tools/xenstore: handle CLOEXEC flag for local files and pipes

For support of live update the locally used files need to have the
"close on exec" flag set. Fortunately the used Xen libraries are
already doing this, so only the logging and tdb related files and
pipes are affected. openlog() has the close on exec attribute, too.

In order to be able to keep the event channels open specify the
XENEVTCHN_NO_CLOEXEC flag when calling xenevtchn_open().

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <julien.grall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>

tools/xenstore/xenstored_control.c

@@ -41,6 +41,7 @@ Interactive commands for Xen Store Daemon.
 #define MAP_ANONYMOUS MAP_ANON
 #endif
 
+#ifndef NO_LIVE_UPDATE
 struct live_update {
 	/* For verification the correct connection is acting. */
 	struct connection *conn;
@@ -90,6 +91,7 @@ static const char *lu_begin(struct connection *conn)
 
 	return NULL;
 }
+#endif
 
 struct cmd_s {
 	char *cmd;
@@ -214,6 +216,7 @@ static int do_control_print(void *ctx, struct connection *conn,
 	return 0;
 }
 
+#ifndef NO_LIVE_UPDATE
 static const char *lu_abort(const void *ctx, struct connection *conn)
 {
 	syslog(LOG_INFO, "live-update: abort\n");
@@ -559,6 +562,7 @@ static int do_control_lu(void *ctx, struct connection *conn,
 	send_reply(conn, XS_CONTROL, resp, strlen(resp) + 1);
 	return 0;
 }
+#endif
 
 static int do_control_help(void *, struct connection *, char **, int);
 
@@ -566,6 +570,7 @@ static struct cmd_s cmds[] = {
 	{ "check", do_control_check, "" },
 	{ "log", do_control_log, "on|off" },
 
+#ifndef NO_LIVE_UPDATE
 	/*
 	 * The parameters are those of the xenstore-control utility!
 	 * Depending on environment (Mini-OS or daemon) the live-update
@@ -585,6 +590,7 @@ static struct cmd_s cmds[] = {
 	{ "live-update", do_control_lu,
 		"[-c <cmdline>] [-F] [-t <timeout>] <file>\n"
 		"    Default timeout is 60 seconds.", 4 },
+#endif
 #ifdef __MINIOS__
 	{ "memreport", do_control_memreport, "" },
 #else

tools/xenstore/xenstored_core.c

@@ -198,7 +198,8 @@ void reopen_log(void)
 	if (tracefile) {
 		close_log();
 
-		tracefd = open(tracefile, O_WRONLY|O_CREAT|O_APPEND, 0600);
+		tracefd = open(tracefile,
+			       O_WRONLY | O_CREAT | O_APPEND | O_CLOEXEC, 0600);
 
 		if (tracefd < 0)
 			perror("Could not open tracefile");
@@ -1696,7 +1697,8 @@ static void setup_structure(void)
 	if (!(tdb_flags & TDB_INTERNAL))
 		unlink(tdbname);
 
-	tdb_ctx = tdb_open_ex(tdbname, 7919, tdb_flags, O_RDWR|O_CREAT|O_EXCL,
+	tdb_ctx = tdb_open_ex(tdbname, 7919, tdb_flags,
+			      O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC,
 			      0640, &tdb_logger, NULL);
 	if (!tdb_ctx)
 		barf_perror("Could not create tdb file %s", tdbname);

tools/xenstore/xenstored_core.h

@@ -35,6 +35,14 @@
 #include "tdb.h"
 #include "hashtable.h"
 
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+/* O_CLOEXEC support is needed for Live Update in the daemon case. */
+#ifndef __MINIOS__
+#define NO_LIVE_UPDATE
+#endif
+#endif
+
 /* DEFAULT_BUFFER_SIZE should be large enough for each errno string. */
 #define DEFAULT_BUFFER_SIZE 16
 

tools/xenstore/xenstored_domain.c

@@ -743,7 +743,7 @@ void domain_init(void)
 
 	talloc_set_destructor(xgt_handle, close_xgt_handle);
 
-	xce_handle = xenevtchn_open(NULL, 0);
+	xce_handle = xenevtchn_open(NULL, XENEVTCHN_NO_CLOEXEC);
 
 	if (xce_handle == NULL)
 		barf_perror("Failed to open evtchn device");

tools/xenstore/xenstored_posix.c

@@ -90,9 +90,21 @@ void finish_daemonize(void)
 
 void init_pipe(int reopen_log_pipe[2])
 {
+	int flags;
+	unsigned int i;
+
 	if (pipe(reopen_log_pipe)) {
 		barf_perror("pipe");
 	}
+
+	for (i = 0; i < 2; i++) {
+		flags = fcntl(reopen_log_pipe[i], F_GETFD);
+		if (flags < 0)
+			barf_perror("pipe get flags");
+		flags |= FD_CLOEXEC;
+		if (fcntl(reopen_log_pipe[i],  F_SETFD, flags) < 0)
+			barf_perror("pipe set flags");
+	}
 }
 
 void unmap_xenbus(void *interface)