X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fmingw%2Fdevice.c;h=4b821df7378d1d8ad6c813fd0cff5a91c3b31a45;hp=33b13da60b89a9496f311c50f48757af9764ded7;hb=95921696a49d1eff058880c90a80efd208de959d;hpb=e57daac63b6f703af8e7c8209ef61a4d3b2180c3 diff --git a/src/mingw/device.c b/src/mingw/device.c index 33b13da6..4b821df7 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, - 2002-2013 Guus Sliepen + 2002-2014 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 @@ -38,29 +38,37 @@ 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 uint64_t device_total_in = 0; -static uint64_t device_total_out = 0; - extern char *myport; static void device_issue_read() { device_read_overlapped.Offset = 0; device_read_overlapped.OffsetHigh = 0; - int status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, NULL, &device_read_overlapped); + int status; + for (;;) { + DWORD len; + status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped); + if (!status) { + if (GetLastError() != ERROR_IO_PENDING) + logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info, + device, strerror(errno)); + break; + } - if(!status && GetLastError() != ERROR_IO_PENDING) { - logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info, - device, strerror(errno)); + device_read_packet.len = len; + device_read_packet.priority = 0; + route(myself, &device_read_packet); } } -static void device_handle_read(void *data) { +static void device_handle_read(void *data, int flags) { ResetEvent(device_read_overlapped.hEvent); DWORD len; @@ -89,7 +97,6 @@ static bool setup_device(void) { bool found = false; int err; - HANDLE thread; get_config_string(lookup_config(config_tree, "Device"), &device); get_config_string(lookup_config(config_tree, "Interface"), &iface); @@ -181,12 +188,6 @@ static bool setup_device(void) { overwrite_mac = 1; } - /* Start the tap reader */ - - io_add_event(&device_read_io, device_handle_read, NULL, CreateEvent(NULL, TRUE, FALSE, NULL)); - device_read_overlapped.hEvent = device_read_io.event; - device_issue_read(); - device_info = "Windows tap device"; logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info); @@ -196,22 +197,45 @@ static bool setup_device(void) { static void enable_device(void) { logger(DEBUG_ALWAYS, LOG_INFO, "Enabling %s", device_info); + ULONG status = 1; DWORD len; DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL); + + /* We don't use the write event directly, but GetOverlappedResult() does, internally. */ + + device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); + device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); + + io_add_event(&device_read_io, device_handle_read, NULL, device_read_overlapped.hEvent); + device_issue_read(); } static void disable_device(void) { logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info); - ULONG status = 0; + + io_del(&device_read_io); + 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. */ + 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); + + ULONG status = 0; DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL); } static void close_device(void) { - io_del(&device_read_io); - CancelIo(device_handle); - CloseHandle(device_read_overlapped.hEvent); CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE; free(device); device = NULL; @@ -225,18 +249,33 @@ static bool read_packet(vpn_packet_t *packet) { 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); - if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) { + 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)) { + int log_level = (GetLastError() == ERROR_IO_INCOMPLETE) ? DEBUG_TRAFFIC : DEBUG_ALWAYS; + logger(log_level, LOG_ERR, "Error while checking previous write to %s %s: %s", device_info, device, winerror(GetLastError())); + return false; + } + } + + /* Copy the packet, since the write operation might still be ongoing after we return. */ + + memcpy(&device_write_packet, packet, sizeof *packet); + + if(WriteFile(device_handle, DATA(&device_write_packet), device_write_packet.len, &outlen, &device_write_overlapped)) + 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())); return false; } - device_total_out += packet->len; - return true; }