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 <linux/uaccess.h> 16 17 #include <scsi/scsi.h> 18 #include <scsi/scsi_cmnd.h> 19 #include <scsi/scsi_device.h> 20 #include <scsi/scsi_eh.h> 21 #include <scsi/scsi_host.h> 22 #include <scsi/scsi_ioctl.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, sdev_printk(KERN_INFO, sdev, 95 "Trying ioctl with scsi command %d\n", *cmd)); 96 97 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, 98 &sshdr, timeout, retries, NULL); 99 100 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev, 101 "Ioctl returned 0x%x\n", result)); 102 103 if ((driver_byte(result) & DRIVER_SENSE) && 104 (scsi_sense_valid(&sshdr))) { 105 switch (sshdr.sense_key) { 106 case ILLEGAL_REQUEST: 107 if (cmd[0] == ALLOW_MEDIUM_REMOVAL) 108 sdev->lockable = 0; 109 else 110 sdev_printk(KERN_INFO, sdev, 111 "ioctl_internal_command: " 112 "ILLEGAL REQUEST " 113 "asc=0x%x ascq=0x%x\n", 114 sshdr.asc, sshdr.ascq); 115 break; 116 case NOT_READY: /* This happens if there is no disc in drive */ 117 if (sdev->removable) 118 break; 119 case UNIT_ATTENTION: 120 if (sdev->removable) { 121 sdev->changed = 1; 122 result = 0; /* This is no longer considered an error */ 123 break; 124 } 125 default: /* Fall through for non-removable media */ 126 sdev_printk(KERN_INFO, sdev, 127 "ioctl_internal_command return code = %x\n", 128 result); 129 scsi_print_sense_hdr(sdev, NULL, &sshdr); 130 break; 131 } 132 } 133 134 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev, 135 "IOCTL Releasing command\n")); 136 return result; 137 } 138 139 int scsi_set_medium_removal(struct scsi_device *sdev, char state) 140 { 141 char scsi_cmd[MAX_COMMAND_SIZE]; 142 int ret; 143 144 if (!sdev->removable || !sdev->lockable) 145 return 0; 146 147 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL; 148 scsi_cmd[1] = 0; 149 scsi_cmd[2] = 0; 150 scsi_cmd[3] = 0; 151 scsi_cmd[4] = state; 152 scsi_cmd[5] = 0; 153 154 ret = ioctl_internal_command(sdev, scsi_cmd, 155 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES); 156 if (ret == 0) 157 sdev->locked = (state == SCSI_REMOVAL_PREVENT); 158 return ret; 159 } 160 EXPORT_SYMBOL(scsi_set_medium_removal); 161 162 /* 163 * The scsi_ioctl_get_pci() function places into arg the value 164 * pci_dev::slot_name (8 characters) for the PCI device (if any). 165 * Returns: 0 on success 166 * -ENXIO if there isn't a PCI device pointer 167 * (could be because the SCSI driver hasn't been 168 * updated yet, or because it isn't a SCSI 169 * device) 170 * any copy_to_user() error on failure there 171 */ 172 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg) 173 { 174 struct device *dev = scsi_get_device(sdev->host); 175 const char *name; 176 177 if (!dev) 178 return -ENXIO; 179 180 name = dev_name(dev); 181 182 /* compatibility with old ioctl which only returned 183 * 20 characters */ 184 return copy_to_user(arg, name, min(strlen(name), (size_t)20)) 185 ? -EFAULT: 0; 186 } 187 188 189 /** 190 * scsi_ioctl - Dispatch ioctl to scsi device 191 * @sdev: scsi device receiving ioctl 192 * @cmd: which ioctl is it 193 * @arg: data associated with ioctl 194 * 195 * Description: The scsi_ioctl() function differs from most ioctls in that it 196 * does not take a major/minor number as the dev field. Rather, it takes 197 * a pointer to a &struct scsi_device. 198 */ 199 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg) 200 { 201 char scsi_cmd[MAX_COMMAND_SIZE]; 202 struct scsi_sense_hdr sense_hdr; 203 204 /* Check for deprecated ioctls ... all the ioctls which don't 205 * follow the new unique numbering scheme are deprecated */ 206 switch (cmd) { 207 case SCSI_IOCTL_SEND_COMMAND: 208 case SCSI_IOCTL_TEST_UNIT_READY: 209 case SCSI_IOCTL_BENCHMARK_COMMAND: 210 case SCSI_IOCTL_SYNC: 211 case SCSI_IOCTL_START_UNIT: 212 case SCSI_IOCTL_STOP_UNIT: 213 printk(KERN_WARNING "program %s is using a deprecated SCSI " 214 "ioctl, please convert it to SG_IO\n", current->comm); 215 break; 216 default: 217 break; 218 } 219 220 switch (cmd) { 221 case SCSI_IOCTL_GET_IDLUN: 222 if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun))) 223 return -EFAULT; 224 225 __put_user((sdev->id & 0xff) 226 + ((sdev->lun & 0xff) << 8) 227 + ((sdev->channel & 0xff) << 16) 228 + ((sdev->host->host_no & 0xff) << 24), 229 &((struct scsi_idlun __user *)arg)->dev_id); 230 __put_user(sdev->host->unique_id, 231 &((struct scsi_idlun __user *)arg)->host_unique_id); 232 return 0; 233 case SCSI_IOCTL_GET_BUS_NUMBER: 234 return put_user(sdev->host->host_no, (int __user *)arg); 235 case SCSI_IOCTL_PROBE_HOST: 236 return ioctl_probe(sdev->host, arg); 237 case SCSI_IOCTL_SEND_COMMAND: 238 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO)) 239 return -EACCES; 240 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg); 241 case SCSI_IOCTL_DOORLOCK: 242 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 243 case SCSI_IOCTL_DOORUNLOCK: 244 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 245 case SCSI_IOCTL_TEST_UNIT_READY: 246 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT, 247 NORMAL_RETRIES, &sense_hdr); 248 case SCSI_IOCTL_START_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] = 1; 253 return ioctl_internal_command(sdev, scsi_cmd, 254 START_STOP_TIMEOUT, NORMAL_RETRIES); 255 case SCSI_IOCTL_STOP_UNIT: 256 scsi_cmd[0] = START_STOP; 257 scsi_cmd[1] = 0; 258 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0; 259 scsi_cmd[4] = 0; 260 return ioctl_internal_command(sdev, scsi_cmd, 261 START_STOP_TIMEOUT, NORMAL_RETRIES); 262 case SCSI_IOCTL_GET_PCI: 263 return scsi_ioctl_get_pci(sdev, arg); 264 case SG_SCSI_RESET: 265 return scsi_ioctl_reset(sdev, arg); 266 default: 267 if (sdev->host->hostt->ioctl) 268 return sdev->host->hostt->ioctl(sdev, cmd, arg); 269 } 270 return -EINVAL; 271 } 272 EXPORT_SYMBOL(scsi_ioctl); 273 274 /* 275 * We can process a reset even when a device isn't fully operable. 276 */ 277 int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd, 278 bool ndelay) 279 { 280 if (cmd == SG_SCSI_RESET && ndelay) { 281 if (scsi_host_in_recovery(sdev->host)) 282 return -EAGAIN; 283 } else { 284 if (!scsi_block_when_processing_errors(sdev)) 285 return -ENODEV; 286 } 287 288 return 0; 289 } 290 EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors); 291