3 files changed, 255 insertions, 123 deletions

diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
index 5d503eeb15a1..82f0f7588b46 100644
--- a/net/nfc/llcp/llcp.c
+++ b/net/nfc/llcp/llcp.c
@@ -45,7 +45,7 @@ void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
 	write_unlock(&l->lock);
 }
 
-static void nfc_llcp_socket_release(struct nfc_llcp_local *local)
+static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool listen)
 {
 	struct sock *sk;
 	struct hlist_node *node, *tmp;
@@ -78,6 +78,11 @@ static void nfc_llcp_socket_release(struct nfc_llcp_local *local)
 
 				sock_orphan(accept_sk);
 			}
+
+			if (listen == true) {
+				release_sock(sk);
+				continue;
+			}
 		}
 
 		sk->sk_state = LLCP_CLOSED;
@@ -106,7 +111,7 @@ static void local_release(struct kref *ref)
 	local = container_of(ref, struct nfc_llcp_local, ref);
 
 	list_del(&local->list);
-	nfc_llcp_socket_release(local);
+	nfc_llcp_socket_release(local, false);
 	del_timer_sync(&local->link_timer);
 	skb_queue_purge(&local->tx_queue);
 	destroy_workqueue(local->tx_wq);
@@ -118,23 +123,48 @@ static void local_release(struct kref *ref)
 
 int nfc_llcp_local_put(struct nfc_llcp_local *local)
 {
-	WARN_ON(local == NULL);
-
 	if (local == NULL)
 		return 0;
 
 	return kref_put(&local->ref, local_release);
 }
 
-static void nfc_llcp_clear_sdp(struct nfc_llcp_local *local)
+static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
+					       u8 ssap, u8 dsap)
 {
-	mutex_lock(&local->sdp_lock);
+	struct sock *sk;
+	struct hlist_node *node;
+	struct nfc_llcp_sock *llcp_sock;
 
-	local->local_wks = 0;
-	local->local_sdp = 0;
-	local->local_sap = 0;
+	pr_debug("ssap dsap %d %d\n", ssap, dsap);
 
-	mutex_unlock(&local->sdp_lock);
+	if (ssap == 0 && dsap == 0)
+		return NULL;
+
+	read_lock(&local->sockets.lock);
+
+	llcp_sock = NULL;
+
+	sk_for_each(sk, node, &local->sockets.head) {
+		llcp_sock = nfc_llcp_sock(sk);
+
+		if (llcp_sock->ssap == ssap && llcp_sock->dsap == dsap)
+			break;
+	}
+
+	read_unlock(&local->sockets.lock);
+
+	if (llcp_sock == NULL)
+		return NULL;
+
+	sock_hold(&llcp_sock->sk);
+
+	return llcp_sock;
+}
+
+static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
+{
+	sock_put(&sock->sk);
 }
 
 static void nfc_llcp_timeout_work(struct work_struct *work)
@@ -197,6 +227,51 @@ static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
 	return -EINVAL;
 }
 
+static
+struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
+					    u8 *sn, size_t sn_len)
+{
+	struct sock *sk;
+	struct hlist_node *node;
+	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
+
+	pr_debug("sn %zd %p\n", sn_len, sn);
+
+	if (sn == NULL || sn_len == 0)
+		return NULL;
+
+	read_lock(&local->sockets.lock);
+
+	llcp_sock = NULL;
+
+	sk_for_each(sk, node, &local->sockets.head) {
+		tmp_sock = nfc_llcp_sock(sk);
+
+		pr_debug("llcp sock %p\n", tmp_sock);
+
+		if (tmp_sock->sk.sk_state != LLCP_LISTEN)
+			continue;
+
+		if (tmp_sock->service_name == NULL ||
+		    tmp_sock->service_name_len == 0)
+			continue;
+
+		if (tmp_sock->service_name_len != sn_len)
+			continue;
+
+		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
+			llcp_sock = tmp_sock;
+			break;
+		}
+	}
+
+	read_unlock(&local->sockets.lock);
+
+	pr_debug("Found llcp sock %p\n", llcp_sock);
+
+	return llcp_sock;
+}
+
 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 			 struct nfc_llcp_sock *sock)
 {
@@ -223,41 +298,26 @@ u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 		}
 
