Watchdog timers for domains

Each domain is allowed to set, reset and disable its timers; when any
timer runs out the domain is killed.

Patch from Christian Limpach <Christian.Limpach@citrix.com>
Signed-off-by: Tim Deegan <Tim.Deegan@citrix.com>

1 files changed, 96 insertions, 0 deletions

diff --git a/tools/misc/xenwatchdogd.c b/tools/misc/xenwatchdogd.c
new file mode 100644
index 0000000000..aa96834e5f
--- /dev/null
+++ b/tools/misc/xenwatchdogd.c
@@ -0,0 +1,96 @@
+
+#include <err.h>
+#include <limits.h>
+#include "xenctrl.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+
+xc_interface *h;
+int id = 0;
+
+void daemonize(void)
+{
+    switch (fork()) {
+    case -1:
+	err(1, "fork");
+    case 0:
+	break;
+    default:
+	exit(0);
+    }
+    umask(0);
+    if (setsid() < 0)
+	err(1, "setsid");
+    if (chdir("/") < 0)
+	err(1, "chdir /");
+    freopen("/dev/null", "r", stdin);
+    freopen("/dev/null", "w", stdout);
+    freopen("/dev/null", "w", stderr);
+}
+
+void catch_exit(int sig)
+{
+    if (id)
+        xc_watchdog(h, id, 300);
+    exit(0);
+}
+
+void catch_usr1(int sig)
+{
+    if (id)
+        xc_watchdog(h, id, 0);
+    exit(0);
+}
+
+int main(int argc, char **argv)
+{
+    int t, s;
+    int ret;
+
+    if (argc < 2)
+	errx(1, "usage: %s <timeout> <sleep>", argv[0]);
+
+    daemonize();
+
+    h = xc_interface_open(NULL, NULL, 0);
+    if (h == NULL)
+	err(1, "xc_interface_open");
+
+    t = strtoul(argv[1], NULL, 0);
+    if (t == ULONG_MAX)
+	err(1, "strtoul");
+
+    s = t / 2;
+    if (argc == 3) {
+	s = strtoul(argv[2], NULL, 0);
+	if (s == ULONG_MAX)
+	    err(1, "strtoul");
+    }
+
+    if (signal(SIGHUP, &catch_exit) == SIG_ERR)
+	err(1, "signal");
+    if (signal(SIGINT, &catch_exit) == SIG_ERR)
+	err(1, "signal");
+    if (signal(SIGQUIT, &catch_exit) == SIG_ERR)
+	err(1, "signal");
+    if (signal(SIGTERM, &catch_exit) == SIG_ERR)
+	err(1, "signal");
+    if (signal(SIGUSR1, &catch_usr1) == SIG_ERR)
+	err(1, "signal");
+
+    id = xc_watchdog(h, 0, t);
+    if (id <= 0)
+        err(1, "xc_watchdog setup");
+
+    for (;;) {
+        sleep(s);
+        ret = xc_watchdog(h, id, t);
+        if (ret != 0)
+            err(1, "xc_watchdog");
+    }
+}