#include <linux/smp_lock.h>
#include <linux/personality.h>
#include <linux/security.h>
+#include <linux/syscalls.h>
#include <linux/mount.h>
#include <linux/audit.h>
-#include <linux/vs_base.h>
+#include <linux/proc_fs.h>
+#include <linux/vserver/inode.h>
+#include <linux/vserver/debug.h>
#include <asm/namei.h>
#include <asm/uaccess.h>
int retval;
unsigned long len = PATH_MAX;
- if ((unsigned long) filename >= TASK_SIZE) {
- if (!segment_eq(get_fs(), KERNEL_DS))
+ if (!segment_eq(get_fs(), KERNEL_DS)) {
+ if ((unsigned long) filename >= TASK_SIZE)
return -EFAULT;
- } else if (TASK_SIZE - (unsigned long) filename < PATH_MAX)
- len = TASK_SIZE - (unsigned long) filename;
+ if (TASK_SIZE - (unsigned long) filename < PATH_MAX)
+ len = TASK_SIZE - (unsigned long) filename;
+ }
- retval = strncpy_from_user((char *)page, filename, len);
+ retval = strncpy_from_user(page, filename, len);
if (retval > 0) {
if (retval < len)
return 0;
return result;
}
-/*
- * vfs_permission()
+/**
+ * generic_permission - check for access rights on a Posix-like filesystem
+ * @inode: inode to check access rights for
+ * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
+ * @check_acl: optional callback to check for Posix ACLs
*
- * is used to check for read/write/execute permissions on a file.
+ * Used to check for read/write/execute permissions on a file.
* We use "fsuid" for this, letting us set arbitrary permissions
* for filesystem access without changing the "normal" uids which
* are used for other things..
*/
-int vfs_permission(struct inode * inode, int mask)
+int generic_permission(struct inode *inode, int mask,
+ int (*check_acl)(struct inode *inode, int mask))
{
umode_t mode = inode->i_mode;
- if (mask & MAY_WRITE) {
- /*
- * Nobody gets write access to a read-only fs.
- */
- if (IS_RDONLY(inode) &&
- (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
- return -EROFS;
-
- /*
- * Nobody gets write access to an immutable file.
- */
- if (IS_IMMUTABLE(inode))
- return -EACCES;
- }
-
if (current->fsuid == inode->i_uid)
mode >>= 6;
- else if (in_group_p(inode->i_gid))
- mode >>= 3;
+ else {
+ if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
+ int error = check_acl(inode, mask);
+ if (error == -EACCES)
+ goto check_capabilities;
+ else if (error != -EAGAIN)
+ return error;
+ }
+
+ if (in_group_p(inode->i_gid))
+ mode >>= 3;
+ }
/*
* If the DACs are ok we don't need any capability check.
if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
return 0;
+ check_capabilities:
/*
* Read/write DACs are always overridable.
* Executable DACs are overridable if at least one exec bit is set.
static inline int xid_permission(struct inode *inode, int mask, struct nameidata *nd)
{
+ if (IS_BARRIER(inode) && !vx_check(0, VX_ADMIN)) {
+ vxwprintk(1, "xid=%d did hit the barrier.",
+ vx_current_xid());
+ return -EACCES;
+ }
if (inode->i_xid == 0)
return 0;
if (vx_check(inode->i_xid, VX_ADMIN|VX_WATCH|VX_IDENT))
return 0;
-/*
- printk("VSW: xid=%d denied access to %p[#%d,%lu] »%*s«.\n",
+
+ vxwprintk(1, "xid=%d denied access to %p[#%d,%lu] »%s«.",
vx_current_xid(), inode, inode->i_xid, inode->i_ino,
- nd->dentry->d_name.len, nd->dentry->d_name.name);
-*/
+ vxd_path(nd->dentry, nd->mnt));
return -EACCES;
}
-int permission(struct inode * inode,int mask, struct nameidata *nd)
+int permission(struct inode *inode, int mask, struct nameidata *nd)
{
- int retval;
- int submask;
+ int retval, submask;
+
+ if (mask & MAY_WRITE) {
+ umode_t mode = inode->i_mode;
+
+ /*
+ * Nobody gets write access to a read-only fs.
+ */
+ if (IS_RDONLY(inode) &&
+ (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
+ return -EROFS;
+
+ /*
+ * Nobody gets write access to an immutable file.
+ */
+ if (IS_IMMUTABLE(inode))
+ return -EACCES;
+ }
+
/* Ordinary permission routines do not understand MAY_APPEND. */
submask = mask & ~MAY_APPEND;
-
if ((retval = xid_permission(inode, mask, nd)))
return retval;
if (inode->i_op && inode->i_op->permission)
retval = inode->i_op->permission(inode, submask, nd);
else
- retval = vfs_permission(inode, submask);
+ retval = generic_permission(inode, submask, NULL);
if (retval)
return retval;
/*
* Short-cut version of permission(), for calling by
* path_walk(), when dcache lock is held. Combines parts
- * of permission() and vfs_permission(), and tests ONLY for
+ * of permission() and generic_permission(), and tests ONLY for
* MAY_EXEC permission.
