[mirror_ubuntu-zesty-kernel.git] / net / rxrpc / output.c

/* RxRPC packet transmission
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/net.h>
#include <linux/gfp.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

struct rxrpc_ack_buffer {
	struct rxrpc_wire_header whdr;
	struct rxrpc_ackpacket ack;
	u8 acks[255];
	u8 pad[3];
	struct rxrpc_ackinfo ackinfo;
};

struct rxrpc_abort_buffer {
	struct rxrpc_wire_header whdr;
	__be32 abort_code;
};

/*
 * Fill out an ACK packet.
 */
static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
				 struct rxrpc_ack_buffer *pkt,
				 rxrpc_seq_t *_hard_ack,
				 rxrpc_seq_t *_top)
{
	rxrpc_serial_t serial;
	rxrpc_seq_t hard_ack, top, seq;
	int ix;
	u32 mtu, jmax;
	u8 *ackp = pkt->acks;

	/* Barrier against rxrpc_input_data(). */
	serial = call->ackr_serial;
	hard_ack = READ_ONCE(call->rx_hard_ack);
	top = smp_load_acquire(&call->rx_top);
	*_hard_ack = hard_ack;
	*_top = top;

	pkt->ack.bufferSpace	= htons(8);
	pkt->ack.maxSkew	= htons(call->ackr_skew);
	pkt->ack.firstPacket	= htonl(hard_ack + 1);
	pkt->ack.previousPacket	= htonl(call->ackr_prev_seq);
	pkt->ack.serial		= htonl(serial);
	pkt->ack.reason		= call->ackr_reason;
	pkt->ack.nAcks		= top - hard_ack;

	if (pkt->ack.reason == RXRPC_ACK_PING)
		pkt->whdr.flags |= RXRPC_REQUEST_ACK;

	if (after(top, hard_ack)) {
		seq = hard_ack + 1;
		do {
			ix = seq & RXRPC_RXTX_BUFF_MASK;
			if (call->rxtx_buffer[ix])
				*ackp++ = RXRPC_ACK_TYPE_ACK;
			else
				*ackp++ = RXRPC_ACK_TYPE_NACK;
			seq++;
		} while (before_eq(seq, top));
	}

	mtu = call->conn->params.peer->if_mtu;
	mtu -= call->conn->params.peer->hdrsize;
	jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
	pkt->ackinfo.rxMTU	= htonl(rxrpc_rx_mtu);
	pkt->ackinfo.maxMTU	= htonl(mtu);
	pkt->ackinfo.rwind	= htonl(call->rx_winsize);
	pkt->ackinfo.jumbo_max	= htonl(jmax);

	*ackp++ = 0;
	*ackp++ = 0;
	*ackp++ = 0;
	return top - hard_ack + 3;
}

/*
 * Send an ACK call packet.
 */
int rxrpc_send_ack_packet(struct rxrpc_call *call)
{
	struct rxrpc_connection *conn = NULL;
	struct rxrpc_ack_buffer *pkt;
	struct msghdr msg;
	struct kvec iov[2];
	rxrpc_serial_t serial;
	rxrpc_seq_t hard_ack, top;
	size_t len, n;
	bool ping = false;
	int ret;

	spin_lock_bh(&call->lock);
	if (call->conn)
		conn = rxrpc_get_connection_maybe(call->conn);
	spin_unlock_bh(&call->lock);
	if (!conn)
		return -ECONNRESET;

