root/security/selinux/netlink.c

DEFINITIONS

1. selnl_msglen
2. selnl_add_payload
3. selnl_notify
4. selnl_notify_setenforce
5. selnl_notify_policyload
6. selnl_init

/*
 * 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/stddef.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/selinux_netlink.h>
#include <net/net_namespace.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 = alloc_skb(NLMSG_SPACE(len), GFP_USER);
        if (!skb)
                goto oom;

        tmp = skb->tail;
        nlh = NLMSG_PUT(skb, 0, 0, msgtype, len);
        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;

nlmsg_failure:
        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)
{
        selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX,
                                      SELNLGRP_MAX, NULL, NULL, THIS_MODULE);
        if (selnl == NULL)
                panic("SELinux:  Cannot create netlink socket.");
        netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV);
        return 0;
}

__initcall(selnl_init);