Allow capabilities to be added or removed from the allowed set for the daemon; e.g. default: CapPrm: 00000000880000df CapEff: 00000000880000df -o modcaps=+sys_admin CapPrm: 00000000882000df CapEff: 00000000882000df -o modcaps=+sys_admin:-chown CapPrm: 00000000882000de CapEff: 00000000882000de Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20200629115420.98443-4-dgilbert@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2970 lines
72 KiB
C
2970 lines
72 KiB
C
/*
|
|
* FUSE: Filesystem in Userspace
|
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* Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
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*
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* This program can be distributed under the terms of the GNU GPLv2.
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* See the file COPYING.
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*/
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|
|
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/*
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*
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* This file system mirrors the existing file system hierarchy of the
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* system, starting at the root file system. This is implemented by
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* just "passing through" all requests to the corresponding user-space
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* libc functions. In contrast to passthrough.c and passthrough_fh.c,
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* this implementation uses the low-level API. Its performance should
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* be the least bad among the three, but many operations are not
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* implemented. In particular, it is not possible to remove files (or
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* directories) because the code necessary to defer actual removal
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* until the file is not opened anymore would make the example much
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* more complicated.
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*
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* When writeback caching is enabled (-o writeback mount option), it
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* is only possible to write to files for which the mounting user has
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* read permissions. This is because the writeback cache requires the
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* kernel to be able to issue read requests for all files (which the
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* passthrough filesystem cannot satisfy if it can't read the file in
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* the underlying filesystem).
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*
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* Compile with:
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*
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* gcc -Wall passthrough_ll.c `pkg-config fuse3 --cflags --libs` -o
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* passthrough_ll
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*
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* ## Source code ##
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* \include passthrough_ll.c
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*/
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#include "qemu/osdep.h"
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#include "qemu/timer.h"
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#include "fuse_virtio.h"
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#include "fuse_log.h"
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#include "fuse_lowlevel.h"
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#include <assert.h>
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#include <cap-ng.h>
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#include <dirent.h>
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#include <errno.h>
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#include <glib.h>
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#include <inttypes.h>
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#include <limits.h>
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#include <pthread.h>
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#include <stdbool.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/file.h>
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#include <sys/mount.h>
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#include <sys/prctl.h>
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#include <sys/resource.h>
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#include <sys/syscall.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <sys/xattr.h>
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#include <syslog.h>
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#include <unistd.h>
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#include "passthrough_helpers.h"
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#include "seccomp.h"
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|
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|
/* Keep track of inode posix locks for each owner. */
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struct lo_inode_plock {
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uint64_t lock_owner;
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int fd; /* fd for OFD locks */
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};
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struct lo_map_elem {
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union {
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struct lo_inode *inode;
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struct lo_dirp *dirp;
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int fd;
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ssize_t freelist;
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};
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bool in_use;
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};
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/* Maps FUSE fh or ino values to internal objects */
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struct lo_map {
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struct lo_map_elem *elems;
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size_t nelems;
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ssize_t freelist;
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};
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struct lo_key {
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ino_t ino;
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dev_t dev;
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};
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|
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struct lo_inode {
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int fd;
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|
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/*
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* Atomic reference count for this object. The nlookup field holds a
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* reference and release it when nlookup reaches 0.
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*/
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gint refcount;
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|
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|
struct lo_key key;
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|
|
|
/*
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* This counter keeps the inode alive during the FUSE session.
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|
* Incremented when the FUSE inode number is sent in a reply
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* (FUSE_LOOKUP, FUSE_READDIRPLUS, etc). Decremented when an inode is
|
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* released by requests like FUSE_FORGET, FUSE_RMDIR, FUSE_RENAME, etc.
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*
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* Note that this value is untrusted because the client can manipulate
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* it arbitrarily using FUSE_FORGET requests.
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*
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* Protected by lo->mutex.
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|
*/
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uint64_t nlookup;
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|
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fuse_ino_t fuse_ino;
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pthread_mutex_t plock_mutex;
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GHashTable *posix_locks; /* protected by lo_inode->plock_mutex */
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|
|
|
mode_t filetype;
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};
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struct lo_cred {
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uid_t euid;
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gid_t egid;
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};
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|
enum {
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CACHE_NONE,
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CACHE_AUTO,
|
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CACHE_ALWAYS,
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};
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|
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|
struct lo_data {
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pthread_mutex_t mutex;
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int debug;
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int writeback;
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int flock;
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int posix_lock;
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int xattr;
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char *source;
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char *modcaps;
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double timeout;
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int cache;
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int timeout_set;
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int readdirplus_set;
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int readdirplus_clear;
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struct lo_inode root;
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GHashTable *inodes; /* protected by lo->mutex */
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struct lo_map ino_map; /* protected by lo->mutex */
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struct lo_map dirp_map; /* protected by lo->mutex */
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struct lo_map fd_map; /* protected by lo->mutex */
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/* An O_PATH file descriptor to /proc/self/fd/ */
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int proc_self_fd;
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};
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static const struct fuse_opt lo_opts[] = {
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{ "writeback", offsetof(struct lo_data, writeback), 1 },
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{ "no_writeback", offsetof(struct lo_data, writeback), 0 },
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{ "source=%s", offsetof(struct lo_data, source), 0 },
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{ "flock", offsetof(struct lo_data, flock), 1 },
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{ "no_flock", offsetof(struct lo_data, flock), 0 },
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{ "posix_lock", offsetof(struct lo_data, posix_lock), 1 },
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{ "no_posix_lock", offsetof(struct lo_data, posix_lock), 0 },
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{ "xattr", offsetof(struct lo_data, xattr), 1 },
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{ "no_xattr", offsetof(struct lo_data, xattr), 0 },
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{ "modcaps=%s", offsetof(struct lo_data, modcaps), 0 },
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{ "timeout=%lf", offsetof(struct lo_data, timeout), 0 },
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{ "timeout=", offsetof(struct lo_data, timeout_set), 1 },
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{ "cache=none", offsetof(struct lo_data, cache), CACHE_NONE },
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{ "cache=auto", offsetof(struct lo_data, cache), CACHE_AUTO },
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{ "cache=always", offsetof(struct lo_data, cache), CACHE_ALWAYS },
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{ "readdirplus", offsetof(struct lo_data, readdirplus_set), 1 },
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{ "no_readdirplus", offsetof(struct lo_data, readdirplus_clear), 1 },
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FUSE_OPT_END
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};
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static bool use_syslog = false;
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static int current_log_level;
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static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode *inode,
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uint64_t n);
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static struct {
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pthread_mutex_t mutex;
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void *saved;
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} cap;
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/* That we loaded cap-ng in the current thread from the saved */
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static __thread bool cap_loaded = 0;
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static struct lo_inode *lo_find(struct lo_data *lo, struct stat *st);
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static int is_dot_or_dotdot(const char *name)
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{
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return name[0] == '.' &&
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(name[1] == '\0' || (name[1] == '.' && name[2] == '\0'));
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}
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/* Is `path` a single path component that is not "." or ".."? */
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static int is_safe_path_component(const char *path)
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{
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if (strchr(path, '/')) {
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return 0;
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}
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return !is_dot_or_dotdot(path);
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}
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static struct lo_data *lo_data(fuse_req_t req)
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{
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return (struct lo_data *)fuse_req_userdata(req);
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}
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/*
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* Load capng's state from our saved state if the current thread
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* hadn't previously been loaded.
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* returns 0 on success
