LXR linux-bk/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
  21static struct sock *selnl;
  22
  23static int selnl_msglen(int msgtype)
  24{
  25        int ret = 0;
  26        
  27        switch (msgtype) {
  28        case SELNL_MSG_SETENFORCE:
  29                ret = sizeof(struct selnl_msg_setenforce);
  30                break;
  31        
  32        case SELNL_MSG_POLICYLOAD:
  33                ret = sizeof(struct selnl_msg_policyload);
  34                break;
  35                
  36        default:
  37                BUG();
  38        }
  39        return ret;
  40}
  41
  42static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data)
  43{
  44        switch (msgtype) {
  45        case SELNL_MSG_SETENFORCE: {
  46                struct selnl_msg_setenforce *msg = NLMSG_DATA(nlh);
  47                
  48                memset(msg, 0, len);
  49                msg->val = *((int *)data);
  50                break;
  51        }
  52        
  53        case SELNL_MSG_POLICYLOAD: {
  54                struct selnl_msg_policyload *msg = NLMSG_DATA(nlh);
  55                
  56                memset(msg, 0, len);
  57                msg->seqno = *((u32 *)data);
  58                break;
  59        }
  60
  61        default:
  62                BUG();
  63        }
  64}
  65
  66static void selnl_notify(int msgtype, void *data)
  67{
  68        int len;
  69        unsigned char *tmp;
  70        struct sk_buff *skb;
  71        struct nlmsghdr *nlh;
  72        
  73        len = selnl_msglen(msgtype);
  74        
  75        skb = alloc_skb(NLMSG_SPACE(len), GFP_USER);
  76        if (!skb)
  77                goto oom;
  78
  79        tmp = skb->tail;
  80        nlh = NLMSG_PUT(skb, 0, 0, msgtype, len);
  81        selnl_add_payload(nlh, len, msgtype, data);
  82        nlh->nlmsg_len = skb->tail - tmp;
  83        netlink_broadcast(selnl, skb, 0, SELNL_GRP_AVC, GFP_USER);
  84out:
  85        return;
  86        
  87nlmsg_failure:
  88        kfree_skb(skb);
  89oom:
  90        printk(KERN_ERR "SELinux:  OOM in %s\n", __FUNCTION__);
  91        goto out;
  92}
  93
  94void selnl_notify_setenforce(int val)
  95{
  96        selnl_notify(SELNL_MSG_SETENFORCE, &val);
  97}
  98
  99void selnl_notify_policyload(u32 seqno)
 100{
 101        selnl_notify(SELNL_MSG_POLICYLOAD, &seqno);
 102}
 103
 104static int __init selnl_init(void)
 105{
 106        selnl = netlink_kernel_create(NETLINK_SELINUX, NULL);
 107        if (selnl == NULL)
 108                panic("SELinux:  Cannot create netlink socket.");
 109        netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV);  
 110        return 0;
 111}
 112
 113__initcall(selnl_init);
 114