Merge tag 'Smack-for-5.10' of git://github.com/cschaufler/smack-next

Pull smack updates from Casey Schaufler:
 "Two minor fixes and one performance enhancement to Smack. The
  performance improvement is significant and the new code is more like
  its counterpart in SELinux.

   - Two kernel test robot suggested clean-ups.

   - Teach Smack to use the IPv4 netlabel cache. This results in a
     12-14% improvement on TCP benchmarks"

* tag 'Smack-for-5.10' of git://github.com/cschaufler/smack-next:
  Smack: Remove unnecessary variable initialization
  Smack: Fix build when NETWORK_SECMARK is not set
  Smack: Use the netlabel cache
  Smack: Set socket labels only once
  Smack: Consolidate uses of secmark into a function

1 files changed, 148 insertions, 104 deletions

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 8c0893eb5aa8..5c90b9fa4d40 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2383,38 +2383,31 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
 }
 
 /**
- * smack_netlabel - Set the secattr on a socket
+ * smack_netlbl_add - Set the secattr on a socket
  * @sk: the socket
- * @labeled: socket label scheme
  *
- * Convert the outbound smack value (smk_out) to a
- * secattr and attach it to the socket.
+ * Attach the outbound smack value (smk_out) to the socket.
  *
  * Returns 0 on success or an error code
  */
-static int smack_netlabel(struct sock *sk, int labeled)
+static int smack_netlbl_add(struct sock *sk)
 {
-	struct smack_known *skp;
 	struct socket_smack *ssp = sk->sk_security;
-	int rc = 0;
+	struct smack_known *skp = ssp->smk_out;
+	int rc;
 
-	/*
-	 * Usually the netlabel code will handle changing the
-	 * packet labeling based on the label.
-	 * The case of a single label host is different, because
-	 * a single label host should never get a labeled packet
-	 * even though the label is usually associated with a packet
-	 * label.
-	 */
 	local_bh_disable();
 	bh_lock_sock_nested(sk);
 
-	if (ssp->smk_out == smack_net_ambient ||
-	    labeled == SMACK_UNLABELED_SOCKET)
-		netlbl_sock_delattr(sk);
-	else {
-		skp = ssp->smk_out;
-		rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
+	rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
+	switch (rc) {
+	case 0:
+		ssp->smk_state = SMK_NETLBL_LABELED;
+		break;
+	case -EDESTADDRREQ:
+		ssp->smk_state = SMK_NETLBL_REQSKB;
+		rc = 0;
+		break;
 	}
 
 	bh_unlock_sock(sk);
@@ -2424,7 +2417,31 @@ static int smack_netlabel(struct sock *sk, int labeled)
 }
 
 /**
- * smack_netlbel_send - Set the secattr on a socket and perform access checks
+ * smack_netlbl_delete - Remove the secattr from a socket
+ * @sk: the socket
+ *
+ * Remove the outbound smack value from a socket
+ */
+static void smack_netlbl_delete(struct sock *sk)
+{
+	struct socket_smack *ssp = sk->sk_security;
+
+	/*
+	 * Take the label off the socket if one is set.
+	 */
+	if (ssp->smk_state != SMK_NETLBL_LABELED)
+		return;
+
+	local_bh_disable();
+	bh_lock_sock_nested(sk);
+	netlbl_sock_delattr(sk);
+	bh_unlock_sock(sk);
+	local_bh_enable();
+	ssp->smk_state = SMK_NETLBL_UNLABELED;
+}
+
+/**
+ * smk_ipv4_check - Perform IPv4 host access checks
  * @sk: the socket
  * @sap: the destination address
  *
@@ -2434,11 +2451,10 @@ static int smack_netlabel(struct sock *sk, int labeled)
  * Returns 0 on success or an error code.
  *
  */
-static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
+static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
 {
 	struct smack_known *skp;
-	int rc;
-	int sk_lbl;
+	int rc = 0;
 	struct smack_known *hkp;
 	struct socket_smack *ssp = sk->sk_security;
 	struct smk_audit_info ad;
@@ -2454,19 +2470,18 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
 		ad.a.u.net->dport = sap->sin_port;
 		ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
 #endif
-		sk_lbl = SMACK_UNLABELED_SOCKET;
 		skp = ssp->smk_out;
 		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
 		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
-	} else {
-		sk_lbl = SMACK_CIPSO_SOCKET;
-		rc = 0;
+		/*
+		 * Clear the socket netlabel if it's set.
+		 */
+		if (!rc)
+			smack_netlbl_delete(sk);
 	}
 	rcu_read_unlock();
-	if (rc != 0)
-		return rc;
 
