); t > 2; t--)
close(t);
ttyn = ttyname(0);
if (ttyn == (char *)0 || *ttyn == '\0')
ttyn = "/dev/tty??";
tty = rindex(ttyn, '/');
if (tty == NULL)
tty = ttyn;
else
tty++;
openlog("login", LOG_ODELAY, LOG_AUTH);
t = 0;
invalid = FALSE;
do {
ldisc = 0;
ioctl(0, TIOCSETD, &ldisc);
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 && !invalid)
SCPYN(utmp.ut_name, lusername);
else
getloginname(&utmp);
invalid = FALSE;
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 (usererr == -1 && *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(tty)) {
if (utmp.ut_host[0])
syslog(LOG_CRIT,
"ROOT LOGIN REFUSED ON %s FROM %.*s",
tty, HMAX, utmp.ut_host);
else
syslog(LOG_CRIT,
"ROOT LOGIN REFUSED ON %s", tty);
invalid = TRUE;
}
if (invalid) {
printf("Login incorrect\n");
if (++t >= 5) {
if (utmp.ut_host[0])
syslog(LOG_CRIT,
"REPEATED LOGIN FAILURES ON %s FROM %.*s, %.*s",
tty, HMAX, utmp.ut_host,
NMAX, utmp.ut_name);
else
syslog(LOG_CRIT,
"REPEATED LOGIN FAILURES ON %s, %.*s",
tty, NMAX, utmp.ut_name);
ioctl(0, TIOCHPCL, (struct sgttyb *) 0);
close(0), close(1), close(2);
sleep(10);
exit(1);
}
}
if (*pwd->pw_shell == '\0')
pwd->pw_shell = "/bin/sh";
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 (!usererr && invalid)
exit(1);
} while (invalid);
/* committed to login turn off timeout */
alarm(0);
if (quota(Q_SETUID, pwd->pw_uid, 0, 0) < 0 && errno != EINVAL) {
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("quota (Q_SETUID)");
sleep(5);
exit(0);
}
time(&utmp.ut_time);
t = ttyslot();
if (t > 0 && (f = open("/etc/utmp", O_WRONLY)) >= 0) {
lseek(f, (long)(t*sizeof(utmp)), 0);
SCPYN(utmp.ut_line, tty);
write(f, (char *)&utmp, sizeof(utmp));
close(f);
}
if ((f = open("/usr/adm/wtmp", O_WRONLY|O_APPEND)) >= 0) {
write(f, (char *)&utmp, sizeof(utmp));
close(f);
}
quietlog = access(qlog, F_OK) == 0;
if ((f = open(lastlog, O_RDWR)) >= 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, tty);
SCPYN(ll.ll_host, utmp.ut_host);
write(f, (char *) &ll, sizeof ll);
close(f);
}
chown(ttyn, pwd->pw_uid, TTYGID(pwd->pw_gid));
if (!hflag && !rflag) /* XXX */
ioctl(0, TIOCSWINSZ, &win);
chmod(ttyn, 0620);
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);
/* destroy environment unless user has asked to preserve it */
if (!pflag)
environ = envinit;
/* set up environment, this time without destruction */
/* copy the environment before setenving */
i = 0;
while (environ[i] != NULL)
i++;
envnew = (char **) malloc(sizeof (char *) * (i + 1));
for (; i >= 0; i--)
envnew[i] = environ[i];
environ = envnew;
setenv("HOME=", pwd->pw_dir, 1);
setenv("SHELL=", pwd->pw_shell, 1);
if (term[0] == '\0')
strncpy(term, stypeof(tty), sizeof(term));
setenv("TERM=", term, 0);
setenv("USER=", pwd->pw_name, 1);
setenv("PATH=", ":/usr/ucb:/bin:/usr/bin", 0);
if ((namep = rindex(pwd->pw_shell, '/')) == NULL)
namep = pwd->pw_shell;
else
namep++;
strcat(minusnam, namep);
if (tty[sizeof("tty")-1] == 'd')
syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);
if (pwd->pw_uid == 0)
if (utmp.ut_host[0])
syslog(LOG_NOTICE, "ROOT LOGIN %s FROM %.*s",
tty, HMAX, utmp.ut_host);
else
syslog(LOG_NOTICE, "ROOT LOGIN %s", tty);
if (!quietlog) {
struct stat st;
showmotd();
strcat(maildir, pwd->pw_name);
if (stat(maildir, &st) == 0 && st.st_size != 0)
printf("You have %smail.\n",
(st.st_mtime > st.st_atime) ? "new " : "");
}
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;
if ((pwd = getpwnam(lusername)) == NULL)
pwd = &nouser;
}
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 struct ttyent *t;
if ((t = getttynam(tty)) != NULL) {
if (t->ty_status & TTY_SECURE)
return (1);
}
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;
{
register struct ttyent *t;
if (ttyid == NULL || (t = getttynam(ttyid)) == NULL)
return (UNKNOWN);
return (t->ty_type);
}
doremotelogin(host)
char *host;
{
getstr(rusername, sizeof (rusername), "remuser");
getstr(lusername, sizeof (lusername), "locuser");
getstr(term, sizeof(term), "Terminal type");
if (getuid()) {
pwd = &nouser;
return(-1);
}
pwd = getpwnam(lusername);
if (pwd == NULL) {
pwd = &nouser;
return(-1);
}
return(ruserok(host, (pwd->pw_uid == 0), rusername, lusername));
}
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;
{
register char *cp = index(term, '/'), **cpp;
char *speed;
if (cp) {
*cp++ = '\0';
speed = cp;
cp = index(speed, '/');
if (cp)
*cp++ = '\0';
for (cpp = speeds; cpp < &speeds[NSPEEDS]; cpp++)
if (strcmp(*cpp, speed) == 0) {
tp->sg_ispeed = tp->sg_ospeed = cpp-speeds;
break;
}
}
tp->sg_flags = ECHO|CRMOD|ANYP|XTABS;
}
/*
* Set the value of var to be arg in the Unix 4.2 BSD environment env.
* Var should end with '='.
* (bindings are of the form "var=value")
* This procedure assumes the memory for the first level of environ
* was allocated using malloc.
*/
setenv(var, value, clobber)
char *var, *value;
{
extern char **environ;
int index = 0;
int varlen = strlen(var);
int vallen = strlen(value);
for (index = 0; environ[index] != NULL; index++) {
if (strncmp(environ[index], var, varlen) == 0) {
/* found it */
if (!clobber)
return;
environ[index] = malloc(varlen + vallen + 1);
strcpy(environ[index], var);
strcat(environ[index], value);
return;
}
}
environ = (char **) realloc(environ, sizeof (char *) * (index + 2));
if (environ == NULL) {
fprintf(stderr, "login: malloc out of memory\n");
exit(1);
}
environ[index] = malloc(varlen + vallen + 1);
strcpy(environ[index], var);
strcat(environ[index], value);
environ[++index] = NULL;
}
tty_gid(default_gid)
int default_gid;
{
struct group *getgrnam(), *gr;
int gid = default_gid;
gr = getgrnam(TTYGRPNAME);
if (gr != (struct group *) 0)
gid = gr->gr_gid;
endgrent();
return (gid);
}