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 (result < 0) 105 goto out; 106 if (scsi_sense_valid(&sshdr)) { 107 switch (sshdr.sense_key) { 108 case ILLEGAL_REQUEST: 109 if (cmd[0] == ALLOW_MEDIUM_REMOVAL) 110 sdev->lockable = 0; 111 else 112 sdev_printk(KERN_INFO, sdev, 113 "ioctl_internal_command: " 114 "ILLEGAL REQUEST " 115 "asc=0x%x ascq=0x%x\n", 116 sshdr.asc, sshdr.ascq); 117 break; 118 case NOT_READY: /* This happens if there is no disc in drive */ 119 if (sdev->removable) 120 break; 121 fallthrough; 122 case UNIT_ATTENTION: 123 if (sdev->removable) { 124 sdev->changed = 1; 125 result = 0; /* This is no longer considered an error */ 126 break; 127 } 128 fallthrough; /* for non-removable media */ 129 default: 130 sdev_printk(KERN_INFO, sdev, 131 "ioctl_internal_command return code = %x\n", 132 result); 133 scsi_print_sense_hdr(sdev, NULL, &sshdr); 134 break; 135 } 136 } 137 out: 138 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev, 139 "IOCTL Releasing command\n")); 140 return result; 141 } 142 143 int scsi_set_medium_removal(struct scsi_device *sdev, char state) 144 { 145 char scsi_cmd[MAX_COMMAND_SIZE]; 146 int ret; 147 148 if (!sdev->removable || !sdev->lockable) 149 return 0; 150 151 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL; 152 scsi_cmd[1] = 0; 153 scsi_cmd[2] = 0; 154 scsi_cmd[3] = 0; 155 scsi_cmd[4] = state; 156 scsi_cmd[5] = 0; 157 158 ret = ioctl_internal_command(sdev, scsi_cmd, 159 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES); 160 if (ret == 0) 161 sdev->locked = (state == SCSI_REMOVAL_PREVENT); 162 return ret; 163 } 164 EXPORT_SYMBOL(scsi_set_medium_removal); 165 166 /* 167 * The scsi_ioctl_get_pci() function places into arg the value 168 * pci_dev::slot_name (8 characters) for the PCI device (if any). 169 * Returns: 0 on success 170 * -ENXIO if there isn't a PCI device pointer 171 * (could be because the SCSI driver hasn't been 172 * updated yet, or because it isn't a SCSI 173 * device) 174 * any copy_to_user() error on failure there 175 */ 176 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg) 177 { 178 struct device *dev = scsi_get_device(sdev->host); 179 const char *name; 180 181 if (!dev) 182 return -ENXIO; 183 184 name = dev_name(dev); 185 186 /* compatibility with old ioctl which only returned 187 * 20 characters */ 188 return copy_to_user(arg, name, min(strlen(name), (size_t)20)) 189 ? -EFAULT: 0; 190 } 191 192 193 static int scsi_ioctl_common(struct scsi_device *sdev, int cmd, void __user *arg) 194 { 195 char scsi_cmd[MAX_COMMAND_SIZE]; 196 struct scsi_sense_hdr sense_hdr; 197 198 /* Check for deprecated ioctls ... all the ioctls which don't 199 * follow the new unique numbering scheme are deprecated */ 200 switch (cmd) { 201 case SCSI_IOCTL_SEND_COMMAND: 202 case SCSI_IOCTL_TEST_UNIT_READY: 203 case SCSI_IOCTL_BENCHMARK_COMMAND: 204 case SCSI_IOCTL_SYNC: 205 case SCSI_IOCTL_START_UNIT: 206 case SCSI_IOCTL_STOP_UNIT: 207 printk(KERN_WARNING "program %s is using a deprecated SCSI " 208 "ioctl, please convert it to SG_IO\n", current->comm); 209 break; 210 default: 211 break; 212 } 213 214 switch (cmd) { 215 case SCSI_IOCTL_GET_IDLUN: { 216 struct