1 files changed, 499 insertions, 0 deletions

diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
new file mode 100644
index 000000000..aab069701
--- /dev/null
+++ b/net/rxrpc/conn_event.c
@@ -0,0 +1,499 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* connection-level event handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+/*
+ * Retransmit terminal ACK or ABORT of the previous call.
+ */
+static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
+				       struct sk_buff *skb,
+				       unsigned int channel)
+{
+	struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
+	struct rxrpc_channel *chan;
+	struct msghdr msg;
+	struct kvec iov[3];
+	struct {
+		struct rxrpc_wire_header whdr;
+		union {
+			__be32 abort_code;
+			struct rxrpc_ackpacket ack;
+		};
+	} __attribute__((packed)) pkt;
+	struct rxrpc_ackinfo ack_info;
+	size_t len;
+	int ret, ioc;
+	u32 serial, mtu, call_id, padding;
+
+	_enter("%d", conn->debug_id);
+
+	chan = &conn->channels[channel];
+
+	/* If the last call got moved on whilst we were waiting to run, just
+	 * ignore this packet.
+	 */
+	call_id = READ_ONCE(chan->last_call);
+	/* Sync with __rxrpc_disconnect_call() */
+	smp_rmb();
+	if (skb && call_id != sp->hdr.callNumber)
+		return;
+
+	msg.msg_name	= &conn->params.peer->srx.transport;
+	msg.msg_namelen	= conn->params.peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	iov[0].iov_base	= &pkt;
+	iov[0].iov_len	= sizeof(pkt.whdr);
+	iov[1].iov_base	= &padding;
+	iov[1].iov_len	= 3;
+	iov[2].iov_base	= &ack_info;
+	iov[2].iov_len	= sizeof(ack_info);
+
+	pkt.whdr.epoch		= htonl(conn->proto.epoch);
+	pkt.whdr.cid		= htonl(conn->proto.cid | channel);
+	pkt.whdr.callNumber	= htonl(call_id);
+	pkt.whdr.seq		= 0;
+	pkt.whdr.type		= chan->last_type;
+	pkt.whdr.flags		= conn->out_clientflag;
+	pkt.whdr.userStatus	= 0;
+	pkt.whdr.securityIndex	= conn->security_ix;
+	pkt.whdr._rsvd		= 0;
+	pkt.whdr.serviceId	= htons(conn->service_id);
+
+	len = sizeof(pkt.whdr);
+	switch (chan->last_type) {
+	case RXRPC_PACKET_TYPE_ABORT:
+		pkt.abort_code	= htonl(chan->last_abort);
+		iov[0].iov_len += sizeof(pkt.abort_code);
+		len += sizeof(pkt.abort_code);
+		ioc = 1;
+		break;
+
+	case RXRPC_PACKET_TYPE_ACK:
+		mtu = conn->params.peer->if_mtu;
+		mtu -= conn->params.peer->hdrsize;
+		pkt.ack.bufferSpace	= 0;
+		pkt.ack.maxSkew		= htons(skb ? skb->priority : 0);
+		pkt.ack.firstPacket	= htonl(chan->last_seq + 1);
+		pkt.ack.previousPacket	= htonl(chan->last_seq);
+		pkt.ack.serial		= htonl(skb ? sp->hdr.serial : 0);
+		pkt.ack.reason		= skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
+		pkt.ack.nAcks		= 0;
+		ack_info.rxMTU		= htonl(rxrpc_rx_mtu);
+		ack_info.maxMTU		= htonl(mtu);
+		ack_info.rwind		= htonl(rxrpc_rx_window_size);
+		ack_info.jumbo_max	= htonl(rxrpc_rx_jumbo_max);
+		pkt.whdr.flags		|= RXRPC_SLOW_START_OK;
+		padding			= 0;
+		iov[0].iov_len += sizeof(pkt.ack);
+		len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
+		ioc = 3;
+		break;
+
+	default:
+		return;
+	}
+
+	/* Resync with __rxrpc_disconnect_call() and check that the last call
+	 * didn't get advanced whilst we were filling out the packets.
