flatpak-builder/document-portal/xdp-fuse.c

1788 lines
40 KiB
C

#include "config.h"
#define FUSE_USE_VERSION 26
#include <glib-unix.h>
#include <fuse_lowlevel.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <assert.h>
#include <glib/gprintf.h>
#include <gio/gio.h>
#include "xdp-error.h"
#include "xdp-fuse.h"
/* Layout:
"/ (STD_DIRS:1)
"by-app/" (STD_DIRS:2)
"org.gnome.gedit/" (APP_DIR:app id)
"$id/" (APP_DOC_DIR:app_id<<32|doc_id)
<same as DOC_DIR>
"in-homedir/" (APP_DOC_DIR:1)
"$id" (DOC_DIR:doc_idid)
$basename (DOC_FILE:doc_id)
$tmpfile (TMPFILE:tmp_id)
*/
#define BY_APP_INO 2
#define IN_HOMEDIR_APP_ID 1
#define NON_DOC_DIR_PERMS 0500
#define DOC_DIR_PERMS 0700
/* The (fake) directories don't really change */
#define DIRS_ATTR_CACHE_TIME 60.0
/* We pretend that the file is hardlinked. This causes most apps to do
a truncating overwrite, which suits us better, as we do the atomic
rename ourselves anyway. This way we don't weirdly change the inode
after the rename. */
#define DOC_FILE_NLINK 2
typedef enum {
STD_DIRS_INO_CLASS,
DOC_DIR_INO_CLASS,
DOC_FILE_INO_CLASS,
TMPFILE_INO_CLASS,
APP_DIR_INO_CLASS,
APP_DOC_DIR_INO_CLASS,
} XdpInodeClass;
#define BY_APP_NAME "by-app"
#define IN_HOMEDIR_NAME "in-homedir"
static XdpDocDb *db;
static GHashTable *app_name_to_id;
static GHashTable *app_id_to_name;
static guint32 next_app_id;
static guint32 next_tmp_id;
typedef struct
{
guint64 parent_inode;
char *name;
char *backing_path;
guint32 tmp_id;
} XdpTmp;
typedef struct
{
int fd;
fuse_ino_t inode;
int trunc_fd;
char *trunc_path;
char *real_path;
gboolean truncated;
gboolean readonly;
guint32 tmp_id;
} XdpFh;
static GList *tmp_files = NULL;
static GList *open_files = NULL;
static XdpTmp *
find_tmp_by_name (guint64 parent_inode,
const char *name)
{
GList *l;
for (l = tmp_files; l != NULL; l = l->next)
{
XdpTmp *tmp = l->data;
if (tmp->parent_inode == parent_inode &&
strcmp (tmp->name, name) == 0)
return tmp;
}
return NULL;
}
static XdpTmp *
find_tmp_by_id (guint32 tmp_id)
{
GList *l;
for (l = tmp_files; l != NULL; l = l->next)
{
XdpTmp *tmp = l->data;
if (tmp->tmp_id == tmp_id)
return tmp;
}
return NULL;
}
static XdpInodeClass
get_class (guint64 inode)
{
return (inode >> (64-8)) & 0xff;
}
static guint64
get_class_ino (guint64 inode)
{
return inode & ((1L << (64-8)) - 1);
}
static guint32
get_app_id_from_app_doc_ino (guint64 inode)
{
return inode >> 32;
}
static guint32
get_doc_id_from_app_doc_ino (guint64 inode)
{
return inode & 0xffffffff;
}
static guint64
make_inode (XdpInodeClass class, guint64 inode)
{
return ((guint64)class) << (64-8) | (inode & 0xffffffffffffff);
}
static guint64
make_app_doc_dir_inode (guint32 app_id, guint32 doc_id)
{
return make_inode (APP_DOC_DIR_INO_CLASS,
((guint64)app_id << 32) | (guint64)doc_id);
}
static gboolean
name_looks_like_id (const char *name)
{
int i;
/* No zeros in front, we need canonical form */
if (name[0] == '0')
return FALSE;
for (i = 0; i < 8; i++)
{
char c = name[i];
if (c == 0)
break;
if (!g_ascii_isdigit(c) &&
!(c >= 'a' && c <= 'f'))
return FALSE;
}
if (name[i] != 0)
return FALSE;
return TRUE;
}
static guint32
get_app_id_from_name (const char *name)
{
guint32 id;
char *myname;
id = GPOINTER_TO_UINT (g_hash_table_lookup (app_name_to_id, name));
if (id != 0)
return id;
id = next_app_id++;
/* We rely this to not overwrap into the high byte in the inode */
g_assert (id < 0x00ffffff);
myname = g_strdup (name);
g_hash_table_insert (app_name_to_id, myname, GUINT_TO_POINTER (id));
g_hash_table_insert (app_id_to_name, GUINT_TO_POINTER (id), myname);
return id;
}
static const char *
get_app_name_from_id (guint32 id)
{
return g_hash_table_lookup (app_id_to_name, GUINT_TO_POINTER (id));
}
static void
fill_app_name_hash (void)
{
char **keys;
int i;
keys = xdp_doc_db_list_apps (db);
for (i = 0; keys[i] != NULL; i++)
get_app_id_from_name (keys[i]);
g_strfreev (keys);
}
static XdpFh *
xdp_fh_new (fuse_ino_t inode, struct fuse_file_info *fi, int fd, XdpTmp *tmp)
{
XdpFh *fh = g_new0 (XdpFh, 1);
fh->inode = inode;
fh->fd = fd;
if (tmp)
fh->tmp_id = tmp->tmp_id;
fh->trunc_fd = -1;