scsi_idlun v = { 217 .dev_id = (sdev->id & 0xff) 218 + ((sdev->lun & 0xff) << 8) 219 + ((sdev->channel & 0xff) << 16) 220 + ((sdev->host->host_no & 0xff) << 24), 221 .host_unique_id = sdev->host->unique_id 222 }; 223 if (copy_to_user(arg, &v, sizeof(struct scsi_idlun))) 224 return -EFAULT; 225 return 0; 226 } 227 case SCSI_IOCTL_GET_BUS_NUMBER: 228 return put_user(sdev->host->host_no, (int __user *)arg); 229 case SCSI_IOCTL_PROBE_HOST: 230 return ioctl_probe(sdev->host, arg); 231 case SCSI_IOCTL_SEND_COMMAND: 232 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 233 return -EACCES; 234 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg); 235 case SCSI_IOCTL_DOORLOCK: 236 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 237 case SCSI_IOCTL_DOORUNLOCK: 238 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 239 case SCSI_IOCTL_TEST_UNIT_READY: 240 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT, 241 NORMAL_RETRIES, &sense_hdr); 242 case SCSI_IOCTL_START_UNIT: 243 scsi_cmd[0] = START_STOP; 244 scsi_cmd[1] = 0; 245 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 246 scsi_cmd[4] = 1; 247 return ioctl_internal_command(sdev, scsi_cmd, 248 START_STOP_TIMEOUT, NORMAL_RETRIES); 249 case SCSI_IOCTL_STOP_UNIT: 250 scsi_cmd[0] = START_STOP; 251 scsi_cmd[1] = 0; 252 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 253 scsi_cmd[4] = 0; 254 return ioctl_internal_command(sdev, scsi_cmd, 255 START_STOP_TIMEOUT, NORMAL_RETRIES); 256 case SCSI_IOCTL_GET_PCI: 257 return scsi_ioctl_get_pci(sdev, arg); 258 case SG_SCSI_RESET: 259 return scsi_ioctl_reset(sdev, arg); 260 } 261 return -ENOIOCTLCMD; 262 } 263 264 /** 265 * scsi_ioctl - Dispatch ioctl to scsi device 266 * @sdev: scsi device receiving ioctl 267 * @cmd: which ioctl is it 268 * @arg: data associated with ioctl 269 * 270 * Description: The scsi_ioctl() function differs from most ioctls in that it 271 * does not take a major/minor number as the dev field. Rather, it takes 272 * a pointer to a &struct scsi_device. 273 */ 274 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 275 { 276 int ret = scsi_ioctl_common(sdev, cmd, arg); 277 278 if (ret != -ENOIOCTLCMD) 279 return ret; 280 281 if (sdev->host->hostt->ioctl) 282 return sdev->host->hostt->ioctl(sdev, cmd, arg); 283 284 return -EINVAL; 285 } 286 EXPORT_SYMBOL(scsi_ioctl); 287 288 #ifdef CONFIG_COMPAT 289 int scsi_compat_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 290 { 291 int ret = scsi_ioctl_common(sdev, cmd, arg); 292 293 if (ret != -ENOIOCTLCMD) 294 return ret; 295 296 if (sdev->host->hostt->compat_ioctl) 297 return sdev->host->hostt->compat_ioctl(sdev, cmd, arg); 298 299 return ret; 300 } 301 EXPORT_SYMBOL(scsi_compat_ioctl); 302 #endif 303 304 /* 305 * We can process a reset even when a device isn't fully operable. 306 */ 307 int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd, 308 bool ndelay) 309 { 310 if (cmd == SG_SCSI_RESET && ndelay) { 311 if (scsi_host_in_recovery(sdev->host)) 312 return -EAGAIN; 313 } else { 314 if (!scsi_block_when_processing_errors(sdev)) 315 return -ENODEV; 316 } 317 318 return 0; 319 } 320 EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors); 321