+	 */
+	smp_rmb();
+	if (READ_ONCE(chan->last_call) != call_id)
+		return;
+
+	serial = atomic_inc_return(&conn->serial);
+	pkt.whdr.serial = htonl(serial);
+
+	switch (chan->last_type) {
+	case RXRPC_PACKET_TYPE_ABORT:
+		_proto("Tx ABORT %%%u { %d } [re]", serial, conn->abort_code);
+		break;
+	case RXRPC_PACKET_TYPE_ACK:
+		trace_rxrpc_tx_ack(chan->call_debug_id, serial,
+				   ntohl(pkt.ack.firstPacket),
+				   ntohl(pkt.ack.serial),
+				   pkt.ack.reason, 0);
+		_proto("Tx ACK %%%u [re]", serial);
+		break;
+	}
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+	if (ret < 0)
+		trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
+				    rxrpc_tx_point_call_final_resend);
+	else
+		trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
+				      rxrpc_tx_point_call_final_resend);
+
+	_leave("");
+}
+
+/*
+ * pass a connection-level abort onto all calls on that connection
+ */
+static void rxrpc_abort_calls(struct rxrpc_connection *conn,
+			      enum rxrpc_call_completion compl,
+			      rxrpc_serial_t serial)
+{
+	struct rxrpc_call *call;
+	int i;
+
+	_enter("{%d},%x", conn->debug_id, conn->abort_code);
+
+	spin_lock(&conn->bundle->channel_lock);
+
+	for (i = 0; i < RXRPC_MAXCALLS; i++) {
+		call = rcu_dereference_protected(
+			conn->channels[i].call,
+			lockdep_is_held(&conn->bundle->channel_lock));
+		if (call) {
+			if (compl == RXRPC_CALL_LOCALLY_ABORTED)
+				trace_rxrpc_abort(call->debug_id,
+						  "CON", call->cid,
+						  call->call_id, 0,
+						  conn->abort_code,
+						  conn->error);
+			else
+				trace_rxrpc_rx_abort(call, serial,
+						     conn->abort_code);
+			rxrpc_set_call_completion(call, compl,
+						  conn->abort_code,
+						  conn->error);
+		}
+	}
+
+	spin_unlock(&conn->bundle->channel_lock);
+	_leave("");
+}
+
+/*
+ * generate a connection-level abort
+ */
+static int rxrpc_abort_connection(struct rxrpc_connection *conn,
+				  int error, u32 abort_code)
+{
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	__be32 word;
+	size_t len;
+	u32 serial;
+	int ret;
+
+	_enter("%d,,%u,%u", conn->debug_id, error, abort_code);
+
+	/* generate a connection-level abort */
+	spin_lock_bh(&conn->state_lock);
+	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
+		spin_unlock_bh(&conn->state_lock);
+		_leave(" = 0 [already dead]");
+		return 0;
+	}
+
+	conn->error = error;
+	conn->abort_code = abort_code;
+	conn->state = RXRPC_CONN_LOCALLY_ABORTED;
+	set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+	spin_unlock_bh(&conn->state_lock);
+
+	msg.msg_name	= &conn->params.peer->srx.transport;
+	msg.msg_namelen	= conn->params.peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(conn->proto.epoch);
+	whdr.cid	= htonl(conn->proto.cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_ABORT;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
+
+	word		= htonl(conn->abort_code);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= &word;
+	iov[1].iov_len	= sizeof(word);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	serial = atomic_inc_return(&conn->serial);
+	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
+	whdr.serial = htonl(serial);
+	_proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
+
+	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_conn_abort);
+		_debug("sendmsg failed: %d", ret);
+		return -EAGAIN;
+	}
+
+	trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
+
+	conn->params.peer->last_tx_at = ktime_get_seconds();
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * mark a call as being on a now-secured channel
+ * - must be called with BH's disabled.
+ */
+static void rxrpc_call_is_secure(struct rxrpc_call *call)
+{
+	_enter("%p", call);
+	if (call) {
+		write_lock_bh(&call->state_lock);
+		if (call->state == RXRPC_CALL_SERVER_SECURING) {
+			call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
+			rxrpc_notify_socket(call);
+		}
+		write_unlock_bh(&call->state_lock);
+	}
+}
+
+/*
+ * connection-level Rx packet processor
+ */
+static int rxrpc_process_event(struct rxrpc_connection *conn,
+			       struct sk_buff *skb,
+			       u32 *_abort_code)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	__be32 wtmp;
+	u32 abort_code;
+	int loop, ret;
+
+	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
+		_leave(" = -ECONNABORTED [%u]", conn->state);
+		return -ECONNABORTED;
+	}
+
+	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_DATA:
+	case RXRPC_PACKET_TYPE_ACK:
+		rxrpc_conn_retransmit_call(conn, skb,
+					   sp->hdr.cid & RXRPC_CHANNELMASK);
+		return 0;
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		/* Just ignore BUSY packets for now. */
+		return 0;
+
+	case RXRPC_PACKET_TYPE_ABORT:
