Add close-on-exec flag to open(), socket(), accept() & fopen().

configure.cmake

@@ -315,6 +315,7 @@ ENDIF()
 #
 # Tests for functions
 #
+CHECK_FUNCTION_EXISTS (accept4 HAVE_ACCEPT4)
 CHECK_FUNCTION_EXISTS (access HAVE_ACCESS)
 #CHECK_FUNCTION_EXISTS (aiowait HAVE_AIOWAIT)
 CHECK_FUNCTION_EXISTS (aio_read HAVE_AIO_READ)

include/my_global.h

@@ -609,6 +609,12 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #ifndef O_NOFOLLOW
 #define O_NOFOLLOW      0
 #endif
+#ifndef O_CLOEXEC
+#define O_CLOEXEC       0
+#endif
+#ifndef SOCK_CLOEXEC
+#define SOCK_CLOEXEC    0
+#endif
 
 /* additional file share flags for win32 */
 #ifdef __WIN__

include/mysql/psi/mysql_socket.h

@@ -553,7 +553,7 @@ inline_mysql_socket_socket
   int domain, int type, int protocol)
 {
   MYSQL_SOCKET mysql_socket= MYSQL_INVALID_SOCKET;
-  mysql_socket.fd= socket(domain, type, protocol);
+  mysql_socket.fd= socket(domain, type | SOCK_CLOEXEC, protocol);
 
 #ifdef HAVE_PSI_SOCKET_INTERFACE
   if (likely(mysql_socket.fd != INVALID_SOCKET))
@@ -1013,6 +1013,8 @@ inline_mysql_socket_accept
 #endif
   MYSQL_SOCKET socket_listen, struct sockaddr *addr, socklen_t *addr_len)
 {
+  int flags;
+
   MYSQL_SOCKET socket_accept= MYSQL_INVALID_SOCKET;
   socklen_t addr_length= (addr_len != NULL) ? *addr_len : 0;
 
@@ -1026,7 +1028,17 @@ inline_mysql_socket_accept
       (&state, socket_listen.m_psi, PSI_SOCKET_CONNECT, (size_t)0, src_file, src_line);
 
     /* Instrumented code */
+#ifdef HAVE_ACCEPT4
+    socket_accept.fd= accept4(socket_listen.fd, addr, &addr_length,
+                              SOCK_CLOEXEC);
+#else
     socket_accept.fd= accept(socket_listen.fd, addr, &addr_length);
+    flags= fcntl(socket_accept.fd, F_GETFD);
+    if (flags != -1) {
+      flags |= FD_CLOEXEC;
+      fcntl(socket_accept.fd, F_SETFD, flags);
+    }
+#endif
 
     /* Instrumentation end */
     if (locker != NULL)
@@ -1036,7 +1048,17 @@ inline_mysql_socket_accept
 #endif
   {
     /* Non instrumented code */
+#ifdef HAVE_ACCEPT4
+    socket_accept.fd= accept4(socket_listen.fd, addr, &addr_length,
+                              SOCK_CLOEXEC);
+#else
     socket_accept.fd= accept(socket_listen.fd, addr, &addr_length);
+    flags= fcntl(socket_accept.fd, F_GETFD);
+    if (flags != -1) {
+      flags |= FD_CLOEXEC;
+      fcntl(socket_accept.fd, F_SETFD, flags);
+    }
+#endif
   }
 
 #ifdef HAVE_PSI_SOCKET_INTERFACE

mysys/my_create.c

@@ -43,7 +43,7 @@ File my_create(const char *FileName, int CreateFlags, int access_flags,
 #if defined(_WIN32)
   fd= my_win_open(FileName, access_flags | O_CREAT);
 #else
-  fd= open((char *) FileName, access_flags | O_CREAT,
+  fd= open((char *) FileName, access_flags | O_CREAT | O_CLOEXEC,
 	    CreateFlags ? CreateFlags : my_umask);
 #endif
 

mysys/my_fopen.c

@@ -42,7 +42,7 @@ static void make_ftype(char * to,int flag);
 FILE *my_fopen(const char *filename, int flags, myf MyFlags)
 {
   FILE *fd;
-  char type[5];
+  char type[10];
   DBUG_ENTER("my_fopen");
   DBUG_PRINT("my",("Name: '%s'  flags: %d  MyFlags: %lu",
 		   filename, flags, MyFlags));
@@ -351,9 +351,11 @@ static void make_ftype(register char * to, register int flag)
   else    
     *to++= 'r';
 
-#if FILE_BINARY            /* If we have binary-files */  
   if (flag & FILE_BINARY)    
     *to++='b';
-#endif  
+
+  if (O_CLOEXEC)
+    *to++= 'e';
+
   *to='\0';
 } /* make_ftype */

mysys/my_open.c

@@ -46,9 +46,9 @@ File my_open(const char *FileName, int Flags, myf MyFlags)
 #if defined(_WIN32)
   fd= my_win_open(FileName, Flags);
 #elif !defined(NO_OPEN_3)
-  fd = open(FileName, Flags, my_umask);	/* Normal unix */
+  fd = open(FileName, Flags | O_CLOEXEC, my_umask);     /* Normal unix */
 #else
-  fd = open((char *) FileName, Flags);
+  fd = open((char *) FileName, Flags | O_CLOEXEC);
 #endif
 
   fd= my_register_filename(fd, FileName, FILE_BY_OPEN,