1 files changed, 153 insertions, 0 deletions

diff --git a/src/monkey/get_free_vt.c b/src/monkey/get_free_vt.c
new file mode 100644
index 000000000..f5c980005
--- /dev/null
+++ b/src/monkey/get_free_vt.c
@@ -0,0 +1,153 @@
+/**[txh]********************************************************************
+
+  Copyright (c) 2004 by Salvador E. Tropea.
+  Covered by the GPL license.
+
+  Module: Linux VT.
+  Comments:
+  Helper to find a free VT. That's 100% Linux specific.@p
+  The code comes from "lconsole.c" from Allegro project and was originally
+created by Marek Habersack and then modified by George Foot. I addapted it
+to my needs and changed license from giftware to GPL.@p
+  
+***************************************************************************/
+
+#define _GNU_SOURCE
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#ifdef __APPLE__
+#include <util.h>
+#endif /* __APPLE__ */
+
+#include "mi_gdb.h"
+
+#if !defined(__linux__)
+
+int mi_look_for_free_vt()
+{
+ return -1;
+}
+
+mi_aux_term *gmi_look_for_free_vt()
+{
+ return NULL;
+}
+
+#else
+
+#include <linux/vt.h>
+
+/**[txh]********************************************************************
+
+  Description:
+  Look for a free and usable Linux VT. Low level, use
+@x{gmi_look_for_free_vt}.
+  
+  Return: The VT number or <0 on error.
+  
+***************************************************************************/
+
+int mi_look_for_free_vt()
+{/* Code from Allegro. */
+ int tty, console_fd, fd;
+ unsigned short mask;
+ char tty_name[16];
+ struct vt_stat vts; 
+
+ /* Now we need to find a VT we can use.  It must be readable and
+  * writable by us, if we're not setuid root.  VT_OPENQRY itself
+  * isn't too useful because it'll only ever come up with one 
+  * suggestion, with no guarrantee that we actually have access 
+  * to it.
+  *
+  * At some stage I think this is a candidate for config
+  * file overriding, but for now we'll stat the first N consoles
+  * to see which ones we can write to (hopefully at least one!),
+  * so that we can use that one to do ioctls.  We used to use 
+  * /dev/console for that purpose but it looks like it's not 
+  * always writable by enough people.
+  *
+  * Having found and opened a writable device, we query the state
+  * of the first sixteen (fifteen really) consoles, and try 
+  * opening each unused one in turn.
+  */
+
+ console_fd=open("/dev/console",O_WRONLY);
+ if (console_fd<0)
+   {
+    int n;
+    /* Try some ttys instead... */
+    for (n=1; n<=24; n++)
+       {
+        snprintf(tty_name,sizeof(tty_name),"/dev/tty%d",n);
+        console_fd=open(tty_name,O_WRONLY);
+        if (console_fd>=0)
+           break;
+       }
+    if (n>24)
+       return -1;
+   }
+
+ /* Get the state of the console -- in particular, the free VT field */
+ if (ioctl(console_fd,VT_GETSTATE,&vts))
+    return -2;
+ close(console_fd);
+
+ /* We attempt to set our euid to 0; if we were run with euid 0 to
+  * start with, we'll be able to do this now.  Otherwise, we'll just
+  * ignore the error returned since it might not be a problem if the
+  * ttys we look at are owned by the user running the program. */
+ seteuid(0);
+
+ /* tty0 is not really a console, so start counting at 2. */
+ fd=-1;
+ for (tty=1, mask=2; mask; tty++, mask<<=1)
+     if (!(vts.v_state & mask))
+       {
+        snprintf(tty_name,sizeof(tty_name),"/dev/tty%d",tty);
+        fd=open(tty_name,O_RDWR);
+        if (fd!=-1)
+          {
+           close(fd);
+           break;
+          }
+       }
+
+ seteuid(getuid());
+
+ if (!mask)
+    return -3;
+
+ return tty;
+}
+
+/**[txh]********************************************************************
+
+  Description:
+  Look for a free and usable Linux VT to be used by the child.
+  
+  Return: A new mi_aux_term structure, you can use @x{gmi_end_aux_term} to
+release it.
+  
+***************************************************************************/
+
+mi_aux_term *gmi_look_for_free_vt()
+{
+ int vt=mi_look_for_free_vt();
+ mi_aux_term *res;
+
+ if (vt<0)
+    return NULL;
+ res=(mi_aux_term *)malloc(sizeof(mi_aux_term));
+ if (!res)
+    return NULL;
+ res->pid=-1;
+ asprintf(&res->tty,"/dev/tty%d",vt);
+ return res;
+}
+
+#endif
+