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*/
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static int load_capng(void)
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{
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if (!cap_loaded) {
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pthread_mutex_lock(&cap.mutex);
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capng_restore_state(&cap.saved);
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/*
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* restore_state free's the saved copy
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* so make another.
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*/
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cap.saved = capng_save_state();
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if (!cap.saved) {
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pthread_mutex_unlock(&cap.mutex);
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fuse_log(FUSE_LOG_ERR, "capng_save_state (thread)\n");
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return -EINVAL;
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}
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pthread_mutex_unlock(&cap.mutex);
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/*
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* We want to use the loaded state for our pid,
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* not the original
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*/
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capng_setpid(syscall(SYS_gettid));
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cap_loaded = true;
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}
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return 0;
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}
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/*
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* Helpers for dropping and regaining effective capabilities. Returns 0
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* on success, error otherwise
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*/
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static int drop_effective_cap(const char *cap_name, bool *cap_dropped)
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{
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int cap, ret;
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cap = capng_name_to_capability(cap_name);
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if (cap < 0) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "capng_name_to_capability(%s) failed:%s\n",
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cap_name, strerror(errno));
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goto out;
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}
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if (load_capng()) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "load_capng() failed\n");
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goto out;
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}
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/* We dont have this capability in effective set already. */
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if (!capng_have_capability(CAPNG_EFFECTIVE, cap)) {
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ret = 0;
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goto out;
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}
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if (capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, cap)) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "capng_update(DROP,) failed\n");
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goto out;
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}
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if (capng_apply(CAPNG_SELECT_CAPS)) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "drop:capng_apply() failed\n");
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goto out;
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}
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ret = 0;
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if (cap_dropped) {
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*cap_dropped = true;
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}
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out:
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return ret;
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}
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static int gain_effective_cap(const char *cap_name)
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{
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int cap;
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int ret = 0;
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cap = capng_name_to_capability(cap_name);
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if (cap < 0) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "capng_name_to_capability(%s) failed:%s\n",
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cap_name, strerror(errno));
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goto out;
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}
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if (load_capng()) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "load_capng() failed\n");
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goto out;
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}
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|
|
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if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, cap)) {
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ret = errno;
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fuse_log(FUSE_LOG_ERR, "capng_update(ADD,) failed\n");
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goto out;
|
|
}
|
|
|
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if (capng_apply(CAPNG_SELECT_CAPS)) {
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ret = errno;
|
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fuse_log(FUSE_LOG_ERR, "gain:capng_apply() failed\n");
|
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goto out;
|
|
}
|
|
ret = 0;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static void lo_map_init(struct lo_map *map)
|
|
{
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|
map->elems = NULL;
|
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map->nelems = 0;
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map->freelist = -1;
|
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}
|
|
|
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static void lo_map_destroy(struct lo_map *map)
|
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{
|
|
free(map->elems);
|
|
}
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|
|
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static int lo_map_grow(struct lo_map *map, size_t new_nelems)
|
|
{
|
|
struct lo_map_elem *new_elems;
|
|
size_t i;
|
|
|
|
if (new_nelems <= map->nelems) {
|
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return 1;
|
|
}
|
|
|
|
new_elems = realloc(map->elems, sizeof(map->elems[0]) * new_nelems);
|
|
if (!new_elems) {
|
|
return 0;
|
|
}
|
|
|
|
for (i = map->nelems; i < new_nelems; i++) {
|
|
new_elems[i].freelist = i + 1;
|
|
new_elems[i].in_use = false;
|
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}
|
|
new_elems[new_nelems - 1].freelist = -1;
|
|
|
|
map->elems = new_elems;
|
|
map->freelist = map->nelems;
|
|
map->nelems = new_nelems;
|
|
return 1;
|
|
}
|
|
|
|
static struct lo_map_elem *lo_map_alloc_elem(struct lo_map *map)
|
|
{
|
|
struct lo_map_elem *elem;
|
|
|
|
if (map->freelist == -1 && !lo_map_grow(map, map->nelems + 256)) {
|
|
return NULL;
|
|
}
|
|
|
|
elem = &map->elems[map->freelist];
|
|
map->freelist = elem->freelist;
|
|
|
|
elem->in_use = true;
|
|
|
|
return elem;
|
|
}
|
|
|
|
static struct lo_map_elem *lo_map_reserve(struct lo_map *map, size_t key)
|
|
{
|
|
ssize_t *prev;
|
|
|
|
if (!lo_map_grow(map, key + 1)) {
|
|
return NULL;
|
|
}
|
|
|
|
for (prev = &map->freelist; *prev != -1;
|
|
prev = &map->elems[*prev].freelist) {
|
|
if (*prev == key) {
|
|
struct lo_map_elem *elem = &map->elems[key];
|
|
|
|
*prev = elem->freelist;
|
|
elem->in_use = true;
|
|
return elem;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static struct lo_map_elem *lo_map_get(struct lo_map *map, size_t key)
|
|
{
|
|
if (key >= map->nelems) {
|
|
return NULL;
|
|
}
|
|
if (!map->elems[key].in_use) {
|
|
return NULL;
|
|
}
|
|
return &map->elems[key];
|
|
}
|
|
|
|
static void lo_map_remove(struct lo_map *map, size_t key)
|
|
{
|
|
struct lo_map_elem *elem;
|
|
|
|
if (key >= map->nelems) {
|
|
return;
|
|
}
|
|
|
|
elem = &map->elems[key];
|
|
if (!elem->in_use) {
|
|
return;
|
|
}
|
|
|
|
elem->in_use = false;
|
|
|
|
elem->freelist = map->freelist;
|
|
map->freelist = key;
|
|
}
|
|
|
|
/* Assumes lo->mutex is held */
|
|
static ssize_t lo_add_fd_mapping(fuse_req_t req, int fd)
|
|
{
|
|
struct lo_map_elem *elem;
|
|
|
|
elem = lo_map_alloc_elem(&lo_data(req)->fd_map);
|
|
if (!elem) {
|
|
return -1;
|
|
}
|
|
|
|
elem->fd = fd;
|
|
return elem - lo_data(req)->fd_map.elems;
|
|
}
|
|
|
|
/* Assumes lo->mutex is held */
|
|
static ssize_t lo_add_dirp_mapping(fuse_req_t req, struct lo_dirp *dirp)
|
|
{
|
|
struct lo_map_elem *elem;
|
|
|
|
elem = lo_map_alloc_elem(&lo_data(req)->dirp_map);
|
|
if (!elem) {
|
|
return -1;
|
|
}
|
|
|
|
elem->dirp = dirp;
|
|
return elem - lo_data(req)->dirp_map.elems;
|
|
}
|
|
|
|
/* Assumes lo->mutex is held */
|
|
static ssize_t lo_add_inode_mapping(fuse_req_t req, struct lo_inode *inode)
|
|
{
|
|
struct lo_map_elem *elem;
|
|
|
|
elem = lo_map_alloc_elem(&lo_data(req)->ino_map);
|
|
if (!elem) {
|
|
return -1;
|
|
}
|
|
|
|
elem->inode = inode;
|
|
return elem - lo_data(req)->ino_map.elems;
|
|
}
|
|
|
|
static void lo_inode_put(struct lo_data *lo, struct lo_inode **inodep)
|
|
{
|
|
struct lo_inode *inode = *inodep;
|
|
|
|
if (!inode) {
|
|
return;
|
|
}
|
|
|
|
*inodep = NULL;
|
|
|
|
if (g_atomic_int_dec_and_test(&inode->refcount)) {
|
|
close(inode->fd);
|
|
free(inode);
|
|
}
|
|
}
|
|
|
|
/* Caller must release refcount using lo_inode_put() */
|
|
static struct lo_inode *lo_inode(fuse_req_t req, fuse_ino_t ino)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_map_elem *elem;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
elem = lo_map_get(&lo->ino_map, ino);
|
|
if (elem) {
|
|
g_atomic_int_inc(&elem->inode->refcount);
|
|
}
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
if (!elem) {
|
|
return NULL;
|
|
}
|
|
|
|
return elem->inode;
|
|
}
|
|
|
|
/*
|
|
* TODO Remove this helper and force callers to hold an inode refcount until
|
|
* they are done with the fd. This will be done in a later patch to make
|
|
* review easier.
|
|
*/
|
|
static int lo_fd(fuse_req_t req, fuse_ino_t ino)
|
|
{
|
|
struct lo_inode *inode = lo_inode(req, ino);
|
|
int fd;
|
|
|
|
if (!inode) {
|
|
return -1;
|
|
}
|
|
|
|
fd = inode->fd;
|
|
lo_inode_put(lo_data(req), &inode);
|
|
return fd;
|
|
}
|
|
|
|
static void lo_init(void *userdata, struct fuse_conn_info *conn)
|
|
{
|
|
struct lo_data *lo = (struct lo_data *)userdata;
|
|
|
|
if (conn->capable & FUSE_CAP_EXPORT_SUPPORT) {
|
|
conn->want |= FUSE_CAP_EXPORT_SUPPORT;
|
|
}
|
|
|
|
if (lo->writeback && conn->capable & FUSE_CAP_WRITEBACK_CACHE) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: activating writeback\n");
|
|
conn->want |= FUSE_CAP_WRITEBACK_CACHE;
|
|
}
|
|
if (conn->capable & FUSE_CAP_FLOCK_LOCKS) {
|
|
if (lo->flock) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: activating flock locks\n");
|
|
conn->want |= FUSE_CAP_FLOCK_LOCKS;
|
|
} else {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling flock locks\n");
|
|
conn->want &= ~FUSE_CAP_FLOCK_LOCKS;
|
|
}
|
|
}
|
|
|
|
if (conn->capable & FUSE_CAP_POSIX_LOCKS) {
|
|
if (lo->posix_lock) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: activating posix locks\n");
|
|
conn->want |= FUSE_CAP_POSIX_LOCKS;
|
|
} else {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling posix locks\n");
|
|
conn->want &= ~FUSE_CAP_POSIX_LOCKS;
|
|
}
|
|
}
|
|
|
|
if ((lo->cache == CACHE_NONE && !lo->readdirplus_set) ||
|
|
lo->readdirplus_clear) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling readdirplus\n");
|
|
conn->want &= ~FUSE_CAP_READDIRPLUS;
|
|
}
|
|
}
|
|
|
|
static void lo_getattr(fuse_req_t req, fuse_ino_t ino,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
int res;
|
|
struct stat buf;
|
|
struct lo_data *lo = lo_data(req);
|
|
|
|
(void)fi;
|
|
|
|
res =
|
|
fstatat(lo_fd(req, ino), "", &buf, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
return (void)fuse_reply_err(req, errno);
|
|
}
|
|
|
|
fuse_reply_attr(req, &buf, lo->timeout);
|
|
}
|
|
|
|
static int lo_fi_fd(fuse_req_t req, struct fuse_file_info *fi)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_map_elem *elem;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
elem = lo_map_get(&lo->fd_map, fi->fh);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
if (!elem) {
|
|
return -1;
|
|
}
|
|
|
|
return elem->fd;
|
|
}
|
|
|
|
static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
|
|
int valid, struct fuse_file_info *fi)
|
|
{
|
|
int saverr;
|
|
char procname[64];
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode;
|
|
int ifd;
|
|
int res;
|
|
int fd;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
ifd = inode->fd;
|
|
|
|
/* If fi->fh is invalid we'll report EBADF later */
|
|
if (fi) {
|
|
fd = lo_fi_fd(req, fi);
|
|
}
|
|
|
|
if (valid & FUSE_SET_ATTR_MODE) {
|
|
if (fi) {
|
|
res = fchmod(fd, attr->st_mode);
|
|
} else {
|
|
sprintf(procname, "%i", ifd);
|
|
res = fchmodat(lo->proc_self_fd, procname, attr->st_mode, 0);
|
|
}
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
if (valid & (FUSE_SET_ATTR_UID | FUSE_SET_ATTR_GID)) {
|
|
uid_t uid = (valid & FUSE_SET_ATTR_UID) ? attr->st_uid : (uid_t)-1;
|
|
gid_t gid = (valid & FUSE_SET_ATTR_GID) ? attr->st_gid : (gid_t)-1;
|
|
|
|
res = fchownat(ifd, "", uid, gid, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
if (valid & FUSE_SET_ATTR_SIZE) {
|
|
int truncfd;
|
|
|
|
if (fi) {
|
|
truncfd = fd;
|
|
} else {
|
|
sprintf(procname, "%i", ifd);
|
|
truncfd = openat(lo->proc_self_fd, procname, O_RDWR);
|
|
if (truncfd < 0) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
res = ftruncate(truncfd, attr->st_size);
|
|
if (!fi) {
|
|
saverr = errno;
|
|
close(truncfd);
|
|
errno = saverr;
|
|
}
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
if (valid & (FUSE_SET_ATTR_ATIME | FUSE_SET_ATTR_MTIME)) {
|
|
struct timespec tv[2];
|
|
|
|
tv[0].tv_sec = 0;
|
|
tv[1].tv_sec = 0;
|
|
tv[0].tv_nsec = UTIME_OMIT;
|
|
tv[1].tv_nsec = UTIME_OMIT;
|
|
|
|
if (valid & FUSE_SET_ATTR_ATIME_NOW) {
|
|
tv[0].tv_nsec = UTIME_NOW;
|
|
} else if (valid & FUSE_SET_ATTR_ATIME) {
|
|
tv[0] = attr->st_atim;
|
|
}
|
|
|
|
if (valid & FUSE_SET_ATTR_MTIME_NOW) {
|
|
tv[1].tv_nsec = UTIME_NOW;
|
|
} else if (valid & FUSE_SET_ATTR_MTIME) {
|
|
tv[1] = attr->st_mtim;
|
|
}
|
|
|
|
if (fi) {
|
|
res = futimens(fd, tv);
|
|
} else {
|
|
sprintf(procname, "%i", inode->fd);
|
|
res = utimensat(lo->proc_self_fd, procname, tv, 0);
|
|
}
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
lo_inode_put(lo, &inode);
|
|
|
|
return lo_getattr(req, ino, fi);
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
lo_inode_put(lo, &inode);
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
static struct lo_inode *lo_find(struct lo_data *lo, struct stat *st)
|
|
{
|
|
struct lo_inode *p;
|
|
struct lo_key key = {
|
|
.ino = st->st_ino,
|
|
.dev = st->st_dev,
|
|
};
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
p = g_hash_table_lookup(lo->inodes, &key);
|
|
if (p) {
|
|
assert(p->nlookup > 0);
|
|
p->nlookup++;
|
|
g_atomic_int_inc(&p->refcount);
|
|
}
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
return p;
|
|
}
|
|
|
|
/* value_destroy_func for posix_locks GHashTable */
|
|
static void posix_locks_value_destroy(gpointer data)
|
|
{
|
|
struct lo_inode_plock *plock = data;
|
|
|
|
/*
|
|
* We had used open() for locks and had only one fd. So
|
|
* closing this fd should release all OFD locks.
