1 files changed, 560 insertions, 0 deletions

diff --git a/net/rxrpc/io_thread.c b/net/rxrpc/io_thread.c
new file mode 100644
index 0000000000..4a3a08a0e2
--- /dev/null
+++ b/net/rxrpc/io_thread.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC packet reception
+ *
+ * Copyright (C) 2007, 2016, 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "ar-internal.h"
+
+static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
+				      struct sockaddr_rxrpc *peer_srx,
+				      struct sk_buff *skb);
+
+/*
+ * handle data received on the local endpoint
+ * - may be called in interrupt context
+ *
+ * [!] Note that as this is called from the encap_rcv hook, the socket is not
+ * held locked by the caller and nothing prevents sk_user_data on the UDP from
+ * being cleared in the middle of processing this function.
+ *
+ * Called with the RCU read lock held from the IP layer via UDP.
+ */
+int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb)
+{
+	struct sk_buff_head *rx_queue;
+	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
+
+	if (unlikely(!local)) {
+		kfree_skb(skb);
+		return 0;
+	}
+	if (skb->tstamp == 0)
+		skb->tstamp = ktime_get_real();
+
+	skb->mark = RXRPC_SKB_MARK_PACKET;
+	rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv);
+	rx_queue = &local->rx_queue;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	if (rxrpc_inject_rx_delay ||
+	    !skb_queue_empty(&local->rx_delay_queue)) {
+		skb->tstamp = ktime_add_ms(skb->tstamp, rxrpc_inject_rx_delay);
+		rx_queue = &local->rx_delay_queue;
+	}
+#endif
+
+	skb_queue_tail(rx_queue, skb);
+	rxrpc_wake_up_io_thread(local);
+	return 0;
+}
+
+/*
+ * Handle an error received on the local endpoint.
+ */
+void rxrpc_error_report(struct sock *sk)
+{
+	struct rxrpc_local *local;
+	struct sk_buff *skb;
+
+	rcu_read_lock();
+	local = rcu_dereference_sk_user_data(sk);
+	if (unlikely(!local)) {
+		rcu_read_unlock();
+		return;
+	}
+
+	while ((skb = skb_dequeue(&sk->sk_error_queue))) {
+		skb->mark = RXRPC_SKB_MARK_ERROR;
+		rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
+		skb_queue_tail(&local->rx_queue, skb);
+	}
+
+	rxrpc_wake_up_io_thread(local);
+	rcu_read_unlock();
+}
+
+/*
+ * Directly produce an abort from a packet.
+ */
+bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			s32 abort_code, int err)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  abort_code, err);
+	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+	skb->priority = abort_code;
+	return false;
+}
+
+static bool rxrpc_bad_message(struct sk_buff *skb, enum rxrpc_abort_reason why)
+{
+	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EBADMSG);
+}
+
+#define just_discard true
+
+/*
+ * Process event packets targeted at a local endpoint.
+ */
+static bool rxrpc_input_version(struct rxrpc_local *local, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	char v;
+
+	_enter("");
+
+	rxrpc_see_skb(skb, rxrpc_skb_see_version);
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), &v, 1) >= 0) {
+		if (v == 0)
+			rxrpc_send_version_request(local, &sp->hdr, skb);
+	}
+
+	return true;
+}
+
+/*
+ * Extract the wire header from a packet and translate the byte order.
+ */
+static bool rxrpc_extract_header(struct rxrpc_skb_priv *sp,
+				 struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+
+	/* dig out the RxRPC connection details */
+	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
+		return rxrpc_bad_message(skb, rxrpc_badmsg_short_hdr);
+
+	memset(sp, 0, sizeof(*sp));
+	sp->hdr.epoch		= ntohl(whdr.epoch);
+	sp->hdr.cid		= ntohl(whdr.cid);
+	sp->hdr.callNumber	= ntohl(whdr.callNumber);
+	sp->hdr.seq		= ntohl(whdr.seq);
+	sp->hdr.serial		= ntohl(whdr.serial);
+	sp->hdr.flags		= whdr.flags;
+	sp->hdr.type		= whdr.type;
+	sp->hdr.userStatus	= whdr.userStatus;
+	sp->hdr.securityIndex	= whdr.securityIndex;
+	sp->hdr._rsvd		= ntohs(whdr._rsvd);
+	sp->hdr.serviceId	= ntohs(whdr.serviceId);
+	return true;
+}
+
+/*
+ * Extract the abort code from an ABORT packet and stash it in skb->priority.
