ZOOKEEPER-2338: set SOCK_CLOEXEC on socket if defined

Author: Radu Brumariu <radu@groupon.com>

Reviewers: phunt@apache.org

Closes #410 from fr0stbyte/ZOOKEEPER-2338

Change-Id: I7b060a2dc473b34aecc0cfac71d39720369bd635
(cherry picked from commit 508293d6a139eeb59d9dde5b4f72b7043f85350a)
Signed-off-by: Patrick Hunt <phunt@apache.org>

src/c/CMakeLists.txt

@@ -59,6 +59,15 @@ else()
 endif()
 option(WANT_CPPUNIT "Enables CppUnit and tests" ${DEFAULT_WANT_CPPUNIT})
 
+# SOCK_CLOEXEC
+option(WANT_SOCK_CLOEXEC "Enables SOCK_CLOEXEC on sockets" OFF)
+include(CheckSymbolExists)
+check_symbol_exists(SOCK_CLOEXEC sys/socket.h HAVE_SOCK_CLOEXEC)
+if(WANT_SOCK_CLOEXEC AND HAVE_SOCK_CLOEXEC)
+  set(SOCK_CLOEXEC_ENABLED 1)
+endif()
+
+
 # The function `to_have(in out)` converts a header name like `arpa/inet.h`
 # into an Autotools style preprocessor definition `HAVE_ARPA_INET_H`.
 # This is then set or unset in `configure_file()` step.

src/c/cmake_config.h.in

@@ -127,6 +127,9 @@
 /* Define to 1 if IPv6 support is available. */
 #cmakedefine ZOO_IPV6_ENABLED 1
 
+/* Define to 1 if SOCK_CLOEXEC is available and wanted */
+#cmakedefine SOCK_CLOEXEC_ENABLED 1
+
 /* poll() second argument type */
 #define POLL_NFDS_TYPE nfds_t
 

src/c/configure.ac

@@ -130,11 +130,11 @@ main()
  else
    exit(0);
 }
-], AC_MSG_RESULT(yes) 
-   ipv6=yes, 
-   AC_MSG_RESULT(no) 
-   ipv6=no, 
-   AC_MSG_RESULT(no) 
+], AC_MSG_RESULT(yes)
+   ipv6=yes,
+   AC_MSG_RESULT(no)
+   ipv6=no,
+   AC_MSG_RESULT(no)
    ipv6=no)
 
 if test x"$ipv6" = xyes; then
@@ -142,6 +142,46 @@ if test x"$ipv6" = xyes; then
   AC_SUBST(USEIPV6)
 fi
 
+# use SOCK_CLOEXEC if available and wanted
+AC_ARG_WITH([sock_cloexec],
+[AS_HELP_STRING([--with-sock-cloexec],[build with SOCK_CLOEXEC flag set on the connections])],
+[],[with_sock_cloexec=no])
+
+AC_MSG_CHECKING([whether SOCK_CLOEXEC is available])
+
+AC_TRY_RUN([ /* is SOCK_CLOEXEC available ? */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdlib.h>
+main()
+{
+#ifdef SOCK_CLOEXEC
+  exit(0);
+#else
+  exit(1);
+#endif
+}
+], AC_MSG_RESULT(yes)
+   has_sock_cloexec=yes,
+   AC_MSG_RESULT(no)
+   has_sock_cloexec=no,
+   AC_MSG_RESULT(no)
+   has_sock_cloexec=no)
+
+if test "x$with_sock_cloexec" != xno && test "x$has_sock_cloexec" = xno; then
+  AC_MSG_WARN([cannot use SOCK_CLOEXEC -- SOCK_CLOEXEC undefined on this platform])
+  with_sock_cloexec=no
+fi
+
+if test "x$with_sock_cloexec" != xno; then
+AC_MSG_NOTICE([building with SOCK_CLOEXEC])
+else
+AC_MSG_NOTICE([building without SOCK_CLOEXEC])
+fi
+
+AS_IF([test x"$with_sock_cloexec" != xno], [AC_DEFINE([SOCK_CLOEXEC_ENABLED], [1], [Define to 1, if SOCK_CLOEXEC is defined and wanted])])
+AM_CONDITIONAL([SOCK_CLOEXEC_ENABLED],[test "x$with_sock_cloexec" != xno])
+
 # Determine which libraries we need to use clock_gettime
 saved_LIBS="$LIBS"
 LIBS=""

src/c/src/zookeeper.c

@@ -1700,7 +1700,7 @@ void free_completions(zhandle_t *zh,int callCompletion,int reason)
 
         get_auth_completions(&zh->auth_h, &a_list);
         zoo_unlock_auth(zh);
-    
+
         a_tmp = &a_list;
         // chain call user's completion function
         while (a_tmp->completion != NULL) {
@@ -2087,10 +2087,16 @@ static int ping_rw_server(zhandle_t* zh)
     socket_t sock;
     int rc;
     sendsize_t ssize;
+    int sock_flags;
 
     addrvec_peek(&zh->addrs, &zh->addr_rw_server);
 
