| /* |
| Copyright (c) 2012-2013 Martin Sustrik All rights reserved. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), |
| to deal in the Software without restriction, including without limitation |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| and/or sell copies of the Software, and to permit persons to whom |
| the Software is furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included |
| in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| IN THE SOFTWARE. |
| */ |
| |
| #define NN_EFD_PORT 5907 |
| #define NN_EFD_RETRIES 1000 |
| |
| #include "err.h" |
| #include "fast.h" |
| #include "int.h" |
| |
| #include <string.h> |
| |
| int nn_efd_init (struct nn_efd *self) |
| { |
| SECURITY_ATTRIBUTES sa = {0}; |
| SECURITY_DESCRIPTOR sd; |
| BOOL brc; |
| HANDLE sync; |
| DWORD dwrc; |
| SOCKET listener; |
| int rc; |
| struct sockaddr_in addr; |
| int addrlen; |
| BOOL reuseaddr; |
| BOOL nodelay; |
| u_long nonblock; |
| int i; |
| |
| /* Make the following critical section accessible to everyone. */ |
| sa.nLength = sizeof (sa); |
| sa.bInheritHandle = FALSE; |
| brc = InitializeSecurityDescriptor (&sd, SECURITY_DESCRIPTOR_REVISION); |
| win_assert (brc); |
| brc = SetSecurityDescriptorDacl(&sd, TRUE, (PACL) NULL, FALSE); |
| win_assert (brc); |
| sa.lpSecurityDescriptor = &sd; |
| |
| /* This function has to be enclosed in a system-wide critical section |
| so that two instances of the library don't accidentally create an efd |
| crossing the process boundary. |
| CAUTION: This critical section has machine-wide scope. Thus, it must |
| be properly exited even before crashing the process by an assertion. */ |
| sync = CreateEvent (&sa, FALSE, TRUE, "Global\\nanomsg-port-sync"); |
| win_assert (sync != NULL); |
| |
| /* Enter the critical section. */ |
| dwrc = WaitForSingleObject (sync, INFINITE); |
| nn_assert (dwrc == WAIT_OBJECT_0); |
| |
| /* Unfortunately, on Windows the only way to send signal to a file |
| descriptor (SOCKET) is to create a full-blown TCP connecting on top of |
| the loopback interface. */ |
| self->w = INVALID_SOCKET; |
| self->r = INVALID_SOCKET; |
| |
| /* Create listening socket. */ |
| listener = socket (AF_INET, SOCK_STREAM, 0); |
| if (nn_slow (listener == SOCKET_ERROR)) |
| goto wsafail; |
| brc = SetHandleInformation ((HANDLE) listener, HANDLE_FLAG_INHERIT, 0); |
| win_assert (brc); |
| |
| /* This prevents subsequent attempts to create a signaler to fail bacause |
| of "TCP port in use" problem. */ |
| reuseaddr = 1; |
| rc = setsockopt (listener, SOL_SOCKET, SO_REUSEADDR, |
| (char*) &reuseaddr, sizeof (reuseaddr)); |
| if (nn_slow (rc == SOCKET_ERROR)) |
| goto wsafail; |
| |
| /* Bind the listening socket to the local port. */ |
| memset (&addr, 0, sizeof (addr)); |
| addr.sin_family = AF_INET; |
| addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK); |
| addr.sin_port = htons (NN_EFD_PORT); |
| rc = bind (listener, (const struct sockaddr*) &addr, sizeof (addr)); |
| if (nn_slow (rc == SOCKET_ERROR)) |
| goto wsafail; |
| |
| /* Start listening for the incomming connections. In normal case we are |
| going to accept just a single connection, so backlog buffer of size |
| 1 is sufficient. */ |
| rc = listen (listener, 1); |
| if (nn_slow (rc == SOCKET_ERROR)) |
| goto wsafail; |
| |
| /* The following code is in the loop, because windows sometimes delays |
| WSAEADDRINUSE error to the `connect` call. But retrying the connection |
