Smack: IPv6 host labeling

IPv6 appears to be (finally) coming of age with the
influx of autonomous devices. In support of this, add
the ability to associate a Smack label with IPv6 addresses.

This patch also cleans up some of the conditional
compilation associated with the introduction of
secmark processing. It's now more obvious which bit
of code goes with which feature.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

3 files changed, 578 insertions, 160 deletions

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 69ab9eb7d6d9..fff0c612bbb7 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -17,12 +17,27 @@
 #include <linux/spinlock.h>
 #include <linux/lsm_hooks.h>
 #include <linux/in.h>
+#if IS_ENABLED(CONFIG_IPV6)
+#include <linux/in6.h>
+#endif /* CONFIG_IPV6 */
 #include <net/netlabel.h>
 #include <linux/list.h>
 #include <linux/rculist.h>
 #include <linux/lsm_audit.h>
 
 /*
+ * Use IPv6 port labeling if IPv6 is enabled and secmarks
+ * are not being used.
+ */
+#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#define SMACK_IPV6_PORT_LABELING 1
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#define SMACK_IPV6_SECMARK_LABELING 1
+#endif
+
+/*
  * Smack labels were limited to 23 characters for a long time.
  */
 #define SMK_LABELLEN	24
@@ -118,15 +133,30 @@ struct smack_rule {
 };
 
 /*
- * An entry in the table identifying hosts.
+ * An entry in the table identifying IPv4 hosts.
  */
-struct smk_netlbladdr {
+struct smk_net4addr {
 	struct list_head	list;
-	struct sockaddr_in	smk_host;	/* network address */
+	struct in_addr		smk_host;	/* network address */
 	struct in_addr		smk_mask;	/* network mask */
+	int			smk_masks;	/* mask size */
+	struct smack_known	*smk_label;	/* label */
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+/*
+ * An entry in the table identifying IPv6 hosts.
+ */
+struct smk_net6addr {
+	struct list_head	list;
+	struct in6_addr		smk_host;	/* network address */
+	struct in6_addr		smk_mask;	/* network mask */
+	int			smk_masks;	/* mask size */
 	struct smack_known	*smk_label;	/* label */
 };
+#endif /* CONFIG_IPV6 */
 
+#ifdef SMACK_IPV6_PORT_LABELING
 /*
  * An entry in the table identifying ports.
  */
@@ -137,6 +167,7 @@ struct smk_port_label {
 	struct smack_known	*smk_in;	/* inbound label */
 	struct smack_known	*smk_out;	/* outgoing label */
 };
+#endif /* SMACK_IPV6_PORT_LABELING */
 
 struct smack_onlycap {
 	struct list_head	list;
@@ -170,6 +201,7 @@ enum {
 #define SMK_FSROOT	"smackfsroot="
 #define SMK_FSTRANS	"smackfstransmute="
 
+#define SMACK_DELETE_OPTION	"-DELETE"
 #define SMACK_CIPSO_OPTION 	"-CIPSO"
 
 /*
@@ -252,10 +284,6 @@ struct smk_audit_info {
 	struct smack_audit_data sad;
 #endif
 };
-/*
- * These functions are in smack_lsm.c
- */
-struct inode_smack *new_inode_smack(struct smack_known *);
 
 /*
  * These functions are in smack_access.c
@@ -285,7 +313,6 @@ extern struct smack_known *smack_syslog_label;
 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
 extern struct smack_known *smack_unconfined;
 #endif
-extern struct smack_known smack_cipso_option;
 extern int smack_ptrace_rule;
 
 extern struct smack_known smack_known_floor;
@@ -297,7 +324,10 @@ extern struct smack_known smack_known_web;
 
 extern struct mutex	smack_known_lock;
 extern struct list_head smack_known_list;
-extern struct list_head smk_netlbladdr_list;
+extern struct list_head smk_net4addr_list;
+#if IS_ENABLED(CONFIG_IPV6)
+extern struct list_head smk_net6addr_list;
+#endif /* CONFIG_IPV6 */
 
 extern struct mutex     smack_onlycap_lock;
 extern struct list_head smack_onlycap_list;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index d962f887d3f4..cc390bccecd7 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -51,9 +51,9 @@
 #define SMK_RECEIVING	1
 #define SMK_SENDING	2
 
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#ifdef SMACK_IPV6_PORT_LABELING
 LIST_HEAD(smk_ipv6_port_list);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
 static struct kmem_cache *smack_inode_cache;
 int smack_enabled;
 
@@ -2272,7 +2272,7 @@ static void smack_sk_free_security(struct sock *sk)
 }
 
 /**
-* smack_host_label - check host based restrictions
+* smack_ipv4host_label - check host based restrictions
 * @sip: the object end
 *
 * looks for host based access restrictions
@@ -2283,30 +2283,96 @@ static void smack_sk_free_security(struct sock *sk)
 *
 * Returns the label of the far end or NULL if it's not special.
 */
-static struct smack_known *smack_host_label(struct sockaddr_in *sip)
+static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
 {
-	struct smk_netlbladdr *snp;
+	struct smk_net4addr *snp;
 	struct in_addr *siap = &sip->sin_addr;
 
 	if (siap->s_addr == 0)
 		return NULL;
 
