25dae28c58
Several FUSE requests contain single path components. A correct FUSE client sends well-formed path components but there is currently no input validation in case something went wrong or the client is malicious. Refuse ".", "..", and paths containing '/' when we expect a path component. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2014 lines
47 KiB
C
2014 lines
47 KiB
C
/*
|
|
* FUSE: Filesystem in Userspace
|
|
* Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
|
|
*
|
|
* This program can be distributed under the terms of the GNU GPLv2.
|
|
* See the file COPYING.
|
|
*/
|
|
|
|
/*
|
|
*
|
|
* This file system mirrors the existing file system hierarchy of the
|
|
* system, starting at the root file system. This is implemented by
|
|
* just "passing through" all requests to the corresponding user-space
|
|
* libc functions. In contrast to passthrough.c and passthrough_fh.c,
|
|
* this implementation uses the low-level API. Its performance should
|
|
* be the least bad among the three, but many operations are not
|
|
* implemented. In particular, it is not possible to remove files (or
|
|
* directories) because the code necessary to defer actual removal
|
|
* until the file is not opened anymore would make the example much
|
|
* more complicated.
|
|
*
|
|
* When writeback caching is enabled (-o writeback mount option), it
|
|
* is only possible to write to files for which the mounting user has
|
|
* read permissions. This is because the writeback cache requires the
|
|
* kernel to be able to issue read requests for all files (which the
|
|
* passthrough filesystem cannot satisfy if it can't read the file in
|
|
* the underlying filesystem).
|
|
*
|
|
* Compile with:
|
|
*
|
|
* gcc -Wall passthrough_ll.c `pkg-config fuse3 --cflags --libs` -o
|
|
* passthrough_ll
|
|
*
|
|
* ## Source code ##
|
|
* \include passthrough_ll.c
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "fuse_virtio.h"
|
|
#include "fuse_lowlevel.h"
|
|
#include <assert.h>
|
|
#include <dirent.h>
|
|
#include <errno.h>
|
|
#include <inttypes.h>
|
|
#include <limits.h>
|
|
#include <pthread.h>
|
|
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/file.h>
|
|
#include <sys/syscall.h>
|
|
#include <sys/xattr.h>
|
|
#include <unistd.h>
|
|
|
|
#include "passthrough_helpers.h"
|
|
|
|
struct lo_map_elem {
|
|
union {
|
|
struct lo_inode *inode;
|
|
struct lo_dirp *dirp;
|
|
int fd;
|
|
ssize_t freelist;
|
|
};
|
|
bool in_use;
|
|
};
|
|
|
|
/* Maps FUSE fh or ino values to internal objects */
|
|
struct lo_map {
|
|
struct lo_map_elem *elems;
|
|
size_t nelems;
|
|
ssize_t freelist;
|
|
};
|
|
|
|
struct lo_inode {
|
|
struct lo_inode *next; /* protected by lo->mutex */
|
|
struct lo_inode *prev; /* protected by lo->mutex */
|
|
int fd;
|
|
bool is_symlink;
|
|
ino_t ino;
|
|
dev_t dev;
|
|
uint64_t refcount; /* protected by lo->mutex */
|
|
fuse_ino_t fuse_ino;
|
|
};
|
|
|
|
struct lo_cred {
|
|
uid_t euid;
|
|
gid_t egid;
|
|
};
|
|
|
|
enum {
|
|
CACHE_NEVER,
|
|
CACHE_NORMAL,
|
|
CACHE_ALWAYS,
|
|
};
|
|
|
|
struct lo_data {
|
|
pthread_mutex_t mutex;
|
|
int debug;
|
|
int norace;
|
|
int writeback;
|
|
int flock;
|
|
int xattr;
|
|
const char *source;
|
|
double timeout;
|
|
int cache;
|
|
int timeout_set;
|
|
struct lo_inode root; /* protected by lo->mutex */
|
|
struct lo_map ino_map; /* protected by lo->mutex */
|
|
struct lo_map dirp_map; /* protected by lo->mutex */
|
|
