1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288
|
/*
* VFS module to alter the algorithm to calculate
* the struct file_id used as key for the share mode
* and byte range locking db's.
*
* Copyright (C) 2007, Stefan Metzmacher
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
static int vfs_fileid_debug_level = DBGC_VFS;
#undef DBGC_CLASS
#define DBGC_CLASS vfs_fileid_debug_level
struct fileid_mount_entry {
SMB_DEV_T device;
const char *mnt_fsname;
fsid_t fsid;
uint64_t devid;
};
struct fileid_handle_data {
uint64_t (*device_mapping_fn)(struct fileid_handle_data *data,
SMB_DEV_T dev);
unsigned num_mount_entries;
struct fileid_mount_entry *mount_entries;
};
/* load all the mount entries from the mtab */
static void fileid_load_mount_entries(struct fileid_handle_data *data)
{
FILE *f;
struct mntent *m;
data->num_mount_entries = 0;
TALLOC_FREE(data->mount_entries);
f = setmntent("/etc/mtab", "r");
if (!f) return;
while ((m = getmntent(f))) {
struct stat st;
struct statfs sfs;
struct fileid_mount_entry *cur;
if (stat(m->mnt_dir, &st) != 0) continue;
if (statfs(m->mnt_dir, &sfs) != 0) continue;
if (strncmp(m->mnt_fsname, "/dev/", 5) == 0) {
m->mnt_fsname += 5;
}
data->mount_entries = TALLOC_REALLOC_ARRAY(data,
data->mount_entries,
struct fileid_mount_entry,
data->num_mount_entries+1);
if (data->mount_entries == NULL) {
goto nomem;
}
cur = &data->mount_entries[data->num_mount_entries];
cur->device = st.st_dev;
cur->mnt_fsname = talloc_strdup(data->mount_entries,
m->mnt_fsname);
if (!cur->mnt_fsname) goto nomem;
cur->fsid = sfs.f_fsid;
cur->devid = (uint64_t)-1;
data->num_mount_entries++;
}
endmntent(f);
return;
nomem:
if (f) endmntent(f);
data->num_mount_entries = 0;
TALLOC_FREE(data->mount_entries);
return;
}
/* find a mount entry given a dev_t */
static struct fileid_mount_entry *fileid_find_mount_entry(struct fileid_handle_data *data,
SMB_DEV_T dev)
{
int i;
if (data->num_mount_entries == 0) {
fileid_load_mount_entries(data);
}
for (i=0;i<data->num_mount_entries;i++) {
if (data->mount_entries[i].device == dev) {
return &data->mount_entries[i];
}
}
/* 2nd pass after reloading */
fileid_load_mount_entries(data);
for (i=0;i<data->num_mount_entries;i++) {
if (data->mount_entries[i].device == dev) {
return &data->mount_entries[i];
}
}
return NULL;
}
/* a 64 bit hash, based on the one in tdb */
static uint64_t fileid_uint64_hash(const uint8_t *s, size_t len)
{
uint64_t value; /* Used to compute the hash value. */
uint32_t i; /* Used to cycle through random values. */
/* Set the initial value from the key size. */
for (value = 0x238F13AFLL * len, i=0; i < len; i++)
value = (value + (s[i] << (i*5 % 24)));
return (1103515243LL * value + 12345LL);
}
/* a device mapping using a fsname */
static uint64_t fileid_device_mapping_fsname(struct fileid_handle_data *data,
SMB_DEV_T dev)
{
struct fileid_mount_entry *m;
m = fileid_find_mount_entry(data, dev);
if (!m) return dev;
if (m->devid == (uint64_t)-1) {
