Const correctness.

[oweals/tinc.git] / src / mingw / device.c

diff --git a/src/mingw/device.c b/src/mingw/device.c
index 49b833abbe708f440aaf7af2307e676b22b1ffb2..321c51511d76a9d523399f5e95cd9b9e5822cdcf 100644 (file)
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -1,7 +1,7 @@
 /*
     device.c -- Interaction with Windows tap driver in a MinGW environment
     Copyright (C) 2002-2005 Ivo Timmermans,
-                  2002-2014 Guus Sliepen <guus@tinc-vpn.org>
+                  2002-2016 Guus Sliepen <guus@tinc-vpn.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -37,7 +37,7 @@ int device_fd = -1;
 static HANDLE device_handle = INVALID_HANDLE_VALUE;
 char *device = NULL;
 char *iface = NULL;
-static char *device_info = NULL;
+static const char *device_info = "Windows tap device";
 
 static uint64_t device_total_in = 0;
 static uint64_t device_total_out = 0;
@@ -66,17 +66,21 @@ static DWORD WINAPI tapreader(void *bla) {
                if(!status) {
                        if(GetLastError() == ERROR_IO_PENDING) {
                                WaitForSingleObject(r_overlapped.hEvent, INFINITE);
-                               if(!GetOverlappedResult(device_handle, &r_overlapped, &len, FALSE))
+
+                               if(!GetOverlappedResult(device_handle, &r_overlapped, &len, FALSE)) {
                                        continue;
+                               }
                        } else {
                                logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
-                                          device, strerror(errno));
+                                      device, strerror(errno));
                                errors++;
+
                                if(errors >= 10) {
                                        EnterCriticalSection(&mutex);
                                        running = false;
                                        LeaveCriticalSection(&mutex);
                                }
+
                                usleep(1000000);
                                continue;
                        }
@@ -113,6 +117,10 @@ static bool setup_device(void) {
        get_config_string(lookup_config(config_tree, "Device"), &device);
        get_config_string(lookup_config(config_tree, "Interface"), &iface);
 
+       if(device && iface) {
+               logger(LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
+       }
+
        /* Open registry and look for network adapters */
 
        if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
@@ -120,44 +128,51 @@ static bool setup_device(void) {
                return false;
        }
 
-       for (i = 0; ; i++) {
+       for(i = 0; ; i++) {
                len = sizeof(adapterid);
-               if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
+
+               if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL)) {
                        break;
+               }
 
                /* Find out more about this adapter */
 
                snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 
-                if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
+               if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2)) {
                        continue;
+               }
 
                len = sizeof(adaptername);
                err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 
                RegCloseKey(key2);
 
-               if(err)
+               if(err) {
                        continue;
+               }
 
                if(device) {
                        if(!strcmp(device, adapterid)) {
                                found = true;
                                break;
-                       } else
+                       } else {
                                continue;
+                       }
                }
 
                if(iface) {
                        if(!strcmp(iface, adaptername)) {
                                found = true;
                                break;
-                       } else
+                       } else {
                                continue;
+                       }
                }
 
                snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
                device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
+
                if(device_handle != INVALID_HANDLE_VALUE) {
                        found = true;
                        break;
@@ -171,11 +186,13 @@ static bool setup_device(void) {
                return false;
        }
 
-       if(!device)
+       if(!device) {
                device = xstrdup(adapterid);
+       }
 
-       if(!iface)
+       if(!iface) {
                iface = xstrdup(adaptername);
+       }
 
        /* Try to open the corresponding tap device */
 
@@ -183,7 +200,7 @@ static bool setup_device(void) {
                snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
                device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
        }
-       
+
        if(device_handle == INVALID_HANDLE_VALUE) {
                logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
                return false;
@@ -219,8 +236,6 @@ static bool setup_device(void) {
        status = true;
        DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 
-       device_info = "Windows tap device";
-
        logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 
        return true;
@@ -242,18 +257,20 @@ static bool write_packet(vpn_packet_t *packet) {
        static vpn_packet_t queue;
 
        ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
-                          packet->len, device_info);
+                               packet->len, device_info);
 
        /* Check if there is something in progress */
 
        if(queue.len) {
                DWORD size;
                BOOL success = GetOverlappedResult(device_handle, &w_overlapped, &size, FALSE);
+
                if(success) {
                        ResetEvent(&w_overlapped);
                        queue.len = 0;
                } else {
                        int err = GetLastError();
+
                        if(err != ERROR_IO_INCOMPLETE) {
                                ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error completing previously queued write: %s", winerror(err));
                                ResetEvent(&w_overlapped);
@@ -272,10 +289,12 @@ static bool write_packet(vpn_packet_t *packet) {
 
        if(!WriteFile(device_handle, queue.data, packet->len, &lenout, &w_overlapped)) {
                int err = GetLastError();
+
                if(err != ERROR_IO_PENDING) {
                        logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(err));
                        return false;
                }
+
                // Write is being done asynchronously.
                queue.len = packet->len;
        } else {