	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
	if (!pkt) {
		rxrpc_put_connection(conn);
		return -ENOMEM;
	}

	msg.msg_name	= &call->peer->srx.transport;
	msg.msg_namelen	= call->peer->srx.transport_len;
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	pkt->whdr.epoch		= htonl(conn->proto.epoch);
	pkt->whdr.cid		= htonl(call->cid);
	pkt->whdr.callNumber	= htonl(call->call_id);
	pkt->whdr.seq		= 0;
	pkt->whdr.type		= RXRPC_PACKET_TYPE_ACK;
	pkt->whdr.flags		= RXRPC_SLOW_START_OK | conn->out_clientflag;
	pkt->whdr.userStatus	= 0;
	pkt->whdr.securityIndex	= call->security_ix;
	pkt->whdr._rsvd		= 0;
	pkt->whdr.serviceId	= htons(call->service_id);

	spin_lock_bh(&call->lock);
	if (!call->ackr_reason) {
		spin_unlock_bh(&call->lock);
		ret = 0;
		goto out;
	}
	ping = (call->ackr_reason == RXRPC_ACK_PING);
	n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
	call->ackr_reason = 0;

	spin_unlock_bh(&call->lock);

	iov[0].iov_base	= pkt;
	iov[0].iov_len	= sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
	iov[1].iov_base = &pkt->ackinfo;
	iov[1].iov_len	= sizeof(pkt->ackinfo);
	len = iov[0].iov_len + iov[1].iov_len;

	serial = atomic_inc_return(&conn->serial);
	pkt->whdr.serial = htonl(serial);
	trace_rxrpc_tx_ack(call, serial,
			   ntohl(pkt->ack.firstPacket),
			   ntohl(pkt->ack.serial),
			   pkt->ack.reason, pkt->ack.nAcks);

	if (ping) {
		call->ackr_ping = serial;
		smp_wmb();
		/* We need to stick a time in before we send the packet in case
		 * the reply gets back before kernel_sendmsg() completes - but
		 * asking UDP to send the packet can take a relatively long
		 * time, so we update the time after, on the assumption that
		 * the packet transmission is more likely to happen towards the
		 * end of the kernel_sendmsg() call.
		 */
		call->ackr_ping_time = ktime_get_real();
		set_bit(RXRPC_CALL_PINGING, &call->flags);
		trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
	}

	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
	if (ping)
		call->ackr_ping_time = ktime_get_real();

	if (call->state < RXRPC_CALL_COMPLETE) {
		if (ret < 0) {
			clear_bit(RXRPC_CALL_PINGING, &call->flags);
			rxrpc_propose_ACK(call, pkt->ack.reason,
					  ntohs(pkt->ack.maxSkew),
					  ntohl(pkt->ack.serial),
					  true, true,
					  rxrpc_propose_ack_retry_tx);
		} else {
			spin_lock_bh(&call->lock);
			if (after(hard_ack, call->ackr_consumed))
				call->ackr_consumed = hard_ack;
			if (after(top, call->ackr_seen))
				call->ackr_seen = top;
			spin_unlock_bh(&call->lock);
		}
	}

out:
	rxrpc_put_connection(conn);
	kfree(pkt);
	return ret;
}

/*
 * Send an ABORT call packet.
 */
int rxrpc_send_abort_packet(struct rxrpc_call *call)
{
	struct rxrpc_connection *conn = NULL;
	struct rxrpc_abort_buffer pkt;
	struct msghdr msg;
	struct kvec iov[1];
	rxrpc_serial_t serial;
	int ret;

	spin_lock_bh(&call->lock);
	if (call->conn)
		conn = rxrpc_get_connection_maybe(call->conn);
	spin_unlock_bh(&call->lock);
	if (!conn)
		return -ECONNRESET;

	msg.msg_name	= &call->peer->srx.transport;
	msg.msg_namelen	= call->peer->srx.transport_len;
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	pkt.whdr.epoch		= htonl(conn->proto.epoch);
	pkt.whdr.cid		= htonl(call->cid);
	pkt.whdr.callNumber	= htonl(call->call_id);
	pkt.whdr.seq		= 0;
	pkt.whdr.type		= RXRPC_PACKET_TYPE_ABORT;
	pkt.whdr.flags		= conn->out_clientflag;
	pkt.whdr.userStatus	= 0;
	pkt.whdr.securityIndex	= call->security_ix;
	pkt.whdr._rsvd		= 0;
	pkt.whdr.serviceId	= htons(call->service_id);
	pkt.abort_code		= htonl(call->abort_code);

