// Send the two buffers and the FDs using sendmsg(), handle short writes
public unsafe void Sendmsg(byte[] buffer1, long offset1, long length1,
byte[] buffer2, long offset2, long length2,
DBus.Protocol.UnixFDArray fds)
{
//SendmsgShort (buffer1, offset1, length1, buffer2, offset2, length2, fds); return;
long bytes_overall = (long)length1 + length2;
long written = 0;
while (written < bytes_overall)
{
if (written >= length1)
{
long written2 = written - length1;
written += SendmsgShort(buffer2, offset2 + written2, length2 - written2, null, 0, 0, written == 0 ? fds : null);
}
else
{
written += SendmsgShort(buffer1, offset1 + written, length1 - written, buffer2, offset2, length2, written == 0 ? fds : null);
}
}
if (written != bytes_overall)
{
throw new Exception("written != bytes_overall");
}
}
// Send the two buffers and the FDs using sendmsg(), don't handle short writes
// length1 + length2 must not be 0
public unsafe long SendmsgShort(byte[] buffer1, long offset1, long length1,
byte[] buffer2, long offset2, long length2,
DBus.Protocol.UnixFDArray fds)
{
//Console.WriteLine ("SendmsgShort (X, {0}, {1}, {2}, {3}, {4}, {5})", offset1, length1, buffer2 == null ? "-" : "Y", offset2, length2, fds == null ? "-" : "" + fds.FDs.Count);
AssertValidBuffer(buffer1, offset1, length1);
if (buffer2 == null)
{
if (length2 != 0)
{
throw new ArgumentOutOfRangeException("length2", "!= 0 while buffer2 == null");
}
offset2 = 0;
}
else
{
AssertValidBuffer(buffer2, offset2, length2);
}
fixed(byte *ptr1 = buffer1, ptr2 = buffer2)
{
var iovecs = new Iovec[] {
new Iovec {
iov_base = (IntPtr)(ptr1 + offset1),
iov_len = (ulong)length1,
},
new Iovec {
iov_base = (IntPtr)(ptr2 + offset2),
iov_len = (ulong)length2,
},
};
/* Simulate short writes
* if (iovecs[0].iov_len == 0) {
* iovecs[1].iov_len = Math.Min (iovecs[1].iov_len, 5);
* } else {
* iovecs[0].iov_len = Math.Min (iovecs[0].iov_len, 5);
* iovecs[1].iov_len = 0;
* }
*/
byte[] cmsg = null;
// Create copy of FDs to prevent the user from Dispose()ing the
// FDs in another thread between writing the FDs into the cmsg
// buffer and calling sendmsg()
using (var fds2 = fds == null ? null : fds.Clone()) {
int fdCount = fds2 == null ? 0 : fds2.FDs.Count;
if (fdCount != 0)
{
// Create one SCM_RIGHTS control message
cmsg = new byte[Syscall.CMSG_SPACE((uint)fdCount * sizeof(int))];
}
var msghdr = new Msghdr {
msg_iov = iovecs,
msg_iovlen = length2 == 0 ? 1 : 2,
msg_control = cmsg,
msg_controllen = cmsg == null ? 0 : cmsg.Length,
};
if (fdCount != 0)
{
var hdr = new Cmsghdr {
cmsg_len = (long)Syscall.CMSG_LEN((uint)fdCount * sizeof(int)),
cmsg_level = UnixSocketProtocol.SOL_SOCKET,
cmsg_type = UnixSocketControlMessage.SCM_RIGHTS,
};
hdr.WriteToBuffer(msghdr, 0);
var dataOffset = Syscall.CMSG_DATA(msghdr, 0);
fixed(byte *ptr = cmsg)
{
for (int i = 0; i < fdCount; i++)
{
((int *)(ptr + dataOffset))[i] = fds2.FDs[i].Handle;
}
}
}
long r;
do
{
r = Syscall.sendmsg(fd, msghdr, MessageFlags.MSG_NOSIGNAL);
} while (UnixMarshal.ShouldRetrySyscall((int)r));
if (r < 0)
{
UnixMarshal.ThrowExceptionForLastError();
}
if (r == 0)
{
throw new Exception("sendmsg() returned 0");
}
return(r);
}
}
}