コード例 #1
0
ファイル: call_accept.c プロジェクト: gxt/linux
/*
 * generate a connection-level abort
 */
static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx,
		      struct rxrpc_wire_header *whdr)
{
	struct msghdr msg;
	struct kvec iov[1];
	size_t len;
	int ret;

	_enter("%d,,", local->debug_id);

	whdr->type	= RXRPC_PACKET_TYPE_BUSY;
	whdr->serial	= htonl(1);

	msg.msg_name	= &srx->transport.sin;
	msg.msg_namelen	= sizeof(srx->transport.sin);
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	iov[0].iov_base	= whdr;
	iov[0].iov_len	= sizeof(*whdr);

	len = iov[0].iov_len;

	_proto("Tx BUSY %%1");

	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
	if (ret < 0) {
		_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
		return -EAGAIN;
	}

	_leave(" = 0");
	return 0;
}
コード例 #2
0
ファイル: local_event.c プロジェクト: ReneNyffenegger/linux
/*
 * Process event packets targetted at a local endpoint.
 */
void rxrpc_process_local_events(struct rxrpc_local *local)
{
	struct sk_buff *skb;
	char v;

	_enter("");

	skb = skb_dequeue(&local->event_queue);
	if (skb) {
		struct rxrpc_skb_priv *sp = rxrpc_skb(skb);

		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
		_debug("{%d},{%u}", local->debug_id, sp->hdr.type);

		switch (sp->hdr.type) {
		case RXRPC_PACKET_TYPE_VERSION:
			if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
					  &v, 1) < 0)
				return;
			_proto("Rx VERSION { %02x }", v);
			if (v == 0)
				rxrpc_send_version_request(local, &sp->hdr, skb);
			break;

		default:
			/* Just ignore anything we don't understand */
			break;
		}

		rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
	}

	_leave("");
}
コード例 #3
0
/*
 * connection-level Rx packet processor
 */
static int rxrpc_process_event(struct rxrpc_connection *conn,
			       struct sk_buff *skb,
			       u32 *_abort_code)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	__be32 wtmp;
	u32 abort_code;
	int loop, ret;

	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
		kleave(" = -ECONNABORTED [%u]", conn->state);
		return -ECONNABORTED;
	}

	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);

	switch (sp->hdr.type) {
	case RXRPC_PACKET_TYPE_ABORT:
		if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
			return -EPROTO;
		abort_code = ntohl(wtmp);
		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);

		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
				  abort_code);
		return -ECONNABORTED;

	case RXRPC_PACKET_TYPE_CHALLENGE:
		return conn->security->respond_to_challenge(conn, skb,
							    _abort_code);

	case RXRPC_PACKET_TYPE_RESPONSE:
		ret = conn->security->verify_response(conn, skb, _abort_code);
		if (ret < 0)
			return ret;

		ret = conn->security->init_connection_security(conn);
		if (ret < 0)
			return ret;

		conn->security->prime_packet_security(conn);
		read_lock_bh(&conn->lock);
		spin_lock(&conn->state_lock);

		if (conn->state == RXRPC_CONN_SERVER_CHALLENGING) {
			conn->state = RXRPC_CONN_SERVER;
			for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
				rxrpc_call_is_secure(conn->channels[loop]);
		}

		spin_unlock(&conn->state_lock);
		read_unlock_bh(&conn->lock);
		return 0;

	default:
		_leave(" = -EPROTO [%u]", sp->hdr.type);
		return -EPROTO;
	}
}
コード例 #4
0
ファイル: local_event.c プロジェクト: krzk/linux
/*
 * Reply to a version request
 */
static void rxrpc_send_version_request(struct rxrpc_local *local,
				       struct rxrpc_host_header *hdr,
				       struct sk_buff *skb)
{
	struct rxrpc_wire_header whdr;
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	struct sockaddr_rxrpc srx;
	struct msghdr msg;
	struct kvec iov[2];
	size_t len;
	int ret;

