PSARC/2009/516 Timezone cache renewal

6751272 RFE: Solaris timezone patches should not require reboot

2 files changed, 463 insertions, 0 deletions

diff --git a/usr/src/cmd/tzreload/Makefile b/usr/src/cmd/tzreload/Makefile
new file mode 100644
index 0000000000..21325d3937
--- /dev/null
+++ b/usr/src/cmd/tzreload/Makefile
@@ -0,0 +1,43 @@
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+# Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+PROG=tzreload
+
+include ../Makefile.cmd
+
+CPPFLAGS += -I../cron
+
+.KEEP_STATE:
+
+all: $(PROG) 
+
+install: all $(ROOTSBINPROG)
+	$(RM) $(ROOTUSRSBIN)/$(PROG)
+	$(SYMLINK) ../../sbin/$(PROG) $(ROOTUSRSBIN)/$(PROG)
+
+clean:
+
+lint:	lint_PROG
+
+include ../Makefile.targ
diff --git a/usr/src/cmd/tzreload/tzreload.c b/usr/src/cmd/tzreload/tzreload.c
new file mode 100644
index 0000000000..30d4a7600a
--- /dev/null
+++ b/usr/src/cmd/tzreload/tzreload.c
@@ -0,0 +1,420 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
+/*	All Rights Reserved	*/
+
+#include <atomic.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <locale.h>
+#include <libintl.h>
+#include <zone.h>
+#include <libzonecfg.h>
+#include <sys/brand.h>
+#include <dlfcn.h>
+
+#define	TZSYNC_FILE	"/var/run/tzsync"
+
+static void	init_file(void);
+static void	doit(const char *zname, const char *zroot, int get);
+static void	counter_get(const char *zname, int fd);
+static void	counter_set(int fd);
+static void	walk_zones(int get);
+static void	send_cron_msg(const char *zname, const char *zroot);
+
+/*
+ * There are undocumeted command line options:
+ * -l	list the value of semaphore.
+ * -I	initialize the semaphore file (ie /var/run/tzsync)
+ */
+
+int
+main(int argc, char **argv)
+{
+	int	arg;
+	int	all = 0, get = 0, init = 0;
+
+	(void) setlocale(LC_ALL, "");
+	(void) textdomain(TEXT_DOMAIN);
+
+	while ((arg = getopt(argc, argv, "alI")) != EOF) {
+		switch (arg) {
+		case 'a':
+			all = 1;
+			break;
+		case 'l':
+			get = 1;
+			break;
+		case 'I':
+			init = 1;
+			break;
+		default:
+			(void) fprintf(stderr,
+			    gettext("Usage: tzreload [-a]\n"));
+			exit(1);
+		}
+	}
+
+	if (init) {
+		init_file();
+		return (0);
+	}
+
+	if (all)
+		walk_zones(get);
+	else
+		doit(NULL, "", get);
+
+	return (0);
+}
+
+/*
+ * Create /var/run/tzsync atomically.
+ *
+ * While creating the /var/run/tzsync initially, there is a timing window
+ * that the file is created but no disk block is allocated (empty file).
+ * If apps mmap'ed the file at the very moment, it succeeds but accessing
+ * the memory page causes a segfault since disk block isn't yet allocated.
+ * To avoid this situation, we create a temp file which has pagesize block
+ * assigned, and then rename it to tzsync.
+ */
+static void
+init_file(void)
+{
+	char	path[sizeof (TZSYNC_FILE) + 16];
+	char	*buf;
+	int	fd, pgsz;
+	struct stat st;
+
+	/* We don't allow to re-create the file */
+	if (stat(TZSYNC_FILE, &st) == 0) {
+		(void) fprintf(stderr, gettext("%s already exists.\n"),
+		    TZSYNC_FILE);
+		exit(1);
+	}
+
+	pgsz = sysconf(_SC_PAGESIZE);
+
+	(void) strcpy(path, TZSYNC_FILE "XXXXXX");
+	if ((fd = mkstemp(path)) == -1) {
+		(void) fprintf(stderr,
+		    gettext("failed to create a temporary file.\n"));
+		exit(1);
+	}
+
+	if ((buf = calloc(1, pgsz)) == NULL) {
+		(void) fprintf(stderr, gettext("Insufficient memory.\n"));
+errout:
+		(void) close(fd);
+		(void) unlink(path);
+		exit(1);
+	}
+
+	if (write(fd, buf, pgsz) != pgsz) {
+		(void) fprintf(stderr,
+		    gettext("failed to create tzsync file, %s\n"),
+		    strerror(errno));
+		goto errout;
+	}
+	(void) close(fd);
+
+	/* link it */
+	if (link(path, TZSYNC_FILE) != 0) {
+		if (errno == EEXIST) {
+			(void) fprintf(stderr, gettext("%s already exists.\n"),
+			    TZSYNC_FILE);
+		} else {
+			(void) fprintf(stderr, gettext("failed to create %s\n"),
+			    TZSYNC_FILE);
+		}
+		(void) unlink(path);
+		exit(1);
+	}
+	(void) unlink(path);
+
+	/*
+	 * Unplivileged apps may fail to open the file until the chmod
+	 * below succeeds. However, it's okay as long as open() fails;
+	 * ctime() won't cache zoneinfo until file is opened and mmap'd.
