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}
104