1 files changed, 504 insertions, 0 deletions

diff --git a/net/rxrpc/ar-accept.c b/net/rxrpc/ar-accept.c
new file mode 100644
index 000000000000..92a87fde8bfe
--- /dev/null
+++ b/net/rxrpc/ar-accept.c
@@ -0,0 +1,504 @@
+/* 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 <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);
+        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 (!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;
+                        if (ret < 0)
+                                BUG();
+                }
+                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);
+        _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);