-    sock = socket(zh->addr_rw_server.ss_family, SOCK_STREAM, 0);
+#ifdef SOCK_CLOEXEC_ENABLED
+    sock_flags = SOCK_STREAM | SOCK_CLOEXEC;
+#else
+    sock_flags = SOCK_STREAM;
+#endif
+    sock = socket(zh->addr_rw_server.ss_family, sock_flags, 0);
     if (sock < 0) {
         return 0;
     }
@@ -2221,8 +2227,16 @@ static socket_t zookeeper_connect(zhandle_t *zh,
 int zookeeper_interest(zhandle_t *zh, socket_t *fd, int *interest,
      struct timeval *tv)
 {
+    int sock_flags;
     int rc = 0;
     struct timeval now;
+
+#ifdef SOCK_CLOEXEC_ENABLED
+    sock_flags = SOCK_STREAM | SOCK_CLOEXEC;
+#else
+    sock_flags = SOCK_STREAM;
+#endif
+
     if(zh==0 || fd==0 ||interest==0 || tv==0)
         return ZBADARGUMENTS;
     if (is_unrecoverable(zh))
@@ -2272,7 +2286,7 @@ int zookeeper_interest(zhandle_t *zh, socket_t *fd, int *interest,
                 // No need to delay -- grab the next server and attempt connection
                 zoo_cycle_next_server(zh);
             }
-            zh->fd = socket(zh->addr_cur.ss_family, SOCK_STREAM, 0);
+            zh->fd = socket(zh->addr_cur.ss_family, sock_flags, 0);
             if (zh->fd < 0) {
               rc = handle_socket_error_msg(zh,
                                            __LINE__,
@@ -2607,7 +2621,7 @@ static int deserialize_multi(zhandle_t *zh, int xid, completion_list_t *cptr, st
 
         deserialize_response(zh, entry->c.type, xid, mhdr.type == -1, mhdr.err, entry, ia);
         deserialize_MultiHeader(ia, "multiheader", &mhdr);
-        //While deserializing the response we must destroy completion entry for each operation in 
+        //While deserializing the response we must destroy completion entry for each operation in
         //the zoo_multi transaction. Otherwise this results in memory leak when client invokes zoo_multi
         //operation.
         destroy_completion_entry(entry);
@@ -3524,7 +3538,7 @@ int zoo_acreate(zhandle_t *zh, const char *path, const char *value,
     struct RequestHeader h = {get_xid(), ZOO_CREATE_OP};
     struct CreateRequest req;
 
-    int rc = CreateRequest_init(zh, &req, 
+    int rc = CreateRequest_init(zh, &req,
             path, value, valuelen, acl_entries, flags);
     if (rc != ZOK) {
         return rc;
@@ -3632,7 +3646,7 @@ int zoo_awexists(zhandle_t *zh, const char *path,
     struct oarchive *oa;
     struct RequestHeader h = {get_xid(), ZOO_EXISTS_OP};
     struct ExistsRequest req;
-    int rc = Request_path_watch_init(zh, 0, &req.path, path, 
+    int rc = Request_path_watch_init(zh, 0, &req.path, path,
             &req.watch, watcher != NULL);
     if (rc != ZOK) {
         return rc;
@@ -3666,7 +3680,7 @@ static int zoo_awget_children_(zhandle_t *zh, const char *path,
     struct oarchive *oa;
     struct RequestHeader h = {get_xid(), ZOO_GETCHILDREN_OP};
     struct GetChildrenRequest req ;
-    int rc = Request_path_watch_init(zh, 0, &req.path, path, 
+    int rc = Request_path_watch_init(zh, 0, &req.path, path,
             &req.watch, watcher != NULL);
     if (rc != ZOK) {
         return rc;
@@ -3714,7 +3728,7 @@ static int zoo_awget_children2_(zhandle_t *zh, const char *path,
     struct oarchive *oa;
     struct RequestHeader h = {get_xid(), ZOO_GETCHILDREN2_OP};
     struct GetChildren2Request req ;
-    int rc = Request_path_watch_init(zh, 0, &req.path, path, 
+    int rc = Request_path_watch_init(zh, 0, &req.path, path,
             &req.watch, watcher != NULL);
     if (rc != ZOK) {
         return rc;
@@ -4090,7 +4104,7 @@ void zoo_create_op_init(zoo_op_t *op, const char *path, const char *value,
 }
 
 void zoo_create2_op_init(zoo_op_t *op, const char *path, const char *value,
-        int valuelen,  const struct ACL_vector *acl, int flags, 
+        int valuelen,  const struct ACL_vector *acl, int flags,
         char *path_buffer, int path_buffer_len)
 {
     assert(op);