1 files changed, 268 insertions, 0 deletions
diff --git a/usr/src/lib/libzonecfg/common/scratchops.c b/usr/src/lib/libzonecfg/common/scratchops.c
new file mode 100644
index 0000000000..04e5724660
--- /dev/null
+++ b/usr/src/lib/libzonecfg/common/scratchops.c
@@ -0,0 +1,268 @@
+/*
+ * 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 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+/*
+ * This module contains functions used for reading and writing the scratch zone
+ * translation files.  These files are used by Live Upgrade to keep track of
+ * mappings between actual kernel zone names and the zones in an alternate boot
+ * environment.
+ *
+ * The functions are MT-safe.
+ *
+ * The file format looks like this:
+ *
+ *	<zonename>	<kernel-zonename>	<alt-root>
+ *
+ * The expected usage model is:
+ *
+ *	fp = zonecfg_open_scratch("", B_TRUE);
+ *	zonecfg_lock_scratch(fp);
+ *	if (zonecfg_find_scratch(fp, zonename, altroot, NULL, 0) == 0) {
+ *		handle error; zone already mounted
+ *	}
+ *	mount zone here
+ *	zonecfg_add_scratch(fp, zonename, kernname, altroot);
+ *	zonecfg_close_scratch(fp);
+ *	fp = zonecfg_open_scratch(zoneroot, B_TRUE);
+ *	ftruncate(fileno(fp), 0);
+ *	zonecfg_add_scratch(fp, zonename, kernname, "/");
+ *	zonecfg_close_scratch(fp);
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <libzonecfg.h>
+
+#define	PATH_MAPFILE	"tmp/.alt.lu-zone-map"
+
+static int
+lock_op(int fd, int type)
+{
+	struct flock lock;
+
+	lock.l_type = type;
+	lock.l_whence = SEEK_SET;
+	lock.l_start = 0;
+	lock.l_len = 0;
+
+	return (fcntl(fd, F_SETLKW, &lock));
+}
+
+FILE *
+zonecfg_open_scratch(const char *rootpath, boolean_t createfile)
+{
+	mode_t oldmask = umask(0);
+	struct stat lbuf, fbuf;
+	int fd, flags;
+	FILE *fp;
+	char mapfile[MAXPATHLEN];
+
+	(void) snprintf(mapfile, sizeof (mapfile), "%s/" PATH_MAPFILE,
+	    rootpath);
+
+	flags = O_RDWR | O_NOFOLLOW | O_NOLINKS;
+	if (createfile)
+		flags |= O_EXCL | O_CREAT;
+	if ((fd = open(mapfile, flags, 0644)) == -1) {
+		if (!createfile) {
+			errno = ENOENT;
+			goto failure;
+		}
+		if (lstat(mapfile, &lbuf) == -1)
+			goto failure;
+		if (!S_ISREG(lbuf.st_mode) || lbuf.st_nlink != 1 ||
+		    lbuf.st_uid != 0) {
+			errno = EINVAL;
+			goto failure;
+		}
+		fd = open(mapfile, O_RDWR);
+		if (fd == -1)
+			goto failure;
+		if (fstat(fd, &fbuf) == -1)
+			goto failure;
+		if (lbuf.st_ino != fbuf.st_ino || lbuf.st_dev != fbuf.st_dev) {
+			errno = EINVAL;
+			goto failure;
+		}
+	}
+	if (lock_op(fd, F_RDLCK) == -1)
+		goto failure;
+	(void) umask(oldmask);
+	if ((fp = fdopen(fd, "r+")) == NULL)
+		(void) close(fd);
+	return (fp);
+
+failure:
+	if (fd != -1)
+		(void) close(fd);
+	(void) umask(oldmask);
+	return (NULL);
+}
+
+int
+zonecfg_lock_scratch(FILE *fp)
+{
+	if (fflush(fp) != 0)
+		return (-1);
+	return (lock_op(fileno(fp), F_WRLCK));
+}
+
+void
+zonecfg_close_scratch(FILE *fp)
+{
+	(void) fclose(fp);
+}
+
+int
+zonecfg_get_scratch(FILE *fp, char *zonename, size_t namelen, char *kernname,
