[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,
				 u8 reason)
{
	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		= reason;
	pkt->ack.nAcks		= top - hard_ack;

	if (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, bool ping)
{
	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;
	int ret;
	u8 reason;

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

	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->ping_serial = 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->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->ping_time = ktime_get_real();

	if (call->state < RXRPC_CALL_COMPLETE) {
		if (ret < 0) {
			if (ping)
				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 (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
	    (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	40	rxrpc_seq_t *_hard_ack,
a5af7e1f DH	41	rxrpc_seq_t *_top,
a5af7e1f DH	42	u8 reason)
8d94aa38	43	{
f3639df2	44	rxrpc_serial_t serial;
248f219c DH	45	rxrpc_seq_t hard_ack, top, seq;
248f219c DH	46	int ix;
8d94aa38 DH	47	u32 mtu, jmax;
	48	u8 *ackp = pkt->acks;
	49
248f219c	50	/* Barrier against rxrpc_input_data(). */
f3639df2	51	serial = call->ackr_serial;
248f219c DH	52	hard_ack = READ_ONCE(call->rx_hard_ack);
248f219c DH	53	top = smp_load_acquire(&call->rx_top);
805b21b9 DH	54	*_hard_ack = hard_ack;
805b21b9 DH	55	*_top = top;
248f219c	56
8d94aa38	57	pkt->ack.bufferSpace = htons(8);
248f219c DH	58	pkt->ack.maxSkew = htons(call->ackr_skew);
248f219c DH	59	pkt->ack.firstPacket = htonl(hard_ack + 1);
8d94aa38	60	pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
f3639df2	61	pkt->ack.serial = htonl(serial);
a5af7e1f	62	pkt->ack.reason = reason;
248f219c DH	63	pkt->ack.nAcks = top - hard_ack;
248f219c DH	64
a5af7e1f	65	if (reason == RXRPC_ACK_PING)
8e83134d DH	66	pkt->whdr.flags \|= RXRPC_REQUEST_ACK;
8e83134d DH	67
248f219c DH	68	if (after(top, hard_ack)) {
	69	seq = hard_ack + 1;
	70	do {
	71	ix = seq & RXRPC_RXTX_BUFF_MASK;
	72	if (call->rxtx_buffer[ix])
	73	*ackp++ = RXRPC_ACK_TYPE_ACK;
	74	else
	75	*ackp++ = RXRPC_ACK_TYPE_NACK;
	76	seq++;
	77	} while (before_eq(seq, top));
	78	}
8d94aa38	79
248f219c DH	80	mtu = call->conn->params.peer->if_mtu;
248f219c DH	81	mtu -= call->conn->params.peer->hdrsize;
75e42126	82	jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
8d94aa38 DH	83	pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
8d94aa38 DH	84	pkt->ackinfo.maxMTU = htonl(mtu);
75e42126	85	pkt->ackinfo.rwind = htonl(call->rx_winsize);
8d94aa38 DH	86	pkt->ackinfo.jumbo_max = htonl(jmax);
	87
	88	*ackp++ = 0;
	89	*ackp++ = 0;
	90	*ackp++ = 0;
248f219c	91	return top - hard_ack + 3;
8d94aa38 DH	92	}
	93
	94	/*
26cb02aa	95	* Send an ACK call packet.
8d94aa38	96	*/
a5af7e1f	97	int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
8d94aa38 DH	98	{
8d94aa38 DH	99	struct rxrpc_connection *conn = NULL;
26cb02aa	100	struct rxrpc_ack_buffer *pkt;
8d94aa38 DH	101	struct msghdr msg;
	102	struct kvec iov[2];
	103	rxrpc_serial_t serial;
805b21b9	104	rxrpc_seq_t hard_ack, top;
8d94aa38	105	size_t len, n;
26cb02aa	106	int ret;
a5af7e1f	107	u8 reason;
8d94aa38 DH	108
	109	spin_lock_bh(&call->lock);
	110	if (call->conn)
	111	conn = rxrpc_get_connection_maybe(call->conn);
	112	spin_unlock_bh(&call->lock);
	113	if (!conn)
	114	return -ECONNRESET;
	115