-	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
+	list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
+		/*
+		 * we break after finding the first match because
+		 * the list is sorted from longest to shortest mask
+		 * so we have found the most specific match
+		 */
+		if (snp->smk_host.s_addr ==
+		    (siap->s_addr & snp->smk_mask.s_addr))
+			return snp->smk_label;
+
+	return NULL;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/*
+ * smk_ipv6_localhost - Check for local ipv6 host address
+ * @sip: the address
+ *
+ * Returns boolean true if this is the localhost address
+ */
+static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
+{
+	__be16 *be16p = (__be16 *)&sip->sin6_addr;
+	__be32 *be32p = (__be32 *)&sip->sin6_addr;
+
+	if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
+	    ntohs(be16p[7]) == 1)
+		return true;
+	return false;
+}
+
+/**
+* smack_ipv6host_label - check host based restrictions
+* @sip: the object end
+*
+* looks for host based access restrictions
+*
+* This version will only be appropriate for really small sets of single label
+* hosts.  The caller is responsible for ensuring that the RCU read lock is
+* taken before calling this function.
+*
+* Returns the label of the far end or NULL if it's not special.
+*/
+static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
+{
+	struct smk_net6addr *snp;
+	struct in6_addr *sap = &sip->sin6_addr;
+	int i;
+	int found = 0;
+
+	/*
+	 * It's local. Don't look for a host label.
+	 */
+	if (smk_ipv6_localhost(sip))
+		return NULL;
+
+	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
 		/*
 		* we break after finding the first match because
 		* the list is sorted from longest to shortest mask
 		* so we have found the most specific match
 		*/
-		if ((&snp->smk_host.sin_addr)->s_addr ==
-		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
-			/* we have found the special CIPSO option */
-			if (snp->smk_label == &smack_cipso_option)
-				return NULL;
-			return snp->smk_label;
+		for (found = 1, i = 0; i < 8; i++) {
+			/*
+			 * If the label is NULL the entry has
+			 * been renounced. Ignore it.
+			 */
+			if (snp->smk_label == NULL)
+				continue;
+			if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
+			    snp->smk_host.s6_addr16[i]) {
+				found = 0;
+				break;
+			}
 		}
+		if (found)
+			return snp->smk_label;
+	}
 
 	return NULL;
 }
+#endif /* CONFIG_IPV6 */
 
 /**
  * smack_netlabel - Set the secattr on a socket
@@ -2370,7 +2436,7 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
 	struct smk_audit_info ad;
 
 	rcu_read_lock();
-	hkp = smack_host_label(sap);
+	hkp = smack_ipv4host_label(sap);
 	if (hkp != NULL) {
 #ifdef CONFIG_AUDIT
 		struct lsm_network_audit net;
@@ -2395,7 +2461,42 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
 	return smack_netlabel(sk, sk_lbl);
 }
 
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#if IS_ENABLED(CONFIG_IPV6)
+/**
+ * smk_ipv6_check - check Smack access
+ * @subject: subject Smack label
+ * @object: object Smack label
+ * @address: address
+ * @act: the action being taken
+ *
+ * Check an IPv6 access
+ */
+static int smk_ipv6_check(struct smack_known *subject,
+				struct smack_known *object,
+				struct sockaddr_in6 *address, int act)
+{
+#ifdef CONFIG_AUDIT
+	struct lsm_network_audit net;
+#endif
+	struct smk_audit_info ad;
+	int rc;
+
+#ifdef CONFIG_AUDIT
+	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
+	ad.a.u.net->family = PF_INET6;
+	ad.a.u.net->dport = ntohs(address->sin6_port);
+	if (act == SMK_RECEIVING)
+		ad.a.u.net->v6info.saddr = address->sin6_addr;
+	else
+		ad.a.u.net->v6info.daddr = address->sin6_addr;
+#endif
+	rc = smk_access(subject, object, MAY_WRITE, &ad);
+	rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
+	return rc;
+}
+#endif /* CONFIG_IPV6 */
+
+#ifdef SMACK_IPV6_PORT_LABELING
 /**
  * smk_ipv6_port_label - Smack port access table management
  * @sock: socket
@@ -2479,48 +2580,43 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
 				int act)
 {
-	__be16 *bep;
-	__be32 *be32p;
 	struct smk_port_label *spp;
 	struct socket_smack *ssp = sk->sk_security;
-	struct smack_known *skp;
-	unsigned short port = 0;
+	struct smack_known *skp = NULL;
+	unsigned short port;
 	struct smack_known *object;
-	struct smk_audit_info ad;
-	int rc;
-#ifdef CONFIG_AUDIT
-	struct lsm_network_audit net;
-#endif
 
 	if (act == SMK_RECEIVING) {
-		skp = smack_net_ambient;
+		skp = smack_ipv6host_label(address);
 		object = ssp->smk_in;
 	} else {
 		skp = ssp->smk_out;
-		object = smack_net_ambient;
+		object = smack_ipv6host_label(address);
 	}
 
