use a configure script test for PMTU discovery control instead of just assuming it's available on Linux

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@45027 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 43997 .
+# From configure.ac Revision: 44055 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.60a.
 #
@@ -14345,6 +14345,76 @@ echo "${ECHO_T}no" >&6; }
 
 fi
 
+rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
+      conftest$ac_exeext conftest.$ac_ext
+
+{ echo "$as_me:$LINENO: checking for IP_MTU_DISCOVER" >&5
+echo $ECHO_N "checking for IP_MTU_DISCOVER... $ECHO_C" >&6; }
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+#include <netinet/in.h>
+int
+main ()
+{
+int foo = IP_MTU_DISCOVER;
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  { echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_IP_MTU_DISCOVER 1
+_ACEOF
+
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	{ echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+
+fi
+
 rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
       conftest$ac_exeext conftest.$ac_ext
 

configure.ac

@@ -296,6 +296,15 @@ AC_LINK_IFELSE(
 	AC_MSG_RESULT(no)
 )
 
+AC_MSG_CHECKING(for IP_MTU_DISCOVER)
+AC_LINK_IFELSE(
+	AC_LANG_PROGRAM([#include <netinet/in.h>],
+			[int foo = IP_MTU_DISCOVER;]),
+	AC_MSG_RESULT(yes)
+	AC_DEFINE([HAVE_IP_MTU_DISCOVER], 1, [Define to 1 if your system has PMTU discovery on UDP sockets.]),
+	AC_MSG_RESULT(no)
+)
+
 AC_CHECK_HEADER([libkern/OSAtomic.h],
                 [AC_DEFINE_UNQUOTED([HAVE_OSX_ATOMICS], 1, [Define to 1 if OSX atomic operations are supported.])])
 

include/asterisk/autoconfig.h.in

@@ -148,6 +148,9 @@
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
+/* Define to 1 if your system has PMTU discovery on UDP sockets. */
+#undef HAVE_IP_MTU_DISCOVER
+
 /* Define to 1 if you have the `isascii' function. */
 #undef HAVE_ISASCII
 

main/utils.c

@@ -987,10 +987,10 @@ int ast_dynamic_str_thread_build_va(struct ast_dynamic_str **buf, size_t max_len
 
 void ast_enable_packet_fragmentation(int sock)
 {
-#ifdef __linux__
+#if defined(HAVE_IP_MTU_DISCOVER)
 	int val = IP_PMTUDISC_DONT;
 	
 	if (setsockopt(sock, IPPROTO_IP, IP_MTU_DISCOVER, &val, sizeof(val)))
 		ast_log(LOG_WARNING, "Unable to disable PMTU discovery. Large UDP packets may fail to be delivered when sent from this socket.\n");
-#endif
+#endif /* HAVE_IP_MTU_DISCOVER */
 }