From 48032aed00246327132bc4262b8d9e22680778ba Mon Sep 17 00:00:00 2001
From: Andreas Steffen <andreas.steffen@strongswan.org>
Date: Fri, 9 Jan 2009 01:19:45 +0000
Subject: [PATCH] add a compatible memrchr() function if the platform does not
 support it (e.g. old glibc). Patch courtesy to Thomas Jarosch

---
 configure.in                        |  1 +
 src/libstrongswan/Makefile.am       |  1 +
 src/libstrongswan/utils/lexparser.c |  3 ++
 src/libstrongswan/utils/memrchr.c   | 45 +++++++++++++++++++++++++++++
 4 files changed, 50 insertions(+)
 create mode 100644 src/libstrongswan/utils/memrchr.c

diff --git a/configure.in b/configure.in
index ff1c25ee8..45dc82936 100644
--- a/configure.in
+++ b/configure.in
@@ -707,6 +707,7 @@ dnl ==========================================
 AC_HAVE_LIBRARY(dl)
 AC_CHECK_FUNCS(backtrace)
 AC_CHECK_FUNCS(dladdr)
+AC_REPLACE_FUNCS(memrchr)
 
 AC_MSG_CHECKING([for gcc atomic operations])
 AC_TRY_RUN(
diff --git a/src/libstrongswan/Makefile.am b/src/libstrongswan/Makefile.am
index 1463d415f..aa0e1d83e 100644
--- a/src/libstrongswan/Makefile.am
+++ b/src/libstrongswan/Makefile.am
@@ -47,6 +47,7 @@ utils/identification.c utils/identification.h \
 utils/iterator.h \
 utils/lexparser.c utils/lexparser.h \
 utils/linked_list.c utils/linked_list.h \
+utils/memrchr.c \
 utils/hashtable.c utils/hashtable.h \
 utils/enumerator.c utils/enumerator.h \
 utils/optionsfrom.c utils/optionsfrom.h \
diff --git a/src/libstrongswan/utils/lexparser.c b/src/libstrongswan/utils/lexparser.c
index 34eb340a5..c351e7e24 100644
--- a/src/libstrongswan/utils/lexparser.c
+++ b/src/libstrongswan/utils/lexparser.c
@@ -20,6 +20,9 @@
 
 #include "lexparser.h"
 
+#ifndef HAVE_MEMRCHR
+void *memrchr(const void *s, int c, size_t n);
+#endif
 
 /**
  * eat whitespace
diff --git a/src/libstrongswan/utils/memrchr.c b/src/libstrongswan/utils/memrchr.c
new file mode 100644
index 000000000..efcd03aa0
--- /dev/null
+++ b/src/libstrongswan/utils/memrchr.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2008 Thomas Jarosch
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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 General Public License
+ * for more details.
+ */
+
+#ifndef HAVE_MEMRCHR
+
+#include <string.h>
+
+void *memrchr(const void *s, int c, size_t n)
+{
+	unsigned char *reverse_search;
+
+	if (s == NULL || n == 0)
+	{
+		return NULL;
+	}
+
+	reverse_search = s + n;
+
+	for (;;)
+	{
+		if (*reverse_search == (unsigned char)c)
+		{
+			return reverse_search;
+		}
+		else if (reverse_search == s)
+		{
+			break;
+		}
+		reverse_search--;
+	}
+	return NULL;
+}
+
+#endif