Add --disable-zlib configure option

m4/zlib.m4

@@ -2,32 +2,37 @@ dnl Check to find the zlib headers/libraries
 
 AC_DEFUN([tinc_ZLIB],
 [
-  AC_ARG_WITH(zlib,
-    AS_HELP_STRING([--with-zlib=DIR], [zlib base directory, or:]),
-    [zlib="$withval"
-     CPPFLAGS="$CPPFLAGS -I$withval/include"
-     LDFLAGS="$LDFLAGS -L$withval/lib"]
-  )
+  AC_ARG_ENABLE([zlib],
+    AS_HELP_STRING([--disable-zlib], [disable zlib compression support]))
+  AS_IF([test "x$enable_zlib" != "xno"], [
+  AC_DEFINE(HAVE_ZLIB, 1, [have zlib compression support])
+    AC_ARG_WITH(zlib,
+      AS_HELP_STRING([--with-zlib=DIR], [zlib base directory, or:]),
+      [zlib="$withval"
+       CPPFLAGS="$CPPFLAGS -I$withval/include"
+       LDFLAGS="$LDFLAGS -L$withval/lib"]
+    )
 
-  AC_ARG_WITH(zlib-include,
-    AS_HELP_STRING([--with-zlib-include=DIR], [zlib headers directory]),
-    [zlib_include="$withval"
-     CPPFLAGS="$CPPFLAGS -I$withval"]
-  )
+    AC_ARG_WITH(zlib-include,
+      AS_HELP_STRING([--with-zlib-include=DIR], [zlib headers directory]),
+      [zlib_include="$withval"
+       CPPFLAGS="$CPPFLAGS -I$withval"]
+    )
 
-  AC_ARG_WITH(zlib-lib,
-    AS_HELP_STRING([--with-zlib-lib=DIR], [zlib library directory]),
-    [zlib_lib="$withval"
-     LDFLAGS="$LDFLAGS -L$withval"]
-  )
+    AC_ARG_WITH(zlib-lib,
+      AS_HELP_STRING([--with-zlib-lib=DIR], [zlib library directory]),
+      [zlib_lib="$withval"
+       LDFLAGS="$LDFLAGS -L$withval"]
+    )
 
-  AC_CHECK_HEADERS(zlib.h,
-    [],
-    [AC_MSG_ERROR("zlib header files not found."); break]
-  )
+    AC_CHECK_HEADERS(zlib.h,
+      [],
+      [AC_MSG_ERROR("zlib header files not found."); break]
+    )
 
-  AC_CHECK_LIB(z, compress2,
-    [LIBS="$LIBS -lz"],
-    [AC_MSG_ERROR("zlib libraries not found.")]
-  )
+    AC_CHECK_LIB(z, compress2,
+      [LIBS="$LIBS -lz"],
+      [AC_MSG_ERROR("zlib libraries not found.")]
+    )
+  ])
 ])

src/net_packet.c

@@ -26,7 +26,9 @@
 #include <openssl/pem.h>
 #include <openssl/hmac.h>
 
+#ifdef HAVE_ZLIB
 #include <zlib.h>
+#endif
 
 #ifdef HAVE_LZO
 #include LZO1X_H
@@ -152,7 +154,10 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) {
 }
 
 static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-	if(level == 10) {
+	if(level == 0) {
+		memcpy(dest, source, len);
+		return len;
+	} else if(level == 10) {
 #ifdef HAVE_LZO
 		lzo_uint lzolen = MAXSIZE;
 		lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem);
@@ -161,10 +166,12 @@ static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t l
 		return -1;
 #endif
 	} else if(level < 10) {
+#ifdef HAVE_ZLIB
 		unsigned long destlen = MAXSIZE;
 		if(compress2(dest, &destlen, source, len, level) == Z_OK)
 			return destlen;
 		else
+#endif
 			return -1;
 	} else {
 #ifdef HAVE_LZO
@@ -180,7 +187,10 @@ static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t l
 }
 
 static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) {
-	if(level > 9) {
+	if(level == 0) {
+		memcpy(dest, source, len);
+		return len;
+	} else if(level > 9) {
 #ifdef HAVE_LZO
 		lzo_uint lzolen = MAXSIZE;
 		if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK)
@@ -188,14 +198,17 @@ static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t
 		else
 #endif
 			return -1;
-	} else {
+	}
+#ifdef HAVE_ZLIB
+	else {
 		unsigned long destlen = MAXSIZE;
 		if(uncompress(dest, &destlen, source, len) == Z_OK)
 			return destlen;
 		else
 			return -1;
 	}
-	
+#endif
+
 	return -1;
 }