Initial import

1 files changed, 309 insertions, 0 deletions

diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
new file mode 100644
index 000000000..2f7a3c090
--- /dev/null
+++ b/fs/jffs2/acl.c
@@ -0,0 +1,309 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2006  NEC Corporation
+ *
+ * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/crc32.h>
+#include <linux/jffs2.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/mtd/mtd.h>
+#include "nodelist.h"
+
+static size_t jffs2_acl_size(int count)
+{
+	if (count <= 4) {
+		return sizeof(struct jffs2_acl_header)
+		       + count * sizeof(struct jffs2_acl_entry_short);
+	} else {
+		return sizeof(struct jffs2_acl_header)
+		       + 4 * sizeof(struct jffs2_acl_entry_short)
+		       + (count - 4) * sizeof(struct jffs2_acl_entry);
+	}
+}
+
+static int jffs2_acl_count(size_t size)
+{
+	size_t s;
+
+	size -= sizeof(struct jffs2_acl_header);
+	if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
+		if (size % sizeof(struct jffs2_acl_entry_short))
+			return -1;
+		return size / sizeof(struct jffs2_acl_entry_short);
+	} else {
+		s = size - 4 * sizeof(struct jffs2_acl_entry_short);
+		if (s % sizeof(struct jffs2_acl_entry))
+			return -1;
+		return s / sizeof(struct jffs2_acl_entry) + 4;
+	}
+}
+
+static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
+{
+	void *end = value + size;
+	struct jffs2_acl_header *header = value;
+	struct jffs2_acl_entry *entry;
+	struct posix_acl *acl;
+	uint32_t ver;
+	int i, count;
+
+	if (!value)
+		return NULL;
+	if (size < sizeof(struct jffs2_acl_header))
+		return ERR_PTR(-EINVAL);
+	ver = je32_to_cpu(header->a_version);
+	if (ver != JFFS2_ACL_VERSION) {
+		JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
+		return ERR_PTR(-EINVAL);
+	}
+
+	value += sizeof(struct jffs2_acl_header);
+	count = jffs2_acl_count(size);
+	if (count < 0)
+		return ERR_PTR(-EINVAL);
+	if (count == 0)
+		return NULL;
+
+	acl = posix_acl_alloc(count, GFP_KERNEL);
+	if (!acl)
+		return ERR_PTR(-ENOMEM);
+
+	for (i=0; i < count; i++) {
+		entry = value;
+		if (value + sizeof(struct jffs2_acl_entry_short) > end)
+			goto fail;
+		acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
+		acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
+		switch (acl->a_entries[i].e_tag) {
+			case ACL_USER_OBJ:
+			case ACL_GROUP_OBJ:
+			case ACL_MASK:
+			case ACL_OTHER:
+				value += sizeof(struct jffs2_acl_entry_short);
+				break;
+
+			case ACL_USER:
+				value += sizeof(struct jffs2_acl_entry);
+				if (value > end)
+					goto fail;
+				acl->a_entries[i].e_uid =
+					make_kuid(&init_user_ns,
+						  je32_to_cpu(entry->e_id));
+				break;
+			case ACL_GROUP:
+				value += sizeof(struct jffs2_acl_entry);
+				if (value > end)
+					goto fail;
+				acl->a_entries[i].e_gid =
+					make_kgid(&init_user_ns,
+						  je32_to_cpu(entry->e_id));
+				break;
+
+			default:
+				goto fail;
+		}
+	}
+	if (value != end)
+		goto fail;
+	return acl;
+ fail:
+	posix_acl_release(acl);
+	return ERR_PTR(-EINVAL);
+}
+
+static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
+{
+	struct jffs2_acl_header *header;
+	struct jffs2_acl_entry *entry;
+	void *e;
+	size_t i;
+
+	*size = jffs2_acl_size(acl->a_count);
+	header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
+	if (!header)
+		return ERR_PTR(-ENOMEM);
+	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
+	e = header + 1;
