From 7c23f706733b12405c0cb8793866b57ba5800c98 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Thu, 6 May 2021 19:26:38 +0200
Subject: [PATCH] Fix various close-on-exec bugs.

---
 acceptor.cpp   | 2 +-
 client.cpp     | 2 +-
 httpinput.cpp  | 2 +-
 serverpool.cpp | 1 +
 stream.cpp     | 8 ++++++++
 udpinput.cpp   | 2 +-
 6 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/acceptor.cpp b/acceptor.cpp
index 2fef914..31901dd 100644
--- a/acceptor.cpp
+++ b/acceptor.cpp
@@ -104,7 +104,7 @@ Acceptor::Acceptor(const AcceptorProto &serialized)
 {
 	// Set back the close-on-exec flag for the socket.
 	// (This can't leak into a child, since we haven't been started yet.)
-	fcntl(server_sock, F_SETFD, 1);
+	fcntl(server_sock, F_SETFD, O_CLOEXEC);
 }
 
 AcceptorProto Acceptor::serialize() const
diff --git a/client.cpp b/client.cpp
index 26806d6..5d5c179 100644
--- a/client.cpp
+++ b/client.cpp
@@ -72,7 +72,7 @@ Client::Client(const ClientProto &serialized, const vector<shared_ptr<const stri
 {
 	// Set back the close-on-exec flag for the socket.
 	// (This can't leak into a child, since we haven't been started yet.)
-	fcntl(sock, F_SETFD, 1);
+	fcntl(sock, F_SETFD, O_CLOEXEC);
 
 	if (stream != nullptr) {
 		if (setsockopt(sock, SOL_SOCKET, SO_MAX_PACING_RATE, &stream->pacing_rate, sizeof(stream->pacing_rate)) == -1) {
diff --git a/httpinput.cpp b/httpinput.cpp
index 3a6b3c8..8d443c7 100644
--- a/httpinput.cpp
+++ b/httpinput.cpp
@@ -80,7 +80,7 @@ HTTPInput::HTTPInput(const InputProto &serialized)
 {
 	// Set back the close-on-exec flag for the socket.
 	// (This can't leak into a child, since we haven't been started yet.)
-	fcntl(sock, F_SETFD, 1);
+	fcntl(sock, F_SETFD, O_CLOEXEC);
 
 	pending_data.resize(serialized.pending_data().size());
 	memcpy(&pending_data[0], serialized.pending_data().data(), serialized.pending_data().size());
diff --git a/serverpool.cpp b/serverpool.cpp
index e9fea12..c7ff10c 100644
--- a/serverpool.cpp
+++ b/serverpool.cpp
@@ -1,4 +1,5 @@
 #include <assert.h>
+#include <fcntl.h>
 #include <stdlib.h>
 #include <sys/types.h>
 
diff --git a/stream.cpp b/stream.cpp
index 3ee1a43..4e5ca24 100644
--- a/stream.cpp
+++ b/stream.cpp
@@ -1,5 +1,6 @@
 #include <assert.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <inttypes.h>
 #include <limits.h>
 #include <math.h>
@@ -67,6 +68,9 @@ Stream::Stream(const StreamProto &serialized, int data_fd)
 		exit(1);
 	}
 
+	// Set the close-on-exec parameter back on the backlog fd.
+	fcntl(data_fd, F_SETFD, O_CLOEXEC);
+
 	for (ssize_t point : serialized.suitable_starting_point()) {
 		if (point == -1) {
 			// Can happen when upgrading from before 1.1.3,
@@ -103,6 +107,10 @@ StreamProto Stream::serialize()
 	serialized.set_first_fragment_index(first_fragment_index);
 	serialized.set_discontinuity_counter(discontinuity_counter);
 
+	// Unset the close-on-exec flag for the backlog fd.
+	// (This can't leak into a child, since there's only one thread left.)
+	fcntl(data_fd, F_SETFD, 0);
+
 	serialized.set_url(url);
 	data_fd = -1;
 	return serialized;
diff --git a/udpinput.cpp b/udpinput.cpp
index ecd099a..873b0b9 100644
--- a/udpinput.cpp
+++ b/udpinput.cpp
@@ -123,7 +123,7 @@ UDPInput::UDPInput(const InputProto &serialized)
 {
 	// Set back the close-on-exec flag for the socket.
 	// (This can't leak into a child, since we haven't been started yet.)
-	fcntl(sock, F_SETFD, 1);
+	fcntl(sock, F_SETFD, O_CLOEXEC);
 
 	// Should be verified by the caller.
 	string protocol;
-- 
2.39.2