Clean up default vpnc-script handling for Windows

We automatically prepend the current executable's path to the script
name if it's relative, and run it in 'cscript.exe'.

Perhaps it would be nicer if we determined whether the path was relative
or not in autoconf, rather than at runtime.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

configure.ac

@@ -72,27 +72,35 @@ AC_ARG_WITH([vpnc-script],
 	  [default location of vpnc-script helper])])
 
 if test "$with_vpnc_script" = "yes" || test "$with_vpnc_script" = ""; then
-   with_vpnc_script=/etc/vpnc/vpnc-script
-   if ! test -x "$with_vpnc_script"; then
-      AC_MSG_ERROR([${with_vpnc_script} does not seem to be executable.]
-    [OpenConnect will not function correctly without a vpnc-script.]
-    [See http://www.infradead.org/openconnect/vpnc-script.html for more details.]
-    []
-    [If you are building a distribution package, please ensure that your]
-    [packaging is correct, and that a vpnc-script will be installed when the]
-    [user installs your package. You should provide a --with-vpnc-script=]
-    [argument to this configure script, giving the full path where the script]
-    [will be installed.]
-    []
-    [The standard location is ${with_vpnc_script}. To bypass this error and]
-    [build OpenConnect to use the script from this location, even though it's]
-    [not present at the time you are building OpenConnect, pass the argument]
-    ["--with-vpnc-script=${with_vpnc_script}"])
-  fi
+   if test "$have_win" = "yes"; then
+      with_vpnc_script=vpnc-script-win.js
+   else
+      with_vpnc_script=/etc/vpnc/vpnc-script
+      if ! test -x "$with_vpnc_script"; then
+	 AC_MSG_ERROR([${with_vpnc_script} does not seem to be executable.]
+	     [OpenConnect will not function correctly without a vpnc-script.]
+             [See http://www.infradead.org/openconnect/vpnc-script.html for more details.]
+             []
+             [If you are building a distribution package, please ensure that your]
+             [packaging is correct, and that a vpnc-script will be installed when the]
+             [user installs your package. You should provide a --with-vpnc-script=]
+             [argument to this configure script, giving the full path where the script]
+             [will be installed.]
+             []
+             [The standard location is ${with_vpnc_script}. To bypass this error and]
+             [build OpenConnect to use the script from this location, even though it's]
+             [not present at the time you are building OpenConnect, pass the argument]
+             ["--with-vpnc-script=${with_vpnc_script}"])
+     fi
+   fi
 elif test "$with_vpnc_script" = "no"; then
    AC_ERROR([You cannot disable vpnc-script.]
    [OpenConnect will not function correctly without it.]
    [See http://www.infradead.org/openconnect/vpnc-script.html])
+elif test "$have_win" = "yes"; then
+   # Oh Windows how we hate thee. If user specifies a vpnc-script and it contains
+   # backslashes, double them all up to survive escaping.
+   with_vpnc_script="$(echo "${with_vpnc_script}" | sed s/\\\\/\\\\\\\\/g)"
 fi
 
 AC_DEFINE_UNQUOTED(DEFAULT_VPNCSCRIPT, "${with_vpnc_script}")
@@ -149,7 +157,7 @@ AC_SUBST(WFLAGS, [$WFLAGS])
 
 if test "$have_win" = yes; then
    # Checking "properly" for __attribute__((dllimport,stdcall)) functions is non-trivial
-   LIBS="$LIBS -lws2_32"
+   LIBS="$LIBS -lws2_32 -lshlwapi"
 else
    AC_CHECK_FUNC(socket, [], AC_CHECK_LIB(socket, socket, [], AC_ERROR(Cannot find socket() function)))
 fi

main.c

@@ -288,6 +288,31 @@ static void print_build_opts(void)
 #endif
 }
 
+#ifndef _WIN32
+static const char default_vpncscript[] = DEFAULT_VPNCSCRIPT;
+#else
+#include <shlwapi.h>
+static const char *default_vpncscript;
+static void set_default_vpncscript(void)
+{
+	if (PathIsRelative(DEFAULT_VPNCSCRIPT)) {
+		char *c = strrchr(_pgmptr, '\\');
+		if (!c) {
+			fprintf(stderr, _("Cannot process this executable path \"%s\""),
+				_pgmptr);
+			exit(1);
+		}
+		if (asprintf((char **)&default_vpncscript, "cscript %.*s%s",
+			     (c - _pgmptr + 1), _pgmptr, DEFAULT_VPNCSCRIPT) < 0) {
+			fprintf(stderr, _("Allocation for vpnc-script path failed\n"));
+			exit(1);
+		}
+	} else {
+		default_vpncscript = "cscript " DEFAULT_VPNCSCRIPT;
+	}
+}
+#endif
+
 static void usage(void)
 {
 	printf(_("Usage:  openconnect [options] <server>\n"));
@@ -332,7 +357,7 @@ static void usage(void)
 	printf("  -q, --quiet                     %s\n", _("Less output"));
 	printf("  -Q, --queue-len=LEN             %s\n", _("Set packet queue limit to LEN pkts"));
 	printf("  -s, --script=SCRIPT             %s\n", _("Shell command line for using a vpnc-compatible config script"));
-	printf("                                  %s: \"%s\"\n", _("default"), DEFAULT_VPNCSCRIPT);
+	printf("                                  %s: \"%s\"\n", _("default"), default_vpncscript);
 #ifndef _WIN32
 	printf("  -S, --script-tun                %s\n", _("Pass traffic to 'script' program, not tun"));
 #endif
@@ -610,7 +635,9 @@ int main(int argc, char **argv)
 	}
 
 	vpninfo->cbdata = vpninfo;
-#ifndef _WIN32
+#ifdef _WIN32
+	set_default_vpncscript();
+#else
 	if (!uname(&utsbuf)) {
 		free(vpninfo->localname);
 		vpninfo->localname = xstrdup(utsbuf.nodename);
@@ -1005,7 +1032,7 @@ int main(int argc, char **argv)
 	}
 
 	if (!vpnc_script)
-		vpnc_script = xstrdup(DEFAULT_VPNCSCRIPT);
+		vpnc_script = xstrdup(default_vpncscript);
 #ifndef _WIN32
 	if (script_tun) {
 		if (openconnect_setup_tun_script(vpninfo, vpnc_script)) {

openconnect.8.in

@@ -230,9 +230,13 @@ compatible with the
 .B vpnc\-script
 which is shipped with the "vpnc" VPN client. See
 .I http://www.infradead.org/openconnect/vpnc-script.html
-for more information. This version of OpenConnect is configured to use
-.B @DEFAULT_VPNCSCRIPT@
-by default.
+for more information. This version of OpenConnect is configured to
+use \fB@DEFAULT_VPNCSCRIPT@\fR by default.
+
+On Windows, a relative directory for the default script will be handled as
+starting from the directory that the openconnect executable is running from,
+rather than the current directory. The script will be invoked with the
+command-based script host \fBcscript.exe\fR.
 .TP
 .B \-S,\-\-script\-tun
 Pass traffic to 'script' program over a UNIX socket, instead of to a kernel