	116	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
	117	if (!pkt) {
	118	rxrpc_put_connection(conn);
	119	return -ENOMEM;
	120	}
	121
8d94aa38 DH	122	msg.msg_name = &call->peer->srx.transport;
	123	msg.msg_namelen = call->peer->srx.transport_len;
	124	msg.msg_control = NULL;
	125	msg.msg_controllen = 0;
	126	msg.msg_flags = 0;
	127
	128	pkt->whdr.epoch = htonl(conn->proto.epoch);
	129	pkt->whdr.cid = htonl(call->cid);
	130	pkt->whdr.callNumber = htonl(call->call_id);
	131	pkt->whdr.seq = 0;
26cb02aa DH	132	pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
26cb02aa DH	133	pkt->whdr.flags = RXRPC_SLOW_START_OK \| conn->out_clientflag;
8d94aa38 DH	134	pkt->whdr.userStatus = 0;
	135	pkt->whdr.securityIndex = call->security_ix;
	136	pkt->whdr._rsvd = 0;
	137	pkt->whdr.serviceId = htons(call->service_id);
	138
26cb02aa	139	spin_lock_bh(&call->lock);
a5af7e1f DH	140	if (ping) {
	141	reason = RXRPC_ACK_PING;
	142	} else {
	143	reason = call->ackr_reason;
	144	if (!call->ackr_reason) {
	145	spin_unlock_bh(&call->lock);
	146	ret = 0;
	147	goto out;
	148	}
	149	call->ackr_reason = 0;
8d94aa38	150	}
a5af7e1f	151	n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top, reason);
26cb02aa DH	152
	153	spin_unlock_bh(&call->lock);
	154
	155	iov[0].iov_base = pkt;
	156	iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
	157	iov[1].iov_base = &pkt->ackinfo;
	158	iov[1].iov_len = sizeof(pkt->ackinfo);
	159	len = iov[0].iov_len + iov[1].iov_len;
8d94aa38	160
b86e218e DH	161	serial = atomic_inc_return(&conn->serial);
b86e218e DH	162	pkt->whdr.serial = htonl(serial);
26cb02aa DH	163	trace_rxrpc_tx_ack(call, serial,
	164	ntohl(pkt->ack.firstPacket),
	165	ntohl(pkt->ack.serial),
	166	pkt->ack.reason, pkt->ack.nAcks);
b86e218e	167
8e83134d	168	if (ping) {
a5af7e1f	169	call->ping_serial = serial;
8e83134d DH	170	smp_wmb();
	171	/* We need to stick a time in before we send the packet in case
	172	* the reply gets back before kernel_sendmsg() completes - but
	173	* asking UDP to send the packet can take a relatively long
	174	* time, so we update the time after, on the assumption that
	175	* the packet transmission is more likely to happen towards the
	176	* end of the kernel_sendmsg() call.
	177	*/
a5af7e1f	178	call->ping_time = ktime_get_real();
8e83134d DH	179	set_bit(RXRPC_CALL_PINGING, &call->flags);
	180	trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
	181	}
26cb02aa DH	182
26cb02aa DH	183	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
8e83134d	184	if (ping)
a5af7e1f	185	call->ping_time = ktime_get_real();
8d94aa38	186
26cb02aa	187	if (call->state < RXRPC_CALL_COMPLETE) {
805b21b9	188	if (ret < 0) {
a5af7e1f DH	189	if (ping)
a5af7e1f DH	190	clear_bit(RXRPC_CALL_PINGING, &call->flags);
248f219c DH	191	rxrpc_propose_ACK(call, pkt->ack.reason,
	192	ntohs(pkt->ack.maxSkew),
	193	ntohl(pkt->ack.serial),
9c7ad434 DH	194	true, true,
9c7ad434 DH	195	rxrpc_propose_ack_retry_tx);
805b21b9 DH	196	} else {
	197	spin_lock_bh(&call->lock);
	198	if (after(hard_ack, call->ackr_consumed))
	199	call->ackr_consumed = hard_ack;
	200	if (after(top, call->ackr_seen))
	201	call->ackr_seen = top;
	202	spin_unlock_bh(&call->lock);
248f219c DH	203	}
	204	}
	205
8d94aa38 DH	206	out:
	207	rxrpc_put_connection(conn);
	208	kfree(pkt);
	209	return ret;
	210	}
	211
26cb02aa DH	212	/*
	213	* Send an ABORT call packet.