open_files = g_list_prepend (open_files, fh);
fi->fh = (gsize)fh;
return fh;
}
static void
xdp_fh_free (XdpFh *fh)
{
open_files = g_list_remove (open_files, fh);
if (fh->truncated)
{
fsync (fh->trunc_fd);
if (rename (fh->trunc_path, fh->real_path) != 0)
g_warning ("Unable to replace truncated document");
}
else if (fh->trunc_path)
unlink (fh->trunc_path);
if (fh->fd >= 0)
close (fh->fd);
if (fh->trunc_fd >= 0)
close (fh->trunc_fd);
g_clear_pointer (&fh->trunc_path, g_free);
g_clear_pointer (&fh->real_path, g_free);
g_free (fh);
}
static int
xdp_fh_get_fd (XdpFh *fh)
{
if (fh->truncated)
return fh->trunc_fd;
else
return fh->fd;
}
static int
get_user_perms (const struct stat *stbuf)
{
/* Strip out exec and setuid bits */
return stbuf->st_mode & 0666;
}
static double
get_attr_cache_time (int st_mode)
{
if (S_ISDIR (st_mode))
return DIRS_ATTR_CACHE_TIME;
return 0.0;
}
static double
get_entry_cache_time (int st_mode)
{
if (S_ISDIR (st_mode))
return DIRS_ATTR_CACHE_TIME;
return 1.0;
}
static gboolean
app_can_see_doc (GVariant *doc, guint32 app_id)
{
const char *app_name = get_app_name_from_id (app_id);
if (app_name != NULL &&
xdp_doc_has_permissions (doc, app_name, XDP_PERMISSION_FLAGS_READ))
return TRUE;
if (app_id == IN_HOMEDIR_APP_ID)
{
g_autofree char *path = xdp_doc_dup_path (doc);
if (g_str_has_prefix (path, g_get_home_dir ()))
return TRUE;
}
return FALSE;
}
static int
xdp_stat (fuse_ino_t ino,
struct stat *stbuf,
GVariant **doc_out)
{
XdpInodeClass class = get_class (ino);
guint64 class_ino = get_class_ino (ino);
g_autoptr (GVariant) doc = NULL;
g_autofree char *path = NULL;
struct stat tmp_stbuf;
XdpTmp *tmp;
stbuf->st_ino = ino;
switch (class)
{
case STD_DIRS_INO_CLASS:
switch (class_ino)
{
case FUSE_ROOT_ID:
stbuf->st_mode = S_IFDIR | NON_DOC_DIR_PERMS;
stbuf->st_nlink = 2;
break;
case BY_APP_INO:
stbuf->st_mode = S_IFDIR | NON_DOC_DIR_PERMS;
stbuf->st_nlink = 2;
break;
default:
return ENOENT;
}
break;
case APP_DIR_INO_CLASS:
if (class_ino != IN_HOMEDIR_APP_ID && get_app_name_from_id (class_ino) == 0)
return ENOENT;
stbuf->st_mode = S_IFDIR | NON_DOC_DIR_PERMS;
stbuf->st_nlink = 2;
break;
case APP_DOC_DIR_INO_CLASS:
{
guint32 app_id = get_app_id_from_app_doc_ino (class_ino);
guint32 doc_id = get_doc_id_from_app_doc_ino (class_ino);
doc = xdp_doc_db_lookup_doc (db, doc_id);
if (doc == NULL ||
!app_can_see_doc (doc, app_id))
return ENOENT;
stbuf->st_mode = S_IFDIR | DOC_DIR_PERMS;
stbuf->st_nlink = 2;
break;
}
case DOC_DIR_INO_CLASS:
doc = xdp_doc_db_lookup_doc (db, class_ino);
if (doc == NULL)
return ENOENT;
stbuf->st_mode = S_IFDIR | DOC_DIR_PERMS;
stbuf->st_nlink = 2;
break;
case DOC_FILE_INO_CLASS:
doc = xdp_doc_db_lookup_doc (db, class_ino);
if (doc == NULL)
return ENOENT;
stbuf->st_nlink = DOC_FILE_NLINK;
path = xdp_doc_dup_path (doc);
if (stat (path, &tmp_stbuf) != 0)
return ENOENT;
stbuf->st_mode = S_IFREG | get_user_perms (&tmp_stbuf);
stbuf->st_size = tmp_stbuf.st_size;
stbuf->st_uid = tmp_stbuf.st_uid;
stbuf->st_gid = tmp_stbuf.st_gid;
stbuf->st_blksize = tmp_stbuf.st_blksize;
stbuf->st_blocks = tmp_stbuf.st_blocks;
stbuf->st_atim = tmp_stbuf.st_atim;
stbuf->st_mtim = tmp_stbuf.st_mtim;
stbuf->st_ctim = tmp_stbuf.st_ctim;
break;
case TMPFILE_INO_CLASS:
tmp = find_tmp_by_id (class_ino);
if (tmp == NULL)
return ENOENT;
stbuf->st_mode = S_IFREG;
stbuf->st_nlink = DOC_FILE_NLINK;
if (stat (tmp->backing_path, &tmp_stbuf) != 0)
return ENOENT;
stbuf->st_mode = S_IFREG | get_user_perms (&tmp_stbuf);
stbuf->st_size = tmp_stbuf.st_size;
stbuf->st_uid = tmp_stbuf.st_uid;
stbuf->st_gid = tmp_stbuf.st_gid;
stbuf->st_blksize = tmp_stbuf.st_blksize;
stbuf->st_blocks = tmp_stbuf.st_blocks;
stbuf->st_atim = tmp_stbuf.st_atim;
stbuf->st_mtim = tmp_stbuf.st_mtim;
stbuf->st_ctim = tmp_stbuf.st_ctim;
break;
default:
return ENOENT;
}
if (doc && doc_out)
*doc_out = g_steal_pointer (&doc);
return 0;
}
static int
xdp_fstat (XdpFh *fh,
struct stat *stbuf)
{
struct stat tmp_stbuf;
int fd;
fd = xdp_fh_get_fd (fh);
if (fd < 0)
return -ENOSYS;
if (fstat (fd, &tmp_stbuf) != 0)
return -errno;
stbuf->st_nlink = DOC_FILE_NLINK;
