nbd_set_tcp_option - Man Page

 #include <libnbd.h>

 int nbd_set_tcp_option (
       struct nbd_handle *h, int option, int v
     );

If making a TCP connection then you can call this function to set a subset of TCP options on the socket.

Currently the option parameter may be one of:

• TCP_KEEPCNT
• TCP_KEEPIDLE
• TCP_KEEPINTVL

These options may not work on non-Linux systems.

For the TCP_KEEP* options, keepalive must also be enabled by calling nbd_set_keepalive(3)).

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_set_tcp_option 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 1.26.

If you need to test if this function is available at compile time check if the following macro is defined:

 #define LIBNBD_HAVE_NBD_SET_TCP_OPTION 1

nbd_create(3), nbd_set_keepalive(3), libnbd(3), setsockopt(2), tcp(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.

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

libnbd(3), NBD(3), nbd_set_keepalive(3).