struct lo_map fd_map; /* protected by lo->mutex */
|
|
};
|
|
|
|
static const struct fuse_opt lo_opts[] = {
|
|
{ "writeback", offsetof(struct lo_data, writeback), 1 },
|
|
{ "no_writeback", offsetof(struct lo_data, writeback), 0 },
|
|
{ "source=%s", offsetof(struct lo_data, source), 0 },
|
|
{ "flock", offsetof(struct lo_data, flock), 1 },
|
|
{ "no_flock", offsetof(struct lo_data, flock), 0 },
|
|
{ "xattr", offsetof(struct lo_data, xattr), 1 },
|
|
{ "no_xattr", offsetof(struct lo_data, xattr), 0 },
|
|
{ "timeout=%lf", offsetof(struct lo_data, timeout), 0 },
|
|
{ "timeout=", offsetof(struct lo_data, timeout_set), 1 },
|
|
{ "cache=never", offsetof(struct lo_data, cache), CACHE_NEVER },
|
|
{ "cache=auto", offsetof(struct lo_data, cache), CACHE_NORMAL },
|
|
{ "cache=always", offsetof(struct lo_data, cache), CACHE_ALWAYS },
|
|
{ "norace", offsetof(struct lo_data, norace), 1 },
|
|
FUSE_OPT_END
|
|
};
|
|
|
|
static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n);
|
|
|
|
static struct lo_inode *lo_find(struct lo_data *lo, struct stat *st);
|
|
|
|
static int is_dot_or_dotdot(const char *name)
|
|
{
|
|
return name[0] == '.' &&
|
|
(name[1] == '\0' || (name[1] == '.' && name[2] == '\0'));
|
|
}
|
|
|
|
/* Is `path` a single path component that is not "." or ".."? */
|
|
static int is_safe_path_component(const char *path)
|
|
{
|
|
if (strchr(path, '/')) {
|
|
return 0;
|
|
}
|
|
|
|
return !is_dot_or_dotdot(path);
|
|
}
|
|
|
|
static struct lo_data *lo_data(fuse_req_t req)
|
|
{
|
|
return (struct lo_data *)fuse_req_userdata(req);
|
|
}
|
|
|
|
static void lo_map_init(struct lo_map *map)
|
|
{
|
|
map->elems = NULL;
|
|
map->nelems = 0;
|
|
map->freelist = -1;
|
|
}
|
|
|
|
static void lo_map_destroy(struct lo_map *map)
|
|
{
|
|
free(map->elems);
|
|
}
|
|
|
|
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) {
|
|
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;
|
|
}
|
|
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 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);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
if (!elem) {
|
|
return NULL;
|
|
}
|
|
|
|
return elem->inode;
|
|
}
|
|
|
|
static int lo_fd(fuse_req_t req, fuse_ino_t ino)
|
|
{
|
|
struct lo_inode *inode = lo_inode(req, ino);
|
|
return inode ? inode->fd : -1;
|
|
}
|
|
|
|
static bool lo_debug(fuse_req_t req)
|
|
{
|
|
return lo_data(req)->debug != 0;
|
|
}
|
|
|
|
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) {
|
|
if (lo->debug) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: activating writeback\n");
|
|
}
|
|
conn->want |= FUSE_CAP_WRITEBACK_CACHE;
|
|
}
|
|
if (lo->flock && conn->capable & FUSE_CAP_FLOCK_LOCKS) {
|
|
if (lo->debug) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_init: activating flock locks\n");
|
|
}
|
|
conn->want |= FUSE_CAP_FLOCK_LOCKS;
|
|
}
|
|
}
|
|
|
|
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_parent_and_name(struct lo_data *lo, struct lo_inode *inode,
|
|
char path[PATH_MAX], struct lo_inode **parent)
|
|
{
|
|
char procname[64];
|
|
char *last;
|
|
struct stat stat;
|
|
struct lo_inode *p;
|
|
int retries = 2;
|
|
int res;
|
|
|
|
retry:
|
|
sprintf(procname, "/proc/self/fd/%i", inode->fd);
|
|
|
|
res = readlink(procname, path, PATH_MAX);
|
|
if (res < 0) {
|
|
fuse_log(FUSE_LOG_WARNING, "%s: readlink failed: %m\n", __func__);
|
|
goto fail_noretry;
|
|
}
|
|
|
|
if (res >= PATH_MAX) {
|
|
fuse_log(FUSE_LOG_WARNING, "%s: readlink overflowed\n", __func__);