stbuf->st_mode = S_IFREG | get_user_perms (&tmp_stbuf);
stbuf->st_size = tmp_stbuf.st_size;
stbuf->st_uid = tmp_stbuf.st_uid;
stbuf->st_gid = tmp_stbuf.st_gid;
stbuf->st_blksize = tmp_stbuf.st_blksize;
stbuf->st_blocks = tmp_stbuf.st_blocks;
stbuf->st_atim = tmp_stbuf.st_atim;
stbuf->st_mtim = tmp_stbuf.st_mtim;
stbuf->st_ctim = tmp_stbuf.st_ctim;
return 0;
}
static void
xdp_fuse_getattr (fuse_req_t req,
fuse_ino_t ino,
struct fuse_file_info *fi)
{
struct stat stbuf = { 0 };
GList *l;
int res;
g_debug ("xdp_fuse_getattr %lx (fi=%p)", ino, fi);
/* Fuse passes fi in to verify EOF during read/write/seek, but not during fstat */
if (fi != NULL)
{
XdpFh *fh = (gpointer)fi->fh;
res = xdp_fstat (fh, &stbuf);
if (res == 0)
{
fuse_reply_attr (req, &stbuf, get_attr_cache_time (stbuf.st_mode));
return;
}
}
for (l = open_files; l != NULL; l = l->next)
{
XdpFh *fh = l->data;
if (fh->inode == ino)
{
res = xdp_fstat (fh, &stbuf);
if (res == 0)
{
fuse_reply_attr (req, &stbuf, get_attr_cache_time (stbuf.st_mode));
return;
}
}
}
if ((res = xdp_stat (ino, &stbuf, NULL)) != 0)
fuse_reply_err (req, res);
else
fuse_reply_attr (req, &stbuf, get_attr_cache_time (stbuf.st_mode));
}
static int
xdp_lookup (fuse_ino_t parent,
const char *name,
fuse_ino_t *inode,
struct stat *stbuf,
GVariant **doc_out,
XdpTmp **tmp_out)
{
XdpInodeClass parent_class = get_class (parent);
guint64 parent_class_ino = get_class_ino (parent);
g_autoptr (GVariant) doc = NULL;
XdpTmp *tmp;
if (doc_out)
*doc_out = NULL;
if (tmp_out)
*tmp_out = NULL;
switch (parent_class)
{
case STD_DIRS_INO_CLASS:
switch (parent_class_ino)
{
case FUSE_ROOT_ID:
if (strcmp (name, BY_APP_NAME) == 0)
{
*inode = make_inode (STD_DIRS_INO_CLASS, BY_APP_INO);
if (xdp_stat (*inode, stbuf, NULL) == 0)
return 0;
}
else if (strcmp (name, IN_HOMEDIR_NAME) == 0)
{
*inode = make_inode (APP_DIR_INO_CLASS, IN_HOMEDIR_APP_ID);
if (xdp_stat (*inode, stbuf, NULL) == 0)
return 0;
}
else if (name_looks_like_id (name))
{
*inode = make_inode (DOC_DIR_INO_CLASS,
xdb_doc_id_from_name (name));
if (xdp_stat (*inode, stbuf, NULL) == 0)
return 0;
}
break;
case BY_APP_INO:
if (g_dbus_is_name (name) && !g_dbus_is_unique_name (name))
{
guint32 app_id = get_app_id_from_name (name);
*inode = make_inode (APP_DIR_INO_CLASS, app_id);
if (xdp_stat (*inode, stbuf, NULL) == 0)
return 0;
}
break;
default:
break;
}
break;
case APP_DIR_INO_CLASS:
{
if (name_looks_like_id (name))
{
*inode = make_app_doc_dir_inode (parent_class_ino,
xdb_doc_id_from_name (name));
if (xdp_stat (*inode, stbuf, NULL) == 0)
return 0;
}
}
break;
case APP_DOC_DIR_INO_CLASS:
case DOC_DIR_INO_CLASS:
if (parent_class == APP_DOC_DIR_INO_CLASS)
doc = xdp_doc_db_lookup_doc (db, get_doc_id_from_app_doc_ino (parent_class_ino));
else
doc = xdp_doc_db_lookup_doc (db, parent_class_ino);
if (doc != NULL)
{
g_autofree char *basename = xdp_doc_dup_basename (doc);
if (strcmp (name, basename) == 0)
{
*inode = make_inode (DOC_FILE_INO_CLASS, parent_class_ino);
if (xdp_stat (*inode, stbuf, NULL) == 0)
{
if (doc_out)
*doc_out = g_steal_pointer (&doc);
return 0;
}
break;
}
}
tmp = find_tmp_by_name (parent, name);
if (tmp != NULL)
{
*inode = make_inode (TMPFILE_INO_CLASS, tmp->tmp_id);
if (xdp_stat (*inode, stbuf, NULL) == 0)
{
if (doc_out)
*doc_out = g_steal_pointer (&doc);
if (tmp_out)
*tmp_out = tmp;
return 0;
}
break;
}
break;
case TMPFILE_INO_CLASS:
case DOC_FILE_INO_CLASS:
return ENOTDIR;
default:
break;
}
return ENOENT;
}
static void
xdp_fuse_lookup (fuse_req_t req,
fuse_ino_t parent,
const char *name)
{
struct fuse_entry_param e = {0};
int res;
g_debug ("xdp_fuse_lookup %lx/%s", parent, name);
memset (&e, 0, sizeof(e));
res = xdp_lookup (parent, name, &e.ino, &e.attr, NULL, NULL);
if (res == 0)
{
e.attr_timeout = get_attr_cache_time (e.attr.st_mode);
e.entry_timeout = get_entry_cache_time (e.attr.st_mode);
fuse_reply_entry (req, &e);
}
else
{
fuse_reply_err (req, res);
}
}
struct dirbuf {
char *p;
size_t size;
};
static void
dirbuf_add (fuse_req_t req,
struct dirbuf *b,
const char *name,
fuse_ino_t ino)
{
struct stat stbuf;
size_t oldsize = b->size;