	iov[0].iov_base	= &pkt;
	iov[0].iov_len	= sizeof(pkt);

	serial = atomic_inc_return(&conn->serial);
	pkt.whdr.serial = htonl(serial);

	ret = kernel_sendmsg(conn->params.local->socket,
			     &msg, iov, 1, sizeof(pkt));

	rxrpc_put_connection(conn);
	return ret;
}

/*
 * send a packet through the transport endpoint
 */
int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
			   bool retrans)
{
	struct rxrpc_connection *conn = call->conn;
	struct rxrpc_wire_header whdr;
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	struct msghdr msg;
	struct kvec iov[2];
	rxrpc_serial_t serial;
	size_t len;
	bool lost = false;
	int ret, opt;

	_enter(",{%d}", skb->len);

	/* Each transmission of a Tx packet needs a new serial number */
	serial = atomic_inc_return(&conn->serial);

	whdr.epoch	= htonl(conn->proto.epoch);
	whdr.cid	= htonl(call->cid);
	whdr.callNumber	= htonl(call->call_id);
	whdr.seq	= htonl(sp->hdr.seq);
	whdr.serial	= htonl(serial);
	whdr.type	= RXRPC_PACKET_TYPE_DATA;
	whdr.flags	= sp->hdr.flags;
	whdr.userStatus	= 0;
	whdr.securityIndex = call->security_ix;
	whdr._rsvd	= htons(sp->hdr._rsvd);
	whdr.serviceId	= htons(call->service_id);

	iov[0].iov_base = &whdr;
	iov[0].iov_len = sizeof(whdr);
	iov[1].iov_base = skb->head;
	iov[1].iov_len = skb->len;
	len = iov[0].iov_len + iov[1].iov_len;

	msg.msg_name = &call->peer->srx.transport;
	msg.msg_namelen = call->peer->srx.transport_len;
	msg.msg_control = NULL;
	msg.msg_controllen = 0;
	msg.msg_flags = 0;

	/* If our RTT cache needs working on, request an ACK.  Also request
	 * ACKs if a DATA packet appears to have been lost.
	 */
	if (retrans ||
	    call->cong_mode == RXRPC_CALL_SLOW_START ||
	    (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
	    ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
			 ktime_get_real()))
		whdr.flags |= RXRPC_REQUEST_ACK;

	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
		static int lose;
		if ((lose++ & 7) == 7) {
			ret = 0;
			lost = true;
			goto done;
		}
	}

	_proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);

	/* send the packet with the don't fragment bit set if we currently
	 * think it's small enough */
	if (iov[1].iov_len >= call->peer->maxdata)
		goto send_fragmentable;

	down_read(&conn->params.local->defrag_sem);
	/* send the packet by UDP
	 * - returns -EMSGSIZE if UDP would have to fragment the packet
	 *   to go out of the interface
	 *   - in which case, we'll have processed the ICMP error
	 *     message and update the peer record
	 */
	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);

	up_read(&conn->params.local->defrag_sem);
	if (ret == -EMSGSIZE)
		goto send_fragmentable;

done:
	trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
			    retrans, lost);
	if (ret >= 0) {
		ktime_t now = ktime_get_real();
		skb->tstamp = now;
		smp_wmb();
		sp->hdr.serial = serial;
		if (whdr.flags & RXRPC_REQUEST_ACK) {
			call->peer->rtt_last_req = now;
			trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
		}
	}
	_leave(" = %d [%u]", ret, call->peer->maxdata);
	return ret;

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, 1, iov[0].iov_len);

			opt = IPV6_PMTUDISC_DO;
			kernel_setsockopt(conn->params.local->socket,
					  SOL_IPV6, IPV6_MTU_DISCOVER,
					  (char *)&opt, sizeof(opt));
		}
		break;
#endif
	}

