1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * scsi_netlink.c - SCSI Transport Netlink Interface
4 *
5 * Copyright (C) 2006 James Smart, Emulex Corporation
6 */
7 #include <linux/time.h>
8 #include <linux/jiffies.h>
9 #include <linux/security.h>
10 #include <linux/delay.h>
11 #include <linux/slab.h>
12 #include <linux/export.h>
13 #include <net/sock.h>
14 #include <net/netlink.h>
15
16 #include <scsi/scsi_netlink.h>
17 #include "scsi_priv.h"
18
19 struct sock *scsi_nl_sock = NULL;
20 EXPORT_SYMBOL_GPL(scsi_nl_sock);
21
22 /**
23 * scsi_nl_rcv_msg - Receive message handler.
24 * @skb: socket receive buffer
25 *
26 * Description: Extracts message from a receive buffer.
27 * Validates message header and calls appropriate transport message handler
28 *
29 *
30 **/
31 static void
scsi_nl_rcv_msg(struct sk_buff * skb)32 scsi_nl_rcv_msg(struct sk_buff *skb)
33 {
34 struct nlmsghdr *nlh;
35 struct scsi_nl_hdr *hdr;
36 u32 rlen;
37 int err, tport;
38
39 while (skb->len >= NLMSG_HDRLEN) {
40 err = 0;
41
42 nlh = nlmsg_hdr(skb);
43 if ((nlh->nlmsg_len < (sizeof(*nlh) + sizeof(*hdr))) ||
44 (skb->len < nlh->nlmsg_len)) {
45 printk(KERN_WARNING "%s: discarding partial skb\n",
46 __func__);
47 return;
48 }
49
50 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
51 if (rlen > skb->len)
52 rlen = skb->len;
53
54 if (nlh->nlmsg_type != SCSI_TRANSPORT_MSG) {
55 err = -EBADMSG;
56 goto next_msg;
57 }
58
59 hdr = nlmsg_data(nlh);
60 if ((hdr->version != SCSI_NL_VERSION) ||
61 (hdr->magic != SCSI_NL_MAGIC)) {
62 err = -EPROTOTYPE;
63 goto next_msg;
64 }
65
66 if (!netlink_capable(skb, CAP_SYS_ADMIN)) {
67 err = -EPERM;
68 goto next_msg;
69 }
70
71 if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
72 printk(KERN_WARNING "%s: discarding partial message\n",
73 __func__);
74 goto next_msg;
75 }
76
77 /*
78 * Deliver message to the appropriate transport
79 */
80 tport = hdr->transport;
81 if (tport == SCSI_NL_TRANSPORT) {
82 switch (hdr->msgtype) {
83 case SCSI_NL_SHOST_VENDOR:
84 /* Locate the driver that corresponds to the message */
85 err = -ESRCH;
86 break;
87 default:
88 err = -EBADR;
89 break;
90 }
91 if (err)
92 printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
93 __func__, hdr->msgtype, err);
94 }
95 else
96 err = -ENOENT;
97
98 next_msg:
99 if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
100 netlink_ack(skb, nlh, err, NULL);
101
102 skb_pull(skb, rlen);
103 }
104 }
105
106 /**
107 * scsi_netlink_init - Called by SCSI subsystem to initialize
108 * the SCSI transport netlink interface
109 *
110 **/
111 void
scsi_netlink_init(void)112 scsi_netlink_init(void)
113 {
114 struct netlink_kernel_cfg cfg = {
115 .input = scsi_nl_rcv_msg,
116 .groups = SCSI_NL_GRP_CNT,
117 };
118
119 scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
120 &cfg);
121 if (!scsi_nl_sock) {
122 printk(KERN_ERR "%s: register of receive handler failed\n",
123 __func__);
124 return;
125 }
126
127 return;
128 }
129
130
131 /**
132 * scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
133 *
134 **/
135 void
scsi_netlink_exit(void)136 scsi_netlink_exit(void)
137 {
138 if (scsi_nl_sock) {
139 netlink_kernel_release(scsi_nl_sock);
140 }
141
142 return;
143 }
144
145