|
|
*/
|
|
close(plock->fd);
|
|
free(plock);
|
|
}
|
|
|
|
/*
|
|
* Increments nlookup and caller must release refcount using
|
|
* lo_inode_put(&parent).
|
|
*/
|
|
static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
|
|
struct fuse_entry_param *e)
|
|
{
|
|
int newfd;
|
|
int res;
|
|
int saverr;
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode = NULL;
|
|
struct lo_inode *dir = lo_inode(req, parent);
|
|
|
|
/*
|
|
* name_to_handle_at() and open_by_handle_at() can reach here with fuse
|
|
* mount point in guest, but we don't have its inode info in the
|
|
* ino_map.
|
|
*/
|
|
if (!dir) {
|
|
return ENOENT;
|
|
}
|
|
|
|
memset(e, 0, sizeof(*e));
|
|
e->attr_timeout = lo->timeout;
|
|
e->entry_timeout = lo->timeout;
|
|
|
|
/* Do not allow escaping root directory */
|
|
if (dir == &lo->root && strcmp(name, "..") == 0) {
|
|
name = ".";
|
|
}
|
|
|
|
newfd = openat(dir->fd, name, O_PATH | O_NOFOLLOW);
|
|
if (newfd == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
res = fstatat(newfd, "", &e->attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
inode = lo_find(lo, &e->attr);
|
|
if (inode) {
|
|
close(newfd);
|
|
} else {
|
|
inode = calloc(1, sizeof(struct lo_inode));
|
|
if (!inode) {
|
|
goto out_err;
|
|
}
|
|
|
|
/* cache only filetype */
|
|
inode->filetype = (e->attr.st_mode & S_IFMT);
|
|
|
|
/*
|
|
* One for the caller and one for nlookup (released in
|
|
* unref_inode_lolocked())
|
|
*/
|
|
g_atomic_int_set(&inode->refcount, 2);
|
|
|
|
inode->nlookup = 1;
|
|
inode->fd = newfd;
|
|
inode->key.ino = e->attr.st_ino;
|
|
inode->key.dev = e->attr.st_dev;
|
|
pthread_mutex_init(&inode->plock_mutex, NULL);
|
|
inode->posix_locks = g_hash_table_new_full(
|
|
g_direct_hash, g_direct_equal, NULL, posix_locks_value_destroy);
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
inode->fuse_ino = lo_add_inode_mapping(req, inode);
|
|
g_hash_table_insert(lo->inodes, &inode->key, inode);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
}
|
|
e->ino = inode->fuse_ino;
|
|
lo_inode_put(lo, &inode);
|
|
lo_inode_put(lo, &dir);
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n", (unsigned long long)parent,
|
|
name, (unsigned long long)e->ino);
|
|
|
|
return 0;
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
if (newfd != -1) {
|
|
close(newfd);
|
|
}
|
|
lo_inode_put(lo, &inode);
|
|
lo_inode_put(lo, &dir);
|
|
return saverr;
|
|
}
|
|
|
|
static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
|
|
{
|
|
struct fuse_entry_param e;
|
|
int err;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_lookup(parent=%" PRIu64 ", name=%s)\n", parent,
|
|
name);
|
|
|
|
/*
|
|
* Don't use is_safe_path_component(), allow "." and ".." for NFS export
|
|
* support.
|
|
*/
|
|
if (strchr(name, '/')) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
err = lo_do_lookup(req, parent, name, &e);
|
|
if (err) {
|
|
fuse_reply_err(req, err);
|
|
} else {
|
|
fuse_reply_entry(req, &e);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* On some archs, setres*id is limited to 2^16 but they
|
|
* provide setres*id32 variants that allow 2^32.
|
|
* Others just let setres*id do 2^32 anyway.
|
|
*/
|
|
#ifdef SYS_setresgid32
|
|
#define OURSYS_setresgid SYS_setresgid32
|
|
#else
|
|
#define OURSYS_setresgid SYS_setresgid
|
|
#endif
|
|
|
|
#ifdef SYS_setresuid32
|
|
#define OURSYS_setresuid SYS_setresuid32
|
|
#else
|
|
#define OURSYS_setresuid SYS_setresuid
|
|
#endif
|
|
|
|
/*
|
|
* Change to uid/gid of caller so that file is created with
|
|
* ownership of caller.
|
|
* TODO: What about selinux context?
|
|
*/
|
|
static int lo_change_cred(fuse_req_t req, struct lo_cred *old)
|
|
{
|
|
int res;
|
|
|
|
old->euid = geteuid();
|
|
old->egid = getegid();
|
|
|
|
res = syscall(OURSYS_setresgid, -1, fuse_req_ctx(req)->gid, -1);
|
|
if (res == -1) {
|
|
return errno;
|
|
}
|
|
|
|
res = syscall(OURSYS_setresuid, -1, fuse_req_ctx(req)->uid, -1);
|
|
if (res == -1) {
|
|
int errno_save = errno;
|
|
|
|
syscall(OURSYS_setresgid, -1, old->egid, -1);
|
|
return errno_save;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Regain Privileges */
|
|
static void lo_restore_cred(struct lo_cred *old)
|
|
{
|
|
int res;
|
|
|
|
res = syscall(OURSYS_setresuid, -1, old->euid, -1);
|
|
if (res == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "seteuid(%u): %m\n", old->euid);
|
|
exit(1);
|
|
}
|
|
|
|
res = syscall(OURSYS_setresgid, -1, old->egid, -1);
|
|
if (res == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "setegid(%u): %m\n", old->egid);
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent,
|
|
const char *name, mode_t mode, dev_t rdev,
|
|
const char *link)
|
|
{
|
|
int res;
|
|
int saverr;
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *dir;
|
|
struct fuse_entry_param e;
|
|
struct lo_cred old = {};
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
dir = lo_inode(req, parent);
|
|
if (!dir) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = lo_change_cred(req, &old);
|
|
if (saverr) {
|
|
goto out;
|
|
}
|
|
|
|
res = mknod_wrapper(dir->fd, name, link, mode, rdev);
|
|
|
|
saverr = errno;
|
|
|
|
lo_restore_cred(&old);
|
|
|
|
if (res == -1) {
|
|
goto out;
|
|
}
|
|
|
|
saverr = lo_do_lookup(req, parent, name, &e);
|
|
if (saverr) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n", (unsigned long long)parent,
|
|
name, (unsigned long long)e.ino);
|
|
|
|
fuse_reply_entry(req, &e);
|
|
lo_inode_put(lo, &dir);
|
|
return;
|
|
|
|
out:
|
|
lo_inode_put(lo, &dir);
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
static void lo_mknod(fuse_req_t req, fuse_ino_t parent, const char *name,
|
|
mode_t mode, dev_t rdev)
|
|
{
|
|
lo_mknod_symlink(req, parent, name, mode, rdev, NULL);
|
|
}
|
|
|
|
static void lo_mkdir(fuse_req_t req, fuse_ino_t parent, const char *name,
|
|
mode_t mode)
|
|
{
|
|
lo_mknod_symlink(req, parent, name, S_IFDIR | mode, 0, NULL);
|
|
}
|
|
|
|
static void lo_symlink(fuse_req_t req, const char *link, fuse_ino_t parent,
|
|
const char *name)
|
|
{
|
|
lo_mknod_symlink(req, parent, name, S_IFLNK, 0, link);
|
|
}
|
|
|
|
static void lo_link(fuse_req_t req, fuse_ino_t ino, fuse_ino_t parent,
|
|
const char *name)
|
|
{
|
|
int res;
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *parent_inode;
|
|
struct lo_inode *inode;
|
|
struct fuse_entry_param e;
|
|
char procname[64];
|
|
int saverr;
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
parent_inode = lo_inode(req, parent);
|
|
inode = lo_inode(req, ino);
|
|
if (!parent_inode || !inode) {
|
|
errno = EBADF;
|
|
goto out_err;
|
|
}
|
|
|
|
memset(&e, 0, sizeof(struct fuse_entry_param));
|
|
e.attr_timeout = lo->timeout;
|
|
e.entry_timeout = lo->timeout;
|
|
|
|
sprintf(procname, "%i", inode->fd);
|
|
res = linkat(lo->proc_self_fd, procname, parent_inode->fd, name,
|
|
AT_SYMLINK_FOLLOW);
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
res = fstatat(inode->fd, "", &e.attr, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
inode->nlookup++;
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
e.ino = inode->fuse_ino;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n", (unsigned long long)parent,
|
|
name, (unsigned long long)e.ino);
|
|
|
|
fuse_reply_entry(req, &e);
|
|
lo_inode_put(lo, &parent_inode);
|
|
lo_inode_put(lo, &inode);
|
|
return;
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
lo_inode_put(lo, &parent_inode);
|
|
lo_inode_put(lo, &inode);
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
/* Increments nlookup and caller must release refcount using lo_inode_put() */
|
|
static struct lo_inode *lookup_name(fuse_req_t req, fuse_ino_t parent,
|
|
const char *name)
|
|
{
|
|
int res;
|
|
struct stat attr;
|
|
|
|
res = fstatat(lo_fd(req, parent), name, &attr,
|
|
AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
return NULL;
|
|
}
|
|
|
|
return lo_find(lo_data(req), &attr);
|
|
}
|
|
|
|
static void lo_rmdir(fuse_req_t req, fuse_ino_t parent, const char *name)
|
|
{
|
|
int res;
|
|
struct lo_inode *inode;
|
|
struct lo_data *lo = lo_data(req);
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
inode = lookup_name(req, parent, name);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EIO);
|
|
return;
|
|
}
|
|
|
|
res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
unref_inode_lolocked(lo, inode, 1);
|
|
lo_inode_put(lo, &inode);
|
|
}
|
|
|
|
static void lo_rename(fuse_req_t req, fuse_ino_t parent, const char *name,
|
|
fuse_ino_t newparent, const char *newname,
|
|
unsigned int flags)
|
|
{
|
|
int res;
|
|
struct lo_inode *parent_inode;
|
|
struct lo_inode *newparent_inode;
|
|
struct lo_inode *oldinode = NULL;
|
|
struct lo_inode *newinode = NULL;
|
|
struct lo_data *lo = lo_data(req);
|
|
|
|
if (!is_safe_path_component(name) || !is_safe_path_component(newname)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
parent_inode = lo_inode(req, parent);
|
|
newparent_inode = lo_inode(req, newparent);
|
|
if (!parent_inode || !newparent_inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
goto out;
|
|
}
|
|
|
|
oldinode = lookup_name(req, parent, name);
|
|
newinode = lookup_name(req, newparent, newname);
