1/*
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 <linux/delay.h>
25#include <linux/slab.h>
26#include <linux/export.h>
27#include <net/sock.h>
28#include <net/netlink.h>
29
30#include <scsi/scsi_netlink.h>
31#include "scsi_priv.h"
32
33struct sock *scsi_nl_sock = NULL;
34EXPORT_SYMBOL_GPL(scsi_nl_sock);
35
36/**
37 * scsi_nl_rcv_msg - Receive message handler.
38 * @skb: socket receive buffer
39 *
40 * Description: Extracts message from a receive buffer.
41 * Validates message header and calls appropriate transport message handler
42 *
43 *
44 **/
45static void
46scsi_nl_rcv_msg(struct sk_buff *skb)
47{
48 struct nlmsghdr *nlh;
49 struct scsi_nl_hdr *hdr;
50 u32 rlen;
51 int err, tport;
52
53 while (skb->len >= NLMSG_HDRLEN) {
54 err = 0;
55
56 nlh = nlmsg_hdr(skb);
57 if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) ||
58 (skb->len < nlh->nlmsg_len)) {
59 printk(KERN_WARNING "%s: discarding partial skb\n",
60 __func__);
61 return;
62 }
63
64 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
65 if (rlen > skb->len)
66 rlen = skb->len;
67
68 if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
69 err = -EBADMSG;
70 goto next_msg;
71 }
72
73 hdr = nlmsg_data(nlh);
74 if ((hdr->version != SCSI_NL_VERSION) ||
75 (hdr->magic != SCSI_NL_MAGIC)) {
76 err = -EPROTOTYPE;
77 goto next_msg;
78 }
79
80 if (!netlink_capable(skb, CAP_SYS_ADMIN)) {
81 err = -EPERM;
82 goto next_msg;
83 }
84
85 if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
86 printk(KERN_WARNING "%s: discarding partial message\n",
87 __func__);
88 goto next_msg;
89 }
90
91 /*
92 * Deliver message to the appropriate transport
93 */
94 tport = hdr->transport;
95 if (tport == SCSI_NL_TRANSPORT) {
96 switch (hdr->msgtype) {
97 case SCSI_NL_SHOST_VENDOR:
98 /* Locate the driver that corresponds to the message */
99 err = -ESRCH;
100 break;
101 default:
102 err = -EBADR;
103 break;
104 }
105 if (err)
106 printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
107 __func__, hdr->msgtype, err);
108 }
109 else
110 err = -ENOENT;
111
112next_msg:
113 if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
114 netlink_ack(skb, nlh, err, NULL);
115
116 skb_pull(skb, rlen);
117 }
118}
119
120/**
121 * scsi_netlink_init - Called by SCSI subsystem to initialize
122 * the SCSI transport netlink interface
123 *
124 **/
125void
126scsi_netlink_init(void)
127{
128 struct netlink_kernel_cfg cfg = {
129 .input = scsi_nl_rcv_msg,
130 .groups = SCSI_NL_GRP_CNT,
131 };
132
133 scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
134 &cfg);
135 if (!scsi_nl_sock) {
136 printk(KERN_ERR "%s: register of receive handler failed\n",
137 __func__);
138 return;
139 }
140
141 return;
142}
143
144
145/**
146 * scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
147 *
148 **/
149void
150scsi_netlink_exit(void)
151{
152 if (scsi_nl_sock) {
153 netlink_kernel_release(scsi_nl_sock);
154 }
155
156 return;
157}
158
159