1 files changed, 658 insertions, 0 deletions

diff --git a/net/rxrpc/ar-output.c b/net/rxrpc/ar-output.c
new file mode 100644
index 0000000..67aa951
--- /dev/null
+++ b/net/rxrpc/ar-output.c
@@ -0,0 +1,658 @@
+/* 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.
+ */
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+int rxrpc_resend_timeout = 4;
+
+static int rxrpc_send_data(struct kiocb *iocb,
+			   struct rxrpc_sock *rx,
+			   struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len);
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+			      unsigned long *user_call_ID,
+			      enum rxrpc_command *command,
+			      u32 *abort_code,
+			      bool server)
+{
+	struct cmsghdr *cmsg;
+	int len;
+
+	*command = RXRPC_CMD_SEND_DATA;
+
+	if (msg->msg_controllen == 0)
+		return -EINVAL;
+
+	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+
+		len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+		_debug("CMSG %d, %d, %d",
+		       cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+		if (cmsg->cmsg_level != SOL_RXRPC)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case RXRPC_USER_CALL_ID:
+			if (msg->msg_flags & MSG_CMSG_COMPAT) {
+				if (len != sizeof(u32))
+					return -EINVAL;
+				*user_call_ID = *(u32 *) CMSG_DATA(cmsg);
+			} else {
+				if (len != sizeof(unsigned long))
+					return -EINVAL;
+				*user_call_ID = *(unsigned long *)
+					CMSG_DATA(cmsg);
+			}
+			_debug("User Call ID %lx", *user_call_ID);
+			break;
+
+		case RXRPC_ABORT:
+			if (*command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			*command = RXRPC_CMD_SEND_ABORT;
+			if (len != sizeof(*abort_code))
+				return -EINVAL;
+			*abort_code = *(unsigned int *) CMSG_DATA(cmsg);
+			_debug("Abort %x", *abort_code);
+			if (*abort_code == 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_ACCEPT:
+			if (*command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			*command = RXRPC_CMD_ACCEPT;
+			if (len != 0)
+				return -EINVAL;
+			if (!server)
+				return -EISCONN;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * abort a call, sending an ABORT packet to the peer
+ */
+static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
+{
+	write_lock_bh(&call->state_lock);
+
+	if (call->state <= RXRPC_CALL_COMPLETE) {
+		call->state = RXRPC_CALL_LOCALLY_ABORTED;
+		call->abort_code = abort_code;
+		set_bit(RXRPC_CALL_ABORT, &call->events);
+		del_timer_sync(&call->resend_timer);
+		del_timer_sync(&call->ack_timer);
+		clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+		clear_bit(RXRPC_CALL_ACK, &call->events);
+		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+		schedule_work(&call->processor);
+	}
+
+	write_unlock_bh(&call->state_lock);
+}
+
+/*
+ * send a message forming part of a client call through an RxRPC socket
+ * - caller holds the socket locked
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_client_sendmsg(struct kiocb *iocb, struct rxrpc_sock *rx,
+			 struct rxrpc_transport *trans, struct msghdr *msg,
+			 size_t len)
+{
+	struct rxrpc_conn_bundle *bundle;
+	enum rxrpc_command cmd;
+	struct rxrpc_call *call;
+	unsigned long user_call_ID = 0;
+	struct key *key;
+	__be16 service_id;
+	u32 abort_code = 0;
+	int ret;
+
+	_enter("");
+
+	ASSERT(trans != NULL);
+
+	ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
+				 false);
+	if (ret < 0)
+		return ret;
+
+	bundle = NULL;
+	if (trans) {
+		service_id = rx->service_id;
+		if (msg->msg_name) {
+			struct sockaddr_rxrpc *srx =