	214	*/
	215	int rxrpc_send_abort_packet(struct rxrpc_call *call)
	216	{
	217	struct rxrpc_connection *conn = NULL;
	218	struct rxrpc_abort_buffer pkt;
	219	struct msghdr msg;
	220	struct kvec iov[1];
	221	rxrpc_serial_t serial;
	222	int ret;
	223
	224	spin_lock_bh(&call->lock);
	225	if (call->conn)
	226	conn = rxrpc_get_connection_maybe(call->conn);
	227	spin_unlock_bh(&call->lock);
	228	if (!conn)
	229	return -ECONNRESET;
	230
	231	msg.msg_name = &call->peer->srx.transport;
	232	msg.msg_namelen = call->peer->srx.transport_len;
	233	msg.msg_control = NULL;
	234	msg.msg_controllen = 0;
	235	msg.msg_flags = 0;
	236
	237	pkt.whdr.epoch = htonl(conn->proto.epoch);
	238	pkt.whdr.cid = htonl(call->cid);
	239	pkt.whdr.callNumber = htonl(call->call_id);
	240	pkt.whdr.seq = 0;
	241	pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
	242	pkt.whdr.flags = conn->out_clientflag;
	243	pkt.whdr.userStatus = 0;
	244	pkt.whdr.securityIndex = call->security_ix;
	245	pkt.whdr._rsvd = 0;
	246	pkt.whdr.serviceId = htons(call->service_id);
	247	pkt.abort_code = htonl(call->abort_code);
	248
	249	iov[0].iov_base = &pkt;
	250	iov[0].iov_len = sizeof(pkt);
	251
	252	serial = atomic_inc_return(&conn->serial);
	253	pkt.whdr.serial = htonl(serial);
	254
	255	ret = kernel_sendmsg(conn->params.local->socket,
	256	&msg, iov, 1, sizeof(pkt));
	257
	258	rxrpc_put_connection(conn);
	259	return ret;
	260	}
	261
17926a79 DH	262	/*
	263	* send a packet through the transport endpoint
	264	*/
a1767077 DH	265	int rxrpc_send_data_packet(struct rxrpc_call call, struct sk_buff skb,
a1767077 DH	266	bool retrans)
17926a79	267	{
5a924b89 DH	268	struct rxrpc_connection *conn = call->conn;
	269	struct rxrpc_wire_header whdr;
	270	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
17926a79	271	struct msghdr msg;
5a924b89 DH	272	struct kvec iov[2];
	273	rxrpc_serial_t serial;
	274	size_t len;
a1767077	275	bool lost = false;
17926a79 DH	276	int ret, opt;
	277
	278	_enter(",{%d}", skb->len);
	279
5a924b89 DH	280	/* Each transmission of a Tx packet needs a new serial number */
5a924b89 DH	281	serial = atomic_inc_return(&conn->serial);
17926a79	282
5a924b89 DH	283	whdr.epoch = htonl(conn->proto.epoch);
	284	whdr.cid = htonl(call->cid);
	285	whdr.callNumber = htonl(call->call_id);
	286	whdr.seq = htonl(sp->hdr.seq);
	287	whdr.serial = htonl(serial);
	288	whdr.type = RXRPC_PACKET_TYPE_DATA;
	289	whdr.flags = sp->hdr.flags;
	290	whdr.userStatus = 0;
	291	whdr.securityIndex = call->security_ix;
	292	whdr._rsvd = htons(sp->hdr._rsvd);
	293	whdr.serviceId = htons(call->service_id);
	294
	295	iov[0].iov_base = &whdr;
	296	iov[0].iov_len = sizeof(whdr);
	297	iov[1].iov_base = skb->head;
	298	iov[1].iov_len = skb->len;
	299	len = iov[0].iov_len + iov[1].iov_len;
	300
	301	msg.msg_name = &call->peer->srx.transport;
	302	msg.msg_namelen = call->peer->srx.transport_len;
17926a79 DH	303	msg.msg_control = NULL;
	304	msg.msg_controllen = 0;
	305	msg.msg_flags = 0;
	306
57494343 DH	307	/* If our RTT cache needs working on, request an ACK. Also request
	308	* ACKs if a DATA packet appears to have been lost.
	309	*/
bf7d620a DH	310	if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
	311	(retrans \|\|
	312	call->cong_mode == RXRPC_CALL_SLOW_START \|\|
	313	(call->peer->rtt_usage < 3 && sp->hdr.seq & 1) \|\|
	314	ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
	315	ktime_get_real())))
0d4b103c DH	316	whdr.flags \|= RXRPC_REQUEST_ACK;
0d4b103c DH	317
8a681c36 DH	318	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
	319	static int lose;
	320	if ((lose++ & 7) == 7) {
a1767077 DH	321	ret = 0;
	322	lost = true;
	323	goto done;
8a681c36 DH	324	}
	325	}
	326
5a924b89 DH	327	_proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
5a924b89 DH	328
17926a79 DH	329	/* send the packet with the don't fragment bit set if we currently
17926a79 DH	330	* think it's small enough */
5a924b89 DH	331	if (iov[1].iov_len >= call->peer->maxdata)
	332	goto send_fragmentable;
	333
	334	down_read(&conn->params.local->defrag_sem);
	335	/* send the packet by UDP
