ubifs-utils: Split common source files from mkfs.ubifs

Split common source files into common dir from mkfs.ubifs, this is a
preparation for importing libubifs(from linux kernel) to replace
current UBIFS libs.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 535 insertions, 0 deletions

diff --git a/ubifs-utils/common/devtable.c b/ubifs-utils/common/devtable.c
new file mode 100644
index 0000000..aa815fb
--- /dev/null
+++ b/ubifs-utils/common/devtable.c
@@ -0,0 +1,535 @@
+/*
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Author: Artem Bityutskiy
+ *
+ * Part of the device table parsing code was taken from the mkfs.jffs2 utility.
+ * The original author of that code is Erik Andersen, hence:
+ *	Copyright (C) 2001, 2002 Erik Andersen <andersen@codepoet.org>
+ */
+
+/*
+ * This file implemented device table support. Device table entries take the
+ * form of:
+ * <path>    <type> <mode> <uid> <gid> <major> <minor> <start>	<inc> <count>
+ * /dev/mem  c       640   0     0     1       1       0        0     -
+ *
+ * Type can be one of:
+ * f  A regular file
+ * d  Directory
+ * c  Character special device file
+ * b  Block special device file
+ * p  Fifo (named pipe)
+ * l  Link
+ *
+ * Don't bother with hard links (special cases of regular files), or sockets
+ * (why bother).
+ *
+ * Regular files must exist in the target root directory. If a char, block,
+ * fifo, or directory does not exist, it will be created.
+ *
+ * Please, refer the device_table.txt file which can be found at MTD utilities
+ * for more information about what the device table is.
+ */
+
+#include "mkfs.ubifs.h"
+#include "hashtable/hashtable.h"
+#include "hashtable/hashtable_itr.h"
+
+/*
+ * The hash table which contains paths to files/directories/device nodes
+ * referred to in the device table. For example, if the device table refers
+ * "/dev/loop0", the @path_htbl will contain "/dev" element.
+ */
+static struct hashtable *path_htbl;
+
+/* Hash function used for hash tables */
+static unsigned int r5_hash(void *s)
+{
+	unsigned int a = 0;
+	const signed char *str = s;
+
+	while (*str) {
+		a += *str << 4;
+		a += *str >> 4;
+		a *= 11;
+		str++;
+	}
+
+	return a;
+}
+
+/*
+ * Check whether 2 keys of a hash table are equivalent. The keys are path/file
+ * names, so we simply use 'strcmp()'.
+ */
+static int is_equivalent(void *k1, void *k2)
+{
+	return !strcmp(k1, k2);
+}
+
+/**
+ * separate_last - separate out the last path component
+ * @buf: the path to split
+ * @len: length of the @buf string
+ * @path: the beginning of path is returned here
+ * @name: the last path component is returned here
+ *
+ * This helper function separates out the the last component of the full path
+ * string. For example, "/dev/loop" would be split on "/dev" and "loop". This
+ * function allocates memory for @path and @name and return the result there.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int separate_last(const char *buf, int len, char **path, char **name)
+{
+	int path_len = len, name_len;
+	const char *p = buf + len, *n;
+
+	while (*--p != '/')
+		path_len -= 1;
+
+	/* Drop the final '/' unless this is the root directory */
+	name_len = len - path_len;
+	n = buf + path_len;
+	if (path_len > 1)
+		path_len -= 1;
+
+	*path = malloc(path_len + 1);
+	if (!*path)
+		return err_msg("cannot allocate %d bytes of memory",
+			       path_len + 1);
+	memcpy(*path, buf, path_len);
+	(*path)[path_len] = '\0';
+
+	*name = malloc(name_len + 1);
+	if (!*name) {
+		free(*path);
+		return err_msg("cannot allocate %d bytes of memory",
+			       name_len + 1);
+	}
+	memcpy(*name, n, name_len + 1);
+
+	return 0;
+}
+
+static int interpret_table_entry(const char *line)
+{
+	char buf[1024], type, *path = NULL, *name = NULL;
+	int len;
+	struct path_htbl_element *ph_elt = NULL;
+	struct name_htbl_element *nh_elt = NULL;
+	unsigned int mode = 0755, uid = 0, gid = 0, major = 0, minor = 0;
+	unsigned int start = 0, increment = 0, count = 0;
+
+	if (sscanf(line, "%1023s %c %o %u %u %u %u %u %u %u",
+		   buf, &type, &mode, &uid, &gid, &major, &minor,
+		   &start, &increment, &count) < 0)
+		return sys_err_msg("sscanf failed");
+
+	dbg_msg(3, "name %s, type %c, mode %o, uid %u, gid %u, major %u, "
+		"minor %u, start %u, inc %u, cnt %u",
+		buf, type, mode, uid, gid, major, minor, start,
+		increment, count);
+
+	len = strnlen(buf, 1024);
+	if (len == 0)
+		return err_msg("empty path");
+	if (len == 1024)
+		return err_msg("too long path");
+
+	if (buf[0] != '/')
+		return err_msg("device table entries require absolute paths");
+	if (strstr(buf, "//"))
+		return err_msg("'//' cannot be used in the path");
+	if (len > 1 && buf[len - 1] == '/')
+		return err_msg("do not put '/' at the end");
+
+	if (strstr(buf, "/./") || strstr(buf, "/../") ||
+	    !strcmp(buf + len - 2, "/.") || !strcmp(buf + len - 3, "/.."))