+				(struct sockaddr_rxrpc *) msg->msg_name;
+			service_id = htons(srx->srx_service);
+		}
+		key = rx->key;
+		if (key && !rx->key->payload.data)
+			key = NULL;
+		bundle = rxrpc_get_bundle(rx, trans, key, service_id,
+					  GFP_KERNEL);
+		if (IS_ERR(bundle))
+			return PTR_ERR(bundle);
+	}
+
+	call = rxrpc_get_client_call(rx, trans, bundle, user_call_ID,
+				     abort_code == 0, GFP_KERNEL);
+	if (trans)
+		rxrpc_put_bundle(trans, bundle);
+	if (IS_ERR(call)) {
+		_leave(" = %ld", PTR_ERR(call));
+		return PTR_ERR(call);
+	}
+
+	_debug("CALL %d USR %lx ST %d on CONN %p",
+	       call->debug_id, call->user_call_ID, call->state, call->conn);
+
+	if (call->state >= RXRPC_CALL_COMPLETE) {
+		/* it's too late for this call */
+		ret = -ESHUTDOWN;
+	} else if (cmd == RXRPC_CMD_SEND_ABORT) {
+		rxrpc_send_abort(call, abort_code);
+	} else if (cmd != RXRPC_CMD_SEND_DATA) {
+		ret = -EINVAL;
+	} else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
+		/* request phase complete for this client call */
+		ret = -EPROTO;
+	} else {
+		ret = rxrpc_send_data(iocb, rx, call, msg, len);
+	}
+
+	rxrpc_put_call(call);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * send a message through a server socket
+ * - caller holds the socket locked
+ */
+int rxrpc_server_sendmsg(struct kiocb *iocb, struct rxrpc_sock *rx,
+			 struct msghdr *msg, size_t len)
+{
+	enum rxrpc_command cmd;
+	struct rxrpc_call *call;
+	unsigned long user_call_ID = 0;
+	u32 abort_code = 0;
+	int ret;
+
+	_enter("");
+
+	ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
+				 true);
+	if (ret < 0)
+		return ret;
+
+	if (cmd == RXRPC_CMD_ACCEPT)
+		return rxrpc_accept_call(rx, user_call_ID);
+
+	call = rxrpc_find_server_call(rx, user_call_ID);
+	if (!call)
+		return -EBADSLT;
+	if (call->state >= RXRPC_CALL_COMPLETE) {
+		ret = -ESHUTDOWN;
+		goto out;
+	}
+
+	switch (cmd) {
+	case RXRPC_CMD_SEND_DATA:
+		if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+		    call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+		    call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+			/* Tx phase not yet begun for this call */
+			ret = -EPROTO;
+			break;
+		}
+
+		ret = rxrpc_send_data(iocb, rx, call, msg, len);
+		break;
+
+	case RXRPC_CMD_SEND_ABORT:
+		rxrpc_send_abort(call, abort_code);
+		break;
+	default:
+		BUG();
+	}
+
+	out:
+	rxrpc_put_call(call);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * send a packet through the transport endpoint
+ */
+int rxrpc_send_packet(struct rxrpc_transport *trans, struct sk_buff *skb)
+{
+	struct kvec iov[1];
+	struct msghdr msg;
+	int ret, opt;
+
+	_enter(",{%d}", skb->len);
+
+	iov[0].iov_base = skb->head;
+	iov[0].iov_len = skb->len;
+
+	msg.msg_name = &trans->peer->srx.transport.sin;
+	msg.msg_namelen = sizeof(trans->peer->srx.transport.sin);
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags = 0;
+
+	/* send the packet with the don't fragment bit set if we currently
+	 * think it's small enough */
+	if (skb->len - sizeof(struct rxrpc_header) < trans->peer->maxdata) {
+		down_read(&trans->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(trans->local->socket, &msg, iov, 1,
+				     iov[0].iov_len);
+
+		up_read(&trans->local->defrag_sem);
+		if (ret == -EMSGSIZE)
+			goto send_fragmentable;
+
+		_leave(" = %d [%u]", ret, trans->peer->maxdata);
+		return ret;
+	}
+
+send_fragmentable:
+	/* attempt to send this message with fragmentation enabled */
+	_debug("send fragment");
+
+	down_write(&trans->local->defrag_sem);
+	opt = IP_PMTUDISC_DONT;
