Add Windows support

Author: JKRhb

.github/workflows/main.yml

@@ -62,3 +62,15 @@ jobs:
       run: |
         cmake -Dmake_tests=ON .
         make
+
+  build-windows:
+    name: Build for Windows using CMake
+    runs-on: windows-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Build tinydtls
+      run: |
+        cmake -G "Unix Makefiles" .
+        make
+

.gitignore

@@ -51,6 +51,7 @@ dtls_config.h
 *.cooja
 *.econotag
 *.eval-adf7xxxmb4z
+*.exe
 *.exp5438
 *.iris
 *.mbxxx
@@ -70,3 +71,23 @@ dtls_config.h
 CMakeCache.txt
 cmake_install.cmake
 CMakeFiles
+
+# Windows build files
+*.dll
+
+# Visual Studio Build Files
+*.VC.db*
+.vs
+*.obj
+*.tlog
+*.log
+*.recipe
+*.vcxproj
+*.sln
+*.pdb
+*.vcxproj.user
+*.vcxproj.filters
+*.vcxproj.FileListAbsolute.txt
+tinydtls.dir
+Debug
+Release

CMakeLists.txt

@@ -31,7 +31,7 @@ option(make_tests "Make test programs and examples" OFF)
 if(NOT PLATFORM)
    # PLATFORM seems to be not used
    set(PLATFORM "posix" CACHE STRING "Choose platform." FORCE)
-   set_property(CACHE PLATFORM PROPERTY STRINGS "contiki" "espidf" "posix" "riot" "zephyr")
+   set_property(CACHE PLATFORM PROPERTY STRINGS "contiki" "espidf" "posix" "riot" "zephyr" "windows")
 endif()
 
 set(PACKAGE_NAME "tinydtls")
@@ -64,8 +64,11 @@ target_sources(tinydtls PRIVATE
 target_include_directories(tinydtls PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR})
 target_compile_definitions(tinydtls PUBLIC DTLSv12 WITH_SHA256 SHA2_USE_INTTYPES_H DTLS_CHECK_CONTENTTYPE)
 
-if(NOT ZEPHYR_BASE)
-   target_compile_options(tinydtls PRIVATE -fPIC -pedantic -std=c99 -Wall -Wextra -Wformat-security -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wunused)
+if(CMAKE_GENERATOR MATCHES "Visual Studio")
+    option(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS "Export all symbols when compiling to a .dll" ON)
+    target_compile_options(tinydtls PRIVATE -Wall)
+elseif(NOT ZEPHYR_BASE)
+    target_compile_options(tinydtls PRIVATE -fPIC -pedantic -std=c99 -Wall -Wextra -Wformat-security -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wunused)
 endif()
 
 set_target_properties(tinydtls PROPERTIES VERSION ${PACKAGE_VERSION} SOVERSION ${SOVERSION})

README.md

@@ -18,6 +18,12 @@ C99. The following components are available:
 
 # BUILDING
 
+tinydtls supports multiple platforms, including both Real-time
+and general-purpose Operating Systems. Below you find build instructions for
+all supported environments.
+
+## POSIX-oriented Operating Systems
+
 When using the code from the git
 [repository](https://github.com/eclipse/tinydtls) at GitHub, invoke
 
@@ -68,6 +74,39 @@ Available options:
 | DTLS_ECC | enable/disable ECDHE_ECDSA cipher suites | ON |
 | DTLS_PSK | enable/disable PSK cipher suites | ON |
 
