+ssize_t sendmsg(int sockfd, const struct msghdr *msg, int flags)
+{
+ LPFN_WSASENDMSG WSASendMsg = NULL;
+ GUID wsaid = WSAID_WSASENDMSG;
+ DWORD b;
+
+ DWORD bytessent;
+ WSAMSG wsamsg;
+ size_t i;
+ int r;
+
+ // size_t is larger than DWORD on 64bit
+ if(msg->msg_iovlen > UINT32_MAX) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ // obtain the function pointer to WSASendMsg
+ r = WSAIoctl(sockfd, SIO_GET_EXTENSION_FUNCTION_POINTER,
+ &wsaid, sizeof(wsaid), &WSASendMsg, sizeof(WSASendMsg),
+ &b, NULL, NULL);
+ if(r == SOCKET_ERROR) {
+ errno = wsa_errno();
+ return -1;
+ }
+ assert(b == sizeof(WSASendMsg));
+ assert(WSASendMsg != NULL);
+
+ // convert msghdr to WSAMSG structure
+ wsamsg.name = msg->msg_name;
+ wsamsg.namelen = msg->msg_namelen;
+ wsamsg.lpBuffers = malloc(msg->msg_iovlen * sizeof(WSABUF));
+ wsamsg.dwBufferCount = msg->msg_iovlen;
+ wsamsg.Control.len = msg->msg_controllen;
+ wsamsg.Control.buf = msg->msg_control;
+ wsamsg.dwFlags = 0; // ignored
+
+ if(wsamsg.lpBuffers == NULL) {
+ // malloc will have set errno
+ return -1;
+ }
+
+ // re-wrap iovecs as WSABUFs
+ for(i=0; i<msg->msg_iovlen; i++) {
+ // size_t vs. u_long
+ if(msg->msg_iov[i].iov_len > ULONG_MAX) {
+ free(wsamsg.lpBuffers);
+ errno = EINVAL;
+ return -1;
+ }
+
+ wsamsg.lpBuffers[i].len = msg->msg_iov[i].iov_len;
+ wsamsg.lpBuffers[i].buf = msg->msg_iov[i].iov_base;
+ }
+
+ r = WSASendMsg(sockfd, &wsamsg, flags, &bytessent, NULL, NULL);
+
+ // the allocated WSABUF wrappers are no longer needed
+ free(wsamsg.lpBuffers);
+
+ if(r == SOCKET_ERROR) {
+ // XXX do we need special handling for ENETRESET, ETIMEDOUT?
+ errno = wsa_errno();
+ return -1;
+ }
+
+ // DWORD has one bit more than ssize_t on 32bit
+ // XXX check for this condition before sending anything
+ if(bytessent > SSIZE_MAX) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ return bytessent;
+}
+
+int ioctl(int d, unsigned long request, int *p)
+{
+ u_long arg = *p;
+
+ if(ioctlsocket(d, request, &arg) == SOCKET_ERROR) {
+ errno = wsa_errno();
+ return -1;
+ }
+
+ if(arg > INT_MAX) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ *p = arg;
+ return 0;
+}
+
+int pipe(int pipefd[2])
+{
+ int lsock = (int)INVALID_SOCKET;
+ struct sockaddr_in laddr;
+ socklen_t laddrlen = sizeof(laddr);
+
+ pipefd[0] = pipefd[1] = (int)INVALID_SOCKET;
+
+ // bind a listening socket to a TCP port on localhost
+ laddr.sin_family = AF_INET;
+ laddr.sin_port = 0;
+ laddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ if((lsock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == SOCKET_ERROR)
+ goto fail;
+ if(bind(lsock, (struct sockaddr *)&laddr, sizeof(laddr)) == SOCKET_ERROR)
+ goto fail;
+ if(listen(lsock, 1) == SOCKET_ERROR)
+ goto fail;
+
+ // determine which address (i.e. port) we got bound to
+ if(getsockname(lsock, (struct sockaddr *)&laddr, &laddrlen) == SOCKET_ERROR)
+ goto fail;
+ assert(laddrlen == sizeof(laddr));
+ laddr.sin_family = AF_INET;
+ laddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+ // connect and accept
+ if((pipefd[0] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == SOCKET_ERROR)
+ goto fail;
+ if(connect(pipefd[0], (const struct sockaddr *)&laddr, sizeof(laddr)) == SOCKET_ERROR)
+ goto fail;
+ if((pipefd[1] = accept(lsock, NULL, NULL)) == SOCKET_ERROR)
+ goto fail;
+
+ // close the listener
+ closesocket(lsock);
+
+ return 0;
+
+fail:
+ errno = wsa_errno();
+ closesocket(pipefd[0]);
+ closesocket(lsock);
+ return -1;
+}
+