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
 12static 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
 94out_put_request:
 95	blk_mq_free_request(rq);
 96	return ret;
 97}
 98
 99struct 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}