BSD 4_1c_2 release

[unix-history] / usr / src / ucb / netser / rlogin / rlogind.c

#ifndef lint
static char sccsid[] = "@(#)rlogind.c   4.12 83/02/28";
#endif

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <errno.h>
#include <pwd.h>
#include <wait.h>
#include <signal.h>
#include <sgtty.h>
#include <stdio.h>
#include <netdb.h>

extern  errno;
int     reapchild();
struct  passwd *getpwnam();
char    *crypt(), *rindex(), *index(), *malloc(), *ntoa();
struct  sockaddr_in sin = { AF_INET };
/*
* remote login server:
*      remuser\0
*      locuser\0
*      terminal type\0
*      data
*/
main(argc, argv)
       int argc;
       char **argv;
{
       int f, options = SO_KEEPALIVE;
       struct sockaddr_in from;
       struct servent *sp;

       sp = getservbyname("login", "tcp");
       if (sp == 0) {
               fprintf(stderr, "rlogind: tcp/rlogin: unknown service\n");
               exit(1);
       }
#ifndef DEBUG
       if (fork())
               exit(0);
       for (f = 0; f < 10; f++)
               (void) close(f);
       (void) open("/", 0);
       (void) dup2(0, 1);
       (void) dup2(0, 2);
       { int tt = open("/dev/tty", 2);
         if (tt > 0) {
               ioctl(tt, TIOCNOTTY, 0);
               close(tt);
         }
       }
#endif
       sin.sin_port = sp->s_port;
       argc--, argv++;
       if (argc > 0 && !strcmp(argv[0], "-d")) {
               options |= SO_DEBUG;
               argc--, argv++;
       }
       if (argc > 0) {
               int port = atoi(argv[0]);

               if (port < 0) {
                       fprintf(stderr, "%s: bad port #\n", argv[0]);
                       exit(1);
               }
               sin.sin_port = htons((u_short)port);
               argv++, argc--;
       }
       f = socket(AF_INET, SOCK_STREAM, 0, 0);
       if (f < 0) {
               perror("rlogind: socket");
               exit(1);
       }
       if (options & SO_DEBUG)
               if (setsockopt(f, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
                       perror("rlogind: setsockopt (SO_DEBUG)");
#ifdef notdef
       if (setsockopt(f, SOL_SOCKET, SO_KEEPALIVE, 0, 0) < 0)
               perror("rlogind: setsocktopt (SO_KEEPALIVE)");
#endif
       if (bind(f, &sin, sizeof (sin), 0) < 0) {
               perror("rlogind: bind");
               exit(1);
       }
       sigset(SIGCHLD, reapchild);
       listen(f, 10);
       for (;;) {
               int s, len = sizeof (from);

               s = accept(f, &from, &len, 0);
               if (s < 0) {
                       if (errno == EINTR)
                               continue;
                       perror("rlogind: accept");
                       continue;
               }
               if (fork() == 0) {
                       signal(SIGCHLD, SIG_IGN);
                       doit(s, &from);
               }
               close(s);
       }
}

reapchild()
{
       union wait status;

       while (wait3(&status, WNOHANG, 0) > 0)
               ;
}

char    locuser[32], remuser[32];
char    buf[BUFSIZ];
int     child;
int     cleanup();
int     netf;
extern  errno;
char    *line;

doit(f, fromp)
       int f;
       struct sockaddr_in *fromp;
{
       char c;
       int i, p, cc, t, pid;
       int stop = TIOCPKT_DOSTOP;
       register struct hostent *hp;

       alarm(60);
       read(f, &c, 1);
       if (c != 0)
               exit(1);
       alarm(0);
       fromp->sin_port = htons((u_short)fromp->sin_port);
       hp = gethostbyaddr(&fromp->sin_addr, sizeof (struct in_addr),
               fromp->sin_family);
       if (hp == 0) {
               char buf[BUFSIZ], *cp = (char *)&fromp->sin_addr;

