From 6096fb0e49e6dfed4f6a0f3363d4873e528eabef Mon Sep 17 00:00:00 2001
From: David Woodhouse <David.Woodhouse@intel.com>
Date: Sat, 24 Sep 2016 00:09:07 +0100
Subject: [PATCH] Add TUNIDX for Windows vpnc-script

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---
 configure.ac           |  2 +-
 library.c              |  4 +++
 openconnect-internal.h |  2 +-
 tun-win32.c            | 62 ++++++++++++++++++++++++++++++++++++++++++
 www/changelog.xml      |  1 +
 5 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 118a740a..fcb2bad9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -170,7 +170,7 @@ AC_SUBST(WFLAGS, [$WFLAGS])
 
 if test "$have_win" = yes; then
    # Checking "properly" for __attribute__((dllimport,stdcall)) functions is non-trivial
-   LIBS="$LIBS -lws2_32 -lshlwapi -lsecur32"
+   LIBS="$LIBS -lws2_32 -lshlwapi -lsecur32 -liphlpapi"
 else
    AC_CHECK_FUNC(socket, [], AC_CHECK_LIB(socket, socket, [], AC_ERROR(Cannot find socket() function)))
 fi
diff --git a/library.c b/library.c
index 5e22a6d9..9cce027e 100644
--- a/library.c
+++ b/library.c
@@ -840,6 +840,10 @@ int openconnect_setup_tun_device(struct openconnect_info *vpninfo,
 	if (tun_fd < 0)
 		return tun_fd;
 
+#ifdef _WIN32
+	if (vpninfo->tun_idx != -1)
+		script_setenv_int(vpninfo, "TUNIDX", vpninfo->tun_idx);
+#endif
 	legacy_ifname = openconnect_utf8_to_legacy(vpninfo, vpninfo->ifname);
 	script_setenv(vpninfo, "TUNDEV", legacy_ifname, 0);
 	if (legacy_ifname != vpninfo->ifname)
diff --git a/openconnect-internal.h b/openconnect-internal.h
index 10cc909a..e44a549c 100644
--- a/openconnect-internal.h
+++ b/openconnect-internal.h
@@ -589,7 +589,7 @@ struct openconnect_info {
 #ifdef _WIN32
 	HANDLE tun_fh;
 	OVERLAPPED tun_rd_overlap, tun_wr_overlap;
-	int tun_rd_pending;
+	int tun_idx, tun_rd_pending;
 #else
 	int tun_fd;
 #endif
diff --git a/tun-win32.c b/tun-win32.c
index b5f6f83c..9bc98815 100644
--- a/tun-win32.c
+++ b/tun-win32.c
@@ -20,6 +20,7 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #include <winioctl.h>
+#include <iphlpapi.h>
 
 #include <errno.h>
 #include <stdio.h>
@@ -155,6 +156,65 @@ static intptr_t search_taps(struct openconnect_info *vpninfo, tap_callback *cb,
 	return ret;
 }
 
+static int get_adapter_index(struct openconnect_info *vpninfo, char *guid)
+{
+	struct oc_text_buf *buf = buf_alloc();
+	IP_ADAPTER_INFO *adapter;
+	void *adapters_buf;
+	ULONG idx;
+	DWORD status;
+	int ret = -EINVAL;
+
+	vpninfo->tun_idx = -1;
+
+	buf_append_utf16le(buf, "\\device\\tcpip_");
+	buf_append_utf16le(buf, guid);
+	if (buf_error(buf)) {
+		/* If we didn't manage to malloc for this, we're never
+		 * going to manage for GetAdaptersInfo(). Give up. */
+		return buf_free(buf);
+	}
+
+	status = GetAdapterIndex((void *)buf->data, &idx);
+	buf_free(buf);
+	if (status == NO_ERROR) {
+		vpninfo->tun_idx = idx;
+		return 0;
+	} else {
+		char *errstr = openconnect__win32_strerror(status);
+		vpn_progress(vpninfo, PRG_INFO,
+			     _("GetAdapterIndex() failed: %s\nFalling back to GetAdaptersInfo()\n"),
+			     errstr);
+		free(errstr);
+	}
+	idx = 0;
+	status = GetAdaptersInfo(NULL, &idx);
+	if (status != ERROR_BUFFER_OVERFLOW)
+		return -EIO;
+	adapters_buf = malloc(idx);
+	if (!adapters_buf)
+		return -ENOMEM;
+	status = GetAdaptersInfo(adapters_buf, &idx);
+	if (status != NO_ERROR) {
+		char *errstr = openconnect__win32_strerror(status);
+		vpn_progress(vpninfo, PRG_ERR, _("GetAdaptersInfo() failed: %s\n"), errstr);
+		free(errstr);
+		free(adapters_buf);
+		return -EIO;
+	}
+
+	for (adapter = adapters_buf; adapter; adapter = adapter->Next) {
+		if (!strcmp(adapter->AdapterName, guid)) {
+			vpninfo->tun_idx = adapter->Index;
+			ret = 0;
+			break;
+		}
+	}
+
+	free(adapters_buf);
+	return ret;
+}
+
 static intptr_t open_tun(struct openconnect_info *vpninfo, char *guid, char *name)
 {
 	char devname[80];
@@ -227,6 +287,8 @@ static intptr_t open_tun(struct openconnect_info *vpninfo, char *guid, char *nam
 	if (!vpninfo->ifname)
 		vpninfo->ifname = strdup(name);
 
+	get_adapter_index(vpninfo, guid);
+
 	return (intptr_t)tun_fh;
 }
 
diff --git a/www/changelog.xml b/www/changelog.xml
index e9e8fa69..fc264d70 100644
--- a/www/changelog.xml
+++ b/www/changelog.xml
@@ -15,6 +15,7 @@
 <ul>
    <li><b>OpenConnect HEAD</b>
      <ul>
+       <li>Add <tt>TUNIDX</tt> environment variable on Windows.</li>
        <li>Fix compatibility with Pulse Secure 8.2R5.</li>
        <li>Fix IPv6 support in Solaris.</li>
        <li>Support DTLS automatic negotiation.</li>