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_request *sreq;
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 ret = -ENOMEM;
35 sreq = scsi_req(rq);
36 sreq->cmd_len = hdr->request_len;
37 if (sreq->cmd_len > BLK_MAX_CDB) {
38 sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL);
39 if (!sreq->cmd)
40 goto out_put_request;
41 }
42
43 ret = -EFAULT;
44 if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len))
45 goto out_free_cmd;
46 ret = -EPERM;
47 if (!scsi_cmd_allowed(sreq->cmd, mode))
48 goto out_free_cmd;
49
50 ret = 0;
51 if (hdr->dout_xfer_len) {
52 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
53 hdr->dout_xfer_len, GFP_KERNEL);
54 } else if (hdr->din_xfer_len) {
55 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
56 hdr->din_xfer_len, GFP_KERNEL);
57 }
58
59 if (ret)
60 goto out_free_cmd;
61
62 bio = rq->bio;
63 blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
64
65 /*
66 * fill in all the output members
67 */
68 hdr->device_status = sreq->result & 0xff;
69 hdr->transport_status = host_byte(sreq->result);
70 hdr->driver_status = 0;
71 if (scsi_status_is_check_condition(sreq->result))
72 hdr->driver_status = DRIVER_SENSE;
73 hdr->info = 0;
74 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
75 hdr->info |= SG_INFO_CHECK;
76 hdr->response_len = 0;
77
78 if (sreq->sense_len && hdr->response) {
79 int len = min_t(unsigned int, hdr->max_response_len,
80 sreq->sense_len);
81
82 if (copy_to_user(uptr64(hdr->response), sreq->sense, len))
83 ret = -EFAULT;
84 else
85 hdr->response_len = len;
86 }
87
88 if (rq_data_dir(rq) == READ)
89 hdr->din_resid = sreq->resid_len;
90 else
91 hdr->dout_resid = sreq->resid_len;
92
93 blk_rq_unmap_user(bio);
94
95 out_free_cmd:
96 scsi_req_free_cmd(scsi_req(rq));
97 out_put_request:
98 blk_mq_free_request(rq);
99 return ret;
100 }
101
scsi_bsg_register_queue(struct scsi_device * sdev)102 struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev)
103 {
104 return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev,
105 dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn);
106 }
107