nbd_connect_tcp(3) LIBNBD nbd_connect_tcp(3)

nbd_connect_tcp - connect to NBD server over a TCP port

#include <libnbd.h>
int nbd_connect_tcp (
      struct nbd_handle *h, const char *hostname,
      const char *port
    );

Connect (synchronously) to the NBD server listening on "hostname:port". The "port" may be a port name such as "nbd", or it may be a port number as a string such as "10809".

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", "hostname", "port". For more information see "Non-NULL parameters" in libnbd(3).

nbd_connect_tcp 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 1.0.

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_TCP 1

nbd_aio_connect_tcp(3), nbd_create(3), nbd_set_opt_mode(3), libnbd(3).

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.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

2024-05-31 libnbd-1.20.0