b->size += fuse_add_direntry (req, NULL, 0, name, NULL, 0);
b->p = (char *) g_realloc (b->p, b->size);
memset (&stbuf, 0, sizeof (stbuf));
stbuf.st_ino = ino;
fuse_add_direntry (req, b->p + oldsize,
b->size - oldsize,
name, &stbuf,
b->size);
}
static void
dirbuf_add_docs (fuse_req_t req,
struct dirbuf *b,
guint32 app_id)
{
g_autofree guint32 *docs = NULL;
guint64 inode;
int i;
g_autofree char *doc_name = NULL;
docs = xdp_doc_db_list_docs (db);
for (i = 0; docs[i] != 0; i++)
{
if (app_id)
{
g_autoptr(GVariant) doc = xdp_doc_db_lookup_doc (db, docs[i]);
if (doc == NULL ||
!app_can_see_doc (doc, app_id))
continue;
}
if (app_id)
inode = make_app_doc_dir_inode (app_id, docs[i]);
else
inode = make_inode (DOC_DIR_INO_CLASS, docs[i]);
doc_name = xdb_doc_name_from_id (docs[i]);
dirbuf_add (req, b, doc_name, inode);
}
}
static void
dirbuf_add_doc_file (fuse_req_t req,
struct dirbuf *b,
GVariant *doc,
guint32 doc_id)
{
struct stat tmp_stbuf;
g_autofree char *path = xdp_doc_dup_path (doc);
g_autofree char *basename = xdp_doc_dup_basename (doc);
if (stat (path, &tmp_stbuf) == 0)
dirbuf_add (req, b, basename,
make_inode (DOC_FILE_INO_CLASS, doc_id));
}
static void
dirbuf_add_tmp_files (fuse_req_t req,
struct dirbuf *b,
guint64 dir_inode)
{
GList *l;
for (l = tmp_files; l != NULL; l = l->next)
{
XdpTmp *tmp = l->data;
if (tmp->parent_inode == dir_inode)
dirbuf_add (req, b, tmp->name,
make_inode (TMPFILE_INO_CLASS, tmp->tmp_id));
}
}
static int
reply_buf_limited (fuse_req_t req,
const char *buf,
size_t bufsize,
off_t off,
size_t maxsize)
{
if (off < bufsize)
return fuse_reply_buf (req, buf + off,
MIN (bufsize - off, maxsize));
else
return fuse_reply_buf (req, NULL, 0);
}
static void
xdp_fuse_readdir (fuse_req_t req, fuse_ino_t ino, size_t size,
off_t off, struct fuse_file_info *fi)
{
struct dirbuf *b = (struct dirbuf *)(fi->fh);
reply_buf_limited (req, b->p, b->size, off, size);
}
static void
xdp_fuse_opendir (fuse_req_t req,
fuse_ino_t ino,
struct fuse_file_info *fi)
{
struct stat stbuf = {0};
struct dirbuf b = {0};
XdpInodeClass class;
guint64 class_ino;
g_autoptr (GVariant) doc = NULL;
g_autofree char *basename = NULL;
int res;
g_debug ("xdp_fuse_opendir %lx", ino);
if ((res = xdp_stat (ino, &stbuf, &doc)) != 0)
{
fuse_reply_err (req, res);
return;
}
if ((stbuf.st_mode & S_IFMT) != S_IFDIR)
{
fuse_reply_err (req, ENOTDIR);
return;
}
class = get_class (ino);
class_ino = get_class_ino (ino);
switch (class)
{
case STD_DIRS_INO_CLASS:
switch (class_ino)
{
case FUSE_ROOT_ID:
dirbuf_add (req, &b, ".", FUSE_ROOT_ID);
dirbuf_add (req, &b, "..", FUSE_ROOT_ID);
dirbuf_add (req, &b, BY_APP_NAME,
make_inode (STD_DIRS_INO_CLASS, BY_APP_INO));
dirbuf_add (req, &b, IN_HOMEDIR_NAME,
make_inode (APP_DIR_INO_CLASS, IN_HOMEDIR_APP_ID));
dirbuf_add_docs (req, &b, 0);
break;
case BY_APP_INO:
dirbuf_add (req, &b, ".", ino);
dirbuf_add (req, &b, "..", FUSE_ROOT_ID);
/* Update for any possible new app */
fill_app_name_hash ();
{
GHashTableIter iter;
gpointer key, value;
g_hash_table_iter_init (&iter, app_name_to_id);
while (g_hash_table_iter_next (&iter, &key, &value))
{
const char *name = key;
guint32 id = GPOINTER_TO_UINT(value);
dirbuf_add (req, &b, name,
make_inode (APP_DIR_INO_CLASS, id));
}
}
break;
default:
break;
}
break;
case APP_DIR_INO_CLASS:
{
dirbuf_add (req, &b, ".", ino);
dirbuf_add (req, &b, "..", make_inode (STD_DIRS_INO_CLASS, BY_APP_INO));
dirbuf_add_docs (req, &b, class_ino);
break;
}
break;
case DOC_DIR_INO_CLASS:
dirbuf_add (req, &b, ".", ino);
dirbuf_add (req, &b, "..", FUSE_ROOT_ID);
dirbuf_add_doc_file (req, &b, doc, class_ino);
dirbuf_add_tmp_files (req, &b, ino);
break;
case APP_DOC_DIR_INO_CLASS:
dirbuf_add (req, &b, ".", ino);
dirbuf_add (req, &b, "..", make_inode (APP_DIR_INO_CLASS,
get_app_id_from_app_doc_ino (class_ino)));
dirbuf_add_doc_file (req, &b, doc,
get_doc_id_from_app_doc_ino (class_ino));
dirbuf_add_tmp_files (req, &b, ino);
break;
case DOC_FILE_INO_CLASS:
case TMPFILE_INO_CLASS:
/* These should have returned ENOTDIR above */
default:
break;
}
if (b.p == NULL)
fuse_reply_err (req, EIO);
else
{
