X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fmingw%2Fdevice.c;h=bf8ae13779cc3375bc1d936a14eecbfadf6c4f6e;hp=253b95d1b8ec8062cb0e6845651c624dc92018a2;hb=d6b45d005530496e48325a6174ecdd889a17bfc1;hpb=0f328d9d2853ca723ff3205f39bb22207d21a932 diff --git a/src/mingw/device.c b/src/mingw/device.c index 253b95d1..bf8ae137 100644 --- 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 + 2002-2018 Guus Sliepen 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 @@ -38,25 +38,29 @@ int device_fd = -1; static HANDLE device_handle = INVALID_HANDLE_VALUE; static io_t device_read_io; static OVERLAPPED device_read_overlapped; +static OVERLAPPED device_write_overlapped; static vpn_packet_t device_read_packet; +static vpn_packet_t device_write_packet; char *device = NULL; char *iface = NULL; -static char *device_info = NULL; +static const char *device_info = "Windows tap device"; extern char *myport; static void device_issue_read() { - device_read_overlapped.Offset = 0; - device_read_overlapped.OffsetHigh = 0; - int status; - for (;;) { + + for(;;) { + ResetEvent(device_read_overlapped.hEvent); + DWORD len; status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped); - if (!status) { - if (GetLastError() != ERROR_IO_PENDING) + + if(!status) { + if(GetLastError() != ERROR_IO_PENDING) logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info, - device, strerror(errno)); + device, strerror(errno)); + break; } @@ -67,12 +71,20 @@ static void device_issue_read() { } static void device_handle_read(void *data, int flags) { - ResetEvent(device_read_overlapped.hEvent); + (void)data; + (void)flags; DWORD len; - if (!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) { + + if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) { logger(DEBUG_ALWAYS, LOG_ERR, "Error getting read result from %s %s: %s", device_info, - device, strerror(errno)); + device, strerror(errno)); + + if(GetLastError() != ERROR_IO_INCOMPLETE) { + /* Must reset event or it will keep firing. */ + ResetEvent(device_read_overlapped.hEvent); + } + return; } @@ -99,6 +111,10 @@ 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(DEBUG_ALWAYS, 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)) { @@ -106,44 +122,51 @@ static bool setup_device(void) { return false; } - for (i = 0; ; i++) { - len = sizeof adapterid; - if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL)) + for(i = 0; ; i++) { + len = sizeof(adapterid); + + 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); + 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; + 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); + 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; @@ -157,16 +180,18 @@ 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 */ if(device_handle == INVALID_HANDLE_VALUE) { - snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device); + 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); } @@ -180,15 +205,24 @@ static bool setup_device(void) { { ULONG info[3] = {0}; DWORD len; - if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_VERSION, &info, sizeof info, &info, sizeof info, &len, NULL)) + + if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_VERSION, &info, sizeof(info), &info, sizeof(info), &len, NULL)) { logger(DEBUG_ALWAYS, LOG_WARNING, "Could not get version information from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError())); - else + } else { logger(DEBUG_ALWAYS, LOG_INFO, "TAP-Windows driver version: %lu.%lu%s", info[0], info[1], info[2] ? " (DEBUG)" : ""); + + /* Warn if using >=9.21. This is because starting from 9.21, TAP-Win32 seems to use a different, less efficient write path. */ + if(info[0] == 9 && info[1] >= 21) + logger(DEBUG_ALWAYS, LOG_WARNING, + "You are using the newer (>= 9.0.0.21, NDIS6) series of TAP-Win32 drivers. " + "Using these drivers with tinc is not recommended as it can result in poor performance. " + "You might want to revert back to 9.0.0.9 instead."); + } } /* Get MAC address from tap device */ - if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) { + if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) { logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError())); return false; } @@ -201,6 +235,9 @@ static bool setup_device(void) { logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info); + device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); + device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); + return true; } @@ -209,10 +246,11 @@ static void enable_device(void) { ULONG status = 1; DWORD len; - DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL); + DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL); - io_add_event(&device_read_io, device_handle_read, NULL, CreateEvent(NULL, TRUE, FALSE, NULL)); - device_read_overlapped.hEvent = device_read_io.event; + /* We don't use the write event directly, but GetOverlappedResult() does, internally. */ + + io_add_event(&device_read_io, device_handle_read, NULL, device_read_overlapped.hEvent); device_issue_read(); } @@ -220,35 +258,89 @@ static void disable_device(void) { logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info); io_del(&device_read_io); - CancelIo(device_handle); - CloseHandle(device_read_overlapped.hEvent); ULONG status = 0; DWORD len; - DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL); + DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL); + + /* Note that we don't try to cancel ongoing I/O here - we just stop listening. + This is because some TAP-Win32 drivers don't seem to handle cancellation very well, + especially when combined with other events such as the computer going to sleep - cases + were observed where the GetOverlappedResult() would just block indefinitely and never + return in that case. */ } static void close_device(void) { - CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE; + CancelIo(device_handle); + + /* According to MSDN, CancelIo() does not necessarily wait for the operation to complete. + To prevent race conditions, make sure the operation is complete + before we close the event it's referencing. */ - free(device); device = NULL; - free(iface); iface = NULL; + DWORD len; + + if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED) { + logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s read to cancel: %s", device_info, device, winerror(GetLastError())); + } + + if(device_write_packet.len > 0 && !GetOverlappedResult(device_handle, &device_write_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED) { + logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s write to cancel: %s", device_info, device, winerror(GetLastError())); + } + + device_write_packet.len = 0; + + CloseHandle(device_read_overlapped.hEvent); + CloseHandle(device_write_overlapped.hEvent); + + CloseHandle(device_handle); + device_handle = INVALID_HANDLE_VALUE; + + free(device); + device = NULL; + free(iface); + iface = NULL; device_info = NULL; } static bool read_packet(vpn_packet_t *packet) { + (void)packet; return false; } static bool write_packet(vpn_packet_t *packet) { DWORD outlen; - OVERLAPPED overlapped = {0}; logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s", - packet->len, device_info); + packet->len, device_info); + + if(device_write_packet.len > 0) { + /* Make sure the previous write operation is finished before we start the next one; + otherwise we end up with multiple write ops referencing the same OVERLAPPED structure, + which according to MSDN is a no-no. */ + + if(!GetOverlappedResult(device_handle, &device_write_overlapped, &outlen, FALSE)) { + if(GetLastError() != ERROR_IO_INCOMPLETE) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error completing previously queued write to %s %s: %s", device_info, device, winerror(GetLastError())); + } else { + logger(DEBUG_TRAFFIC, LOG_ERR, "Previous overlapped write to %s %s still in progress", device_info, device); + // drop this packet + return true; + } + } + } + + /* Copy the packet, since the write operation might still be ongoing after we return. */ + + memcpy(&device_write_packet, packet, sizeof(*packet)); + + ResetEvent(device_write_overlapped.hEvent); - if(!WriteFile(device_handle, DATA(packet), packet->len, &outlen, &overlapped)) { + if(WriteFile(device_handle, DATA(&device_write_packet), device_write_packet.len, &outlen, &device_write_overlapped)) { + // Write was completed immediately. + device_write_packet.len = 0; + } else if(GetLastError() != ERROR_IO_PENDING) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError())); + device_write_packet.len = 0; return false; }