 	/*
-	 * Get the IP address and port from the address.
+	 * The other end is a single label host.
 	 */
-	port = ntohs(address->sin6_port);
-	bep = (__be16 *)(&address->sin6_addr);
-	be32p = (__be32 *)(&address->sin6_addr);
+	if (skp != NULL && object != NULL)
+		return smk_ipv6_check(skp, object, address, act);
+	if (skp == NULL)
+		skp = smack_net_ambient;
+	if (object == NULL)
+		object = smack_net_ambient;
 
 	/*
 	 * It's remote, so port lookup does no good.
 	 */
-	if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
-		goto auditout;
+	if (!smk_ipv6_localhost(address))
+		return smk_ipv6_check(skp, object, address, act);
 
 	/*
 	 * It's local so the send check has to have passed.
 	 */
-	if (act == SMK_RECEIVING) {
-		skp = &smack_known_web;
-		goto auditout;
-	}
+	if (act == SMK_RECEIVING)
+		return 0;
 
+	port = ntohs(address->sin6_port);
 	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
 		if (spp->smk_port != port)
 			continue;
@@ -2530,22 +2626,9 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
 		break;
 	}
 
-auditout:
-
-#ifdef CONFIG_AUDIT
-	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
-	ad.a.u.net->family = sk->sk_family;
-	ad.a.u.net->dport = port;
-	if (act == SMK_RECEIVING)
-		ad.a.u.net->v6info.saddr = address->sin6_addr;
-	else
-		ad.a.u.net->v6info.daddr = address->sin6_addr;
-#endif
-	rc = smk_access(skp, object, MAY_WRITE, &ad);
-	rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc);
-	return rc;
+	return smk_ipv6_check(skp, object, address, act);
 }
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_PORT_LABELING */
 
 /**
  * smack_inode_setsecurity - set smack xattrs
@@ -2606,10 +2689,10 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
 	} else
 		return -EOPNOTSUPP;
 
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#ifdef SMACK_IPV6_PORT_LABELING
 	if (sock->sk->sk_family == PF_INET6)
 		smk_ipv6_port_label(sock, NULL);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
 
 	return 0;
 }
@@ -2651,7 +2734,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
 	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
 }
 
-#ifndef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_PORT_LABELING
 /**
  * smack_socket_bind - record port binding information.
  * @sock: the socket
@@ -2665,14 +2748,11 @@ static int smack_socket_post_create(struct socket *sock, int family,
 static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
 				int addrlen)
 {
-#if IS_ENABLED(CONFIG_IPV6)
 	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
 		smk_ipv6_port_label(sock, address);
-#endif
-
 	return 0;
 }
-#endif /* !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_PORT_LABELING */
 
 /**
  * smack_socket_connect - connect access check
@@ -2688,6 +2768,13 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
 				int addrlen)
 {
 	int rc = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
+#endif
+#ifdef SMACK_IPV6_SECMARK_LABELING
+	struct smack_known *rsp;
+	struct socket_smack *ssp = sock->sk->sk_security;
+#endif
 
 	if (sock->sk == NULL)
 		return 0;
@@ -2701,10 +2788,15 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
 	case PF_INET6:
 		if (addrlen < sizeof(struct sockaddr_in6))
 			return -EINVAL;
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
-		rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
+#ifdef SMACK_IPV6_SECMARK_LABELING
+		rsp = smack_ipv6host_label(sip);
+		if (rsp != NULL)
+			rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
 						SMK_CONNECTING);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
+#ifdef SMACK_IPV6_PORT_LABELING
+		rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
+#endif
 		break;
 	}
 	return rc;
@@ -3590,9 +3682,13 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
 				int size)
 {
 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#if IS_ENABLED(CONFIG_IPV6)
 	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
+#ifdef SMACK_IPV6_SECMARK_LABELING
+	struct socket_smack *ssp = sock->sk->sk_security;
+	struct smack_known *rsp;
+#endif
 	int rc = 0;
 