 		/*
-		 * This is not a well known service,
-		 * we should try to find a local SDP free spot
+		 * Check if there already is a non WKS socket bound
+		 * to this service name.
 		 */
-		ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
-		if (ssap == LLCP_SDP_NUM_SAP) {
+		if (nfc_llcp_sock_from_sn(local, sock->service_name,
+					  sock->service_name_len) != NULL) {
 			mutex_unlock(&local->sdp_lock);
 
 			return LLCP_SAP_MAX;
 		}
 
-		pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
-
-		set_bit(ssap, &local->local_sdp);
 		mutex_unlock(&local->sdp_lock);
 
-		return LLCP_WKS_NUM_SAP + ssap;
-
-	} else if (sock->ssap != 0) {
-		if (sock->ssap < LLCP_WKS_NUM_SAP) {
-			if (!test_bit(sock->ssap, &local->local_wks)) {
-				set_bit(sock->ssap, &local->local_wks);
-				mutex_unlock(&local->sdp_lock);
-
-				return sock->ssap;
-			}
+		return LLCP_SDP_UNBOUND;
 
-		} else if (sock->ssap < LLCP_SDP_NUM_SAP) {
-			if (!test_bit(sock->ssap - LLCP_WKS_NUM_SAP,
-				      &local->local_sdp)) {
-				set_bit(sock->ssap - LLCP_WKS_NUM_SAP,
-					&local->local_sdp);
-				mutex_unlock(&local->sdp_lock);
+	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
+		if (!test_bit(sock->ssap, &local->local_wks)) {
+			set_bit(sock->ssap, &local->local_wks);
+			mutex_unlock(&local->sdp_lock);
 
-				return sock->ssap;
-			}
+			return sock->ssap;
 		}
 	}
 
@@ -294,8 +354,34 @@ void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
 		local_ssap = ssap;
 		sdp = &local->local_wks;
 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
+		atomic_t *client_cnt;
+
 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
 		sdp = &local->local_sdp;
+		client_cnt = &local->local_sdp_cnt[local_ssap];
+
+		pr_debug("%d clients\n", atomic_read(client_cnt));
+
+		mutex_lock(&local->sdp_lock);
+
+		if (atomic_dec_and_test(client_cnt)) {
+			struct nfc_llcp_sock *l_sock;
+
+			pr_debug("No more clients for SAP %d\n", ssap);
+
+			clear_bit(local_ssap, sdp);
+
+			/* Find the listening sock and set it back to UNBOUND */
+			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
+			if (l_sock) {
+				l_sock->ssap = LLCP_SDP_UNBOUND;
+				nfc_llcp_sock_put(l_sock);
+			}
+		}
+
+		mutex_unlock(&local->sdp_lock);
+
+		return;
 	} else if (ssap < LLCP_MAX_SAP) {
 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
 		sdp = &local->local_sap;
@@ -310,19 +396,26 @@ void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
 	mutex_unlock(&local->sdp_lock);
 }
 
-u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
+static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
 {
-	struct nfc_llcp_local *local;
+	u8 ssap;
 
-	local = nfc_llcp_find_local(dev);
-	if (local == NULL) {
-		*general_bytes_len = 0;
-		return NULL;
+	mutex_lock(&local->sdp_lock);
+
+	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
+	if (ssap == LLCP_SDP_NUM_SAP) {
+		mutex_unlock(&local->sdp_lock);
+
+		return LLCP_SAP_MAX;
 	}
 
-	*general_bytes_len = local->gb_len;
+	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
 