	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("");
}
Commit	Line	Data
17926a79 DH	1	/* RxRPC packet transmission
	2	*
	3	* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
9b6d5398 JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9b6d5398 JP	13
17926a79	14	#include <linux/net.h>
5a0e3ad6	15	#include <linux/gfp.h>
17926a79	16	#include <linux/skbuff.h>
bc3b2d7f	17	#include <linux/export.h>
17926a79 DH	18	#include <net/sock.h>
	19	#include <net/af_rxrpc.h>
	20	#include "ar-internal.h"
	21
26cb02aa	22	struct rxrpc_ack_buffer {
8d94aa38	23	struct rxrpc_wire_header whdr;
26cb02aa DH	24	struct rxrpc_ackpacket ack;
	25	u8 acks[255];
	26	u8 pad[3];
8d94aa38 DH	27	struct rxrpc_ackinfo ackinfo;
	28	};
	29
26cb02aa DH	30	struct rxrpc_abort_buffer {
	31	struct rxrpc_wire_header whdr;
	32	__be32 abort_code;
	33	};
	34
8d94aa38 DH	35	/*
	36	* Fill out an ACK packet.
	37	*/
	38	static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
26cb02aa	39	struct rxrpc_ack_buffer *pkt,
805b21b9 DH	40	rxrpc_seq_t *_hard_ack,
805b21b9 DH	41	rxrpc_seq_t *_top)
8d94aa38	42	{
f3639df2	43	rxrpc_serial_t serial;
248f219c DH	44	rxrpc_seq_t hard_ack, top, seq;
248f219c DH	45	int ix;
8d94aa38 DH	46	u32 mtu, jmax;
	47	u8 *ackp = pkt->acks;
	48
248f219c	49	/* Barrier against rxrpc_input_data(). */
f3639df2	50	serial = call->ackr_serial;
248f219c DH	51	hard_ack = READ_ONCE(call->rx_hard_ack);
248f219c DH	52	top = smp_load_acquire(&call->rx_top);
805b21b9 DH	53	*_hard_ack = hard_ack;
805b21b9 DH	54	*_top = top;
248f219c	55
8d94aa38	56	pkt->ack.bufferSpace = htons(8);
248f219c DH	57	pkt->ack.maxSkew = htons(call->ackr_skew);
248f219c DH	58	pkt->ack.firstPacket = htonl(hard_ack + 1);
8d94aa38	59	pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
f3639df2	60	pkt->ack.serial = htonl(serial);
248f219c DH	61	pkt->ack.reason = call->ackr_reason;
	62	pkt->ack.nAcks = top - hard_ack;
	63
8e83134d DH	64	if (pkt->ack.reason == RXRPC_ACK_PING)
	65	pkt->whdr.flags \|= RXRPC_REQUEST_ACK;
	66
248f219c DH	67	if (after(top, hard_ack)) {
	68	seq = hard_ack + 1;
	69	do {
	70	ix = seq & RXRPC_RXTX_BUFF_MASK;
	71	if (call->rxtx_buffer[ix])
	72	*ackp++ = RXRPC_ACK_TYPE_ACK;
	73	else
	74	*ackp++ = RXRPC_ACK_TYPE_NACK;
	75	seq++;
	76	} while (before_eq(seq, top));
	77	}
8d94aa38	78
248f219c DH	79	mtu = call->conn->params.peer->if_mtu;
248f219c DH	80	mtu -= call->conn->params.peer->hdrsize;
75e42126	81	jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
8d94aa38 DH	82	pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
8d94aa38 DH	83	pkt->ackinfo.maxMTU = htonl(mtu);
75e42126	84	pkt->ackinfo.rwind = htonl(call->rx_winsize);
8d94aa38 DH	85	pkt->ackinfo.jumbo_max = htonl(jmax);
	86
	87	*ackp++ = 0;
	88	*ackp++ = 0;
	89	*ackp++ = 0;
248f219c	90	return top - hard_ack + 3;
8d94aa38 DH	91	}
	92
	93	/*
26cb02aa	94	* Send an ACK call packet.
8d94aa38	95	*/
26cb02aa	96	int rxrpc_send_ack_packet(struct rxrpc_call *call)
8d94aa38 DH	97	{
