1 files changed, 189 insertions, 283 deletions

diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index cc7194e05a15..b8acec0d596e 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -129,6 +129,8 @@ static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
 		set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 	}
 
+	list_add(&call->sock_link, &rx->sock_calls);
+
 	write_unlock(&rx->call_lock);
 
 	write_lock(&rxrpc_call_lock);
@@ -186,6 +188,12 @@ void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
 		return;
 	rx->backlog = NULL;
 
+	/* Make sure that there aren't any incoming calls in progress before we
+	 * clear the preallocation buffers.
+	 */
+	spin_lock_bh(&rx->incoming_lock);
+	spin_unlock_bh(&rx->incoming_lock);
+
 	head = b->peer_backlog_head;
 	tail = b->peer_backlog_tail;
 	while (CIRC_CNT(head, tail, size) > 0) {
@@ -224,251 +232,179 @@ void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
 }
 
 /*
- * generate a connection-level abort
+ * Allocate a new incoming call from the prealloc pool, along with a connection
+ * and a peer as necessary.
  */
-static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx,
-		      struct rxrpc_wire_header *whdr)
+static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
+						    struct rxrpc_local *local,
+						    struct rxrpc_connection *conn,
+						    struct sk_buff *skb)
 {
-	struct msghdr msg;
-	struct kvec iov[1];
-	size_t len;
-	int ret;
-
-	_enter("%d,,", local->debug_id);
-
-	whdr->type	= RXRPC_PACKET_TYPE_BUSY;
-	whdr->serial	= htonl(1);
-
-	msg.msg_name	= &srx->transport.sin;
-	msg.msg_namelen	= sizeof(srx->transport.sin);
-	msg.msg_control	= NULL;
-	msg.msg_controllen = 0;
-	msg.msg_flags	= 0;
-
-	iov[0].iov_base	= whdr;
-	iov[0].iov_len	= sizeof(*whdr);
-
-	len = iov[0].iov_len;
-
-	_proto("Tx BUSY %%1");
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_peer *peer, *xpeer;
+	struct rxrpc_call *call;
+	unsigned short call_head, conn_head, peer_head;
+	unsigned short call_tail, conn_tail, peer_tail;
+	unsigned short call_count, conn_count;
+
+	/* #calls >= #conns >= #peers must hold true. */
+	call_head = smp_load_acquire(&b->call_backlog_head);
+	call_tail = b->call_backlog_tail;
+	call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
+	conn_head = smp_load_acquire(&b->conn_backlog_head);
+	conn_tail = b->conn_backlog_tail;
+	conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
+	ASSERTCMP(conn_count, >=, call_count);
+	peer_head = smp_load_acquire(&b->peer_backlog_head);
+	peer_tail = b->peer_backlog_tail;
+	ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
+		  conn_count);
+
+	if (call_count == 0)
+		return NULL;
+
+	if (!conn) {
+		/* No connection.  We're going to need a peer to start off
+		 * with.  If one doesn't yet exist, use a spare from the
+		 * preallocation set.  We dump the address into the spare in
+		 * anticipation - and to save on stack space.
+		 */
+		xpeer = b->peer_backlog[peer_tail];
+		if (rxrpc_extract_addr_from_skb(&xpeer->srx, skb) < 0)
+			return NULL;
+
+		peer = rxrpc_lookup_incoming_peer(local, xpeer);
+		if (peer == xpeer) {
+			b->peer_backlog[peer_tail] = NULL;
+			smp_store_release(&b->peer_backlog_tail,
+					  (peer_tail + 1) &
+					  (RXRPC_BACKLOG_MAX - 1));
+		}
 
-	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
-	if (ret < 0) {
-		_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
-		return -EAGAIN;
+		/* Now allocate and set up the connection */
+		conn = b->conn_backlog[conn_tail];
+		b->conn_backlog[conn_tail] = NULL;
+		smp_store_release(&b->conn_backlog_tail,
+				  (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+		rxrpc_get_local(local);
+		conn->params.local = local;
+		conn->params.peer = peer;
+		rxrpc_new_incoming_connection(conn, skb);
+	} else {
+		rxrpc_get_connection(conn);
 	}
 