+	ret = kernel_setsockopt(trans->local->socket, SOL_IP, IP_MTU_DISCOVER,
+				(char *) &opt, sizeof(opt));
+	if (ret == 0) {
+		ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
+				     iov[0].iov_len);
+
+		opt = IP_PMTUDISC_DO;
+		kernel_setsockopt(trans->local->socket, SOL_IP,
+				  IP_MTU_DISCOVER, (char *) &opt, sizeof(opt));
+	}
+
+	up_write(&trans->local->defrag_sem);
+	_leave(" = %d [frag %u]", ret, trans->peer->maxdata);
+	return ret;
+}
+
+/*
+ * wait for space to appear in the transmit/ACK window
+ * - caller holds the socket locked
+ */
+static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
+				    struct rxrpc_call *call,
+				    long *timeo)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret;
+
+	_enter(",{%d},%ld",
+	       CIRC_SPACE(call->acks_head, call->acks_tail, call->acks_winsz),
+	       *timeo);
+
+	add_wait_queue(&call->tx_waitq, &myself);
+
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		ret = 0;
+		if (CIRC_SPACE(call->acks_head, call->acks_tail,
+			       call->acks_winsz) > 0)
+			break;
+		if (signal_pending(current)) {
+			ret = sock_intr_errno(*timeo);
+			break;
+		}
+
+		release_sock(&rx->sk);
+		*timeo = schedule_timeout(*timeo);
+		lock_sock(&rx->sk);
+	}
+
+	remove_wait_queue(&call->tx_waitq, &myself);
+	set_current_state(TASK_RUNNING);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * attempt to schedule an instant Tx resend
+ */
+static inline void rxrpc_instant_resend(struct rxrpc_call *call)
+{
+	read_lock_bh(&call->state_lock);
+	if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
+		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+		if (call->state < RXRPC_CALL_COMPLETE &&
+		    !test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
+			schedule_work(&call->processor);
+	}
+	read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * 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("");
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - caller holds the socket locked
+ */
+static int rxrpc_send_data(struct kiocb *iocb,
+			   struct rxrpc_sock *rx,
+			   struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len)
+{
+	struct rxrpc_skb_priv *sp;
+	unsigned char __user *from;
+	struct sk_buff *skb;
+	struct iovec *iov;
+	struct sock *sk = &rx->sk;
+	long timeo;
+	bool more;
+	int ret, ioc, segment, copied;
+
+	_enter(",,,{%zu},%zu", msg->msg_iovlen, len);
+
+	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+	/* this should be in poll */
+	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+		return -EPIPE;
+
+	iov = msg->msg_iov;
+	ioc = msg->msg_iovlen - 1;
+	from = iov->iov_base;
+	segment = iov->iov_len;
+	iov++;
+	more = msg->msg_flags & MSG_MORE;
+
+	skb = call->tx_pending;
+	call->tx_pending = NULL;
+
+	copied = 0;
+	do {
+		int copy;
+
+		if (segment > len)
+			segment = len;
+
+		_debug("SEGMENT %d @%p", segment, from);
+
+		if (!skb) {
+			size_t size, chunk, max, space;
+
+			_debug("alloc");
+
+			if (CIRC_SPACE(call->acks_head, call->acks_tail,
+				       call->acks_winsz) <= 0) {
+				ret = -EAGAIN;
+				if (msg->msg_flags & MSG_DONTWAIT)
+					goto maybe_error;
+				ret = rxrpc_wait_for_tx_window(rx, call,
+							       &timeo);
+				if (ret < 0)
+					goto maybe_error;
+			}
+
+			max = call->conn->trans->peer->maxdata;
+			max -= call->conn->security_size;
+			max &= ~(call->conn->size_align - 1UL);
+
+			chunk = max;
+			if (chunk > len)
+				chunk = len;
+
+			space = chunk + call->conn->size_align;