|
|
goto fail_noretry;
|
|
}
|
|
path[res] = '\0';
|
|
|
|
last = strrchr(path, '/');
|
|
if (last == NULL) {
|
|
/* Shouldn't happen */
|
|
fuse_log(
|
|
FUSE_LOG_WARNING,
|
|
"%s: INTERNAL ERROR: bad path read from proc\n", __func__);
|
|
goto fail_noretry;
|
|
}
|
|
if (last == path) {
|
|
p = &lo->root;
|
|
pthread_mutex_lock(&lo->mutex);
|
|
p->refcount++;
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
} else {
|
|
*last = '\0';
|
|
res = fstatat(AT_FDCWD, last == path ? "/" : path, &stat, 0);
|
|
if (res == -1) {
|
|
if (!retries) {
|
|
fuse_log(FUSE_LOG_WARNING,
|
|
"%s: failed to stat parent: %m\n", __func__);
|
|
}
|
|
goto fail;
|
|
}
|
|
p = lo_find(lo, &stat);
|
|
if (p == NULL) {
|
|
if (!retries) {
|
|
fuse_log(FUSE_LOG_WARNING,
|
|
"%s: failed to find parent\n", __func__);
|
|
}
|
|
goto fail;
|
|
}
|
|
}
|
|
last++;
|
|
res = fstatat(p->fd, last, &stat, AT_SYMLINK_NOFOLLOW);
|
|
if (res == -1) {
|
|
if (!retries) {
|
|
fuse_log(FUSE_LOG_WARNING,
|
|
"%s: failed to stat last\n", __func__);
|
|
}
|
|
goto fail_unref;
|
|
}
|
|
if (stat.st_dev != inode->dev || stat.st_ino != inode->ino) {
|
|
if (!retries) {
|
|
fuse_log(FUSE_LOG_WARNING,
|
|
"%s: failed to match last\n", __func__);
|
|
}
|
|
goto fail_unref;
|
|
}
|
|
*parent = p;
|
|
memmove(path, last, strlen(last) + 1);
|
|
|
|
return 0;
|
|
|
|
fail_unref:
|
|
unref_inode(lo, p, 1);
|
|
fail:
|
|
if (retries) {
|
|
retries--;
|
|
goto retry;
|
|
}
|
|
fail_noretry:
|
|
errno = EIO;
|
|
return -1;
|
|
}
|
|
|
|
static int utimensat_empty(struct lo_data *lo, struct lo_inode *inode,
|
|
const struct timespec *tv)
|
|
{
|
|
int res;
|
|
struct lo_inode *parent;
|
|
char path[PATH_MAX];
|
|
|
|
if (inode->is_symlink) {
|
|
res = utimensat(inode->fd, "", tv, AT_EMPTY_PATH);
|
|
if (res == -1 && errno == EINVAL) {
|
|
/* Sorry, no race free way to set times on symlink. */
|
|
if (lo->norace) {
|
|
errno = EPERM;
|
|
} else {
|
|
goto fallback;
|
|
}
|
|
}
|
|
return res;
|
|
}
|
|
sprintf(path, "/proc/self/fd/%i", inode->fd);
|
|
|
|
return utimensat(AT_FDCWD, path, tv, 0);
|
|
|
|
fallback:
|
|
res = lo_parent_and_name(lo, inode, path, &parent);
|
|
if (res != -1) {
|
|
res = utimensat(parent->fd, path, tv, AT_SYMLINK_NOFOLLOW);
|
|
unref_inode(lo, parent, 1);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
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, "/proc/self/fd/%i", ifd);
|
|
res = chmod(procname, attr->st_mode);
|
|
}
|
|
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) {
|
|
if (fi) {
|
|
res = ftruncate(fd, attr->st_size);
|
|
} else {
|
|
sprintf(procname, "/proc/self/fd/%i", ifd);
|
|
res = truncate(procname, attr->st_size);
|
|
}
|
|
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 {
|
|
res = utimensat_empty(lo, inode, tv);
|
|
}
|
|
if (res == -1) {
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
return lo_getattr(req, ino, fi);
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
static struct lo_inode *lo_find(struct lo_data *lo, struct stat *st)
|
|
{
|
|
struct lo_inode *p;
|
|
struct lo_inode *ret = NULL;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
for (p = lo->root.next; p != &lo->root; p = p->next) {
|
|
if (p->ino == st->st_ino && p->dev == st->st_dev) {
|
|
assert(p->refcount > 0);
|
|
ret = p;
|
|
ret->refcount++;
|
|
break;
|
|
}
|
|
}
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
|
|
memset(e, 0, sizeof(*e));
|
|
e->attr_timeout = lo->timeout;
