84 lines
1.8 KiB
C
84 lines
1.8 KiB
C
/*
|
|
* openpty() tries to open a pty; applications won't have to
|
|
* duplicate this code all the time (or change it if the system
|
|
* pty interface changes).
|
|
*
|
|
* First version by Ben Gras <beng@few.vu.nl>,
|
|
* Initially heavily based on telnetd/pty.c
|
|
* by Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>.
|
|
*
|
|
*/
|
|
#include <libutil.h>
|
|
#include <termios.h>
|
|
#include <fcntl.h>
|
|
#include <grp.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/ioc_tty.h>
|
|
|
|
#define DEV_DIR "/dev"
|
|
|
|
/*
|
|
* Allocate a PTY, by trying to open one repeatedly.
|
|
*/
|
|
int openpty(int *amaster, int *aslave, char *name,
|
|
struct termios *termp, struct winsize *winp)
|
|
{
|
|
char buff[128], temp[128];
|
|
register int i, j;
|
|
int pty_fd = -1, gr;
|
|
static char tty_name[128];
|
|
struct group *ttygroup;
|
|
gid_t tty_gid = 0;
|
|
|
|
if(!amaster || !aslave) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
for(i = 'p'; i < 'w'; i++) {
|
|
j = 0;
|
|
do {
|
|
sprintf(buff, "%s/pty%c%c",
|
|
DEV_DIR, i, (j < 10) ? j + '0' : j + 'a' - 10);
|
|
|
|
if((*amaster = open(buff, O_RDWR)) >= 0) {
|
|
sprintf(tty_name, "%s/tty%c%c", DEV_DIR,
|
|
i, (j < 10) ? j + '0' : j + 'a' - 10);
|
|
if((*aslave = open(tty_name, O_RDWR)) >= 0) {
|
|
break;
|
|
}
|
|
close(*amaster);
|
|
}
|
|
|
|
j++;
|
|
if (j == 16) break;
|
|
} while(1);
|
|
|
|
/* Did we find one? */
|
|
if (j < 16) break;
|
|
}
|
|
if (*amaster < 0) { errno = ENOENT; return(-1); }
|
|
|
|
setgrent();
|
|
ttygroup = getgrnam("tty");
|
|
endgrent();
|
|
if(ttygroup) tty_gid = ttygroup->gr_gid;
|
|
|
|
if(name) strcpy(name, tty_name);
|
|
|
|
/* Ignore errors on these. */
|
|
chown(tty_name, getuid(), tty_gid);
|
|
chmod(tty_name, 0620); /* -rw--w---- */
|
|
if(termp) tcsetattr(*aslave, TCSAFLUSH, termp);
|
|
if(winp) ioctl(*aslave, TIOCSWINSZ, winp);
|
|
|
|
return(0);
|
|
}
|
|
|