linux-stable/drivers/scsi/scsi_netlink.c
Johannes Berg 2d4bc93368 netlink: extended ACK reporting
Add the base infrastructure and UAPI for netlink extended ACK
reporting. All "manual" calls to netlink_ack() pass NULL for now and
thus don't get extended ACK reporting.

Big thanks goes to Pablo Neira Ayuso for not only bringing up the
whole topic at netconf (again) but also coming up with the nlattr
passing trick and various other ideas.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:20 -04:00

158 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_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 (!netlink_capable(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",
__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, NULL);
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;
}