+## Windows
+
+Using CMake, you can also build on and for Windows using either GCC or Visual
+Studio.
+Note, however, that the `make_tests` option is currently not supported when
+compiling with Visual Studio, as parts of the tests rely on POSIX APIs.
+
+For Visual Studio, you can apply the CMake instructions outlined above from the
+command line or use the CMake GUI application.
+
+In order to be able to use GCC, you need to specify a different generator than
+the default.
+For instance, you can use the `Unix Makefiles` generator, which creates a
+Makefile for controlling the build process using GCC.
+The example below leads to the output of a shared library file
+`libtinydtls.dll`.
+
+```
+cmake -G "Unix Makefiles" -DBUILD_SHARED_LIBS=ON .
+make
+```
+
+Using MinGW64, you can also cross compile from a POSIX-oriented
+platform for Windows using Autotools by providing a corresponding `--host`
+argument:
+
+```
+./autogen.sh
+./configure --host x86_64-w64-mingw32
+make
+mv libtinydtls.so libtinydtls.dll # Apply Windows file extension
+```
+
 # License
 
 Copyright (c) 2011–2022 Olaf Bergmann (TZI) and others.

dtls.c

@@ -213,7 +213,7 @@ static inline void free_context(dtls_context_t *context) {
 }
 #endif /* RIOT_VERSION */
 
-#ifdef WITH_POSIX
+#if defined(WITH_POSIX) || defined(IS_WINDOWS)
 
 static inline dtls_context_t *
 malloc_context(void) {
@@ -1610,9 +1610,11 @@ dtls_0_send_hello_verify_request(dtls_context_t *ctx,
 			     dtls_ephemeral_peer_t *ephemeral_peer,
 			     uint8 *data, size_t data_length)
 {
-  uint8 buf[DTLS_RH_LENGTH + DTLS_HS_LENGTH + data_length];
+  uint8 buf[DTLS_RH_LENGTH + DTLS_HS_LENGTH + DTLS_HV_LENGTH + DTLS_COOKIE_LENGTH];
   uint8 *p = dtls_set_record_header(DTLS_CT_HANDSHAKE, 0, &(ephemeral_peer->rseq), buf);
 
+  assert(data_length == DTLS_HV_LENGTH + DTLS_COOKIE_LENGTH);
+
   /* Signal DTLS version 1.0 in the record layer of ClientHello and
    * HelloVerifyRequest handshake messages according to Section 4.2.1
    * of RFC 6347.

dtls.h

@@ -341,8 +341,16 @@ void dtls_check_retransmit(dtls_context_t *context, clock_time_t *next);
 #define DTLS_CT_HANDSHAKE          22
 #define DTLS_CT_APPLICATION_DATA   23
 
+#ifdef __GNUC__
+#define PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__))
+#elif defined(_MSC_VER)
+#define PACK( __Declaration__ ) __pragma( pack(push, 1) ) __Declaration__ __pragma( pack(pop))
+#else
+#error "Structure packing is not available for the used compiler."
+#endif
+
 /** Generic header structure of the DTLS record layer. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint8 content_type;		/**< content type of the included message */
   uint16 version;		/**< Protocol version */
   uint16 epoch;		        /**< counter for cipher state changes */
@@ -371,7 +379,7 @@ typedef struct __attribute__((__packed__)) {
 #define DTLS_HT_NO_OPTIONAL_MESSAGE        -1
 
 /** Header structure for the DTLS handshake protocol. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint8 msg_type; /**< Type of handshake message  (one of DTLS_HT_) */
   uint24 length;  /**< length of this message */
   uint16 message_seq; 	/**< Message sequence number */
@@ -381,7 +389,7 @@ typedef struct __attribute__((__packed__)) {
 } dtls_handshake_header_t;
 
 /** Structure of the Client Hello message. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint16 version;	  /**< Client version */
   uint32 gmt_random;	  /**< GMT time of the random byte creation */
   unsigned char random[28];	/**< Client random bytes */
@@ -392,7 +400,7 @@ typedef struct __attribute__((__packed__)) {
 } dtls_client_hello_t;
 
 /** Structure of the Hello Verify Request. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint16 version;		/**< Server version */
   uint8 cookie_length;	/**< Length of the included cookie */
   uint8 cookie[];		/**< up to 32 bytes making up the cookie */

dtls_debug.c

@@ -222,12 +222,13 @@ dsrv_print_addr(const session_t *addr, char *buf, size_t len) {
 
