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 21 static struct sock *selnl; 22 23 static 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 42 static 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 66 static 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_CB(skb).dst_group = SELNLGRP_AVC; 84 netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER); 85 out: 86 return; 87 88 nlmsg_failure: 89 kfree_skb(skb); 90 oom: 91 printk(KERN_ERR "SELinux: OOM in %s\n", __FUNCTION__); 92 goto out; 93 } 94 95 void selnl_notify_setenforce(int val) 96 { 97 selnl_notify(SELNL_MSG_SETENFORCE, &val); 98 } 99 100 void selnl_notify_policyload(u32 seqno) 101 { 102 selnl_notify(SELNL_MSG_POLICYLOAD, &seqno); 103 } 104 105 static int __init selnl_init(void) 106 { 107 selnl = netlink_kernel_create(NETLINK_SELINUX, NULL, THIS_MODULE); 108 if (selnl == NULL) 109 panic("SELinux: Cannot create netlink socket."); 110 netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV); 111 return 0; 112 } 113 114 __initcall(selnl_init); 115