	336	* - returns -EMSGSIZE if UDP would have to fragment the packet
	337	* to go out of the interface
	338	* - in which case, we'll have processed the ICMP error
	339	* message and update the peer record
	340	*/
	341	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
	342
	343	up_read(&conn->params.local->defrag_sem);
	344	if (ret == -EMSGSIZE)
	345	goto send_fragmentable;
	346
	347	done:
a1767077 DH	348	trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
a1767077 DH	349	retrans, lost);
50235c4b	350	if (ret >= 0) {
0d4b103c DH	351	ktime_t now = ktime_get_real();
0d4b103c DH	352	skb->tstamp = now;
50235c4b	353	smp_wmb();
5a924b89	354	sp->hdr.serial = serial;
0d4b103c DH	355	if (whdr.flags & RXRPC_REQUEST_ACK) {
0d4b103c DH	356	call->peer->rtt_last_req = now;
50235c4b	357	trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
0d4b103c	358	}
17926a79	359	}
5a924b89 DH	360	_leave(" = %d [%u]", ret, call->peer->maxdata);
5a924b89 DH	361	return ret;
17926a79 DH	362
	363	send_fragmentable:
	364	/* attempt to send this message with fragmentation enabled */
	365	_debug("send fragment");
	366
985a5c82 DH	367	down_write(&conn->params.local->defrag_sem);
	368
	369	switch (conn->params.local->srx.transport.family) {
	370	case AF_INET:
	371	opt = IP_PMTUDISC_DONT;
	372	ret = kernel_setsockopt(conn->params.local->socket,
	373	SOL_IP, IP_MTU_DISCOVER,
	374	(char *)&opt, sizeof(opt));
	375	if (ret == 0) {
5a924b89 DH	376	ret = kernel_sendmsg(conn->params.local->socket, &msg,
5a924b89 DH	377	iov, 2, len);
985a5c82 DH	378
	379	opt = IP_PMTUDISC_DO;
	380	kernel_setsockopt(conn->params.local->socket, SOL_IP,
	381	IP_MTU_DISCOVER,
	382	(char *)&opt, sizeof(opt));
	383	}
	384	break;
75b54cb5	385
d1912747	386	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	387	case AF_INET6:
	388	opt = IPV6_PMTUDISC_DONT;
	389	ret = kernel_setsockopt(conn->params.local->socket,
	390	SOL_IPV6, IPV6_MTU_DISCOVER,
	391	(char *)&opt, sizeof(opt));
	392	if (ret == 0) {
	393	ret = kernel_sendmsg(conn->params.local->socket, &msg,
	394	iov, 1, iov[0].iov_len);
	395
	396	opt = IPV6_PMTUDISC_DO;
	397	kernel_setsockopt(conn->params.local->socket,
	398	SOL_IPV6, IPV6_MTU_DISCOVER,
	399	(char *)&opt, sizeof(opt));
	400	}
	401	break;
d1912747	402	#endif
17926a79 DH	403	}
17926a79 DH	404
985a5c82	405	up_write(&conn->params.local->defrag_sem);
5a924b89	406	goto done;
17926a79	407	}
248f219c DH	408
	409	/*
	410	* reject packets through the local endpoint
	411	*/
	412	void rxrpc_reject_packets(struct rxrpc_local *local)
	413	{
1c2bc7b9	414	struct sockaddr_rxrpc srx;
248f219c DH	415	struct rxrpc_skb_priv *sp;
	416	struct rxrpc_wire_header whdr;
	417	struct sk_buff *skb;
	418	struct msghdr msg;
	419	struct kvec iov[2];
	420	size_t size;
	421	__be32 code;
	422
	423	_enter("%d", local->debug_id);
	424
	425	iov[0].iov_base = &whdr;
	426	iov[0].iov_len = sizeof(whdr);
	427	iov[1].iov_base = &code;
	428	iov[1].iov_len = sizeof(code);
	429	size = sizeof(whdr) + sizeof(code);
	430
1c2bc7b9	431	msg.msg_name = &srx.transport;
248f219c DH	432	msg.msg_control = NULL;
	433	msg.msg_controllen = 0;
	434	msg.msg_flags = 0;
	435
248f219c DH	436	memset(&whdr, 0, sizeof(whdr));
	437	whdr.type = RXRPC_PACKET_TYPE_ABORT;
	438
	439	while ((skb = skb_dequeue(&local->reject_queue))) {
71f3ca40	440	rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
248f219c	441	sp = rxrpc_skb(skb);
1c2bc7b9 DH	442
	443	if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
	444	msg.msg_namelen = srx.transport_len;
	445
248f219c DH	446	code = htonl(skb->priority);
	447
	448	whdr.epoch = htonl(sp->hdr.epoch);
	449	whdr.cid = htonl(sp->hdr.cid);
	450	whdr.callNumber = htonl(sp->hdr.callNumber);
	451	whdr.serviceId = htons(sp->hdr.serviceId);
	452	whdr.flags = sp->hdr.flags;
	453	whdr.flags ^= RXRPC_CLIENT_INITIATED;
	454	whdr.flags &= RXRPC_CLIENT_INITIATED;
	455
	456	kernel_sendmsg(local->socket, &msg, iov, 2, size);
248f219c DH	457	}
248f219c DH	458
71f3ca40	459	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
248f219c DH	460	}
	461
	462	_leave("");
	463	}