-	_leave(" = 0");
-	return 0;
+	/* And now we can allocate and set up a new call */
+	call = b->call_backlog[call_tail];
+	b->call_backlog[call_tail] = NULL;
+	smp_store_release(&b->call_backlog_tail,
+			  (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+
+	call->conn = conn;
+	call->peer = rxrpc_get_peer(conn->params.peer);
+	return call;
 }
 
 /*
- * accept an incoming call that needs peer, transport and/or connection setting
- * up
+ * Set up a new incoming call.  Called in BH context with the RCU read lock
+ * held.
+ *
+ * If this is for a kernel service, when we allocate the call, it will have
+ * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
+ * retainer ref obtained from the backlog buffer.  Prealloc calls for userspace
+ * services only have the ref from the backlog buffer.  We want to pass this
+ * ref to non-BH context to dispose of.
+ *
+ * If we want to report an error, we mark the skb with the packet type and
+ * abort code and return NULL.
  */
-static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
-				      struct rxrpc_sock *rx,
-				      struct sk_buff *skb,
-				      struct sockaddr_rxrpc *srx)
+struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
+					   struct rxrpc_connection *conn,
+					   struct sk_buff *skb)
 {
-	struct rxrpc_connection *conn;
-	struct rxrpc_skb_priv *sp, *nsp;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_sock *rx;
 	struct rxrpc_call *call;
-	struct sk_buff *notification;
-	int ret;
 
 	_enter("");
 
-	sp = rxrpc_skb(skb);
-
-	/* get a notification message to send to the server app */
-	notification = alloc_skb(0, GFP_NOFS);
-	if (!notification) {
-		_debug("no memory");
-		ret = -ENOMEM;
-		goto error_nofree;
-	}
-	rxrpc_new_skb(notification);
-	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
-
-	conn = rxrpc_incoming_connection(local, srx, skb);
-	if (IS_ERR(conn)) {
-		_debug("no conn");
-		ret = PTR_ERR(conn);
-		goto error;
-	}
-
-	call = rxrpc_incoming_call(rx, conn, skb);
-	rxrpc_put_connection(conn);
-	if (IS_ERR(call)) {
-		_debug("no call");
-		ret = PTR_ERR(call);
-		goto error;
+	/* Get the socket providing the service */
+	hlist_for_each_entry_rcu_bh(rx, &local->services, listen_link) {
+		if (rx->srx.srx_service == sp->hdr.serviceId)
+			goto found_service;
 	}
 
-	/* attach the call to the socket */
-	read_lock_bh(&local->services_lock);
-	if (rx->sk.sk_state == RXRPC_CLOSE)
-		goto invalid_service;
-
-	write_lock(&rx->call_lock);
-	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
-		rxrpc_get_call(call, rxrpc_call_got);
-
-		spin_lock(&call->conn->state_lock);
-		if (sp->hdr.securityIndex > 0 &&
-		    call->conn->state == RXRPC_CONN_SERVICE_UNSECURED) {
-			_debug("await conn sec");
-			list_add_tail(&call->accept_link, &rx->secureq);
-			call->conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
-			set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
-			rxrpc_queue_conn(call->conn);
-		} else {
-			_debug("conn ready");
-			call->state = RXRPC_CALL_SERVER_ACCEPTING;
-			list_add_tail(&call->accept_link, &rx->acceptq);
-			rxrpc_get_call_for_skb(call, notification);
-			nsp = rxrpc_skb(notification);
-			nsp->call = call;
-
-			ASSERTCMP(atomic_read(&call->usage), >=, 3);
-
-			_debug("notify");
-			spin_lock(&call->lock);
-			ret = rxrpc_queue_rcv_skb(call, notification, true,
-						  false);
-			spin_unlock(&call->lock);
-			notification = NULL;
-			BUG_ON(ret < 0);
-		}
-		spin_unlock(&call->conn->state_lock);
+	trace_rxrpc_abort("INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  RX_INVALID_OPERATION, EOPNOTSUPP);
+	skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
+	skb->priority = RX_INVALID_OPERATION;
+	_leave(" = NULL [service]");
+	return NULL;
 
