scsi_netlink.c
/*
* 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 <linux/delay.h>
#include <linux/slab.h>
#include <linux/export.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.
* @skb: socket receive buffer
*
* Description: Extracts message from a receive buffer.
* Validates message header and calls appropriate transport message handler
*
*
**/
static void
scsi_nl_rcv_msg(struct sk_buff *skb)
{
struct nlmsghdr *nlh;
struct scsi_nl_hdr *hdr;
u32 rlen;
int err, tport;
while (skb->len >= NLMSG_HDRLEN) {
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",
__func__);
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 (!capable(CAP_SYS_ADMIN)) {
err = -EPERM;
goto next_msg;
}
if (nlh->nlmsg_len < (sizeof(*nlh) + hdr->msglen)) {
printk(KERN_WARNING "%s: discarding partial message\n",
__func__);
goto next_msg;
}
/*
* Deliver message to the appropriate transport
*/
tport = hdr->transport;
if (tport == SCSI_NL_TRANSPORT) {
switch (hdr->msgtype) {
case SCSI_NL_SHOST_VENDOR:
/* Locate the driver that corresponds to the message */
err = -ESRCH;
break;
default:
err = -EBADR;
break;
}
if (err)
printk(KERN_WARNING "%s: Msgtype %d failed - err %d\n",
__func__, hdr->msgtype, err);
}
else
err = -ENOENT;
next_msg:
if ((err) || (nlh->nlmsg_flags & NLM_F_ACK))
netlink_ack(skb, nlh, err);
skb_pull(skb, rlen);
}
}
/**
* scsi_netlink_init - Called by SCSI subsystem to initialize
* the SCSI transport netlink interface
*
**/
void
scsi_netlink_init(void)
{
struct netlink_kernel_cfg cfg = {
.input = scsi_nl_rcv_msg,
.groups = SCSI_NL_GRP_CNT,
};
scsi_nl_sock = netlink_kernel_create(&init_net, NETLINK_SCSITRANSPORT,
&cfg);
if (!scsi_nl_sock) {
printk(KERN_ERR "%s: register of receive handler failed\n",
__func__);
return;
}
return;
}
/**
* scsi_netlink_exit - Called by SCSI subsystem to disable the SCSI transport netlink interface
*
**/
void
scsi_netlink_exit(void)
{
if (scsi_nl_sock) {
netlink_kernel_release(scsi_nl_sock);
}
return;
}