1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Changes: 4 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000 5 * - get rid of some verify_areas and use __copy*user and __get/put_user 6 * for the ones that remain 7 */ 8 #include <linux/module.h> 9 #include <linux/blkdev.h> 10 #include <linux/interrupt.h> 11 #include <linux/errno.h> 12 #include <linux/kernel.h> 13 #include <linux/sched.h> 14 #include <linux/mm.h> 15 #include <linux/string.h> 16 #include <linux/uaccess.h> 17 18 #include <scsi/scsi.h> 19 #include <scsi/scsi_cmnd.h> 20 #include <scsi/scsi_device.h> 21 #include <scsi/scsi_eh.h> 22 #include <scsi/scsi_host.h> 23 #include <scsi/scsi_ioctl.h> 24 #include <scsi/sg.h> 25 #include <scsi/scsi_dbg.h> 26 27 #include "scsi_logging.h" 28 29 #define NORMAL_RETRIES 5 30 #define IOCTL_NORMAL_TIMEOUT (10 * HZ) 31 32 #define MAX_BUF PAGE_SIZE 33 34 /** 35 * ioctl_probe -- return host identification 36 * @host: host to identify 37 * @buffer: userspace buffer for identification 38 * 39 * Return an identifying string at @buffer, if @buffer is non-NULL, filling 40 * to the length stored at * (int *) @buffer. 41 */ 42 static int ioctl_probe(struct Scsi_Host *host, void __user *buffer) 43 { 44 unsigned int len, slen; 45 const char *string; 46 47 if (buffer) { 48 if (get_user(len, (unsigned int __user *) buffer)) 49 return -EFAULT; 50 51 if (host->hostt->info) 52 string = host->hostt->info(host); 53 else 54 string = host->hostt->name; 55 if (string) { 56 slen = strlen(string); 57 if (len > slen) 58 len = slen + 1; 59 if (copy_to_user(buffer, string, len)) 60 return -EFAULT; 61 } 62 } 63 return 1; 64 } 65 66 /* 67 68 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host. 69 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used. 70 * 71 * dev is the SCSI device struct ptr, *(int *) arg is the length of the 72 * input data, if any, not including the command string & counts, 73 * *((int *)arg + 1) is the output buffer size in bytes. 74 * 75 * *(char *) ((int *) arg)[2] the actual command byte. 76 * 77 * Note that if more than MAX_BUF bytes are requested to be transferred, 78 * the ioctl will fail with error EINVAL. 79 * 80 * This size *does not* include the initial lengths that were passed. 81 * 82 * The SCSI command is read from the memory location immediately after the 83 * length words, and the input data is right after the command. The SCSI 84 * routines know the command size based on the opcode decode. 85 * 86 * The output area is then filled in starting from the command byte. 87 */ 88 89 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd, 90 int timeout, int retries) 91 { 92 int result; 93 struct scsi_sense_hdr sshdr; 94 95 SCSI_LOG_IOCTL(1, sdev_printk(KERN_INFO, sdev, 96 "Trying ioctl with scsi command %d\n", *cmd)); 97 98 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, 99 &sshdr, timeout, retries, NULL); 100 101 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev, 102 "Ioctl returned 0x%x\n", result)); 103 104 if (driver_byte(result) == DRIVER_SENSE && 105 scsi_sense_valid(&sshdr)) { 106 switch (sshdr.sense_key) { 107 case ILLEGAL_REQUEST: 108 if (cmd[0] == ALLOW_MEDIUM_REMOVAL) 109 sdev->lockable = 0; 110 else 111 sdev_printk(KERN_INFO, sdev, 112 "ioctl_internal_command: " 113 "ILLEGAL REQUEST " 114 "asc=0x%x ascq=0x%x\n", 115 sshdr.asc, sshdr.ascq); 116 break; 117 case NOT_READY: /* This happens if there is no disc in drive */ 118 if (sdev->removable) 119 break; 120 /* FALLTHROUGH */ 121 case UNIT_ATTENTION: 122 if (sdev->removable) { 123 sdev->changed = 1; 124 result = 0; /* This is no longer considered an error */ 125 break; 126 } 127 /* FALLTHROUGH -- for non-removable media */ 128 default: 129 sdev_printk(KERN_INFO, sdev, 130 "ioctl_internal_command return code = %x\n", 131 result); 132 scsi_print_sense_hdr(sdev, NULL, &sshdr); 133 break; 134 } 135 } 136 137 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev, 138 "IOCTL Releasing command\n")); 139 return result; 140 } 141 142 int scsi_set_medium_removal(struct scsi_device *sdev, char state) 143 { 144 char scsi_cmd[MAX_COMMAND_SIZE]; 145 int ret; 146 147 if (!sdev->removable || !sdev->lockable) 148 return 0; 149 150 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL; 151 scsi_cmd[1] = 0; 152 scsi_cmd[2] = 0; 153 scsi_cmd[3] = 0; 154 scsi_cmd[4] = state; 155 scsi_cmd[5] = 0; 156 157 ret = ioctl_internal_command(sdev, scsi_cmd, 158 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES); 159 if (ret == 0) 160 sdev->locked = (state == SCSI_REMOVAL_PREVENT); 161 return ret; 162 } 163 EXPORT_SYMBOL(scsi_set_medium_removal); 164 165 /* 166 * The scsi_ioctl_get_pci() function places into arg the value 167 * pci_dev::slot_name (8 characters) for the PCI device (if any). 