-		_debug("queued");
+found_service:
+	spin_lock(&rx->incoming_lock);
+	if (rx->sk.sk_state == RXRPC_CLOSE) {
+		trace_rxrpc_abort("CLS", sp->hdr.cid, sp->hdr.callNumber,
+				  sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
+		skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
+		skb->priority = RX_INVALID_OPERATION;
+		_leave(" = NULL [close]");
+		call = NULL;
+		goto out;
 	}
-	write_unlock(&rx->call_lock);
 
-	_debug("process");
-	rxrpc_fast_process_packet(call, skb);
-
-	_debug("done");
-	read_unlock_bh(&local->services_lock);
-	rxrpc_free_skb(notification);
-	rxrpc_put_call(call, rxrpc_call_put);
-	_leave(" = 0");
-	return 0;
-
-invalid_service:
-	_debug("invalid");
-	read_unlock_bh(&local->services_lock);
-
-	rxrpc_release_call(rx, call);
-	rxrpc_put_call(call, rxrpc_call_put);
-	ret = -ECONNREFUSED;
-error:
-	rxrpc_free_skb(notification);
-error_nofree:
-	_leave(" = %d", ret);
-	return ret;
-}
+	call = rxrpc_alloc_incoming_call(rx, local, conn, skb);
+	if (!call) {
+		skb->mark = RXRPC_SKB_MARK_BUSY;
+		_leave(" = NULL [busy]");
+		call = NULL;
+		goto out;
+	}
 
-/*
- * accept incoming calls that need peer, transport and/or connection setting up
- * - the packets we get are all incoming client DATA packets that have seq == 1
- */
-void rxrpc_accept_incoming_calls(struct rxrpc_local *local)
-{
-	struct rxrpc_skb_priv *sp;
-	struct sockaddr_rxrpc srx;
-	struct rxrpc_sock *rx;
-	struct rxrpc_wire_header whdr;
-	struct sk_buff *skb;
-	int ret;
+	/* Make the call live. */
+	rxrpc_incoming_call(rx, call, skb);
+	conn = call->conn;
 
-	_enter("%d", local->debug_id);
+	if (rx->notify_new_call)
+		rx->notify_new_call(&rx->sk, call, call->user_call_ID);
 
-	skb = skb_dequeue(&local->accept_queue);
-	if (!skb) {
-		_leave("\n");
-		return;
-	}
+	spin_lock(&conn->state_lock);
+	switch (conn->state) {
+	case RXRPC_CONN_SERVICE_UNSECURED:
+		conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
+		set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
+		rxrpc_queue_conn(call->conn);
+		break;
 
-	_net("incoming call skb %p", skb);
-
-	rxrpc_see_skb(skb);
-	sp = rxrpc_skb(skb);
-
-	/* Set up a response packet header in case we need it */
-	whdr.epoch	= htonl(sp->hdr.epoch);
-	whdr.cid	= htonl(sp->hdr.cid);
-	whdr.callNumber	= htonl(sp->hdr.callNumber);
-	whdr.seq	= htonl(sp->hdr.seq);
-	whdr.serial	= 0;
-	whdr.flags	= 0;
-	whdr.type	= 0;
-	whdr.userStatus	= 0;
-	whdr.securityIndex = sp->hdr.securityIndex;
-	whdr._rsvd	= 0;
-	whdr.serviceId	= htons(sp->hdr.serviceId);
-
-	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
-		goto drop;
-
-	/* get the socket providing the service */
-	read_lock_bh(&local->services_lock);
-	hlist_for_each_entry(rx, &local->services, listen_link) {
-		if (rx->srx.srx_service == sp->hdr.serviceId &&
-		    rx->sk.sk_state != RXRPC_CLOSE)
-			goto found_service;
-	}
-	read_unlock_bh(&local->services_lock);
-	goto invalid_service;
+	case RXRPC_CONN_SERVICE:
+		write_lock(&call->state_lock);
+		if (rx->discard_new_call)
+			call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
+		else
+			call->state = RXRPC_CALL_SERVER_ACCEPTING;
+		write_unlock(&call->state_lock);
+		break;
 
