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 
scsi_bsg_sg_io_fn(struct request_queue * q,struct sg_io_v4 * hdr,fmode_t mode,unsigned int timeout)12 static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
13 		fmode_t mode, 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, mode))
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 
scsi_bsg_register_queue(struct scsi_device * sdev)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 }
104