blob: 4bf9aa547c78cebbce7096bef1d4632c9a9abe8f [file] [log] [blame]
James Smart84314fd2006-08-18 17:30:09 -04001/*
2 * scsi_netlink.c - SCSI Transport Netlink Interface
3 *
4 * Copyright (C) 2006 James Smart, Emulex Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21#include <linux/time.h>
22#include <linux/jiffies.h>
23#include <linux/security.h>
24#include <net/sock.h>
25#include <net/netlink.h>
26
27#include <scsi/scsi_netlink.h>
28#include "scsi_priv.h"
29
30struct sock *scsi_nl_sock = NULL;
31EXPORT_SYMBOL_GPL(scsi_nl_sock);
32
33
34/**
35 * scsi_nl_rcv_msg -
36 * Receive message handler. Extracts message from a receive buffer.
37 * Validates message header and calls appropriate transport message handler
38 *
39 * @skb: socket receive buffer
40 *
41 **/
42static void
43scsi_nl_rcv_msg(struct sk_buff *skb)
44{
45 struct nlmsghdr *nlh;
46 struct scsi_nl_hdr *hdr;
47 uint32_t rlen;
48 int err;
49
50 while (skb->len >= NLMSG_SPACE(0)) {
51 err = 0;
52
Arnaldo Carvalho de Melob529ccf2007-04-25 19:08:35 -070053 nlh = nlmsg_hdr(skb);
James Smart84314fd2006-08-18 17:30:09 -040054 if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) ||
55 (skb->len < nlh->nlmsg_len)) {
56 printk(KERN_WARNING "%s: discarding partial skb\n",
57 __FUNCTION__);
58 return;
59 }
60
61 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
62 if (rlen > skb->len)
63 rlen = skb->len;
64
65 if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
66 err = -EBADMSG;
67 goto next_msg;
68 }
69
70 hdr = NLMSG_DATA(nlh);
71 if ((hdr->version != SCSI_NL_VERSION) ||
72 (hdr->magic != SCSI_NL_MAGIC)) {
73 err = -EPROTOTYPE;
74 goto next_msg;
75 }
76
77 if (security_netlink_recv(skb, CAP_SYS_ADMIN)) {
78 err = -EPERM;
79 goto next_msg;
80 }
81
82 if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
83 printk(KERN_WARNING "%s: discarding partial message\n",
84 __FUNCTION__);
85 return;
86 }
87
88 /*
89 * We currently don't support anyone sending us a message
90 */
91
92next_msg:
93 if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
94 netlink_ack(skb, nlh, err);
95
96 skb_pull(skb, rlen);
97 }
98}
99
100
101/**
102 * scsi_nl_rcv_msg -
103 * Receive handler for a socket. Extracts a received message buffer from
104 * the socket, and starts message processing.
105 *
106 * @sk: socket
107 * @len: unused
108 *
109 **/
110static void
111scsi_nl_rcv(struct sock *sk, int len)
112{
113 struct sk_buff *skb;
114
115 while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
116 scsi_nl_rcv_msg(skb);
117 kfree_skb(skb);
118 }
119}
120
121
122/**
123 * scsi_nl_rcv_event -
124 * Event handler for a netlink socket.
125 *
126 * @this: event notifier block
127 * @event: event type
128 * @ptr: event payload
129 *
130 **/
131static int
132scsi_nl_rcv_event(struct notifier_block *this, unsigned long event, void *ptr)
133{
134 struct netlink_notify *n = ptr;
135
136 if (n->protocol != NETLINK_SCSITRANSPORT)
137 return NOTIFY_DONE;
138
139 /*
140 * Currently, we are not tracking PID's, etc. There is nothing
141 * to handle.
142 */
143
144 return NOTIFY_DONE;
145}
146
147static struct notifier_block scsi_netlink_notifier = {
148 .notifier_call = scsi_nl_rcv_event,
149};
150
151
152/**
153 * scsi_netlink_init -
154 * Called by SCSI subsystem to intialize the SCSI transport netlink
155 * interface
156 *
157 **/
158void
159scsi_netlink_init(void)
160{
161 int error;
162
163 error = netlink_register_notifier(&scsi_netlink_notifier);
164 if (error) {
165 printk(KERN_ERR "%s: register of event handler failed - %d\n",
166 __FUNCTION__, error);
167 return;
168 }
169
170 scsi_nl_sock = netlink_kernel_create(NETLINK_SCSITRANSPORT,
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700171 SCSI_NL_GRP_CNT, scsi_nl_rcv, NULL,
172 THIS_MODULE);
James Smart84314fd2006-08-18 17:30:09 -0400173 if (!scsi_nl_sock) {
174 printk(KERN_ERR "%s: register of recieve handler failed\n",
175 __FUNCTION__);
176 netlink_unregister_notifier(&scsi_netlink_notifier);
177 }
178
179 return;
180}
181
182
183/**
184 * scsi_netlink_exit -
185 * Called by SCSI subsystem to disable the SCSI transport netlink
186 * interface
187 *
188 **/
189void
190scsi_netlink_exit(void)
191{
192 if (scsi_nl_sock) {
193 sock_release(scsi_nl_sock->sk_socket);
194 netlink_unregister_notifier(&scsi_netlink_notifier);
195 }
196
197 return;
198}
199
200