1 files changed, 287 insertions, 0 deletions
diff --git a/lib/support/plausible.c b/lib/support/plausible.c
new file mode 100644
index 0000000..65a6b2e
--- /dev/null
+++ b/lib/support/plausible.c
@@ -0,0 +1,287 @@
+/*
+ * plausible.c --- Figure out if a pathname is ext* or something else.
+ *
+ * Copyright 2014, Oracle, Inc.
+ *
+ * Some parts are:
+ * Copyright 1995, 1996, 1997, 1998, 1999, 2000 by Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#ifndef _LARGEFILE_SOURCE
+#define _LARGEFILE_SOURCE
+#endif
+#ifndef _LARGEFILE64_SOURCE
+#define _LARGEFILE64_SOURCE
+#endif
+
+#include "config.h"
+#include <fcntl.h>
+#include <time.h>
+#include <sys/types.h>
+#ifdef HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_MAGIC_H
+#include <magic.h>
+#endif
+#include "plausible.h"
+#include "ext2fs/ext2fs.h"
+#include "nls-enable.h"
+#include "blkid/blkid.h"
+
+#ifdef HAVE_MAGIC_H
+static magic_t (*dl_magic_open)(int);
+static const char *(*dl_magic_file)(magic_t, const char *);
+static int (*dl_magic_load)(magic_t, const char *);
+static void (*dl_magic_close)(magic_t);
+
+/*
+ * NO_CHECK functionality was only added in file 4.20.
+ * Older systems like RHEL 5.x still have file 4.17
+ */
+#ifndef MAGIC_NO_CHECK_COMPRESS
+#define MAGIC_NO_CHECK_COMPRESS 0x0001000
+#endif
+#ifndef MAGIC_NO_CHECK_ELF
+#define MAGIC_NO_CHECK_ELF 0x0010000
+#endif
+
+#ifdef HAVE_DLOPEN
+#include <dlfcn.h>
+
+static void *magic_handle;
+
+static int magic_library_available(void)
+{
+	if (!magic_handle) {
+		magic_handle = dlopen("libmagic.so.1", RTLD_NOW);
+		if (!magic_handle)
+			return 0;
+
+		dl_magic_open = (magic_t (*)(int))
+			dlsym(magic_handle, "magic_open");
+		dl_magic_file = (const char *(*)(magic_t, const char *))
+			dlsym(magic_handle, "magic_file");
+		dl_magic_load = (int (*)(magic_t, const char *))
+			dlsym(magic_handle, "magic_load");
+		dl_magic_close = (void (*)(magic_t))
+			dlsym(magic_handle, "magic_close");
+	}
+
+	if (!dl_magic_open || !dl_magic_file ||
+	    !dl_magic_load || !dl_magic_close)
+		return 0;
+	return 1;
+}
+#else
+static int magic_library_available(void)
+{
+	dl_magic_open = magic_open;
+	dl_magic_file = magic_file;
+	dl_magic_load = magic_load;
+	dl_magic_close = magic_close;
+
+	return 1;
+}
+#endif
+#endif
+
+static void print_ext2_info(const char *device)
+
+{
+	struct ext2_super_block	*sb;
+	ext2_filsys		fs;
+	errcode_t		retval;
+	time_t			tm;
+
+	retval = ext2fs_open2(device, 0, EXT2_FLAG_64BITS, 0, 0,
+			      default_io_manager, &fs);
+	if (retval)
+		return;
+	sb = fs->super;
+
+	if (sb->s_mtime) {
+		tm = sb->s_mtime;
+		if (sb->s_last_mounted[0])
+			printf(_("\tlast mounted on %.*s on %s"),
+			       EXT2_LEN_STR(sb->s_last_mounted), ctime(&tm));
+		else
+			printf(_("\tlast mounted on %s"), ctime(&tm));
+	} else if (sb->s_mkfs_time) {
+		tm = sb->s_mkfs_time;
+		printf(_("\tcreated on %s"), ctime(&tm));
+	} else if (sb->s_wtime) {
+		tm = sb->s_wtime;
+		printf(_("\tlast modified on %s"), ctime(&tm));
+	}
+	ext2fs_close_free(&fs);
+}
+
+/*
+ * return 1 if there is no partition table, 0 if a partition table is
+ * detected, and -1 on an error.
