.include <bsd.own.mk>

LIB=		pkg-plugin-zfssnap

INCS=		zfssnap.h

#WARNS=		6

PREFIX?=	/usr/local

LIBDIR=		${PREFIX}/lib

INCLUDEDIR=	${PREFIX}/include

SHLIB_MAJOR=	0

SRCS=		zfssnap.c

CFLAGS+=	-std=c99 -fPIC -shared

CFLAGS+=	-I${INCLUDEDIR}

DEBUG_FLAGS+=  -g -O0

.include <bsd.lib.mk>

## General Information

The *pkg-plugin-zfssnap* plugin is a plugin meant to be used for creating snapshots

on a system with ZFS prior any install/deinstall actions are taken.

*pkg-plugin-zfssnap* is useful in a way that if something breaks in case your installation or

deinstallation of package(s) fails you will be able to rollback to a previously known and working

state of your system.

## How to build the plugin?

In order to build the plugin enter into the plugin's directory and run make(1), e.g.:

	$ cd /path/to/pkg-plugins-zfssnap

	$ make

Once the plugin is built you can install it using the following command:

	$ make install 

The plugin will be installed as a shared library in ${PREFIX}/lib/libpkg-plugin-zfssnap.so

## Configuring the plugin

In order to configure the plugin simply copy the *zfssnap.conf* file to the pkgng plugins directory,

which by default is set to */usr/local/etc/pkg/plugins*, unless you've specified it elsewhere by 

using the *PKG\_PLUGINS\_DIR* option.

	$ cp /path/to/pkg-plugins-zfssnap/zfssnap.conf /usr/local/etc/pkg/plugins/

Next, open */usr/local/etc/pkg/plugins/zfssnap.conf* and configure any ZFS related options.

## Testing the plugin

To test the plugin, first check that it is recognized and

loaded by pkgng by executing the `pkg plugins` command:

	$ pkg plugins

	NAME       DESC                                VERSION    LOADED    

	zfssnap    ZFS snapshot plugin for pkgng       1.0        YES       

If the plugin shows up correctly then you are good to go! :)

Once you start installing/deinstall package(s) zfssnap will create a snapshot for you! 

/*

 * Copyright (c) 2012 Marin Atanasov Nikolov <dnaeon@gmail.com>

 * All rights reserved.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer

 *    in this position and unchanged.

 * 2. 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.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 THE AUTHOR(S) 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.

 */

#include <sys/types.h>

#include <sys/param.h>

#include <assert.h>

#include <fcntl.h>

#include <time.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdbool.h>

#include <string.h>

#include <libutil.h>

#include <unistd.h>

#include <pkg.h>

#include "zfssnap.h"

#define PLUGIN_NAME "zfssnap"

#define PLUGIN_CONF "/usr/local/etc/pkg/plugins/zfssnap.conf"

static struct _zfssnap_config {

        const char *key;

        const char *val;

} c[] = {

        { "zfs_fs", NULL },

	{ "zfs_prefix", NULL },

        { "zfs_args", NULL },

        { NULL, NULL }

};

static int plugins_zfssnap_load_conf(const char *file);

static const char *plugins_zfssnap_get_conf(const char *key);

static int plugins_zfssnap_fd = -1;

static properties plugins_zfssnap_p = NULL;

int

pkg_plugins_init_zfssnap(void)

{

	if (plugins_zfssnap_load_conf(PLUGIN_CONF) != EPKG_OK) {

		fprintf(stderr, ">>> Cannot parse configuration file %s\n", PLUGIN_CONF);

		return (EPKG_FATAL);

	}

	if (pkg_plugins_hook(PLUGIN_NAME, PKG_PLUGINS_HOOK_PRE_INSTALL, &plugins_zfssnap_callback) != EPKG_OK) {

		fprintf(stderr, ">>> Plugin '%s' failed to hook into the library\n", PLUGIN_NAME);

		return (EPKG_FATAL);

