1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Netlink event notifications for SELinux. 4 * 5 * Author: James Morris <jmorris@redhat.com> 6 * 7 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> 8 */ 9 #include <linux/init.h> 10 #include <linux/types.h> 11 #include <linux/slab.h> 12 #include <linux/stddef.h> 13 #include <linux/kernel.h> 14 #include <linux/export.h> 15 #include <linux/skbuff.h> 16 #include <linux/selinux_netlink.h> 17 #include <net/net_namespace.h> 18 #include <net/netlink.h> 19 20 #include "security.h" 21 22 static struct sock *selnl __ro_after_init; 23 24 static int selnl_msglen(int msgtype) 25 { 26 int ret = 0; 27 28 switch (msgtype) { 29 case SELNL_MSG_SETENFORCE: 30 ret = sizeof(struct selnl_msg_setenforce); 31 break; 32 33 case SELNL_MSG_POLICYLOAD: 34 ret = sizeof(struct selnl_msg_policyload); 35 break; 36 37 default: 38 BUG(); 39 } 40 return ret; 41 } 42 43 static void selnl_add_payload(struct nlmsghdr *nlh, int len, int msgtype, void *data) 44 { 45 switch (msgtype) { 46 case SELNL_MSG_SETENFORCE: { 47 struct selnl_msg_setenforce *msg = nlmsg_data(nlh); 48 49 memset(msg, 0, len); 50 msg->val = *((int *)data); 51 break; 52 } 53 54 case SELNL_MSG_POLICYLOAD: { 55 struct selnl_msg_policyload *msg = nlmsg_data(nlh); 56 57 memset(msg, 0, len); 58 msg->seqno = *((u32 *)data); 59 break; 60 } 61 62 default: 63 BUG(); 64 } 65 } 66 67 static void selnl_notify(int msgtype, void *data) 68 { 69 int len; 70 sk_buff_data_t tmp; 71 struct sk_buff *skb; 72 struct nlmsghdr *nlh; 73 74 len = selnl_msglen(msgtype); 75 76 skb = nlmsg_new(len, GFP_USER); 77 if (!skb) 78 goto oom; 79 80 tmp = skb->tail; 81 nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0); 82 if (!nlh) 83 goto out_kfree_skb; 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 out_kfree_skb: 92 kfree_skb(skb); 93 oom: 94 pr_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 struct netlink_kernel_cfg cfg = { 111 .groups = SELNLGRP_MAX, 112 .flags = NL_CFG_F_NONROOT_RECV, 113 }; 114 115 selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg); 116 if (selnl == NULL) 117 panic("SELinux: Cannot create netlink socket."); 118 return 0; 119 } 120 121 __initcall(selnl_init); 122