fi->fh = (gsize)g_memdup (&b, sizeof (b));
if (fuse_reply_open (req, fi) == -ENOENT)
{
g_free (b.p);
g_free ((gpointer)(fi->fh));
}
}
}
static void
xdp_fuse_releasedir (fuse_req_t req,
fuse_ino_t ino,
struct fuse_file_info *fi)
{
struct dirbuf *b = (struct dirbuf *)(fi->fh);
g_free (b->p);
g_free (b);
fuse_reply_err (req, 0);
}
static int
get_open_flags (struct fuse_file_info *fi)
{
/* TODO: Maybe limit the flags set more */
return fi->flags & ~(O_EXCL|O_CREAT);
}
static char *
create_tmp_for_doc (GVariant *doc, int flags, int *fd_out)
{
g_autofree char *dirname = xdp_doc_dup_dirname (doc);
g_autofree char *basename = xdp_doc_dup_basename (doc);
g_autofree char *template = g_strconcat (dirname, "/.", basename, ".XXXXXX", NULL);
int fd;
fd = g_mkstemp_full (template, flags, 0600);
if (fd == -1)
return NULL;
*fd_out = fd;
return g_steal_pointer (&template);
}
static XdpTmp *
tmpfile_new (fuse_ino_t parent,
const char *name,
GVariant *doc,
int flags,
int *fd_out)
{
XdpTmp *tmp;
g_autofree char *path = NULL;
int fd;
path = create_tmp_for_doc (doc, flags, &fd);
if (path == NULL)
return NULL;
tmp = g_new0 (XdpTmp, 1);
tmp->parent_inode = parent;
tmp->name = g_strdup (name);
tmp->backing_path = g_steal_pointer (&path);
tmp->tmp_id = next_tmp_id++;
if (fd_out)
*fd_out = fd;
else
close (fd);
tmp_files = g_list_prepend (tmp_files, tmp);
return tmp;
}
static void
tmpfile_free (XdpTmp *tmp)
{
GList *l;
tmp_files = g_list_remove (tmp_files, tmp);
for (l = open_files; l != NULL; l = l->next)
{
XdpFh *fh = l->data;
if (fh->tmp_id == tmp->tmp_id)
fh->tmp_id = 0;
}
if (tmp->backing_path)
unlink (tmp->backing_path);
g_free (tmp->name);
g_free (tmp->backing_path);
g_free (tmp);
}
static void
xdp_fuse_open (fuse_req_t req,
fuse_ino_t ino,
struct fuse_file_info *fi)
{
XdpInodeClass class = get_class (ino);
guint64 class_ino = get_class_ino (ino);
struct stat stbuf = {0};
g_autoptr (GVariant) doc = NULL;
g_autofree char *path = NULL;
XdpTmp *tmp;
int fd, res;
XdpFh *fh;
g_debug ("xdp_fuse_open %lx", ino);
if ((res = xdp_stat (ino, &stbuf, &doc)) != 0)
{
fuse_reply_err (req, res);
return;
}
if ((stbuf.st_mode & S_IFMT) != S_IFREG)
{
fuse_reply_err (req, EISDIR);
return;
}
if (doc && class == DOC_FILE_INO_CLASS)
{
g_autofree char *write_path = NULL;
int write_fd = -1;
path = xdp_doc_dup_path (doc);
if ((fi->flags & 3) != O_RDONLY)
{
if (access (path, W_OK) != 0)
{
fuse_reply_err (req, errno);
return;
}
write_path = create_tmp_for_doc (doc, O_RDWR, &write_fd);
if (write_path == NULL)
{
fuse_reply_err (req, errno);
return;
}
}
fd = open (path, O_RDONLY);
if (fd < 0)
{
int errsv = errno;
if (write_fd >= 0)
close (write_fd);
fuse_reply_err (req, errsv);
return;
}
fh = xdp_fh_new (ino, fi, fd, NULL);
fh->trunc_fd = write_fd;
fh->trunc_path = g_steal_pointer (&write_path);
fh->real_path = g_steal_pointer (&path);
if (fuse_reply_open (req, fi))
xdp_fh_free (fh);
}
else if (class == TMPFILE_INO_CLASS &&
(tmp = find_tmp_by_id (class_ino)))
{
fd = open (tmp->backing_path, get_open_flags (fi));
if (fd < 0)
{
fuse_reply_err (req, errno);
return;
}
fh = xdp_fh_new (ino, fi, fd, tmp);
if (fuse_reply_open (req, fi))
xdp_fh_free (fh);
}
else
fuse_reply_err (req, EIO);
}
static void
xdp_fuse_create (fuse_req_t req,
fuse_ino_t parent,
const char *name,
mode_t mode,
struct fuse_file_info *fi)
{
struct fuse_entry_param e = {0};
XdpInodeClass parent_class = get_class (parent);
struct stat stbuf;
XdpFh *fh;
g_autoptr(GVariant) doc = NULL;
g_autofree char *basename = NULL;
g_autofree char *path = NULL;
XdpTmp *tmpfile;
int fd, res;
g_debug ("xdp_fuse_create %lx/%s, flags %o", parent, name, fi->flags);
if ((res = xdp_stat (parent, &stbuf, &doc)) != 0)
{
fuse_reply_err (req, res);
return;
}
if ((stbuf.st_mode & S_IFMT) != S_IFDIR)
{
fuse_reply_err (req, ENOTDIR);
return;
}
if (parent_class != APP_DOC_DIR_INO_CLASS &&
parent_class != DOC_DIR_INO_CLASS)
{
fuse_reply_err (req, EACCES);
return;
}
basename = xdp_doc_dup_basename (doc);
if (strcmp (name, basename) == 0)
{
g_autofree char *write_path = NULL;
int write_fd = -1;
guint32 doc_id = xdb_doc_id_from_name (name);
