add stuff to use /dev/ptmx etc.

diff --git a/pppd/sys-linux.c b/pppd/sys-linux.c
index 436a5f1af66eab217a846c70e7b0e04e44f8b653..d494c847e4e689eecf32fadb6093e03c1e24804b 100644 (file)
--- a/pppd/sys-linux.c
+++ b/pppd/sys-linux.c
@@ -2117,7 +2117,7 @@ int cifaddr (int unit, u_int32_t our_adr, u_int32_t his_adr)
 
 /*
  * get_pty - get a pty master/slave pair and chown the slave side
- * to the uid given.  Assumes slave_name points to >= 12 bytes of space.
+ * to the uid given.  Assumes slave_name points to >= 16 bytes of space.
  */
 int
 get_pty(master_fdp, slave_fdp, slave_name, uid)
@@ -2126,31 +2126,56 @@ get_pty(master_fdp, slave_fdp, slave_name, uid)
     char *slave_name;
     int uid;
 {
-    int i, mfd, sfd;
-    char pty_name[12];
+    int i, mfd, sfd = -1;
+    char pty_name[16];
     struct termios tios;
 
-    sfd = -1;
-    for (i = 0; i < 64; ++i) {
-       slprintf(pty_name, sizeof(pty_name), "/dev/pty%c%x",
-                'p' + i / 16, i % 16);
-       mfd = open(pty_name, O_RDWR, 0);
-       if (mfd >= 0) {
-           pty_name[5] = 't';
-           sfd = open(pty_name, O_RDWR | O_NOCTTY, 0);
-           if (sfd >= 0)
-               break;
-           close(mfd);
+#ifdef TIOCGPTN
+    /*
+     * Try the unix98 way first.
+     */
+    mfd = open("/dev/ptmx", O_RDWR);
+    if (mfd >= 0) {
+       int ptn;
+       if (ioctl(mfd, TIOCGPTN, &ptn) >= 0) {
+           slprintf(pty_name, sizeof(pty_name), "/dev/pts/%d", ptn);
+           chmod(pty_name, S_IRUSR | S_IWUSR);
+#ifdef TIOCSPTLCK
+           ptn = 0;
+           if (ioctl(mfd, TIOCSPTLCK, &ptn) < 0)
+               warn("Couldn't unlock pty slave %s: %m", pty_name);
+#endif
+           if ((sfd = open(pty_name, O_RDWR)) < 0)
+               warn("Couldn't open pty slave %s: %m", pty_name);
        }
     }
+#endif /* TIOCGPTN */
+
+    if (sfd < 0) {
+       /* the old way - scan through the pty name space */
+       for (i = 0; i < 64; ++i) {
+           slprintf(pty_name, sizeof(pty_name), "/dev/pty%c%x",
+                    'p' + i / 16, i % 16);
+           mfd = open(pty_name, O_RDWR, 0);
+           if (mfd >= 0) {
+               pty_name[5] = 't';
+               sfd = open(pty_name, O_RDWR | O_NOCTTY, 0);
+               if (sfd >= 0) {
+                   fchown(sfd, uid, -1);
+                   fchmod(sfd, S_IRUSR | S_IWUSR);
+                   break;
+               }
+               close(mfd);
+           }
+       }
+    }
+
     if (sfd < 0)
        return 0;
 
-    strlcpy(slave_name, pty_name, 12);
+    strlcpy(slave_name, pty_name, 16);
     *master_fdp = mfd;
     *slave_fdp = sfd;
-    fchown(sfd, uid, -1);
-    fchmod(sfd, S_IRUSR | S_IWUSR);
     if (tcgetattr(sfd, &tios) == 0) {
        tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB);
        tios.c_cflag |= CS8 | CREAD;