+	 */
+
+	/* /var/run/tzsync has been made. Adjust permission */
+	if (chmod(TZSYNC_FILE, 0644) != 0) {
+		(void) fprintf(stderr,
+		    gettext("failed to change permission of %s\n"),
+		    TZSYNC_FILE);
+		(void) unlink(TZSYNC_FILE);
+		exit(1);
+	}
+}
+
+/*
+ * Open the /var/run/tzsync, then set or get the semaphore.
+ *
+ * zname	name of zone (NULL if no need to consider zones)
+ * zroot	zone's root path
+ * get		get/set semaphore
+ */
+static void
+doit(const char *zname, const char *zroot, int get)
+{
+	int	fd;
+	char	file[PATH_MAX + 1];
+
+	if (strlcpy(file, zroot, sizeof (file)) >= sizeof (file) ||
+	    strlcat(file, TZSYNC_FILE, sizeof (file)) >= sizeof (file)) {
+		(void) fprintf(stderr, gettext("zonepath too long\n"));
+		exit(1);
+	}
+
+	if ((fd = open(file, get ? O_RDONLY : O_RDWR)) < 0) {
+		(void) fprintf(stderr,
+		    gettext("Can't open file %s, %s\n"),
+		    file, strerror(errno));
+		exit(1);
+	}
+
+	if (get) {
+		counter_get(zname, fd);
+	} else {
+		counter_set(fd);
+		/* let cron reschedule events */
+		send_cron_msg(zname, zroot);
+	}
+
+	(void) close(fd);
+}
+
+/*
+ * Get semaphore value and print.
+ */
+static void
+counter_get(const char *zname, int fd)
+{
+	uint32_t counter;
+	caddr_t	addr;
+
+	addr = mmap(NULL, sizeof (uint32_t), PROT_READ, MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED) {
+		(void) fprintf(stderr,
+		    gettext("Error mapping semaphore: %s\n"),
+		    strerror(errno));
+		exit(1);
+	}
+	counter = *(uint32_t *)(uintptr_t)addr;
+
+	(void) munmap(addr, sizeof (uint32_t));
+
+	if (zname == NULL)
+		(void) printf("%u\n", counter);
+	else
+		(void) printf("%-20s %u\n", zname, counter);
+
+}
+
+/*
+ * Increment semaphore value.
+ */
+static void
+counter_set(int fd)
+{
+	caddr_t	addr;
+
+	addr = mmap(NULL, sizeof (uint32_t), PROT_READ|PROT_WRITE,
+	    MAP_SHARED, fd, 0);
+	if (addr == MAP_FAILED) {
+		(void) fprintf(stderr,
+		    gettext("Error mapping semaphore: %s\n"),
+		    strerror(errno));
+		exit(1);
+	}
+
+	/*LINTED*/
+	atomic_add_32((uint32_t *)addr, 1);
+
+	(void) munmap(addr, sizeof (uint32_t));
+}
+
+/*
+ * Walk through running zones and call doit() for each zones.
+ *
+ * Note: we call zone_get_rootpath() indirectly using dlopen().
+ * This is because tzreload resides under /sbin and needs to run
+ * without /usr (ie /usr/lib/libzonecfg.so.1). The reason tzreload
+ * being in /sbin is that tzreload -I may be called to create
+ * /var/run/tzsync before /usr is mounted. To do that zone_get_rootpath()
+ * isn't necessary. Therefore, libzonecfg is dlopen'd when required
+ * rather than having static linkage to it which would make tzreload
+ * unable to run without /usr.