+	for (i=0; i < acl->a_count; i++) {
+		const struct posix_acl_entry *acl_e = &acl->a_entries[i];
+		entry = e;
+		entry->e_tag = cpu_to_je16(acl_e->e_tag);
+		entry->e_perm = cpu_to_je16(acl_e->e_perm);
+		switch(acl_e->e_tag) {
+			case ACL_USER:
+				entry->e_id = cpu_to_je32(
+					from_kuid(&init_user_ns, acl_e->e_uid));
+				e += sizeof(struct jffs2_acl_entry);
+				break;
+			case ACL_GROUP:
+				entry->e_id = cpu_to_je32(
+					from_kgid(&init_user_ns, acl_e->e_gid));
+				e += sizeof(struct jffs2_acl_entry);
+				break;
+
+			case ACL_USER_OBJ:
+			case ACL_GROUP_OBJ:
+			case ACL_MASK:
+			case ACL_OTHER:
+				e += sizeof(struct jffs2_acl_entry_short);
+				break;
+
+			default:
+				goto fail;
+		}
+	}
+	return header;
+ fail:
+	kfree(header);
+	return ERR_PTR(-EINVAL);
+}
+
+struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
+{
+	struct posix_acl *acl;
+	char *value = NULL;
+	int rc, xprefix;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
+		break;
+	case ACL_TYPE_DEFAULT:
+		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
+		break;
+	default:
+		BUG();
+	}
+	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
+	if (rc > 0) {
+		value = kmalloc(rc, GFP_KERNEL);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
+	}
+	if (rc > 0) {
+		acl = jffs2_acl_from_medium(value, rc);
+	} else if (rc == -ENODATA || rc == -ENOSYS) {
+		acl = NULL;
+	} else {
+		acl = ERR_PTR(rc);
+	}
+	kfree(value);
+	if (!IS_ERR(acl))
+		set_cached_acl(inode, type, acl);
+	return acl;
+}
+
+static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
+{
+	char *value = NULL;
+	size_t size = 0;
+	int rc;
+
+	if (acl) {
+		value = jffs2_acl_to_medium(acl, &size);
+		if (IS_ERR(value))
+			return PTR_ERR(value);
+	}
+	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
+	if (!value && rc == -ENODATA)
+		rc = 0;
+	kfree(value);
+
+	return rc;
+}
+
+int jffs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	int rc, xprefix;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
+		if (acl) {
+			umode_t mode = inode->i_mode;
+			rc = posix_acl_equiv_mode(acl, &mode);
+			if (rc < 0)
+				return rc;
+			if (inode->i_mode != mode) {
+				struct iattr attr;
+
+				attr.ia_valid = ATTR_MODE | ATTR_CTIME;
+				attr.ia_mode = mode;
+				attr.ia_ctime = CURRENT_TIME_SEC;
+				rc = jffs2_do_setattr(inode, &attr);
+				if (rc < 0)
+					return rc;
+			}
+			if (rc == 0)
+				acl = NULL;
+		}
+		break;
+	case ACL_TYPE_DEFAULT:
+		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EACCES : 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+	rc = __jffs2_set_acl(inode, xprefix, acl);
+	if (!rc)
+		set_cached_acl(inode, type, acl);
+	return rc;
+}
+
+int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, umode_t *i_mode)
+{
+	struct posix_acl *default_acl, *acl;
+	int rc;
+
+	cache_no_acl(inode);
+
+	rc = posix_acl_create(dir_i, i_mode, &default_acl, &acl);
+	if (rc)
+		return rc;
+
+	if (default_acl) {
+		set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
+		posix_acl_release(default_acl);
+	}
+	if (acl) {
+		set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
+		posix_acl_release(acl);
+	}
+	return 0;
+}
+
+int jffs2_init_acl_post(struct inode *inode)
+{
+	int rc;
+
+	if (inode->i_default_acl) {
+		rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
+		if (rc)
+			return rc;
+	}
+
+	if (inode->i_acl) {
+		rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}