Allow to use global LZO library instead of miniLZO

The complete LZO library nowadays is installed on many systems so we can
optionally make use of it and omit internal miniLZO implementation.

.travis.yml

@@ -22,7 +22,7 @@ before_install:
 script:
   - mkdir build
   - cd build
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get update; sudo apt-get --no-install-suggests --no-install-recommends install libsdl2-dev; fi
+  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then sudo apt-get update; sudo apt-get --no-install-suggests --no-install-recommends install libsdl2-dev liblzo2-dev; fi
   - if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then brew update; brew install sdl2; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then cmake .. -DOPENSSL_ROOT_DIR=/usr/local/opt/openssl; else cmake ..; fi
   - cmake --build .

CMakeLists.txt

@@ -35,6 +35,7 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR} ${CM
 # all the build configuration switches
 option(BUILD_SHARED_LIBS "Build shared libraries" ${UNIX})
 option(WITH_ZLIB "Search for the zlib compression library to support additional encodings" ON)
+option(WITH_LZO "Search for the LZO compression library to omit internal miniLZO implementation" ON)
 option(WITH_JPEG "Search for the libjpeg compression library to support additional encodings" ON)
 option(WITH_PNG "Search for the PNG compression library to support additional encodings" ON)
 option(WITH_SDL "Search for the Simple Direct Media Layer library to build an example SDL vnc client" ON)
@@ -56,6 +57,9 @@ if(WITH_ZLIB)
   find_package(ZLIB)
 endif(WITH_ZLIB)
 
+if(WITH_LZO)
+  find_package(LZO)
+endif()
 
 if(WITH_JPEG)
   find_package(JPEG)
@@ -189,6 +193,11 @@ if(ZLIB_FOUND)
 else()
   unset(ZLIB_LIBRARIES) # would otherwise contain -NOTFOUND, confusing target_link_libraries()
 endif(ZLIB_FOUND)
+if(LZO_FOUND)
+  set(LIBVNCSERVER_HAVE_LZO 1)
+else()
+  unset(LZO_LIBRARIES CACHE) # would otherwise contain -NOTFOUND, confusing target_link_libraries()
+endif()
 if(JPEG_FOUND)
   set(LIBVNCSERVER_HAVE_LIBJPEG 1)
 else()
@@ -317,7 +326,6 @@ set(LIBVNCSERVER_SOURCES
     ${COMMON_DIR}/d3des.c
     ${COMMON_DIR}/vncauth.c
     ${LIBVNCSERVER_DIR}/cargs.c
-    ${COMMON_DIR}/minilzo.c
     ${LIBVNCSERVER_DIR}/ultra.c
     ${LIBVNCSERVER_DIR}/scale.c
 )
@@ -328,7 +336,6 @@ set(LIBVNCCLIENT_SOURCES
     ${LIBVNCCLIENT_DIR}/rfbproto.c
     ${LIBVNCCLIENT_DIR}/sockets.c
     ${LIBVNCCLIENT_DIR}/vncviewer.c
-    ${COMMON_DIR}/minilzo.c
 )
 
 if(JPEG_FOUND)
@@ -388,6 +395,20 @@ if(ZLIB_FOUND)
   )
 endif(ZLIB_FOUND)
 
+if(LZO_FOUND)
+  add_definitions(-DLIBVNCSERVER_HAVE_LZO)
+  include_directories(${LZO_INCLUDE_DIR})
+else()
+  set(LIBVNCSERVER_SOURCES
+    ${LIBVNCSERVER_SOURCES}
+    ${COMMON_DIR}/minilzo.c
+  )
+  set(LIBVNCCLIENT_SOURCES
+    ${LIBVNCCLIENT_SOURCES}
+    ${COMMON_DIR}/minilzo.c
+  )
+endif()
+
 if(JPEG_FOUND)
   add_definitions(-DLIBVNCSERVER_HAVE_LIBJPEG)
   include_directories(${JPEG_INCLUDE_DIR})
@@ -434,6 +455,7 @@ endif(WIN32)
 target_link_libraries(vncclient
                       ${ADDITIONAL_LIBS}
                       ${ZLIB_LIBRARIES}
+                      ${LZO_LIBRARIES}
                       ${JPEG_LIBRARIES}
                       ${GNUTLS_LIBRARIES}
                       ${OPENSSL_LIBRARIES}
@@ -441,6 +463,7 @@ target_link_libraries(vncclient
 target_link_libraries(vncserver
                       ${ADDITIONAL_LIBS}
                       ${ZLIB_LIBRARIES}
+                      ${LZO_LIBRARIES}
                       ${JPEG_LIBRARIES}
 		      ${PNG_LIBRARIES}
 		      ${CRYPTO_LIBRARIES}

cmake/Modules/FindLZO.cmake

@@ -0,0 +1,31 @@
+# Find liblzo2
+# LZO_FOUND - system has the LZO library
+# LZO_INCLUDE_DIR - the LZO include directory
+# LZO_LIBRARIES - The libraries needed to use LZO
+
+if (LZO_INCLUDE_DIR AND LZO_LIBRARIES)
+	# in cache already
+	SET(LZO_FOUND TRUE)
+else (LZO_INCLUDE_DIR AND LZO_LIBRARIES)
+	FIND_PATH(LZO_INCLUDE_DIR NAMES lzo/lzo1x.h)
+
+	FIND_LIBRARY(LZO_LIBRARIES NAMES lzo2)
+
+	if (LZO_INCLUDE_DIR AND LZO_LIBRARIES)
+		 set(LZO_FOUND TRUE)
+	endif (LZO_INCLUDE_DIR AND LZO_LIBRARIES)
+
+	if (LZO_FOUND)
+		 if (NOT LZO_FIND_QUIETLY)
+				message(STATUS "Found LZO: ${LZO_LIBRARIES}")
+		 endif (NOT LZO_FIND_QUIETLY)
+	else (LZO_FOUND)
+		 if (LZO_FIND_REQUIRED)
+				message(FATAL_ERROR "Could NOT find LZO")
+         else()
+				message(STATUS "Could NOT find LZO")
+		 endif (LZO_FIND_REQUIRED)
+	endif (LZO_FOUND)
+
+#	MARK_AS_ADVANCED(LZO_INCLUDE_DIR LZO_LIBRARIES)
+endif (LZO_INCLUDE_DIR AND LZO_LIBRARIES)

libvncclient/rfbproto.c

@@ -61,7 +61,11 @@
 #endif
 
 #include "sasl.h"
+#ifdef LIBVNCSERVER_HAVE_LZO
+#include <lzo/lzo1x.h>
+#else
 #include "minilzo.h"
+#endif
 #include "tls.h"
 
 #ifdef _MSC_VER

libvncserver/ultra.c

@@ -8,7 +8,11 @@
  */
 
 #include <rfb/rfb.h>
+#ifdef LIBVNCSERVER_HAVE_LZO
+#include <lzo/lzo1x.h>
+#else
 #include "minilzo.h"
+#endif
 
 /*
  * cl->beforeEncBuf contains pixel data in the client's format.

rfb/rfbconfig.h.cmakein

@@ -72,6 +72,9 @@
 /* Define to 1 if you have the `z' library (-lz). */
 #cmakedefine LIBVNCSERVER_HAVE_LIBZ  1 
 
+/* Define to 1 if you have the `lzo2' library (-llzo2). */
+#cmakedefine LIBVNCSERVER_HAVE_LZO  1
+
 /* Define to 1 if you have the <netinet/in.h> header file. */
 #cmakedefine LIBVNCSERVER_HAVE_NETINET_IN_H  1