-found_service:
-	_debug("found service %hd", rx->srx.srx_service);
-	if (sk_acceptq_is_full(&rx->sk))
-		goto backlog_full;
-	sk_acceptq_added(&rx->sk);
-	read_unlock_bh(&local->services_lock);
-
-	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
-	if (ret < 0)
-		sk_acceptq_removed(&rx->sk);
-	switch (ret) {
-	case -ECONNRESET: /* old calls are ignored */
-	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
-	case 0:
-		return;
-	case -ECONNREFUSED:
-		goto invalid_service;
-	case -EBUSY:
-		goto busy;
-	case -EKEYREJECTED:
-		goto security_mismatch;
+	case RXRPC_CONN_REMOTELY_ABORTED:
+		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+					  conn->remote_abort, ECONNABORTED);
+		break;
+	case RXRPC_CONN_LOCALLY_ABORTED:
+		rxrpc_abort_call("CON", call, sp->hdr.seq,
+				 conn->local_abort, ECONNABORTED);
+		break;
 	default:
 		BUG();
 	}
+	spin_unlock(&conn->state_lock);
 
-backlog_full:
-	read_unlock_bh(&local->services_lock);
-busy:
-	rxrpc_busy(local, &srx, &whdr);
-	rxrpc_free_skb(skb);
-	return;
-
-drop:
-	rxrpc_free_skb(skb);
-	return;
+	if (call->state == RXRPC_CALL_SERVER_ACCEPTING)
+		rxrpc_notify_socket(call);
 
-invalid_service:
-	skb->priority = RX_INVALID_OPERATION;
-	rxrpc_reject_packet(local, skb);
-	return;
-
-	/* can't change connection security type mid-flow */
-security_mismatch:
-	skb->priority = RX_PROTOCOL_ERROR;
-	rxrpc_reject_packet(local, skb);
-	return;
+	_leave(" = %p{%d}", call, call->debug_id);
+out:
+	spin_unlock(&rx->incoming_lock);
+	return call;
 }
 
 /*
@@ -490,11 +426,10 @@ struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
 	write_lock(&rx->call_lock);
 
 	ret = -ENODATA;
-	if (list_empty(&rx->acceptq))
+	if (list_empty(&rx->to_be_accepted))
 		goto out;
 
 	/* check the user ID isn't already in use */
-	ret = -EBADSLT;
 	pp = &rx->calls.rb_node;
 	parent = NULL;
 	while (*pp) {
@@ -506,11 +441,14 @@ struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
 		else if (user_call_ID > call->user_call_ID)
 			pp = &(*pp)->rb_right;
 		else
-			goto out;
+			goto id_in_use;
 	}
 
-	/* dequeue the first call and check it's still valid */
-	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
+	/* Dequeue the first call and check it's still valid.  We gain
+	 * responsibility for the queue's reference.
+	 */
+	call = list_entry(rx->to_be_accepted.next,
+			  struct rxrpc_call, accept_link);
 	list_del_init(&call->accept_link);
 	sk_acceptq_removed(&rx->sk);
 	rxrpc_see_call(call);
@@ -528,31 +466,35 @@ struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
 	}
 
 	/* formalise the acceptance */
-	rxrpc_get_call(call, rxrpc_call_got_userid);
+	rxrpc_get_call(call, rxrpc_call_got);
 	call->notify_rx = notify_rx;
 	call->user_call_ID = user_call_ID;
+	rxrpc_get_call(call, rxrpc_call_got_userid);
 	rb_link_node(&call->sock_node, parent, pp);
 	rb_insert_color(&call->sock_node, &rx->calls);
 	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
 		BUG();
-	if (test_and_set_bit(RXRPC_CALL_EV_ACCEPTED, &call->events))
-		BUG();
 
 	write_unlock_bh(&call->state_lock);
 	write_unlock(&rx->call_lock);
-	rxrpc_queue_call(call);
+	rxrpc_notify_socket(call);
+	rxrpc_service_prealloc(rx, GFP_KERNEL);
 	_leave(" = %p{%d}", call, call->debug_id);
 	return call;
 
