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, opf: hdr->dout_xfer_len ?
29 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, flags: 0);
30 if (IS_ERR(ptr: rq))
31 return PTR_ERR(ptr: 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(to: scmd->cmnd, uptr64(hdr->request), n: scmd->cmd_len))
43 goto out_put_request;
44 ret = -EPERM;
45 if (!scsi_cmd_allowed(cmd: 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, at_head: !(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(status: 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), from: scmd->sense_buffer,
81 n: 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(q: sdev->request_queue, parent: &sdev->sdev_gendev,
102 name: dev_name(dev: &sdev->sdev_gendev), sg_io_fn: scsi_bsg_sg_io_fn);
103}
104