wdctl: add watchdog status tool

For: util-linux

This patch adds a tiny tool "wdctl" which may be used to query the
status of Linux watchdog devices (/dev/watchdog).

This will simply query all fields that may be queried from the
device and print them nicely formatted.

Signed-off-by: Lennart Poettering <lennart@poettering.net>

1 files changed, 180 insertions, 0 deletions

diff --git a/sys-utils/wdctl.c b/sys-utils/wdctl.c
new file mode 100644
index 000000000..179aff207
--- /dev/null
+++ b/sys-utils/wdctl.c
@@ -0,0 +1,180 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: t -*-*/
+
+/*
+ * wdctl(8) - show hardware watchdog status
+ *
+ * Copyright (C) 2012 Lennart Poettering
+ *
+ * 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 2, 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/watchdog.h>
+#include <sys/ioctl.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "nls.h"
+#include "c.h"
+
+static const struct {
+	uint32_t flag;
+	const char *name;
+} flag_names[] = {
+	{ WDIOF_OVERHEAT,      N_("OVERHEAT: Reset due to CPU overheat") },
+	{ WDIOF_FANFAULT,      N_("FANFAULT: Fan failed") },
+	{ WDIOF_EXTERN1,       N_("EXTERN1: External relay 1") },
+	{ WDIOF_EXTERN2,       N_("EXTERN2: External relay 2") },
+	{ WDIOF_POWERUNDER,    N_("POWERUNDER: Power bad/power fault") },
+	{ WDIOF_CARDRESET,     N_("CARDRESET: Card previously reset the CPU") },
+	{ WDIOF_POWEROVER,     N_("POWEROVER: Power over voltage") },
+	{ WDIOF_SETTIMEOUT,    N_("SETTIMEOUT: Set timeout (in seconds)") },
+	{ WDIOF_MAGICCLOSE,    N_("MAGICCLOSE: Supports magic close char") },
+	{ WDIOF_PRETIMEOUT,    N_("PRETIMEOUT: Pretimeout (in seconds)") },
+	{ WDIOF_KEEPALIVEPING, N_("KEEPALIVEPING: Keep alive ping reply") }
+};
+
+static void usage(int status)
+{
+	FILE *out = status == EXIT_SUCCESS ? stdout : stderr;
+
+	fputs(USAGE_HEADER, out);
+	fprintf(out,
+	      _(" %s [options]\n"), program_invocation_short_name);
+
+	fputs(USAGE_OPTIONS, out);
+	fputs(_(" -d, --device=	 device to use (/dev/watchdog)\n"), out);
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(USAGE_HELP, out);
+	fputs(USAGE_VERSION, out);
+	fprintf(out, USAGE_MAN_TAIL("wdctl(1)"));
+
+	exit(status);
+}
+
+static void print_options(uint32_t options)
+{
+	unsigned i;
+
+	if (options == 0) {
+		puts(_("\tNo flags set."));
+		return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(flag_names); i++) {
+		if (options & flag_names[i].flag)
+			printf("\t%s\n", _(flag_names[i].name));
+		options &= ~flag_names[i].flag;
+	}
+
+	if (options)
+		printf(_("\tUnknown flags 0x%x\n"), options);
+}
+
+int main(int argc, char *argv[])
+{
+	static const struct option longopts[] = {
+		{ "help",    no_argument,       0, 'h' },
+		{ "version", no_argument,       0, 'V'},
+		{ "device",  required_argument, 0, 'd' },
+		{ NULL, 0, 0, 0 }
+	};
+
+	int c, status, sec, fd;
+	const char *device = "/dev/watchdog";
+	struct watchdog_info ident;
+
+	setlocale(LC_MESSAGES, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	while((c = getopt_long(argc, argv, "hVd:", longopts, NULL)) != -1) {
+
+		switch(c) {
+		case 'h':
+			usage(EXIT_SUCCESS);
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			return EXIT_SUCCESS;
+		case 'd':
+			device = optarg;
+			break;
+		default:
+			usage(EXIT_FAILURE);
+		}
+	}
+
+	if (optind < argc)
+		usage(EXIT_FAILURE);
+
+	fd = open(device, O_WRONLY|O_CLOEXEC);
+	if (fd < 0) {
+		if (errno == EBUSY)
+			errx(EXIT_FAILURE, _("Watchdog already in use, terminating."));
+
+		err(EXIT_FAILURE, _("Failed to open watchdog device"));
+	}
+
+        if (ioctl(fd, WDIOC_GETSUPPORT, &ident) >= 0) {
+                printf(_("Identity:\n\t%s\n"
+			 "Firmware version:\n\t%x\n"
+			 "Supported options:\n"),
+			 ident.identity,
+			 ident.firmware_version);
+		print_options(ident.options);
+	}
+
+	if (ioctl(fd, WDIOC_GETSTATUS, &status) >= 0) {
+		puts(_("Status:"));
+		print_options((uint32_t) status);
+	}
+
+	if (ioctl(fd, WDIOC_GETBOOTSTATUS, &status) >= 0) {
+		puts(_("Boot status:"));
+		print_options((uint32_t) status);
+	}
+
+	if (ioctl(fd, WDIOC_GETTIMEOUT, &sec) >= 0)
+		printf(_("Timeout:\n\t%is\n"), sec);
+
+	if (ioctl(fd, WDIOC_GETPRETIMEOUT, &sec) >= 0)
+		printf(_("Pre-Timeout:\n\t%is\n"), sec);
+
+	if (ioctl(fd, WDIOC_GETTIMELEFT, &sec) >= 0)
+		printf(_("Time Left:\n\t%is\n"), sec);
+
+	for (;;) {
+		/* We just opened this to query the state, not to arm
+		 * it hence use the magic close character */
+
+		static const char v = 'V';
+
+		if (write(fd, &v, 1) >= 0)
+			break;
+
+		if (errno != EINTR) {
+			warn(_("Failed to disarm watchdog"));
+			break;
+		}
+
+		/* Let's try hard, since if we don't get this right
+		 * the machine might end up rebooting. */
+	}
+
+	close(fd);
+
+	return 0;
+}