1 /* 2 * Changes: 3 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000 4 * - get rid of some verify_areas and use __copy*user and __get/put_user 5 * for the ones that remain 6 */ 7 #include <linux/module.h> 8 #include <linux/blkdev.h> 9 #include <linux/interrupt.h> 10 #include <linux/errno.h> 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/mm.h> 14 #include <linux/string.h> 15 #include <asm/uaccess.h> 16 17 #include <scsi/scsi.h> 18 #include <scsi/scsi_device.h> 19 #include <scsi/scsi_eh.h> 20 #include <scsi/scsi_host.h> 21 #include <scsi/scsi_ioctl.h> 22 #include <scsi/scsi_request.h> 23 #include <scsi/sg.h> 24 #include <scsi/scsi_dbg.h> 25 26 #include "scsi_logging.h" 27 28 #define NORMAL_RETRIES 5 29 #define IOCTL_NORMAL_TIMEOUT (10 * HZ) 30 31 #define MAX_BUF PAGE_SIZE 32 33 /** 34 * ioctl_probe -- return host identification 35 * @host: host to identify 36 * @buffer: userspace buffer for identification 37 * 38 * Return an identifying string at @buffer, if @buffer is non-NULL, filling 39 * to the length stored at * (int *) @buffer. 40 */ 41 static int ioctl_probe(struct Scsi_Host *host, void __user *buffer) 42 { 43 unsigned int len, slen; 44 const char *string; 45 46 if (buffer) { 47 if (get_user(len, (unsigned int __user *) buffer)) 48 return -EFAULT; 49 50 if (host->hostt->info) 51 string = host->hostt->info(host); 52 else 53 string = host->hostt->name; 54 if (string) { 55 slen = strlen(string); 56 if (len > slen) 57 len = slen + 1; 58 if (copy_to_user(buffer, string, len)) 59 return -EFAULT; 60 } 61 } 62 return 1; 63 } 64 65 /* 66 67 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host. 68 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used. 69 * 70 * dev is the SCSI device struct ptr, *(int *) arg is the length of the 71 * input data, if any, not including the command string & counts, 72 * *((int *)arg + 1) is the output buffer size in bytes. 73 * 74 * *(char *) ((int *) arg)[2] the actual command byte. 75 * 76 * Note that if more than MAX_BUF bytes are requested to be transferred, 77 * the ioctl will fail with error EINVAL. 78 * 79 * This size *does not* include the initial lengths that were passed. 80 * 81 * The SCSI command is read from the memory location immediately after the 82 * length words, and the input data is right after the command. The SCSI 83 * routines know the command size based on the opcode decode. 84 * 85 * The output area is then filled in starting from the command byte. 86 */ 87 88 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd, 89 int timeout, int retries) 90 { 91 int result; 92 struct scsi_sense_hdr sshdr; 93 94 SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd)); 95 96 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, 97 &sshdr, timeout, retries); 98 99 SCSI_LOG_IOCTL(2, printk("Ioctl returned 0x%x\n", result)); 100 101 if ((driver_byte(result) & DRIVER_SENSE) && 102 (scsi_sense_valid(&sshdr))) { 103 switch (sshdr.sense_key) { 104 case ILLEGAL_REQUEST: 105 if (cmd[0] == ALLOW_MEDIUM_REMOVAL) 106 sdev->lockable = 0; 107 else 108 printk(KERN_INFO "ioctl_internal_command: " 109 "ILLEGAL REQUEST asc=0x%x ascq=0x%x\n", 110 sshdr.asc, sshdr.ascq); 111 break; 112 case NOT_READY: /* This happens if there is no disc in drive */ 113 if (sdev->removable && (cmd[0] != TEST_UNIT_READY)) { 114 printk(KERN_INFO "Device not ready. Make sure" 115 " there is a disc in the drive.