+		return err_msg("'.' and '..' cannot be used in the path");
+
+	switch (type) {
+		case 'd':
+			mode |= S_IFDIR;
+			break;
+		case 'f':
+			mode |= S_IFREG;
+			break;
+		case 'p':
+			mode |= S_IFIFO;
+			break;
+		case 'c':
+			mode |= S_IFCHR;
+			break;
+		case 'b':
+			mode |= S_IFBLK;
+			break;
+		case 'l':
+			mode |= S_IFLNK;
+			if ((mode & 0777) != 0777)
+				return err_msg("link permission must be 0777");
+			break;
+		default:
+			return err_msg("unsupported file type '%c'", type);
+	}
+
+	if (separate_last(buf, len, &path, &name))
+		return -1;
+
+	/*
+	 * Check if this path already exist in the path hash table and add it
+	 * if it is not.
+	 */
+	ph_elt = hashtable_search(path_htbl, path);
+	if (!ph_elt) {
+		dbg_msg(3, "inserting '%s' into path hash table", path);
+		ph_elt = malloc(sizeof(struct path_htbl_element));
+		if (!ph_elt) {
+			err_msg("cannot allocate %zd bytes of memory",
+				sizeof(struct path_htbl_element));
+			goto out_free;
+		}
+
+		if (!hashtable_insert(path_htbl, path, ph_elt)) {
+			err_msg("cannot insert into path hash table");
+			goto out_free;
+		}
+
+		ph_elt->path = path;
+		path = NULL;
+		ph_elt->name_htbl = create_hashtable(128, &r5_hash,
+						     &is_equivalent);
+		if (!ph_elt->name_htbl) {
+			err_msg("cannot create name hash table");
+			goto out_free;
+		}
+	}
+
+	if (increment != 0 && count == 0) {
+		err_msg("count cannot be zero if increment is non-zero");
+		goto out_free;
+	}
+
+	/*
+	 * Add the file/directory/device node (last component of the path) to
+	 * the name hashtable. The name hashtable resides in the corresponding
+	 * path hashtable element.