	_enter("");

	if (rxrpc_extract_addr_from_skb(local, &srx, skb) < 0)
		return;

	msg.msg_name	= &srx.transport;
	msg.msg_namelen	= srx.transport_len;
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	whdr.epoch	= htonl(sp->hdr.epoch);
	whdr.cid	= htonl(sp->hdr.cid);
	whdr.callNumber	= htonl(sp->hdr.callNumber);
	whdr.seq	= 0;
	whdr.serial	= 0;
	whdr.type	= RXRPC_PACKET_TYPE_VERSION;
	whdr.flags	= RXRPC_LAST_PACKET | (~hdr->flags & RXRPC_CLIENT_INITIATED);
	whdr.userStatus	= 0;
	whdr.securityIndex = 0;
	whdr._rsvd	= 0;
	whdr.serviceId	= htons(sp->hdr.serviceId);

	iov[0].iov_base	= &whdr;
	iov[0].iov_len	= sizeof(whdr);
	iov[1].iov_base	= (char *)rxrpc_version_string;
	iov[1].iov_len	= sizeof(rxrpc_version_string);

	len = iov[0].iov_len + iov[1].iov_len;

	_proto("Tx VERSION (reply)");

	ret = kernel_sendmsg(local->socket, &msg, iov, 2, len);
	if (ret < 0)
		trace_rxrpc_tx_fail(local->debug_id, 0, ret,
				    rxrpc_tx_fail_version_reply);

	_leave("");
}
コード例 #5
0
ファイル: conn_event.c プロジェクト: guribe94/linux
/*
 * connection-level Rx packet processor
 */
static int rxrpc_process_event(struct rxrpc_connection *conn,
			       struct sk_buff *skb,
			       u32 *_abort_code)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	__be32 wtmp;
	u32 abort_code;
	int loop, ret;

	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
		_leave(" = -ECONNABORTED [%u]", conn->state);
		return -ECONNABORTED;
	}

	_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_call(conn, skb,
					   sp->hdr.cid & RXRPC_CHANNELMASK);
		return 0;

	case RXRPC_PACKET_TYPE_BUSY:
		/* Just ignore BUSY packets for now. */
		return 0;

	case RXRPC_PACKET_TYPE_ABORT:
		if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
				  &wtmp, sizeof(wtmp)) < 0) {
			trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
					      tracepoint_string("bad_abort"));
			return -EPROTO;
		}
		abort_code = ntohl(wtmp);
		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);

		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
				  abort_code, -ECONNABORTED);
		return -ECONNABORTED;

	case RXRPC_PACKET_TYPE_CHALLENGE:
		return conn->security->respond_to_challenge(conn, skb,
							    _abort_code);

	case RXRPC_PACKET_TYPE_RESPONSE:
		ret = conn->security->verify_response(conn, skb, _abort_code);
		if (ret < 0)
			return ret;

		ret = conn->security->init_connection_security(conn);
		if (ret < 0)
			return ret;

		ret = conn->security->prime_packet_security(conn);
		if (ret < 0)
			return ret;

		spin_lock(&conn->channel_lock);
		spin_lock(&conn->state_lock);

		if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
			conn->state = RXRPC_CONN_SERVICE;
			spin_unlock(&conn->state_lock);
			for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
				rxrpc_call_is_secure(
					rcu_dereference_protected(
						conn->channels[loop].call,
						lockdep_is_held(&conn->channel_lock)));
		} else {
			spin_unlock(&conn->state_lock);
		}

		spin_unlock(&conn->channel_lock);
		return 0;

	default:
		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
				      tracepoint_string("bad_conn_pkt"));
		return -EPROTO;
	}
}
コード例 #6
0
ファイル: conn_event.c プロジェクト: guribe94/linux
/*
 * Retransmit terminal ACK or ABORT of the previous call.
 */
static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
				       struct sk_buff *skb,
				       unsigned int channel)
{
	struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
	struct rxrpc_channel *chan;
	struct msghdr msg;
	struct kvec iov[3];
	struct {
		struct rxrpc_wire_header whdr;
		union {
			__be32 abort_code;
			struct rxrpc_ackpacket ack;
		};
	} __attribute__((packed)) pkt;
	struct rxrpc_ackinfo ack_info;
	size_t len;
	int ret, ioc;
	u32 serial, mtu, call_id, padding;