write_path = create_tmp_for_doc (doc, O_RDWR, &write_fd);
if (write_path == NULL)
{
fuse_reply_err (req, errno);
return;
}
path = xdp_doc_dup_path (doc);
fd = open (path, O_CREAT|O_EXCL|O_RDONLY);
if (fd < 0)
{
int errsv = errno;
if (write_fd >= 0)
close (write_fd);
fuse_reply_err (req, errsv);
return;
}
e.ino = make_inode (DOC_FILE_INO_CLASS, doc_id);
fh = xdp_fh_new (e.ino, fi, fd, NULL);
fh->truncated = TRUE;
fh->trunc_fd = write_fd;
fh->trunc_path = g_steal_pointer (&write_path);
fh->real_path = g_steal_pointer (&path);
if (xdp_fstat (fh, &e.attr) != 0)
{
xdp_fh_free (fh);
fuse_reply_err (req, EIO);
return;
}
e.attr_timeout = get_attr_cache_time (e.attr.st_mode);
e.entry_timeout = get_entry_cache_time (e.attr.st_mode);
if (fuse_reply_create (req, &e, fi))
xdp_fh_free (fh);
}
else
{
tmpfile = find_tmp_by_name (parent, name);
if (tmpfile != NULL && fi->flags & O_EXCL)
{
fuse_reply_err (req, EEXIST);
return;
}
if (tmpfile)
{
fd = open (tmpfile->backing_path, get_open_flags (fi));
if (fd == -1)
{
fuse_reply_err (req, errno);
return;
}
}
else
{
tmpfile = tmpfile_new (parent, name, doc, get_open_flags (fi), &fd);
if (tmpfile == NULL)
{
fuse_reply_err (req, errno);
return;
}
}
e.ino = make_inode (TMPFILE_INO_CLASS, tmpfile->tmp_id);
if (xdp_stat (e.ino, &e.attr, NULL) != 0)
{
fuse_reply_err (req, EIO);
return;
}
e.attr_timeout = get_attr_cache_time (e.attr.st_mode);
e.entry_timeout = get_entry_cache_time (e.attr.st_mode);
fh = xdp_fh_new (e.ino, fi, fd, tmpfile);
if (fuse_reply_create (req, &e, fi))
xdp_fh_free (fh);
}
}
static void
xdp_fuse_read (fuse_req_t req,
fuse_ino_t ino,
size_t size,
off_t off,
struct fuse_file_info *fi)
{
XdpFh *fh = (gpointer)fi->fh;
struct fuse_bufvec bufv = FUSE_BUFVEC_INIT (size);
static char c = 'x';
int fd;
fd = xdp_fh_get_fd (fh);
if (fd == -1)
{
bufv.buf[0].flags = 0;
bufv.buf[0].mem = &c;
bufv.buf[0].size = 0;
fuse_reply_data (req, &bufv, FUSE_BUF_NO_SPLICE);
return;
}
bufv.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
bufv.buf[0].fd = fd;
bufv.buf[0].pos = off;
fuse_reply_data (req, &bufv, FUSE_BUF_SPLICE_MOVE);
}
static void
xdp_fuse_write (fuse_req_t req,
fuse_ino_t ino,
const char *buf,
size_t size,
off_t off,
struct fuse_file_info *fi)
{
XdpFh *fh = (gpointer)fi->fh;
gssize res;
int fd;
if (fh->readonly)
{
fuse_reply_err (req, EACCES);
return;
}
fd = xdp_fh_get_fd (fh);
if (fd == -1)
{
fuse_reply_err (req, EIO);
return;
}
res = pwrite (fd, buf, size, off);
if (res < 0)
fuse_reply_err (req, errno);
else
fuse_reply_write (req, res);
}
static void
xdp_fuse_write_buf (fuse_req_t req,
fuse_ino_t ino,
struct fuse_bufvec *bufv,
off_t off,
struct fuse_file_info *fi)
{
XdpFh *fh = (gpointer)fi->fh;
struct fuse_bufvec dst = FUSE_BUFVEC_INIT(fuse_buf_size(bufv));
gssize res;
int fd;
if (fh->readonly)
{
fuse_reply_err (req, EACCES);
return;
}
fd = xdp_fh_get_fd (fh);
if (fd == -1)
{
fuse_reply_err (req, EIO);
return;
}
dst.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
dst.buf[0].fd = fd;
dst.buf[0].pos = off;
res = fuse_buf_copy (&dst, bufv, FUSE_BUF_SPLICE_NONBLOCK);
if (res < 0)
fuse_reply_err (req, -res);
else
fuse_reply_write (req, res);
}
static void
xdp_fuse_release (fuse_req_t req,
fuse_ino_t ino,
struct fuse_file_info *fi)
{
XdpFh *fh = (gpointer)fi->fh;
xdp_fh_free (fh);
fuse_reply_err (req, 0);
}
static void
xdp_fuse_rename (fuse_req_t req,
fuse_ino_t parent,
const char *name,
fuse_ino_t newparent,
const char *newname)
{
XdpInodeClass parent_class = get_class (parent);
g_autoptr (GVariant) doc = NULL;
int res;
fuse_ino_t inode;
struct stat stbuf = {0};
g_autofree char *basename = NULL;
XdpTmp *other_tmp, *tmp;
GList *l;
g_debug ("xdp_fuse_rename %lx/%s -> %lx/%s", parent, name, newparent, newname);
res = xdp_lookup (parent, name, &inode, &stbuf, &doc, &tmp);
if (res != 0)
{
fuse_reply_err (req, res);
return;
}
/* Only allow renames in (app) doc dirs, and only inside the same dir */
if ((parent_class != DOC_DIR_INO_CLASS &&
parent_class != APP_DOC_DIR_INO_CLASS) ||
parent != newparent ||
doc == NULL ||
/* Also, don't allow renaming non-tmpfiles */
tmp == NULL)
{