+    size_t kernlen, char *altroot, size_t altlen)
+{
+	char line[2 * ZONENAME_MAX + MAXPATHLEN + 2];
+	char *cp, *cp2;
+
+	/* We always hold at least a read lock on the file */
+	for (;;) {
+		if (fgets(line, sizeof (line), fp) == NULL)
+			return (-1);
+		if ((cp = strchr(line, '\n')) == NULL)
+			return (-1);
+		*cp = '\0';
+		if ((cp = strchr(line, ' ')) == NULL)
+			cp = line + strlen(line);
+		else
+			*cp++ = '\0';
+		if (zonename != NULL &&
+		    strlcpy(zonename, line, namelen) >= namelen)
+			continue;
+		if ((cp2 = strchr(cp, ' ')) == NULL)
+			cp2 = cp + strlen(cp);
+		else
+			*cp2++ = '\0';
+		if (kernname != NULL &&
+		    strlcpy(kernname, cp, kernlen) >= kernlen)
+			continue;
+		if (altroot != NULL && strlcpy(altroot, cp2, altlen) >= altlen)
+			continue;
+		break;
+	}
+	return (0);
+}
+
+int
+zonecfg_find_scratch(FILE *fp, const char *zonename, const char *altroot,
+    char *kernzone, size_t kernlen)
+{
+	char zone[ZONENAME_MAX];
+	char aroot[MAXPATHLEN];
+
+	rewind(fp);
+	while (zonecfg_get_scratch(fp, zone, sizeof (zone), kernzone, kernlen,
+	    aroot, sizeof (aroot)) == 0) {
+		if (strcmp(zone, zonename) == 0 && strcmp(altroot, aroot) == 0)
+			return (0);
+	}
+	return (-1);
+}
+
+int
+zonecfg_reverse_scratch(FILE *fp, const char *kernzone, char *zonename,
+    size_t namelen, char *altroot, size_t altlen)
+{
+	char kzone[ZONENAME_MAX];
+
+	rewind(fp);
+	while (zonecfg_get_scratch(fp, zonename, namelen, kzone,
+	    sizeof (kzone), altroot, altlen) == 0) {
+		if (strcmp(kzone, kernzone) == 0)
+			return (0);
+	}
+	return (-1);
+}
+
+int
+zonecfg_add_scratch(FILE *fp, const char *zonename, const char *kernzone,
+    const char *altroot)
+{
+	if (fseek(fp, 0, SEEK_END) == -1)
+		return (-1);
+	if (fprintf(fp, "%s %s %s\n", zonename, kernzone, altroot) == EOF)
+		return (-1);
+	if (fflush(fp) != 0)
+		return (-1);
+	return (0);
+}
+
+int
+zonecfg_delete_scratch(FILE *fp, const char *kernzone)
+{
+	char zone[ZONENAME_MAX];
+	char kzone[ZONENAME_MAX];
+	char aroot[MAXPATHLEN];
+	long roffs, woffs;
+
+	/*
+	 * The implementation here is intentionally quite simple.  We could
+	 * allocate a buffer that's big enough to hold the data up to
+	 * stat.st_size and then write back out the part we need to, but there
+	 * seems to be little point.
+	 */
+	rewind(fp);
+	roffs = 0;
+	do {
+		woffs = roffs;
+		if (zonecfg_get_scratch(fp, NULL, 0, kzone, sizeof (kzone),
+		    NULL, 0) != 0)
+			return (-1);
+		roffs = ftell(fp);
+	} while (strcmp(kzone, kernzone) != 0);
+	while (zonecfg_get_scratch(fp, zone, sizeof (zone), kzone,
+	    sizeof (kzone), aroot, sizeof aroot) == 0) {
+		roffs = ftell(fp);
+		if (fseek(fp, woffs, SEEK_SET) == -1)
+			break;
+		if (fprintf(fp, "%s %s %s\n", zone, kzone, aroot) == EOF)
+			break;
+		woffs = ftell(fp);
+		if (fseek(fp, roffs, SEEK_SET) == -1)
+			break;
+	}
+	(void) ftruncate(fileno(fp), woffs);
+	return (0);
+}
+
+boolean_t
+zonecfg_is_scratch(const char *kernzone)
+{
+	return (strncmp(kernzone, "SUNWlu", 6) == 0);
+}