|
|
e->entry_timeout = lo->timeout;
|
|
|
|
newfd = openat(lo_fd(req, parent), 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_data(req), &e->attr);
|
|
if (inode) {
|
|
close(newfd);
|
|
newfd = -1;
|
|
} else {
|
|
struct lo_inode *prev, *next;
|
|
|
|
saverr = ENOMEM;
|
|
inode = calloc(1, sizeof(struct lo_inode));
|
|
if (!inode) {
|
|
goto out_err;
|
|
}
|
|
|
|
inode->is_symlink = S_ISLNK(e->attr.st_mode);
|
|
inode->refcount = 1;
|
|
inode->fd = newfd;
|
|
inode->ino = e->attr.st_ino;
|
|
inode->dev = e->attr.st_dev;
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
inode->fuse_ino = lo_add_inode_mapping(req, inode);
|
|
prev = &lo->root;
|
|
next = prev->next;
|
|
next->prev = inode;
|
|
inode->next = next;
|
|
inode->prev = prev;
|
|
prev->next = inode;
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
}
|
|
e->ino = inode->fuse_ino;
|
|
|
|
if (lo_debug(req)) {
|
|
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);
|
|
}
|
|
return saverr;
|
|
}
|
|
|
|
static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
|
|
{
|
|
struct fuse_entry_param e;
|
|
int err;
|
|
|
|
if (lo_debug(req)) {
|
|
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_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 = ENOMEM;
|
|
|
|
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;
|
|
}
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n",
|
|
(unsigned long long)parent, name, (unsigned long long)e.ino);
|
|
}
|
|
|
|
fuse_reply_entry(req, &e);
|
|
return;
|
|
|
|
out:
|
|
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 int linkat_empty_nofollow(struct lo_data *lo, struct lo_inode *inode,
|
|
int dfd, const char *name)
|
|
{
|
|
int res;
|
|
struct lo_inode *parent;
|
|
char path[PATH_MAX];
|
|
|
|
if (inode->is_symlink) {
|
|
res = linkat(inode->fd, "", dfd, name, AT_EMPTY_PATH);
|
|
if (res == -1 && (errno == ENOENT || errno == EINVAL)) {
|
|
/* Sorry, no race free way to hard-link a symlink. */
|
|
if (lo->norace) {
|
|
errno = EPERM;
|
|
} else {
|
|
goto fallback;
|
|
}
|
|
}
|
|
return res;
|
|
}
|
|
|
|
sprintf(path, "/proc/self/fd/%i", inode->fd);
|
|
|
|
return linkat(AT_FDCWD, path, dfd, name, AT_SYMLINK_FOLLOW);
|
|
|
|
fallback:
|
|
res = lo_parent_and_name(lo, inode, path, &parent);
|
|
if (res != -1) {
|
|
res = linkat(parent->fd, path, dfd, name, 0);
|
|
unref_inode(lo, parent, 1);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
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 *inode;
|
|
struct fuse_entry_param e;
|
|
int saverr;
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
memset(&e, 0, sizeof(struct fuse_entry_param));
|
|
e.attr_timeout = lo->timeout;
|
|
e.entry_timeout = lo->timeout;
|
|
|
|
res = linkat_empty_nofollow(lo, inode, lo_fd(req, parent), name);
|
|
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->refcount++;
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
e.ino = inode->fuse_ino;
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n",
|
|
(unsigned long long)parent, name, (unsigned long long)e.ino);
|
|
}
|
|
|
|
fuse_reply_entry(req, &e);
|
|
return;
|
|
|
|
out_err:
|
|
saverr = errno;
|
|
fuse_reply_err(req, saverr);
|
|
}
|
|
|
|
static void lo_rmdir(fuse_req_t req, fuse_ino_t parent, const char *name)
|
|
{
|
|
int res;
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
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;
|
|
|
|