\n"); 116 break; 117 } 118 case UNIT_ATTENTION: 119 if (sdev->removable) { 120 sdev->changed = 1; 121 result = 0; /* This is no longer considered an error */ 122 break; 123 } 124 default: /* Fall through for non-removable media */ 125 sdev_printk(KERN_INFO, sdev, 126 "ioctl_internal_command return code = %x\n", 127 result); 128 scsi_print_sense_hdr(" ", &sshdr); 129 break; 130 } 131 } 132 133 SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n")); 134 return result; 135 } 136 137 int scsi_set_medium_removal(struct scsi_device *sdev, char state) 138 { 139 char scsi_cmd[MAX_COMMAND_SIZE]; 140 int ret; 141 142 if (!sdev->removable || !sdev->lockable) 143 return 0; 144 145 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL; 146 scsi_cmd[1] = 0; 147 scsi_cmd[2] = 0; 148 scsi_cmd[3] = 0; 149 scsi_cmd[4] = state; 150 scsi_cmd[5] = 0; 151 152 ret = ioctl_internal_command(sdev, scsi_cmd, 153 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES); 154 if (ret == 0) 155 sdev->locked = (state == SCSI_REMOVAL_PREVENT); 156 return ret; 157 } 158 EXPORT_SYMBOL(scsi_set_medium_removal); 159 160 /* 161 * This interface is deprecated - users should use the scsi generic (sg) 162 * interface instead, as this is a more flexible approach to performing 163 * generic SCSI commands on a device. 164 * 165 * The structure that we are passed should look like: 166 * 167 * struct sdata { 168 * unsigned int inlen; [i] Length of data to be written to device 169 * unsigned int outlen; [i] Length of data to be read from device 170 * unsigned char cmd[x]; [i] SCSI command (6 <= x <= 12). 171 * [o] Data read from device starts here. 172 * [o] On error, sense buffer starts here. 173 * unsigned char wdata[y]; [i] Data written to device starts here. 174 * }; 175 * Notes: 176 * - The SCSI command length is determined by examining the 1st byte 177 * of the given command. There is no way to override this. 178 * - Data transfers are limited to PAGE_SIZE (4K on i386, 8K on alpha). 179 * - The length (x + y) must be at least OMAX_SB_LEN bytes long to 180 * accommodate the sense buffer when an error occurs. 181 * The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that 182 * old code will not be surprised. 183 * - If a Unix error occurs (e.g. ENOMEM) then the user will receive 184 * a negative return and the Unix error code in 'errno'. 185 * If the SCSI command succeeds then 0 is returned. 186 * Positive numbers returned are the compacted SCSI error codes (4 187 * bytes in one int) where the lowest byte is the SCSI status. 188 * See the drivers/scsi/scsi.h file for more information on this. 189 * 190 */ 191 #define OMAX_SB_LEN 16 /* Old sense buffer length */ 192 193 int scsi_ioctl_send_command(struct scsi_device *sdev, 194 struct scsi_ioctl_command __user *sic) 195 { 196 char *buf; 197 unsigned char cmd[MAX_COMMAND_SIZE]; 198 unsigned char sense[SCSI_SENSE_BUFFERSIZE]; 199 char __user *cmd_in; 200 unsigned char opcode; 201 unsigned int inlen, outlen, cmdlen; 202 unsigned int needed, buf_needed; 203 int timeout, retries, result; 204 int data_direction; 205 gfp_t gfp_mask = GFP_KERNEL; 206 207 if (!sic) 208 return -EINVAL; 209 210 if (sdev->host->unchecked_isa_dma) 211 gfp_mask |= GFP_DMA; 212 213 /* 214 * Verify that we can read at least this much. 215 */ 216 if (!access_ok(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command))) 217 return -EFAULT; 218 219 if(__get_user(inlen, &sic->inlen)) 220 return -EFAULT; 221 222 if(__get_user(outlen, &sic->outlen)) 223 return -EFAULT; 224 225 /* 226 * We do not transfer more than MAX_BUF with this interface. 227 * If the user needs to transfer more data than this, they 228 * should use scsi_generics (sg) instead. 