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84314fd4 JS |
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 <net/sock.h> | |
25 | #include <net/netlink.h> | |
26 | ||
27 | #include <scsi/scsi_netlink.h> | |
28 | #include "scsi_priv.h" | |
29 | ||
30 | struct sock *scsi_nl_sock = NULL; | |
31 | EXPORT_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 | **/ | |
42 | static void | |
43 | scsi_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 | ||
b529ccf2 | 53 | nlh = nlmsg_hdr(skb); |
84314fd4 JS |
54 | 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 | ||
92 | next_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 | **/ | |
110 | static void | |
111 | scsi_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 | **/ | |
131 | static int | |
132 | scsi_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 | ||
147 | static 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 | **/ | |
158 | void | |
159 | scsi_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 | ||
b4b51029 | 170 | scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT, |
af65bdfc PM |
171 | SCSI_NL_GRP_CNT, scsi_nl_rcv, NULL, |
172 | THIS_MODULE); | |
84314fd4 JS |
173 | 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 | **/ | |
189 | void | |
190 | scsi_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 |