1 files changed, 65 insertions, 0 deletions
diff --git a/libc/inet/check_pf.c b/libc/inet/check_pf.c
new file mode 100644
index 000000000..b6c93783a
--- /dev/null
+++ b/libc/inet/check_pf.c
@@ -0,0 +1,65 @@
+/* Determine protocol families for which interfaces exist.  Generic version.
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <features.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+
+
+void
+attribute_hidden
+__check_pf (bool *seen_ipv4, bool *seen_ipv6)
+{
+  *seen_ipv4 = false;
+  *seen_ipv6 = false;
+#if __UCLIBC_SUPPORT_AI_ADDRCONFIG__
+  {
+    /* Get the interface list via getifaddrs.  */
+    struct ifaddrs *ifa = NULL;
+    struct ifaddrs *runp;
+    if (getifaddrs (&ifa) != 0)
+    {
+      /* We cannot determine what interfaces are available.  Be
+      optimistic.  */
+      *seen_ipv4 = true;
+#if __UCLIBC_HAS_IPV6__
+      *seen_ipv6 = true;
+#endif /* __UCLIBC_HAS_IPV6__ */
+      return;
+    }
+
+    for (runp = ifa; runp != NULL; runp = runp->ifa_next)
+      if (runp->ifa_addr->sa_family == PF_INET)
+        *seen_ipv4 = true;
+#if __UCLIBC_HAS_IPV6__
+      else if (runp->ifa_addr->sa_family == PF_INET6)
+        *seen_ipv6 = true;
+#endif /* __UCLIBC_HAS_IPV6__ */
+
+    (void) freeifaddrs (ifa);
+  }
+#else
+  /* AI_ADDRCONFIG is disabled, assume both ipv4 and ipv6 available. */
+  *seen_ipv4 = true;
+#if __UCLIBC_HAS_IPV6__
+  *seen_ipv6 = true;
+#endif /* __UCLIBC_HAS_IPV6__ */
+
+#endif /* __UCLIBC_SUPPORT_AI_ADDRCONFIG__ */
+}