229 */ 230 if (inlen > MAX_BUF) 231 return -EINVAL; 232 if (outlen > MAX_BUF) 233 return -EINVAL; 234 235 cmd_in = sic->data; 236 if(get_user(opcode, cmd_in)) 237 return -EFAULT; 238 239 needed = buf_needed = (inlen > outlen ? inlen : outlen); 240 if (buf_needed) { 241 buf_needed = (buf_needed + 511) & ~511; 242 if (buf_needed > MAX_BUF) 243 buf_needed = MAX_BUF; 244 buf = kmalloc(buf_needed, gfp_mask); 245 if (!buf) 246 return -ENOMEM; 247 memset(buf, 0, buf_needed); 248 if (inlen == 0) { 249 data_direction = DMA_FROM_DEVICE; 250 } else if (outlen == 0 ) { 251 data_direction = DMA_TO_DEVICE; 252 } else { 253 /* 254 * Can this ever happen? 255 */ 256 data_direction = DMA_BIDIRECTIONAL; 257 } 258 259 } else { 260 buf = NULL; 261 data_direction = DMA_NONE; 262 } 263 264 /* 265 * Obtain the command from the user's address space. 266 */ 267 cmdlen = COMMAND_SIZE(opcode); 268 269 result = -EFAULT; 270 271 if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen)) 272 goto error; 273 274 if(__copy_from_user(cmd, cmd_in, cmdlen)) 275 goto error; 276 277 /* 278 * Obtain the data to be sent to the device (if any). 279 */ 280 281 if(inlen && copy_from_user(buf, cmd_in + cmdlen, inlen)) 282 goto error; 283 284 switch (opcode) { 285 case SEND_DIAGNOSTIC: 286 case FORMAT_UNIT: 287 timeout = FORMAT_UNIT_TIMEOUT; 288 retries = 1; 289 break; 290 case START_STOP: 291 timeout = START_STOP_TIMEOUT; 292 retries = NORMAL_RETRIES; 293 break; 294 case MOVE_MEDIUM: 295 timeout = MOVE_MEDIUM_TIMEOUT; 296 retries = NORMAL_RETRIES; 297 break; 298 case READ_ELEMENT_STATUS: 299 timeout = READ_ELEMENT_STATUS_TIMEOUT; 300 retries = NORMAL_RETRIES; 301 break; 302 case READ_DEFECT_DATA: 303 timeout = READ_DEFECT_DATA_TIMEOUT; 304 retries = 1; 305 break; 306 default: 307 timeout = IOCTL_NORMAL_TIMEOUT; 308 retries = NORMAL_RETRIES; 309 break; 310 } 311 312 result = scsi_execute(sdev, cmd, data_direction, buf, needed, 313 sense, timeout, retries, 0); 314 315 /* 316 * If there was an error condition, pass the info back to the user. 317 */ 318 if (result) { 319 int sb_len = sizeof(*sense); 320 321 sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len; 322 if (copy_to_user(cmd_in, sense, sb_len)) 323 result = -EFAULT; 324 } else { 325 if (outlen && copy_to_user(cmd_in, buf, outlen)) 326 result = -EFAULT; 327 } 328 329 error: 330 kfree(buf); 331 return result; 332 } 333 EXPORT_SYMBOL(scsi_ioctl_send_command); 334 335 /* 336 * The scsi_ioctl_get_pci() function places into arg the value 337 * pci_dev::slot_name (8 characters) for the PCI device (if any). 338 * Returns: 0 on success 339 * -ENXIO if there isn't a PCI device pointer 340 * (could be because the SCSI driver hasn't been 341 * updated yet, or because it isn't a SCSI 342 * device) 343 * any copy_to_user() error on failure there 344 */ 345 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg) 346 { 347 struct device *dev = scsi_get_device(sdev->host); 348 349 if (!dev) 350 return -ENXIO; 351 return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0; 352 } 353 354 355 /* 356 * the scsi_ioctl() function differs from most ioctls in that it does 357 * not take a major/minor number as the dev field. Rather, it takes 358 * a pointer to a scsi_devices[] element, a structure. 359 */ 360 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 361 { 362 char scsi_cmd[MAX_COMMAND_SIZE]; 363 364 /* No idea how this happens.... */ 365 if (!sdev) 366 return -ENXIO; 367 368 /* 369 * If we are in the middle of error recovery, don't let anyone 370 * else try and use this device. Also, if error recovery fails, it 371 * may try and take the device offline, in which case all further 372 * access to the device is prohibited. 