	_enter("%d", conn->debug_id);

	chan = &conn->channels[channel];

	/* 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 (skb && 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;

	iov[0].iov_base	= &pkt;
	iov[0].iov_len	= sizeof(pkt.whdr);
	iov[1].iov_base	= &padding;
	iov[1].iov_len	= 3;
	iov[2].iov_base	= &ack_info;
	iov[2].iov_len	= sizeof(ack_info);

	pkt.whdr.epoch		= htonl(conn->proto.epoch);
	pkt.whdr.cid		= htonl(conn->proto.cid | channel);
	pkt.whdr.callNumber	= htonl(call_id);
	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(conn->service_id);

	len = sizeof(pkt.whdr);
	switch (chan->last_type) {
	case RXRPC_PACKET_TYPE_ABORT:
		pkt.abort_code	= htonl(chan->last_abort);
		iov[0].iov_len += sizeof(pkt.abort_code);
		len += sizeof(pkt.abort_code);
		ioc = 1;
		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 ? skb->priority : 0);
		pkt.ack.firstPacket	= htonl(chan->last_seq + 1);
		pkt.ack.previousPacket	= htonl(chan->last_seq);
		pkt.ack.serial		= htonl(skb ? sp->hdr.serial : 0);
		pkt.ack.reason		= skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
		pkt.ack.nAcks		= 0;
		ack_info.rxMTU		= htonl(rxrpc_rx_mtu);
		ack_info.maxMTU		= htonl(mtu);
		ack_info.rwind		= htonl(rxrpc_rx_window_size);
		ack_info.jumbo_max	= htonl(rxrpc_rx_jumbo_max);
		pkt.whdr.flags		|= RXRPC_SLOW_START_OK;
		padding			= 0;
		iov[0].iov_len += sizeof(pkt.ack);
		len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
		ioc = 3;
		break;

	default:
		return;
	}

	/* 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;

	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:
		trace_rxrpc_tx_ack(chan->call_debug_id, serial,
				   ntohl(pkt.ack.firstPacket),
				   ntohl(pkt.ack.serial),
				   pkt.ack.reason, 0);
		_proto("Tx ACK %%%u [re]", serial);
		break;
	}

	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
	conn->params.peer->last_tx_at = ktime_get_seconds();
	if (ret < 0)
		trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
				    rxrpc_tx_point_call_final_resend);
	else
		trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
				      rxrpc_tx_point_call_final_resend);

	_leave("");
}
コード例 #7
0
ファイル: conn_event.c プロジェクト: guribe94/linux
/*
 * generate a connection-level abort
 */
static int rxrpc_abort_connection(struct rxrpc_connection *conn,
				  int error, u32 abort_code)
{
	struct rxrpc_wire_header whdr;
	struct msghdr msg;
	struct kvec iov[2];
	__be32 word;
	size_t len;
	u32 serial;
	int ret;

	_enter("%d,,%u,%u", conn->debug_id, error, abort_code);

	/* generate a connection-level abort */
	spin_lock_bh(&conn->state_lock);
	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
		spin_unlock_bh(&conn->state_lock);
		_leave(" = 0 [already dead]");
		return 0;
	}

	conn->state = RXRPC_CONN_LOCALLY_ABORTED;
	spin_unlock_bh(&conn->state_lock);

	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error);

	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;

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

	word		= htonl(conn->local_abort);

	iov[0].iov_base	= &whdr;
	iov[0].iov_len	= sizeof(whdr);
	iov[1].iov_base	= &word;
	iov[1].iov_len	= sizeof(word);

	len = iov[0].iov_len + iov[1].iov_len;

	serial = atomic_inc_return(&conn->serial);
	whdr.serial = htonl(serial);
	_proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);

	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
	if (ret < 0) {
		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
				    rxrpc_tx_point_conn_abort);
		_debug("sendmsg failed: %d", ret);
		return -EAGAIN;
	}

	trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);

	conn->params.peer->last_tx_at = ktime_get_seconds();