 	/*
@@ -3606,9 +3702,15 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
 		rc = smack_netlabel_send(sock->sk, sip);
 		break;
 	case AF_INET6:
-#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
+#ifdef SMACK_IPV6_SECMARK_LABELING
+		rsp = smack_ipv6host_label(sap);
+		if (rsp != NULL)
+			rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
+						SMK_CONNECTING);
+#endif
+#ifdef SMACK_IPV6_PORT_LABELING
 		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
-#endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
 		break;
 	}
 	return rc;
@@ -3822,10 +3924,12 @@ access_check:
 		proto = smk_skb_to_addr_ipv6(skb, &sadd);
 		if (proto != IPPROTO_UDP && proto != IPPROTO_TCP)
 			break;
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_SECMARK_LABELING
 		if (skb && skb->secmark != 0)
 			skp = smack_from_secid(skb->secmark);
 		else
+			skp = smack_ipv6host_label(&sadd);
+		if (skp == NULL)
 			skp = smack_net_ambient;
 #ifdef CONFIG_AUDIT
 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
@@ -3836,9 +3940,10 @@ access_check:
 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
 		rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
 					MAY_WRITE, rc);
-#else /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_SECMARK_LABELING */
+#ifdef SMACK_IPV6_PORT_LABELING
 		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif /* SMACK_IPV6_PORT_LABELING */
 		break;
 #endif /* CONFIG_IPV6 */
 	}
@@ -3936,13 +4041,11 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 		}
 		netlbl_secattr_destroy(&secattr);
 		break;
-#if IS_ENABLED(CONFIG_IPV6)
 	case PF_INET6:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_SECMARK_LABELING
 		s = skb->secmark;
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
 		break;
-#endif /* CONFIG_IPV6 */
 	}
 	*secid = s;
 	if (s == 0)
@@ -4065,7 +4168,7 @@ access_check:
 	hdr = ip_hdr(skb);
 	addr.sin_addr.s_addr = hdr->saddr;
 	rcu_read_lock();
-	hskp = smack_host_label(&addr);
+	hskp = smack_ipv4host_label(&addr);
 	rcu_read_unlock();
 
 	if (hskp == NULL)
@@ -4517,9 +4620,9 @@ struct security_hook_list smack_hooks[] = {
 	LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
 
 	LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
-#ifndef CONFIG_SECURITY_SMACK_NETFILTER
+#ifdef SMACK_IPV6_PORT_LABELING
 	LSM_HOOK_INIT(socket_bind, smack_socket_bind),
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
+#endif
 	LSM_HOOK_INIT(socket_connect, smack_socket_connect),
 	LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
 	LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
@@ -4614,7 +4717,16 @@ static __init int smack_init(void)
 		return -ENOMEM;
 	}
 
-	printk(KERN_INFO "Smack:  Initializing.\n");
+	pr_info("Smack:  Initializing.\n");
+#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+	pr_info("Smack:  Netfilter enabled.\n");
+#endif
+#ifdef SMACK_IPV6_PORT_LABELING
+	pr_info("Smack:  IPv6 port labeling enabled.\n");
+#endif
+#ifdef SMACK_IPV6_SECMARK_LABELING
+	pr_info("Smack:  IPv6 Netfilter enabled.\n");
+#endif
 
 	/*
 	 * Set the security state for the initial task.
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 81a2888a9908..11b752b366ea 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -29,6 +29,7 @@
 #include <linux/magic.h>
 #include "smack.h"
 
+#define BEBITS	(sizeof(__be32) * 8)
 /*
  * smackfs pseudo filesystem.
  */
@@ -40,7 +41,7 @@ enum smk_inos {
 	SMK_DOI		= 5,	/* CIPSO DOI */
 	SMK_DIRECT	= 6,	/* CIPSO level indicating direct label */
 	SMK_AMBIENT	= 7,	/* internet ambient label */
-	SMK_NETLBLADDR	= 8,	/* single label hosts */
+	SMK_NET4ADDR	= 8,	/* single label hosts */
 	SMK_ONLYCAP	= 9,	/* the only "capable" label */
 	SMK_LOGGING	= 10,	/* logging */
 	SMK_LOAD_SELF	= 11,	/* task specific rules */
@@ -57,6 +58,9 @@ enum smk_inos {
 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
 	SMK_UNCONFINED	= 22,	/* define an unconfined label */
 #endif
+#if IS_ENABLED(CONFIG_IPV6)
+	SMK_NET6ADDR	= 23,	/* single label IPv6 hosts */
+#endif /* CONFIG_IPV6 */
 };
 
 /*
@@ -64,7 +68,10 @@ enum smk_inos {
  */
 static DEFINE_MUTEX(smack_cipso_lock);
 static DEFINE_MUTEX(smack_ambient_lock);
-static DEFINE_MUTEX(smk_netlbladdr_lock);
+static DEFINE_MUTEX(smk_net4addr_lock);
+#if IS_ENABLED(CONFIG_IPV6)
+static DEFINE_MUTEX(smk_net6addr_lock);
+#endif /* CONFIG_IPV6 */
 
 /*
  * This is the "ambient" label for network traffic.
@@ -118,7 +125,10 @@ int smack_ptrace_rule = SMACK_PTRACE_DEFAULT;
  * can write to the specified label.
  */
 
-LIST_HEAD(smk_netlbladdr_list);
+LIST_HEAD(smk_net4addr_list);
+#if IS_ENABLED(CONFIG_IPV6)
+LIST_HEAD(smk_net6addr_list);
+#endif /* CONFIG_IPV6 */
 
