linux/drivers/scsi/scsi_netlink.c
Eric W. Biederman 8289bab1da scsi_netlink: Remove dead and buggy code
The scsi netlink code confuses the netlink port id with a process id,
going so far as to read NETLINK_CREDS(skb)->pid instead of the correct
NETLINK_CB(skb).pid.  Fortunately it does not matter because nothing
registers to respond to scsi netlink requests.

The only interesting use of the scsi_netlink interface is
fc_host_post_vendor_event which sends a netlink multicast message.

Since nothing registers to handle scsi netlink messages kill all of the
registration logic, while retaining the same error handling behavior
preserving the userspace visible behavior and removing all of the
confused code that thought a netlink port id was a process id.

This was tested with a kernel allyesconfig build which had no problems.

Cc: James Bottomley <James.Bottomley@parallels.com>
Cc: James Smart <James.Smart@Emulex.Com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-13 16:26:39 -04:00

159 lines
3.5 KiB
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_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",
__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;
}