 #endif /* WITH_CONTIKI */
 
-#ifdef RIOT_VERSION
+#if defined(RIOT_VERSION) || defined(IS_WINDOWS)
   /* FIXME: Switch to RIOT own DEBUG lines */
+  /* TODO: Check if inet_ntop can be used on Windows */
   (void) addr;
   (void) buf;
   (void) len;
-#endif /* RIOT_VERSION */
+#endif /* RIOT_VERSION || IS_WINDOWS */
 
 #ifdef WITH_POSIX
   /* TODO: output addresses manually */
@@ -240,7 +241,7 @@ dsrv_print_addr(const session_t *addr, char *buf, size_t len) {
 
 #endif /* NDEBUG */
 
-#ifndef WITH_CONTIKI
+#if !defined(WITH_CONTIKI) && !defined(_MSC_VER)
 void
 dsrv_log(log_t level, const char *format, ...) {
   static char timebuf[32];

dtls_debug.h

@@ -78,11 +78,11 @@ void dtls_set_log_level(log_t level);
  * level is below or equal to the log level that set by
  * set_log_level(). */
 #ifdef HAVE_VPRINTF
-#if (defined(__GNUC__))
+#if (defined(__GNUC__) && !defined(__MINGW32__))
 void dsrv_log(log_t level, const char *format, ...) __attribute__ ((format(printf, 2, 3)));
-#else /* !__GNUC__ */
+#else /* !__GNUC__ && !__MINGW32__ */
 void dsrv_log(log_t level, const char *format, ...);
-#endif /* !__GNUC__ */
+#endif /* !__GNUC__ && !__MINGW32__ */
 #else
 #define dsrv_log(level, format, ...) PRINTF(format, ##__VA_ARGS__)
 #endif

dtls_mutex.h

@@ -42,18 +42,20 @@ typedef int dtls_mutex_t;
 #define dtls_mutex_trylock(a) *(a) = 1
 #define dtls_mutex_unlock(a) *(a) = 0
 
-#elif defined(WITH_ZEPHYR)
+#elif defined(WITH_ZEPHYR) || defined(IS_WINDOWS)
 
 /* zephyr supports mutex, but this port doesn't use it */
 
+// TODO: Add Windows compatible mutex definitions
+
 typedef int dtls_mutex_t;
 #define DTLS_MUTEX_INITIALIZER 0
 #define dtls_mutex_lock(a) *(a) = 1
 #define dtls_mutex_trylock(a) *(a) = 1
 #define dtls_mutex_unlock(a) *(a) = 0
 
 
-#else /* ! RIOT_VERSION && ! WITH_CONTIKI && ! WITH_ZEPHYR */
+#else /* ! RIOT_VERSION && ! WITH_CONTIKI && ! WITH_ZEPHYR && ! IS_WINDOWS */
 
 #include <pthread.h>
 
@@ -63,6 +65,6 @@ typedef pthread_mutex_t dtls_mutex_t;
 #define dtls_mutex_trylock(a) pthread_mutex_trylock(a)
 #define dtls_mutex_unlock(a) pthread_mutex_unlock(a)
 
-#endif /* ! RIOT_VERSION && ! WITH_CONTIKI */
+#endif /* ! RIOT_VERSION && ! WITH_CONTIKI && ! IS_WINDOWS */
 
 #endif /* _DTLS_MUTEX_H_ */

dtls_prng.c

@@ -30,6 +30,9 @@
 #elif defined (WITH_ZEPHYR)
 #include "platform-specific/dtls_prng_zephyr.c"
 
+#elif defined (IS_WINDOWS)
+#include "platform-specific/dtls_prng_win.c"
+
 #elif defined (WITH_POSIX)
 #include "platform-specific/dtls_prng_posix.c"