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/export.h> 18 #include <linux/skbuff.h> 19 #include <linux/netlink.h> 20 #include <linux/selinux_netlink.h> 21 #include <net/net_namespace.h> 22 #include <net/netlink.h> 23 24 #include "security.h" 25 26 static struct sock *selnl; 27 28 static int selnl_msglen(int msgtype) 29 { 30 int ret = 0; 31 32 switch (msgtype) { 33 case SELNL_MSG_SETENFORCE: 34 ret = sizeof(struct selnl_msg_setenforce); 35 break; 36 37 case SELNL_MSG_POLICYLOAD: 38 ret = sizeof(struct selnl_msg_policyload); 39 break; 40 41 default: 42 BUG(); 43 } 44 return ret; 45 } 46 47 static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data) 48 { 49 switch (msgtype) { 50 case SELNL_MSG_SETENFORCE: { 51 struct selnl_msg_setenforce *msg = nlmsg_data(nlh); 52 53 memset(msg, 0, len); 54 msg->val = *((int *)data); 55 break; 56 } 57 58 case SELNL_MSG_POLICYLOAD: { 59 struct selnl_msg_policyload *msg = nlmsg_data(nlh); 60 61 memset(msg, 0, len); 62 msg->seqno = *((u32 *)data); 63 break; 64 } 65 66 default: 67 BUG(); 68 } 69 } 70 71 static void selnl_notify(int msgtype, void *data) 72 { 73 int len; 74 sk_buff_data_t tmp; 75 struct sk_buff *skb; 76 struct nlmsghdr *nlh; 77 78 len = selnl_msglen(msgtype); 79 80 skb = alloc_skb(NLMSG_SPACE(len), GFP_USER); 81 if (!skb) 82 goto oom; 83 84 tmp = skb->tail; 85 nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0); 86 if (!nlh) 87 goto out_kfree_skb; 88 selnl_add_payload(nlh, len, msgtype, data); 89 nlh->nlmsg_len = skb->tail - tmp; 90 NETLINK_CB(skb).dst_group = SELNLGRP_AVC; 91 netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER); 92 out: 93 return; 94 95 out_kfree_skb: 96 kfree_skb(skb); 97 oom: 98 printk(KERN_ERR "SELinux: OOM in %s\n", __func__); 99 goto out; 100 } 101 102 void selnl_notify_setenforce(int val) 103 { 104 selnl_notify(SELNL_MSG_SETENFORCE, &val); 105 } 106 107 void selnl_notify_policyload(u32 seqno) 108 { 109 selnl_notify(SELNL_MSG_POLICYLOAD, &seqno); 110 } 111 112 static int __init selnl_init(void) 113 { 114 struct netlink_kernel_cfg cfg = { 115 .groups = SELNLGRP_MAX, 116 }; 117 118 selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, 119 THIS_MODULE, &cfg); 120 if (selnl == NULL) 121 panic("SELinux: Cannot create netlink socket."); 122 netlink_set_nonroot(NETLINK_SELINUX, NL_NONROOT_RECV); 123 return 0; 124 } 125 126 __initcall(selnl_init); 127