fuse_reply_err (req, EACCES);
return;
}
basename = xdp_doc_dup_basename (doc);
if (strcmp (newname, basename) == 0)
{
g_autofree char *real_path = xdp_doc_dup_path (doc);
/* Rename tmpfile to regular file */
/* Stop writes to all outstanding fds to the temp file */
for (l = open_files; l != NULL; l = l->next)
{
XdpFh *fh = l->data;
if (fh->tmp_id == tmp->tmp_id && fh->fd >= 0)
fh->readonly = TRUE;
}
if (rename (tmp->backing_path, real_path) != 0)
{
fuse_reply_err (req, errno);
return;
}
/* Clear backing path so we don't unlink it when freeing tmp */
g_clear_pointer (&tmp->backing_path, g_free);
tmpfile_free (tmp);
fuse_reply_err (req, 0);
}
else
{
/* Rename tmpfile to other tmpfile name */
other_tmp = find_tmp_by_name (newparent, newname);
if (other_tmp)
tmpfile_free (other_tmp);
g_free (tmp->name);
tmp->name = g_strdup (newname);
fuse_reply_err (req, 0);
}
}
static int
fh_truncate (XdpFh *fh, off_t size, struct stat *newattr)
{
int fd;
if (fh->trunc_fd >= 0 && !fh->truncated)
{
if (size != 0)
return -EACCES;
fh->truncated = TRUE;
fd = fh->trunc_fd;
}
else
{
fd = xdp_fh_get_fd (fh);
if (fd == -1)
return -EIO;
if (ftruncate (fd, size) != 0)
return - errno;
}
if (newattr)
{
int res = xdp_fstat (fh, newattr);
if (res < 0)
return res;
}
return 0;
}
static void
xdp_fuse_setattr (fuse_req_t req,
fuse_ino_t ino,
struct stat *attr,
int to_set,
struct fuse_file_info *fi)
{
g_debug ("xdp_fuse_setattr %lx %x %p", ino, to_set, fi);
if (to_set == FUSE_SET_ATTR_SIZE && fi != NULL)
{
XdpFh *fh = (gpointer)fi->fh;
int res;
struct stat newattr = {0};
/* ftruncate */
res = fh_truncate (fh, attr->st_size, &newattr);
if (res < 0)
{
fuse_reply_err (req, res);
return;
}
fuse_reply_attr (req, &newattr, get_attr_cache_time (newattr.st_mode));
}
else if (to_set == FUSE_SET_ATTR_SIZE && fi == NULL)
{
gboolean found = FALSE;
int res = 0;
GList *l;
struct stat newattr = {0};
struct stat *newattrp = &newattr;
/* truncate, truncate any open files (but EACCES if not open) */
for (l = open_files; l != NULL; l = l->next)
{
XdpFh *fh = l->data;
if (fh->inode == ino)
{
found = TRUE;
res = fh_truncate (fh, attr->st_size, newattrp);
newattrp = NULL;
}
}
if (!found)
{
fuse_reply_err (req, EACCES);
return;
}
if (res < 0)
{
fuse_reply_err (req, -res);
return;
}
fuse_reply_attr (req, &newattr, get_attr_cache_time (newattr.st_mode));
}
else if (to_set == FUSE_SET_ATTR_MODE)
{
gboolean found = FALSE;
int res, err = -1;
GList *l;
struct stat newattr = {0};
for (l = open_files; l != NULL; l = l->next)
{
XdpFh *fh = l->data;
if (fh->inode == ino)
{
int fd = xdp_fh_get_fd (fh);
if (fd != -1)
{
res = fchmod (fd, get_user_perms (attr));
if (!found)
{
if (res != 0)
err = -errno;
else
err = xdp_fstat (fh, &newattr);
found = TRUE;
}
}
}
}
if (!found)
{
fuse_reply_err (req, EACCES);
return;
}
if (err < 0)
{
fuse_reply_err (req, -err);
return;
}
fuse_reply_attr (req, &newattr, get_attr_cache_time (newattr.st_mode));
}
else
fuse_reply_err (req, ENOSYS);
}
static void
xdp_fuse_fsyncdir (fuse_req_t req,
fuse_ino_t ino,
int datasync,
struct fuse_file_info *fi)
{
XdpInodeClass class = get_class (ino);
guint64 class_ino = get_class_ino (ino);
guint32 doc_id;
if (class == DOC_DIR_INO_CLASS ||
class == APP_DOC_DIR_INO_CLASS)
{
g_autoptr (GVariant) doc = NULL;
if (class == APP_DOC_DIR_INO_CLASS)
doc_id = get_doc_id_from_app_doc_ino (class_ino);
else
doc_id = class_ino;
doc = xdp_doc_db_lookup_doc (db, doc_id);
if (doc != NULL)
{
g_autofree char *dirname = xdp_doc_dup_dirname (doc);
int fd = open (dirname, O_DIRECTORY|O_RDONLY);
if (fd >= 0)
{
if (datasync)
fdatasync (fd);
else
fsync (fd);
close (fd);
}
}
}
fuse_reply_err (req, 0);
}
static void
xdp_fuse_fsync (fuse_req_t req,
fuse_ino_t ino,
int datasync,
struct fuse_file_info *fi)
{
XdpInodeClass class = get_class (ino);
if (class == DOC_FILE_INO_CLASS ||
class == TMPFILE_INO_CLASS)
{
XdpFh *fh = (gpointer)fi->fh;
if (fh->fd >= 0)
fsync (fh->fd);
if (fh->truncated && fh->trunc_fd >= 0)
fsync (fh->trunc_fd);
}
fuse_reply_err (req, 0);
}
static void
xdp_fuse_unlink (fuse_req_t req,
fuse_ino_t parent,
const char *name)
{