+ */
+static bool rxrpc_extract_abort(struct sk_buff *skb)
+{
+	__be32 wtmp;
+
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  &wtmp, sizeof(wtmp)) < 0)
+		return false;
+	skb->priority = ntohl(wtmp);
+	return true;
+}
+
+/*
+ * Process packets received on the local endpoint
+ */
+static bool rxrpc_input_packet(struct rxrpc_local *local, struct sk_buff **_skb)
+{
+	struct rxrpc_connection *conn;
+	struct sockaddr_rxrpc peer_srx;
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_peer *peer = NULL;
+	struct sk_buff *skb = *_skb;
+	bool ret = false;
+
+	skb_pull(skb, sizeof(struct udphdr));
+
+	sp = rxrpc_skb(skb);
+
+	/* dig out the RxRPC connection details */
+	if (!rxrpc_extract_header(sp, skb))
+		return just_discard;
+
+	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+		static int lose;
+		if ((lose++ & 7) == 7) {
+			trace_rxrpc_rx_lose(sp);
+			return just_discard;
+		}
+	}
+
+	trace_rxrpc_rx_packet(sp);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_VERSION:
+		if (rxrpc_to_client(sp))
+			return just_discard;
+		return rxrpc_input_version(local, skb);
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		if (rxrpc_to_server(sp))
+			return just_discard;
+		fallthrough;
+	case RXRPC_PACKET_TYPE_ACK:
+	case RXRPC_PACKET_TYPE_ACKALL:
+		if (sp->hdr.callNumber == 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
+		break;
+	case RXRPC_PACKET_TYPE_ABORT:
+		if (!rxrpc_extract_abort(skb))
+			return just_discard; /* Just discard if malformed */
+		break;
+
+	case RXRPC_PACKET_TYPE_DATA:
+		if (sp->hdr.callNumber == 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
+		if (sp->hdr.seq == 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_seq);
+
+		/* Unshare the packet so that it can be modified for in-place
+		 * decryption.
+		 */
+		if (sp->hdr.securityIndex != 0) {
+			skb = skb_unshare(skb, GFP_ATOMIC);
+			if (!skb) {
+				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare_nomem);
+				*_skb = NULL;
+				return just_discard;
+			}
+
+			if (skb != *_skb) {
+				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare);
+				*_skb = skb;
+				rxrpc_new_skb(skb, rxrpc_skb_new_unshared);
+				sp = rxrpc_skb(skb);
+			}
+		}
+		break;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		if (rxrpc_to_server(sp))
+			return just_discard;
+		break;
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		if (rxrpc_to_client(sp))
+			return just_discard;
+		break;
+
+		/* Packet types 9-11 should just be ignored. */
+	case RXRPC_PACKET_TYPE_PARAMS:
+	case RXRPC_PACKET_TYPE_10:
+	case RXRPC_PACKET_TYPE_11:
+		return just_discard;
+
+	default:
+		return rxrpc_bad_message(skb, rxrpc_badmsg_unsupported_packet);
+	}
+
+	if (sp->hdr.serviceId == 0)
+		return rxrpc_bad_message(skb, rxrpc_badmsg_zero_service);
+
+	if (WARN_ON_ONCE(rxrpc_extract_addr_from_skb(&peer_srx, skb) < 0))
+		return just_discard; /* Unsupported address type. */
+
+	if (peer_srx.transport.family != local->srx.transport.family &&
+	    (peer_srx.transport.family == AF_INET &&
+	     local->srx.transport.family != AF_INET6)) {
+		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
+				    peer_srx.transport.family,
+				    local->srx.transport.family);
+		return just_discard; /* Wrong address type. */
+	}
+
+	if (rxrpc_to_client(sp)) {
+		rcu_read_lock();
+		conn = rxrpc_find_client_connection_rcu(local, &peer_srx, skb);
+		conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
+		rcu_read_unlock();
+		if (!conn)
+			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_conn);
+
+		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
+		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
+		return ret;
+	}
+
+	/* We need to look up service connections by the full protocol
+	 * parameter set.  We look up the peer first as an intermediate step
+	 * and then the connection from the peer's tree.