	}

	if (pkg_plugins_hook(PLUGIN_NAME, PKG_PLUGINS_HOOK_PRE_DEINSTALL, &plugins_zfssnap_callback) != EPKG_OK) {

		fprintf(stderr, ">>> Plugin '%s' failed to hook into the library\n", PLUGIN_NAME);

		return (EPKG_FATAL);

	}

	return (EPKG_OK);

}

int

pkg_plugins_shutdown_zfssnap(void)

{

	properties_free(plugins_zfssnap_p);

	close(plugins_zfssnap_fd);

	return (EPKG_OK);

}

static int

plugins_zfssnap_load_conf(const char *file)

{

        int i;

	bool wrong_conf = false;

	assert(file != NULL);

	if ((plugins_zfssnap_fd = open(file, O_RDONLY)) < 0) {

                fprintf(stderr, ">>> Cannot open configuration file %s", file);

                return (EPKG_FATAL);

        }

	plugins_zfssnap_p = properties_read(plugins_zfssnap_fd);

        for (i = 0; c[i].key != NULL; i++)

		c[i].val = property_find(plugins_zfssnap_p, c[i].key);

	return (EPKG_OK);

}

static const char *

plugins_zfssnap_get_conf(const char *key)

{

	unsigned int i;

	assert (key != NULL);

        for (i = 0; c[i].key != NULL; i++)

		if (strcmp(c[i].key, key) == 0)

			return (c[i].val);

	return (NULL);

}

int

plugins_zfssnap_callback(void *data, struct pkgdb *db)

{

	char cmd_buf[MAXPATHLEN + 1];

	struct tm *tm = NULL;

	const char *zfs_fs = NULL;

	const char *zfs_args = NULL;

	const char *zfs_prefix = NULL;

	time_t t = 0;

	t = time(NULL);

	tm = localtime(&t);

	/* we don't care about data and db, so nothing to assert() here */

	/* assert(db != NULL); */ 

	/* assert(data != NULL); */

	zfs_fs = plugins_zfssnap_get_conf("zfs_fs");

	zfs_args = plugins_zfssnap_get_conf("zfs_args");

	zfs_prefix = plugins_zfssnap_get_conf("zfs_prefix");

	if ((zfs_fs == NULL) || (zfs_prefix == NULL)) {

		fprintf(stderr, ">>> Configuration options missing, plugin '%s' will not be loaded\n",

			       PLUGIN_NAME);

		return (EPKG_FATAL);

	}

	snprintf(cmd_buf, sizeof(cmd_buf), "%s %s %s@%s-%d-%d-%d_%d.%d.%d",

		 "/sbin/zfs snapshot", zfs_args,

		 zfs_fs, zfs_prefix,

		 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,

		 tm->tm_hour, tm->tm_min, tm->tm_sec);

	printf(">>> Creating ZFS snapshot\n");

	system(cmd_buf);

	return (EPKG_OK);

}

# Configuration file for pkg-plugin-template

enabled=YES

name=zfssnap

description=ZFS snapshot plugin for pkgng

version=1.0

plugin=/usr/local/lib/libpkg-plugin-zfssnap.so

#

# zfssnap specific options follow below

#

# ZFS file system

zfs_fs=zroot

# ZFS args, '-r' for recursive snapshots creation

zfs_args=-r

# ZFS snapshot prefix name

zfs_prefix=zfssnap

/*

 * Copyright (c) 2012 Marin Atanasov Nikolov <dnaeon@gmail.com>

 * All rights reserved.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer

 *    in this position and unchanged.

 * 2. 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.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 THE AUTHOR(S) 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.

 */

#ifndef _PKG_PLUGINS_ZFSSNAP_H

#define _PKG_PLUGINS_ZFSSNAP_H

/* callback functions */

int plugins_zfssnap_callback(void *data, struct pkgdb *db);

/* plugin init and shutdown functions */

int pkg_plugins_init_zfssnap(void);

int pkg_plugins_shutdown_zfssnap(void);

#endif /* !_PKG_PLUGINS_ZFSSNAP_H */