if (!is_safe_path_component(name) || !is_safe_path_component(newname)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
if (flags) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
res = renameat(lo_fd(req, parent), name, lo_fd(req, newparent), newname);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
static void lo_unlink(fuse_req_t req, fuse_ino_t parent, const char *name)
|
|
{
|
|
int res;
|
|
|
|
if (!is_safe_path_component(name)) {
|
|
fuse_reply_err(req, EINVAL);
|
|
return;
|
|
}
|
|
|
|
res = unlinkat(lo_fd(req, parent), name, 0);
|
|
|
|
fuse_reply_err(req, res == -1 ? errno : 0);
|
|
}
|
|
|
|
static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n)
|
|
{
|
|
if (!inode) {
|
|
return;
|
|
}
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
assert(inode->refcount >= n);
|
|
inode->refcount -= n;
|
|
if (!inode->refcount) {
|
|
struct lo_inode *prev, *next;
|
|
|
|
prev = inode->prev;
|
|
next = inode->next;
|
|
next->prev = prev;
|
|
prev->next = next;
|
|
|
|
lo_map_remove(&lo->ino_map, inode->fuse_ino);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
close(inode->fd);
|
|
free(inode);
|
|
} else {
|
|
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;
|
|
}
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG, " forget %lli %lli -%lli\n",
|
|
(unsigned long long)ino, (unsigned long long)inode->refcount,
|
|
(unsigned long long)nlookup);
|
|
}
|
|
|
|
unref_inode(lo, inode, nlookup);
|
|
}
|
|
|
|
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 {
|
|
DIR *dp;
|
|
struct dirent *entry;
|
|
off_t offset;
|
|
};
|
|
|
|
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);
|
|
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;
|
|
|
|
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->keep_cache = 1;
|
|
}
|
|
fuse_reply_open(req, fi);
|
|
return;
|
|
|
|
out_errno:
|
|
error = errno;
|
|
out_err:
|
|
if (d) {
|
|
if (d->dp) {
|
|
closedir(d->dp);
|
|
}
|
|
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_dirp *d;
|
|
char *buf = NULL;
|
|
char *p;
|
|
size_t rem = size;
|
|
int err = ENOMEM;
|
|
|
|
(void)ino;
|
|
|
|
d = lo_dirp(req, fi);
|
|
if (!d) {
|
|
goto error;
|
|
}
|
|
|
|
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;
|
|
if (plus) {
|
|
struct fuse_entry_param e;
|
|
if (is_dot_or_dotdot(name)) {
|
|
e = (struct fuse_entry_param){
|
|
.attr.st_ino = d->entry->d_ino,
|
|
.attr.st_mode = d->entry->d_type << 12,
|
|
};
|
|
} else {
|
|
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 {
|
|
struct stat st = {
|
|
.st_ino = d->entry->d_ino,
|
|
.st_mode = d->entry->d_type << 12,
|
|
};
|
|
entsize = fuse_add_direntry(req, p, rem, name, &st, 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:
|
|
/*
|
|
* 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_dirp *d;
|
|
|
|
(void)ino;
|
|
|
|
d = lo_dirp(req, fi);
|
|
if (!d) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
lo_map_remove(&lo->dirp_map, fi->fh);
|
|
pthread_mutex_unlock(&lo->mutex);
|
|
|
|
closedir(d->dp);
|
|
free(d);
|
|
fuse_reply_err(req, 0);
|
|
}
|
|
|
|
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 fuse_entry_param e;
|
|
int err;
|
|
struct lo_cred old = {};
|
|
|
|
if (lo_debug(req)) {
|
|
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;
|
|
}
|
|
|
|
err = lo_change_cred(req, &old);
|
|
if (err) {
|
|
goto out;
|
|
}
|
|
|
|
fd = openat(lo_fd(req, parent), 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);
|
|
fuse_reply_err(req, ENOMEM);
|
|
return;
|
|
}
|
|
|
|