|
|
|
|
if (!oldinode) {
|
|
fuse_reply_err(req, EIO);
|
|
goto out;
|
|
}
|
|
|
|
if (flags) {
|
|
#ifndef SYS_renameat2
|
|
fuse_reply_err(req, EINVAL);
|
|
#else
|
|
res = syscall(SYS_renameat2, parent_inode->fd, name,
|
|
newparent_inode->fd, newname, flags);
|
|
if (res == -1 && errno == ENOSYS) {
|
|
fuse_reply_err(req, EINVAL);
|
|
} else {
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
#endif
|
|
goto out;
|
|
}
|
|
|
|
res = renameat(parent_inode->fd, name, newparent_inode->fd, newname);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
out:
|
|
unref_inode_lolocked(lo, oldinode, 1);
|
|
unref_inode_lolocked(lo, newinode, 1);
|
|
lo_inode_put(lo, &oldinode);
|
|
lo_inode_put(lo, &newinode);
|
|
lo_inode_put(lo, &parent_inode);
|
|
lo_inode_put(lo, &newparent_inode);
|
|
}
|
|
|
|
static void lo_unlink(fuse_req_t req, fuse_ino_t parent, const char *name)
|
|
{
|
|
int res;
|
|
struct lo_inode *inode;
|
|
struct lo_data *lo = lo_data(req);
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
inode = lookup_name(req, parent, name);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EIO);
|
|
return;
|
|
}
|
|
|
|
res = unlinkat(lo_fd(req, parent), name, 0);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
unref_inode_lolocked(lo, inode, 1);
|
|
lo_inode_put(lo, &inode);
|
|
}
|
|
|
|
/* To be called with lo->mutex held */
|
|
static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n)
|
|
{
|
|
if (!inode) {
|
|
return;
|
|
}
|
|
|
|
assert(inode->nlookup >= n);
|
|
inode->nlookup -= n;
|
|
if (!inode->nlookup) {
|
|
lo_map_remove(&lo->ino_map, inode->fuse_ino);
|
|
g_hash_table_remove(lo->inodes, &inode->key);
|
|
if (g_hash_table_size(inode->posix_locks)) {
|
|
fuse_log(FUSE_LOG_WARNING, "Hash table is not empty\n");
|
|
}
|
|
g_hash_table_destroy(inode->posix_locks);
|
|
pthread_mutex_destroy(&inode->plock_mutex);
|
|
|
|
/* Drop our refcount from lo_do_lookup() */
|
|
lo_inode_put(lo, &inode);
|
|
}
|
|
}
|
|
|
|
static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode *inode,
|
|
uint64_t n)
|
|
{
|
|
if (!inode) {
|
|
return;
|
|
}
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
unref_inode(lo, inode, n);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
}
|
|
|
|
static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
return;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, " forget %lli %lli -%lli\n",
|
|
(unsigned long long)ino, (unsigned long long)inode->nlookup,
|
|
(unsigned long long)nlookup);
|
|
|
|
unref_inode_lolocked(lo, inode, nlookup);
|
|
lo_inode_put(lo, &inode);
|
|
}
|
|
|
|
static void lo_forget(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup)
|
|
{
|
|
lo_forget_one(req, ino, nlookup);
|
|
fuse_reply_none(req);
|
|
}
|
|
|
|
static void lo_forget_multi(fuse_req_t req, size_t count,
|
|
struct fuse_forget_data *forgets)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++) {
|
|
lo_forget_one(req, forgets[i].ino, forgets[i].nlookup);
|
|
}
|
|
fuse_reply_none(req);
|
|
}
|
|
|
|
static void lo_readlink(fuse_req_t req, fuse_ino_t ino)
|
|
{
|
|
char buf[PATH_MAX + 1];
|
|
int res;
|
|
|
|
res = readlinkat(lo_fd(req, ino), "", buf, sizeof(buf));
|
|
if (res == -1) {
|
|
return (void)fuse_reply_err(req, errno);
|
|
}
|
|
|
|
if (res == sizeof(buf)) {
|
|
return (void)fuse_reply_err(req, ENAMETOOLONG);
|
|
}
|
|
|
|
buf[res] = '\0';
|
|
|
|
fuse_reply_readlink(req, buf);
|
|
}
|
|
|
|
struct lo_dirp {
|
|
gint refcount;
|
|
DIR *dp;
|
|
struct dirent *entry;
|
|
off_t offset;
|
|
};
|
|
|
|
static void lo_dirp_put(struct lo_dirp **dp)
|
|
{
|
|
struct lo_dirp *d = *dp;
|
|
|
|
if (!d) {
|
|
return;
|
|
}
|
|
*dp = NULL;
|
|
|
|
if (g_atomic_int_dec_and_test(&d->refcount)) {
|
|
closedir(d->dp);
|
|
free(d);
|
|
}
|
|
}
|
|
|
|
/* Call lo_dirp_put() on the return value when no longer needed */
|
|
static struct lo_dirp *lo_dirp(fuse_req_t req, struct fuse_file_info *fi)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_map_elem *elem;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
elem = lo_map_get(&lo->dirp_map, fi->fh);
|
|
if (elem) {
|
|
g_atomic_int_inc(&elem->dirp->refcount);
|
|
}
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
if (!elem) {
|
|
return NULL;
|
|
}
|
|
|
|
return elem->dirp;
|
|
}
|
|
|
|
static void lo_opendir(fuse_req_t req, fuse_ino_t ino,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
int error = ENOMEM;
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_dirp *d;
|
|
int fd;
|
|
ssize_t fh;
|
|
|
|
d = calloc(1, sizeof(struct lo_dirp));
|
|
if (d == NULL) {
|
|
goto out_err;
|
|
}
|
|
|
|
fd = openat(lo_fd(req, ino), ".", O_RDONLY);
|
|
if (fd == -1) {
|
|
goto out_errno;
|
|
}
|
|
|
|
d->dp = fdopendir(fd);
|
|
if (d->dp == NULL) {
|
|
goto out_errno;
|
|
}
|
|
|
|
d->offset = 0;
|
|
d->entry = NULL;
|
|
|
|
g_atomic_int_set(&d->refcount, 1); /* paired with lo_releasedir() */
|
|
pthread_mutex_lock(&lo->mutex);
|
|
fh = lo_add_dirp_mapping(req, d);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
if (fh == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
fi->fh = fh;
|
|
if (lo->cache == CACHE_ALWAYS) {
|
|
fi->cache_readdir = 1;
|
|
}
|
|
fuse_reply_open(req, fi);
|
|
return;
|
|
|
|
out_errno:
|
|
error = errno;
|
|
out_err:
|
|
if (d) {
|
|
if (d->dp) {
|
|
closedir(d->dp);
|
|
} else if (fd != -1) {
|
|
close(fd);
|
|
}
|
|
free(d);
|
|
}
|
|
fuse_reply_err(req, error);
|
|
}
|
|
|
|
static void lo_do_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
|
|
off_t offset, struct fuse_file_info *fi, int plus)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_dirp *d = NULL;
|
|
struct lo_inode *dinode;
|
|
char *buf = NULL;
|
|
char *p;
|
|
size_t rem = size;
|
|
int err = EBADF;
|
|
|
|
dinode = lo_inode(req, ino);
|
|
if (!dinode) {
|
|
goto error;
|
|
}
|
|
|
|
d = lo_dirp(req, fi);
|
|
if (!d) {
|
|
goto error;
|
|
}
|
|
|
|
err = ENOMEM;
|
|
buf = calloc(1, size);
|
|
if (!buf) {
|
|
goto error;
|
|
}
|
|
p = buf;
|
|
|
|
if (offset != d->offset) {
|
|
seekdir(d->dp, offset);
|
|
d->entry = NULL;
|
|
d->offset = offset;
|
|
}
|
|
while (1) {
|
|
size_t entsize;
|
|
off_t nextoff;
|
|
const char *name;
|
|
|
|
if (!d->entry) {
|
|
errno = 0;
|
|
d->entry = readdir(d->dp);
|
|
if (!d->entry) {
|
|
if (errno) { /* Error */
|
|
err = errno;
|
|
goto error;
|
|
} else { /* End of stream */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
nextoff = d->entry->d_off;
|
|
name = d->entry->d_name;
|
|
|
|
fuse_ino_t entry_ino = 0;
|
|
struct fuse_entry_param e = (struct fuse_entry_param){
|
|
.attr.st_ino = d->entry->d_ino,
|
|
.attr.st_mode = d->entry->d_type << 12,
|
|
};
|
|
|
|
/* Hide root's parent directory */
|
|
if (dinode == &lo->root && strcmp(name, "..") == 0) {
|
|
e.attr.st_ino = lo->root.key.ino;
|
|
e.attr.st_mode = DT_DIR << 12;
|
|
}
|
|
|
|
if (plus) {
|
|
if (!is_dot_or_dotdot(name)) {
|
|
err = lo_do_lookup(req, ino, name, &e);
|
|
if (err) {
|
|
goto error;
|
|
}
|
|
entry_ino = e.ino;
|
|
}
|
|
|
|
entsize = fuse_add_direntry_plus(req, p, rem, name, &e, nextoff);
|
|
} else {
|
|
entsize = fuse_add_direntry(req, p, rem, name, &e.attr, nextoff);
|
|
}
|
|
if (entsize > rem) {
|
|
if (entry_ino != 0) {
|
|
lo_forget_one(req, entry_ino, 1);
|
|
}
|
|
break;
|
|
}
|
|
|
|
p += entsize;
|
|
rem -= entsize;
|
|
|
|
d->entry = NULL;
|
|
d->offset = nextoff;
|
|
}
|
|
|
|
err = 0;
|
|
error:
|
|
lo_dirp_put(&d);
|
|
lo_inode_put(lo, &dinode);
|
|
|
|
/*
|
|
* If there's an error, we can only signal it if we haven't stored
|
|
* any entries yet - otherwise we'd end up with wrong lookup
|
|
* counts for the entries that are already in the buffer. So we
|
|
* return what we've collected until that point.
|
|
*/
|
|
if (err && rem == size) {
|
|
fuse_reply_err(req, err);
|
|
} else {
|
|
fuse_reply_buf(req, buf, size - rem);
|
|
}
|
|
free(buf);
|
|
}
|
|
|
|
static void lo_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
|
|
off_t offset, struct fuse_file_info *fi)
|
|
{
|
|
lo_do_readdir(req, ino, size, offset, fi, 0);
|
|
}
|
|
|
|
static void lo_readdirplus(fuse_req_t req, fuse_ino_t ino, size_t size,
|
|
off_t offset, struct fuse_file_info *fi)
|
|
{
|
|
lo_do_readdir(req, ino, size, offset, fi, 1);
|
|
}
|
|
|
|
static void lo_releasedir(fuse_req_t req, fuse_ino_t ino,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_map_elem *elem;
|
|
struct lo_dirp *d;
|
|
|
|
(void)ino;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
elem = lo_map_get(&lo->dirp_map, fi->fh);
|
|
if (!elem) {
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
d = elem->dirp;
|
|
lo_map_remove(&lo->dirp_map, fi->fh);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
lo_dirp_put(&d); /* paired with lo_opendir() */
|
|
|
|
fuse_reply_err(req, 0);
|
|
}
|
|
|
|
static void update_open_flags(int writeback, struct fuse_file_info *fi)
|
|
{
|
|
/*
|
|
* With writeback cache, kernel may send read requests even
|
|
* when userspace opened write-only
|
|
*/
|
|
if (writeback && (fi->flags & O_ACCMODE) == O_WRONLY) {
|
|
fi->flags &= ~O_ACCMODE;
|
|
fi->flags |= O_RDWR;
|
|
}
|
|
|
|
/*
|
|
* With writeback cache, O_APPEND is handled by the kernel.
