Initial import

1 files changed, 510 insertions, 0 deletions

diff --git a/net/rxrpc/ar-accept.c b/net/rxrpc/ar-accept.c
new file mode 100644
index 000000000..6d79310fc
--- /dev/null
+++ b/net/rxrpc/ar-accept.c
@@ -0,0 +1,510 @@
+/* incoming call handling
+ *
+ * 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/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/gfp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+/*
+ * generate a connection-level abort
+ */
+static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx,
+		      struct rxrpc_header *hdr)
+{
+	struct msghdr msg;
+	struct kvec iov[1];
+	size_t len;
+	int ret;
+
+	_enter("%d,,", local->debug_id);
+
+	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;
+
+	hdr->seq	= 0;
+	hdr->type	= RXRPC_PACKET_TYPE_BUSY;
+	hdr->flags	= 0;
+	hdr->userStatus	= 0;
+	hdr->_rsvd	= 0;
+
+	iov[0].iov_base	= hdr;
+	iov[0].iov_len	= sizeof(*hdr);
+
+	len = iov[0].iov_len;
+
+	hdr->serial = htonl(1);
+	_proto("Tx BUSY %%%u", ntohl(hdr->serial));
+
+	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
+	if (ret < 0) {
+		_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
+		return -EAGAIN;
+	}
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * accept an incoming call that needs peer, transport and/or connection setting
+ * up
+ */
+static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
+				      struct rxrpc_sock *rx,
+				      struct sk_buff *skb,
+				      struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_transport *trans;
+	struct rxrpc_skb_priv *sp, *nsp;
+	struct rxrpc_peer *peer;
+	struct rxrpc_call *call;
+	struct sk_buff *notification;
+	int ret;
+
+	_enter("");
+
+	sp = rxrpc_skb(skb);
+
+	/* get a notification message to send to the server app */
+	notification = alloc_skb(0, GFP_NOFS);
+	if (!notification) {
+		_debug("no memory");
+		ret = -ENOMEM;
+		goto error_nofree;
+	}
+	rxrpc_new_skb(notification);
+	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
+
+	peer = rxrpc_get_peer(srx, GFP_NOIO);
+	if (IS_ERR(peer)) {
+		_debug("no peer");
+		ret = -EBUSY;
+		goto error;
+	}
+
+	trans = rxrpc_get_transport(local, peer, GFP_NOIO);
+	rxrpc_put_peer(peer);
+	if (IS_ERR(trans)) {
+		_debug("no trans");
+		ret = -EBUSY;
+		goto error;
+	}
+
+	conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
+	rxrpc_put_transport(trans);
+	if (IS_ERR(conn)) {
+		_debug("no conn");
+		ret = PTR_ERR(conn);
+		goto error;
+	}
+
+	call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
+	rxrpc_put_connection(conn);
+	if (IS_ERR(call)) {
+		_debug("no call");
+		ret = PTR_ERR(call);
+		goto error;
+	}
+
+	/* attach the call to the socket */
+	read_lock_bh(&local->services_lock);
+	if (rx->sk.sk_state == RXRPC_CLOSE)
+		goto invalid_service;
+
+	write_lock(&rx->call_lock);
+	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
+		rxrpc_get_call(call);
+
+		spin_lock(&call->conn->state_lock);
+		if (sp->hdr.securityIndex > 0 &&
+		    call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
+			_debug("await conn sec");
+			list_add_tail(&call->accept_link, &rx->secureq);
+			call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
+			atomic_inc(&call->conn->usage);
+			set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
+			rxrpc_queue_conn(call->conn);
+		} else {
+			_debug("conn ready");
+			call->state = RXRPC_CALL_SERVER_ACCEPTING;
+			list_add_tail(&call->accept_link, &rx->acceptq);
+			rxrpc_get_call(call);
+			nsp = rxrpc_skb(notification);
+			nsp->call = call;
+
+			ASSERTCMP(atomic_read(&call->usage), >=, 3);
+
+			_debug("notify");
+			spin_lock(&call->lock);
+			ret = rxrpc_queue_rcv_skb(call, notification, true,
+						  false);
+			spin_unlock(&call->lock);
+			notification = NULL;
+			BUG_ON(ret < 0);
+		}
+		spin_unlock(&call->conn->state_lock);
+
+		_debug("queued");
+	}
+	write_unlock(&rx->call_lock);
+
+	_debug("process");
+	rxrpc_fast_process_packet(call, skb);
+
+	_debug("done");
+	read_unlock_bh(&local->services_lock);
+	rxrpc_free_skb(notification);
+	rxrpc_put_call(call);
+	_leave(" = 0");
+	return 0;
+
+invalid_service:
+	_debug("invalid");