| works like a charm. Still we want to limit number of retries */ |
| for(i = 0; i < NN_EFD_RETRIES; ++i) { |
| |
| /* Create the writer socket. */ |
| self->w = socket (AF_INET, SOCK_STREAM, 0); |
| if (nn_slow (listener == SOCKET_ERROR)) |
| goto wsafail; |
| brc = SetHandleInformation ((HANDLE) self->w, HANDLE_FLAG_INHERIT, 0); |
| win_assert (brc); |
| |
| /* Set TCP_NODELAY on the writer socket to make efd as fast as possible. |
| There's only one byte going to be written, so batching would not make |
| sense anyway. */ |
| nodelay = 1; |
| rc = setsockopt (self->w, IPPROTO_TCP, TCP_NODELAY, (char*) &nodelay, |
| sizeof (nodelay)); |
| if (nn_slow (rc == SOCKET_ERROR)) |
| goto wsafail; |
| |
| /* Connect the writer socket to the listener socket. */ |
| rc = connect (self->w, (struct sockaddr*) &addr, sizeof (addr)); |
| if (nn_slow (rc == SOCKET_ERROR)) { |
| rc = nn_err_wsa_to_posix (WSAGetLastError ()); |
| if (rc == EADDRINUSE) { |
| rc = closesocket (self->w); |
| if (nn_slow (rc == INVALID_SOCKET)) |
| goto wsafail; |
| continue; |
| } |
| goto wsafail2; |
| } |
| break; |
| } |
| if (i == NN_EFD_RETRIES) |
| goto wsafail2; |
| |
| while (1) { |
| |
| /* Accept new incoming connection. */ |
| addrlen = sizeof (addr); |
| self->r = accept (listener, (struct sockaddr*) &addr, &addrlen); |
| if (nn_slow (self->r == INVALID_SOCKET || addrlen != sizeof (addr))) |
| goto wsafail2; |
| |
| /* Check that the connection actually comes from the localhost. */ |
| if (nn_fast (addr.sin_addr.s_addr == htonl (INADDR_LOOPBACK))) |
| break; |
| |
| /* If not so, close the connection and try again. */ |
| rc = closesocket (self->r); |
| if (nn_slow (rc == INVALID_SOCKET)) |
| goto wsafail; |
| } |
| |
| /* Listener socket can be closed now as no more connections for this efd |
| are going to be established anyway. */ |
| rc = closesocket (listener); |
| if (nn_slow (rc == INVALID_SOCKET)) |
| goto wsafail; |
| |
| /* Leave the critical section. */ |
| brc = SetEvent (sync); |
| win_assert (brc != 0); |
| brc = CloseHandle (sync); |
| win_assert (brc != 0); |
| |
| /* Make the receiving socket non-blocking. */ |
| nonblock = 1; |
| rc = ioctlsocket (self->r, FIONBIO, &nonblock); |
| wsa_assert (rc != SOCKET_ERROR); |
| |
| /* Initialise the pre-allocated pollset. */ |
| FD_ZERO (&self->fds); |
| |
| return 0; |
| |
| wsafail: |
| rc = nn_err_wsa_to_posix (WSAGetLastError ()); |
| wsafail2: |
| brc = SetEvent (sync); |
| win_assert (brc != 0); |
| brc = CloseHandle (sync); |
| win_assert (brc != 0); |
| errnum_assert (0, rc); |
| return -rc; |
| } |
| |
| void nn_efd_term (struct nn_efd *self) |
| { |
| int rc; |
| |
| rc = closesocket (self->w); |
| wsa_assert (rc != INVALID_SOCKET); |
| rc = closesocket (self->r); |
| wsa_assert (rc != INVALID_SOCKET); |
| } |
| |
| nn_fd nn_efd_getfd (struct nn_efd *self) |
| { |
| return self->r; |
| } |
| |
| void nn_efd_signal (struct nn_efd *self) |
| { |
| int rc; |
| unsigned char c = 0xec; |
| |
| rc = send (self->w, (char*) &c, 1, 0); |
| wsa_assert (rc != SOCKET_ERROR); |
| nn_assert (rc == 1); |
| } |
| |
| void nn_efd_unsignal (struct nn_efd *self) |
| { |
| int rc; |
| uint8_t buf [16]; |
| |
| while (1) { |
| rc = recv (self->r, (char*) buf, sizeof (buf), 0); |
| if (rc == SOCKET_ERROR && WSAGetLastError () == WSAEWOULDBLOCK) |
| rc = 0; |
| wsa_assert (rc != SOCKET_ERROR); |
| if (nn_fast (rc < sizeof (buf))) |
| break; |
| } |
| } |
| |