455 lines
9.3 KiB
C
455 lines
9.3 KiB
C
/*
|
|
rlogind.c
|
|
|
|
Created: by Philip Homburg <philip@cs.vu.nl>
|
|
Log: Utmp improvement by Kees Bot <kjb@cs.vu.nl>
|
|
Split to compile easier on i86 by kjb
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/ioctl.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <termios.h>
|
|
#include <time.h>
|
|
#include <unistd.h>
|
|
#include <utmp.h>
|
|
#include <net/hton.h>
|
|
#define EXTERN
|
|
#include "rlogind.h"
|
|
|
|
char pty_str[]= "/dev/ptyXX";
|
|
char tty_str[]= "/dev/ttyXX";
|
|
char hex_str[16]= "0123456789abcdef";
|
|
|
|
char PATH_UTMP[] = "/etc/utmp"; /* current logins */
|
|
char PATH_WTMP[] = "/usr/adm/wtmp"; /* login/logout history */
|
|
|
|
char term[64]= "TERM=";
|
|
#define ENVSIZE (sizeof("TERM=")-1) /* skip null for concatenation. */
|
|
int confirmed= 0;
|
|
char *env[2];
|
|
char *args[10];
|
|
|
|
static void do_child(int tty_fd, char *tty_str);
|
|
static void dealloc_term(int slot, char *tty_str, int pid);
|
|
static void wtmp(char *user, char *id, char *line, int pid, int type, int slot);
|
|
static void setup_term(int fd);
|
|
static speed_t num2speed(int num);
|
|
static int do_control(char *buf, int cnt);
|
|
static void readall(char *buf, int cnt);
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
int error;
|
|
int i, j= 0;
|
|
int tty_fd, pty_fd;
|
|
int login_pid, write_pid;
|
|
int count, bytes, tmp_count;
|
|
char *lp= 0, *cp;
|
|
struct stat struct_stat;
|
|
int slot;
|
|
|
|
prog_name= argv[0];
|
|
|
|
/* Check if the remote user is allowed in. */
|
|
authenticate();
|
|
|
|
write(1, "", 1); /* Send the '\0' */
|
|
confirmed= 1;
|
|
|
|
/* We try to convince the other side not the do ^S/^Q, the rlogin
|
|
* protocol indicates the we only send this when XOFF is turned off
|
|
* but we don't know when this happens so we tell the other side that
|
|
* it is turned off.
|
|
*/
|
|
tcp_urg(1, 1);
|
|
|
|
write(1, "\220", 1);
|
|
|
|
tcp_urg(1, 0);
|
|
|
|
/* Let's look for a pty. */
|
|
pty_fd= -1;
|
|
for (i= 'p'; i <= 'z'; i++)
|
|
{
|
|
pty_str[sizeof(pty_str)-3]= i;
|
|
pty_str[sizeof(pty_str)-2]= '0';
|
|
error= stat(pty_str, &struct_stat);
|
|
if (error == -1)
|
|
continue;
|
|
for (j= 0; j < 16; j++)
|
|
{
|
|
pty_str[sizeof(pty_str)-2]= hex_str[j];
|
|
pty_fd= open(pty_str, O_RDWR);
|
|
if (pty_fd != -1)
|
|
break;
|
|
}
|
|
if (pty_fd != -1)
|
|
break;
|
|
}
|
|
if (pty_fd == -1)
|
|
{
|
|
printf("%s: out of ptys\r\n", prog_name);
|
|
exit(1);
|
|
}
|
|
tty_str[sizeof(pty_str)-3]= i;
|
|
tty_str[sizeof(pty_str)-2]= hex_str[j];
|
|
|
|
tty_fd= open(tty_str, O_RDWR);
|
|
if (tty_fd == -1)
|
|
{
|
|
