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/slab.h> 15 #include <linux/stddef.h> 16 #include <linux/kernel.h> 17 #include <linux/skbuff.h> 18 #include <linux/netlink.h> 19 #include <linux/selinux_netlink.h> 20 #include <net/net_namespace.h> 21 22 #include "security.h" 23 24 static struct sock *selnl; 25 26 static int selnl_msglen(int msgtype) 27 { 28 int ret = 0; 29 30 switch (msgtype) { 31 case SELNL_MSG_SETENFORCE: 32 ret = sizeof(struct selnl_msg_setenforce); 33 break; 34 35 case SELNL_MSG_POLICYLOAD: 36 ret = sizeof(struct selnl_msg_policyload); 37 break; 38 39 default: 40 BUG(); 41 } 42 return ret; 43 } 44 45 static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data) 46 { 47 switch (msgtype) { 48 case SELNL_MSG_SETENFORCE: { 49 struct selnl_msg_setenforce *msg = NLMSG_DATA(nlh); 50 51 memset(msg, 0, len); 52 msg->val = *((int *)data); 53 break; 54 } 55 56 case SELNL_MSG_POLICYLOAD: { 57 struct selnl_msg_policyload *msg = NLMSG_DATA(nlh); 58 59 memset(msg, 0, len); 60 msg->seqno = *((u32 *)data); 61 break; 62 } 63 64 default: 65 BUG(); 66 } 67 } 68 69 static void selnl_notify(int msgtype, void *data) 70 { 71 int len; 72 sk_buff_data_t tmp; 73 struct sk_buff *skb; 74 struct nlmsghdr *nlh; 75 76 len = selnl_msglen(msgtype); 77 78 skb = alloc_skb(NLMSG_SPACE(len), GFP_USER); 79 if (!skb) 80 goto oom; 81 82 tmp = skb->tail; 83 nlh = NLMSG_PUT(skb, 0, 0, msgtype, len); 84 selnl_add_payload(nlh, len, msgtype, data); 85 nlh->nlmsg_len = skb->tail - tmp; 86 NETLINK_CB(skb).dst_group = SELNLGRP_AVC; 87 netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER); 88 out: 89 return; 90 91 nlmsg_failure: 92 kfree_skb(skb); 93 oom: 94 printk(KERN_ERR "SELinux: OOM in %s\n", __func__); 95 goto out; 96 } 97 98 void selnl_notify_setenforce(int val) 99 { 100 selnl_notify(SELNL_MSG_SETENFORCE, &val); 101 } 102 103 void selnl_notify_policyload(u32 seqno) 104 { 105 selnl_notify(SELNL_MSG_POLICYLOAD, &seqno); 106 } 107 108 static int __init selnl_init(void) 109 { 110 selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, 111 SELNLGRP_MAX, NULL, NULL, THIS_MODULE); 112 if (selnl == NULL) 113 panic("SELinux: Cannot create netlink socket."); 114 netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV); 115 return 0; 116 } 117 118 __initcall(selnl_init); 119