	_leave(" = 0");
	return 0;
}
コード例 #8
0
ファイル: ar-output.c プロジェクト: 325116067/semc-qsd8x50
/*
 * queue a packet for transmission, set the resend timer and attempt
 * to send the packet immediately
 */
static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
			       bool last)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	int ret;

	_net("queue skb %p [%d]", skb, call->acks_head);

	ASSERT(call->acks_window != NULL);
	call->acks_window[call->acks_head] = (unsigned long) skb;
	smp_wmb();
	call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);

	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
		_debug("________awaiting reply/ACK__________");
		write_lock_bh(&call->state_lock);
		switch (call->state) {
		case RXRPC_CALL_CLIENT_SEND_REQUEST:
			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
			break;
		case RXRPC_CALL_SERVER_ACK_REQUEST:
			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
			if (!last)
				break;
		case RXRPC_CALL_SERVER_SEND_REPLY:
			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
			break;
		default:
			break;
		}
		write_unlock_bh(&call->state_lock);
	}

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

	sp->need_resend = 0;
	sp->resend_at = jiffies + rxrpc_resend_timeout * HZ;
	if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
		_debug("run timer");
		call->resend_timer.expires = sp->resend_at;
		add_timer(&call->resend_timer);
	}

	/* attempt to cancel the rx-ACK timer, deferring reply transmission if
	 * we're ACK'ing the request phase of an incoming call */
	ret = -EAGAIN;
	if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
		/* the packet may be freed by rxrpc_process_call() before this
		 * returns */
		ret = rxrpc_send_packet(call->conn->trans, skb);
		_net("sent skb %p", skb);
	} else {
		_debug("failed to delete ACK timer");
	}

	if (ret < 0) {
		_debug("need instant resend %d", ret);
		sp->need_resend = 1;
		rxrpc_instant_resend(call);
	}

	_leave("");
}
コード例 #9
0
static int rxrpc_abort_connection(struct rxrpc_connection *conn,
				  u32 error, u32 abort_code)
{
	struct rxrpc_header hdr;
	struct msghdr msg;
	struct kvec iov[2];
	__be32 word;
	size_t len;
	int ret;

	_enter("%d,,%u,%u", conn->debug_id, error, abort_code);

	/* generate a connection-level abort */
	spin_lock_bh(&conn->state_lock);
	if (conn->state < RXRPC_CONN_REMOTELY_ABORTED) {
		conn->state = RXRPC_CONN_LOCALLY_ABORTED;
		conn->error = error;
		spin_unlock_bh(&conn->state_lock);
	} else {
		spin_unlock_bh(&conn->state_lock);
		_leave(" = 0 [already dead]");
		return 0;
	}

	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code);

	msg.msg_name	= &conn->trans->peer->srx.transport.sin;
	msg.msg_namelen	= sizeof(conn->trans->peer->srx.transport.sin);
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	hdr.epoch	= conn->epoch;
	hdr.cid		= conn->cid;
	hdr.callNumber	= 0;
	hdr.seq		= 0;
	hdr.type	= RXRPC_PACKET_TYPE_ABORT;
	hdr.flags	= conn->out_clientflag;
	hdr.userStatus	= 0;
	hdr.securityIndex = conn->security_ix;
	hdr._rsvd	= 0;
	hdr.serviceId	= conn->service_id;

	word = htonl(abort_code);

	iov[0].iov_base	= &hdr;
	iov[0].iov_len	= sizeof(hdr);
	iov[1].iov_base	= &word;
	iov[1].iov_len	= sizeof(word);

	len = iov[0].iov_len + iov[1].iov_len;

	hdr.serial = htonl(atomic_inc_return(&conn->serial));
	_proto("Tx CONN ABORT %%%u { %d }", ntohl(hdr.serial), abort_code);

	ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
	if (ret < 0) {
		_debug("sendmsg failed: %d", ret);
		return -EAGAIN;
	}

	_leave(" = 0");
	return 0;
}
コード例 #10
0
ファイル: output.c プロジェクト: AshishNamdev/linux
/*
 * 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;
}