bootloader: on Windows, avoid using ntohl() from ws2_32 library

On Windows, use built-in byte-swap macros instead of ntohl(), which
is available from winsock2 library. Using the latter requires the
bootloader to be linked against the winsock2 library, which may have
other unintended consequences.

On all other platforms, continue using ntohl() for now, but hide it
behind the pyi_be32toh() macro.

bootloader/src/pyi_archive.c

@@ -16,15 +16,28 @@
  */
 
 #ifdef _WIN32
-/* TODO verify windows includes */
-    #include <winsock.h>  /* ntohl */
+    #if BYTE_ORDER == LITTLE_ENDIAN
+        #if defined(_MSC_VER)
+            #include <stdlib.h>
+            #define pyi_be32toh(x) _byteswap_ulong(x)
+        #elif defined(__GNUC__) || defined(__clang__)
+            #define pyi_be32toh(x) __builtin_bswap32(x)
+        #else
+            #error Unsupported compiler
+        #endif
+    #elif BYTE_ORDER == BIG_ENDIAN
+        #define pyi_be32toh(x) (x)
+    #else
+        #error Unsupported byte order
+    #endif
 #else
     #ifdef __FreeBSD__
 /* freebsd issue #188316 */
         #include <arpa/inet.h>  /* ntohl */
     #else
         #include <netinet/in.h>  /* ntohl */
     #endif
+    #define pyi_be32toh(x) ntohl(x)
     #include <stdlib.h>   /* malloc */
     #include <string.h>   /* strncmp, strcpy, strcat */
     #include <sys/stat.h> /* fchmod */
@@ -266,10 +279,10 @@ pyi_arch_find_cookie(ARCHIVE_STATUS *status, int search_end)
             memcpy(&status->cookie, search_ptr, sizeof(COOKIE));
 
             /* Fix endianess of COOKIE fields */
-            status->cookie.len = ntohl(status->cookie.len);
-            status->cookie.TOC = ntohl(status->cookie.TOC);
-            status->cookie.TOClen = ntohl(status->cookie.TOClen);
-            status->cookie.pyvers = ntohl(status->cookie.pyvers);
+            status->cookie.len = pyi_be32toh(status->cookie.len);
+            status->cookie.TOC = pyi_be32toh(status->cookie.TOC);
+            status->cookie.TOClen = pyi_be32toh(status->cookie.TOClen);
+            status->cookie.pyvers = pyi_be32toh(status->cookie.pyvers);
 
             /* From the cookie, calculate the archive start */
             status->pkgstart = search_start + sizeof(COOKIE) + (search_ptr - buf) - status->cookie.len;
@@ -389,10 +402,10 @@ _pyi_arch_fix_toc_endianess(ARCHIVE_STATUS *status)
     TOC *ptoc = status->tocbuff;
     while (ptoc < status->tocend) {
         /* Fixup the current entry */
-        ptoc->structlen = ntohl(ptoc->structlen);
-        ptoc->pos = ntohl(ptoc->pos);
-        ptoc->len = ntohl(ptoc->len);
-        ptoc->ulen = ntohl(ptoc->ulen);
+        ptoc->structlen = pyi_be32toh(ptoc->structlen);
+        ptoc->pos = pyi_be32toh(ptoc->pos);
+        ptoc->len = pyi_be32toh(ptoc->len);
+        ptoc->ulen = pyi_be32toh(ptoc->ulen);
         /* Jump to next entry; with the current entry fixed up, we can
          * use pyi_arch_increment_toc_ptr() */
         ptoc = pyi_arch_increment_toc_ptr(status, ptoc);

bootloader/src/pyi_global.h

@@ -51,6 +51,7 @@ typedef int bool;
 
 /* Type for dynamic library. */
 #ifdef _WIN32
+    #include <windows.h>  /* HINSTANCE */
     #define dylib_t   HINSTANCE
 #else
     #define dylib_t   void *

bootloader/tests/wscript

@@ -17,10 +17,9 @@ def build(ctx):
 
     def test_program(name):
         if ctx.env.DEST_OS == 'win32':
-            # WS2_32: ntohl()
             # Z: inflate*()
             # ADVAPI32: ConvertStringSecurityDescriptorToSecurityDescriptorW()
-            extra_libs=['ADVAPI32', 'WS2_32', 'Z']
+            extra_libs=['ADVAPI32', 'Z']
         else:
             extra_libs=[]
         ctx.program(

bootloader/wscript

@@ -556,14 +556,13 @@ def configure(ctx):
 
     if ctx.env.DEST_OS == 'win32':
         if ctx.env.CC_NAME == 'msvc':
-            ctx.check_libs_msvc('user32 comctl32 kernel32 advapi32 ws2_32',
+            ctx.check_libs_msvc('user32 comctl32 kernel32 advapi32',
                                 mandatory=True)
         else:
             ctx.check_cc(lib='user32', mandatory=True)
             ctx.check_cc(lib='comctl32', mandatory=True)
             ctx.check_cc(lib='kernel32', mandatory=True)
             ctx.check_cc(lib='advapi32', mandatory=True)
-            ctx.check_cc(lib='ws2_32', mandatory=True)
     else:
         # Mac OS X and FreeBSD do not need libdl.
         # https://stackoverflow.com/questions/20169660/where-is-libdl-so-on-mac-os-x
@@ -750,7 +749,7 @@ def build(ctx):
             source=['src/main.c', icon_rc],
             target=exe_name,
             install_path=install_path,
-            use='OBJECTS USER32 COMCTL32 KERNEL32 ADVAPI32 WS2_32 Z',
+            use='OBJECTS USER32 COMCTL32 KERNEL32 ADVAPI32 Z',
             includes='src windows zlib',
             features=features,
         )