Adel Gadllah | 0b07de8 | 2008-06-26 13:48:27 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2004 Peter M. Jones <pjones@redhat.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public Licens |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | #include <linux/list.h> |
| 21 | #include <linux/genhd.h> |
| 22 | #include <linux/spinlock.h> |
| 23 | #include <linux/parser.h> |
| 24 | #include <linux/capability.h> |
| 25 | #include <linux/bitops.h> |
| 26 | |
| 27 | #include <scsi/scsi.h> |
| 28 | #include <linux/cdrom.h> |
| 29 | |
| 30 | int blk_cmd_filter_verify_command(struct blk_scsi_cmd_filter *filter, |
| 31 | unsigned char *cmd, mode_t *f_mode) |
| 32 | { |
| 33 | /* root can do any command. */ |
| 34 | if (capable(CAP_SYS_RAWIO)) |
| 35 | return 0; |
| 36 | |
| 37 | /* if there's no filter set, assume we're filtering everything out */ |
| 38 | if (!filter) |
| 39 | return -EPERM; |
| 40 | |
| 41 | /* Anybody who can open the device can do a read-safe command */ |
| 42 | if (test_bit(cmd[0], filter->read_ok)) |
| 43 | return 0; |
| 44 | |
| 45 | /* Write-safe commands require a writable open */ |
| 46 | if (test_bit(cmd[0], filter->write_ok) && (*f_mode & FMODE_WRITE)) |
| 47 | return 0; |
| 48 | |
| 49 | return -EPERM; |
| 50 | } |
| 51 | EXPORT_SYMBOL(blk_cmd_filter_verify_command); |
| 52 | |
| 53 | int blk_verify_command(struct file *file, unsigned char *cmd) |
| 54 | { |
| 55 | struct gendisk *disk; |
| 56 | struct inode *inode; |
| 57 | |
| 58 | if (!file) |
| 59 | return -EINVAL; |
| 60 | |
| 61 | inode = file->f_dentry->d_inode; |
| 62 | if (!inode) |
| 63 | return -EINVAL; |
| 64 | |
| 65 | disk = inode->i_bdev->bd_disk; |
| 66 | |
| 67 | return blk_cmd_filter_verify_command(&disk->cmd_filter, |
| 68 | cmd, &file->f_mode); |
| 69 | } |
| 70 | EXPORT_SYMBOL(blk_verify_command); |
| 71 | |
| 72 | /* and now, the sysfs stuff */ |
| 73 | static ssize_t rcf_cmds_show(struct blk_scsi_cmd_filter *filter, char *page, |
| 74 | int rw) |
| 75 | { |
| 76 | char *npage = page; |
| 77 | unsigned long *okbits; |
| 78 | int i; |
| 79 | |
| 80 | if (rw == READ) |
| 81 | okbits = filter->read_ok; |
| 82 | else |
| 83 | okbits = filter->write_ok; |
| 84 | |
| 85 | for (i = 0; i < BLK_SCSI_MAX_CMDS; i++) { |
| 86 | if (test_bit(i, okbits)) { |
| 87 | sprintf(npage, "%02x", i); |
| 88 | npage += 2; |
| 89 | if (i < BLK_SCSI_MAX_CMDS - 1) |
| 90 | sprintf(npage++, " "); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | if (npage != page) |
| 95 | npage += sprintf(npage, "\n"); |
| 96 | |
| 97 | return npage - page; |
| 98 | } |
| 99 | |
| 100 | static ssize_t rcf_readcmds_show(struct blk_scsi_cmd_filter *filter, char *page) |
| 101 | { |
| 102 | return rcf_cmds_show(filter, page, READ); |
| 103 | } |
| 104 | |
| 105 | static ssize_t rcf_writecmds_show(struct blk_scsi_cmd_filter *filter, |
| 106 | char *page) |
| 107 | { |
| 108 | return rcf_cmds_show(filter, page, WRITE); |
| 109 | } |
| 110 | |
| 111 | static ssize_t rcf_cmds_store(struct blk_scsi_cmd_filter *filter, |
| 112 | const char *page, size_t count, int rw) |
| 113 | { |
| 114 | ssize_t ret = 0; |