+	 */
+	rcu_read_lock();
+
+	peer = rxrpc_lookup_peer_rcu(local, &peer_srx);
+	if (!peer) {
+		rcu_read_unlock();
+		return rxrpc_new_incoming_call(local, NULL, NULL, &peer_srx, skb);
+	}
+
+	conn = rxrpc_find_service_conn_rcu(peer, skb);
+	conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
+	if (conn) {
+		rcu_read_unlock();
+		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
+		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
+		return ret;
+	}
+
+	peer = rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input);
+	rcu_read_unlock();
+
+	ret = rxrpc_new_incoming_call(local, peer, NULL, &peer_srx, skb);
+	rxrpc_put_peer(peer, rxrpc_peer_put_input);
+	return ret;
+}
+
+/*
+ * Deal with a packet that's associated with an extant connection.
+ */
+static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
+				      struct sockaddr_rxrpc *peer_srx,
+				      struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_channel *chan;
+	struct rxrpc_call *call = NULL;
+	unsigned int channel;
+	bool ret;
+
+	if (sp->hdr.securityIndex != conn->security_ix)
+		return rxrpc_direct_abort(skb, rxrpc_eproto_wrong_security,
+					  RXKADINCONSISTENCY, -EBADMSG);
+
+	if (sp->hdr.serviceId != conn->service_id) {
+		int old_id;
+
+		if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
+			return rxrpc_protocol_error(skb, rxrpc_eproto_reupgrade);
+
+		old_id = cmpxchg(&conn->service_id, conn->orig_service_id,
+				 sp->hdr.serviceId);
+		if (old_id != conn->orig_service_id &&
+		    old_id != sp->hdr.serviceId)
+			return rxrpc_protocol_error(skb, rxrpc_eproto_bad_upgrade);
+	}
+
+	if (after(sp->hdr.serial, conn->hi_serial))
+		conn->hi_serial = sp->hdr.serial;
+
+	/* It's a connection-level packet if the call number is 0. */
+	if (sp->hdr.callNumber == 0)
+		return rxrpc_input_conn_packet(conn, skb);
+
+	/* Call-bound packets are routed by connection channel. */
+	channel = sp->hdr.cid & RXRPC_CHANNELMASK;
+	chan = &conn->channels[channel];
+
+	/* Ignore really old calls */
+	if (sp->hdr.callNumber < chan->last_call)
+		return just_discard;
+
+	if (sp->hdr.callNumber == chan->last_call) {
+		if (chan->call ||
+		    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+			return just_discard;
+
+		/* For the previous service call, if completed successfully, we
+		 * discard all further packets.
+		 */
+		if (rxrpc_conn_is_service(conn) &&
+		    chan->last_type == RXRPC_PACKET_TYPE_ACK)
+			return just_discard;
+
+		/* But otherwise we need to retransmit the final packet from
+		 * data cached in the connection record.
+		 */
+		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
+			trace_rxrpc_rx_data(chan->call_debug_id,
+					    sp->hdr.seq,
+					    sp->hdr.serial,
+					    sp->hdr.flags);
+		rxrpc_conn_retransmit_call(conn, skb, channel);
+		return just_discard;
+	}
+
+	call = rxrpc_try_get_call(chan->call, rxrpc_call_get_input);
+
+	if (sp->hdr.callNumber > chan->call_id) {
+		if (rxrpc_to_client(sp)) {
+			rxrpc_put_call(call, rxrpc_call_put_input);
+			return rxrpc_protocol_error(skb,
+						    rxrpc_eproto_unexpected_implicit_end);
+		}
+
+		if (call) {
+			rxrpc_implicit_end_call(call, skb);
+			rxrpc_put_call(call, rxrpc_call_put_input);
+			call = NULL;
+		}
+	}
+
+	if (!call) {
+		if (rxrpc_to_client(sp))
+			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_call);
+		return rxrpc_new_incoming_call(conn->local, conn->peer, conn,
+					       peer_srx, skb);
+	}
+
+	ret = rxrpc_input_call_event(call, skb);
+	rxrpc_put_call(call, rxrpc_call_put_input);
+	return ret;
+}
+
+/*
+ * I/O and event handling thread.
