summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/scsi_netlink.c
blob: d7f76fd84256afbf2a954bf68ab5b7bdb97e87d3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  scsi_netlink.c  - SCSI Transport Netlink Interface
 *
 *  Copyright (C) 2006   James Smart, Emulex Corporation
 */
#include <linux/time.h>
#include <linux/jiffies.h>
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/netlink.h>

#include <scsi/scsi_netlink.h>
#include "scsi_priv.h"

struct sock *scsi_nl_sock = NULL;
EXPORT_SYMBOL_GPL(scsi_nl_sock);

/**
 * scsi_nl_rcv_msg - Receive message handler.
 * @skb:		socket receive buffer
 *
 * Description: Extracts message from a receive buffer.
 *    Validates message header and calls appropriate transport message handler
 *
 *
 **/
static void
scsi_nl_rcv_msg(struct sk_buff *skb)
{
	struct nlmsghdr *nlh;
	struct scsi_nl_hdr *hdr;
	u32 rlen;
	int err, tport;

	while (skb->len >= NLMSG_HDRLEN) {
		err = 0;

		nlh = nlmsg_hdr(skb);
		if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) ||
		    (skb->len < nlh->nlmsg_len)) {
			printk(KERN_WARNING "%s: discarding partial skb\n",
				 __func__);
			return;
		}

		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
		if (rlen > skb->len)
			rlen = skb->len;

		if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
			err = -EBADMSG;
			goto next_msg;
		}

		hdr = nlmsg_data(nlh);
		if ((hdr->version != SCSI_NL_VERSION) ||
		    (hdr->magic != SCSI_NL_MAGIC)) {
			err = -EPROTOTYPE;
			goto next_msg;
		}

		if (!netlink_capable(skb, CAP_SYS_ADMIN)) {
			err = -EPERM;
			goto next_msg;
		}

		if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
			printk(KERN_WARNING "%s: discarding partial message\n",
				 __func__);
			goto next_msg;
		}

		/*
		 * Deliver message to the appropriate transport
		 */
		tport = hdr->transport;
		if (tport == SCSI_NL_TRANSPORT) {
			switch (hdr->msgtype) {
			case SCSI_NL_SHOST_VENDOR:
				/* Locate the driver that corresponds to the message */
				err = -ESRCH;
				break;
			default:
				err = -EBADR;
				break;
			}
			if (err)
				printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
				       __func__, hdr->msgtype, err);
		}
		else
			err = -ENOENT;

next_msg:
		if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
			netlink_ack(skb, nlh, err, NULL);

		skb_pull(skb, rlen);
	}
}

/**
 * scsi_netlink_init - Called by SCSI subsystem to initialize
 * 	the SCSI transport netlink interface
 *
 **/
void
scsi_netlink_init(void)
{
	struct netlink_kernel_cfg cfg = {
		.input	= scsi_nl_rcv_msg,
		.groups	= SCSI_NL_GRP_CNT,
	};

	scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
					     &cfg);
	if (!scsi_nl_sock) {
		printk(KERN_ERR "%s: register of receive handler failed\n",
				__func__);
		return;
	}

	return;
}


/**
 * scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
 *
 **/
void
scsi_netlink_exit(void)
{
	if (scsi_nl_sock) {
		netlink_kernel_release(scsi_nl_sock);
	}

	return;
}

OpenPOWER on IntegriCloud