From a4380b211f629237e7ccf22d30bb76ad091ad5f3 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Wed, 4 Nov 2020 13:59:04 +0100
Subject: [PATCH] MEDIUM: listeners: make use of fd_want_recv_safe() to enable
 early receivers

We used to refrain from calling fd_want_recv() if fd_updt was not allocated
but it's not the right solution as this does not allow the FD to be set.
Instead, let's use the new fd_want_recv_safe() which will update the FD and
create an update entry only if possible. In addition, the equivalent test
before calling fd_stop_recv() was removed as totally useless since there's
not fd_updt creation in this case.
---
 src/proto_sockpair.c | 10 ++++------
 src/proto_tcp.c      | 10 ++++------
 src/proto_udp.c      | 10 ++++------
 src/proto_uxst.c     | 10 ++++------
 src/sock.c           | 14 +++++---------
 5 files changed, 21 insertions(+), 33 deletions(-)

diff --git a/src/proto_sockpair.c b/src/proto_sockpair.c
index f8e673d0b..cc9275379 100644
--- a/src/proto_sockpair.c
+++ b/src/proto_sockpair.c
@@ -107,21 +107,19 @@ static void sockpair_add_listener(struct listener *listener, int port)
 }
 
 /* Enable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void sockpair_enable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_want_recv(l->rx.fd);
+	fd_want_recv_safe(l->rx.fd);
 }
 
 /* Disable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void sockpair_disable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_stop_recv(l->rx.fd);
+	fd_stop_recv(l->rx.fd);
 }
 
 /* Binds receiver <rx>, and assigns rx->iocb and rx->owner as the callback
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index e59aa961c..06adf9b47 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -749,21 +749,19 @@ static void tcpv6_add_listener(struct listener *listener, int port)
 }
 
 /* Enable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void tcp_enable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_want_recv(l->rx.fd);
+	fd_want_recv_safe(l->rx.fd);
 }
 
 /* Disable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void tcp_disable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_stop_recv(l->rx.fd);
+	fd_stop_recv(l->rx.fd);
 }
 
 /* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver
diff --git a/src/proto_udp.c b/src/proto_udp.c
index 0724680a9..ae5562afb 100644
--- a/src/proto_udp.c
+++ b/src/proto_udp.c
@@ -173,21 +173,19 @@ static void udp6_add_listener(struct listener *listener, int port)
 }
 
 /* Enable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void udp_enable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_want_recv(l->rx.fd);
+	fd_want_recv_safe(l->rx.fd);
 }
 
 /* Disable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void udp_disable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_stop_recv(l->rx.fd);
+	fd_stop_recv(l->rx.fd);
 }
 
 /* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver
diff --git a/src/proto_uxst.c b/src/proto_uxst.c
index d33f8c3a7..f558e5f34 100644
--- a/src/proto_uxst.c
+++ b/src/proto_uxst.c
@@ -153,21 +153,19 @@ static void uxst_add_listener(struct listener *listener, int port)
 }
 
 /* Enable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void uxst_enable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_want_recv(l->rx.fd);
+	fd_want_recv_safe(l->rx.fd);
 }
 
 /* Disable receipt of incoming connections for listener <l>. The receiver must
- * still be valid. Does nothing in early boot (needs fd_updt).
+ * still be valid.
  */
 static void uxst_disable_listener(struct listener *l)
 {
-	if (fd_updt)
-		fd_stop_recv(l->rx.fd);
+	fd_stop_recv(l->rx.fd);
 }
 
 /* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver
diff --git a/src/sock.c b/src/sock.c
index 192559bfb..3e2f20887 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -186,21 +186,17 @@ int sock_create_server_socket(struct connection *conn)
 	return my_socketat(ns, conn->dst->ss_family, SOCK_STREAM, 0);
 }
 
-/* Enables receiving on receiver <rx> once already bound. Does nothing in early
- * boot (needs fd_updt).
- */
+/* Enables receiving on receiver <rx> once already bound. */
 void sock_enable(struct receiver *rx)
 {
-        if (rx->flags & RX_F_BOUND && fd_updt)
-		fd_want_recv(rx->fd);
+        if (rx->flags & RX_F_BOUND)
+		fd_want_recv_safe(rx->fd);
 }
 
-/* Disables receiving on receiver <rx> once already bound. Does nothing in early
- * boot (needs fd_updt).
- */
+/* Disables receiving on receiver <rx> once already bound. */
 void sock_disable(struct receiver *rx)
 {
-        if (rx->flags & RX_F_BOUND && fd_updt)
+        if (rx->flags & RX_F_BOUND)
 		fd_stop_recv(rx->fd);
 }