netlink.c
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/*
* Netlink event notifications for SELinux.
*
* Author: James Morris <jmorris@redhat.com>
*
* Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2,
* as published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/skbuff.h>
#include <linux/selinux_netlink.h>
#include <net/net_namespace.h>
#include <net/netlink.h>
#include "security.h"
static struct sock *selnl;
static int selnl_msglen(int msgtype)
{
int ret = 0;
switch (msgtype) {
case SELNL_MSG_SETENFORCE:
ret = sizeof(struct selnl_msg_setenforce);
break;
case SELNL_MSG_POLICYLOAD:
ret = sizeof(struct selnl_msg_policyload);
break;
default:
BUG();
}
return ret;
}
static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data)
{
switch (msgtype) {
case SELNL_MSG_SETENFORCE: {
struct selnl_msg_setenforce *msg = nlmsg_data(nlh);
memset(msg, 0, len);
msg->val = *((int *)data);
break;
}
case SELNL_MSG_POLICYLOAD: {
struct selnl_msg_policyload *msg = nlmsg_data(nlh);
memset(msg, 0, len);
msg->seqno = *((u32 *)data);
break;
}
default:
BUG();
}
}
static void selnl_notify(int msgtype, void *data)
{
int len;
sk_buff_data_t tmp;
struct sk_buff *skb;
struct nlmsghdr *nlh;
len = selnl_msglen(msgtype);
skb = nlmsg_new(len, GFP_USER);
if (!skb)
goto oom;
tmp = skb->tail;
nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0);
if (!nlh)
goto out_kfree_skb;
selnl_add_payload(nlh, len, msgtype, data);
nlh->nlmsg_len = skb->tail - tmp;
NETLINK_CB(skb).dst_group = SELNLGRP_AVC;
netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER);
out:
return;
out_kfree_skb:
kfree_skb(skb);
oom:
printk(KERN_ERR "SELinux: OOM in %s\n", __func__);
goto out;
}
void selnl_notify_setenforce(int val)
{
selnl_notify(SELNL_MSG_SETENFORCE, &val);
}
void selnl_notify_policyload(u32 seqno)
{
selnl_notify(SELNL_MSG_POLICYLOAD, &seqno);
}
static int __init selnl_init(void)
{
struct netlink_kernel_cfg cfg = {
.groups = SELNLGRP_MAX,
.flags = NL_CFG_F_NONROOT_RECV,
};
selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg);
if (selnl == NULL)
panic("SELinux: Cannot create netlink socket.");
return 0;
}
__initcall(selnl_init);