Check fd in reconnect

Change-Id: Ibc0f4d96b5c0a385d8fedbc1acd23898f1cbea46
Signed-off-by: Takamasa Takenaka <takamasa.takenaka@windriver.com>

fm-common/sources/fmAPI.cpp

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2017 Wind River Systems, Inc.
+// Copyright (c) 2017,2023 Wind River Systems, Inc.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -106,6 +106,18 @@ static bool dequeue(fm_buff_t &req) {
 static bool fm_lib_reconnect() {
   char addr[INET6_ADDRSTRLEN];
 
+  if (m_connected) {
+    // Check fd is valid
+    // When fm manager is restarted, it is possible to
+    // have broken pipe. This checks fd is valid or not.
+    // If not, set m_connected false, so that it will
+    // try to connect in the following while loop.
+    if (!m_client.fd_valid()) {
+      FM_WARNING_LOG("Invalid fd. Try to reconnect...");
+      m_connected = false;
+    }
+  }
+
   while (!m_connected) {
     struct addrinfo hints;
     struct addrinfo *result = NULL, *rp;

fm-common/sources/fmSocket.cpp

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2017 Wind River Systems, Inc.
+// Copyright (c) 2017,2023 Wind River Systems, Inc.
 //
 // SPDX-License-Identifier: Apache-2.0
 //
@@ -10,6 +10,7 @@
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <stdlib.h>
+#include <sys/poll.h>
 #include <sys/select.h>
 #include <errno.h>
 #include <unistd.h>
@@ -259,6 +260,21 @@ int CFmSocket::select_read(int fd,int timeout, bool &timedout){
 	return select(&fd,1,NULL,0,timeout,0,timedout);
 }
 
+bool CFmSocket::fd_valid(){
+	struct pollfd pfd = {.fd = m_fd, .events = POLLRDHUP};
+	if ((poll(&pfd, 1, 0)) < 0) {
+		return false;
+	} else {
+		if (pfd.revents & POLLRDHUP) {
+			// broken pipe
+			FM_ERROR_LOG("It is broken pipe\n");
+			return false;
+		} else {
+			return true;
+		}
+	}
+}
+
 bool CFmSocket::recvfrom(void *data, long &len, CFmSockAddr &addr) {
 	socklen_t addr_len = sizeof(addr.address);
 	int l = ::recvfrom(m_fd,data,len,0,addr.get_sockaddr(),&addr_len);

fm-common/sources/fmSocket.h

@@ -67,6 +67,7 @@ public:
 
 
 	int get_fd() { return m_fd; }
+	bool fd_valid();
 	bool recvfrom(void *data, long &len, CFmSockAddr &addr );
 
 	static int select(int *rfd, int rlen, int *wfds, int wlen,int timeout,int timeoutusec, bool &timedout);