1 files changed, 139 insertions, 0 deletions
diff --git a/extras/ezio/vt-linux.c b/extras/ezio/vt-linux.c
new file mode 100644
index 000000000..f502c9e14
--- /dev/null
+++ b/extras/ezio/vt-linux.c
@@ -0,0 +1,139 @@
+/* Copyright (c) 2008, 2009 Nicira Networks, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * In addition, as a special exception, Nicira Networks gives permission
+ * to link the code of its release of vswitchd with the OpenSSL project's
+ * "OpenSSL" library (or with modified versions of it that use the same
+ * license as the "OpenSSL" library), and distribute the linked
+ * executables.  You must obey the GNU General Public License in all
+ * respects for all of the code used other than "OpenSSL".  If you modify
+ * this file, you may extend this exception to your version of the file,
+ * but you are not obligated to do so.  If you do not wish to do so,
+ * delete this exception statement from your version.
+ *
+ */
+
+#include <config.h>
+#include "extras/ezio/vt.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/kd.h>
+#include <linux/vt.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include "util.h"
+
+#define THIS_MODULE VLM_vt
+#include "vlog.h"
+
+static bool get_console_fd(int *fd);
+
+int
+vt_open(int open_flags)
+{
+    int console_fd, vt_fd;
+    char name[16];
+    int vt;
+
+    if (!get_console_fd(&console_fd)) {
+        return -EACCES;
+    }
+
+    /* Deallocate all unused virtual terminals, so that we don't proliferate an
+     * excess of empty ones over multiple runs. */
+    if (ioctl(console_fd, VT_DISALLOCATE, 0) < 0) {
+        VLOG_WARN("failed to deallocate empty virtual terminals: %s",
+                  strerror(errno));
+    }
+
+    /* Find a unused virtual terminal. */
+    if (ioctl(console_fd, VT_OPENQRY, &vt) < 0) {
+        int error = errno;
+        VLOG_ERR("failed to find a free virtual terminal: %s",
+                 strerror(error));
+        close(console_fd);
+        return -error;
+    }
+
+    /* Open virtual terminal. */
+    sprintf(name, "/dev/tty%d", vt);
+    vt_fd = open(name, open_flags);
+    if (vt_fd < 0) {
+        int error = errno;
+        VLOG_ERR("failed to open %s: %s", name, strerror(error));
+        close(console_fd);
+        return -error;
+    }
+
+    /* Activate virtual terminal. */
+    if (ioctl(console_fd, VT_ACTIVATE, vt) < 0
+        || ioctl(console_fd, VT_WAITACTIVE, vt) < 0) {
+        int error = errno;
+        VLOG_ERR("could not activate virtual terminal %d: %s",
+                 vt, strerror(error));
+        close(console_fd);
+        close(vt_fd);
+        return -error;
+    }
+
+    /* Success. */
+    VLOG_DBG("allocated virtual terminal %d (%s)", vt, name);
+    close(console_fd);
+    return vt_fd;
+}
+
+static bool
+is_console(int fd)
+{
+    uint8_t type = 0;
+    return !ioctl(fd, KDGKBTYPE, &type) && (type == KB_101 || type == KB_84);
+}
+
+static bool
+open_console(const char *name, int *fdp)
+{
+    *fdp = open(name, O_RDWR | O_NOCTTY);
+    if (*fdp >= 0) {
+        if (is_console(*fdp)) {
+            return true;
+        }
+        close(*fdp);
+    }
+    return false;
+}
+
+static bool
+get_console_fd(int *fdp)
+{
+    int fd;
+
+    if (open_console("/dev/tty", fdp)
+        || open_console("/dev/tty0", fdp)
+        || open_console("/dev/console", fdp)) {
+        return true;
+    }
+    for (fd = 0; fd < 3; fd++) {
+        if (is_console(fd)) {
+            *fdp = dup(fd);
+            if (*fdp >= 0) {
+                return true;
+            }
+        }
+    }
+    VLOG_ERR("unable to obtain a file descriptor for the console");
+    return false;
+}