               fatal(f, sprintf(buf, "Host name for your address (%s) unknown",
                       ntoa(fromp->sin_addr)));
       }
       if (fromp->sin_family != AF_INET ||
           fromp->sin_port >= IPPORT_RESERVED ||
           hp == 0)
               fatal(f, "Permission denied");
       write(f, "", 1);
       for (c = 'p'; c <= 's'; c++) {
               struct stat stb;
               line = "/dev/ptyXX";
               line[strlen("/dev/pty")] = c;
               line[strlen("/dev/ptyp")] = '0';
               if (stat(line, &stb) < 0)
                       break;
               for (i = 0; i < 16; i++) {
                       line[strlen("/dev/ptyp")] = "0123456789abcdef"[i];
                       p = open(line, 2);
                       if (p > 0)
                               goto gotpty;
               }
       }
       fatal(f, "All network ports in use");
       /*NOTREACHED*/
gotpty:
       dup2(f, 0);
       line[strlen("/dev/")] = 't';
#ifdef DEBUG
       { int tt = open("/dev/tty", 2);
         if (tt > 0) {
               ioctl(tt, TIOCNOTTY, 0);
               close(tt);
         }
       }
#endif
       t = open(line, 2);
       if (t < 0)
               fatalperror(f, line, errno);
       { struct sgttyb b;
         gtty(t, &b); b.sg_flags = RAW|ANYP; stty(t, &b);
       }
       pid = fork();
       if (pid < 0)
               fatalperror(f, "", errno);
       if (pid) {
               char pibuf[1024], fibuf[1024], *pbp, *fbp;
               int pcc = 0, fcc = 0, on = 1;
/* FILE *console = fopen("/dev/console", "w");  */
/* setbuf(console, 0); */

/* fprintf(console, "f %d p %d\r\n", f, p); */
               ioctl(f, FIONBIO, &on);
               ioctl(p, FIONBIO, &on);
               ioctl(p, TIOCPKT, &on);
               signal(SIGTSTP, SIG_IGN);
               sigset(SIGCHLD, cleanup);
               for (;;) {
                       int ibits = 0, obits = 0;

                       if (fcc)
                               obits |= (1<<p);
                       else
                               ibits |= (1<<f);
                       if (pcc >= 0)
                               if (pcc)
                                       obits |= (1<<f);
                               else
                                       ibits |= (1<<p);
                       if (fcc < 0 && pcc < 0)
                               break;
/* fprintf(console, "ibits from %d obits from %d\r\n", ibits, obits); */
                       select(16, &ibits, &obits, 0, 0, 0);
/* fprintf(console, "ibits %d obits %d\r\n", ibits, obits); */
                       if (ibits == 0 && obits == 0) {
                               sleep(5);
                               continue;
                       }
                       if (ibits & (1<<f)) {
                               fcc = read(f, fibuf, sizeof (fibuf));
/* fprintf(console, "%d from f\r\n", fcc); */
                               if (fcc < 0 && errno == EWOULDBLOCK)
                                       fcc = 0;
                               else {
                                       if (fcc <= 0)
                                               break;
                                       fbp = fibuf;
                               }
                       }
                       if (ibits & (1<<p)) {
                               pcc = read(p, pibuf, sizeof (pibuf));
/* fprintf(console, "%d from p, buf[0] %x, errno %d\r\n", pcc, buf[0], errno); */
                               pbp = pibuf;
                               if (pcc < 0 && errno == EWOULDBLOCK)
                                       pcc = 0;
                               else if (pcc <= 0)
                                       pcc = -1;
                               else if (pibuf[0] == 0)
                                       pbp++, pcc--;
                               else {
                                       if (pibuf[0]&(TIOCPKT_FLUSHWRITE|
                                                     TIOCPKT_NOSTOP|
                                                     TIOCPKT_DOSTOP)) {
                                               int nstop = pibuf[0] &
                                                   (TIOCPKT_NOSTOP|
                                                    TIOCPKT_DOSTOP);
                                               if (nstop)
                                                       stop = nstop;
                                               pibuf[0] |= nstop;
                                               send(f,&pibuf[0],1,SOF_OOB);
                                       }
                                       pcc = 0;
                               }
                       }
                       if ((obits & (1<<f)) && pcc > 0) {
                               cc = write(f, pbp, pcc);
/* fprintf(console, "%d of %d to f\r\n", cc, pcc); */
                               if (cc > 0) {
                                       pcc -= cc;
                                       pbp += cc;
                               }
                       }
                       if ((obits & (1<<p)) && fcc > 0) {
                               cc = write(p, fbp, fcc);
/* fprintf(console, "%d of %d to p\r\n", cc, fcc); */
                               if (cc > 0) {
                                       fcc -= cc;
                                       fbp += cc;
                               }
                       }
               }
               cleanup();
       }
       close(f);
       close(p);
       dup2(t, 0);
       dup2(t, 1);
       dup2(t, 2);
       close(t);
       execl("/bin/login", "login", "-r", hp->h_name, 0);
       fatalperror(2, "/bin/login", errno);
       /*NOTREACHED*/
}