|
|
* This breaks atomicity (since the file may change in the
|
|
* underlying filesystem, so that the kernel's idea of the
|
|
* end of the file isn't accurate anymore). In this example,
|
|
* we just accept that. A more rigorous filesystem may want
|
|
* to return an error here
|
|
*/
|
|
if (writeback && (fi->flags & O_APPEND)) {
|
|
fi->flags &= ~O_APPEND;
|
|
}
|
|
|
|
/*
|
|
* O_DIRECT in guest should not necessarily mean bypassing page
|
|
* cache on host as well. If somebody needs that behavior, it
|
|
* probably should be a configuration knob in daemon.
|
|
*/
|
|
fi->flags &= ~O_DIRECT;
|
|
}
|
|
|
|
static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
|
|
mode_t mode, struct fuse_file_info *fi)
|
|
{
|
|
int fd;
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *parent_inode;
|
|
struct fuse_entry_param e;
|
|
int err;
|
|
struct lo_cred old = {};
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_create(parent=%" PRIu64 ", name=%s)\n", parent,
|
|
name);
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
parent_inode = lo_inode(req, parent);
|
|
if (!parent_inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
err = lo_change_cred(req, &old);
|
|
if (err) {
|
|
goto out;
|
|
}
|
|
|
|
update_open_flags(lo->writeback, fi);
|
|
|
|
fd = openat(parent_inode->fd, name, (fi->flags | O_CREAT) & ~O_NOFOLLOW,
|
|
mode);
|
|
err = fd == -1 ? errno : 0;
|
|
lo_restore_cred(&old);
|
|
|
|
if (!err) {
|
|
ssize_t fh;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
fh = lo_add_fd_mapping(req, fd);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
if (fh == -1) {
|
|
close(fd);
|
|
err = ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
fi->fh = fh;
|
|
err = lo_do_lookup(req, parent, name, &e);
|
|
}
|
|
if (lo->cache == CACHE_NONE) {
|
|
fi->direct_io = 1;
|
|
} else if (lo->cache == CACHE_ALWAYS) {
|
|
fi->keep_cache = 1;
|
|
}
|
|
|
|
out:
|
|
lo_inode_put(lo, &parent_inode);
|
|
|
|
if (err) {
|
|
fuse_reply_err(req, err);
|
|
} else {
|
|
fuse_reply_create(req, &e, fi);
|
|
}
|
|
}
|
|
|
|
/* Should be called with inode->plock_mutex held */
|
|
static struct lo_inode_plock *lookup_create_plock_ctx(struct lo_data *lo,
|
|
struct lo_inode *inode,
|
|
uint64_t lock_owner,
|
|
pid_t pid, int *err)
|
|
{
|
|
struct lo_inode_plock *plock;
|
|
char procname[64];
|
|
int fd;
|
|
|
|
plock =
|
|
g_hash_table_lookup(inode->posix_locks, GUINT_TO_POINTER(lock_owner));
|
|
|
|
if (plock) {
|
|
return plock;
|
|
}
|
|
|
|
plock = malloc(sizeof(struct lo_inode_plock));
|
|
if (!plock) {
|
|
*err = ENOMEM;
|
|
return NULL;
|
|
}
|
|
|
|
/* Open another instance of file which can be used for ofd locks. */
|
|
sprintf(procname, "%i", inode->fd);
|
|
|
|
/* TODO: What if file is not writable? */
|
|
fd = openat(lo->proc_self_fd, procname, O_RDWR);
|
|
if (fd == -1) {
|
|
*err = errno;
|
|
free(plock);
|
|
return NULL;
|
|
}
|
|
|
|
plock->lock_owner = lock_owner;
|
|
plock->fd = fd;
|
|
g_hash_table_insert(inode->posix_locks, GUINT_TO_POINTER(plock->lock_owner),
|
|
plock);
|
|
return plock;
|
|
}
|
|
|
|
static void lo_getlk(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi,
|
|
struct flock *lock)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode;
|
|
struct lo_inode_plock *plock;
|
|
int ret, saverr = 0;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_getlk(ino=%" PRIu64 ", flags=%d)"
|
|
" owner=0x%lx, l_type=%d l_start=0x%lx"
|
|
" l_len=0x%lx\n",
|
|
ino, fi->flags, fi->lock_owner, lock->l_type, lock->l_start,
|
|
lock->l_len);
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
pthread_mutex_lock(&inode->plock_mutex);
|
|
plock =
|
|
lookup_create_plock_ctx(lo, inode, fi->lock_owner, lock->l_pid, &ret);
|
|
if (!plock) {
|
|
saverr = ret;
|
|
goto out;
|
|
}
|
|
|
|
ret = fcntl(plock->fd, F_OFD_GETLK, lock);
|
|
if (ret == -1) {
|
|
saverr = errno;
|
|
}
|
|
|
|
out:
|
|
pthread_mutex_unlock(&inode->plock_mutex);
|
|
lo_inode_put(lo, &inode);
|
|
|
|
if (saverr) {
|
|
fuse_reply_err(req, saverr);
|
|
} else {
|
|
fuse_reply_lock(req, lock);
|
|
}
|
|
}
|
|
|
|
static void lo_setlk(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi,
|
|
struct flock *lock, int sleep)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode;
|
|
struct lo_inode_plock *plock;
|
|
int ret, saverr = 0;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_setlk(ino=%" PRIu64 ", flags=%d)"
|
|
" cmd=%d pid=%d owner=0x%lx sleep=%d l_whence=%d"
|
|
" l_start=0x%lx l_len=0x%lx\n",
|
|
ino, fi->flags, lock->l_type, lock->l_pid, fi->lock_owner, sleep,
|
|
lock->l_whence, lock->l_start, lock->l_len);
|
|
|
|
if (sleep) {
|
|
fuse_reply_err(req, EOPNOTSUPP);
|
|
return;
|
|
}
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
pthread_mutex_lock(&inode->plock_mutex);
|
|
plock =
|
|
lookup_create_plock_ctx(lo, inode, fi->lock_owner, lock->l_pid, &ret);
|
|
|
|
if (!plock) {
|
|
saverr = ret;
|
|
goto out;
|
|
}
|
|
|
|
/* TODO: Is it alright to modify flock? */
|
|
lock->l_pid = 0;
|
|
ret = fcntl(plock->fd, F_OFD_SETLK, lock);
|
|
if (ret == -1) {
|
|
saverr = errno;
|
|
}
|
|
|
|
out:
|
|
pthread_mutex_unlock(&inode->plock_mutex);
|
|
lo_inode_put(lo, &inode);
|
|
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
static void lo_fsyncdir(fuse_req_t req, fuse_ino_t ino, int datasync,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
int res;
|
|
struct lo_dirp *d;
|
|
int fd;
|
|
|
|
(void)ino;
|
|
|
|
d = lo_dirp(req, fi);
|
|
if (!d) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
fd = dirfd(d->dp);
|
|
if (datasync) {
|
|
res = fdatasync(fd);
|
|
} else {
|
|
res = fsync(fd);
|
|
}
|
|
|
|
lo_dirp_put(&d);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
static void lo_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
|
|
{
|
|
int fd;
|
|
ssize_t fh;
|
|
char buf[64];
|
|
struct lo_data *lo = lo_data(req);
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_open(ino=%" PRIu64 ", flags=%d)\n", ino,
|
|
fi->flags);
|
|
|
|
update_open_flags(lo->writeback, fi);
|
|
|
|
sprintf(buf, "%i", lo_fd(req, ino));
|
|
fd = openat(lo->proc_self_fd, buf, fi->flags & ~O_NOFOLLOW);
|
|
if (fd == -1) {
|
|
return (void)fuse_reply_err(req, errno);
|
|
}
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
fh = lo_add_fd_mapping(req, fd);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
if (fh == -1) {
|
|
close(fd);
|
|
fuse_reply_err(req, ENOMEM);
|
|
return;
|
|
}
|
|
|
|
fi->fh = fh;
|
|
if (lo->cache == CACHE_NONE) {
|
|
fi->direct_io = 1;
|
|
} else if (lo->cache == CACHE_ALWAYS) {
|
|
fi->keep_cache = 1;
|
|
}
|
|
fuse_reply_open(req, fi);
|
|
}
|
|
|
|
static void lo_release(fuse_req_t req, fuse_ino_t ino,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_map_elem *elem;
|
|
int fd = -1;
|
|
|
|
(void)ino;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
elem = lo_map_get(&lo->fd_map, fi->fh);
|
|
if (elem) {
|
|
fd = elem->fd;
|
|
elem = NULL;
|
|
lo_map_remove(&lo->fd_map, fi->fh);
|
|
}
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
close(fd);
|
|
fuse_reply_err(req, 0);
|
|
}
|
|
|
|
static void lo_flush(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
|
|
{
|
|
int res;
|
|
(void)ino;
|
|
struct lo_inode *inode;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
/* An fd is going away. Cleanup associated posix locks */
|
|
pthread_mutex_lock(&inode->plock_mutex);
|
|
g_hash_table_remove(inode->posix_locks, GUINT_TO_POINTER(fi->lock_owner));
|
|
pthread_mutex_unlock(&inode->plock_mutex);
|
|
|
|
res = close(dup(lo_fi_fd(req, fi)));
|
|
lo_inode_put(lo_data(req), &inode);
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
int res;
|
|
int fd;
|
|
char *buf;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_fsync(ino=%" PRIu64 ", fi=0x%p)\n", ino,
|
|
(void *)fi);
|
|
|
|
if (!fi) {
|
|
struct lo_data *lo = lo_data(req);
|
|
|
|
res = asprintf(&buf, "%i", lo_fd(req, ino));
|
|
if (res == -1) {
|
|
return (void)fuse_reply_err(req, errno);
|
|
}
|
|
|
|
fd = openat(lo->proc_self_fd, buf, O_RDWR);
|
|
free(buf);
|
|
if (fd == -1) {
|
|
return (void)fuse_reply_err(req, errno);
|
|
}
|
|
} else {
|
|
fd = lo_fi_fd(req, fi);
|
|
}
|
|
|
|
if (datasync) {
|
|
res = fdatasync(fd);
|
|
} else {
|
|
res = fsync(fd);
|
|
}
|
|
if (!fi) {
|
|
close(fd);
|
|
}
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
static void lo_read(fuse_req_t req, fuse_ino_t ino, size_t size, off_t offset,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
struct fuse_bufvec buf = FUSE_BUFVEC_INIT(size);
|
|
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_read(ino=%" PRIu64 ", size=%zd, "
|
|
"off=%lu)\n",
|
|
ino, size, (unsigned long)offset);
|
|
|
|
buf.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
|
|
buf.buf[0].fd = lo_fi_fd(req, fi);
|
|
buf.buf[0].pos = offset;
|
|
|
|
fuse_reply_data(req, &buf);
|
|
}
|
|
|
|
static void lo_write_buf(fuse_req_t req, fuse_ino_t ino,
|
|
struct fuse_bufvec *in_buf, off_t off,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
(void)ino;
|
|
ssize_t res;
|
|
struct fuse_bufvec out_buf = FUSE_BUFVEC_INIT(fuse_buf_size(in_buf));
|
|
bool cap_fsetid_dropped = false;
|
|
|
|
out_buf.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
|
|
out_buf.buf[0].fd = lo_fi_fd(req, fi);
|
|
out_buf.buf[0].pos = off;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_write_buf(ino=%" PRIu64 ", size=%zd, off=%lu)\n", ino,
|
|
out_buf.buf[0].size, (unsigned long)off);
|
|
|
|
/*
|
|
* If kill_priv is set, drop CAP_FSETID which should lead to kernel
|
|
* clearing setuid/setgid on file.
