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 "initcalls.h" 21 #include "security.h" 22 23 static struct sock *selnl __ro_after_init; 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 = nlmsg_new(len, GFP_USER); 78 if (!skb) 79 goto oom; 80 81 tmp = skb->tail; 82 nlh = nlmsg_put(skb, 0, 0, msgtype, len, 0); 83 if (!nlh) 84 goto out_kfree_skb; 85 selnl_add_payload(nlh, len, msgtype, data); 86 nlh->nlmsg_len = skb->tail - tmp; 87 NETLINK_CB(skb).dst_group = SELNLGRP_AVC; 88 netlink_broadcast(selnl, skb, 0, SELNLGRP_AVC, GFP_USER); 89 out: 90 return; 91 92 out_kfree_skb: 93 kfree_skb(skb); 94 oom: 95 pr_err("SELinux: OOM in %s\n", __func__); 96 goto out; 97 } 98 99 void selnl_notify_setenforce(int val) 100 { 101 selnl_notify(SELNL_MSG_SETENFORCE, &val); 102 } 103 104 void selnl_notify_policyload(u32 seqno) 105 { 106 selnl_notify(SELNL_MSG_POLICYLOAD, &seqno); 107 } 108 109 int __init sel_netlink_init(void) 110 { 111 struct netlink_kernel_cfg cfg = { 112 .groups = SELNLGRP_MAX, 113 .flags = NL_CFG_F_NONROOT_RECV, 114 }; 115 116 selnl = netlink_kernel_create(&init_net, NETLINK_SELINUX, &cfg); 117 if (selnl == NULL) 118 panic("SELinux: Cannot create netlink socket."); 119 return 0; 120 } 121