cleanup()
{

       rmut();
       vhangup();              /* XXX */
       shutdown(netf, 2);
       kill(0, SIGKILL);
       exit(1);
}

fatal(f, msg)
       int f;
       char *msg;
{
       char buf[BUFSIZ];

       buf[0] = '\01';         /* error indicator */
       (void) sprintf(buf + 1, "rlogind: %s.\n", msg);
       (void) write(f, buf, strlen(buf));
       exit(1);
}

fatalperror(f, msg, errno)
       int f;
       char *msg;
       int errno;
{
       char buf[BUFSIZ];
       extern char *sys_errlist[];

       (void) sprintf(buf, "%s: %s", msg, sys_errlist[errno]);
       fatal(f, buf);
}

#include <utmp.h>

struct  utmp wtmp;
char    wtmpf[] = "/usr/adm/wtmp";
char    utmp[] = "/etc/utmp";
#define SCPYN(a, b)     strncpy(a, b, sizeof(a))
#define SCMPN(a, b)     strncmp(a, b, sizeof(a))

rmut()
{
       register f;
       int found = 0;

       f = open(utmp, 2);
       if (f >= 0) {
               while(read(f, (char *)&wtmp, sizeof(wtmp)) == sizeof(wtmp)) {
                       if (SCMPN(wtmp.ut_line, line+5) || wtmp.ut_name[0]==0)
                               continue;
                       lseek(f, -(long)sizeof(wtmp), 1);
                       SCPYN(wtmp.ut_name, "");
                       time(&wtmp.ut_time);
                       write(f, (char *)&wtmp, sizeof(wtmp));
                       found++;
               }
               close(f);
       }
       if (found) {
               f = open(wtmpf, 1);
               if (f >= 0) {
                       SCPYN(wtmp.ut_line, line+5);
                       SCPYN(wtmp.ut_name, "");
                       time(&wtmp.ut_time);
                       lseek(f, (long)0, 2);
                       write(f, (char *)&wtmp, sizeof(wtmp));
                       close(f);
               }
       }
       chmod(line, 0666);
       chown(line, 0, 0);
       line[strlen("/dev/")] = 'p';
       chmod(line, 0666);
       chown(line, 0, 0);
}

/*
* Convert network-format internet address
* to base 256 d.d.d.d representation.
*/
char *
ntoa(in)
       struct in_addr in;
{
       static char b[18];
       register char *p;

       p = (char *)&in;
#define UC(b)   (((int)b)&0xff)
       sprintf(b, "%d.%d.%d.%d", UC(p[0]), UC(p[1]), UC(p[2]), UC(p[3]));
       return (b);
}