build,examples: use libsshtunnel for ssh tunnel example

...instead of libssh2 directly and lots of application logic.

CMakeLists.txt

@@ -51,7 +51,7 @@ option(WITH_JPEG "Search for the libjpeg compression library to support addition
 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)
 option(WITH_GTK "Search for the GTK library to build an example GTK vnc client" ON)
-option(WITH_LIBSSH2 "Search for libssh2 to build an example ssh-tunneled client" ON)
+option(WITH_LIBSSHTUNNEL "Search for libsshtunnel to build an example ssh-tunneled client" ON)
 option(WITH_THREADS "Search for a threading library to build with multithreading support" ON)
 option(PREFER_WIN32THREADS "When searching for a threading library, prefer win32 threads if they are found" OFF)
 option(WITH_GNUTLS "Search for the GnuTLS secure communications library to support TLS" ON)
@@ -145,9 +145,14 @@ if(WITH_GTK)
   find_package(GTK2)
 endif(WITH_GTK)
 
-if(WITH_LIBSSH2)
-  find_package(LibSSH2)
-endif(WITH_LIBSSH2)
+if(WITH_LIBSSHTUNNEL)
+  find_path(LIBSSHTUNNEL_INCLUDE_DIR libsshtunnel.h)
+  find_library(LIBSSHTUNNEL_LIBRARY sshtunnel)
+  if("${LIBSSHTUNNEL_LIBRARY}" MATCHES ".*NOTFOUND.*")
+    # would otherwise contain -NOTFOUND, confusing target_link_libraries()
+    set(LIBSSHTUNNEL_LIBRARY "")
+  endif()
+endif(WITH_LIBSSHTUNNEL)
 
 if(WITH_THREADS)
   find_package(Threads)
@@ -628,17 +633,14 @@ if(GTK2_FOUND)
   )
 endif(GTK2_FOUND)
 
-if(LIBSSH2_FOUND AND (CMAKE_USE_PTHREADS_INIT OR CMAKE_USE_WIN32_THREADS_INIT))
-  include_directories(${LIBSSH2_INCLUDE_DIR})
+if(WITH_LIBSSHTUNNEL AND LIBSSHTUNNEL_LIBRARY AND LIBSSHTUNNEL_INCLUDE_DIR)
+  message(STATUS "Building with libsshtunnel: ${LIBSSHTUNNEL_LIBRARY} and ${LIBSSHTUNNEL_INCLUDE_DIR}")
+  include_directories(${LIBSSHTUNNEL_INCLUDE_DIR})
   set(LIBVNCCLIENT_EXAMPLES
     ${LIBVNCCLIENT_EXAMPLES}
     sshtunnel
   )
 endif()
-# if not found, set lib var to empty, otherwise CMake complains
-if(NOT LIBSSH2_FOUND)
-  set(LIBSSH2_LIBRARY "")
-endif()
 
 if(FFMPEG_FOUND)
   include_directories(${FFMPEG_INCLUDE_DIRS})
@@ -660,7 +662,7 @@ if(WITH_EXAMPLES)
     add_executable(client_examples_${e} ${LIBVNCCLIEXAMPLE_DIR}/${e}.c ${LIBVNCCLIEXAMPLE_DIR}/${${e}_EXTRA_SOURCES} )
     set_target_properties(client_examples_${e} PROPERTIES OUTPUT_NAME ${e})
     set_target_properties(client_examples_${e} PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/examples/client)
-    target_link_libraries(client_examples_${e} vncclient ${CMAKE_THREAD_LIBS_INIT} ${SDL2_LIBRARY} ${GTK2_LIBRARIES} ${FFMPEG_LIBRARIES} ${LIBSSH2_LIBRARY})
+    target_link_libraries(client_examples_${e} vncclient ${CMAKE_THREAD_LIBS_INIT} ${SDL2_LIBRARY} ${GTK2_LIBRARIES} ${FFMPEG_LIBRARIES} ${LIBSSHTUNNEL_LIBRARY})
   endforeach(e ${LIBVNCCLIENT_EXAMPLES})
 endif(WITH_EXAMPLES)