From b47c17bcdeb70b63ad9346dc97ba575597cbd803 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Tue, 15 Sep 2009 22:59:01 +0200 Subject: [PATCH] Use a mutex to allow the TAP reader to process packets faster on Windows. The TAP-Win32 device is not a socket, and select() under Windows only works with sockets. Tinc used a separate thread to read from the TAP-Win32 device, and passed this via a local socket to the main thread which could then select() from it. We now use a global mutex, which is only unlocked when the main thread is waiting for select(), to allow the TAP reader thread to process packets directly. --- src/mingw/device.c | 126 ++++----------------------------------------- src/net.c | 11 +++- src/net.h | 2 + src/tincd.c | 3 ++ 4 files changed, 25 insertions(+), 117 deletions(-) diff --git a/src/mingw/device.c b/src/mingw/device.c index e025cf7..fa13433 100644 --- a/src/mingw/device.c +++ b/src/mingw/device.c @@ -34,7 +34,7 @@ #include "mingw/common.h" -int device_fd = 0; +int device_fd = -1; static HANDLE device_handle = INVALID_HANDLE_VALUE; char *device = NULL; char *iface = NULL; @@ -45,63 +45,24 @@ static int device_total_out = 0; extern char *myport; -static struct packetbuf { - uint8_t data[MTU]; - length_t len; -} *bufs; - -static int nbufs = 64; - static DWORD WINAPI tapreader(void *bla) { - int sock, err, status; - struct addrinfo *ai; - struct addrinfo hint = { - .ai_family = AF_UNSPEC, - .ai_socktype = SOCK_STREAM, - .ai_protocol = IPPROTO_TCP, - .ai_flags = 0, - }; - unsigned char bufno = 0; + int status; long len; OVERLAPPED overlapped; - - /* Open a socket to the parent process */ - - err = getaddrinfo(NULL, myport, &hint, &ai); - - if(err || !ai) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo", gai_strerror(errno)); - return -1; - } - - sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP); - - if(sock < 0) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "socket", strerror(errno)); - freeaddrinfo(ai); - return -1; - } - - if(connect(sock, ai->ai_addr, ai->ai_addrlen)) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "connect", strerror(errno)); - freeaddrinfo(ai); - return -1; - } - - freeaddrinfo(ai); + vpn_packet_t packet; logger(LOG_DEBUG, _("Tap reader running")); /* Read from tap device and send to parent */ overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); - + for(;;) { overlapped.Offset = 0; overlapped.OffsetHigh = 0; ResetEvent(overlapped.hEvent); - status = ReadFile(device_handle, bufs[bufno].data, MTU, &len, &overlapped); + status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped); if(!status) { if(GetLastError() == ERROR_IO_PENDING) { @@ -115,11 +76,11 @@ static DWORD WINAPI tapreader(void *bla) { } } - bufs[bufno].len = len; - if(send(sock, &bufno, 1, 0) <= 0) - return -1; - if(++bufno >= nbufs) - bufno = 0; + EnterCriticalSection(&mutex); + packet.len = len; + packet.priority = 0; + route(myself, &packet); + LeaveCriticalSection(&mutex); } } @@ -240,44 +201,6 @@ bool setup_device(void) overwrite_mac = 1; } - /* Set up ringbuffer */ - - get_config_int(lookup_config(config_tree, "RingBufferSize"), &nbufs); - if(nbufs <= 1) - nbufs = 1; - else if(nbufs > 256) - nbufs = 256; - - bufs = xmalloc_and_zero(nbufs * sizeof *bufs); - - /* Create a listening socket */ - - err = getaddrinfo(NULL, myport, &hint, &ai); - - if(err || !ai) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo", gai_strerror(errno)); - return false; - } - - sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP); - - if(sock < 0) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "socket", strerror(errno)); - return false; - } - - if(bind(sock, ai->ai_addr, ai->ai_addrlen)) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "bind", strerror(errno)); - return false; - } - - freeaddrinfo(ai); - - if(listen(sock, 1)) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "listen", strerror(errno)); - return false; - } - /* Start the tap reader */ thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL); @@ -287,15 +210,6 @@ bool setup_device(void) return false; } - /* Wait for the tap reader to connect back to us */ - - if((device_fd = accept(sock, NULL, 0)) == -1) { - logger(LOG_ERR, _("System call `%s' failed: %s"), "accept", strerror(errno)); - return false; - } - - closesocket(sock); - /* Set media status for newer TAP-Win32 devices */ status = true; @@ -320,25 +234,7 @@ void close_device(void) bool read_packet(vpn_packet_t *packet) { - unsigned char bufno; - - cp(); - - if((recv(device_fd, &bufno, 1, 0)) <= 0) { - logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info, - device, strerror(errno)); - return false; - } - - packet->len = bufs[bufno].len; - memcpy(packet->data, bufs[bufno].data, bufs[bufno].len); - - device_total_in += packet->len; - - ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len, - device_info); - - return true; + return false; } bool write_packet(vpn_packet_t *packet) diff --git a/src/net.c b/src/net.c index c893f1e..82b0ede 100644 --- a/src/net.c +++ b/src/net.c @@ -149,7 +149,8 @@ static int build_fdset(fd_set *readset, fd_set *writeset) max = listen_socket[i].udp; } - FD_SET(device_fd, readset); + if(device_fd >= 0) + FD_SET(device_fd, readset); if(device_fd > max) max = device_fd; @@ -294,7 +295,7 @@ static void check_network_activity(fd_set * readset, fd_set * writeset) cp(); /* check input from kernel */ - if(FD_ISSET(device_fd, readset)) { + if(device_fd >= 0 && FD_ISSET(device_fd, readset)) { if(read_packet(&packet)) { packet.priority = 0; route(myself, &packet); @@ -378,7 +379,13 @@ int main_loop(void) maxfd = build_fdset(&readset, &writeset); +#ifdef HAVE_MINGW + LeaveCriticalSection(&mutex); +#endif r = select(maxfd + 1, &readset, &writeset, NULL, &tv); +#ifdef HAVE_MINGW + EnterCriticalSection(&mutex); +#endif if(r < 0) { if(errno != EINTR && errno != EAGAIN) { diff --git a/src/net.h b/src/net.h index 0f70a4b..ff32b73 100644 --- a/src/net.h +++ b/src/net.h @@ -143,6 +143,8 @@ extern void send_mtu_probe(struct node_t *); #ifndef HAVE_MINGW #define closesocket(s) close(s) +#else +extern CRITICAL_SECTION mutex; #endif #endif /* __TINC_NET_H__ */ diff --git a/src/tincd.c b/src/tincd.c index a13e266..b2e055c 100644 --- a/src/tincd.c +++ b/src/tincd.c @@ -115,6 +115,7 @@ static struct option const long_options[] = { #ifdef HAVE_MINGW static struct WSAData wsa_state; +CRITICAL_SECTION mutex; #endif static void usage(bool status) @@ -568,6 +569,8 @@ int main(int argc, char **argv) int main2(int argc, char **argv) { + InitializeCriticalSection(&mutex); + EnterCriticalSection(&mutex); #endif if(!detach()) -- 2.25.1