| 115 | unsigned long okbits[BLK_SCSI_CMD_PER_LONG], *target_okbits; |
| 116 | int cmd, status, len; |
| 117 | substring_t ss; |
| 118 | |
| 119 | memset(&okbits, 0, sizeof(okbits)); |
| 120 | |
| 121 | for (len = strlen(page); len > 0; len -= 3) { |
| 122 | if (len < 2) |
| 123 | break; |
| 124 | ss.from = (char *) page + ret; |
| 125 | ss.to = (char *) page + ret + 2; |
| 126 | ret += 3; |
| 127 | status = match_hex(&ss, &cmd); |
| 128 | /* either of these cases means invalid input, so do nothing. */ |
| 129 | if (status || cmd >= BLK_SCSI_MAX_CMDS) |
| 130 | return -EINVAL; |
| 131 | |
| 132 | __set_bit(cmd, okbits); |
| 133 | } |
| 134 | |
| 135 | if (rw == READ) |
| 136 | target_okbits = filter->read_ok; |
| 137 | else |
| 138 | target_okbits = filter->write_ok; |
| 139 | |
| 140 | memmove(target_okbits, okbits, sizeof(okbits)); |
| 141 | return count; |
| 142 | } |
| 143 | |
| 144 | static ssize_t rcf_readcmds_store(struct blk_scsi_cmd_filter *filter, |
| 145 | const char *page, size_t count) |
| 146 | { |
| 147 | return rcf_cmds_store(filter, page, count, READ); |
| 148 | } |
| 149 | |
| 150 | static ssize_t rcf_writecmds_store(struct blk_scsi_cmd_filter *filter, |
| 151 | const char *page, size_t count) |
| 152 | { |
| 153 | return rcf_cmds_store(filter, page, count, WRITE); |
| 154 | } |
| 155 | |
| 156 | struct rcf_sysfs_entry { |
| 157 | struct attribute attr; |
| 158 | ssize_t (*show)(struct blk_scsi_cmd_filter *, char *); |
| 159 | ssize_t (*store)(struct blk_scsi_cmd_filter *, const char *, size_t); |
| 160 | }; |
| 161 | |
| 162 | static struct rcf_sysfs_entry rcf_readcmds_entry = { |
| 163 | .attr = { .name = "read_table", .mode = S_IRUGO | S_IWUSR }, |
| 164 | .show = rcf_readcmds_show, |
| 165 | .store = rcf_readcmds_store, |
| 166 | }; |
| 167 | |
| 168 | static struct rcf_sysfs_entry rcf_writecmds_entry = { |
| 169 | .attr = {.name = "write_table", .mode = S_IRUGO | S_IWUSR }, |
| 170 | .show = rcf_writecmds_show, |
| 171 | .store = rcf_writecmds_store, |
| 172 | }; |
| 173 | |
| 174 | static struct attribute *default_attrs[] = { |
| 175 | &rcf_readcmds_entry.attr, |
| 176 | &rcf_writecmds_entry.attr, |
| 177 | NULL, |
| 178 | }; |
| 179 | |
| 180 | #define to_rcf(atr) container_of((atr), struct rcf_sysfs_entry, attr) |
| 181 | |
| 182 | static ssize_t |
| 183 | rcf_attr_show(struct kobject *kobj, struct attribute *attr, char *page) |
| 184 | { |
| 185 | struct rcf_sysfs_entry *entry = to_rcf(attr); |
| 186 | struct blk_scsi_cmd_filter *filter; |
| 187 | |
| 188 | filter = container_of(kobj, struct blk_scsi_cmd_filter, kobj); |
| 189 | if (entry->show) |
| 190 | return entry->show(filter, page); |
| 191 | |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static ssize_t |
| 196 | rcf_attr_store(struct kobject *kobj, struct attribute *attr, |
| 197 | const char *page, size_t length) |
| 198 | { |
| 199 | struct rcf_sysfs_entry *entry = to_rcf(attr); |
| 200 | struct blk_scsi_cmd_filter *filter; |
| 201 | |
| 202 | if (!capable(CAP_SYS_RAWIO)) |
| 203 | return -EPERM; |
| 204 | |
| 205 | if (!entry->store) |
| 206 | return -EINVAL; |