XdpInodeClass parent_class = get_class (parent);
g_autoptr (GVariant) doc = NULL;
int res;
fuse_ino_t inode;
struct stat stbuf = {0};
g_autofree char *basename = NULL;
XdpTmp *tmp;
g_debug ("xdp_fuse_unlink %lx/%s", parent, name);
res = xdp_lookup (parent, name, &inode, &stbuf, &doc, &tmp);
if (res != 0)
{
fuse_reply_err (req, res);
return;
}
/* Only allow unlink in (app) doc dirs */
if ((parent_class != DOC_DIR_INO_CLASS &&
parent_class != APP_DOC_DIR_INO_CLASS) ||
doc == NULL)
{
fuse_reply_err (req, EACCES);
return;
}
basename = xdp_doc_dup_basename (doc);
if (strcmp (name, basename) == 0)
{
g_autofree char *real_path = xdp_doc_dup_path (doc);
if (unlink (real_path) != 0)
{
fuse_reply_err (req, errno);
return;
}
fuse_reply_err (req, 0);
}
else
{
tmpfile_free (tmp);
fuse_reply_err (req, 0);
}
}
static struct fuse_lowlevel_ops xdp_fuse_oper = {
.lookup = xdp_fuse_lookup,
.getattr = xdp_fuse_getattr,
.opendir = xdp_fuse_opendir,
.readdir = xdp_fuse_readdir,
.releasedir = xdp_fuse_releasedir,
.fsyncdir = xdp_fuse_fsyncdir,
.open = xdp_fuse_open,
.create = xdp_fuse_create,
.read = xdp_fuse_read,
.write = xdp_fuse_write,
.write_buf = xdp_fuse_write_buf,
.release = xdp_fuse_release,
.rename = xdp_fuse_rename,
.setattr = xdp_fuse_setattr,
.fsync = xdp_fuse_fsync,
.unlink = xdp_fuse_unlink,
};
typedef struct
{
GSource source;
struct fuse_chan *ch;
gpointer fd_tag;
} FuseSource;
static gboolean
fuse_source_dispatch (GSource *source,
GSourceFunc func,
gpointer user_data)
{
FuseSource *fs = (FuseSource *)source;
struct fuse_chan *ch = fs->ch;
struct fuse_session *se = fuse_chan_session (ch);
gsize bufsize = fuse_chan_bufsize (ch);
if (g_source_query_unix_fd (source, fs->fd_tag) != 0)
{
int res = 0;
char *buf = (char *) g_malloc (bufsize);
while (TRUE)
{
struct fuse_chan *tmpch = ch;
struct fuse_buf fbuf = {
.mem = buf,
.size = bufsize,
};
res = fuse_session_receive_buf (se, &fbuf, &tmpch);
if (res == -EINTR)
continue;
if (res <= 0)
break;
fuse_session_process_buf (se, &fbuf, tmpch);
}
g_free (buf);
}
return TRUE;
}
static GSource *
fuse_source_new (struct fuse_chan *ch)
{
static GSourceFuncs source_funcs = {
NULL, NULL,
fuse_source_dispatch
/* should have a finalize, but it will never happen */
};
FuseSource *fs;
GSource *source;
GError *error = NULL;
int fd;
source = g_source_new (&source_funcs, sizeof (FuseSource));
fs = (FuseSource *) source;
fs->ch = ch;
g_source_set_name (source, "fuse source");
fd = fuse_chan_fd(ch);
g_unix_set_fd_nonblocking (fd, TRUE, &error);
g_assert_no_error (error);
fs->fd_tag = g_source_add_unix_fd (source, fd, G_IO_IN);
return source;
}
static struct fuse_session *session = NULL;
static struct fuse_chan *main_ch = NULL;
static char *mount_path = NULL;
void
xdp_fuse_exit (void)
{
if (session)
fuse_session_reset (session);
if (main_ch)
fuse_session_remove_chan (main_ch);
if (session)
fuse_session_destroy (session);
if (main_ch)
fuse_unmount (mount_path, main_ch);
}
gboolean
xdp_fuse_init (XdpDocDb *_db,
GError **error)
{
char *argv[] = { "xdp-fuse", "-osplice_write,splice_move,splice_read" };
struct fuse_args args = FUSE_ARGS_INIT(G_N_ELEMENTS(argv), argv);
struct fuse_chan *ch;
GSource *source;
db = _db;
app_name_to_id =
g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
app_id_to_name =
g_hash_table_new_full (g_direct_hash, g_direct_equal, NULL, NULL);
next_app_id = IN_HOMEDIR_APP_ID + 1;
next_tmp_id = 1;
mount_path = g_build_filename (g_get_user_runtime_dir(), "doc", NULL);
if (g_mkdir_with_parents (mount_path, 0700))
{
g_set_error (error, XDP_ERROR, XDP_ERROR_FAILED,
"Unable to create dir %s\n", mount_path);
return FALSE;
}
main_ch = ch = fuse_mount (mount_path, &args);
if (ch == NULL)
{
g_set_error (error, XDP_ERROR, XDP_ERROR_FAILED, "Can't mount fuse fs");
return FALSE;
}
session = fuse_lowlevel_new (&args, &xdp_fuse_oper,
sizeof (xdp_fuse_oper), NULL);
if (session == NULL)
{
g_set_error (error, XDP_ERROR, XDP_ERROR_FAILED,
"Can't create fuse session");
return FALSE;
}
fuse_session_add_chan (session, ch);
source = fuse_source_new (ch);
g_source_attach (source, NULL);
return TRUE;
}