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