9d8f13ba3f
This patch changes the security_inode_init_security API by adding a filesystem specific callback to write security extended attributes. This change is in preparation for supporting the initialization of multiple LSM xattrs and the EVM xattr. Initially the callback function walks an array of xattrs, writing each xattr separately, but could be optimized to write multiple xattrs at once. For existing security_inode_init_security() calls, which have not yet been converted to use the new callback function, such as those in reiserfs and ocfs2, this patch defines security_old_inode_init_security(). Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
121 lines
3.0 KiB
C
121 lines
3.0 KiB
C
#include <linux/reiserfs_fs.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/xattr.h>
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#include <linux/slab.h>
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#include <linux/reiserfs_xattr.h>
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#include <linux/security.h>
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#include <asm/uaccess.h>
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static int
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security_get(struct dentry *dentry, const char *name, void *buffer, size_t size,
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int handler_flags)
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{
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if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
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return -EINVAL;
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if (IS_PRIVATE(dentry->d_inode))
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return -EPERM;
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return reiserfs_xattr_get(dentry->d_inode, name, buffer, size);
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}
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static int
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security_set(struct dentry *dentry, const char *name, const void *buffer,
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size_t size, int flags, int handler_flags)
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{
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if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
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return -EINVAL;
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if (IS_PRIVATE(dentry->d_inode))
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return -EPERM;
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return reiserfs_xattr_set(dentry->d_inode, name, buffer, size, flags);
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}
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static size_t security_list(struct dentry *dentry, char *list, size_t list_len,
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const char *name, size_t namelen, int handler_flags)
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{
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const size_t len = namelen + 1;
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if (IS_PRIVATE(dentry->d_inode))
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return 0;
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if (list && len <= list_len) {
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memcpy(list, name, namelen);
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list[namelen] = '\0';
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}
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return len;
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}
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/* Initializes the security context for a new inode and returns the number
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* of blocks needed for the transaction. If successful, reiserfs_security
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* must be released using reiserfs_security_free when the caller is done. */
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int reiserfs_security_init(struct inode *dir, struct inode *inode,
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const struct qstr *qstr,
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struct reiserfs_security_handle *sec)
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{
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int blocks = 0;
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int error;
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sec->name = NULL;
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/* Don't add selinux attributes on xattrs - they'll never get used */
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if (IS_PRIVATE(dir))
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return 0;
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error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
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&sec->value, &sec->length);
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if (error) {
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if (error == -EOPNOTSUPP)
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error = 0;
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sec->name = NULL;
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sec->value = NULL;
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sec->length = 0;
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return error;
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}
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if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
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blocks = reiserfs_xattr_jcreate_nblocks(inode) +
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reiserfs_xattr_nblocks(inode, sec->length);
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/* We don't want to count the directories twice if we have
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* a default ACL. */
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REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
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}
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return blocks;
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}
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int reiserfs_security_write(struct reiserfs_transaction_handle *th,
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struct inode *inode,
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struct reiserfs_security_handle *sec)
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{
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int error;
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if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
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return -EINVAL;
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error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
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sec->length, XATTR_CREATE);
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if (error == -ENODATA || error == -EOPNOTSUPP)
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error = 0;
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return error;
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}
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void reiserfs_security_free(struct reiserfs_security_handle *sec)
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{
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kfree(sec->name);
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kfree(sec->value);
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sec->name = NULL;
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sec->value = NULL;
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}
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const struct xattr_handler reiserfs_xattr_security_handler = {
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.prefix = XATTR_SECURITY_PREFIX,
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.get = security_get,
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.set = security_set,
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.list = security_list,
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};
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