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