8d94aa38 DH	98	struct rxrpc_connection *conn = NULL;
26cb02aa	99	struct rxrpc_ack_buffer *pkt;
8d94aa38 DH	100	struct msghdr msg;
	101	struct kvec iov[2];
	102	rxrpc_serial_t serial;
805b21b9	103	rxrpc_seq_t hard_ack, top;
8d94aa38	104	size_t len, n;
8e83134d	105	bool ping = false;
26cb02aa	106	int ret;
8d94aa38 DH	107
	108	spin_lock_bh(&call->lock);
	109	if (call->conn)
	110	conn = rxrpc_get_connection_maybe(call->conn);
	111	spin_unlock_bh(&call->lock);
	112	if (!conn)
	113	return -ECONNRESET;
	114
	115	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
	116	if (!pkt) {
	117	rxrpc_put_connection(conn);
	118	return -ENOMEM;
	119	}
	120
8d94aa38 DH	121	msg.msg_name = &call->peer->srx.transport;
	122	msg.msg_namelen = call->peer->srx.transport_len;
	123	msg.msg_control = NULL;
	124	msg.msg_controllen = 0;
	125	msg.msg_flags = 0;
	126
	127	pkt->whdr.epoch = htonl(conn->proto.epoch);
	128	pkt->whdr.cid = htonl(call->cid);
	129	pkt->whdr.callNumber = htonl(call->call_id);
	130	pkt->whdr.seq = 0;
26cb02aa DH	131	pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
26cb02aa DH	132	pkt->whdr.flags = RXRPC_SLOW_START_OK \| conn->out_clientflag;
8d94aa38 DH	133	pkt->whdr.userStatus = 0;
	134	pkt->whdr.securityIndex = call->security_ix;
	135	pkt->whdr._rsvd = 0;
	136	pkt->whdr.serviceId = htons(call->service_id);
	137
26cb02aa DH	138	spin_lock_bh(&call->lock);
26cb02aa DH	139	if (!call->ackr_reason) {
8d94aa38	140	spin_unlock_bh(&call->lock);
26cb02aa	141	ret = 0;
8d94aa38 DH	142	goto out;
8d94aa38 DH	143	}
26cb02aa DH	144	ping = (call->ackr_reason == RXRPC_ACK_PING);
	145	n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
	146	call->ackr_reason = 0;
	147
	148	spin_unlock_bh(&call->lock);
	149
	150	iov[0].iov_base = pkt;
	151	iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
	152	iov[1].iov_base = &pkt->ackinfo;
	153	iov[1].iov_len = sizeof(pkt->ackinfo);
	154	len = iov[0].iov_len + iov[1].iov_len;
8d94aa38	155
b86e218e DH	156	serial = atomic_inc_return(&conn->serial);
b86e218e DH	157	pkt->whdr.serial = htonl(serial);
26cb02aa DH	158	trace_rxrpc_tx_ack(call, serial,
	159	ntohl(pkt->ack.firstPacket),
	160	ntohl(pkt->ack.serial),
	161	pkt->ack.reason, pkt->ack.nAcks);
b86e218e	162
8e83134d DH	163	if (ping) {
	164	call->ackr_ping = serial;
	165	smp_wmb();
	166	/* We need to stick a time in before we send the packet in case
	167	* the reply gets back before kernel_sendmsg() completes - but
	168	* asking UDP to send the packet can take a relatively long
	169	* time, so we update the time after, on the assumption that
	170	* the packet transmission is more likely to happen towards the
	171	* end of the kernel_sendmsg() call.
	172	*/
	173	call->ackr_ping_time = ktime_get_real();
	174	set_bit(RXRPC_CALL_PINGING, &call->flags);
	175	trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
	176	}
26cb02aa DH	177
26cb02aa DH	178	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
8e83134d DH	179	if (ping)