fi->fh = fh;
|
|
err = lo_do_lookup(req, parent, name, &e);
|
|
}
|
|
if (lo->cache == CACHE_NEVER) {
|
|
fi->direct_io = 1;
|
|
} else if (lo->cache == CACHE_ALWAYS) {
|
|
fi->keep_cache = 1;
|
|
}
|
|
|
|
out:
|
|
if (err) {
|
|
fuse_reply_err(req, err);
|
|
} else {
|
|
fuse_reply_create(req, &e, fi);
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|
|
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);
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_open(ino=%" PRIu64 ", flags=%d)\n", ino,
|
|
fi->flags);
|
|
}
|
|
|
|
/*
|
|
* With writeback cache, kernel may send read requests even
|
|
* when userspace opened write-only
|
|
*/
|
|
if (lo->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 (lo->writeback && (fi->flags & O_APPEND)) {
|
|
fi->flags &= ~O_APPEND;
|
|
}
|
|
|
|
sprintf(buf, "/proc/self/fd/%i", lo_fd(req, ino));
|
|
fd = open(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_NEVER) {
|
|
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);
|
|
int fd;
|
|
|
|
(void)ino;
|
|
|
|
fd = lo_fi_fd(req, fi);
|
|
|
|
pthread_mutex_lock(&lo->mutex);
|
|
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;
|
|
res = close(dup(lo_fi_fd(req, fi)));
|
|
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;
|
|
(void)ino;
|
|
int fd;
|
|
char *buf;
|
|
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_fsync(ino=%" PRIu64 ", fi=0x%p)\n", ino,
|
|
(void *)fi);
|
|
|
|
if (!fi) {
|
|
res = asprintf(&buf, "/proc/self/fd/%i", lo_fd(req, ino));
|
|
if (res == -1) {
|
|
return (void)fuse_reply_err(req, errno);
|
|
}
|
|
|
|
fd = open(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);
|
|
|
|
if (lo_debug(req)) {
|
|
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));
|
|
|
|
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;
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_write(ino=%" PRIu64 ", size=%zd, off=%lu)\n", ino,
|
|
out_buf.buf[0].size, (unsigned long)off);
|
|
}
|
|
|
|
res = fuse_buf_copy(&out_buf, in_buf);
|
|
if (res < 0) {
|
|
fuse_reply_err(req, -res);
|
|
} else {
|
|
fuse_reply_write(req, (size_t)res);
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
char *value = NULL;
|
|
char procname[64];
|
|
struct lo_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_getxattr(ino=%" PRIu64 ", name=%s size=%zd)\n", ino, name,
|
|
size);
|
|
}
|
|
|
|
if (inode->is_symlink) {
|
|
/* Sorry, no race free way to getxattr on symlink. */
|
|
saverr = EPERM;
|
|
goto out;
|
|
}
|
|
|
|
sprintf(procname, "/proc/self/fd/%i", inode->fd);
|
|
|
|
if (size) {
|
|
value = malloc(size);
|
|
if (!value) {
|
|
goto out_err;
|
|
}
|
|
|
|
ret = getxattr(procname, name, value, size);
|
|
if (ret == -1) {
|
|
goto out_err;
|
|
}
|
|
saverr = 0;
|
|
if (ret == 0) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_reply_buf(req, value, ret);
|
|
} else {
|
|
ret = getxattr(procname, name, NULL, 0);
|
|
if (ret == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
fuse_reply_xattr(req, ret);
|
|
}
|
|
out_free:
|
|
free(value);
|
|
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)
|
|
{
|
|
char *value = NULL;
|
|
char procname[64];
|
|
struct lo_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_listxattr(ino=%" PRIu64 ", size=%zd)\n",
|
|
ino, size);
|
|
}
|
|
|
|
if (inode->is_symlink) {
|
|
/* Sorry, no race free way to listxattr on symlink. */
|
|
saverr = EPERM;
|
|
goto out;
|
|
}
|
|
|
|
sprintf(procname, "/proc/self/fd/%i", inode->fd);