 /*
  * Rule lists are maintained for each label.
@@ -140,11 +150,6 @@ struct smack_parsed_rule {
 
 static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
 
-struct smack_known smack_cipso_option = {
-	.smk_known	= SMACK_CIPSO_OPTION,
-	.smk_secid	= 0,
-};
-
 /*
  * Values for parsing cipso rules
  * SMK_DIGITLEN: Length of a digit field in a rule.
@@ -1047,92 +1052,90 @@ static const struct file_operations smk_cipso2_ops = {
  * Seq_file read operations for /smack/netlabel
  */
 
-static void *netlbladdr_seq_start(struct seq_file *s, loff_t *pos)
+static void *net4addr_seq_start(struct seq_file *s, loff_t *pos)
 {
-	return smk_seq_start(s, pos, &smk_netlbladdr_list);
+	return smk_seq_start(s, pos, &smk_net4addr_list);
 }
 
-static void *netlbladdr_seq_next(struct seq_file *s, void *v, loff_t *pos)
+static void *net4addr_seq_next(struct seq_file *s, void *v, loff_t *pos)
 {
-	return smk_seq_next(s, v, pos, &smk_netlbladdr_list);
+	return smk_seq_next(s, v, pos, &smk_net4addr_list);
 }
-#define BEBITS	(sizeof(__be32) * 8)
 
 /*
  * Print host/label pairs
  */
-static int netlbladdr_seq_show(struct seq_file *s, void *v)
+static int net4addr_seq_show(struct seq_file *s, void *v)
 {
 	struct list_head *list = v;
-	struct smk_netlbladdr *skp =
-			list_entry_rcu(list, struct smk_netlbladdr, list);
-	unsigned char *hp = (char *) &skp->smk_host.sin_addr.s_addr;
-	int maskn;
-	u32 temp_mask = be32_to_cpu(skp->smk_mask.s_addr);
-
-	for (maskn = 0; temp_mask; temp_mask <<= 1, maskn++);
+	struct smk_net4addr *skp =
+			list_entry_rcu(list, struct smk_net4addr, list);
+	char *kp = SMACK_CIPSO_OPTION;
 
-	seq_printf(s, "%u.%u.%u.%u/%d %s\n",
-		hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label->smk_known);
+	if (skp->smk_label != NULL)
+		kp = skp->smk_label->smk_known;
+	seq_printf(s, "%pI4/%d %s\n", &skp->smk_host.s_addr,
+			skp->smk_masks, kp);
 
 	return 0;
 }
 
-static const struct seq_operations netlbladdr_seq_ops = {
-	.start = netlbladdr_seq_start,
-	.next  = netlbladdr_seq_next,
-	.show  = netlbladdr_seq_show,
+static const struct seq_operations net4addr_seq_ops = {
+	.start = net4addr_seq_start,
+	.next  = net4addr_seq_next,
+	.show  = net4addr_seq_show,
 	.stop  = smk_seq_stop,
 };
 
 /**
- * smk_open_netlbladdr - open() for /smack/netlabel
+ * smk_open_net4addr - open() for /smack/netlabel
  * @inode: inode structure representing file
  * @file: "netlabel" file pointer
  *
- * Connect our netlbladdr_seq_* operations with /smack/netlabel
+ * Connect our net4addr_seq_* operations with /smack/netlabel
  * file_operations
  */
-static int smk_open_netlbladdr(struct inode *inode, struct file *file)
+static int smk_open_net4addr(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &netlbladdr_seq_ops);
+	return seq_open(file, &net4addr_seq_ops);
 }
 
 /**
- * smk_netlbladdr_insert
+ * smk_net4addr_insert
  * @new : netlabel to insert
  *
- * This helper insert netlabel in the smack_netlbladdrs list
+ * This helper insert netlabel in the smack_net4addrs list
  * sorted by netmask length (longest to smallest)
- * locked by &smk_netlbladdr_lock in smk_write_netlbladdr
+ * locked by &smk_net4addr_lock in smk_write_net4addr
  *
  */
-static void smk_netlbladdr_insert(struct smk_netlbladdr *new)
+static void smk_net4addr_insert(struct smk_net4addr *new)
 {
-	struct smk_netlbladdr *m, *m_next;
+	struct smk_net4addr *m;
+	struct smk_net4addr *m_next;
 
-	if (list_empty(&smk_netlbladdr_list)) {
-		list_add_rcu(&new->list, &smk_netlbladdr_list);
+	if (list_empty(&smk_net4addr_list)) {
+		list_add_rcu(&new->list, &smk_net4addr_list);
 		return;
 	}
 
-	m = list_entry_rcu(smk_netlbladdr_list.next,
-			   struct smk_netlbladdr, list);
+	m = list_entry_rcu(smk_net4addr_list.next,
+			   struct smk_net4addr, list);
 
 	/* the comparison '>' is a bit hacky, but works */
-	if (new->smk_mask.s_addr > m->smk_mask.s_addr) {
-		list_add_rcu(&new->list, &smk_netlbladdr_list);
+	if (new->smk_masks > m->smk_masks) {
+		list_add_rcu(&new->list, &smk_net4addr_list);
 		return;
 	}
 
