LXR linux/security/selinux/netlink.c

   1/*
   2 * Netlink event notifications for SELinux.
   3 *
   4 * Author: James Morris <jmorris@redhat.com>
   5 *
   6 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2,
  10 * as published by the Free Software Foundation.
  11 */
  12#include <linux/init.h>
  13#include <linux/types.h>
  14#include <linux/stddef.h>
  15#include <linux/kernel.h>
  16#include <linux/list.h>
  17#include <linux/skbuff.h>
  18#include <linux/netlink.h>
  19#include <linux/selinux_netlink.h>
  20#include <net/net_namespace.h>
  21
  22static struct sock *selnl;
  23
  24static int selnl_msglen(int msgtype)
  25{
  26        int ret = 0;
  27
  28        switch (msgtype) {
  29        case SELNL_MSG_SETENFORCE:
  30                ret = sizeof(struct selnl_msg_setenforce);
  31                break;
  32
  33        case SELNL_MSG_POLICYLOAD:
  34                ret = sizeof(struct selnl_msg_policyload);
  35                break;
  36
  37        default:
  38                BUG();
  39        }
  40        return ret;
  41}
  42
  43static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data)
  44{
  45        switch (msgtype) {
  46        case SELNL_MSG_SETENFORCE: {
  47                struct selnl_msg_setenforce *msg = NLMSG_DATA(nlh);
  48
  49                memset(msg, 0, len);
  50                msg->val = *((int *)data);
  51                break;
  52        }
  53
  54        case SELNL_MSG_POLICYLOAD: {
  55                struct selnl_msg_policyload *msg = NLMSG_DATA(nlh);
  56
  57                memset(msg, 0, len);
  58                msg->seqno = *((u32 *)data);
  59                break;
  60        }
  61
  62        default:
  63                BUG();
  64        }
  65}
  66
  67static void selnl_notify(int msgtype, void *data)
  68{
  69        int len;
  70        sk_buff_data_t tmp;
  71        struct sk_buff *skb;
  72        struct nlmsghdr *nlh;
  73
  74        len = selnl_msglen(msgtype);
  75
  76        skb = alloc_skb(NLMSG_SPACE(len), GFP_USER);
  77        if (!skb)
  78                goto oom;
  79
  80        tmp = skb->tail;
  81        nlh = NLMSG_PUT(skb, 0, 0, msgtype, len);
  82        selnl_add_payload(nlh, len, msgtype, data);
  83        nlh->nlmsg_len = skb->tail - tmp;
  84        NETLINK_CB(skb).dst_group = SELNLGRP_AVC;
  85        netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER);
  86out:
  87        return;
  88
  89nlmsg_failure:
  90        kfree_skb(skb);
  91oom:
  92        printk(KERN_ERR "SELinux:  OOM in %s\n", __func__);
  93        goto out;
  94}
  95
  96void selnl_notify_setenforce(int val)
  97{
  98        selnl_notify(SELNL_MSG_SETENFORCE, &val);
  99}
 100
 101void selnl_notify_policyload(u32 seqno)
 102{
 103        selnl_notify(SELNL_MSG_POLICYLOAD, &seqno);
 104}
 105
 106static int __init selnl_init(void)
 107{
 108        selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX,
 109                                      SELNLGRP_MAX, NULL, NULL, THIS_MODULE);
 110        if (selnl == NULL)
 111                panic("SELinux:  Cannot create netlink socket.");
 112        netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV);
 113        return 0;
 114}
 115
 116__initcall(selnl_init);
 117