From 18bfeba50dfd0c8ee420396f2570f16a0bdbd7de Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 23 Aug 2016 15:27:25 +0100 Subject: [PATCH] rxrpc: Perform terminal call ACK/ABORT retransmission from conn processor Perform terminal call ACK/ABORT retransmission in the connection processor rather than in the call processor. With this change, once last_call is set, no more incoming packets will be routed to the corresponding call or any earlier calls on that channel (call IDs must only increase on a channel on a connection). Further, if a packet's callNumber is before the last_call ID or a packet is aimed at successfully completed service call then that packet is discarded and ignored. Signed-off-by: David Howells --- net/rxrpc/ar-internal.h | 7 ++- net/rxrpc/conn_event.c | 113 ++++++++++++++++++++++++++++++++++++++++ net/rxrpc/conn_object.c | 10 +++- net/rxrpc/input.c | 31 ++++++++++- 4 files changed, 157 insertions(+), 4 deletions(-) diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index c779b50135f6..7296039c537a 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -295,7 +295,12 @@ struct rxrpc_connection { u32 call_id; /* ID of current call */ u32 call_counter; /* Call ID counter */ u32 last_call; /* ID of last call */ - u32 last_result; /* Result of last call (0/abort) */ + u8 last_type; /* Type of last packet */ + u16 last_service_id; + union { + u32 last_seq; + u32 last_abort; + }; } channels[RXRPC_MAXCALLS]; wait_queue_head_t channel_wq; /* queue to wait for channel to become available */ diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index c631d926f4db..c1c6b7f305d1 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -24,6 +24,113 @@ #include #include "ar-internal.h" +/* + * Retransmit terminal ACK or ABORT of the previous call. + */ +static void rxrpc_conn_retransmit(struct rxrpc_connection *conn, + struct sk_buff *skb) +{ + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + struct rxrpc_channel *chan; + struct msghdr msg; + struct kvec iov; + struct { + struct rxrpc_wire_header whdr; + union { + struct { + __be32 code; + } abort; + struct { + struct rxrpc_ackpacket ack; + struct rxrpc_ackinfo info; + }; + }; + } __attribute__((packed)) pkt; + size_t len; + u32 serial, mtu, call_id; + + _enter("%d", conn->debug_id); + + chan = &conn->channels[sp->hdr.cid & RXRPC_CHANNELMASK]; + + /* 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 (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; + + pkt.whdr.epoch = htonl(sp->hdr.epoch); + pkt.whdr.cid = htonl(sp->hdr.cid); + pkt.whdr.callNumber = htonl(sp->hdr.callNumber); + 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(chan->last_service_id); + + len = sizeof(pkt.whdr); + switch (chan->last_type) { + case RXRPC_PACKET_TYPE_ABORT: + pkt.abort.code = htonl(chan->last_abort); + len += sizeof(pkt.abort); + 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->priority); + pkt.ack.firstPacket = htonl(chan->last_seq); + pkt.ack.previousPacket = htonl(chan->last_seq - 1); + pkt.ack.serial = htonl(sp->hdr.serial); + pkt.ack.reason = RXRPC_ACK_DUPLICATE; + pkt.ack.nAcks = 0; + pkt.info.rxMTU = htonl(rxrpc_rx_mtu); + pkt.info.maxMTU = htonl(mtu); + pkt.info.rwind = htonl(rxrpc_rx_window_size); + pkt.info.jumbo_max = htonl(rxrpc_rx_jumbo_max); + len += sizeof(pkt.ack) + sizeof(pkt.info); + break; + } + + /* 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; + + iov.iov_base = &pkt; + iov.iov_len = len; + + 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->local_abort); + break; + case RXRPC_PACKET_TYPE_ACK: + _proto("Tx ACK %%%u [re]", serial); + break; + } + + kernel_sendmsg(conn->params.local->socket, &msg, &iov, 1, len); + _leave(""); + return; +} + /* * pass a connection-level abort onto all calls on that connection */ @@ -166,6 +273,12 @@ static int rxrpc_process_event(struct rxrpc_connection *conn, _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(conn, skb); + rxrpc_free_skb(skb); + return 0; + case RXRPC_PACKET_TYPE_ABORT: if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0) return -EPROTO; diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c index 743f0bb4aaa8..b4af37ebb112 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -166,7 +166,15 @@ void __rxrpc_disconnect_call(struct rxrpc_call *call) /* Save the result of the call so that we can repeat it if necessary * through the channel, whilst disposing of the actual call record. */ - chan->last_result = call->local_abort; + chan->last_service_id = call->service_id; + if (call->local_abort) { + chan->last_abort = call->local_abort; + chan->last_type = RXRPC_PACKET_TYPE_ABORT; + } else { + chan->last_seq = call->rx_data_eaten; + chan->last_type = RXRPC_PACKET_TYPE_ACK; + } + /* Sync with rxrpc_conn_retransmit(). */ smp_wmb(); chan->last_call = chan->call_id; chan->call_id = chan->call_counter; diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index 34f7431bf494..66cdeb56f44f 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -566,7 +566,8 @@ done: /* * post connection-level events to the connection - * - this includes challenges, responses and some aborts + * - 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) @@ -716,18 +717,44 @@ void rxrpc_data_ready(struct sock *sk) /* Connection-level packet */ _debug("CONN %p {%d}", conn, conn->debug_id); rxrpc_post_packet_to_conn(conn, skb); + goto out_unlock; } else { /* Call-bound packets are routed by connection channel. */ unsigned int channel = sp->hdr.cid & RXRPC_CHANNELMASK; struct rxrpc_channel *chan = &conn->channels[channel]; - struct rxrpc_call *call = rcu_dereference(chan->call); + struct rxrpc_call *call; + + /* Ignore really old calls */ + if (sp->hdr.callNumber < chan->last_call) + goto discard_unlock; + + if (sp->hdr.callNumber == chan->last_call) { + /* For the previous service call, if completed + * successfully, we discard all further packets. + */ + if (rxrpc_conn_is_service(call->conn) && + (chan->last_type == RXRPC_PACKET_TYPE_ACK || + sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)) + goto discard_unlock; + + /* But otherwise we need to retransmit the final packet + * from data cached in the connection record. + */ + rxrpc_post_packet_to_conn(conn, skb); + goto out_unlock; + } + call = rcu_dereference(chan->call); if (!call || atomic_read(&call->usage) == 0) goto cant_route_call; rxrpc_post_packet_to_call(call, skb); + goto out_unlock; } +discard_unlock: + rxrpc_free_skb(skb); +out_unlock: rcu_read_unlock(); out: return; -- 2.20.1