printf("%s: unable to open '%s': %s\r\n", prog_name, tty_str,
|
|
strerror(errno));
|
|
exit(1);
|
|
}
|
|
|
|
slot= fttyslot(tty_fd);
|
|
|
|
login_pid= fork();
|
|
if (login_pid == -1)
|
|
{
|
|
printf("%s: unable to fork: %s\r\n", prog_name,
|
|
strerror(errno));
|
|
exit(1);
|
|
}
|
|
if (login_pid == 0)
|
|
{
|
|
close(pty_fd);
|
|
wtmp("", "", tty_str, login_pid, LOGIN_PROCESS, slot);
|
|
do_child(tty_fd, tty_str);
|
|
}
|
|
close(tty_fd);
|
|
|
|
write_pid= fork();
|
|
if (write_pid == -1)
|
|
{
|
|
printf("%s: unable to fork: %s\r\n", prog_name,
|
|
strerror(errno));
|
|
exit(1);
|
|
}
|
|
if (write_pid == 0)
|
|
{
|
|
dup2(pty_fd, 0);
|
|
count= 0;
|
|
for (;;)
|
|
{
|
|
if (!count)
|
|
{
|
|
count= read(0, line, sizeof(line));
|
|
if (count <= 0)
|
|
break;
|
|
lp= line;
|
|
}
|
|
bytes= write(1, lp, count);
|
|
if (bytes <= 0 || bytes > count)
|
|
break;
|
|
lp += bytes;
|
|
count -= bytes;
|
|
}
|
|
kill(getppid(), SIGKILL);
|
|
dealloc_term(slot, tty_str, login_pid);
|
|
_exit(1);
|
|
}
|
|
|
|
dup2(pty_fd, 1);
|
|
count= 0;
|
|
for (;;)
|
|
{
|
|
if (!count)
|
|
{
|
|
count= read(0, line, sizeof(line));
|
|
if (count <= 0)
|
|
break;
|
|
lp= line;
|
|
}
|
|
tmp_count= count;
|
|
cp= memchr(lp, 255, count);
|
|
if (cp)
|
|
{
|
|
tmp_count= cp-lp;
|
|
if (tmp_count == 0)
|
|
{
|
|
tmp_count= do_control(lp, count);
|
|
if (tmp_count)
|
|
{
|
|
lp += tmp_count;
|
|
count -= tmp_count;
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
bytes= write(1, lp, tmp_count);
|
|
if (bytes <= 0 || bytes > count)
|
|
break;
|
|
lp += bytes;
|
|
count -= bytes;
|
|
}
|
|
kill(write_pid, SIGKILL);
|
|
dealloc_term(slot, tty_str, login_pid);
|
|
return(0);
|
|
}
|
|
|
|
static void do_child(int tty_fd, char *tty_str)
|
|
{
|
|
int ctty_fd, tst_fd;
|
|
FILE *tty_file;
|
|
int sav_errno;
|
|
char **argp;
|
|
|
|
/* Set up the terminal attributes. */
|
|
setup_term(tty_fd);
|
|
|
|
/* Let's start the new session. */
|
|
setsid();
|
|
ctty_fd= open(tty_str, O_RDWR);
|
|
if (ctty_fd == -1)
|
|
{
|
|
printf("%s(do_child): unable to open '%s': %s\r\n",
|
|
prog_name, tty_str, strerror(errno));
|
|
exit(1);
|
|
}
|
|
/* Test if we really got a controlling tty. */
|
|
tst_fd= open("/dev/tty", O_RDWR);
|
|
if (tst_fd == -1)
|
|
{
|
|
printf(
|
|
"%s(do_child): '%s' didn't result in a controlling tty (%s)\r\n",
|
|
prog_name, tty_str, strerror(errno));
|
|
exit(1);
|
|
}
|
|
|
|
argp= args;
|
|
*argp++= "login";
|
|
*argp++= "-p";
|
|
*argp++= "-h";
|
|
*argp++= hostname;
|
|
if (authenticated)
|
|
*argp++= "-f";
|
|
if (lusername[0] != '\0')
|
|
*argp++= lusername;
|
|
|
|
/* We reached the point of no return. */
|
|