+	read_unlock_bh(&local->services_lock);
+
+	read_lock_bh(&call->state_lock);
+	if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
+	    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
+		rxrpc_get_call(call);
+		rxrpc_queue_call(call);
+	}
+	read_unlock_bh(&call->state_lock);
+	rxrpc_put_call(call);
+	ret = -ECONNREFUSED;
+error:
+	rxrpc_free_skb(notification);
+error_nofree:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * accept incoming calls that need peer, transport and/or connection setting up
+ * - the packets we get are all incoming client DATA packets that have seq == 1
+ */
+void rxrpc_accept_incoming_calls(struct work_struct *work)
+{
+	struct rxrpc_local *local =
+		container_of(work, struct rxrpc_local, acceptor);
+	struct rxrpc_skb_priv *sp;
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_sock *rx;
+	struct sk_buff *skb;
+	__be16 service_id;
+	int ret;
+
+	_enter("%d", local->debug_id);
+
+	read_lock_bh(&rxrpc_local_lock);
+	if (atomic_read(&local->usage) > 0)
+		rxrpc_get_local(local);
+	else
+		local = NULL;
+	read_unlock_bh(&rxrpc_local_lock);
+	if (!local) {
+		_leave(" [local dead]");
+		return;
+	}
+
+process_next_packet:
+	skb = skb_dequeue(&local->accept_queue);
+	if (!skb) {
+		rxrpc_put_local(local);
+		_leave("\n");
+		return;
+	}
+
+	_net("incoming call skb %p", skb);
+
+	sp = rxrpc_skb(skb);
+
+	/* determine the remote address */
+	memset(&srx, 0, sizeof(srx));
+	srx.srx_family = AF_RXRPC;
+	srx.transport.family = local->srx.transport.family;
+	srx.transport_type = local->srx.transport_type;
+	switch (srx.transport.family) {
+	case AF_INET:
+		srx.transport_len = sizeof(struct sockaddr_in);
+		srx.transport.sin.sin_port = udp_hdr(skb)->source;
+		srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
+		break;
+	default:
+		goto busy;
+	}
+
+	/* get the socket providing the service */
+	service_id = sp->hdr.serviceId;
+	read_lock_bh(&local->services_lock);
+	list_for_each_entry(rx, &local->services, listen_link) {
+		if (rx->service_id == service_id &&
+		    rx->sk.sk_state != RXRPC_CLOSE)
+			goto found_service;
+	}
+	read_unlock_bh(&local->services_lock);
+	goto invalid_service;
+
+found_service:
+	_debug("found service %hd", ntohs(rx->service_id));
+	if (sk_acceptq_is_full(&rx->sk))
+		goto backlog_full;
+	sk_acceptq_added(&rx->sk);
+	sock_hold(&rx->sk);
+	read_unlock_bh(&local->services_lock);
+
+	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
+	if (ret < 0)
+		sk_acceptq_removed(&rx->sk);
+	sock_put(&rx->sk);
+	switch (ret) {
+	case -ECONNRESET: /* old calls are ignored */
+	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
+	case 0:
+		goto process_next_packet;
+	case -ECONNREFUSED:
+		goto invalid_service;
+	case -EBUSY:
+		goto busy;
+	case -EKEYREJECTED:
+		goto security_mismatch;
+	default:
+		BUG();
+	}
+
+backlog_full:
+	read_unlock_bh(&local->services_lock);
+busy:
+	rxrpc_busy(local, &srx, &sp->hdr);
+	rxrpc_free_skb(skb);
+	goto process_next_packet;
+
+invalid_service:
+	skb->priority = RX_INVALID_OPERATION;
+	rxrpc_reject_packet(local, skb);
+	goto process_next_packet;
+
+	/* can't change connection security type mid-flow */
+security_mismatch:
+	skb->priority = RX_PROTOCOL_ERROR;
+	rxrpc_reject_packet(local, skb);
+	goto process_next_packet;
+}
+
+/*
+ * handle acceptance of a call by userspace
+ * - assign the user call ID to the call at the front of the queue
+ */
+struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
+				     unsigned long user_call_ID)
+{
+	struct rxrpc_call *call;
+	struct rb_node *parent, **pp;
+	int ret;
+
+	_enter(",%lx", user_call_ID);
+
+	ASSERT(!irqs_disabled());
+
+	write_lock(&rx->call_lock);
+
+	ret = -ENODATA;
+	if (list_empty(&rx->acceptq))
+		goto out;
+
+	/* check the user ID isn't already in use */
+	ret = -EBADSLT;
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		call = rb_entry(parent, struct rxrpc_call, sock_node);
+
+		if (user_call_ID < call->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (user_call_ID > call->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto out;
+	}
+
+	/* dequeue the first call and check it's still valid */
