From 0c9d9f21633c5dbb482893a9d6bdf40111829925 Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Sun, 7 Aug 2022 23:04:46 +0100
Subject: [PATCH] Don't set SIGPIPE to ignore, use MSG_NOSIGNAL instead.

Closes #2564. Thanks to nmeum.
---
 ChangeLog.txt   | 1 +
 lib/mosquitto.c | 4 ----
 lib/net_mosq.c  | 6 +-----
 lib/net_mosq.h  | 5 +++++
 4 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index c5618b5d..70557603 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -21,6 +21,7 @@ Client library:
   cmake version to 3.1, which is still ancient.
 - Fix use of `MOSQ_OPT_TLS_ENGINE` being unable to be used due to the openssl
   ctx not being initialised until starting to connect. Closes #2537.
+- Don't set SIGPIPE to ignore, use MSG_NOSIGNAL instead. Closes #2564.
 
 Clients:
 - Fix mosquitto_pub incorrectly reusing topic aliases when reconnecting.
diff --git a/lib/mosquitto.c b/lib/mosquitto.c
index 0d68d313..72762ed6 100644
--- a/lib/mosquitto.c
+++ b/lib/mosquitto.c
@@ -109,10 +109,6 @@ struct mosquitto *mosquitto_new(const char *id, bool clean_start, void *userdata
 		return NULL;
 	}
 
-#ifndef WIN32
-	signal(SIGPIPE, SIG_IGN);
-#endif
-
 	mosq = (struct mosquitto *)mosquitto__calloc(1, sizeof(struct mosquitto));
 	if(mosq){
 		mosq->sock = INVALID_SOCKET;
diff --git a/lib/net_mosq.c b/lib/net_mosq.c
index 22f5a313..d4eb89ef 100644
--- a/lib/net_mosq.c
+++ b/lib/net_mosq.c
@@ -1041,11 +1041,7 @@ ssize_t net__write(struct mosquitto *mosq, const void *buf, size_t count)
 		/* Call normal write/send */
 #endif
 
-#ifndef WIN32
-	return write(mosq->sock, buf, count);
-#else
-	return send(mosq->sock, buf, count, 0);
-#endif
+	return send(mosq->sock, buf, count, MSG_NOSIGNAL);
 
 #ifdef WITH_TLS
 	}
diff --git a/lib/net_mosq.h b/lib/net_mosq.h
index 37a21461..ded98760 100644
--- a/lib/net_mosq.h
+++ b/lib/net_mosq.h
@@ -19,6 +19,7 @@ Contributors:
 #define NET_MOSQ_H
 
 #ifndef WIN32
+#  include <sys/socket.h>
 #  include <unistd.h>
 #else
 #  include <winsock2.h>
@@ -51,6 +52,10 @@ typedef SSIZE_T ssize_t;
 #define INVALID_SOCKET -1
 #endif
 
+#ifndef MSG_NOSIGNAL
+#  define MSG_NOSIGNAL 0
+#endif
+
 /* Macros for accessing the MSB and LSB of a uint16_t */
 #define MOSQ_MSB(A) (uint8_t)((A & 0xFF00) >> 8)
 #define MOSQ_LSB(A) (uint8_t)(A & 0x00FF)