specify if mail in the mbox is new

[unix-history] / usr / src / usr.bin / login / login.c

#ifndef lint
static  char *sccsid = "@(#)login.c     4.35 (Berkeley) 85/01/08";
#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 <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>

#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 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] = "-";
/*
* 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;
char    *strcat(), *rindex(), *index();
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;
       int invalid, quietlog;
       FILE *nlfd;
       char *ttyn, *tty;
       int ldisc = 0, zero = 0;

       signal(SIGALRM, timedout);
       alarm(timeout);
       signal(SIGQUIT, SIG_IGN);
       signal(SIGINT, SIG_IGN);
       setpriority(PRIO_PROCESS, 0, 0);
       quota(Q_SETUID, 0, 0, 0);
       /*
        * -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);
       ioctl(0, TIOCSLTC, &ltc);
       ioctl(0, TIOCSETC, &tc);
       ioctl(0, TIOCSETP, &ttyb);
       for (t = getdtablesize(); t > 3; t--)
               close(t);
       ttyn = ttyname(0);
       if (ttyn == (char *)0)
               ttyn = "/dev/tty??";
       tty = rindex(ttyn, '/');
       if (tty == NULL)
               tty = ttyn;
       else
               tty++;
       openlog("login", 0, 0);
       t = 0;
       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(tty)) {
                       syslog(LOG_INFO, "ROOT LOGIN REFUSED %s", tty);
                       invalid = TRUE;
               }
               if (invalid) {
                       printf("Login incorrect\n");
                       if (++t >= 5) {
                               syslog(LOG_INFO,
                                   "REPEATED LOGIN FAILURES %s, %s",
                                       tty, 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 (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("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, 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[sizeof("TERM=")-1] == 0)
               strncat(term, stypeof(tty), 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);
       if (tty[sizeof("tty")-1] == 'd')
               syslog(LOG_INFO, "DIALUP %s %s", tty, pwd->pw_name);
       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;
{
       FILE *hostf;
       int first = 1;

       getstr(rusername, sizeof (rusername), "remuser");
       getstr(lusername, sizeof (lusername), "locuser");
       getstr(term+5, sizeof(term)-5, "Terminal type");
       if (getuid()) {
               pwd = &nouser;
               goto bad;
       }
       pwd = getpwnam(lusername);
       if (pwd == NULL) {
               pwd = &nouser;
               goto bad;
       }
       hostf = pwd->pw_uid ? fopen("/etc/hosts.equiv", "r") : 0;
again:
       if (hostf) {
               char ahost[32];

               while (fgets(ahost, sizeof (ahost), hostf)) {
                       char *user;

                       if ((user = index(ahost, '\n')) != 0)
                               *user++ = '\0';
                       if ((user = index(ahost, ' ')) != 0)
                               *user++ = '\0';
                       if (!strcmp(host, ahost) &&
                           !strcmp(rusername, user ? user : lusername)) {
                               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;
}