From 18bfeba50dfd0c8ee420396f2570f16a0bdbd7de Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 23 Aug 2016 15:27:25 +0100 Subject: 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/conn_event.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) (limited to 'net/rxrpc/conn_event.c') 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; -- cgit v1.2.3-59-g8ed1b