-	return local->gb;
+	set_bit(ssap, &local->local_sdp);
+
+	mutex_unlock(&local->sdp_lock);
+
+	return LLCP_WKS_NUM_SAP + ssap;
 }
 
 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
@@ -386,6 +479,23 @@ static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 	return 0;
 }
 
+u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
+{
+	struct nfc_llcp_local *local;
+
+	local = nfc_llcp_find_local(dev);
+	if (local == NULL) {
+		*general_bytes_len = 0;
+		return NULL;
+	}
+
+	nfc_llcp_build_gb(local);
+
+	*general_bytes_len = local->gb_len;
+
+	return local->gb;
+}
+
 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 {
 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
@@ -509,74 +619,12 @@ out:
 	return llcp_sock;
 }
 
-static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
-					       u8 ssap, u8 dsap)
-{
-	struct sock *sk;
-	struct hlist_node *node;
-	struct nfc_llcp_sock *llcp_sock;
-
-	pr_debug("ssap dsap %d %d\n", ssap, dsap);
-
-	if (ssap == 0 && dsap == 0)
-		return NULL;
-
-	read_lock(&local->sockets.lock);
-
-	llcp_sock = NULL;
-
-	sk_for_each(sk, node, &local->sockets.head) {
-		llcp_sock = nfc_llcp_sock(sk);
-
-		if (llcp_sock->ssap == ssap &&
-		    llcp_sock->dsap == dsap)
-			break;
-	}
-
-	read_unlock(&local->sockets.lock);
-
-	if (llcp_sock == NULL)
-		return NULL;
-
-	sock_hold(&llcp_sock->sk);
-
-	return llcp_sock;
-}
-
 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
 						  u8 *sn, size_t sn_len)
 {
-	struct sock *sk;
-	struct hlist_node *node;
 	struct nfc_llcp_sock *llcp_sock;
 
-	pr_debug("sn %zd\n", sn_len);
-
-	if (sn == NULL || sn_len == 0)
-		return NULL;
-
-	read_lock(&local->sockets.lock);
-
-	llcp_sock = NULL;
-
-	sk_for_each(sk, node, &local->sockets.head) {
-		llcp_sock = nfc_llcp_sock(sk);
-
-		if (llcp_sock->sk.sk_state != LLCP_LISTEN)
-			continue;
-
-		if (llcp_sock->service_name == NULL ||
-		    llcp_sock->service_name_len == 0)
-			continue;
-
-		if (llcp_sock->service_name_len != sn_len)
-			continue;
-
-		if (memcmp(sn, llcp_sock->service_name, sn_len) == 0)
-			break;
-	}
-
-	read_unlock(&local->sockets.lock);
+	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
 
 	if (llcp_sock == NULL)
 		return NULL;
@@ -586,11 +634,6 @@ static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
 	return llcp_sock;
 }
 
-static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
-{
-	sock_put(&sock->sk);
-}
-
 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
 {
 	u8 *tlv = &skb->data[2], type, length;
@@ -662,6 +705,21 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 		goto fail;
 	}
 
+	if (sock->ssap == LLCP_SDP_UNBOUND) {
+		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
+
+		pr_debug("First client, reserving %d\n", ssap);
+
+		if (ssap == LLCP_SAP_MAX) {
+			reason = LLCP_DM_REJ;
+			release_sock(&sock->sk);
+			sock_put(&sock->sk);
+			goto fail;
+		}
+
+		sock->ssap = ssap;
+	}
+
 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
 	if (new_sk == NULL) {
 		reason = LLCP_DM_REJ;
@@ -675,9 +733,21 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 	new_sock->local = nfc_llcp_local_get(local);
 	new_sock->miu = local->remote_miu;
 	new_sock->nfc_protocol = sock->nfc_protocol;
-	new_sock->ssap = sock->ssap;
 	new_sock->dsap = ssap;
+	new_sock->target_idx = local->target_idx;
 	new_sock->parent = parent;
+	new_sock->ssap = sock->ssap;
+	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
+		atomic_t *client_count;
+
+		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
+
+		client_count =
+			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
+
+		atomic_inc(client_count);
+		new_sock->reserved_ssap = sock->ssap;
+	}
 
