/*
* 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 = nlmsg_hdr(skb);
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;
}