+	 */
+
+	if (count == 0) {
+		/* This entry does not require any iterating */
+		nh_elt = malloc(sizeof(struct name_htbl_element));
+		if (!nh_elt) {
+			err_msg("cannot allocate %zd bytes of memory",
+				sizeof(struct name_htbl_element));
+			goto out_free;
+		}
+
+		nh_elt->mode = mode;
+		nh_elt->uid = uid;
+		nh_elt->gid = gid;
+		nh_elt->dev = makedev(major, minor);
+
+		dbg_msg(3, "inserting '%s' into name hash table (major %d, minor %d)",
+			name, major(nh_elt->dev), minor(nh_elt->dev));
+
+		if (hashtable_search(ph_elt->name_htbl, name)) {
+			err_msg("'%s' is referred twice", buf);
+			goto out_free;
+		}
+
+		nh_elt->name = name;
+		if (!hashtable_insert(ph_elt->name_htbl, name, nh_elt)) {
+			err_msg("cannot insert into name hash table");
+			goto out_free;
+		}
+	} else {
+		int i, num = start + count, len = strlen(name) + 20;
+		char *nm;
+
+		for (i = start; i < num; i++) {
+			nh_elt = malloc(sizeof(struct name_htbl_element));
+			if (!nh_elt) {
+				err_msg("cannot allocate %zd bytes of memory",
+					sizeof(struct name_htbl_element));
+				goto out_free;
+			}
+
+			nh_elt->mode = mode;
+			nh_elt->uid = uid;
+			nh_elt->gid = gid;
+			nh_elt->dev = makedev(major, minor + (i - start) * increment);
+
+			nm = malloc(len);
+			if (!nm) {
+				err_msg("cannot allocate %d bytes of memory", len);
+				goto out_free;
+			}
+
+			sprintf(nm, "%s%d", name, i);
+			nh_elt->name = nm;
+
+			dbg_msg(3, "inserting '%s' into name hash table (major %d, minor %d)",
+			        nm, major(nh_elt->dev), minor(nh_elt->dev));
+
+			if (hashtable_search(ph_elt->name_htbl, nm)) {
+				err_msg("'%s' is referred twice", buf);
+				free (nm);
+				goto out_free;
+			}
+
+			if (!hashtable_insert(ph_elt->name_htbl, nm, nh_elt)) {
+				err_msg("cannot insert into name hash table");
+				free (nm);
+				goto out_free;
+			}
+		}
+		free(name);
+		name = NULL;
+	}
+
+	return 0;
+
+out_free:
+	free(ph_elt);
+	free(nh_elt);
+	free(path);
+	free(name);
+	return -1;
+}
+
+/**
+ * parse_devtable - parse the device table.
+ * @tbl_file: device table file name
+ *
+ * This function parses the device table and prepare the hash table which will
+ * later be used by mkfs.ubifs to create the specified files/device nodes.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+int parse_devtable(const char *tbl_file)
+{
+	FILE *f;
+	char *line = NULL;
+	struct stat st;
+	size_t len;
+
+	dbg_msg(1, "parsing device table file '%s'", tbl_file);
+
+	path_htbl = create_hashtable(128, &r5_hash, &is_equivalent);
+	if (!path_htbl)
+		return err_msg("cannot create path hash table");
+
+	f = fopen(tbl_file, "r");
+	if (!f)
+		return sys_err_msg("cannot open '%s'", tbl_file);
+
+	if (fstat(fileno(f), &st) < 0) {
+		sys_err_msg("cannot stat '%s'", tbl_file);
+		goto out_close;
+	}
+
+	if (st.st_size < 10) {
+		sys_err_msg("'%s' is too short", tbl_file);
+		goto out_close;
+	}
+
+	/*
+	 * The general plan now is to read in one line at a time, check for
+	 * leading comment delimiters ('#'), then try and parse the line as a
+	 * device table
+	 */
+	while (getline(&line, &len, f) != -1) {
+		/* First trim off any white-space */
+		len = strlen(line);
+
+		/* Trim trailing white-space */
+		while (len > 0 && isspace(line[len - 1]))
+			line[--len] = '\0';
+		/* Trim leading white-space */
+		memmove(line, &line[strspn(line, " \n\r\t\v")], len);
+
+		/* How long are we after trimming? */
+		len = strlen(line);
+
+		/* If this is not a comment line, try to interpret it */
+		if (len && *line != '#') {
+			if (interpret_table_entry(line)) {
+				err_msg("cannot parse '%s'", line);
+				goto out_close;
+			}
+		}
+
+		free(line);
+		line = NULL;
+	}
+
+	dbg_msg(1, "finished parsing");
+	fclose(f);
+	return 0;
+
+out_close:
+	fclose(f);
+	free_devtable_info();
+	return -1;
+}
+
+/**
+ * devtbl_find_path - find a path in the path hash table.
+ * @path: UBIFS path to find.
+ *
+ * This looks up the path hash table. Returns the path hash table element
+ * reference if @path was found and %NULL if not.
+ */
+struct path_htbl_element *devtbl_find_path(const char *path)
+{
+	if (!path_htbl)
+		return NULL;
+
+	return hashtable_search(path_htbl, (void *)path);
+}
+
+/**
+ * devtbl_find_name - find a name in the name hash table.
+ * @ph_etl: path hash table element to find at
+ * @name: name to find
+ *
+ * This looks up the name hash table. Returns the name hash table element
+ * reference if @name found and %NULL if not.
+ */
+struct name_htbl_element *devtbl_find_name(struct path_htbl_element *ph_elt,
+					   const char *name)
+{
+	if (!path_htbl)
+		return NULL;
+
+	return hashtable_search(ph_elt->name_htbl, (void *)name);
+}
+
+/**
+ * override_attributes - override inode attributes.