 out_release:
+	_debug("release %p", call);
 	write_unlock_bh(&call->state_lock);
 	write_unlock(&rx->call_lock);
-	_debug("release %p", call);
 	rxrpc_release_call(rx, call);
-	_leave(" = %d", ret);
-	return ERR_PTR(ret);
-out:
+	rxrpc_put_call(call, rxrpc_call_put);
+	goto out;
+
+id_in_use:
+	ret = -EBADSLT;
 	write_unlock(&rx->call_lock);
+out:
+	rxrpc_service_prealloc(rx, GFP_KERNEL);
 	_leave(" = %d", ret);
 	return ERR_PTR(ret);
 }
@@ -564,6 +506,7 @@ out:
 int rxrpc_reject_call(struct rxrpc_sock *rx)
 {
 	struct rxrpc_call *call;
+	bool abort = false;
 	int ret;
 
 	_enter("");
@@ -572,15 +515,16 @@ int rxrpc_reject_call(struct rxrpc_sock *rx)
 
 	write_lock(&rx->call_lock);
 
-	ret = -ENODATA;
-	if (list_empty(&rx->acceptq)) {
+	if (list_empty(&rx->to_be_accepted)) {
 		write_unlock(&rx->call_lock);
-		_leave(" = -ENODATA");
 		return -ENODATA;
 	}
 
-	/* dequeue the first call and check it's still valid */
-	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
+	/* Dequeue the first call and check it's still valid.  We gain
+	 * responsibility for the queue's reference.
+	 */
+	call = list_entry(rx->to_be_accepted.next,
+			  struct rxrpc_call, accept_link);
 	list_del_init(&call->accept_link);
 	sk_acceptq_removed(&rx->sk);
 	rxrpc_see_call(call);
@@ -588,66 +532,28 @@ int rxrpc_reject_call(struct rxrpc_sock *rx)
 	write_lock_bh(&call->state_lock);
 	switch (call->state) {
 	case RXRPC_CALL_SERVER_ACCEPTING:
-		__rxrpc_set_call_completion(call, RXRPC_CALL_SERVER_BUSY,
-					    0, ECONNABORTED);
-		if (test_and_set_bit(RXRPC_CALL_EV_REJECT_BUSY, &call->events))
-			rxrpc_queue_call(call);
-		ret = 0;
-		break;
+		__rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, ECONNABORTED);
+		abort = true;
+		/* fall through */
 	case RXRPC_CALL_COMPLETE:
 		ret = call->error;
-		break;
+		goto out_discard;
 	default:
 		BUG();
 	}
 
+out_discard:
 	write_unlock_bh(&call->state_lock);
 	write_unlock(&rx->call_lock);
-	rxrpc_release_call(rx, call);
-	_leave(" = %d", ret);
-	return ret;
-}
-
-/**
- * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
- * @sock: The socket on which the impending call is waiting
- * @user_call_ID: The tag to attach to the call
- * @notify_rx: Where to send notifications instead of socket queue
- *
- * Allow a kernel service to accept an incoming call, assuming the incoming
- * call is still valid.  The caller should immediately trigger their own
- * notification as there must be data waiting.
- */
-struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock,
-					    unsigned long user_call_ID,
-					    rxrpc_notify_rx_t notify_rx)
-{
-	struct rxrpc_call *call;
-
-	_enter(",%lx", user_call_ID);
-	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID, notify_rx);
-	_leave(" = %p", call);
-	return call;
-}
-EXPORT_SYMBOL(rxrpc_kernel_accept_call);
-
-/**
- * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
- * @sock: The socket on which the impending call is waiting
- *
- * Allow a kernel service to reject an incoming call with a BUSY message,
- * assuming the incoming call is still valid.
- */
-int rxrpc_kernel_reject_call(struct socket *sock)
-{
-	int ret;
-
-	_enter("");
-	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
+	if (abort) {
+		rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put);
+	}
+	rxrpc_service_prealloc(rx, GFP_KERNEL);
 	_leave(" = %d", ret);
 	return ret;
 }
-EXPORT_SYMBOL(rxrpc_kernel_reject_call);
 
 /*
  * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls