459 lines
12 KiB
C
459 lines
12 KiB
C
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/* RxRPC packet transmission
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/net.h>
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#include <linux/gfp.h>
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#include <linux/skbuff.h>
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#include <linux/export.h>
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#include <net/sock.h>
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#include <net/af_rxrpc.h>
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#include "ar-internal.h"
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struct rxrpc_ack_buffer {
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struct rxrpc_wire_header whdr;
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struct rxrpc_ackpacket ack;
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u8 acks[255];
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u8 pad[3];
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struct rxrpc_ackinfo ackinfo;
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};
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struct rxrpc_abort_buffer {
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struct rxrpc_wire_header whdr;
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__be32 abort_code;
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};
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/*
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* Fill out an ACK packet.
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*/
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static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
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struct rxrpc_ack_buffer *pkt,
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rxrpc_seq_t *_hard_ack,
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rxrpc_seq_t *_top,
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u8 reason)
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{
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rxrpc_serial_t serial;
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rxrpc_seq_t hard_ack, top, seq;
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int ix;
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u32 mtu, jmax;
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u8 *ackp = pkt->acks;
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/* Barrier against rxrpc_input_data(). */
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serial = call->ackr_serial;
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hard_ack = READ_ONCE(call->rx_hard_ack);
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top = smp_load_acquire(&call->rx_top);
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*_hard_ack = hard_ack;
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*_top = top;
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pkt->ack.bufferSpace = htons(8);
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pkt->ack.maxSkew = htons(call->ackr_skew);
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pkt->ack.firstPacket = htonl(hard_ack + 1);
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pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
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pkt->ack.serial = htonl(serial);
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pkt->ack.reason = reason;
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pkt->ack.nAcks = top - hard_ack;
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if (reason == RXRPC_ACK_PING)
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pkt->whdr.flags |= RXRPC_REQUEST_ACK;
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if (after(top, hard_ack)) {
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seq = hard_ack + 1;
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do {
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ix = seq & RXRPC_RXTX_BUFF_MASK;
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if (call->rxtx_buffer[ix])
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*ackp++ = RXRPC_ACK_TYPE_ACK;
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else
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*ackp++ = RXRPC_ACK_TYPE_NACK;
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seq++;
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} while (before_eq(seq, top));
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}
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mtu = call->conn->params.peer->if_mtu;
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mtu -= call->conn->params.peer->hdrsize;
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jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
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pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
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pkt->ackinfo.maxMTU = htonl(mtu);
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pkt->ackinfo.rwind = htonl(call->rx_winsize);
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pkt->ackinfo.jumbo_max = htonl(jmax);
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*ackp++ = 0;
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*ackp++ = 0;
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*ackp++ = 0;
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return top - hard_ack + 3;
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}
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/*
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* Send an ACK call packet.
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*/
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int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
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{
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struct rxrpc_connection *conn;
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struct rxrpc_ack_buffer *pkt;
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struct msghdr msg;
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struct kvec iov[2];
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rxrpc_serial_t serial;
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rxrpc_seq_t hard_ack, top;
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size_t len, n;
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int ret;
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u8 reason;
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if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
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return -ECONNRESET;
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pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
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if (!pkt)
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return -ENOMEM;
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conn = call->conn;
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msg.msg_name = &call->peer->srx.transport;
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msg.msg_namelen = call->peer->srx.transport_len;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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msg.msg_flags = 0;
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pkt->whdr.epoch = htonl(conn->proto.epoch);
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pkt->whdr.cid = htonl(call->cid);
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pkt->whdr.callNumber = htonl(call->call_id);
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pkt->whdr.seq = 0;
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pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
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pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
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pkt->whdr.userStatus = 0;
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pkt->whdr.securityIndex = call->security_ix;
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pkt->whdr._rsvd = 0;
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pkt->whdr.serviceId = htons(call->service_id);
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spin_lock_bh(&call->lock);
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if (ping) {
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reason = RXRPC_ACK_PING;
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} else {
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reason = call->ackr_reason;
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if (!call->ackr_reason) {
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spin_unlock_bh(&call->lock);
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ret = 0;
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goto out;
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}
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call->ackr_reason = 0;
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}
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n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top, reason);
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spin_unlock_bh(&call->lock);
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iov[0].iov_base = pkt;
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iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
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iov[1].iov_base = &pkt->ackinfo;
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iov[1].iov_len = sizeof(pkt->ackinfo);
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len = iov[0].iov_len + iov[1].iov_len;
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serial = atomic_inc_return(&conn->serial);
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pkt->whdr.serial = htonl(serial);
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trace_rxrpc_tx_ack(call, serial,
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ntohl(pkt->ack.firstPacket),
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ntohl(pkt->ack.serial),
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pkt->ack.reason, pkt->ack.nAcks);
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if (ping) {
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call->ping_serial = serial;
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smp_wmb();
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/* We need to stick a time in before we send the packet in case
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* the reply gets back before kernel_sendmsg() completes - but
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* asking UDP to send the packet can take a relatively long
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* time, so we update the time after, on the assumption that
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* the packet transmission is more likely to happen towards the
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* end of the kernel_sendmsg() call.
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*/
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call->ping_time = ktime_get_real();
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set_bit(RXRPC_CALL_PINGING, &call->flags);
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trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
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}
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ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
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if (ping)
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call->ping_time = ktime_get_real();
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if (call->state < RXRPC_CALL_COMPLETE) {
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if (ret < 0) {
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if (ping)
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clear_bit(RXRPC_CALL_PINGING, &call->flags);
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rxrpc_propose_ACK(call, pkt->ack.reason,
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ntohs(pkt->ack.maxSkew),
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ntohl(pkt->ack.serial),
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true, true,
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rxrpc_propose_ack_retry_tx);
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} else {
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spin_lock_bh(&call->lock);
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if (after(hard_ack, call->ackr_consumed))
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call->ackr_consumed = hard_ack;
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if (after(top, call->ackr_seen))
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call->ackr_seen = top;
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spin_unlock_bh(&call->lock);
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}
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}
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out:
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kfree(pkt);
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return ret;
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}
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/*
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* Send an ABORT call packet.
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*/
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int rxrpc_send_abort_packet(struct rxrpc_call *call)
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{
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struct rxrpc_connection *conn;
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struct rxrpc_abort_buffer pkt;
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struct msghdr msg;
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struct kvec iov[1];
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rxrpc_serial_t serial;
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int ret;
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if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
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return -ECONNRESET;
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conn = call->conn;
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msg.msg_name = &call->peer->srx.transport;
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msg.msg_namelen = call->peer->srx.transport_len;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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msg.msg_flags = 0;
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pkt.whdr.epoch = htonl(conn->proto.epoch);
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pkt.whdr.cid = htonl(call->cid);
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pkt.whdr.callNumber = htonl(call->call_id);
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pkt.whdr.seq = 0;
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pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
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pkt.whdr.flags = conn->out_clientflag;
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pkt.whdr.userStatus = 0;
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pkt.whdr.securityIndex = call->security_ix;
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pkt.whdr._rsvd = 0;
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pkt.whdr.serviceId = htons(call->service_id);
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pkt.abort_code = htonl(call->abort_code);
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iov[0].iov_base = &pkt;
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iov[0].iov_len = sizeof(pkt);
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serial = atomic_inc_return(&conn->serial);
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pkt.whdr.serial = htonl(serial);
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ret = kernel_sendmsg(conn->params.local->socket,
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&msg, iov, 1, sizeof(pkt));
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return ret;
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}
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/*
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* send a packet through the transport endpoint
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*/
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int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
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bool retrans)
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{
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struct rxrpc_connection *conn = call->conn;
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struct rxrpc_wire_header whdr;
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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struct msghdr msg;
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struct kvec iov[2];
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rxrpc_serial_t serial;
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size_t len;
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bool lost = false;
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int ret, opt;
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_enter(",{%d}", skb->len);
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/* Each transmission of a Tx packet needs a new serial number */
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serial = atomic_inc_return(&conn->serial);
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whdr.epoch = htonl(conn->proto.epoch);
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whdr.cid = htonl(call->cid);
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whdr.callNumber = htonl(call->call_id);
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whdr.seq = htonl(sp->hdr.seq);
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whdr.serial = htonl(serial);
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whdr.type = RXRPC_PACKET_TYPE_DATA;
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whdr.flags = sp->hdr.flags;
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whdr.userStatus = 0;
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whdr.securityIndex = call->security_ix;
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whdr._rsvd = htons(sp->hdr._rsvd);
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whdr.serviceId = htons(call->service_id);
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iov[0].iov_base = &whdr;
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iov[0].iov_len = sizeof(whdr);
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iov[1].iov_base = skb->head;
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iov[1].iov_len = skb->len;
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len = iov[0].iov_len + iov[1].iov_len;
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msg.msg_name = &call->peer->srx.transport;
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msg.msg_namelen = call->peer->srx.transport_len;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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msg.msg_flags = 0;
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/* If our RTT cache needs working on, request an ACK. Also request
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* ACKs if a DATA packet appears to have been lost.
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*/
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if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
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(retrans ||
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call->cong_mode == RXRPC_CALL_SLOW_START ||
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(call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
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ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
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ktime_get_real())))
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whdr.flags |= RXRPC_REQUEST_ACK;
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if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
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static int lose;
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if ((lose++ & 7) == 7) {
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ret = 0;
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lost = true;
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goto done;
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}
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}
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_proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
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/* send the packet with the don't fragment bit set if we currently
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* think it's small enough */
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if (iov[1].iov_len >= call->peer->maxdata)
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goto send_fragmentable;
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down_read(&conn->params.local->defrag_sem);
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/* send the packet by UDP
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* - returns -EMSGSIZE if UDP would have to fragment the packet
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* to go out of the interface
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* - in which case, we'll have processed the ICMP error
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* message and update the peer record
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*/
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ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
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up_read(&conn->params.local->defrag_sem);
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if (ret == -EMSGSIZE)
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goto send_fragmentable;
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done:
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trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
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retrans, lost);
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if (ret >= 0) {
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ktime_t now = ktime_get_real();
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skb->tstamp = now;
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smp_wmb();
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sp->hdr.serial = serial;
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if (whdr.flags & RXRPC_REQUEST_ACK) {
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call->peer->rtt_last_req = now;
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trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
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}
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}
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_leave(" = %d [%u]", ret, call->peer->maxdata);
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return ret;
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|
send_fragmentable:
|
||
|
|
/* attempt to send this message with fragmentation enabled */
|
||
|
|
_debug("send fragment");
|
||
|
|
|
||
|
|
down_write(&conn->params.local->defrag_sem);
|
||
|
|
|
||
|
|
switch (conn->params.local->srx.transport.family) {
|
||
|
|
case AF_INET:
|
||
|
|
opt = IP_PMTUDISC_DONT;
|
||
|
|
ret = kernel_setsockopt(conn->params.local->socket,
|
||
|
|
SOL_IP, IP_MTU_DISCOVER,
|
||
|
|
(char *)&opt, sizeof(opt));
|
||
|
|
if (ret == 0) {
|
||
|
|
ret = kernel_sendmsg(conn->params.local->socket, &msg,
|
||
|
|
iov, 2, len);
|
||
|
|
|
||
|
|
opt = IP_PMTUDISC_DO;
|
||
|
|
kernel_setsockopt(conn->params.local->socket, SOL_IP,
|
||
|
|
IP_MTU_DISCOVER,
|
||
|
|
(char *)&opt, sizeof(opt));
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
#ifdef CONFIG_AF_RXRPC_IPV6
|
||
|
|
case AF_INET6:
|
||
|
|
opt = IPV6_PMTUDISC_DONT;
|
||
|
|
ret = kernel_setsockopt(conn->params.local->socket,
|
||
|
|
SOL_IPV6, IPV6_MTU_DISCOVER,
|
||
|
|
(char *)&opt, sizeof(opt));
|
||
|
|
if (ret == 0) {
|
||
|
|
ret = kernel_sendmsg(conn->params.local->socket, &msg,
|
||
|
|
iov, 2, len);
|
||
|
|
|
||
|
|
opt = IPV6_PMTUDISC_DO;
|
||
|
|
kernel_setsockopt(conn->params.local->socket,
|
||
|
|
SOL_IPV6, IPV6_MTU_DISCOVER,
|
||
|
|
(char *)&opt, sizeof(opt));
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
default:
|
||
|
|
BUG();
|
||
|
|
}
|
||
|
|
|
||
|
|
up_write(&conn->params.local->defrag_sem);
|
||
|
|
goto done;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* reject packets through the local endpoint
|
||
|
|
*/
|
||
|
|
void rxrpc_reject_packets(struct rxrpc_local *local)
|
||
|
|
{
|
||
|
|
struct sockaddr_rxrpc srx;
|
||
|
|
struct rxrpc_skb_priv *sp;
|
||
|
|
struct rxrpc_wire_header whdr;
|
||
|
|
struct sk_buff *skb;
|
||
|
|
struct msghdr msg;
|
||
|
|
struct kvec iov[2];
|
||
|
|
size_t size;
|
||
|
|
__be32 code;
|
||
|
|
|
||
|
|
_enter("%d", local->debug_id);
|
||
|
|
|
||
|
|
iov[0].iov_base = &whdr;
|
||
|
|
iov[0].iov_len = sizeof(whdr);
|
||
|
|
iov[1].iov_base = &code;
|
||
|
|
iov[1].iov_len = sizeof(code);
|
||
|
|
size = sizeof(whdr) + sizeof(code);
|
||
|
|
|
||
|
|
msg.msg_name = &srx.transport;
|
||
|
|
msg.msg_control = NULL;
|
||
|
|
msg.msg_controllen = 0;
|
||
|
|
msg.msg_flags = 0;
|
||
|
|
|
||
|
|
memset(&whdr, 0, sizeof(whdr));
|
||
|
|
whdr.type = RXRPC_PACKET_TYPE_ABORT;
|
||
|
|
|
||
|
|
while ((skb = skb_dequeue(&local->reject_queue))) {
|
||
|
|
rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
|
||
|
|
sp = rxrpc_skb(skb);
|
||
|
|
|
||
|
|
if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
|
||
|
|
msg.msg_namelen = srx.transport_len;
|
||
|
|
|
||
|
|
code = htonl(skb->priority);
|
||
|
|
|
||
|
|
whdr.epoch = htonl(sp->hdr.epoch);
|
||
|
|
whdr.cid = htonl(sp->hdr.cid);
|
||
|
|
whdr.callNumber = htonl(sp->hdr.callNumber);
|
||
|
|
whdr.serviceId = htons(sp->hdr.serviceId);
|
||
|
|
whdr.flags = sp->hdr.flags;
|
||
|
|
whdr.flags ^= RXRPC_CLIENT_INITIATED;
|
||
|
|
whdr.flags &= RXRPC_CLIENT_INITIATED;
|
||
|
|
|
||
|
|
kernel_sendmsg(local->socket, &msg, iov, 2, size);
|
||
|
|
}
|
||
|
|
|
||
|
|
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
|
||
|
|
}
|
||
|
|
|
||
|
|
_leave("");
|
||
|
|
}
|