From 96b2d69b43a075a38df600597133f17d28525f24 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 23 Jan 2020 13:01:33 +0000 Subject: rxrpc: Split the receive code Split the code that handles packet reception in softirq mode as a prelude to moving all the packet processing beyond routing to the appropriate call and setting up of a new call out into process context. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- net/rxrpc/input.c | 372 +----------------------------------------------------- 1 file changed, 6 insertions(+), 366 deletions(-) (limited to 'net/rxrpc/input.c') diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index ab8b7a1be935..f4f6f3c62d03 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-or-later -/* RxRPC packet reception +/* Processing of received RxRPC packets * - * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ @@ -1029,7 +1029,7 @@ static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) /* * Process an incoming call packet. */ -static void rxrpc_input_call_packet(struct rxrpc_call *call, +void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb) { struct rxrpc_skb_priv *sp = rxrpc_skb(skb); @@ -1086,9 +1086,9 @@ no_free: * * TODO: If callNumber > call_id + 1, renegotiate security. */ -static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, - struct rxrpc_connection *conn, - struct rxrpc_call *call) +void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, + struct rxrpc_connection *conn, + struct rxrpc_call *call) { switch (READ_ONCE(call->state)) { case RXRPC_CALL_SERVER_AWAIT_ACK: @@ -1109,363 +1109,3 @@ static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx, __rxrpc_disconnect_call(conn, call); spin_unlock(&rx->incoming_lock); } - -/* - * post connection-level events to the connection - * - this includes challenges, responses, some aborts and call terminal packet - * retransmission. - */ -static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, - struct sk_buff *skb) -{ - _enter("%p,%p", conn, skb); - - skb_queue_tail(&conn->rx_queue, skb); - rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work); -} - -/* - * post endpoint-level events to the local endpoint - * - this includes debug and version messages - */ -static void rxrpc_post_packet_to_local(struct rxrpc_local *local, - struct sk_buff *skb) -{ - _enter("%p,%p", local, skb); - - if (rxrpc_get_local_maybe(local, rxrpc_local_get_queue)) { - skb_queue_tail(&local->event_queue, skb); - rxrpc_queue_local(local); - } else { - rxrpc_free_skb(skb, rxrpc_skb_put_input); - } -} - -/* - * put a packet up for transport-level abort - */ -static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) -{ - if (rxrpc_get_local_maybe(local, rxrpc_local_get_queue)) { - skb_queue_tail(&local->reject_queue, skb); - rxrpc_queue_local(local); - } else { - rxrpc_free_skb(skb, rxrpc_skb_put_input); - } -} - -/* - * Extract the wire header from a packet and translate the byte order. - */ -static noinline -int 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) { - trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, - tracepoint_string("bad_hdr")); - return -EBADMSG; - } - - 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 0; -} - -/* - * 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; -} - -/* - * 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_input_packet(struct sock *udp_sk, struct sk_buff *skb) -{ - struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); - struct rxrpc_connection *conn; - struct rxrpc_channel *chan; - struct rxrpc_call *call = NULL; - struct rxrpc_skb_priv *sp; - struct rxrpc_peer *peer = NULL; - struct rxrpc_sock *rx = NULL; - unsigned int channel; - - _enter("%p", udp_sk); - - if (unlikely(!local)) { - kfree_skb(skb); - return 0; - } - if (skb->tstamp == 0) - skb->tstamp = ktime_get_real(); - - rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv); - - skb_pull(skb, sizeof(struct udphdr)); - - /* The UDP protocol already released all skb resources; - * we are free to add our own data there. - */ - sp = rxrpc_skb(skb); - - /* dig out the RxRPC connection details */ - if (rxrpc_extract_header(sp, skb) < 0) - goto bad_message; - - if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { - static int lose; - if ((lose++ & 7) == 7) { - trace_rxrpc_rx_lose(sp); - rxrpc_free_skb(skb, rxrpc_skb_put_lose); - return 0; - } - } - - if (skb->tstamp == 0) - skb->tstamp = ktime_get_real(); - trace_rxrpc_rx_packet(sp); - - switch (sp->hdr.type) { - case RXRPC_PACKET_TYPE_VERSION: - if (rxrpc_to_client(sp)) - goto discard; - rxrpc_post_packet_to_local(local, skb); - goto