 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
 				      skb->len - LLCP_HEADER_SIZE);
@@ -886,6 +956,45 @@ static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
 	nfc_llcp_sock_put(llcp_sock);
 }
 
+static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
+{
+	struct nfc_llcp_sock *llcp_sock;
+	struct sock *sk;
+	u8 dsap, ssap, reason;
+
+	dsap = nfc_llcp_dsap(skb);
+	ssap = nfc_llcp_ssap(skb);
+	reason = skb->data[2];
+
+	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
+
+	switch (reason) {
+	case LLCP_DM_NOBOUND:
+	case LLCP_DM_REJ:
+		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
+		break;
+
+	default:
+		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
+		break;
+	}
+
+	if (llcp_sock == NULL) {
+		pr_err("Invalid DM\n");
+		return;
+	}
+
+	sk = &llcp_sock->sk;
+
+	sk->sk_err = ENXIO;
+	sk->sk_state = LLCP_CLOSED;
+	sk->sk_state_change(sk);
+
+	nfc_llcp_sock_put(llcp_sock);
+
+	return;
+}
+
 static void nfc_llcp_rx_work(struct work_struct *work)
 {
 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
@@ -929,6 +1038,11 @@ static void nfc_llcp_rx_work(struct work_struct *work)
 		nfc_llcp_recv_cc(local, skb);
 		break;
 
+	case LLCP_PDU_DM:
+		pr_debug("DM\n");
+		nfc_llcp_recv_dm(local, skb);
+		break;
+
 	case LLCP_PDU_I:
 	case LLCP_PDU_RR:
 	case LLCP_PDU_RNR:
@@ -985,10 +1099,8 @@ void nfc_llcp_mac_is_down(struct nfc_dev *dev)
 	if (local == NULL)
 		return;
 
-	nfc_llcp_clear_sdp(local);
-
 	/* Close and purge all existing sockets */
-	nfc_llcp_socket_release(local);
+	nfc_llcp_socket_release(local, true);
 }
 
 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
diff --git a/net/nfc/llcp/llcp.h b/net/nfc/llcp/llcp.h
index 7286c86982ff..83b8bba5a280 100644
--- a/net/nfc/llcp/llcp.h
+++ b/net/nfc/llcp/llcp.h
@@ -37,6 +37,7 @@ enum llcp_state {
 #define LLCP_LOCAL_NUM_SAP 32
 #define LLCP_LOCAL_SAP_OFFSET (LLCP_WKS_NUM_SAP + LLCP_SDP_NUM_SAP)
 #define LLCP_MAX_SAP (LLCP_WKS_NUM_SAP + LLCP_SDP_NUM_SAP + LLCP_LOCAL_NUM_SAP)
+#define LLCP_SDP_UNBOUND   (LLCP_MAX_SAP + 1)
 
 struct nfc_llcp_sock;
 
@@ -69,6 +70,7 @@ struct nfc_llcp_local {
 	unsigned long local_wks;      /* Well known services */
 	unsigned long local_sdp;      /* Local services  */
 	unsigned long local_sap; /* Local SAPs, not available for discovery */
+	atomic_t local_sdp_cnt[LLCP_SDP_NUM_SAP];
 
 	/* local */
 	u8 gb[NFC_MAX_GT_LEN];
@@ -113,6 +115,9 @@ struct nfc_llcp_sock {
 	/* Is the remote peer ready to receive */
 	u8 remote_ready;
 
+	/* Reserved source SAP */
+	u8 reserved_ssap;
+
 	struct sk_buff_head tx_queue;
 	struct sk_buff_head tx_pending_queue;
 	struct sk_buff_head tx_backlog_queue;
diff --git a/net/nfc/llcp/sock.c b/net/nfc/llcp/sock.c
index 05ca5a680071..ddeb9aa398f0 100644
--- a/net/nfc/llcp/sock.c
+++ b/net/nfc/llcp/sock.c
@@ -78,11 +78,11 @@ static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
 	struct sockaddr_nfc_llcp llcp_addr;
 	int len, ret = 0;
 