+ */
+int rxrpc_io_thread(void *data)
+{
+	struct rxrpc_connection *conn;
+	struct sk_buff_head rx_queue;
+	struct rxrpc_local *local = data;
+	struct rxrpc_call *call;
+	struct sk_buff *skb;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	ktime_t now;
+#endif
+	bool should_stop;
+
+	complete(&local->io_thread_ready);
+
+	skb_queue_head_init(&rx_queue);
+
+	set_user_nice(current, MIN_NICE);
+
+	for (;;) {
+		rxrpc_inc_stat(local->rxnet, stat_io_loop);
+
+		/* Deal with connections that want immediate attention. */
+		conn = list_first_entry_or_null(&local->conn_attend_q,
+						struct rxrpc_connection,
+						attend_link);
+		if (conn) {
+			spin_lock_bh(&local->lock);
+			list_del_init(&conn->attend_link);
+			spin_unlock_bh(&local->lock);
+
+			rxrpc_input_conn_event(conn, NULL);
+			rxrpc_put_connection(conn, rxrpc_conn_put_poke);
+			continue;
+		}
+
+		if (test_and_clear_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
+				       &local->client_conn_flags))
+			rxrpc_discard_expired_client_conns(local);
+
+		/* Deal with calls that want immediate attention. */
+		if ((call = list_first_entry_or_null(&local->call_attend_q,
+						     struct rxrpc_call,
+						     attend_link))) {
+			spin_lock_bh(&local->lock);
+			list_del_init(&call->attend_link);
+			spin_unlock_bh(&local->lock);
+
+			trace_rxrpc_call_poked(call);
+			rxrpc_input_call_event(call, NULL);
+			rxrpc_put_call(call, rxrpc_call_put_poke);
+			continue;
+		}
+
+		if (!list_empty(&local->new_client_calls))
+			rxrpc_connect_client_calls(local);
+
+		/* Process received packets and errors. */
+		if ((skb = __skb_dequeue(&rx_queue))) {
+			struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+			switch (skb->mark) {
+			case RXRPC_SKB_MARK_PACKET:
+				skb->priority = 0;
+				if (!rxrpc_input_packet(local, &skb))
+					rxrpc_reject_packet(local, skb);
+				trace_rxrpc_rx_done(skb->mark, skb->priority);
+				rxrpc_free_skb(skb, rxrpc_skb_put_input);
+				break;
+			case RXRPC_SKB_MARK_ERROR:
+				rxrpc_input_error(local, skb);
+				rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
+				break;
+			case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
+				rxrpc_input_conn_event(sp->conn, skb);
+				rxrpc_put_connection(sp->conn, rxrpc_conn_put_poke);
+				rxrpc_free_skb(skb, rxrpc_skb_put_conn_secured);
+				break;
+			default:
+				WARN_ON_ONCE(1);
+				rxrpc_free_skb(skb, rxrpc_skb_put_unknown);
+				break;
+			}
+			continue;
+		}
+
+		/* Inject a delay into packets if requested. */
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+		now = ktime_get_real();
+		while ((skb = skb_peek(&local->rx_delay_queue))) {
+			if (ktime_before(now, skb->tstamp))
+				break;
+			skb = skb_dequeue(&local->rx_delay_queue);
+			skb_queue_tail(&local->rx_queue, skb);
+		}
+#endif
+
+		if (!skb_queue_empty(&local->rx_queue)) {
+			spin_lock_irq(&local->rx_queue.lock);
+			skb_queue_splice_tail_init(&local->rx_queue, &rx_queue);
+			spin_unlock_irq(&local->rx_queue.lock);
+			continue;
+		}
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		should_stop = kthread_should_stop();
+		if (!skb_queue_empty(&local->rx_queue) ||
+		    !list_empty(&local->call_attend_q) ||
+		    !list_empty(&local->conn_attend_q) ||
+		    !list_empty(&local->new_client_calls) ||
+		    test_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
+			     &local->client_conn_flags)) {
+			__set_current_state(TASK_RUNNING);
+			continue;
+		}
+
+		if (should_stop)
+			break;
+
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+		skb = skb_peek(&local->rx_delay_queue);
+		if (skb) {
+			unsigned long timeout;
+			ktime_t tstamp = skb->tstamp;
+			ktime_t now = ktime_get_real();
+			s64 delay_ns = ktime_to_ns(ktime_sub(tstamp, now));
+
+			if (delay_ns <= 0) {
+				__set_current_state(TASK_RUNNING);
+				continue;
+			}
+
+			timeout = nsecs_to_jiffies(delay_ns);
+			timeout = max(timeout, 1UL);
+			schedule_timeout(timeout);
+			__set_current_state(TASK_RUNNING);
+			continue;
+		}
+#endif
+
+		schedule();
+	}
+
+	__set_current_state(TASK_RUNNING);
+	rxrpc_see_local(local, rxrpc_local_stop);
+	rxrpc_destroy_local(local);
+	local->io_thread = NULL;
+	rxrpc_see_local(local, rxrpc_local_stopped);
+	return 0;
+}