-	list_for_each_entry_rcu(m, &smk_netlbladdr_list, list) {
-		if (list_is_last(&m->list, &smk_netlbladdr_list)) {
+	list_for_each_entry_rcu(m, &smk_net4addr_list, list) {
+		if (list_is_last(&m->list, &smk_net4addr_list)) {
 			list_add_rcu(&new->list, &m->list);
 			return;
 		}
 		m_next = list_entry_rcu(m->list.next,
-					struct smk_netlbladdr, list);
-		if (new->smk_mask.s_addr > m_next->smk_mask.s_addr) {
+					struct smk_net4addr, list);
+		if (new->smk_masks > m_next->smk_masks) {
 			list_add_rcu(&new->list, &m->list);
 			return;
 		}
@@ -1141,28 +1144,29 @@ static void smk_netlbladdr_insert(struct smk_netlbladdr *new)
 
 
 /**
- * smk_write_netlbladdr - write() for /smack/netlabel
+ * smk_write_net4addr - write() for /smack/netlabel
  * @file: file pointer, not actually used
  * @buf: where to get the data from
  * @count: bytes sent
  * @ppos: where to start
  *
- * Accepts only one netlbladdr per write call.
+ * Accepts only one net4addr per write call.
  * Returns number of bytes written or error code, as appropriate
  */
-static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
+static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
-	struct smk_netlbladdr *snp;
+	struct smk_net4addr *snp;
 	struct sockaddr_in newname;
 	char *smack;
-	struct smack_known *skp;
+	struct smack_known *skp = NULL;
 	char *data;
 	char *host = (char *)&newname.sin_addr.s_addr;
 	int rc;
 	struct netlbl_audit audit_info;
 	struct in_addr mask;
 	unsigned int m;
+	unsigned int masks;
 	int found;
 	u32 mask_bits = (1<<31);
 	__be32 nsa;
@@ -1200,7 +1204,7 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	data[count] = '\0';
 
 	rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s",
-		&host[0], &host[1], &host[2], &host[3], &m, smack);
+		&host[0], &host[1], &host[2], &host[3], &masks, smack);
 	if (rc != 6) {
 		rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd %s",
 			&host[0], &host[1], &host[2], &host[3], smack);
@@ -1209,8 +1213,9 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 			goto free_out;
 		}
 		m = BEBITS;
+		masks = 32;
 	}
-	if (m > BEBITS) {
+	if (masks > BEBITS) {
 		rc = -EINVAL;
 		goto free_out;
 	}
@@ -1225,16 +1230,16 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 			goto free_out;
 		}
 	} else {
-		/* check known options */
-		if (strcmp(smack, smack_cipso_option.smk_known) == 0)
-			skp = &smack_cipso_option;
-		else {
+		/*
+		 * Only the -CIPSO option is supported for IPv4
+		 */
+		if (strcmp(smack, SMACK_CIPSO_OPTION) != 0) {
 			rc = -EINVAL;
 			goto free_out;
 		}
 	}
 
-	for (temp_mask = 0; m > 0; m--) {
+	for (m = masks, temp_mask = 0; m > 0; m--) {
 		temp_mask |= mask_bits;
 		mask_bits >>= 1;
 	}
@@ -1245,14 +1250,13 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	 * Only allow one writer at a time. Writes should be
 	 * quite rare and small in any case.
 	 */
-	mutex_lock(&smk_netlbladdr_lock);
+	mutex_lock(&smk_net4addr_lock);
 
 	nsa = newname.sin_addr.s_addr;
 	/* try to find if the prefix is already in the list */
 	found = 0;
-	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) {
-		if (snp->smk_host.sin_addr.s_addr == nsa &&
-		    snp->smk_mask.s_addr == mask.s_addr) {
+	list_for_each_entry_rcu(snp, &smk_net4addr_list, list) {
+		if (snp->smk_host.s_addr == nsa && snp->smk_masks == masks) {
 			found = 1;
 			break;
 		}
@@ -1265,17 +1269,20 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 			rc = -ENOMEM;
 		else {
 			rc = 0;
-			snp->smk_host.sin_addr.s_addr = newname.sin_addr.s_addr;
+			snp->smk_host.s_addr = newname.sin_addr.s_addr;
 			snp->smk_mask.s_addr = mask.s_addr;
 			snp->smk_label = skp;
-			smk_netlbladdr_insert(snp);
+			snp->smk_masks = masks;
+			smk_net4addr_insert(snp);
 		}
 	} else {
-		/* we delete the unlabeled entry, only if the previous label
-		 * wasn't the special CIPSO option */
-		if (snp->smk_label != &smack_cipso_option)
+		/*
+		 * Delete the unlabeled entry, only if the previous label
+		 * wasn't the special CIPSO option
+		 */
+		if (snp->smk_label != NULL)
 			rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
-					&snp->smk_host.sin_addr, &snp->smk_mask,
+					&snp->smk_host, &snp->smk_mask,
 					PF_INET, &audit_info);
 		else
 			rc = 0;
@@ -1287,15 +1294,279 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	 * this host so that incoming packets get labeled.
 	 * but only if we didn't get the special CIPSO option
 	 */
-	if (rc == 0 && skp != &smack_cipso_option)
+	if (rc == 0 && skp != NULL)
 		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
-			&snp->smk_host.sin_addr, &snp->smk_mask, PF_INET,
+			&snp->smk_host, &snp->smk_mask, PF_INET,
 			snp->smk_label->smk_secid, &audit_info);
 
 	if (rc == 0)
 		rc = count;
 
