rxrpc: Split client connection code out into its own file
Split the client-specific connection code out into its own file. It will
behave somewhat differently from the service-specific connection code, so
it makes sense to separate them.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index be437d5..9180164 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -33,7 +33,8 @@
* client conns away from the current allocation point to try and keep the IDs
* concentrated. We will also need to retire connections from an old epoch.
*/
-int rxrpc_get_client_connection_id(struct rxrpc_connection *conn, gfp_t gfp)
+static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn,
+ gfp_t gfp)
{
u32 epoch;
int id;
@@ -111,3 +112,248 @@
idr_destroy(&rxrpc_client_conn_ids);
}
+
+/*
+ * Allocate a client connection. The caller must take care to clear any
+ * padding bytes in *cp.
+ */
+static struct rxrpc_connection *
+rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp)
+{
+ struct rxrpc_connection *conn;
+ int ret;
+
+ _enter("");
+
+ conn = rxrpc_alloc_connection(gfp);
+ if (!conn) {
+ _leave(" = -ENOMEM");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ conn->params = *cp;
+ conn->proto.local = cp->local;
+ conn->proto.epoch = rxrpc_epoch;
+ conn->proto.cid = 0;
+ conn->proto.in_clientflag = 0;
+ conn->proto.family = cp->peer->srx.transport.family;
+ conn->out_clientflag = RXRPC_CLIENT_INITIATED;
+ conn->state = RXRPC_CONN_CLIENT;
+
+ switch (conn->proto.family) {
+ case AF_INET:
+ conn->proto.addr_size = sizeof(conn->proto.ipv4_addr);
+ conn->proto.ipv4_addr = cp->peer->srx.transport.sin.sin_addr;
+ conn->proto.port = cp->peer->srx.transport.sin.sin_port;
+ break;
+ }
+
+ ret = rxrpc_get_client_connection_id(conn, gfp);
+ if (ret < 0)
+ goto error_0;
+
+ ret = rxrpc_init_client_conn_security(conn);
+ if (ret < 0)
+ goto error_1;
+
+ ret = conn->security->prime_packet_security(conn);
+ if (ret < 0)
+ goto error_2;
+
+ write_lock(&rxrpc_connection_lock);
+ list_add_tail(&conn->link, &rxrpc_connections);
+ write_unlock(&rxrpc_connection_lock);
+
+ /* We steal the caller's peer ref. */
+ cp->peer = NULL;
+ rxrpc_get_local(conn->params.local);
+ key_get(conn->params.key);
+
+ _leave(" = %p", conn);
+ return conn;
+
+error_2:
+ conn->security->clear(conn);
+error_1:
+ rxrpc_put_client_connection_id(conn);
+error_0:
+ kfree(conn);
+ _leave(" = %d", ret);
+ return ERR_PTR(ret);
+}
+
+/*
+ * find a connection for a call
+ * - called in process context with IRQs enabled
+ */
+int rxrpc_connect_call(struct rxrpc_call *call,
+ struct rxrpc_conn_parameters *cp,
+ struct sockaddr_rxrpc *srx,
+ gfp_t gfp)
+{
+ struct rxrpc_connection *conn, *candidate = NULL;
+ struct rxrpc_local *local = cp->local;
+ struct rb_node *p, **pp, *parent;
+ long diff;
+ int chan;
+
+ DECLARE_WAITQUEUE(myself, current);
+
+ _enter("{%d,%lx},", call->debug_id, call->user_call_ID);
+
+ cp->peer = rxrpc_lookup_peer(cp->local, srx, gfp);
+ if (!cp->peer)
+ return -ENOMEM;
+
+ if (!cp->exclusive) {
+ /* Search for a existing client connection unless this is going
+ * to be a connection that's used exclusively for a single call.
+ */
+ _debug("search 1");
+ spin_lock(&local->client_conns_lock);
+ p = local->client_conns.rb_node;
+ while (p) {
+ conn = rb_entry(p, struct rxrpc_connection, client_node);
+
+#define cmp(X) ((long)conn->params.X - (long)cp->X)
+ diff = (cmp(peer) ?:
+ cmp(key) ?:
+ cmp(security_level));
+ if (diff < 0)
+ p = p->rb_left;
+ else if (diff > 0)
+ p = p->rb_right;
+ else
+ goto found_extant_conn;
+ }
+ spin_unlock(&local->client_conns_lock);
+ }
+
+ /* We didn't find a connection or we want an exclusive one. */
+ _debug("get new conn");
+ candidate = rxrpc_alloc_client_connection(cp, gfp);
+ if (!candidate) {
+ _leave(" = -ENOMEM");
+ return -ENOMEM;
+ }
+
+ if (cp->exclusive) {
+ /* Assign the call on an exclusive connection to channel 0 and
+ * don't add the connection to the endpoint's shareable conn
+ * lookup tree.