8e83134d DH	180	call->ackr_ping_time = ktime_get_real();
8d94aa38	181
26cb02aa	182	if (call->state < RXRPC_CALL_COMPLETE) {
805b21b9	183	if (ret < 0) {
8e83134d	184	clear_bit(RXRPC_CALL_PINGING, &call->flags);
248f219c DH	185	rxrpc_propose_ACK(call, pkt->ack.reason,
	186	ntohs(pkt->ack.maxSkew),
	187	ntohl(pkt->ack.serial),
9c7ad434 DH	188	true, true,
9c7ad434 DH	189	rxrpc_propose_ack_retry_tx);
805b21b9 DH	190	} else {
	191	spin_lock_bh(&call->lock);
	192	if (after(hard_ack, call->ackr_consumed))
	193	call->ackr_consumed = hard_ack;
	194	if (after(top, call->ackr_seen))
	195	call->ackr_seen = top;
	196	spin_unlock_bh(&call->lock);
248f219c DH	197	}
	198	}
	199
8d94aa38 DH	200	out:
	201	rxrpc_put_connection(conn);
	202	kfree(pkt);
	203	return ret;
	204	}
	205
26cb02aa DH	206	/*
	207	* Send an ABORT call packet.
	208	*/
	209	int rxrpc_send_abort_packet(struct rxrpc_call *call)
	210	{
	211	struct rxrpc_connection *conn = NULL;
	212	struct rxrpc_abort_buffer pkt;
	213	struct msghdr msg;
	214	struct kvec iov[1];
	215	rxrpc_serial_t serial;
	216	int ret;
	217
	218	spin_lock_bh(&call->lock);
	219	if (call->conn)
	220	conn = rxrpc_get_connection_maybe(call->conn);
	221	spin_unlock_bh(&call->lock);
	222	if (!conn)
	223	return -ECONNRESET;
	224
	225	msg.msg_name = &call->peer->srx.transport;
	226	msg.msg_namelen = call->peer->srx.transport_len;
	227	msg.msg_control = NULL;
	228	msg.msg_controllen = 0;
	229	msg.msg_flags = 0;
	230
	231	pkt.whdr.epoch = htonl(conn->proto.epoch);
	232	pkt.whdr.cid = htonl(call->cid);
	233	pkt.whdr.callNumber = htonl(call->call_id);
	234	pkt.whdr.seq = 0;
	235	pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
	236	pkt.whdr.flags = conn->out_clientflag;
	237	pkt.whdr.userStatus = 0;
	238	pkt.whdr.securityIndex = call->security_ix;
	239	pkt.whdr._rsvd = 0;
	240	pkt.whdr.serviceId = htons(call->service_id);
	241	pkt.abort_code = htonl(call->abort_code);
	242
	243	iov[0].iov_base = &pkt;
	244	iov[0].iov_len = sizeof(pkt);
	245
	246	serial = atomic_inc_return(&conn->serial);
	247	pkt.whdr.serial = htonl(serial);
	248
	249	ret = kernel_sendmsg(conn->params.local->socket,
	250	&msg, iov, 1, sizeof(pkt));
	251
	252	rxrpc_put_connection(conn);
	253	return ret;
	254	}
	255
17926a79 DH	256	/*
	257	* send a packet through the transport endpoint
	258	*/
a1767077 DH	259	int rxrpc_send_data_packet(struct rxrpc_call call, struct sk_buff skb,
a1767077 DH	260	bool retrans)
17926a79	261	{
5a924b89 DH	262	struct rxrpc_connection *conn = call->conn;
	263	struct rxrpc_wire_header whdr;
	264	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
17926a79	265	struct msghdr msg;
5a924b89 DH	266	struct kvec iov[2];
	267	rxrpc_serial_t serial;
	268	size_t len;
a1767077	269	bool lost = false;
17926a79 DH	270	int ret, opt;
	271
	272	_enter(",{%d}", skb->len);
	273
5a924b89 DH	274	/* Each transmission of a Tx packet needs a new serial number */
5a924b89 DH	275	serial = atomic_inc_return(&conn->serial);
17926a79	276