+ */
+#ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS
+static int check_partition_table(const char *device)
+{
+	blkid_probe pr;
+	const char *value;
+	int ret;
+
+	pr = blkid_new_probe_from_filename(device);
+	if (!pr)
+		return -1;
+
+	ret = blkid_probe_enable_partitions(pr, 1);
+	if (ret < 0)
+		goto errout;
+
+	ret = blkid_probe_enable_superblocks(pr, 0);
+	if (ret < 0)
+		goto errout;
+
+	ret = blkid_do_fullprobe(pr);
+	if (ret < 0)
+		goto errout;
+
+	ret = blkid_probe_lookup_value(pr, "PTTYPE", &value, NULL);
+	if (ret == 0)
+		fprintf(stderr, _("Found a %s partition table in %s\n"),
+			value, device);
+	else
+		ret = 1;
+
+errout:
+	blkid_free_probe(pr);
+	return ret;
+}
+#else
+static int check_partition_table(const char *device EXT2FS_ATTR((unused)))
+{
+	return -1;
+}
+#endif
+
+/*
+ * return 1 if the device looks plausible, creating the file if necessary
+ */
+int check_plausibility(const char *device, int flags, int *ret_is_dev)
+{
+	int fd, ret, is_dev = 0;
+	ext2fs_struct_stat s;
+	int fl = O_RDONLY;
+	blkid_cache cache = NULL;
+	char *fs_type = NULL;
+	char *fs_label = NULL;
+
+	fd = ext2fs_open_file(device, fl, 0666);
+	if ((fd < 0) && (errno == ENOENT) && (flags & NO_SIZE)) {
+		fprintf(stderr, _("The file %s does not exist and no "
+				  "size was specified.\n"), device);
+		exit(1);
+	}
+	if ((fd < 0) && (errno == ENOENT) && (flags & CREATE_FILE)) {
+		fl |= O_CREAT;
+		fd = ext2fs_open_file(device, fl, 0666);
+		if (fd >= 0 && (flags & VERBOSE_CREATE))
+			printf(_("Creating regular file %s\n"), device);
+	}
+	if (fd < 0) {
+		fprintf(stderr, _("Could not open %s: %s\n"),
+			device, error_message(errno));
+		if (errno == ENOENT)
+			fputs(_("\nThe device apparently does not exist; "
+				"did you specify it correctly?\n"), stderr);
+		exit(1);
+	}
+
+	if (ext2fs_fstat(fd, &s) < 0) {
+		perror("stat");
+		exit(1);
+	}
+	close(fd);
+
+	if (S_ISBLK(s.st_mode))
+		is_dev = 1;
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+	/* On FreeBSD, all disk devices are character specials */
+	if (S_ISCHR(s.st_mode))
+		is_dev = 1;
+#endif
+	if (ret_is_dev)
+		*ret_is_dev = is_dev;
+
+	if ((flags & CHECK_BLOCK_DEV) && !is_dev) {
+		printf(_("%s is not a block special device.\n"), device);
+		return 0;
+	}
+
+	/*
+	 * Note: we use the older-style blkid API's here because we
+	 * want as much functionality to be available when using the
+	 * internal blkid library, when e2fsprogs is compiled for
+	 * non-Linux systems that will probably not have the libraries
+	 * from util-linux available.  We only use the newer
+	 * blkid-probe interfaces to access functionality not
+	 * available in the original blkid library.
+	 */
+	if ((flags & CHECK_FS_EXIST) && blkid_get_cache(&cache, NULL) >= 0) {
+		fs_type = blkid_get_tag_value(cache, "TYPE", device);
+		if (fs_type)
+			fs_label = blkid_get_tag_value(cache, "LABEL", device);
+		blkid_put_cache(cache);
+	}
+
+	if (fs_type) {
+		if (fs_label)
+			printf(_("%s contains a %s file system labelled '%s'\n"),
+			       device, fs_type, fs_label);
+		else
+			printf(_("%s contains a %s file system\n"), device,
+			       fs_type);
+		if (strncmp(fs_type, "ext", 3) == 0)
+			print_ext2_info(device);
+		free(fs_type);
+		free(fs_label);
+		return 0;
+	}
+
+#ifdef HAVE_MAGIC_H
+	if ((flags & CHECK_FS_EXIST) &&
+	    !getenv("E2FSPROGS_LIBMAGIC_SUPPRESS") &&
+	    magic_library_available()) {
+		const char *msg;
+		magic_t mag;
+		int has_magic = 0;
+
+		mag = dl_magic_open(MAGIC_RAW | MAGIC_SYMLINK | MAGIC_DEVICES |
+				    MAGIC_ERROR | MAGIC_NO_CHECK_ELF |
+				    MAGIC_NO_CHECK_COMPRESS);
+		dl_magic_load(mag, NULL);
+
+		msg = dl_magic_file(mag, device);
+		if (msg && strcmp(msg, "data") && strcmp(msg, "empty")) {
+			printf(_("%s contains `%s' data\n"), device, msg);
+			has_magic = 1;
+		}
+
+		dl_magic_close(mag);
+		return !has_magic;
+	}
+#endif
+	if (flags & CHECK_FS_EXIST) {
+		ret = check_partition_table(device);
+		if (ret >= 0)
+			return ret;
+	}
+	return 1;
+}
+