nbd_connect_vsock - connect to NBD server over AF_VSOCK protocol
#include <libnbd.h>
int nbd_connect_vsock (
struct nbd_handle *h, uint32_t cid, uint32_t port
);Connect (synchronously) over the AF_VSOCK protocol from a virtual machine to an NBD server, usually running on the host. The cid and port parameters specify the server address. Usually cid should be 2 (to connect to the host), and port might be 10809 or another port number assigned to you by the host administrator.
Not all systems support AF_VSOCK; to determine if libnbd was built on a system with vsock support, see nbd_supports_vsock(3).
This call returns when the connection has been made. By default, this proceeds all the way to transmission phase, but nbd_set_opt_mode(3) can be used for manual control over option negotiation performed before transmission phase.
If the call is successful the function returns 0.
On error -1 is returned.
Refer to "ERROR HANDLING" in libnbd(3) for how to get further details of the error.
The following parameters must not be NULL: h. For more information see "Non-NULL parameters" in libnbd(3).
nbd_connect_vsock can be called when the handle is in the following state:
┌─────────────────────────────────────┬─────────────────────────┐
│ Handle created, before connecting │ ✅ allowed │
│ Connecting │ ❌ error │
│ Connecting & handshaking (opt_mode) │ ❌ error │
│ Connected to the server │ ❌ error │
│ Connection shut down │ ❌ error │
│ Handle dead │ ❌ error │
└─────────────────────────────────────┴─────────────────────────┘This function first appeared in libnbd 1.2.
If you need to test if this function is available at compile time check if the following macro is defined:
#define LIBNBD_HAVE_NBD_CONNECT_VSOCK 1nbd_aio_connect_vsock(3), nbd_create(3), nbd_set_opt_mode(3), nbd_supports_vsock(3), libnbd(3), vsock(7).
Eric Blake
Richard W.M. Jones
Copyright Red Hat
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This library 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 Lesser General Public License for more details.
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