-	return smack_netlabel(sk, sk_lbl);
+	return rc;
 }
 
 /**
@@ -2703,7 +2718,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
 		ssp->smk_out = skp;
 		if (sock->sk->sk_family == PF_INET) {
-			rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
+			rc = smack_netlbl_add(sock->sk);
 			if (rc != 0)
 				printk(KERN_WARNING
 					"Smack: \"%s\" netlbl error %d.\n",
@@ -2754,7 +2769,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
 	/*
 	 * Set the outbound netlbl.
 	 */
-	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
+	return smack_netlbl_add(sock->sk);
 }
 
 /**
@@ -2845,7 +2860,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
 	}
 	if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
 		return 0;
-	rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
+	rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
 	return rc;
 }
 
@@ -3663,7 +3678,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
 		if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
 		    sip->sin_family != AF_INET)
 			return -EINVAL;
-		rc = smack_netlabel_send(sock->sk, sip);
+		rc = smk_ipv4_check(sock->sk, sip);
 		break;
 #if IS_ENABLED(CONFIG_IPV6)
 	case AF_INET6:
@@ -3700,6 +3715,18 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
 	int acat;
 	int kcat;
 
+	/*
+	 * Netlabel found it in the cache.
+	 */
+	if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
+		return (struct smack_known *)sap->cache->data;
+
+	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
+		/*
+		 * Looks like a fallback, which gives us a secid.
+		 */
+		return smack_from_secid(sap->attr.secid);
+
 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
 		/*
 		 * Looks like a CIPSO packet.
@@ -3747,11 +3774,6 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
 			return &smack_known_web;
 		return &smack_known_star;
 	}
-	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
-		/*
-		 * Looks like a fallback, which gives us a secid.
-		 */
-		return smack_from_secid(sap->attr.secid);
 	/*
 	 * Without guidance regarding the smack value
 	 * for the packet fall back on the network
@@ -3811,6 +3833,62 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
 #endif /* CONFIG_IPV6 */
 
 /**
+ * smack_from_skb - Smack data from the secmark in an skb
+ * @skb: packet
+ *
+ * Returns smack_known of the secmark or NULL if that won't work.
+ */
+#ifdef CONFIG_NETWORK_SECMARK
+static struct smack_known *smack_from_skb(struct sk_buff *skb)
+{
+	if (skb == NULL || skb->secmark == 0)
+		return NULL;
+
+	return smack_from_secid(skb->secmark);
+}
+#else
+static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
+{
+	return NULL;
+}
+#endif
+
+/**
+ * smack_from_netlbl - Smack data from the IP options in an skb
+ * @sk: socket data came in on
+ * @family: address family
+ * @skb: packet
+ *
+ * Find the Smack label in the IP options. If it hasn't been
+ * added to the netlabel cache, add it here.
+ *
+ * Returns smack_known of the IP options or NULL if that won't work.
+ */
+static struct smack_known *smack_from_netlbl(struct sock *sk, u16 family,
+					     struct sk_buff *skb)
+{
+	struct netlbl_lsm_secattr secattr;
+	struct socket_smack *ssp = NULL;
+	struct smack_known *skp = NULL;
+	int rc;
+
+	netlbl_secattr_init(&secattr);
+
+	if (sk)
+		ssp = sk->sk_security;
+
+	if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
+		skp = smack_from_secattr(&secattr, ssp);
+		if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
+			rc = netlbl_cache_add(skb, family, &skp->smk_netlabel);
+	}
+
+	netlbl_secattr_destroy(&secattr);
+
+	return skp;
+}
+
+/**
  * smack_socket_sock_rcv_skb - Smack packet delivery access check
  * @sk: socket
  * @skb: packet
@@ -3819,7 +3897,6 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
  */
 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
-	struct netlbl_lsm_secattr secattr;
 	struct socket_smack *ssp = sk->sk_security;
 	struct smack_known *skp = NULL;
 	int rc = 0;
@@ -3838,33 +3915,18 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 	switch (family) {
 	case PF_INET:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 		/*
 		 * If there is a secmark use it rather than the CIPSO label.
 		 * If there is no secmark fall back to CIPSO.
 		 * The secmark is assumed to reflect policy better.
 		 */
-		if (skb && skb->secmark != 0) {
-			skp = smack_from_secid(skb->secmark);
-			goto access_check;
+		skp = smack_from_skb(skb);
+		if (skp == NULL) {
+			skp = smack_from_netlbl(sk, family, skb);
+			if (skp == NULL)
+				skp = smack_net_ambient;
 		}
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
-		/*
-		 * Translate what netlabel gave us.
-		 */
-		netlbl_secattr_init(&secattr);
 