+	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
+	list_del_init(&call->accept_link);
+	sk_acceptq_removed(&rx->sk);
+
+	write_lock_bh(&call->state_lock);
+	switch (call->state) {
+	case RXRPC_CALL_SERVER_ACCEPTING:
+		call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
+		break;
+	case RXRPC_CALL_REMOTELY_ABORTED:
+	case RXRPC_CALL_LOCALLY_ABORTED:
+		ret = -ECONNABORTED;
+		goto out_release;
+	case RXRPC_CALL_NETWORK_ERROR:
+		ret = call->conn->error;
+		goto out_release;
+	case RXRPC_CALL_DEAD:
+		ret = -ETIME;
+		goto out_discard;
+	default:
+		BUG();
+	}
+
+	/* formalise the acceptance */
+	call->user_call_ID = user_call_ID;
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
+		BUG();
+	if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
+		BUG();
+	rxrpc_queue_call(call);
+
+	rxrpc_get_call(call);
+	write_unlock_bh(&call->state_lock);
+	write_unlock(&rx->call_lock);
+	_leave(" = %p{%d}", call, call->debug_id);
+	return call;
+
+	/* if the call is already dying or dead, then we leave the socket's ref
+	 * on it to be released by rxrpc_dead_call_expired() as induced by
+	 * rxrpc_release_call() */
+out_release:
+	_debug("release %p", call);
+	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+	    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
+		rxrpc_queue_call(call);
+out_discard:
+	write_unlock_bh(&call->state_lock);
+	_debug("discard %p", call);
+out:
+	write_unlock(&rx->call_lock);
+	_leave(" = %d", ret);
+	return ERR_PTR(ret);
+}
+
+/*
+ * handle rejectance of a call by userspace
+ * - reject the call at the front of the queue
+ */
+int rxrpc_reject_call(struct rxrpc_sock *rx)
+{
+	struct rxrpc_call *call;
+	int ret;
+
+	_enter("");
+
+	ASSERT(!irqs_disabled());
+
+	write_lock(&rx->call_lock);
+
+	ret = -ENODATA;
+	if (list_empty(&rx->acceptq))
+		goto out;
+
+	/* dequeue the first call and check it's still valid */
+	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
+	list_del_init(&call->accept_link);
+	sk_acceptq_removed(&rx->sk);
+
+	write_lock_bh(&call->state_lock);
+	switch (call->state) {
+	case RXRPC_CALL_SERVER_ACCEPTING:
+		call->state = RXRPC_CALL_SERVER_BUSY;
+		if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
+			rxrpc_queue_call(call);
+		ret = 0;
+		goto out_release;
+	case RXRPC_CALL_REMOTELY_ABORTED:
+	case RXRPC_CALL_LOCALLY_ABORTED:
+		ret = -ECONNABORTED;
+		goto out_release;
+	case RXRPC_CALL_NETWORK_ERROR:
+		ret = call->conn->error;
+		goto out_release;
+	case RXRPC_CALL_DEAD:
+		ret = -ETIME;
+		goto out_discard;
+	default:
+		BUG();
+	}
+
+	/* if the call is already dying or dead, then we leave the socket's ref
+	 * on it to be released by rxrpc_dead_call_expired() as induced by
+	 * rxrpc_release_call() */
+out_release:
+	_debug("release %p", call);
+	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+	    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
+		rxrpc_queue_call(call);
+out_discard:
+	write_unlock_bh(&call->state_lock);
+	_debug("discard %p", call);
+out:
+	write_unlock(&rx->call_lock);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
+ * @sock: The socket on which the impending call is waiting
+ * @user_call_ID: The tag to attach to the call
+ *
+ * Allow a kernel service to accept an incoming call, assuming the incoming
+ * call is still valid.
+ */
+struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock,
+					    unsigned long user_call_ID)
+{
+	struct rxrpc_call *call;
+
+	_enter(",%lx", user_call_ID);
+	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
+	_leave(" = %p", call);
+	return call;
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_accept_call);
+
+/**
+ * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
+ * @sock: The socket on which the impending call is waiting
+ *
+ * Allow a kernel service to reject an incoming call with a BUSY message,
+ * assuming the incoming call is still valid.
+ */
+int rxrpc_kernel_reject_call(struct socket *sock)
+{
+	int ret;
+
+	_enter("");
+	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
+	_leave(" = %d", ret);
+	return ret;
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_reject_call);