-	mutex_unlock(&smk_netlbladdr_lock);
+	mutex_unlock(&smk_net4addr_lock);
+
+free_out:
+	kfree(smack);
+free_data_out:
+	kfree(data);
+
+	return rc;
+}
+
+static const struct file_operations smk_net4addr_ops = {
+	.open           = smk_open_net4addr,
+	.read		= seq_read,
+	.llseek         = seq_lseek,
+	.write		= smk_write_net4addr,
+	.release        = seq_release,
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+/*
+ * Seq_file read operations for /smack/netlabel6
+ */
+
+static void *net6addr_seq_start(struct seq_file *s, loff_t *pos)
+{
+	return smk_seq_start(s, pos, &smk_net6addr_list);
+}
+
+static void *net6addr_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	return smk_seq_next(s, v, pos, &smk_net6addr_list);
+}
+
+/*
+ * Print host/label pairs
+ */
+static int net6addr_seq_show(struct seq_file *s, void *v)
+{
+	struct list_head *list = v;
+	struct smk_net6addr *skp =
+			 list_entry(list, struct smk_net6addr, list);
+
+	if (skp->smk_label != NULL)
+		seq_printf(s, "%pI6/%d %s\n", &skp->smk_host, skp->smk_masks,
+				skp->smk_label->smk_known);
+
+	return 0;
+}
+
+static const struct seq_operations net6addr_seq_ops = {
+	.start = net6addr_seq_start,
+	.next  = net6addr_seq_next,
+	.show  = net6addr_seq_show,
+	.stop  = smk_seq_stop,
+};
+
+/**
+ * smk_open_net6addr - open() for /smack/netlabel
+ * @inode: inode structure representing file
+ * @file: "netlabel" file pointer
+ *
+ * Connect our net6addr_seq_* operations with /smack/netlabel
+ * file_operations
+ */
+static int smk_open_net6addr(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &net6addr_seq_ops);
+}
+
+/**
+ * smk_net6addr_insert
+ * @new : entry to insert
+ *
+ * This inserts an entry in the smack_net6addrs list
+ * sorted by netmask length (longest to smallest)
+ * locked by &smk_net6addr_lock in smk_write_net6addr
+ *
+ */
+static void smk_net6addr_insert(struct smk_net6addr *new)
+{
+	struct smk_net6addr *m_next;
+	struct smk_net6addr *m;
+
+	if (list_empty(&smk_net6addr_list)) {
+		list_add_rcu(&new->list, &smk_net6addr_list);
+		return;
+	}
+
+	m = list_entry_rcu(smk_net6addr_list.next,
+			   struct smk_net6addr, list);
+
+	if (new->smk_masks > m->smk_masks) {
+		list_add_rcu(&new->list, &smk_net6addr_list);
+		return;
+	}
+
+	list_for_each_entry_rcu(m, &smk_net6addr_list, list) {
+		if (list_is_last(&m->list, &smk_net6addr_list)) {
+			list_add_rcu(&new->list, &m->list);
+			return;
+		}
+		m_next = list_entry_rcu(m->list.next,
+					struct smk_net6addr, list);
+		if (new->smk_masks > m_next->smk_masks) {
+			list_add_rcu(&new->list, &m->list);
+			return;
+		}
+	}
+}
+
+
+/**
+ * smk_write_net6addr - write() for /smack/netlabel
+ * @file: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Accepts only one net6addr per write call.
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	struct smk_net6addr *snp;
+	struct in6_addr newname;
+	struct in6_addr fullmask;
+	struct smack_known *skp = NULL;
+	char *smack;
+	char *data;
+	int rc = 0;
+	int found = 0;
+	int i;
+	unsigned int scanned[8];
+	unsigned int m;
+	unsigned int mask = 128;
+
+	/*
+	 * Must have privilege.
+	 * No partial writes.
+	 * Enough data must be present.
+	 * "<addr/mask, as a:b:c:d:e:f:g:h/e><space><label>"
+	 * "<addr, as a:b:c:d:e:f:g:h><space><label>"
+	 */
+	if (!smack_privileged(CAP_MAC_ADMIN))
+		return -EPERM;
+	if (*ppos != 0)
+		return -EINVAL;
+	if (count < SMK_NETLBLADDRMIN)
+		return -EINVAL;
+
+	data = kzalloc(count + 1, GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	if (copy_from_user(data, buf, count) != 0) {
+		rc = -EFAULT;
+		goto free_data_out;
+	}
+
+	smack = kzalloc(count + 1, GFP_KERNEL);
+	if (smack == NULL) {
+		rc = -ENOMEM;
+		goto free_data_out;
+	}
+
+	data[count] = '\0';
+
+	i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s",
+			&scanned[0], &scanned[1], &scanned[2], &scanned[3],
+			&scanned[4], &scanned[5], &scanned[6], &scanned[7],
+			&mask, smack);
+	if (i != 10) {
+		i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x %s",
+				&scanned[0], &scanned[1], &scanned[2],
+				&scanned[3], &scanned[4], &scanned[5],
+				&scanned[6], &scanned[7], smack);
+		if (i != 9) {
+			rc = -EINVAL;
+			goto free_out;
+		}
+	}
+	if (mask > 128) {
+		rc = -EINVAL;
+		goto free_out;
+	}
+	for (i = 0; i < 8; i++) {
+		if (scanned[i] > 0xffff) {
+			rc = -EINVAL;
+			goto free_out;
+		}
+		newname.s6_addr16[i] = htons(scanned[i]);
+	}
+
+	/*
+	 * If smack begins with '-', it is an option, don't import it
+	 */
+	if (smack[0] != '-') {
+		skp = smk_import_entry(smack, 0);
+		if (skp == NULL) {
+			rc = -EINVAL;
+			goto free_out;
+		}
+	} else {
+		/*
+		 * Only -DELETE is supported for IPv6
+		 */
+		if (strcmp(smack, SMACK_DELETE_OPTION) != 0) {
+			rc = -EINVAL;
+			goto free_out;
+		}
+	}
+
+	for (i = 0, m = mask; i < 8; i++) {
+		if (m >= 16) {
+			fullmask.s6_addr16[i] = 0xffff;
+			m -= 16;
+		} else if (m > 0) {
+			fullmask.s6_addr16[i] = (1 << m) - 1;
+			m = 0;
+		} else
+			fullmask.s6_addr16[i] = 0;
+		newname.s6_addr16[i] &= fullmask.s6_addr16[i];
+	}
+
+	/*
+	 * Only allow one writer at a time. Writes should be
+	 * quite rare and small in any case.
+	 */
+	mutex_lock(&smk_net6addr_lock);
+	/*
+	 * Try to find the prefix in the list
+	 */
+	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
+		if (mask != snp->smk_masks)
+			continue;
+		for (found = 1, i = 0; i < 8; i++) {
+			if (newname.s6_addr16[i] !=
+			    snp->smk_host.s6_addr16[i]) {
+				found = 0;
+				break;
+			}
+		}
+		if (found == 1)
+			break;
+	}
+	if (found == 0) {
+		snp = kzalloc(sizeof(*snp), GFP_KERNEL);
+		if (snp == NULL)
+			rc = -ENOMEM;
+		else {
+			snp->smk_host = newname;
+			snp->smk_mask = fullmask;
+			snp->smk_masks = mask;
+			snp->smk_label = skp;
+			smk_net6addr_insert(snp);
+		}
+	} else {
+		snp->smk_label = skp;
+	}
+
+	if (rc == 0)
+		rc = count;
+
+	mutex_unlock(&smk_net6addr_lock);
 