*
* If appropriate, check DAC only. If not appropriate, or
return PTR_ERR(link);
}
+static inline int __do_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ int error;
+
+ touch_atime(nd->mnt, dentry);
+ nd_set_link(nd, NULL);
+ error = dentry->d_inode->i_op->follow_link(dentry, nd);
+ if (!error) {
+ char *s = nd_get_link(nd);
+ if (s)
+ error = __vfs_follow_link(nd, s);
+ if (dentry->d_inode->i_op->put_link)
+ dentry->d_inode->i_op->put_link(dentry, nd);
+ }
+
+ return error;
+}
+
/*
* This limits recursive symlink follows to 8, while
* limiting consecutive symlinks to 40.
current->link_count++;
current->total_link_count++;
nd->depth++;
- touch_atime(nd->mnt, dentry);
- nd_set_link(nd, NULL);
- err = dentry->d_inode->i_op->follow_link(dentry, nd);
- if (!err) {
- char *s = nd_get_link(nd);
- if (s)
- err = __vfs_follow_link(nd, s);
- if (dentry->d_inode->i_op->put_link)
- dentry->d_inode->i_op->put_link(dentry, nd);
- }
+ err = __do_follow_link(dentry, nd);
current->link_count--;
nd->depth--;
return err;
if (*dentry == current->fs->root &&
*mnt == current->fs->rootmnt) {
read_unlock(¤t->fs->lock);
- break;
+ return;
}
read_unlock(¤t->fs->lock);
spin_lock(&dcache_lock);
{
struct vfsmount *mnt = nd->mnt;
struct dentry *dentry = __d_lookup(nd->dentry, name);
+ struct inode *inode;
if (!dentry)
goto need_lookup;
if (dentry->d_op && dentry->d_op->d_revalidate)
goto need_revalidate;
+ inode = dentry->d_inode;
+ if (!inode)
+ goto done;
+ if (!vx_check(inode->i_xid, VX_WATCH|VX_ADMIN|VX_HOSTID|VX_IDENT))
+ goto hidden;
+ if (inode->i_sb->s_magic == PROC_SUPER_MAGIC) {
+ struct proc_dir_entry *de = PDE(inode);
+
+ if (de && !vx_hide_check(0, de->vx_flags))
+ goto hidden;
+ }
done:
path->mnt = mnt;
path->dentry = dentry;
return 0;
+hidden:
+ vxwprintk(1, "xid=%d did lookup hidden %p[#%d,%lu] »%s«.",
+ vx_current_xid(), inode, inode->i_xid, inode->i_ino,
+ vxd_path(dentry, mnt));
+ dput(dentry);
+ return -ENOENT;
need_lookup:
dentry = real_lookup(nd->dentry, name, nd);
error = security_inode_follow_link(dentry, nd);
if (error)
goto exit_dput;
- touch_atime(nd->mnt, dentry);
- nd_set_link(nd, NULL);
- error = dentry->d_inode->i_op->follow_link(dentry, nd);
- if (!error) {
- char *s = nd_get_link(nd);
- if (s)
- error = __vfs_follow_link(nd, s);
- if (dentry->d_inode->i_op->put_link)
- dentry->d_inode->i_op->put_link(dentry, nd);
- }
+ error = __do_follow_link(dentry, nd);
dput(dentry);
if (error)
return error;
}
}
-int page_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct page *page = NULL;
- char *s = page_getlink(dentry, &page);
- int res = __vfs_follow_link(nd, s);
- if (page) {
- kunmap(page);
- page_cache_release(page);
- }
- return res;
-}
-
int page_symlink(struct inode *inode, const char *symname, int len)
{
struct address_space *mapping = inode->i_mapping;
EXPORT_SYMBOL(get_write_access); /* binfmt_aout */
EXPORT_SYMBOL(getname);
EXPORT_SYMBOL(lock_rename);
-EXPORT_SYMBOL(lookup_create);
EXPORT_SYMBOL(lookup_hash);
EXPORT_SYMBOL(lookup_one_len);
-EXPORT_SYMBOL(page_follow_link);
EXPORT_SYMBOL(page_follow_link_light);
EXPORT_SYMBOL(page_put_link);
EXPORT_SYMBOL(page_readlink);
EXPORT_SYMBOL(vfs_link);
EXPORT_SYMBOL(vfs_mkdir);
EXPORT_SYMBOL(vfs_mknod);
-EXPORT_SYMBOL(vfs_permission);
+EXPORT_SYMBOL(generic_permission);
EXPORT_SYMBOL(vfs_readlink);
EXPORT_SYMBOL(vfs_rename);
EXPORT_SYMBOL(vfs_rmdir);
git://git.onelab.eu / linux-2.6.git / blobdiff