| 207 | |
| 208 | filter = container_of(kobj, struct blk_scsi_cmd_filter, kobj); |
| 209 | return entry->store(filter, page, length); |
| 210 | } |
| 211 | |
| 212 | static struct sysfs_ops rcf_sysfs_ops = { |
| 213 | .show = rcf_attr_show, |
| 214 | .store = rcf_attr_store, |
| 215 | }; |
| 216 | |
| 217 | static struct kobj_type rcf_ktype = { |
| 218 | .sysfs_ops = &rcf_sysfs_ops, |
| 219 | .default_attrs = default_attrs, |
| 220 | }; |
| 221 | |
Adel Gadllah | 06a452e | 2008-06-27 09:16:17 +0200 | [diff] [blame] | 222 | #ifndef MAINTENANCE_IN_CMD |
| 223 | #define MAINTENANCE_IN_CMD 0xa3 |
| 224 | #endif |
| 225 | |
Adel Gadllah | 0b07de8 | 2008-06-26 13:48:27 +0200 | [diff] [blame] | 226 | static void rcf_set_defaults(struct blk_scsi_cmd_filter *filter) |
| 227 | { |
| 228 | /* Basic read-only commands */ |
| 229 | __set_bit(TEST_UNIT_READY, filter->read_ok); |
| 230 | __set_bit(REQUEST_SENSE, filter->read_ok); |
| 231 | __set_bit(READ_6, filter->read_ok); |
| 232 | __set_bit(READ_10, filter->read_ok); |
| 233 | __set_bit(READ_12, filter->read_ok); |
| 234 | __set_bit(READ_16, filter->read_ok); |
| 235 | __set_bit(READ_BUFFER, filter->read_ok); |
| 236 | __set_bit(READ_DEFECT_DATA, filter->read_ok); |
Adel Gadllah | 06a452e | 2008-06-27 09:16:17 +0200 | [diff] [blame] | 237 | __set_bit(READ_CAPACITY, filter->read_ok); |
Adel Gadllah | 0b07de8 | 2008-06-26 13:48:27 +0200 | [diff] [blame] | 238 | __set_bit(READ_LONG, filter->read_ok); |
| 239 | __set_bit(INQUIRY, filter->read_ok); |
| 240 | __set_bit(MODE_SENSE, filter->read_ok); |
| 241 | __set_bit(MODE_SENSE_10, filter->read_ok); |
| 242 | __set_bit(LOG_SENSE, filter->read_ok); |
| 243 | __set_bit(START_STOP, filter->read_ok); |
| 244 | __set_bit(GPCMD_VERIFY_10, filter->read_ok); |
| 245 | __set_bit(VERIFY_16, filter->read_ok); |
Adel Gadllah | 06a452e | 2008-06-27 09:16:17 +0200 | [diff] [blame] | 246 | __set_bit(REPORT_LUNS, filter->read_ok); |
| 247 | __set_bit(SERVICE_ACTION_IN, filter->read_ok); |
| 248 | __set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok); |
| 249 | __set_bit(MAINTENANCE_IN_CMD, filter->read_ok); |
Adel Gadllah | 0b07de8 | 2008-06-26 13:48:27 +0200 | [diff] [blame] | 250 | __set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok); |
| 251 | |
| 252 | /* Audio CD commands */ |
| 253 | __set_bit(GPCMD_PLAY_CD, filter->read_ok); |
| 254 | __set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok); |
| 255 | __set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok); |
| 256 | __set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok); |
| 257 | __set_bit(GPCMD_PAUSE_RESUME, filter->read_ok); |
| 258 | |
| 259 | /* CD/DVD data reading */ |
| 260 | __set_bit(GPCMD_READ_CD, filter->read_ok); |
| 261 | __set_bit(GPCMD_READ_CD_MSF, filter->read_ok); |
| 262 | __set_bit(GPCMD_READ_DISC_INFO, filter->read_ok); |
| 263 | __set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok); |
| 264 | __set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok); |
| 265 | __set_bit(GPCMD_READ_HEADER, filter->read_ok); |
| 266 | __set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok); |