 free_out:
 	kfree(smack);
@@ -1305,13 +1576,14 @@ free_data_out:
 	return rc;
 }
 
-static const struct file_operations smk_netlbladdr_ops = {
-	.open           = smk_open_netlbladdr,
+static const struct file_operations smk_net6addr_ops = {
+	.open           = smk_open_net6addr,
 	.read		= seq_read,
 	.llseek         = seq_lseek,
-	.write		= smk_write_netlbladdr,
+	.write		= smk_write_net6addr,
 	.release        = seq_release,
 };
+#endif /* CONFIG_IPV6 */
 
 /**
  * smk_read_doi - read() for /smack/doi
@@ -2515,8 +2787,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
 			"direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
 		[SMK_AMBIENT] = {
 			"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
-		[SMK_NETLBLADDR] = {
-			"netlabel", &smk_netlbladdr_ops, S_IRUGO|S_IWUSR},
+		[SMK_NET4ADDR] = {
+			"netlabel", &smk_net4addr_ops, S_IRUGO|S_IWUSR},
 		[SMK_ONLYCAP] = {
 			"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
 		[SMK_LOGGING] = {
@@ -2548,6 +2820,10 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
 		[SMK_UNCONFINED] = {
 			"unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR},
 #endif
+#if IS_ENABLED(CONFIG_IPV6)
+		[SMK_NET6ADDR] = {
+			"ipv6host", &smk_net6addr_ops, S_IRUGO|S_IWUSR},
+#endif /* CONFIG_IPV6 */
 		/* last one */
 			{""}
 	};