out; - - case RXRPC_PACKET_TYPE_BUSY: - if (rxrpc_to_server(sp)) - goto discard; - fallthrough; - case RXRPC_PACKET_TYPE_ACK: - case RXRPC_PACKET_TYPE_ACKALL: - if (sp->hdr.callNumber == 0) - goto bad_message; - break; - case RXRPC_PACKET_TYPE_ABORT: - if (!rxrpc_extract_abort(skb)) - return true; /* Just discard if malformed */ - break; - - case RXRPC_PACKET_TYPE_DATA: - if (sp->hdr.callNumber == 0 || - sp->hdr.seq == 0) - goto bad_message; - - /* Unshare the packet so that it can be modified for in-place - * decryption. - */ - if (sp->hdr.securityIndex != 0) { - struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC); - if (!nskb) { - rxrpc_eaten_skb(skb, rxrpc_skb_eaten_by_unshare_nomem); - goto out; - } - - if (nskb != skb) { - rxrpc_eaten_skb(skb, rxrpc_skb_eaten_by_unshare); - skb = nskb; - rxrpc_new_skb(skb, rxrpc_skb_new_unshared); - sp = rxrpc_skb(skb); - } - } - break; - - case RXRPC_PACKET_TYPE_CHALLENGE: - if (rxrpc_to_server(sp)) - goto discard; - break; - case RXRPC_PACKET_TYPE_RESPONSE: - if (rxrpc_to_client(sp)) - goto 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: - goto discard; - - default: - goto bad_message; - } - - if (sp->hdr.serviceId == 0) - goto bad_message; - - if (rxrpc_to_server(sp)) { - /* Weed out packets to services we're not offering. Packets - * that would begin a call are explicitly rejected and the rest - * are just discarded. - */ - rx = rcu_dereference(local->service); - if (!rx || (sp->hdr.serviceId != rx->srx.srx_service && - sp->hdr.serviceId != rx->second_service)) { - if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA && - sp->hdr.seq == 1) - goto unsupported_service; - goto discard; - } - } - - conn = rxrpc_find_connection_rcu(local, skb, &peer); - if (conn) { - if (sp->hdr.securityIndex != conn->security_ix) - goto wrong_security; - - if (sp->hdr.serviceId != conn->service_id) { - int old_id; - - if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) - goto 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) - goto reupgrade; - } - - if (sp->hdr.callNumber == 0) { - /* Connection-level packet */ - _debug("CONN %p {%d}", conn, conn->debug_id); - rxrpc_post_packet_to_conn(conn, skb); - goto out; - } - - if ((int)sp->hdr.serial - (int)conn->hi_serial > 0) - conn->hi_serial = sp->hdr.serial; - - /* 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) - goto discard; - - if (sp->hdr.callNumber == chan->last_call) { - if (chan->call || - sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) - goto 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) - goto 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_post_packet_to_conn(conn, skb); - goto out; - } - - call = rcu_dereference(chan->call); - - if (sp->hdr.callNumber > chan->call_id) { - if (rxrpc_to_client(sp)) - goto reject_packet; - if (call) - rxrpc_input_implicit_end_call(rx, conn, call); - call = NULL; - } - - if (call) { - if (sp->hdr.serviceId != call->service_id) - call->service_id = sp->hdr.serviceId; - if ((int)sp->hdr.serial - (int)call->rx_serial > 0) - call->rx_serial = sp->hdr.serial; - if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags)) - set_bit(RXRPC_CALL_RX_HEARD, &call->flags); - } - } - - if (!call || refcount_read(&call->ref) == 0) { - if (rxrpc_to_client(sp) || - sp->hdr.type != RXRPC_PACKET_TYPE_DATA) - goto bad_message; - if (sp->hdr.seq != 1) - goto discard; - call = rxrpc_new_incoming_call(local, rx, skb); - if (!call) - goto reject_packet; - } - - /* Process a call packet; this either discards or passes on the ref - * elsewhere. - */ - rxrpc_input_call_packet(call, skb); - goto out; - -discard: - rxrpc_free_skb(skb, rxrpc_skb_put_input); -out: - trace_rxrpc_rx_done(0, 0); - return 0; - -wrong_security: - trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, - RXKADINCONSISTENCY, EBADMSG); - skb->priority = RXKADINCONSISTENCY; - goto post_abort; - -unsupported_service: - trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, - RX_INVALID_OPERATION, EOPNOTSUPP); - skb->priority = RX_INVALID_OPERATION; - goto post_abort; - -reupgrade: - trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, - RX_PROTOCOL_ERROR, EBADMSG); - goto protocol_error; - -bad_message: - trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, - RX_PROTOCOL_ERROR, EBADMSG); -protocol_error: - skb->priority = RX_PROTOCOL_ERROR; -post_abort: - skb->mark = RXRPC_SKB_MARK_REJECT_ABORT; -reject_packet: - trace_rxrpc_rx_done(skb->mark, skb->priority); - rxrpc_reject_packet(local, skb); - _leave(" [badmsg]"); - return 0; -} -- cgit