+		if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+				  &wtmp, sizeof(wtmp)) < 0) {
+			trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+					      tracepoint_string("bad_abort"));
+			return -EPROTO;
+		}
+		abort_code = ntohl(wtmp);
+		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
+
+		conn->error = -ECONNABORTED;
+		conn->abort_code = abort_code;
+		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
+		set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
+		return -ECONNABORTED;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		return conn->security->respond_to_challenge(conn, skb,
+							    _abort_code);
+
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		ret = conn->security->verify_response(conn, skb, _abort_code);
+		if (ret < 0)
+			return ret;
+
+		ret = conn->security->init_connection_security(
+			conn, conn->params.key->payload.data[0]);
+		if (ret < 0)
+			return ret;
+
+		spin_lock(&conn->bundle->channel_lock);
+		spin_lock_bh(&conn->state_lock);
+
+		if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
+			conn->state = RXRPC_CONN_SERVICE;
+			spin_unlock_bh(&conn->state_lock);
+			for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
+				rxrpc_call_is_secure(
+					rcu_dereference_protected(
+						conn->channels[loop].call,
+						lockdep_is_held(&conn->bundle->channel_lock)));
+		} else {
+			spin_unlock_bh(&conn->state_lock);
+		}
+
+		spin_unlock(&conn->bundle->channel_lock);
+		return 0;
+
+	default:
+		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
+				      tracepoint_string("bad_conn_pkt"));
+		return -EPROTO;
+	}
+}
+
+/*
+ * set up security and issue a challenge
+ */
+static void rxrpc_secure_connection(struct rxrpc_connection *conn)
+{
+	u32 abort_code;
+	int ret;
+
+	_enter("{%d}", conn->debug_id);
+
+	ASSERT(conn->security_ix != 0);
+
+	if (conn->security->issue_challenge(conn) < 0) {
+		abort_code = RX_CALL_DEAD;
+		ret = -ENOMEM;
+		goto abort;
+	}
+
+	_leave("");
+	return;
+
+abort:
+	_debug("abort %d, %d", ret, abort_code);
+	rxrpc_abort_connection(conn, ret, abort_code);
+	_leave(" [aborted]");
+}
+
+/*
+ * Process delayed final ACKs that we haven't subsumed into a subsequent call.
+ */
+void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
+{
+	unsigned long j = jiffies, next_j;
+	unsigned int channel;
+	bool set;
+
+again:
+	next_j = j + LONG_MAX;
+	set = false;
+	for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
+		struct rxrpc_channel *chan = &conn->channels[channel];
+		unsigned long ack_at;
+
+		if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
+			continue;
+
+		smp_rmb(); /* vs rxrpc_disconnect_client_call */
+		ack_at = READ_ONCE(chan->final_ack_at);
+
+		if (time_before(j, ack_at) && !force) {
+			if (time_before(ack_at, next_j)) {
+				next_j = ack_at;
+				set = true;
+			}
+			continue;
+		}
+
+		if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
+				       &conn->flags))
+			rxrpc_conn_retransmit_call(conn, NULL, channel);
+	}
+
+	j = jiffies;
+	if (time_before_eq(next_j, j))
+		goto again;
+	if (set)
+		rxrpc_reduce_conn_timer(conn, next_j);
+}
+
+/*
+ * connection-level event processor
+ */
+static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
+{
+	struct sk_buff *skb;
+	u32 abort_code = RX_PROTOCOL_ERROR;
+	int ret;
+
+	if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
+		rxrpc_secure_connection(conn);
+
+	/* Process delayed ACKs whose time has come. */
+	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+		rxrpc_process_delayed_final_acks(conn, false);
+
+	/* go through the conn-level event packets, releasing the ref on this
+	 * connection that each one has when we've finished with it */
+	while ((skb = skb_dequeue(&conn->rx_queue))) {
+		rxrpc_see_skb(skb, rxrpc_skb_seen);
+		ret = rxrpc_process_event(conn, skb, &abort_code);
+		switch (ret) {
+		case -EPROTO:
+		case -EKEYEXPIRED:
+		case -EKEYREJECTED:
+			goto protocol_error;
+		case -ENOMEM:
+		case -EAGAIN:
+			goto requeue_and_leave;
+		case -ECONNABORTED:
+		default:
+			rxrpc_free_skb(skb, rxrpc_skb_freed);
+			break;
+		}
+	}
+
+	return;
+
+requeue_and_leave:
+	skb_queue_head(&conn->rx_queue, skb);
+	return;
+
+protocol_error:
+	if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
+		goto requeue_and_leave;
+	rxrpc_free_skb(skb, rxrpc_skb_freed);
+	return;
+}
+
+void rxrpc_process_connection(struct work_struct *work)
+{
+	struct rxrpc_connection *conn =
+		container_of(work, struct rxrpc_connection, processor);
+
+	rxrpc_see_connection(conn);
+
+	if (__rxrpc_use_local(conn->params.local)) {
+		rxrpc_do_process_connection(conn);
+		rxrpc_unuse_local(conn->params.local);
+	}
+
+	rxrpc_put_connection(conn);
+	_leave("");
+	return;
+}