/*
* 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");
}
/*
* Allocate a new incoming call from the prealloc pool, along with a connection
* and a peer as necessary.
*/
static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
struct rxrpc_local *local,
struct rxrpc_connection *conn,
struct sk_buff *skb)
{
struct rxrpc_backlog *b = rx->backlog;
struct rxrpc_peer *peer, *xpeer;
struct rxrpc_call *call;
unsigned short call_head, conn_head, peer_head;
unsigned short call_tail, conn_tail, peer_tail;
unsigned short call_count, conn_count;
/* #calls >= #conns >= #peers must hold true. */
call_head = smp_load_acquire(&b->call_backlog_head);
call_tail = b->call_backlog_tail;
call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
conn_head = smp_load_acquire(&b->conn_backlog_head);
conn_tail = b->conn_backlog_tail;
conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
ASSERTCMP(conn_count, >=, call_count);
peer_head = smp_load_acquire(&b->peer_backlog_head);
peer_tail = b->peer_backlog_tail;
ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
conn_count);
if (call_count == 0)
return NULL;
if (!conn) {
/* No connection. We're going to need a peer to start off
* with. If one doesn't yet exist, use a spare from the
* preallocation set. We dump the address into the spare in
* anticipation - and to save on stack space.
*/
xpeer = b->peer_backlog[peer_tail];
if (rxrpc_extract_addr_from_skb(&xpeer->srx, skb) < 0)
return NULL;
peer = rxrpc_lookup_incoming_peer(local, xpeer);
if (peer == xpeer) {
b->peer_backlog[peer_tail] = NULL;
smp_store_release(&b->peer_backlog_tail,
(peer_tail + 1) &
(RXRPC_BACKLOG_MAX - 1));
}
/* Now allocate and set up the connection */
conn = b->conn_backlog[conn_tail];
b->conn_backlog[conn_tail] = NULL;
smp_store_release(&b->conn_backlog_tail,
(conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
rxrpc_get_local(local);
conn->params.local = local;
conn->params.peer = peer;
rxrpc_see_connection(conn);
rxrpc_new_incoming_connection(rx, conn, skb);
} else {
rxrpc_get_connection(conn);
}
/* And now we can allocate and set up a new call */
call = b->call_backlog[call_tail];
b->call_backlog[call_tail] = NULL;
smp_store_release(&b->call_backlog_tail,
(call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
rxrpc_see_call(call);
call->conn = conn;
call->peer = rxrpc_get_peer(conn->params.peer);
call->cong_cwnd = call->peer->cong_cwnd;
return call;
}
