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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* Both nbdkit-sh-plugin and nbdkit-eval-plugin are implemented using
* common code from plugin/sh/. These "sub-plugins" are abstracted
* through the 'struct subplugin' interface. There is one global
* instance of this struct (per plugin), called 'sub'.
*/
#ifndef NBDKIT_SUBPLUGIN_H
#define NBDKIT_SUBPLUGIN_H
#include "nbdkit-string.h"
/* Exit codes. */
typedef enum exit_code {
OK = 0,
ERROR = 1, /* all script error codes are mapped to this */
MISSING = 2, /* method missing */
RET_FALSE = 3, /* script exited with code 3 meaning false */
SHUTDOWN_OK = 4, /* call nbdkit_shutdown(), then return OK */
SHUTDOWN_ERR = 5, /* call nbdkit_shutdown(), then return ERROR */
DISC_FORCE = 6, /* call nbdkit_disconnect(true); return is irrelevant */
DISC_SOFT_OK = 7, /* call nbdkit_disconnect(false), return OK */
DISC_SOFT_ERR = 8, /* call nbdkit_disconnect(false), return ERROR */
/* Adjust methods.c:sh_dump_plugin when defining new codes */
/* 9-15 are reserved since 1.34; handle like ERROR for now */
} exit_code;
struct subplugin {
/* Common methods in plugin/sh/methods.c use get_script to
* initialize argv[0] before calling the call* functions below.
*
* From sh_dump_plugin and sh_thread_model ONLY it is possible for
* this function to return NULL. From all other contexts it must
* return a script name.
*/
const char *(*get_script) (const char *method);
/* How to call most methods which require only a list of args.
* argv[0] is the script filename. argv[1] is the method name.
*/
exit_code (*call) (const char **argv)
__attribute__ ((__nonnull__ (1)));
/* For methods which return a string. Note that rbuf should be a
* variable initialized to empty_vector. On success it is allocated
* by this function.
*/
exit_code (*call_read) (string *rbuf, const char **argv)
__attribute__ ((__nonnull__ (1, 2)));
/* For methods which take an input buffer. Only pwrite uses this. */
exit_code (*call_write) (const char *wbuf, size_t wbuflen,
const char **argv)
__attribute__ ((__nonnull__ (1, 3)));
};
extern struct subplugin sub;
#endif /* NBDKIT_SUBPLUGIN_H */
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