+ */
+static void
+walk_zones(int get)
+{
+	zoneid_t *zids;
+	uint_t	ui, nzents, onzents;
+	char	zroot[PATH_MAX + 1];
+	char	zname[ZONENAME_MAX];
+	char	zbrand[MAXNAMELEN];
+	static int (*get_zroot)(char *, char *, size_t);
+
+	if (getzoneid() != GLOBAL_ZONEID) {
+		(void) fprintf(stderr, gettext("not in the global zone.\n"));
+		exit(1);
+	}
+
+	if (get_zroot == NULL) {
+		void	*hdl;
+
+		if ((hdl = dlopen("libzonecfg.so.1", RTLD_NOW)) == NULL) {
+			(void) fprintf(stderr,
+			    gettext("unable to get zone configuration.\n"));
+			exit(1);
+		}
+		get_zroot = (int (*)(char *, char *, size_t))
+		    dlsym(hdl, "zone_get_rootpath");
+		if (get_zroot == NULL) {
+			(void) fprintf(stderr,
+			    gettext("unable to get zone configuration.\n"));
+			exit(1);
+		}
+	}
+
+	nzents = 0;
+	if (zone_list(NULL, &nzents) != 0) {
+		(void) fprintf(stderr,
+		    gettext("failed to get zoneid list\n"));
+		exit(1);
+	}
+
+again:
+	if (nzents == 0)
+		return;
+
+	if ((zids = malloc(nzents * sizeof (zoneid_t))) == NULL) {
+		(void) fprintf(stderr, gettext("Insufficient memory.\n"));
+		exit(1);
+	}
+
+	onzents = nzents;
+	if (zone_list(zids, &nzents) != 0) {
+		(void) fprintf(stderr,
+		    gettext("failed to get zoneid list\n"));
+		exit(1);
+	}
+
+	if (nzents != onzents) {
+		/* zone increased while doing zone_list() */
+		free(zids);
+		goto again;
+	}
+
+	for (ui = 0; ui < nzents; ui++) {
+		if (zone_getattr(zids[ui], ZONE_ATTR_BRAND, zbrand,
+		    sizeof (zbrand)) < 0) {
+			(void) fprintf(stderr,
+			    gettext("failed to get zone attribute\n"));
+			exit(1);
+		}
+		/* We only take care of native zones */
+		if (strcmp(zbrand, NATIVE_BRAND_NAME) != 0)
+			continue;
+		if (getzonenamebyid(zids[ui], zname, sizeof (zname)) < 0) {
+			(void) fprintf(stderr,
+			    gettext("failed to get zone name\n"));
+			exit(1);
+		}
+
+		if (zids[ui] == GLOBAL_ZONEID) {
+			zroot[0] = '\0';
+		} else {
+			if ((*get_zroot)(zname, zroot,
+			    sizeof (zroot)) != Z_OK) {
+				(void) fprintf(stderr,
+				    gettext("failed to get zone's root\n"));
+				exit(1);
+			}
+		}
+		doit(zname, zroot, get);
+	}
+}
+
+#include "cron.h"
+
+/*
+ * Send REFRESH event to cron.
+ */
+static void
+send_cron_msg(const char *zname, const char *zroot)
+{
+	struct message msg;
+	int	msgfd;
+	char	fifo[PATH_MAX + 1];
+
+	if (strlcpy(fifo, zroot, sizeof (fifo)) >= sizeof (fifo) ||
+	    strlcat(fifo, FIFO, sizeof (fifo)) >= sizeof (fifo)) {
+		(void) fprintf(stderr, gettext("zonepath too long\n"));
+		exit(1);
+	}
+
+	(void) memset(&msg, 0, sizeof (msg));
+	msg.etype = REFRESH;
+
+	if ((msgfd = open(fifo, O_WRONLY|O_NDELAY)) < 0) {
+		if (errno == ENXIO || errno == ENOENT) {
+			if (zname != NULL) {
+				(void) fprintf(stderr, gettext(
+				    "cron isn't running in %s zone.\n"), zname);
+			} else {
+				(void) fprintf(stderr,
+				    gettext("cron isn't running.\n"));
+			}
+		} else {
+			if (zname != NULL) {
+				(void) fprintf(stderr, gettext(
+				    "failed to send message to cron "
+				    "in %s zone.\n"), zname);
+			} else {
+				(void) fprintf(stderr, gettext(
+				    "failed to send message to cron.\n"));
+			}
+		}
+		return;
+	}
+
+	if (write(msgfd, &msg, sizeof (msg)) != sizeof (msg)) {
+		(void) fprintf(stderr, gettext("failed to send message.\n"));
+	}
+
+	(void) close(msgfd);
+}