/* 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 (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);
_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);
