1nbd_get_protocol(3) LIBNBD nbd_get_protocol(3)
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6 nbd_get_protocol - return the NBD protocol variant
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9 #include <libnbd.h>
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11 const char * nbd_get_protocol (struct nbd_handle *h);
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14 Return the NBD protocol variant in use on the connection. At the
15 moment this returns one of the strings "oldstyle", "newstyle" or
16 "newstyle-fixed". Other strings might be returned in the future. Most
17 modern NBD servers use "newstyle-fixed".
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19 This call does not block, because it returns data that is saved in the
20 handle from the NBD protocol handshake.
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23 This call returns a statically allocated string, valid for the lifetime
24 of the process or until libnbd is unloaded by dlclose(3). You must not
25 try to free the string.
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28 On error "NULL" is returned.
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30 Refer to "ERROR HANDLING" in libnbd(3) for how to get further details
31 of the error.
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34 The handle must be negotiating, or connected with the server, or shut
35 down, otherwise this call will return an error.
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38 This function first appeared in libnbd 1.2.
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40 If you need to test if this function is available at compile time check
41 if the following macro is defined:
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43 #define LIBNBD_HAVE_NBD_GET_PROTOCOL 1
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46 nbd_create(3), nbd_get_block_size(3), nbd_get_handshake_flags(3),
47 nbd_get_structured_replies_negotiated(3), nbd_get_tls_negotiated(3),
48 libnbd(3).
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51 Eric Blake
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53 Richard W.M. Jones
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56 Copyright (C) 2019-2021 Red Hat Inc.
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59 This library is free software; you can redistribute it and/or modify it
60 under the terms of the GNU Lesser General Public License as published
61 by the Free Software Foundation; either version 2 of the License, or
62 (at your option) any later version.
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64 This library is distributed in the hope that it will be useful, but
65 WITHOUT ANY WARRANTY; without even the implied warranty of
66 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
67 Lesser General Public License for more details.
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69 You should have received a copy of the GNU Lesser General Public
70 License along with this library; if not, write to the Free Software
71 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
72 02110-1301 USA
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76libnbd-1.7.12 2021-05-29 nbd_get_protocol(3)