373 */ 374 if (!scsi_block_when_processing_errors(sdev)) 375 return -ENODEV; 376 377 /* Check for deprecated ioctls ... all the ioctls which don't 378 * follow the new unique numbering scheme are deprecated */ 379 switch (cmd) { 380 case SCSI_IOCTL_SEND_COMMAND: 381 case SCSI_IOCTL_TEST_UNIT_READY: 382 case SCSI_IOCTL_BENCHMARK_COMMAND: 383 case SCSI_IOCTL_SYNC: 384 case SCSI_IOCTL_START_UNIT: 385 case SCSI_IOCTL_STOP_UNIT: 386 printk(KERN_WARNING "program %s is using a deprecated SCSI " 387 "ioctl, please convert it to SG_IO\n", current->comm); 388 break; 389 default: 390 break; 391 } 392 393 switch (cmd) { 394 case SCSI_IOCTL_GET_IDLUN: 395 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun))) 396 return -EFAULT; 397 398 __put_user((sdev->id & 0xff) 399 + ((sdev->lun & 0xff) << 8) 400 + ((sdev->channel & 0xff) << 16) 401 + ((sdev->host->host_no & 0xff) << 24), 402 &((struct scsi_idlun __user *)arg)->dev_id); 403 __put_user(sdev->host->unique_id, 404 &((struct scsi_idlun __user *)arg)->host_unique_id); 405 return 0; 406 case SCSI_IOCTL_GET_BUS_NUMBER: 407 return put_user(sdev->host->host_no, (int __user *)arg); 408 case SCSI_IOCTL_PROBE_HOST: 409 return ioctl_probe(sdev->host, arg); 410 case SCSI_IOCTL_SEND_COMMAND: 411 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 412 return -EACCES; 413 return scsi_ioctl_send_command(sdev, arg); 414 case SCSI_IOCTL_DOORLOCK: 415 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 416 case SCSI_IOCTL_DOORUNLOCK: 417 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 418 case SCSI_IOCTL_TEST_UNIT_READY: 419 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT, 420 NORMAL_RETRIES); 421 case SCSI_IOCTL_START_UNIT: 422 scsi_cmd[0] = START_STOP; 423 scsi_cmd[1] = 0; 424 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 425 scsi_cmd[4] = 1; 426 return ioctl_internal_command(sdev, scsi_cmd, 427 START_STOP_TIMEOUT, NORMAL_RETRIES); 428 case SCSI_IOCTL_STOP_UNIT: 429 scsi_cmd[0] = START_STOP; 430 scsi_cmd[1] = 0; 431 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 432 scsi_cmd[4] = 0; 433 return ioctl_internal_command(sdev, scsi_cmd, 434 START_STOP_TIMEOUT, NORMAL_RETRIES); 435 case SCSI_IOCTL_GET_PCI: 436 return scsi_ioctl_get_pci(sdev, arg); 437 default: 438 if (sdev->host->hostt->ioctl) 439 return sdev->host->hostt->ioctl(sdev, cmd, arg); 440 } 441 return -EINVAL; 442 } 443 EXPORT_SYMBOL(scsi_ioctl); 444 445 /* 446 * the scsi_nonblock_ioctl() function is designed for ioctls which may 447 * be executed even if the device is in recovery. 448 */ 449 int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd, 450 void __user *arg, struct file *filp) 451 { 452 int val, result; 453 454 /* The first set of iocts may be executed even if we're doing 455 * error processing, as long as the device was opened 456 * non-blocking */ 457 if (filp && filp->f_flags & O_NONBLOCK) { 458 if (scsi_host_in_recovery(sdev->host)) 459 return -ENODEV; 460 } else if (!scsi_block_when_processing_errors(sdev)) 461 return -ENODEV; 462 463 switch (cmd) { 464 case SG_SCSI_RESET: 465 result = get_user(val, (int __user *)arg); 466 if (result) 467 return result; 468 if (val == SG_SCSI_RESET_NOTHING) 469 return 0; 470 switch (val) { 471 case SG_SCSI_RESET_DEVICE: 472 val = SCSI_TRY_RESET_DEVICE; 473 break; 474 case SG_SCSI_RESET_BUS: 475 val = SCSI_TRY_RESET_BUS; 476 break; 477 case SG_SCSI_RESET_HOST: 478 val = SCSI_TRY_RESET_HOST; 479 break; 480 default: 481 return -EINVAL; 482 } 483 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 484 return -EACCES; 485 return (scsi_reset_provider(sdev, val) == 486 SUCCESS) ? 0 : -EIO; 487 } 488 return -ENODEV; 489 } 490 EXPORT_SYMBOL(scsi_nonblockable_ioctl); 491