|
|
*/
|
|
if (fi->kill_priv) {
|
|
res = drop_effective_cap("FSETID", &cap_fsetid_dropped);
|
|
if (res != 0) {
|
|
fuse_reply_err(req, res);
|
|
return;
|
|
}
|
|
}
|
|
|
|
res = fuse_buf_copy(&out_buf, in_buf);
|
|
if (res < 0) {
|
|
fuse_reply_err(req, -res);
|
|
} else {
|
|
fuse_reply_write(req, (size_t)res);
|
|
}
|
|
|
|
if (cap_fsetid_dropped) {
|
|
res = gain_effective_cap("FSETID");
|
|
if (res) {
|
|
fuse_log(FUSE_LOG_ERR, "Failed to gain CAP_FSETID\n");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void lo_statfs(fuse_req_t req, fuse_ino_t ino)
|
|
{
|
|
int res;
|
|
struct statvfs stbuf;
|
|
|
|
res = fstatvfs(lo_fd(req, ino), &stbuf);
|
|
if (res == -1) {
|
|
fuse_reply_err(req, errno);
|
|
} else {
|
|
fuse_reply_statfs(req, &stbuf);
|
|
}
|
|
}
|
|
|
|
static void lo_fallocate(fuse_req_t req, fuse_ino_t ino, int mode, off_t offset,
|
|
off_t length, struct fuse_file_info *fi)
|
|
{
|
|
int err = EOPNOTSUPP;
|
|
(void)ino;
|
|
|
|
#ifdef CONFIG_FALLOCATE
|
|
err = fallocate(lo_fi_fd(req, fi), mode, offset, length);
|
|
if (err < 0) {
|
|
err = errno;
|
|
}
|
|
|
|
#elif defined(CONFIG_POSIX_FALLOCATE)
|
|
if (mode) {
|
|
fuse_reply_err(req, EOPNOTSUPP);
|
|
return;
|
|
}
|
|
|
|
err = posix_fallocate(lo_fi_fd(req, fi), offset, length);
|
|
#endif
|
|
|
|
fuse_reply_err(req, err);
|
|
}
|
|
|
|
static void lo_flock(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi,
|
|
int op)
|
|
{
|
|
int res;
|
|
(void)ino;
|
|
|
|
res = flock(lo_fi_fd(req, fi), op);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
|
|
size_t size)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
char *value = NULL;
|
|
char procname[64];
|
|
struct lo_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
int fd = -1;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_getxattr(ino=%" PRIu64 ", name=%s size=%zd)\n",
|
|
ino, name, size);
|
|
|
|
if (size) {
|
|
value = malloc(size);
|
|
if (!value) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
sprintf(procname, "%i", inode->fd);
|
|
/*
|
|
* It is not safe to open() non-regular/non-dir files in file server
|
|
* unless O_PATH is used, so use that method for regular files/dir
|
|
* only (as it seems giving less performance overhead).
|
|
* Otherwise, call fchdir() to avoid open().
|
|
*/
|
|
if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) {
|
|
fd = openat(lo->proc_self_fd, procname, O_RDONLY);
|
|
if (fd < 0) {
|
|
goto out_err;
|
|
}
|
|
ret = fgetxattr(fd, name, value, size);
|
|
} else {
|
|
/* fchdir should not fail here */
|
|
assert(fchdir(lo->proc_self_fd) == 0);
|
|
ret = getxattr(procname, name, value, size);
|
|
assert(fchdir(lo->root.fd) == 0);
|
|
}
|
|
|
|
if (ret == -1) {
|
|
goto out_err;
|
|
}
|
|
if (size) {
|
|
saverr = 0;
|
|
if (ret == 0) {
|
|
goto out;
|
|
}
|
|
fuse_reply_buf(req, value, ret);
|
|
} else {
|
|
fuse_reply_xattr(req, ret);
|
|
}
|
|
out_free:
|
|
free(value);
|
|
|
|
if (fd >= 0) {
|
|
close(fd);
|
|
}
|
|
|
|
lo_inode_put(lo, &inode);
|
|
return;
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
out:
|
|
fuse_reply_err(req, saverr);
|
|
goto out_free;
|
|
}
|
|
|
|
static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size)
|
|
{
|
|
struct lo_data *lo = lo_data(req);
|
|
char *value = NULL;
|
|
char procname[64];
|
|
struct lo_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
int fd = -1;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_listxattr(ino=%" PRIu64 ", size=%zd)\n", ino,
|
|
size);
|
|
|
|
if (size) {
|
|
value = malloc(size);
|
|
if (!value) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
sprintf(procname, "%i", inode->fd);
|
|
if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) {
|
|
fd = openat(lo->proc_self_fd, procname, O_RDONLY);
|
|
if (fd < 0) {
|
|
goto out_err;
|
|
}
|
|
ret = flistxattr(fd, value, size);
|
|
} else {
|
|
/* fchdir should not fail here */
|
|
assert(fchdir(lo->proc_self_fd) == 0);
|
|
ret = listxattr(procname, value, size);
|
|
assert(fchdir(lo->root.fd) == 0);
|
|
}
|
|
|
|
if (ret == -1) {
|
|
goto out_err;
|
|
}
|
|
if (size) {
|
|
saverr = 0;
|
|
if (ret == 0) {
|
|
goto out;
|
|
}
|
|
fuse_reply_buf(req, value, ret);
|
|
} else {
|
|
fuse_reply_xattr(req, ret);
|
|
}
|
|
out_free:
|
|
free(value);
|
|
|
|
if (fd >= 0) {
|
|
close(fd);
|
|
}
|
|
|
|
lo_inode_put(lo, &inode);
|
|
return;
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
out:
|
|
fuse_reply_err(req, saverr);
|
|
goto out_free;
|
|
}
|
|
|
|
static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *name,
|
|
const char *value, size_t size, int flags)
|
|
{
|
|
char procname[64];
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
int fd = -1;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_setxattr(ino=%" PRIu64
|
|
", name=%s value=%s size=%zd)\n", ino, name, value, size);
|
|
|
|
sprintf(procname, "%i", inode->fd);
|
|
if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) {
|
|
fd = openat(lo->proc_self_fd, procname, O_RDONLY);
|
|
if (fd < 0) {
|
|
saverr = errno;
|
|
goto out;
|
|
}
|
|
ret = fsetxattr(fd, name, value, size, flags);
|
|
} else {
|
|
/* fchdir should not fail here */
|
|
assert(fchdir(lo->proc_self_fd) == 0);
|
|
ret = setxattr(procname, name, value, size, flags);
|
|
assert(fchdir(lo->root.fd) == 0);
|
|
}
|
|
|
|
saverr = ret == -1 ? errno : 0;
|
|
|
|
out:
|
|
if (fd >= 0) {
|
|
close(fd);
|
|
}
|
|
|
|
lo_inode_put(lo, &inode);
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *name)
|
|
{
|
|
char procname[64];
|
|
struct lo_data *lo = lo_data(req);
|
|
struct lo_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
int fd = -1;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_removexattr(ino=%" PRIu64 ", name=%s)\n", ino,
|
|
name);
|
|
|
|
sprintf(procname, "%i", inode->fd);
|
|
if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) {
|
|
fd = openat(lo->proc_self_fd, procname, O_RDONLY);
|
|
if (fd < 0) {
|
|
saverr = errno;
|
|
goto out;
|
|
}
|
|
ret = fremovexattr(fd, name);
|
|
} else {
|
|
/* fchdir should not fail here */
|
|
assert(fchdir(lo->proc_self_fd) == 0);
|
|
ret = removexattr(procname, name);
|
|
assert(fchdir(lo->root.fd) == 0);
|
|
}
|
|
|
|
saverr = ret == -1 ? errno : 0;
|
|
|
|
out:
|
|
if (fd >= 0) {
|
|
close(fd);
|
|
}
|
|
|
|
lo_inode_put(lo, &inode);
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
#ifdef HAVE_COPY_FILE_RANGE
|
|
static void lo_copy_file_range(fuse_req_t req, fuse_ino_t ino_in, off_t off_in,
|
|
struct fuse_file_info *fi_in, fuse_ino_t ino_out,
|
|
off_t off_out, struct fuse_file_info *fi_out,
|
|
size_t len, int flags)
|
|
{
|
|
int in_fd, out_fd;
|
|
ssize_t res;
|
|
|
|
in_fd = lo_fi_fd(req, fi_in);
|
|
out_fd = lo_fi_fd(req, fi_out);
|
|
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_copy_file_range(ino=%" PRIu64 "/fd=%d, "
|
|
"off=%lu, ino=%" PRIu64 "/fd=%d, "
|
|
"off=%lu, size=%zd, flags=0x%x)\n",
|
|
ino_in, in_fd, off_in, ino_out, out_fd, off_out, len, flags);
|
|
|
|
res = copy_file_range(in_fd, &off_in, out_fd, &off_out, len, flags);
|
|
if (res < 0) {
|
|
fuse_reply_err(req, errno);
|
|
} else {
|
|
fuse_reply_write(req, res);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence,
|
|
struct fuse_file_info *fi)
|
|
{
|
|
off_t res;
|
|
|
|
(void)ino;
|
|
res = lseek(lo_fi_fd(req, fi), off, whence);
|
|
if (res != -1) {
|
|
fuse_reply_lseek(req, res);
|
|
} else {
|
|
fuse_reply_err(req, errno);
|
|
}
|
|
}
|
|
|
|
static void lo_destroy(void *userdata)
|
|
{
|
|
struct lo_data *lo = (struct lo_data *)userdata;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
while (true) {
|
|
GHashTableIter iter;
|
|
gpointer key, value;
|
|
|
|
g_hash_table_iter_init(&iter, lo->inodes);
|
|
if (!g_hash_table_iter_next(&iter, &key, &value)) {
|
|
break;
|
|
}
|
|
|
|
struct lo_inode *inode = value;
|
|
unref_inode(lo, inode, inode->nlookup);
|
|
}
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
}
|
|
|
|
static struct fuse_lowlevel_ops lo_oper = {
|
|
.init = lo_init,
|
|
.lookup = lo_lookup,
|
|
.mkdir = lo_mkdir,
|
|
.mknod = lo_mknod,
|
|
.symlink = lo_symlink,
|
|
.link = lo_link,
|
|
.unlink = lo_unlink,
|
|
.rmdir = lo_rmdir,
|
|
.rename = lo_rename,
|
|
.forget = lo_forget,
|
|
.forget_multi = lo_forget_multi,
|
|
.getattr = lo_getattr,
|
|
.setattr = lo_setattr,
|
|
.readlink = lo_readlink,
|
|
.opendir = lo_opendir,
|
|
.readdir = lo_readdir,
|
|
.readdirplus = lo_readdirplus,
|
|
.releasedir = lo_releasedir,
|
|
.fsyncdir = lo_fsyncdir,
|
|
.create = lo_create,
|
|
.getlk = lo_getlk,
|
|
.setlk = lo_setlk,
|
|
.open = lo_open,
|
|
.release = lo_release,
|
|
.flush = lo_flush,
|
|
.fsync = lo_fsync,
|
|
.read = lo_read,
|
|
.write_buf = lo_write_buf,
|
|
.statfs = lo_statfs,
|
|
.fallocate = lo_fallocate,
|
|
.flock = lo_flock,
|
|
.getxattr = lo_getxattr,
|
|
.listxattr = lo_listxattr,
|
|
.setxattr = lo_setxattr,
|
|
.removexattr = lo_removexattr,
|
|
#ifdef HAVE_COPY_FILE_RANGE
|
|
.copy_file_range = lo_copy_file_range,
|
|
#endif
|
|
.lseek = lo_lseek,
|
|
.destroy = lo_destroy,
|
|
};
|
|
|
|
/* Print vhost-user.json backend program capabilities */
|
|
static void print_capabilities(void)
|
|
{
|
|
printf("{\n");
|
|
printf(" \"type\": \"fs\"\n");
|
|
printf("}\n");
|
|
}
|
|
|
|
/*
|
|
* Drop all Linux capabilities because the wait parent process only needs to
|
|
* sit in waitpid(2) and terminate.
