From 68cd5aff1467638c086f1bedcc750e34917168e4 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 30 Oct 2009 04:47:29 +0100
Subject: use O_CLOEXEC if available

---
 libasyncns/asyncns.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/libasyncns/asyncns.c b/libasyncns/asyncns.c
index e5d4291..bc0b708 100644
--- a/libasyncns/asyncns.c
+++ b/libasyncns/asyncns.c
@@ -83,7 +83,7 @@ enum {
 };
 
 struct asyncns {
-    int fds[4];
+    int fds[MESSAGE_FD_MAX];
 
 #ifndef HAVE_PTHREAD
     pid_t workers[MAX_WORKERS];
@@ -221,6 +221,8 @@ static int close_allv(const int except_fds[]) {
 
     assert(except_fds);
 
+    /* We ignore FD_CLOEXEC here, since this is called in the child only anyway */
+
     if ((d = opendir("/proc/self/fd"))) {
 
         struct dirent *de;
@@ -781,9 +783,21 @@ asyncns_t* asyncns_new(unsigned n_proc) {
 
     memset(asyncns->queries, 0, sizeof(asyncns->queries));
 
-    if (socketpair(PF_UNIX, SOCK_DGRAM, 0, asyncns->fds) < 0 ||
-        socketpair(PF_UNIX, SOCK_DGRAM, 0, asyncns->fds+2) < 0)
-        goto fail;
+#ifdef SOCK_CLOEXEC
+    if (socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, asyncns->fds) < 0 ||
+        socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, asyncns->fds+2) < 0) {
+
+        /* Try again, without SOCK_CLOEXEC */
+        if (errno == EINVAL) {
+#endif
+            if (socketpair(PF_UNIX, SOCK_DGRAM, 0, asyncns->fds) < 0 ||
+                socketpair(PF_UNIX, SOCK_DGRAM, 0, asyncns->fds+2) < 0)
+                goto fail;
+#ifdef SOCK_CLOEXEC
+        } else
+            goto fail;
+    }
+#endif
 
     for (i = 0; i < MESSAGE_FD_MAX; i++)
         fd_cloexec(asyncns->fds[i]);
-- 
cgit