drivers/scsi/scsi_bsg.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bsg.h>
   3 #include <scsi/scsi.h>
   4 #include <scsi/scsi_ioctl.h>
   5 #include <scsi/scsi_cmnd.h>
   6 #include <scsi/scsi_device.h>
   7 #include <scsi/sg.h>
   8 #include "scsi_priv.h"
   9
  10 #define uptr64(val) ((void __user *)(uintptr_t)(val))
  11
  12 static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
  13                 bool open_for_write, unsigned int timeout)
  14 {
  15         struct scsi_cmnd *scmd;
  16         struct request *rq;
  17         struct bio *bio;
  18         int ret;
  19
  20         if (hdr->protocol != BSG_PROTOCOL_SCSI  ||
  21             hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)
  22                 return -EINVAL;
  23         if (hdr->dout_xfer_len && hdr->din_xfer_len) {
  24                 pr_warn_once("BIDI support in bsg has been removed.\n");
  25                 return -EOPNOTSUPP;
  26         }
  27
  28         rq = scsi_alloc_request(q, hdr->dout_xfer_len ?
  29                                 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
  30         if (IS_ERR(rq))
  31                 return PTR_ERR(rq);
  32         rq->timeout = timeout;
  33
  34         scmd = blk_mq_rq_to_pdu(rq);
  35         scmd->cmd_len = hdr->request_len;
  36         if (scmd->cmd_len > sizeof(scmd->cmnd)) {
  37                 ret = -EINVAL;
  38                 goto out_put_request;
  39         }
  40
  41         ret = -EFAULT;
  42         if (copy_from_user(scmd->cmnd, uptr64(hdr->request), scmd->cmd_len))
  43                 goto out_put_request;
  44         ret = -EPERM;
  45         if (!scsi_cmd_allowed(scmd->cmnd, open_for_write))
  46                 goto out_put_request;
  47
  48         ret = 0;
  49         if (hdr->dout_xfer_len) {
  50                 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
  51                                 hdr->dout_xfer_len, GFP_KERNEL);
  52         } else if (hdr->din_xfer_len) {
  53                 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
  54                                 hdr->din_xfer_len, GFP_KERNEL);
  55         }
  56
  57         if (ret)
  58                 goto out_put_request;
  59
  60         bio = rq->bio;
  61         blk_execute_rq(rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
  62
  63         /*
  64          * fill in all the output members
  65          */
  66         hdr->device_status = scmd->result & 0xff;
  67         hdr->transport_status = host_byte(scmd->result);
  68         hdr->driver_status = 0;
  69         if (scsi_status_is_check_condition(scmd->result))
  70                 hdr->driver_status = DRIVER_SENSE;
  71         hdr->info = 0;
  72         if (hdr->device_status || hdr->transport_status || hdr->driver_status)
  73                 hdr->info |= SG_INFO_CHECK;
  74         hdr->response_len = 0;
  75
  76         if (scmd->sense_len && hdr->response) {
  77                 int len = min_t(unsigned int, hdr->max_response_len,
  78                                 scmd->sense_len);
  79
  80                 if (copy_to_user(uptr64(hdr->response), scmd->sense_buffer,
  81                                  len))
  82                         ret = -EFAULT;
  83                 else
  84                         hdr->response_len = len;
  85         }
  86
  87         if (rq_data_dir(rq) == READ)
  88                 hdr->din_resid = scmd->resid_len;
  89         else
  90                 hdr->dout_resid = scmd->resid_len;
  91
  92         blk_rq_unmap_user(bio);
  93
  94 out_put_request:
  95         blk_mq_free_request(rq);
  96         return ret;
  97 }
  98
  99 struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
 100 {
 101         return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
 102                         dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
 103 }