6745433 Merge NWS consolidation into OS/Net consolidation

1 files changed, 135 insertions, 0 deletions

diff --git a/usr/src/lib/libdscfg/common/cfg_lockdlck.c b/usr/src/lib/libdscfg/common/cfg_lockdlck.c
new file mode 100644
index 0000000000..14f7cb4b1d
--- /dev/null
+++ b/usr/src/lib/libdscfg/common/cfg_lockdlck.c
@@ -0,0 +1,135 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <strings.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "cfg_impl.h"
+#include "cfg_lockd.h"
+
+
+#define	segment_off(s)	((off_t)(s) * sizeof (pid_t))
+
+static int local_lockfd;
+static int local_lockfda;
+
+void
+cfg_lfinit()
+{
+	local_lockfd = open(CFG_RDEV_LOCKFILE, O_RDWR|O_CREAT, 0644);
+	local_lockfda = open(CFG_RDEV_LOCKFILE, O_RDWR|O_APPEND, 0644);
+}
+
+int
+cfg_filelock(int segment, int flag)
+{
+	struct flock lk;
+	struct stat sb;
+	pid_t pid = 0;
+	off_t off = segment_off(segment);
+	int rc;
+
+	while (fstat(local_lockfd, &sb) == -1 && errno == EINTR)
+		;
+	if (sb.st_size < off + sizeof (pid_t)) {
+		if ((flag&O_CREAT) == 0)
+			return (CFG_LF_EOF);
+		write(local_lockfda, &pid, sizeof (pid_t));
+	}
+	bzero(&lk, sizeof (lk));
+	lk.l_type = F_WRLCK;
+	lk.l_whence = SEEK_SET;
+	lk.l_start = off;
+	lk.l_len = (off_t)sizeof (pid_t);
+
+	while ((rc = fcntl(local_lockfd, F_SETLK, &lk)) < 0 && errno == EINTR)
+		;
+	if (rc == -1 && errno == EAGAIN)
+		return (CFG_LF_AGAIN);
+
+	return (CFG_LF_OKAY);
+}
+
+
+int
+cfg_fileunlock(int segment)
+{
+	struct flock lk;
+	off_t off = segment_off(segment);
+
+	bzero(&lk, sizeof (lk));
+	lk.l_type = F_UNLCK;
+	lk.l_whence = SEEK_SET;
+	lk.l_start = off;
+	lk.l_len = (off_t)sizeof (pid_t);
+
+	while (fcntl(local_lockfd, F_SETLK, &lk) < 0 && errno == EINTR)
+		;
+	return (1);
+}
+
+void
+cfg_readpid(int segment, pid_t *pidp)
+{
+	off_t	off  = segment_off(segment);
+	lseek(local_lockfd, off, SEEK_SET);
+	read(local_lockfd, pidp, sizeof (pid_t));
+}
+
+void
+cfg_writepid(int segment, pid_t pid)
+{
+	off_t	off  = segment_off(segment);
+	lseek(local_lockfd, off, SEEK_SET);
+	write(local_lockfd, &pid, sizeof (pid_t));
+}
+
+void
+cfg_enterpid()
+{
+	int i;
+	pid_t	pid;
+
+	for (i = 0; ; i++) {
+		if (cfg_filelock(i, O_CREAT) == CFG_LF_OKAY) {
+			cfg_readpid(i, &pid);
+			if (pid != (pid_t)0) {
+				cfg_fileunlock(i);
+				continue;
+			}
+			pid = getpid();
+			cfg_writepid(i, pid);
+			break;
+		}
+	}
+}