+			space &= ~(call->conn->size_align - 1UL);
+
+			size = space + call->conn->header_size;
+
+			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
+
+			/* create a buffer that we can retain until it's ACK'd */
+			skb = sock_alloc_send_skb(
+				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
+			if (!skb)
+				goto maybe_error;
+
+			rxrpc_new_skb(skb);
+
+			_debug("ALLOC SEND %p", skb);
+
+			ASSERTCMP(skb->mark, ==, 0);
+
+			_debug("HS: %u", call->conn->header_size);
+			skb_reserve(skb, call->conn->header_size);
+			skb->len += call->conn->header_size;
+
+			sp = rxrpc_skb(skb);
+			sp->remain = chunk;
+			if (sp->remain > skb_tailroom(skb))
+				sp->remain = skb_tailroom(skb);
+
+			_net("skb: hr %d, tr %d, hl %d, rm %d",
+			       skb_headroom(skb),
+			       skb_tailroom(skb),
+			       skb_headlen(skb),
+			       sp->remain);
+
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		}
+
+		_debug("append");
+		sp = rxrpc_skb(skb);
+
+		/* append next segment of data to the current buffer */
+		copy = skb_tailroom(skb);
+		ASSERTCMP(copy, >, 0);
+		if (copy > segment)
+			copy = segment;
+		if (copy > sp->remain)
+			copy = sp->remain;
+
+		_debug("add");
+		ret = skb_add_data(skb, from, copy);
+		_debug("added");
+		if (ret < 0)
+			goto efault;
+		sp->remain -= copy;
+		skb->mark += copy;
+
+		len -= copy;
+		segment -= copy;
+		from += copy;
+		while (segment == 0 && ioc > 0) {
+			from = iov->iov_base;
+			segment = iov->iov_len;
+			iov++;
+			ioc--;
+		}
+		if (len == 0) {
+			segment = 0;
+			ioc = 0;
+		}
+
+		/* check for the far side aborting the call or a network error
+		 * occurring */
+		if (call->state > RXRPC_CALL_COMPLETE)
+			goto call_aborted;
+
+		/* add the packet to the send queue if it's now full */
+		if (sp->remain <= 0 || (segment == 0 && !more)) {
+			struct rxrpc_connection *conn = call->conn;
+			size_t pad;
+
+			/* pad out if we're using security */
+			if (conn->security) {
+				pad = conn->security_size + skb->mark;
+				pad = conn->size_align - pad;
+				pad &= conn->size_align - 1;
+				_debug("pad %zu", pad);
+				if (pad)
+					memset(skb_put(skb, pad), 0, pad);
+			}
+
+			sp->hdr.epoch = conn->epoch;
+			sp->hdr.cid = call->cid;
+			sp->hdr.callNumber = call->call_id;
+			sp->hdr.seq =
+				htonl(atomic_inc_return(&call->sequence));
+			sp->hdr.serial =
+				htonl(atomic_inc_return(&conn->serial));
+			sp->hdr.type = RXRPC_PACKET_TYPE_DATA;
+			sp->hdr.userStatus = 0;
+			sp->hdr.securityIndex = conn->security_ix;
+			sp->hdr._rsvd = 0;
+			sp->hdr.serviceId = conn->service_id;
+
+			sp->hdr.flags = conn->out_clientflag;
+			if (len == 0 && !more)
+				sp->hdr.flags |= RXRPC_LAST_PACKET;
+			else if (CIRC_SPACE(call->acks_head, call->acks_tail,
+					    call->acks_winsz) > 1)
+				sp->hdr.flags |= RXRPC_MORE_PACKETS;
+
+			ret = rxrpc_secure_packet(
+				call, skb, skb->mark,
+				skb->head + sizeof(struct rxrpc_header));
+			if (ret < 0)
+				goto out;
+
+			memcpy(skb->head, &sp->hdr,
+			       sizeof(struct rxrpc_header));
+			rxrpc_queue_packet(call, skb, segment == 0 && !more);
+			skb = NULL;
+		}
+
+	} while (segment > 0);
+
+out:
+	call->tx_pending = skb;
+	_leave(" = %d", ret);
+	return ret;
+
+call_aborted:
+	rxrpc_free_skb(skb);
+	if (call->state == RXRPC_CALL_NETWORK_ERROR)
+		ret = call->conn->trans->peer->net_error;
+	else
+		ret = -ECONNABORTED;
+	_leave(" = %d", ret);
+	return ret;
+
+maybe_error:
+	if (copied)
+		ret = copied;
+	goto out;
+
+efault:
+	ret = -EFAULT;
+	goto out;
+}