+ */
+ _debug("exclusive chan 0");
+ conn = candidate;
+ atomic_set(&conn->avail_chans, RXRPC_MAXCALLS - 1);
+ spin_lock(&conn->channel_lock);
+ chan = 0;
+ goto found_channel;
+ }
+
+ /* We need to redo the search before attempting to add a new connection
+ * lest we race with someone else adding a conflicting instance.
+ */
+ _debug("search 2");
+ spin_lock(&local->client_conns_lock);
+
+ pp = &local->client_conns.rb_node;
+ parent = NULL;
+ while (*pp) {
+ parent = *pp;
+ conn = rb_entry(parent, struct rxrpc_connection, client_node);
+
+ diff = (cmp(peer) ?:
+ cmp(key) ?:
+ cmp(security_level));
+ if (diff < 0)
+ pp = &(*pp)->rb_left;
+ else if (diff > 0)
+ pp = &(*pp)->rb_right;
+ else
+ goto found_extant_conn;
+ }
+
+ /* The second search also failed; simply add the new connection with
+ * the new call in channel 0. Note that we need to take the channel
+ * lock before dropping the client conn lock.
+ */
+ _debug("new conn");
+ conn = candidate;
+ candidate = NULL;
+
+ rb_link_node(&conn->client_node, parent, pp);
+ rb_insert_color(&conn->client_node, &local->client_conns);
+
+ atomic_set(&conn->avail_chans, RXRPC_MAXCALLS - 1);
+ spin_lock(&conn->channel_lock);
+ spin_unlock(&local->client_conns_lock);
+ chan = 0;
+
+found_channel:
+ _debug("found chan");
+ call->conn = conn;
+ call->channel = chan;
+ call->epoch = conn->proto.epoch;
+ call->cid = conn->proto.cid | chan;
+ call->call_id = ++conn->channels[chan].call_counter;
+ conn->channels[chan].call_id = call->call_id;
+ rcu_assign_pointer(conn->channels[chan].call, call);
+
+ _net("CONNECT call %d on conn %d", call->debug_id, conn->debug_id);
+
+ spin_unlock(&conn->channel_lock);
+ rxrpc_put_peer(cp->peer);
+ cp->peer = NULL;
+ _leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
+ return 0;
+
+ /* We found a suitable connection already in existence. Discard any
+ * candidate we may have allocated, and try to get a channel on this
+ * one.
+ */
+found_extant_conn:
+ _debug("found conn");
+ rxrpc_get_connection(conn);
+ spin_unlock(&local->client_conns_lock);
+
+ rxrpc_put_connection(candidate);
+
+ if (!atomic_add_unless(&conn->avail_chans, -1, 0)) {
+ if (!gfpflags_allow_blocking(gfp)) {
+ rxrpc_put_connection(conn);
+ _leave(" = -EAGAIN");
+ return -EAGAIN;
+ }
+
+ add_wait_queue(&conn->channel_wq, &myself);
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (atomic_add_unless(&conn->avail_chans, -1, 0))
+ break;
+ if (signal_pending(current))
+ goto interrupted;
+ schedule();
+ }
+ remove_wait_queue(&conn->channel_wq, &myself);
+ __set_current_state(TASK_RUNNING);
+ }
+
+ /* The connection allegedly now has a free channel and we can now
+ * attach the call to it.
+ */
+ spin_lock(&conn->channel_lock);
+
+ for (chan = 0; chan < RXRPC_MAXCALLS; chan++)
+ if (!conn->channels[chan].call)
+ goto found_channel;
+ BUG();
+
+interrupted:
+ remove_wait_queue(&conn->channel_wq, &myself);
+ __set_current_state(TASK_RUNNING);
+ rxrpc_put_connection(conn);
+ rxrpc_put_peer(cp->peer);
+ cp->peer = NULL;
+ _leave(" = -ERESTARTSYS");
+ return -ERESTARTSYS;
+}