-	pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);
-
 	if (!addr || addr->sa_family != AF_NFC)
 		return -EINVAL;
 
+	pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);
+
 	memset(&llcp_addr, 0, sizeof(llcp_addr));
 	len = min_t(unsigned int, sizeof(llcp_addr), alen);
 	memcpy(&llcp_addr, addr, len);
@@ -121,8 +121,12 @@ static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
 					  GFP_KERNEL);
 
 	llcp_sock->ssap = nfc_llcp_get_sdp_ssap(local, llcp_sock);
-	if (llcp_sock->ssap == LLCP_MAX_SAP)
+	if (llcp_sock->ssap == LLCP_SAP_MAX) {
+		ret = -EADDRINUSE;
 		goto put_dev;
+	}
+
+	llcp_sock->reserved_ssap = llcp_sock->ssap;
 
 	nfc_llcp_sock_link(&local->sockets, sk);
 
@@ -283,22 +287,28 @@ error:
 	return ret;
 }
 
-static int llcp_sock_getname(struct socket *sock, struct sockaddr *addr,
+static int llcp_sock_getname(struct socket *sock, struct sockaddr *uaddr,
 			     int *len, int peer)
 {
-	struct sockaddr_nfc_llcp *llcp_addr = (struct sockaddr_nfc_llcp *)addr;
 	struct sock *sk = sock->sk;
 	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
+	DECLARE_SOCKADDR(struct sockaddr_nfc_llcp *, llcp_addr, uaddr);
 
-	pr_debug("%p\n", sk);
+	if (llcp_sock == NULL || llcp_sock->dev == NULL)
+		return -EBADFD;
+
+	pr_debug("%p %d %d %d\n", sk, llcp_sock->target_idx,
+		 llcp_sock->dsap, llcp_sock->ssap);
 
 	if (llcp_sock == NULL || llcp_sock->dev == NULL)
 		return -EBADFD;
 
-	addr->sa_family = AF_NFC;
+	uaddr->sa_family = AF_NFC;
+
 	*len = sizeof(struct sockaddr_nfc_llcp);
 
 	llcp_addr->dev_idx = llcp_sock->dev->idx;
+	llcp_addr->target_idx = llcp_sock->target_idx;
 	llcp_addr->dsap = llcp_sock->dsap;
 	llcp_addr->ssap = llcp_sock->ssap;
 	llcp_addr->service_name_len = llcp_sock->service_name_len;
@@ -406,7 +416,8 @@ static int llcp_sock_release(struct socket *sock)
 		}
 	}
 
-	nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap);
+	if (llcp_sock->reserved_ssap < LLCP_SAP_MAX)
+		nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap);
 
 	release_sock(sk);
 
@@ -486,6 +497,9 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr,
 		ret = -ENOMEM;
 		goto put_dev;
 	}
+
+	llcp_sock->reserved_ssap = llcp_sock->ssap;
+
 	if (addr->service_name_len == 0)
 		llcp_sock->dsap = addr->dsap;
 	else
@@ -687,6 +701,7 @@ struct sock *nfc_llcp_sock_alloc(struct socket *sock, int type, gfp_t gfp)
 	llcp_sock->send_n = llcp_sock->send_ack_n = 0;
 	llcp_sock->recv_n = llcp_sock->recv_ack_n = 0;
 	llcp_sock->remote_ready = 1;
+	llcp_sock->reserved_ssap = LLCP_SAP_MAX;
 	skb_queue_head_init(&llcp_sock->tx_queue);
 	skb_queue_head_init(&llcp_sock->tx_pending_queue);
 	skb_queue_head_init(&llcp_sock->tx_backlog_queue);