close(tst_fd);
|
|
close(tty_fd);
|
|
|
|
if (ctty_fd != 0)
|
|
{
|
|
dup2(ctty_fd, 0);
|
|
close(ctty_fd);
|
|
ctty_fd= 0;
|
|
}
|
|
dup2(ctty_fd, 1);
|
|
#if DEBUG
|
|
fprintf(stderr, "execing login\r\n");
|
|
#endif
|
|
dup2(ctty_fd, 2);
|
|
execve("/bin/login", args, env);
|
|
if (errno == ENOENT) execve("/usr/bin/login", args, env);
|
|
sav_errno= errno;
|
|
tty_file= fdopen(2, "w");
|
|
if (tty_file)
|
|
{
|
|
fprintf(tty_file, "%s(do_child): unable to exec login: %s\r\n",
|
|
prog_name, strerror(sav_errno));
|
|
fflush(tty_file);
|
|
}
|
|
_exit(1);
|
|
}
|
|
|
|
static void dealloc_term(int slot, char *tty_str, int pid)
|
|
{
|
|
wtmp("", "", tty_str, pid, DEAD_PROCESS, slot);
|
|
|
|
/* Finally we reset the owner and mode of the terminal. */
|
|
chown(tty_str, 0, 0);
|
|
chmod(tty_str, 0666);
|
|
}
|
|
|
|
static void wtmp(
|
|
char *user, /* name of user */
|
|
char *id, /* inittab ID */
|
|
char *line, /* TTY name */
|
|
int pid, /* PID of process */
|
|
int type, /* TYPE of entry */
|
|
int slot) /* slot number in UTMP */
|
|
{
|
|
/* Log an event into the UTMP and WTMP files. */
|
|
|
|
struct utmp utmp; /* UTMP/WTMP User Accounting */
|
|
int fd= -1;
|
|
int log = 1; /* log in wtmp */
|
|
char *p;
|
|
|
|
/* Strip the /dev part of the TTY name. */
|
|
p = strrchr(line, '/');
|
|
if (p != 0)
|
|
line= p+1;
|
|
|
|
if (type == DEAD_PROCESS) {
|
|
/* Don't add a logout entry for just a dying login. */
|
|
if ((fd = open(PATH_UTMP, O_RDONLY)) < 0) return;
|
|
if (lseek(fd, (off_t) slot * sizeof(utmp), SEEK_SET) != -1
|
|
&& read(fd, (void *) &utmp, sizeof(utmp)) == sizeof(utmp))
|
|
{
|
|
if (utmp.ut_type != INIT_PROCESS
|
|
&& utmp.ut_type != USER_PROCESS)
|
|
log= 0;
|
|
}
|
|
close(fd);
|
|
}
|
|
if (type == LOGIN_PROCESS) log= 0; /* and don't log this one */
|
|
|
|
/* Clear the utmp record. */
|
|
memset((void *) &utmp, 0, sizeof(utmp));
|
|
|
|
/* Enter new values. */
|
|
strncpy(utmp.ut_name, user, sizeof(utmp.ut_name));
|
|
strncpy(utmp.ut_id, id, sizeof(utmp.ut_id));
|
|
strncpy(utmp.ut_line, line, sizeof(utmp.ut_line));
|
|
strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
|
|
utmp.ut_pid = pid;
|
|
utmp.ut_type = type;
|
|
utmp.ut_time = time((time_t *)0);
|
|
|
|
if (log) {
|
|
if ((fd = open(PATH_WTMP, O_WRONLY | O_APPEND)) < 0) return;
|
|
write(fd, (char *) &utmp, sizeof(struct utmp));
|
|
close(fd);
|
|
}
|
|
|
|
/* write entry to utmp */
|
|
if ((fd = open(PATH_UTMP, O_WRONLY)) < 0) return;
|
|
if (lseek(fd, (off_t) slot * sizeof(utmp), SEEK_SET) != -1)
|
|
write(fd, (char *) &utmp, sizeof(struct utmp));
|
|
close(fd);
|
|
}
|
|
|
|
void fatal(int fd, char *msg, int err)
|
|