m->devid = fileid_uint64_hash((uint8_t *)m->mnt_fsname,
strlen(m->mnt_fsname));
}
return m->devid;
}
/* device mapping functions using a fsid */
static uint64_t fileid_device_mapping_fsid(struct fileid_handle_data *data,
SMB_DEV_T dev)
{
struct fileid_mount_entry *m;
m = fileid_find_mount_entry(data, dev);
if (!m) return dev;
if (m->devid == (uint64_t)-1) {
if (sizeof(fsid_t) > sizeof(uint64_t)) {
m->devid = fileid_uint64_hash((uint8_t *)&m->fsid,
sizeof(m->fsid));
} else {
union {
uint64_t ret;
fsid_t fsid;
} u;
ZERO_STRUCT(u);
u.fsid = m->fsid;
m->devid = u.ret;
}
}
return m->devid;
}
static int fileid_connect(struct vfs_handle_struct *handle,
const char *service, const char *user)
{
struct fileid_handle_data *data;
const char *algorithm;
data = talloc_zero(handle->conn->mem_ctx, struct fileid_handle_data);
if (!data) {
DEBUG(0, ("talloc_zero() failed\n"));
return -1;
}
data->device_mapping_fn = fileid_device_mapping_fsid;
algorithm = lp_parm_const_string(SNUM(handle->conn),
"fileid", "algorithm",
"fsname");
if (strcmp("fsname", algorithm) == 0) {
data->device_mapping_fn = fileid_device_mapping_fsname;
} else if (strcmp("fsid", algorithm) == 0) {
data->device_mapping_fn = fileid_device_mapping_fsid;
} else {
DEBUG(0,("fileid_connect(): unknown algorithm[%s]\n", algorithm));
return -1;
}
SMB_VFS_HANDLE_SET_DATA(handle, data, NULL,
struct fileid_handle_data,
return -1);
DEBUG(10, ("fileid_connect(): connect to service[%s] with algorithm[%s]\n",
service, algorithm));
return SMB_VFS_NEXT_CONNECT(handle, service, user);
}
static void fileid_disconnect(struct vfs_handle_struct *handle)
{
DEBUG(10,("fileid_disconnect() connect to service[%s].\n",
lp_servicename(SNUM(handle->conn))));
SMB_VFS_NEXT_DISCONNECT(handle);
}
static struct file_id fileid_file_id_create(struct vfs_handle_struct *handle,
SMB_DEV_T dev, SMB_INO_T inode)
{
struct fileid_handle_data *data;
struct file_id id;
ZERO_STRUCT(id);
SMB_VFS_HANDLE_GET_DATA(handle, data,
struct fileid_handle_data,
return id);
id.devid = data->device_mapping_fn(data, dev);
id.inode = inode;
return id;
}
static vfs_op_tuple fileid_ops[] = {
/* Disk operations */
{
SMB_VFS_OP(fileid_connect),
SMB_VFS_OP_CONNECT,
SMB_VFS_LAYER_TRANSPARENT
},
{
SMB_VFS_OP(fileid_disconnect),
SMB_VFS_OP_DISCONNECT,
SMB_VFS_LAYER_TRANSPARENT
},
/* File operations */
{
SMB_VFS_OP(fileid_file_id_create),
SMB_VFS_OP_FILE_ID_CREATE,
SMB_VFS_LAYER_OPAQUE
},
/* End marker */
{
SMB_VFS_OP(NULL),
SMB_VFS_OP_NOOP,
SMB_VFS_LAYER_NOOP
}
};
NTSTATUS vfs_fileid_init(void);
NTSTATUS vfs_fileid_init(void)
{
NTSTATUS ret;
ret = smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "fileid", fileid_ops);
if (!NT_STATUS_IS_OK(ret)) {
return ret;
}
vfs_fileid_debug_level = debug_add_class("fileid");
if (vfs_fileid_debug_level == -1) {
vfs_fileid_debug_level = DBGC_VFS;
DEBUG(0, ("vfs_fileid: Couldn't register custom debugging class!\n"));
} else {
DEBUG(10, ("vfs_fileid: Debug class number of 'fileid': %d\n", vfs_fileid_debug_level));
}
return ret;
}
|