+ * @st: struct stat object to containing the attributes to override
+ * @ph_elt: path hash table element object
+ * @nh_elt: name hash table element object containing the new values
+ *
+ * The device table file may override attributes like UID of files. For
+ * example, the device table may contain a "/dev" entry, and the UBIFS FS on
+ * the host may contain "/dev" directory. In this case the attributes of the
+ * "/dev" directory inode has to be as the device table specifies.
+ *
+ * Note, the hash element is removed by this function as well.
+ */
+int override_attributes(struct stat *st, struct path_htbl_element *ph_elt,
+			struct name_htbl_element *nh_elt)
+{
+	if (!path_htbl)
+		return 0;
+
+	if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode) ||
+	    S_ISFIFO(st->st_mode))
+		return err_msg("%s/%s both exists at UBIFS root at host, "
+			       "and is referred from the device table",
+			       strcmp(ph_elt->path, "/") ? ph_elt->path : "",
+			       nh_elt->name);
+
+	if ((st->st_mode & S_IFMT) != (nh_elt->mode & S_IFMT))
+		return err_msg("%s/%s is referred from the device table also exists in "
+			       "the UBIFS root directory at host, but the file type is "
+			       "different", strcmp(ph_elt->path, "/") ? ph_elt->path : "",
+			       nh_elt->name);
+
+	dbg_msg(3, "set UID %d, GID %d, mode %o for %s/%s as device table says",
+		nh_elt->uid, nh_elt->gid, nh_elt->mode, ph_elt->path, nh_elt->name);
+
+	st->st_uid = nh_elt->uid;
+	st->st_gid = nh_elt->gid;
+	st->st_mode = nh_elt->mode;
+
+	hashtable_remove(ph_elt->name_htbl, (void *)nh_elt->name);
+	return 0;
+}
+
+/**
+ * first_name_htbl_element - return first element of the name hash table.
+ * @ph_elt: the path hash table the name hash table belongs to
+ * @itr: double pointer to a 'struct hashtable_itr' object where the
+ *       information about further iterations is stored
+ *
+ * This function implements name hash table iteration together with
+ * 'next_name_htbl_element()'. Returns the first name hash table element or
+ * %NULL if the hash table is empty.
+ */
+struct name_htbl_element *
+first_name_htbl_element(struct path_htbl_element *ph_elt,
+			struct hashtable_itr **itr)
+{
+	if (!path_htbl || !ph_elt || hashtable_count(ph_elt->name_htbl) == 0)
+		return NULL;
+
+	*itr = hashtable_iterator(ph_elt->name_htbl);
+	return hashtable_iterator_value(*itr);
+}
+
+/**
+ * first_name_htbl_element - return next element of the name hash table.
+ * @ph_elt: the path hash table the name hash table belongs to
+ * @itr: double pointer to a 'struct hashtable_itr' object where the
+ *       information about further iterations is stored
+ *
+ * This function implements name hash table iteration together with
+ * 'first_name_htbl_element()'. Returns the next name hash table element or
+ * %NULL if there are no more elements.
+ */
+struct name_htbl_element *
+next_name_htbl_element(struct path_htbl_element *ph_elt,
+		       struct hashtable_itr **itr)
+{
+	if (!path_htbl || !ph_elt || !hashtable_iterator_advance(*itr))
+		return NULL;
+
+	return hashtable_iterator_value(*itr);
+}
+
+/**
+ * free_devtable_info - free device table information.
+ *
+ * This function frees the path hash table and the name hash tables.
+ */
+void free_devtable_info(void)
+{
+	struct hashtable_itr *ph_itr;
+	struct path_htbl_element *ph_elt;
+
+	if (!path_htbl)
+		return;
+
+	if (hashtable_count(path_htbl) > 0) {
+		ph_itr = hashtable_iterator(path_htbl);
+		do {
+			ph_elt = hashtable_iterator_value(ph_itr);
+			/*
+			 * Note, since we use the same string for the key and
+			 * @name in the name hash table elements, we do not
+			 * have to iterate name hash table because @name memory
+			 * will be freed when freeing the key.
+			 */
+			hashtable_destroy(ph_elt->name_htbl, 1);
+		} while (hashtable_iterator_advance(ph_itr));
+		free(ph_itr);
+	}
+	hashtable_destroy(path_htbl, 1);
+}