{
|
|
int len;
|
|
char buf[80], *bp;
|
|
|
|
bp= buf;
|
|
if (!confirmed)
|
|
*bp++= '\1';
|
|
if (err)
|
|
len= sprintf(bp, "rlogind: %s: %s.\r\n", msg, strerror(err));
|
|
else
|
|
len= sprintf(bp, "rlogind: %s.\r\n", msg);
|
|
write(fd, buf, bp+len-buf);
|
|
exit(1);
|
|
}
|
|
|
|
static void setup_term(int fd)
|
|
{
|
|
char *cp, *speed;
|
|
struct termios tt;
|
|
speed_t spd;
|
|
int num;
|
|
char *check;
|
|
|
|
cp= strchr(term, '/');
|
|
if (cp)
|
|
{
|
|
tcgetattr(fd, &tt);
|
|
*cp++= '\0';
|
|
speed= cp;
|
|
cp= strchr(speed, '/');
|
|
if (cp)
|
|
*cp++= '\0';
|
|
num= strtol(speed, &check, 0);
|
|
spd= num2speed(num);
|
|
if (spd != B0 && check[0] == '\0')
|
|
{
|
|
cfsetospeed(&tt, spd);
|
|
cfsetispeed(&tt, spd);
|
|
}
|
|
tcsetattr(fd, TCSANOW, &tt);
|
|
}
|
|
env[0]= term;
|
|
env[1]= 0;
|
|
}
|
|
|
|
static speed_t num2speed(int num)
|
|
{
|
|
static struct
|
|
{
|
|
int num;
|
|
speed_t value;
|
|
} speed_table[]=
|
|
{
|
|
{ 0, B0, }, { 50, B50, }, { 75, B75, }, { 110, B110, },
|
|
{ 134, B134, }, { 150, B150, }, { 200, B200, }, { 300, B300, },
|
|
{ 600, B600, }, { 1200, B1200, }, { 1800, B1800, },
|
|
{ 2400, B2400, }, { 4800, B4800, }, { 9600, B9600, },
|
|
{ 19200, B19200, }, { 38400, B38400, },
|
|
{ -1, -1 },
|
|
};
|
|
int i;
|
|
|
|
for (i= 0; speed_table[i].num != -1; i++)
|
|
{
|
|
if (speed_table[i].num == num)
|
|
return (speed_table[i].value);
|
|
}
|
|
return B0;
|
|
}
|
|
|
|
static int do_control(char *cp, int cnt)
|
|
{
|
|
char buf[20];
|
|
struct winsize winsize;
|
|
|
|
if (cnt > sizeof(buf))
|
|
cnt= sizeof(buf);
|
|
|
|
memcpy(buf, cp, cnt);
|
|
|
|
/* Let's fetch the first 2 bytes. */
|
|
if (cnt < 2)
|
|
readall(buf+cnt, 2-cnt);
|
|
if ((unsigned char)buf[1] != 255)
|
|
return 0;
|
|
|
|
/* Let's fetch the first 4 bytes. */
|
|
if (cnt < 4)
|
|
readall(buf+cnt, 4-cnt);
|
|
if (buf[2] != 's' || buf[3] != 's')
|
|
return 0;
|
|
|
|
/* Let's fetch a winsize structure. */
|
|
if (cnt < 4 + sizeof(winsize))
|
|
readall(buf+cnt, 4 + sizeof(winsize) - cnt);
|
|
|
|
memcpy(&winsize, buf+4, sizeof(winsize));
|
|
winsize.ws_row= ntohs(winsize.ws_row);
|
|
winsize.ws_col= ntohs(winsize.ws_col);
|
|
winsize.ws_xpixel= ntohs(winsize.ws_xpixel);
|
|
winsize.ws_ypixel= ntohs(winsize.ws_ypixel);
|
|
#if DEBUG
|
|
fprintf(stderr, "setting window size to %d, %d\r\n", winsize.ws_row,
|
|
winsize.ws_col);
|
|
#endif
|
|
ioctl(1, TIOCSWINSZ, &winsize);
|
|
return 4 + sizeof(winsize);
|
|
}
|
|
|
|
static void readall(char *buf, int cnt)
|
|
{
|
|
int res;
|
|
|
|
while(cnt)
|
|
{
|
|
res= read(0, buf, cnt);
|
|
if (res <= 0)
|
|
return;
|
|
buf += cnt;
|
|
cnt -= res;
|
|
}
|
|
}
|