From 2ce99fe4bf22054fbdac84c3a7bb3c31582a00c0 Mon Sep 17 00:00:00 2001
From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Wed, 19 Jan 2022 15:46:11 +0100
Subject: [PATCH] MINOR: quic: create accept queue for QUIC connections

Create a new type quic_accept_queue to handle QUIC connections accept.
A queue will be allocated for each thread. It contains a list of
listeners which contains at least one quic_conn ready to be accepted and
the tasklet to run listener_accept for these listeners.
---
 include/haproxy/quic_sock-t.h | 12 +++++++
 include/haproxy/quic_sock.h   |  1 +
 src/proto_quic.c              |  1 +
 src/quic_sock.c               | 64 +++++++++++++++++++++++++++++++++++
 4 files changed, 78 insertions(+)
 create mode 100644 include/haproxy/quic_sock-t.h

diff --git a/include/haproxy/quic_sock-t.h b/include/haproxy/quic_sock-t.h
new file mode 100644
index 000000000..5a591ccd5
--- /dev/null
+++ b/include/haproxy/quic_sock-t.h
@@ -0,0 +1,12 @@
+#ifndef _HAPROXY_QUIC_SOCK_T_H
+#define _HAPROXY_QUIC_SOCK_T_H
+#ifdef USE_QUIC
+
+/* QUIC connection accept queue. One per thread. */
+struct quic_accept_queue {
+	struct mt_list listeners; /* QUIC listeners with at least one connection ready to be accepted on this queue */
+	struct tasklet *tasklet;  /* task responsible to call listener_accept */
+};
+
+#endif /* USE_QUIC */
+#endif /* _HAPROXY_QUIC_SOCK_T_H */
diff --git a/include/haproxy/quic_sock.h b/include/haproxy/quic_sock.h
index 652bc414b..2a2818bc5 100644
--- a/include/haproxy/quic_sock.h
+++ b/include/haproxy/quic_sock.h
@@ -32,6 +32,7 @@
 #include <haproxy/api.h>
 #include <haproxy/connection-t.h>
 #include <haproxy/listener-t.h>
+#include <haproxy/quic_sock-t.h>
 
 int quic_session_accept(struct connection *cli_conn);
 int quic_sock_accepting_conn(const struct receiver *rx);
diff --git a/src/proto_quic.c b/src/proto_quic.c
index 6fdb3f779..dc3d26219 100644
--- a/src/proto_quic.c
+++ b/src/proto_quic.c
@@ -525,6 +525,7 @@ static void quic_add_listener(struct protocol *proto, struct listener *listener)
 	listener->rx.cids = EB_ROOT_UNIQUE;
 	listener->rx.flags |= RX_F_LOCAL_ACCEPT;
 	HA_RWLOCK_INIT(&listener->rx.cids_lock);
+
 	default_add_listener(proto, listener);
 }
 
diff --git a/src/quic_sock.c b/src/quic_sock.c
index bb593738e..866eaa287 100644
--- a/src/quic_sock.c
+++ b/src/quic_sock.c
@@ -222,3 +222,67 @@ void quic_sock_fd_iocb(int fd)
  out:
 	MT_LIST_APPEND(&l->rx.rxbuf_list, &rxbuf->mt_list);
 }
+
+
+/*********************** QUIC accept queue management ***********************/
+/* per-thread accept queues */
+struct quic_accept_queue *quic_accept_queues;
+
+/* Tasklet handler to accept QUIC connections. Call listener_accept on every
+ * listener instances registered in the accept queue.
+ */
+static struct task *quic_accept_run(struct task *t, void *ctx, unsigned int i)
+{
+	struct li_per_thread *lthr;
+	struct mt_list *elt1, elt2;
+	struct quic_accept_queue *queue = &quic_accept_queues[tid];
+
+	mt_list_for_each_entry_safe(lthr, &queue->listeners, quic_accept.list, elt1, elt2) {
+		listener_accept(lthr->li);
+		MT_LIST_DELETE_SAFE(elt1);
+	}
+
+	return NULL;
+}
+
+static int quic_alloc_accept_queues(void)
+{
+	int i;
+
+	quic_accept_queues = calloc(global.nbthread, sizeof(struct quic_accept_queue));
+	if (!quic_accept_queues) {
+		ha_alert("Failed to allocate the quic accept queues.\n");
+		return 0;
+	}
+
+	for (i = 0; i < global.nbthread; ++i) {
+		struct tasklet *task;
+		if (!(task = tasklet_new())) {
+			ha_alert("Failed to allocate the quic accept queue on thread %d.\n", i);
+			return 0;
+		}
+
+		tasklet_set_tid(task, i);
+		task->process = quic_accept_run;
+		quic_accept_queues[i].tasklet = task;
+
+		MT_LIST_INIT(&quic_accept_queues[i].listeners);
+	}
+
+	return 1;
+}
+REGISTER_POST_CHECK(quic_alloc_accept_queues);
+
+static int quic_deallocate_accept_queues(void)
+{
+	int i;
+
+	if (quic_accept_queues) {
+		for (i = 0; i < global.nbthread; ++i)
+			tasklet_free(quic_accept_queues[i].tasklet);
+		free(quic_accept_queues);
+	}
+
+	return 1;
+}
+REGISTER_POST_DEINIT(quic_deallocate_accept_queues);