5a924b89 DH	277	whdr.epoch = htonl(conn->proto.epoch);
	278	whdr.cid = htonl(call->cid);
	279	whdr.callNumber = htonl(call->call_id);
	280	whdr.seq = htonl(sp->hdr.seq);
	281	whdr.serial = htonl(serial);
	282	whdr.type = RXRPC_PACKET_TYPE_DATA;
	283	whdr.flags = sp->hdr.flags;
	284	whdr.userStatus = 0;
	285	whdr.securityIndex = call->security_ix;
	286	whdr._rsvd = htons(sp->hdr._rsvd);
	287	whdr.serviceId = htons(call->service_id);
	288
	289	iov[0].iov_base = &whdr;
	290	iov[0].iov_len = sizeof(whdr);
	291	iov[1].iov_base = skb->head;
	292	iov[1].iov_len = skb->len;
	293	len = iov[0].iov_len + iov[1].iov_len;
	294
	295	msg.msg_name = &call->peer->srx.transport;
	296	msg.msg_namelen = call->peer->srx.transport_len;
17926a79 DH	297	msg.msg_control = NULL;
	298	msg.msg_controllen = 0;
	299	msg.msg_flags = 0;
	300
57494343 DH	301	/* If our RTT cache needs working on, request an ACK. Also request
	302	* ACKs if a DATA packet appears to have been lost.
	303	*/
a1767077	304	if (retrans \|\|
b112a670	305	call->cong_mode == RXRPC_CALL_SLOW_START \|\|
57494343	306	(call->peer->rtt_usage < 3 && sp->hdr.seq & 1) \|\|
0d4b103c DH	307	ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
	308	ktime_get_real()))
	309	whdr.flags \|= RXRPC_REQUEST_ACK;
	310
8a681c36 DH	311	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
	312	static int lose;
	313	if ((lose++ & 7) == 7) {
a1767077 DH	314	ret = 0;
	315	lost = true;
	316	goto done;
8a681c36 DH	317	}
	318	}
	319
5a924b89 DH	320	_proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
5a924b89 DH	321
17926a79 DH	322	/* send the packet with the don't fragment bit set if we currently
17926a79 DH	323	* think it's small enough */
5a924b89 DH	324	if (iov[1].iov_len >= call->peer->maxdata)
	325	goto send_fragmentable;
	326
	327	down_read(&conn->params.local->defrag_sem);
	328	/* send the packet by UDP
	329	* - returns -EMSGSIZE if UDP would have to fragment the packet
	330	* to go out of the interface
	331	* - in which case, we'll have processed the ICMP error
	332	* message and update the peer record
	333	*/
	334	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
	335
	336	up_read(&conn->params.local->defrag_sem);
	337	if (ret == -EMSGSIZE)
	338	goto send_fragmentable;
	339
	340	done:
a1767077 DH	341	trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
a1767077 DH	342	retrans, lost);
50235c4b	343	if (ret >= 0) {
0d4b103c DH	344	ktime_t now = ktime_get_real();
0d4b103c DH	345	skb->tstamp = now;
50235c4b	346	smp_wmb();
5a924b89	347	sp->hdr.serial = serial;
0d4b103c DH	348	if (whdr.flags & RXRPC_REQUEST_ACK) {
0d4b103c DH	349	call->peer->rtt_last_req = now;
50235c4b	350	trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
0d4b103c	351	}
17926a79	352	}
5a924b89 DH	353	_leave(" = %d [%u]", ret, call->peer->maxdata);
5a924b89 DH	354	return ret;
17926a79 DH	355
	356	send_fragmentable:
	357	/* attempt to send this message with fragmentation enabled */
	358	_debug("send fragment");