|
|
|
|
if (size) {
|
|
value = malloc(size);
|
|
if (!value) {
|
|
goto out_err;
|
|
}
|
|
|
|
ret = listxattr(procname, value, size);
|
|
if (ret == -1) {
|
|
goto out_err;
|
|
}
|
|
saverr = 0;
|
|
if (ret == 0) {
|
|
goto out;
|
|
}
|
|
|
|
fuse_reply_buf(req, value, ret);
|
|
} else {
|
|
ret = listxattr(procname, NULL, 0);
|
|
if (ret == -1) {
|
|
goto out_err;
|
|
}
|
|
|
|
fuse_reply_xattr(req, ret);
|
|
}
|
|
out_free:
|
|
free(value);
|
|
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_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG,
|
|
"lo_setxattr(ino=%" PRIu64 ", name=%s value=%s size=%zd)\n",
|
|
ino, name, value, size);
|
|
}
|
|
|
|
if (inode->is_symlink) {
|
|
/* Sorry, no race free way to setxattr on symlink. */
|
|
saverr = EPERM;
|
|
goto out;
|
|
}
|
|
|
|
sprintf(procname, "/proc/self/fd/%i", inode->fd);
|
|
|
|
ret = setxattr(procname, name, value, size, flags);
|
|
saverr = ret == -1 ? errno : 0;
|
|
|
|
out:
|
|
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_inode *inode;
|
|
ssize_t ret;
|
|
int saverr;
|
|
|
|
inode = lo_inode(req, ino);
|
|
if (!inode) {
|
|
fuse_reply_err(req, EBADF);
|
|
return;
|
|
}
|
|
|
|
saverr = ENOSYS;
|
|
if (!lo_data(req)->xattr) {
|
|
goto out;
|
|
}
|
|
|
|
if (lo_debug(req)) {
|
|
fuse_log(FUSE_LOG_DEBUG, "lo_removexattr(ino=%" PRIu64 ", name=%s)\n",
|
|
ino, name);
|
|
}
|
|
|
|
if (inode->is_symlink) {
|
|
/* Sorry, no race free way to setxattr on symlink. */
|
|
saverr = EPERM;
|
|
goto out;
|
|
}
|
|
|
|
sprintf(procname, "/proc/self/fd/%i", inode->fd);
|
|
|
|
ret = removexattr(procname, name);
|
|
saverr = ret == -1 ? errno : 0;
|
|
|
|
out:
|
|
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 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,
|
|
.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,
|
|
};
|
|
|
|
/* Print vhost-user.json backend program capabilities */
|
|
static void print_capabilities(void)
|
|
{
|
|
printf("{\n");
|
|
printf(" \"type\": \"fs\"\n");
|
|
printf("}\n");
|
|
}
|
|
|
|
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 };
|
|
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.root.next = lo.root.prev = &lo.root;
|
|
lo.root.fd = -1;
|
|
lo.root.fuse_ino = FUSE_ROOT_ID;
|
|
lo.cache = CACHE_NORMAL;
|
|
|
|
/*
|
|
* 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) {
|
|
return 1;
|
|
}
|
|
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) {
|
|
return 1;
|
|
}
|
|
|
|
lo.debug = opts.debug;
|
|
lo.root.refcount = 2;
|
|
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 = "/";
|
|
}
|
|
lo.root.is_symlink = false;
|
|
if (!lo.timeout_set) {
|
|
switch (lo.cache) {
|
|
case CACHE_NEVER:
|
|
lo.timeout = 0.0;
|
|
break;
|
|
|
|
case CACHE_NORMAL:
|
|
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);
|
|
}
|
|
|
|
lo.root.fd = open(lo.source, O_PATH);
|
|
if (lo.root.fd == -1) {
|
|
fuse_log(FUSE_LOG_ERR, "open(\"%s\", O_PATH): %m\n", lo.source);
|
|
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);
|
|
|
|
/* Block until ctrl+c or fusermount -u */
|
|
ret = virtio_loop(se);
|
|
|
|
fuse_session_unmount(se);
|
|
err_out3:
|
|
fuse_remove_signal_handlers(se);
|
|
err_out2:
|
|
fuse_session_destroy(se);
|
|
err_out1:
|
|
fuse_opt_free_args(&args);
|
|
|
|
lo_map_destroy(&lo.fd_map);
|
|
lo_map_destroy(&lo.dirp_map);
|
|
lo_map_destroy(&lo.ino_map);
|
|
|
|
if (lo.root.fd >= 0) {
|
|
close(lo.root.fd);
|
|
}
|
|
|
|
return ret ? 1 : 0;
|
|
}
|