Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 1b59b27e887fd74cf629bbee05ddc76dd906f194 (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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
/*
 *  scsi_netlink.c  - SCSI Transport Netlink Interface
 *
 *  Copyright (C) 2006   James Smart, Emulex Corporation
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
#include <linux/time.h>
#include <linux/jiffies.h>
#include <linux/security.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. Extracts message from a receive buffer.
 *    Validates message header and calls appropriate transport message handler
 *
 * @skb:		socket receive buffer
 *
 **/
static void
scsi_nl_rcv_msg(struct sk_buff *skb)
{
	struct nlmsghdr *nlh;
	struct scsi_nl_hdr *hdr;
	uint32_t rlen;
	int err;

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

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

		/*
		 * We currently don't support anyone sending us a message
		 */

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

		skb_pull(skb, rlen);
	}
}


/**
 * scsi_nl_rcv_msg -
 *    Receive handler for a socket. Extracts a received message buffer from
 *    the socket, and starts message processing.
 *
 * @sk:		socket
 * @len:	unused
 *
 **/
static void
scsi_nl_rcv(struct sock *sk, int len)
{
	struct sk_buff *skb;

	while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
		scsi_nl_rcv_msg(skb);
		kfree_skb(skb);
	}
}


/**
 * scsi_nl_rcv_event -
 *    Event handler for a netlink socket.
 *
 * @this:		event notifier block
 * @event:		event type
 * @ptr:		event payload
 *
 **/
static int
scsi_nl_rcv_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct netlink_notify *n = ptr;

	if (n->protocol != NETLINK_SCSITRANSPORT)
		return NOTIFY_DONE;

	/*
	 * Currently, we are not tracking PID's, etc. There is nothing
	 * to handle.
	 */

	return NOTIFY_DONE;
}

static struct notifier_block scsi_netlink_notifier = {
	.notifier_call  = scsi_nl_rcv_event,
};


/**
 * scsi_netlink_init -
 *    Called by SCSI subsystem to intialize the SCSI transport netlink
 *    interface
 *
 **/
void
scsi_netlink_init(void)
{
	int error;

	error = netlink_register_notifier(&scsi_netlink_notifier);
	if (error) {
		printk(KERN_ERR "%s: register of event handler failed - %d\n",
				__FUNCTION__, error);
		return;
	}

	scsi_nl_sock = netlink_kernel_create(NETLINK_SCSITRANSPORT,
				SCSI_NL_GRP_CNT, scsi_nl_rcv, THIS_MODULE);
	if (!scsi_nl_sock) {
		printk(KERN_ERR "%s: register of recieve handler failed\n",
				__FUNCTION__);
		netlink_unregister_notifier(&scsi_netlink_notifier);
	}

	return;
}


/**
 * scsi_netlink_exit -
 *    Called by SCSI subsystem to disable the SCSI transport netlink
 *    interface
 *
 **/
void
scsi_netlink_exit(void)
{
	if (scsi_nl_sock) {
		sock_release(scsi_nl_sock->sk_socket);
		netlink_unregister_notifier(&scsi_netlink_notifier);
	}

	return;
}