168 * Returns: 0 on success 169 * -ENXIO if there isn't a PCI device pointer 170 * (could be because the SCSI driver hasn't been 171 * updated yet, or because it isn't a SCSI 172 * device) 173 * any copy_to_user() error on failure there 174 */ 175 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg) 176 { 177 struct device *dev = scsi_get_device(sdev->host); 178 const char *name; 179 180 if (!dev) 181 return -ENXIO; 182 183 name = dev_name(dev); 184 185 /* compatibility with old ioctl which only returned 186 * 20 characters */ 187 return copy_to_user(arg, name, min(strlen(name), (size_t)20)) 188 ? -EFAULT: 0; 189 } 190 191 192 static int scsi_ioctl_common(struct scsi_device *sdev, int cmd, void __user *arg) 193 { 194 char scsi_cmd[MAX_COMMAND_SIZE]; 195 struct scsi_sense_hdr sense_hdr; 196 197 /* Check for deprecated ioctls ... all the ioctls which don't 198 * follow the new unique numbering scheme are deprecated */ 199 switch (cmd) { 200 case SCSI_IOCTL_SEND_COMMAND: 201 case SCSI_IOCTL_TEST_UNIT_READY: 202 case SCSI_IOCTL_BENCHMARK_COMMAND: 203 case SCSI_IOCTL_SYNC: 204 case SCSI_IOCTL_START_UNIT: 205 case SCSI_IOCTL_STOP_UNIT: 206 printk(KERN_WARNING "program %s is using a deprecated SCSI " 207 "ioctl, please convert it to SG_IO\n", current->comm); 208 break; 209 default: 210 break; 211 } 212 213 switch (cmd) { 214 case SCSI_IOCTL_GET_IDLUN: { 215 struct scsi_idlun v = { 216 .dev_id = (sdev->id & 0xff) 217 + ((sdev->lun & 0xff) << 8) 218 + ((sdev->channel & 0xff) << 16) 219 + ((sdev->host->host_no & 0xff) << 24), 220 .host_unique_id = sdev->host->unique_id 221 }; 222 if (copy_to_user(arg, &v, sizeof(struct scsi_idlun))) 223 return -EFAULT; 224 return 0; 225 } 226 case SCSI_IOCTL_GET_BUS_NUMBER: 227 return put_user(sdev->host->host_no, (int __user *)arg); 228 case SCSI_IOCTL_PROBE_HOST: 229 return ioctl_probe(sdev->host, arg); 230 case SCSI_IOCTL_SEND_COMMAND: 231 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 232 return -EACCES; 233 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg); 234 case SCSI_IOCTL_DOORLOCK: 235 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 236 case SCSI_IOCTL_DOORUNLOCK: 237 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 238 case SCSI_IOCTL_TEST_UNIT_READY: 239 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT, 240 NORMAL_RETRIES, &sense_hdr); 241 case SCSI_IOCTL_START_UNIT: 242 scsi_cmd[0] = START_STOP; 243 scsi_cmd[1] = 0; 244 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 245 scsi_cmd[4] = 1; 246 return ioctl_internal_command(sdev, scsi_cmd, 247 START_STOP_TIMEOUT, NORMAL_RETRIES); 248 case SCSI_IOCTL_STOP_UNIT: 249 scsi_cmd[0] = START_STOP; 250 scsi_cmd[1] = 0; 251 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 252 scsi_cmd[4] = 0; 253 return ioctl_internal_command(sdev, scsi_cmd, 254 START_STOP_TIMEOUT, NORMAL_RETRIES); 255 case SCSI_IOCTL_GET_PCI: 256 return scsi_ioctl_get_pci(sdev, arg); 257 case SG_SCSI_RESET: 258 return scsi_ioctl_reset(sdev, arg); 259 } 260 return -ENOIOCTLCMD; 261 } 262 263 /** 264 * scsi_ioctl - Dispatch ioctl to scsi device 265 * @sdev: scsi device receiving ioctl 266 * @cmd: which ioctl is it 267 * @arg: data associated with ioctl 268 * 269 * Description: The scsi_ioctl() function differs from most ioctls in that it 270 * does not take a major/minor number as the dev field. Rather, it takes 271 * a pointer to a &struct scsi_device. 272 */ 273 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 274 { 275 int ret = scsi_ioctl_common(sdev, cmd, arg); 276 277 if (ret != -ENOIOCTLCMD) 278 return ret; 279 280 if (sdev->host->hostt->ioctl) 281 return sdev->host->hostt->ioctl(sdev, cmd, arg); 282 283 return -EINVAL; 284 } 285 EXPORT_SYMBOL(scsi_ioctl); 286 287 #ifdef CONFIG_COMPAT 288 int scsi_compat_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 289 { 290 int ret = scsi_ioctl_common(sdev, cmd, arg); 291 292 if (ret != -ENOIOCTLCMD) 293 return ret; 294 295 if (sdev->host->hostt->compat_ioctl) 296 return sdev->host->hostt->compat_ioctl(sdev, cmd, arg); 297 298 return ret; 299 } 300 EXPORT_SYMBOL(scsi_compat_ioctl); 301 #endif 302 303 /* 304 * We can process a reset even when a device isn't fully operable. 305 */ 306 int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd, 307 bool ndelay) 308 { 309 if (cmd == SG_SCSI_RESET && ndelay) { 310 if (scsi_host_in_recovery(sdev->host)) 311 return -EAGAIN; 312 } else { 313 if (!scsi_block_when_processing_errors(sdev)) 314 return -ENODEV; 315 } 316 317 return 0; 318 } 319 EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors); 320