	359
985a5c82 DH	360	down_write(&conn->params.local->defrag_sem);
	361
	362	switch (conn->params.local->srx.transport.family) {
	363	case AF_INET:
	364	opt = IP_PMTUDISC_DONT;
	365	ret = kernel_setsockopt(conn->params.local->socket,
	366	SOL_IP, IP_MTU_DISCOVER,
	367	(char *)&opt, sizeof(opt));
	368	if (ret == 0) {
5a924b89 DH	369	ret = kernel_sendmsg(conn->params.local->socket, &msg,
5a924b89 DH	370	iov, 2, len);
985a5c82 DH	371
	372	opt = IP_PMTUDISC_DO;
	373	kernel_setsockopt(conn->params.local->socket, SOL_IP,
	374	IP_MTU_DISCOVER,
	375	(char *)&opt, sizeof(opt));
	376	}
	377	break;
75b54cb5	378
d1912747	379	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	380	case AF_INET6:
	381	opt = IPV6_PMTUDISC_DONT;
	382	ret = kernel_setsockopt(conn->params.local->socket,
	383	SOL_IPV6, IPV6_MTU_DISCOVER,
	384	(char *)&opt, sizeof(opt));
	385	if (ret == 0) {
	386	ret = kernel_sendmsg(conn->params.local->socket, &msg,
	387	iov, 1, iov[0].iov_len);
	388
	389	opt = IPV6_PMTUDISC_DO;
	390	kernel_setsockopt(conn->params.local->socket,
	391	SOL_IPV6, IPV6_MTU_DISCOVER,
	392	(char *)&opt, sizeof(opt));
	393	}
	394	break;
d1912747	395	#endif
17926a79 DH	396	}
17926a79 DH	397
985a5c82	398	up_write(&conn->params.local->defrag_sem);
5a924b89	399	goto done;
17926a79	400	}
248f219c DH	401
	402	/*
	403	* reject packets through the local endpoint
	404	*/
	405	void rxrpc_reject_packets(struct rxrpc_local *local)
	406	{
1c2bc7b9	407	struct sockaddr_rxrpc srx;
248f219c DH	408	struct rxrpc_skb_priv *sp;
	409	struct rxrpc_wire_header whdr;
	410	struct sk_buff *skb;
	411	struct msghdr msg;
	412	struct kvec iov[2];
	413	size_t size;
	414	__be32 code;
	415
	416	_enter("%d", local->debug_id);
	417
	418	iov[0].iov_base = &whdr;
	419	iov[0].iov_len = sizeof(whdr);
	420	iov[1].iov_base = &code;
	421	iov[1].iov_len = sizeof(code);
	422	size = sizeof(whdr) + sizeof(code);
	423
1c2bc7b9	424	msg.msg_name = &srx.transport;
248f219c DH	425	msg.msg_control = NULL;
	426	msg.msg_controllen = 0;
	427	msg.msg_flags = 0;
	428
248f219c DH	429	memset(&whdr, 0, sizeof(whdr));
	430	whdr.type = RXRPC_PACKET_TYPE_ABORT;
	431
	432	while ((skb = skb_dequeue(&local->reject_queue))) {
71f3ca40	433	rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
248f219c	434	sp = rxrpc_skb(skb);
1c2bc7b9 DH	435
	436	if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
	437	msg.msg_namelen = srx.transport_len;
	438
248f219c DH	439	code = htonl(skb->priority);
	440
	441	whdr.epoch = htonl(sp->hdr.epoch);
	442	whdr.cid = htonl(sp->hdr.cid);
	443	whdr.callNumber = htonl(sp->hdr.callNumber);
	444	whdr.serviceId = htons(sp->hdr.serviceId);
	445	whdr.flags = sp->hdr.flags;
	446	whdr.flags ^= RXRPC_CLIENT_INITIATED;
	447	whdr.flags &= RXRPC_CLIENT_INITIATED;
	448
	449	kernel_sendmsg(local->socket, &msg, iov, 2, size);
248f219c DH	450	}
248f219c DH	451
71f3ca40	452	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
248f219c DH	453	}
	454
	455	_leave("");
	456	}