|
|
*/
|
|
static void setup_wait_parent_capabilities(void)
|
|
{
|
|
capng_setpid(syscall(SYS_gettid));
|
|
capng_clear(CAPNG_SELECT_BOTH);
|
|
capng_apply(CAPNG_SELECT_BOTH);
|
|
}
|
|
|
|
/*
|
|
* Move to a new mount, net, and pid namespaces to isolate this process.
|
|
*/
|
|
static void setup_namespaces(struct lo_data *lo, struct fuse_session *se)
|
|
{
|
|
pid_t child;
|
|
char template[] = "virtiofsd-XXXXXX";
|
|
char *tmpdir;
|
|
|
|
/*
|
|
* Create a new pid namespace for *child* processes. We'll have to
|
|
* fork in order to enter the new pid namespace. A new mount namespace
|
|
* is also needed so that we can remount /proc for the new pid
|
|
* namespace.
|
|
*
|
|
* Our UNIX domain sockets have been created. Now we can move to
|
|
* an empty network namespace to prevent TCP/IP and other network
|
|
* activity in case this process is compromised.
|
|
*/
|
|
if (unshare(CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWNET) != 0) {
|
|
fuse_log(FUSE_LOG_ERR, "unshare(CLONE_NEWPID | CLONE_NEWNS): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
child = fork();
|
|
if (child < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "fork() failed: %m\n");
|
|
exit(1);
|
|
}
|
|
if (child > 0) {
|
|
pid_t waited;
|
|
int wstatus;
|
|
|
|
setup_wait_parent_capabilities();
|
|
|
|
/* The parent waits for the child */
|
|
do {
|
|
waited = waitpid(child, &wstatus, 0);
|
|
} while (waited < 0 && errno == EINTR && !se->exited);
|
|
|
|
/* We were terminated by a signal, see fuse_signals.c */
|
|
if (se->exited) {
|
|
exit(0);
|
|
}
|
|
|
|
if (WIFEXITED(wstatus)) {
|
|
exit(WEXITSTATUS(wstatus));
|
|
}
|
|
|
|
exit(1);
|
|
}
|
|
|
|
/* Send us SIGTERM when the parent thread terminates, see prctl(2) */
|
|
prctl(PR_SET_PDEATHSIG, SIGTERM);
|
|
|
|
/*
|
|
* If the mounts have shared propagation then we want to opt out so our
|
|
* mount changes don't affect the parent mount namespace.
|
|
*/
|
|
if (mount(NULL, "/", NULL, MS_REC | MS_SLAVE, NULL) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "mount(/, MS_REC|MS_SLAVE): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
/* The child must remount /proc to use the new pid namespace */
|
|
if (mount("proc", "/proc", "proc",
|
|
MS_NODEV | MS_NOEXEC | MS_NOSUID | MS_RELATIME, NULL) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "mount(/proc): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
tmpdir = mkdtemp(template);
|
|
if (!tmpdir) {
|
|
fuse_log(FUSE_LOG_ERR, "tmpdir(%s): %m\n", template);
|
|
exit(1);
|
|
}
|
|
|
|
if (mount("/proc/self/fd", tmpdir, NULL, MS_BIND, NULL) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "mount(/proc/self/fd, %s, MS_BIND): %m\n",
|
|
tmpdir);
|
|
exit(1);
|
|
}
|
|
|
|
/* Now we can get our /proc/self/fd directory file descriptor */
|
|
lo->proc_self_fd = open(tmpdir, O_PATH);
|
|
if (lo->proc_self_fd == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "open(%s, O_PATH): %m\n", tmpdir);
|
|
exit(1);
|
|
}
|
|
|
|
if (umount2(tmpdir, MNT_DETACH) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "umount2(%s, MNT_DETACH): %m\n", tmpdir);
|
|
exit(1);
|
|
}
|
|
|
|
if (rmdir(tmpdir) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "rmdir(%s): %m\n", tmpdir);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Capture the capability state, we'll need to restore this for individual
|
|
* threads later; see load_capng.
|
|
*/
|
|
static void setup_capng(void)
|
|
{
|
|
/* Note this accesses /proc so has to happen before the sandbox */
|
|
if (capng_get_caps_process()) {
|
|
fuse_log(FUSE_LOG_ERR, "capng_get_caps_process\n");
|
|
exit(1);
|
|
}
|
|
pthread_mutex_init(&cap.mutex, NULL);
|
|
pthread_mutex_lock(&cap.mutex);
|
|
cap.saved = capng_save_state();
|
|
if (!cap.saved) {
|
|
fuse_log(FUSE_LOG_ERR, "capng_save_state\n");
|
|
exit(1);
|
|
}
|
|
pthread_mutex_unlock(&cap.mutex);
|
|
}
|
|
|
|
static void cleanup_capng(void)
|
|
{
|
|
free(cap.saved);
|
|
cap.saved = NULL;
|
|
pthread_mutex_destroy(&cap.mutex);
|
|
}
|
|
|
|
|
|
/*
|
|
* Make the source directory our root so symlinks cannot escape and no other
|
|
* files are accessible. Assumes unshare(CLONE_NEWNS) was already called.
|
|
*/
|
|
static void setup_mounts(const char *source)
|
|
{
|
|
int oldroot;
|
|
int newroot;
|
|
|
|
if (mount(source, source, NULL, MS_BIND | MS_REC, NULL) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "mount(%s, %s, MS_BIND): %m\n", source, source);
|
|
exit(1);
|
|
}
|
|
|
|
/* This magic is based on lxc's lxc_pivot_root() */
|
|
oldroot = open("/", O_DIRECTORY | O_RDONLY | O_CLOEXEC);
|
|
if (oldroot < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "open(/): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
newroot = open(source, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
|
|
if (newroot < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "open(%s): %m\n", source);
|
|
exit(1);
|
|
}
|
|
|
|
if (fchdir(newroot) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "fchdir(newroot): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (syscall(__NR_pivot_root, ".", ".") < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "pivot_root(., .): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (fchdir(oldroot) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "fchdir(oldroot): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (mount("", ".", "", MS_SLAVE | MS_REC, NULL) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "mount(., MS_SLAVE | MS_REC): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (umount2(".", MNT_DETACH) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "umount2(., MNT_DETACH): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (fchdir(newroot) < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "fchdir(newroot): %m\n");
|
|
exit(1);
|
|
}
|
|
|
|
close(newroot);
|
|
close(oldroot);
|
|
}
|
|
|
|
/*
|
|
* Only keep whitelisted capabilities that are needed for file system operation
|
|
* The (possibly NULL) modcaps_in string passed in is free'd before exit.
|
|
*/
|
|
static void setup_capabilities(char *modcaps_in)
|
|
{
|
|
char *modcaps = modcaps_in;
|
|
pthread_mutex_lock(&cap.mutex);
|
|
capng_restore_state(&cap.saved);
|
|
|
|
/*
|
|
* Whitelist file system-related capabilities that are needed for a file
|
|
* server to act like root. Drop everything else like networking and
|
|
* sysadmin capabilities.
|
|
*
|
|
* Exclusions:
|
|
* 1. CAP_LINUX_IMMUTABLE is not included because it's only used via ioctl
|
|
* and we don't support that.
|
|
* 2. CAP_MAC_OVERRIDE is not included because it only seems to be
|
|
* used by the Smack LSM. Omit it until there is demand for it.
|
|
*/
|
|
capng_setpid(syscall(SYS_gettid));
|
|
capng_clear(CAPNG_SELECT_BOTH);
|
|
if (capng_updatev(CAPNG_ADD, CAPNG_PERMITTED | CAPNG_EFFECTIVE,
|
|
CAP_CHOWN,
|
|
CAP_DAC_OVERRIDE,
|
|
CAP_DAC_READ_SEARCH,
|
|
CAP_FOWNER,
|
|
CAP_FSETID,
|
|
CAP_SETGID,
|
|
CAP_SETUID,
|
|
CAP_MKNOD,
|
|
CAP_SETFCAP,
|
|
-1)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: capng_updatev failed\n", __func__);
|
|
exit(1);
|
|
}
|
|
|
|
/*
|
|
* The modcaps option is a colon separated list of caps,
|
|
* each preceded by either + or -.
|
|
*/
|
|
while (modcaps) {
|
|
capng_act_t action;
|
|
int cap;
|
|
|
|
char *next = strchr(modcaps, ':');
|
|
if (next) {
|
|
*next = '\0';
|
|
next++;
|
|
}
|
|
|
|
switch (modcaps[0]) {
|
|
case '+':
|
|
action = CAPNG_ADD;
|
|
break;
|
|
|
|
case '-':
|
|
action = CAPNG_DROP;
|
|
break;
|
|
|
|
default:
|
|
fuse_log(FUSE_LOG_ERR,
|
|
"%s: Expecting '+'/'-' in modcaps but found '%c'\n",
|
|
__func__, modcaps[0]);
|
|
exit(1);
|
|
}
|
|
cap = capng_name_to_capability(modcaps + 1);
|
|
if (cap < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: Unknown capability '%s'\n", __func__,
|
|
modcaps);
|
|
exit(1);
|
|
}
|
|
if (capng_update(action, CAPNG_PERMITTED | CAPNG_EFFECTIVE, cap)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: capng_update failed for '%s'\n",
|
|
__func__, modcaps);
|
|
exit(1);
|
|
}
|
|
|
|
modcaps = next;
|
|
}
|
|
g_free(modcaps_in);
|
|
|
|
if (capng_apply(CAPNG_SELECT_BOTH)) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: capng_apply failed\n", __func__);
|
|
exit(1);
|
|
}
|
|
|
|
cap.saved = capng_save_state();
|
|
if (!cap.saved) {
|
|
fuse_log(FUSE_LOG_ERR, "%s: capng_save_state failed\n", __func__);
|
|
exit(1);
|
|
}
|
|
pthread_mutex_unlock(&cap.mutex);
|
|
}
|
|
|
|
/*
|
|
* Lock down this process to prevent access to other processes or files outside
|
|
* source directory. This reduces the impact of arbitrary code execution bugs.
