Handle pipes on platforms where they are non-existant of broken.

We do this by creating a TCP socket pair instead of a normal pipe. Since
Windows isn't UNIX-y enough to support read()/write() on sockets, we also
need a wrapper to handle read() vs recv() and write() vs send().


git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@840 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/polypcore/pipe.c

@@ -0,0 +1,160 @@
+/* $Id$ */
+
+/***
+   This file is part of polypaudio.
+
+   polypaudio is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Library General Public License as published
+   by the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   polypaudio is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with polypaudio; If not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+   USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <sys/types.h>
+
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+
+#include "winsock.h"
+
+#include "pipe.h"
+
+#ifndef HAVE_PIPE
+
+static int set_block(int fd, int blocking) {
+#ifdef O_NONBLOCK
+
+    int v;
+
+    assert(fd >= 0);
+
+    if ((v = fcntl(fd, F_GETFL)) < 0)
+        return -1;
+
+    if (blocking)
+        v &= ~O_NONBLOCK;
+    else
+        v |= O_NONBLOCK;
+
+    if (fcntl(fd, F_SETFL, v) < 0)
+        return -1;
+
+    return 0;
+
+#elif defined(OS_IS_WIN32)
+
+    u_long arg;
+
+    arg = !blocking;
+
+    if (ioctlsocket(fd, FIONBIO, &arg) < 0)
+        return -1;
+
+    return 0;
+
+#else
+
+    return -1;
+
+#endif
+}
+
+int pipe(int filedes[2]) {
+    int listener;
+    struct sockaddr_in addr, peer;
+    socklen_t len;
+
+    listener = -1;
+    filedes[0] = -1;
+    filedes[1] = -1;
+
+    listener = socket(PF_INET, SOCK_STREAM, 0);
+    if (listener < 0)
+        goto error;
+
+    filedes[0] = socket(PF_INET, SOCK_STREAM, 0);
+    if (filedes[0] < 0)
+        goto error;
+
+    filedes[1] = socket(PF_INET, SOCK_STREAM, 0);
+    if (filedes[1] < 0)
+        goto error;
+
+    /* Make non-blocking so that connect() won't block */
+    if (set_block(filedes[0], 0) < 0)
+        goto error;
+
+    addr.sin_family = AF_INET;
+    addr.sin_port = 0;
+    addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+    if (bind(listener, (struct sockaddr*)&addr, sizeof(addr)) < 0)
+        goto error;
+
+    if (listen(listener, 1) < 0)
+        goto error;
+
+    len = sizeof(addr);
+    if (getsockname(listener, (struct sockaddr*)&addr, &len) < 0)
+        goto error;
+
+    if (connect(filedes[0], (struct sockaddr*)&addr, sizeof(addr)) < 0) {
+#ifdef OS_IS_WIN32
+        if (WSAGetLastError() != EWOULDBLOCK)
+#else
+        if (errno != EINPROGRESS)
+#endif
+            goto error;
+    }
+
+    len = sizeof(peer);
+    filedes[1] = accept(listener, (struct sockaddr*)&peer, &len);
+    if (filedes[1] < 0)
+        goto error;
+
+    /* Restore blocking */
+    if (set_block(filedes[0], 1) < 0)
+        goto error;
+
+    len = sizeof(addr);
+    if (getsockname(filedes[0], (struct sockaddr*)&addr, &len) < 0)
+        goto error;
+
+    /* Check that someone else didn't steal the connection */
+    if ((addr.sin_port != peer.sin_port) || (addr.sin_addr.s_addr != peer.sin_addr.s_addr))
+        goto error;
+
+    close(listener);
+
+    return 0;
+
+error:
+	if (listener >= 0)
+		close(listener);
+	if (filedes[0] >= 0)
+		close(filedes[0]);
+	if (filedes[1] >= 0)
+		close(filedes[0]);
+
+	return -1;
+}
+
+#endif /* HAVE_PIPE */