-		rc = netlbl_skbuff_getattr(skb, family, &secattr);
-		if (rc == 0)
-			skp = smack_from_secattr(&secattr, ssp);
-		else
-			skp = smack_net_ambient;
-
-		netlbl_secattr_destroy(&secattr);
-
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
-access_check:
-#endif
 #ifdef CONFIG_AUDIT
 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
 		ad.a.u.net->family = family;
@@ -3890,16 +3952,14 @@ access_check:
 		    proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
 			break;
 #ifdef SMACK_IPV6_SECMARK_LABELING
-		if (skb && skb->secmark != 0)
-			skp = smack_from_secid(skb->secmark);
-		else if (smk_ipv6_localhost(&sadd))
-			break;
-		else
+		skp = smack_from_skb(skb);
+		if (skp == NULL) {
+			if (smk_ipv6_localhost(&sadd))
+				break;
 			skp = smack_ipv6host_label(&sadd);
-		if (skp == NULL)
-			skp = smack_net_ambient;
-		if (skb == NULL)
-			break;
+			if (skp == NULL)
+				skp = smack_net_ambient;
+		}
 #ifdef CONFIG_AUDIT
 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
 		ad.a.u.net->family = family;
@@ -3971,12 +4031,11 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 					 struct sk_buff *skb, u32 *secid)
 
 {
-	struct netlbl_lsm_secattr secattr;
 	struct socket_smack *ssp = NULL;
 	struct smack_known *skp;
+	struct sock *sk = NULL;
 	int family = PF_UNSPEC;
 	u32 s = 0;	/* 0 is the invalid secid */
-	int rc;
 
 	if (skb != NULL) {
 		if (skb->protocol == htons(ETH_P_IP))
@@ -3995,27 +4054,25 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 		s = ssp->smk_out->smk_secid;
 		break;
 	case PF_INET:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
-		s = skb->secmark;
-		if (s != 0)
+		skp = smack_from_skb(skb);
+		if (skp) {
+			s = skp->smk_secid;
 			break;
-#endif
+		}
 		/*
 		 * Translate what netlabel gave us.
 		 */
-		if (sock != NULL && sock->sk != NULL)
-			ssp = sock->sk->sk_security;
-		netlbl_secattr_init(&secattr);
-		rc = netlbl_skbuff_getattr(skb, family, &secattr);
-		if (rc == 0) {
-			skp = smack_from_secattr(&secattr, ssp);
+		if (sock != NULL)
+			sk = sock->sk;
+		skp = smack_from_netlbl(sk, family, skb);
+		if (skp != NULL)
 			s = skp->smk_secid;
-		}
-		netlbl_secattr_destroy(&secattr);
 		break;
 	case PF_INET6:
 #ifdef SMACK_IPV6_SECMARK_LABELING
-		s = skb->secmark;
+		skp = smack_from_skb(skb);
+		if (skp)
+			s = skp->smk_secid;
 #endif
 		break;
 	}
@@ -4063,7 +4120,6 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 	u16 family = sk->sk_family;
 	struct smack_known *skp;
 	struct socket_smack *ssp = sk->sk_security;
-	struct netlbl_lsm_secattr secattr;
 	struct sockaddr_in addr;
 	struct iphdr *hdr;
 	struct smack_known *hskp;
@@ -4087,29 +4143,17 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 	}
 #endif /* CONFIG_IPV6 */
 
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 	/*
 	 * If there is a secmark use it rather than the CIPSO label.
 	 * If there is no secmark fall back to CIPSO.
 	 * The secmark is assumed to reflect policy better.
 	 */
-	if (skb && skb->secmark != 0) {
-		skp = smack_from_secid(skb->secmark);
-		goto access_check;
+	skp = smack_from_skb(skb);
+	if (skp == NULL) {
+		skp = smack_from_netlbl(sk, family, skb);
+		if (skp == NULL)
+			skp = &smack_known_huh;
 	}
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
-
-	netlbl_secattr_init(&secattr);
-	rc = netlbl_skbuff_getattr(skb, family, &secattr);
-	if (rc == 0)
-		skp = smack_from_secattr(&secattr, ssp);
-	else
-		skp = &smack_known_huh;
-	netlbl_secattr_destroy(&secattr);
-
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
-access_check:
-#endif
 
 #ifdef CONFIG_AUDIT
 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);