|
|
*/
|
|
static void setup_sandbox(struct lo_data *lo, struct fuse_session *se,
|
|
bool enable_syslog)
|
|
{
|
|
setup_namespaces(lo, se);
|
|
setup_mounts(lo->source);
|
|
setup_seccomp(enable_syslog);
|
|
setup_capabilities(g_strdup(lo->modcaps));
|
|
}
|
|
|
|
/* Set the maximum number of open file descriptors */
|
|
static void setup_nofile_rlimit(unsigned long rlimit_nofile)
|
|
{
|
|
struct rlimit rlim = {
|
|
.rlim_cur = rlimit_nofile,
|
|
.rlim_max = rlimit_nofile,
|
|
};
|
|
|
|
if (rlimit_nofile == 0) {
|
|
return; /* nothing to do */
|
|
}
|
|
|
|
if (setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
|
|
/* Ignore SELinux denials */
|
|
if (errno == EPERM) {
|
|
return;
|
|
}
|
|
|
|
fuse_log(FUSE_LOG_ERR, "setrlimit(RLIMIT_NOFILE): %m\n");
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
static void log_func(enum fuse_log_level level, const char *fmt, va_list ap)
|
|
{
|
|
g_autofree char *localfmt = NULL;
|
|
|
|
if (current_log_level < level) {
|
|
return;
|
|
}
|
|
|
|
if (current_log_level == FUSE_LOG_DEBUG) {
|
|
if (!use_syslog) {
|
|
localfmt = g_strdup_printf("[%" PRId64 "] [ID: %08ld] %s",
|
|
get_clock(), syscall(__NR_gettid), fmt);
|
|
} else {
|
|
localfmt = g_strdup_printf("[ID: %08ld] %s", syscall(__NR_gettid),
|
|
fmt);
|
|
}
|
|
fmt = localfmt;
|
|
}
|
|
|
|
if (use_syslog) {
|
|
int priority = LOG_ERR;
|
|
switch (level) {
|
|
case FUSE_LOG_EMERG:
|
|
priority = LOG_EMERG;
|
|
break;
|
|
case FUSE_LOG_ALERT:
|
|
priority = LOG_ALERT;
|
|
break;
|
|
case FUSE_LOG_CRIT:
|
|
priority = LOG_CRIT;
|
|
break;
|
|
case FUSE_LOG_ERR:
|
|
priority = LOG_ERR;
|
|
break;
|
|
case FUSE_LOG_WARNING:
|
|
priority = LOG_WARNING;
|
|
break;
|
|
case FUSE_LOG_NOTICE:
|
|
priority = LOG_NOTICE;
|
|
break;
|
|
case FUSE_LOG_INFO:
|
|
priority = LOG_INFO;
|
|
break;
|
|
case FUSE_LOG_DEBUG:
|
|
priority = LOG_DEBUG;
|
|
break;
|
|
}
|
|
vsyslog(priority, fmt, ap);
|
|
} else {
|
|
vfprintf(stderr, fmt, ap);
|
|
}
|
|
}
|
|
|
|
static void setup_root(struct lo_data *lo, struct lo_inode *root)
|
|
{
|
|
int fd, res;
|
|
struct stat stat;
|
|
|
|
fd = open("/", O_PATH);
|
|
if (fd == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "open(%s, O_PATH): %m\n", lo->source);
|
|
exit(1);
|
|
}
|
|
|
|
res = fstatat(fd, "", &stat, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "fstatat(%s): %m\n", lo->source);
|
|
exit(1);
|
|
}
|
|
|
|
root->filetype = S_IFDIR;
|
|
root->fd = fd;
|
|
root->key.ino = stat.st_ino;
|
|
root->key.dev = stat.st_dev;
|
|
root->nlookup = 2;
|
|
g_atomic_int_set(&root->refcount, 2);
|
|
}
|
|
|
|
static guint lo_key_hash(gconstpointer key)
|
|
{
|
|
const struct lo_key *lkey = key;
|
|
|
|
return (guint)lkey->ino + (guint)lkey->dev;
|
|
}
|
|
|
|
static gboolean lo_key_equal(gconstpointer a, gconstpointer b)
|
|
{
|
|
const struct lo_key *la = a;
|
|
const struct lo_key *lb = b;
|
|
|
|
return la->ino == lb->ino && la->dev == lb->dev;
|
|
}
|
|
|
|
static void fuse_lo_data_cleanup(struct lo_data *lo)
|
|
{
|
|
if (lo->inodes) {
|
|
g_hash_table_destroy(lo->inodes);
|
|
}
|
|
lo_map_destroy(&lo->fd_map);
|
|
lo_map_destroy(&lo->dirp_map);
|
|
lo_map_destroy(&lo->ino_map);
|
|
|
|
if (lo->proc_self_fd >= 0) {
|
|
close(lo->proc_self_fd);
|
|
}
|
|
|
|
if (lo->root.fd >= 0) {
|
|
close(lo->root.fd);
|
|
}
|
|
|
|
free(lo->source);
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
|
|
struct fuse_session *se;
|
|
struct fuse_cmdline_opts opts;
|
|
struct lo_data lo = {
|
|
.debug = 0,
|
|
.writeback = 0,
|
|
.posix_lock = 1,
|
|
.proc_self_fd = -1,
|
|
};
|
|
struct lo_map_elem *root_elem;
|
|
int ret = -1;
|
|
|
|
/* Don't mask creation mode, kernel already did that */
|
|
umask(0);
|
|
|
|
pthread_mutex_init(&lo.mutex, NULL);
|
|
lo.inodes = g_hash_table_new(lo_key_hash, lo_key_equal);
|
|
lo.root.fd = -1;
|
|
lo.root.fuse_ino = FUSE_ROOT_ID;
|
|
lo.cache = CACHE_AUTO;
|
|
|
|
/*
|
|
* Set up the ino map like this:
|
|
* [0] Reserved (will not be used)
|
|
* [1] Root inode
|
|
*/
|
|
lo_map_init(&lo.ino_map);
|
|
lo_map_reserve(&lo.ino_map, 0)->in_use = false;
|
|
root_elem = lo_map_reserve(&lo.ino_map, lo.root.fuse_ino);
|
|
root_elem->inode = &lo.root;
|
|
|
|
lo_map_init(&lo.dirp_map);
|
|
lo_map_init(&lo.fd_map);
|
|
|
|
if (fuse_parse_cmdline(&args, &opts) != 0) {
|
|
goto err_out1;
|
|
}
|
|
fuse_set_log_func(log_func);
|
|
use_syslog = opts.syslog;
|
|
if (use_syslog) {
|
|
openlog("virtiofsd", LOG_PID, LOG_DAEMON);
|
|
}
|
|
|
|
if (opts.show_help) {
|
|
printf("usage: %s [options]\n\n", argv[0]);
|
|
fuse_cmdline_help();
|
|
printf(" -o source=PATH shared directory tree\n");
|
|
fuse_lowlevel_help();
|
|
ret = 0;
|
|
goto err_out1;
|
|
} else if (opts.show_version) {
|
|
fuse_lowlevel_version();
|
|
ret = 0;
|
|
goto err_out1;
|
|
} else if (opts.print_capabilities) {
|
|
print_capabilities();
|
|
ret = 0;
|
|
goto err_out1;
|
|
}
|
|
|
|
if (fuse_opt_parse(&args, &lo, lo_opts, NULL) == -1) {
|
|
goto err_out1;
|
|
}
|
|
|
|
/*
|
|
* log_level is 0 if not configured via cmd options (0 is LOG_EMERG,
|
|
* and we don't use this log level).
|
|
*/
|
|
if (opts.log_level != 0) {
|
|
current_log_level = opts.log_level;
|
|
}
|
|
lo.debug = opts.debug;
|
|
if (lo.debug) {
|
|
current_log_level = FUSE_LOG_DEBUG;
|
|
}
|
|
if (lo.source) {
|
|
struct stat stat;
|
|
int res;
|
|
|
|
res = lstat(lo.source, &stat);
|
|
if (res == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "failed to stat source (\"%s\"): %m\n",
|
|
lo.source);
|
|
exit(1);
|
|
}
|
|
if (!S_ISDIR(stat.st_mode)) {
|
|
fuse_log(FUSE_LOG_ERR, "source is not a directory\n");
|
|
exit(1);
|
|
}
|
|
} else {
|
|
lo.source = strdup("/");
|
|
}
|
|
if (!lo.timeout_set) {
|
|
switch (lo.cache) {
|
|
case CACHE_NONE:
|
|
lo.timeout = 0.0;
|
|
break;
|
|
|
|
case CACHE_AUTO:
|
|
lo.timeout = 1.0;
|
|
break;
|
|
|
|
case CACHE_ALWAYS:
|
|
lo.timeout = 86400.0;
|
|
break;
|
|
}
|
|
} else if (lo.timeout < 0) {
|
|
fuse_log(FUSE_LOG_ERR, "timeout is negative (%lf)\n", lo.timeout);
|
|
exit(1);
|
|
}
|
|
|
|
se = fuse_session_new(&args, &lo_oper, sizeof(lo_oper), &lo);
|
|
if (se == NULL) {
|
|
goto err_out1;
|
|
}
|
|
|
|
if (fuse_set_signal_handlers(se) != 0) {
|
|
goto err_out2;
|
|
}
|
|
|
|
if (fuse_session_mount(se) != 0) {
|
|
goto err_out3;
|
|
}
|
|
|
|
fuse_daemonize(opts.foreground);
|
|
|
|
setup_nofile_rlimit(opts.rlimit_nofile);
|
|
|
|
/* Must be before sandbox since it wants /proc */
|
|
setup_capng();
|
|
|
|
setup_sandbox(&lo, se, opts.syslog);
|
|
|
|
setup_root(&lo, &lo.root);
|
|
/* Block until ctrl+c or fusermount -u */
|
|
ret = virtio_loop(se);
|
|
|
|
fuse_session_unmount(se);
|
|
cleanup_capng();
|
|
err_out3:
|
|
fuse_remove_signal_handlers(se);
|
|
err_out2:
|
|
fuse_session_destroy(se);
|
|
err_out1:
|
|
fuse_opt_free_args(&args);
|
|
|
|
fuse_lo_data_cleanup(&lo);
|
|
|
|
return ret ? 1 : 0;
|
|
}
|