| 267 | __set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok); |
| 268 | __set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok); |
| 269 | __set_bit(GPCMD_REPORT_KEY, filter->read_ok); |
| 270 | __set_bit(GPCMD_SCAN, filter->read_ok); |
| 271 | __set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok); |
| 272 | __set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok); |
| 273 | __set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok); |
| 274 | __set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok); |
| 275 | __set_bit(GPCMD_SEEK, filter->read_ok); |
| 276 | __set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok); |
| 277 | |
| 278 | /* Basic writing commands */ |
| 279 | __set_bit(WRITE_6, filter->write_ok); |
| 280 | __set_bit(WRITE_10, filter->write_ok); |
| 281 | __set_bit(WRITE_VERIFY, filter->write_ok); |
| 282 | __set_bit(WRITE_12, filter->write_ok); |
| 283 | __set_bit(WRITE_VERIFY_12, filter->write_ok); |
| 284 | __set_bit(WRITE_16, filter->write_ok); |
| 285 | __set_bit(WRITE_LONG, filter->write_ok); |
| 286 | __set_bit(WRITE_LONG_2, filter->write_ok); |
| 287 | __set_bit(ERASE, filter->write_ok); |
| 288 | __set_bit(GPCMD_MODE_SELECT_10, filter->write_ok); |
| 289 | __set_bit(MODE_SELECT, filter->write_ok); |
| 290 | __set_bit(LOG_SELECT, filter->write_ok); |
| 291 | __set_bit(GPCMD_BLANK, filter->write_ok); |
| 292 | __set_bit(GPCMD_CLOSE_TRACK, filter->write_ok); |
| 293 | __set_bit(GPCMD_FLUSH_CACHE, filter->write_ok); |
| 294 | __set_bit(GPCMD_FORMAT_UNIT, filter->write_ok); |
| 295 | __set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok); |
| 296 | __set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok); |
| 297 | __set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok); |
| 298 | __set_bit(GPCMD_SEND_EVENT, filter->write_ok); |
| 299 | __set_bit(GPCMD_SEND_KEY, filter->write_ok); |
| 300 | __set_bit(GPCMD_SEND_OPC, filter->write_ok); |
| 301 | __set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok); |
| 302 | __set_bit(GPCMD_SET_SPEED, filter->write_ok); |
| 303 | __set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok); |
| 304 | __set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok); |
| 305 | __set_bit(GPCMD_SET_STREAMING, filter->write_ok); |
| 306 | } |
| 307 | |
| 308 | int blk_register_filter(struct gendisk *disk) |
| 309 | { |
| 310 | int ret; |
| 311 | struct blk_scsi_cmd_filter *filter = &disk->cmd_filter; |
| 312 | struct kobject *parent = kobject_get(disk->holder_dir->parent); |
| 313 | |
| 314 | if (!parent) |
| 315 | return -ENODEV; |
| 316 | |
| 317 | ret = kobject_init_and_add(&filter->kobj, &rcf_ktype, parent, |
| 318 | "%s", "cmd_filter"); |
| 319 | |
| 320 | if (ret < 0) |
| 321 | return ret; |
| 322 | |
| 323 | rcf_set_defaults(filter); |
| 324 | return 0; |
| 325 | } |
| 326 | |
| 327 | void blk_unregister_filter(struct gendisk *disk) |
| 328 | { |
| 329 | struct blk_scsi_cmd_filter *filter = &disk->cmd_filter; |
| 330 | |
| 331 | kobject_put(&filter->kobj); |
| 332 | kobject_put(disk->holder_dir->parent); |
| 333 | } |
| 334 | |