/*
 * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Alex Hornung <ahornung@gmail.com>
 *
 * 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.
 * 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.
 * 3. Neither the name of The DragonFly Project 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 THE COPYRIGHT HOLDERS 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 THE
 * COPYRIGHT HOLDERS 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.
 */
#include <sys/types.h>
#include <sys/device.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/queue.h>
#include <sys/un.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <regex.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include <libprop/proplib.h>
#include <sys/udev.h>
#define LIBDEVATTR_INTERNAL
#include "devattr.h"

struct udev_monitor {
        struct udev     *udev_ctx;
        prop_array_t    ev_filt;
        int     socket;
        int     user_socket; /* maybe... one day... */
        int     refs;
};

struct udev_monitor *
udev_monitor_new(struct udev *udev_ctx)
{
        struct udev_monitor *udev_monitor;
        int ret, s;

        ret = conn_local_server(LISTEN_SOCKET_FILE, SOCK_STREAM, 0, &s);
        if (ret < 0)
                return NULL;

        udev_monitor = malloc(sizeof(struct udev_monitor));
        if (udev_monitor == NULL)
                return NULL;

        udev_monitor->refs = 1;
        udev_monitor->ev_filt = NULL;
        udev_monitor->socket = s;
        udev_monitor->user_socket = 1;
        udev_monitor->udev_ctx = udev_ref(udev_ctx);

        return udev_monitor;
}


struct udev_monitor *
udev_monitor_ref(struct udev_monitor *udev_monitor)
{
        atomic_add_int(&udev_monitor->refs, 1);

        return udev_monitor;
}

void
udev_monitor_unref(struct udev_monitor *udev_monitor)
{
        int refcount;

        refcount = atomic_fetchadd_int(&udev_monitor->refs, -1);

        if (refcount == 1) {
                atomic_subtract_int(&udev_monitor->refs, 0x400); /* in destruction */
                if (udev_monitor->ev_filt != NULL)
                        prop_object_release(udev_monitor->ev_filt);

                if (udev_monitor->socket != -1)
                        close(udev_monitor->socket);
                if (udev_monitor->user_socket != -1)
                        close(udev_monitor->user_socket);

                udev_unref(udev_monitor->udev_ctx);
                free(udev_monitor);
        }
}

struct udev *
udev_monitor_get_udev(struct udev_monitor *udev_monitor)
{
        return udev_monitor->udev_ctx;
}

int
udev_monitor_get_fd(struct udev_monitor *udev_monitor)
{
        return udev_monitor->socket;
}

struct udev_device *
udev_monitor_receive_device(struct udev_monitor *udev_monitor)
{
        struct udev_device *udev_dev;
        prop_dictionary_t dict, evdict;
        prop_number_t   pn;
        char *xml;
        int n;

        if ((n = read_xml(udev_monitor->socket, &xml)) <= 0)
                return NULL;

        xml[n+1] = '\0';
        dict = prop_dictionary_internalize(xml);
        free(xml);
        if (dict == NULL)
                return NULL;

        pn = prop_dictionary_get(dict, "evtype");
        if (pn == NULL) {
                prop_object_release(dict);
                return NULL;
        }

        evdict = prop_dictionary_get(dict, "evdict");
        if (evdict == NULL) {
                prop_object_release(dict);
                return NULL;
        }

        udev_dev = udev_device_new_from_dictionary(udev_monitor->udev_ctx, evdict);
        if (udev_dev == NULL) {
                prop_object_release(dict);
                return NULL;
        }

        udev_device_set_action(udev_dev, prop_number_integer_value(pn));

        prop_object_release(dict);
        return udev_dev;
}

int
udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
{
        prop_dictionary_t       dict;
        char *xml;
        int n;
        /* ->socket, ->user_socket, ->ev_filt */

        dict = udevd_get_command_dict(__DECONST(char *, "monitor"));
        if (dict == NULL)
                return -1;

        /* Add event filters to message, if available */
        if (udev_monitor->ev_filt != NULL) {
                if (prop_dictionary_set(dict, "filters",
                    udev_monitor->ev_filt) == false) {
                        prop_object_release(dict);
                        return -1;
                }
        }

        xml = prop_dictionary_externalize(dict);
        prop_object_release(dict);
        if (xml == NULL)
                return -1;

        n = send_xml(udev_monitor->socket, xml);
        free(xml);
        if (n <= 0)
                return -1;

        return 0;
}

int
udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor,
                                                const char *subsystem,
                                                const char *devtype __unused)
{
        int ret;

        ret = _udev_monitor_filter_add_match_gen(udev_monitor,
                                                 EVENT_FILTER_TYPE_WILDCARD,
                                                 0,
                                                 "subsystem",
                                                 __DECONST(char *, subsystem));

        return ret;
}

int
udev_monitor_filter_add_match_expr(struct udev_monitor *udev_monitor,
                                   const char *key,
                                   char *expr)
{
        int ret;

        ret = _udev_monitor_filter_add_match_gen(udev_monitor,
                                                 EVENT_FILTER_TYPE_WILDCARD,
                                                 0,
                                                 key,
                                                 expr);

        return ret;
}

int
udev_monitor_filter_add_nomatch_expr(struct udev_monitor *udev_monitor,
                                     const char *key,
                                     char *expr)
{
        int ret;

        ret = _udev_monitor_filter_add_match_gen(udev_monitor,
                                                 EVENT_FILTER_TYPE_WILDCARD,
                                                 1,
                                                 key,
                                                 expr);

        return ret;
}

int
udev_monitor_filter_add_match_regex(struct udev_monitor *udev_monitor,
                                   const char *key,
                                   char *expr)
{
        int ret;

        ret = _udev_monitor_filter_add_match_gen(udev_monitor,
                                                 EVENT_FILTER_TYPE_REGEX,
                                                 0,
                                                 key,
                                                 expr);

        return ret;
}

int
udev_monitor_filter_add_nomatch_regex(struct udev_monitor *udev_monitor,
                                     const char *key,
                                     char *expr)
{
        int ret;

        ret = _udev_monitor_filter_add_match_gen(udev_monitor,
                                                 EVENT_FILTER_TYPE_REGEX,
                                                 1,
                                                 key,
                                                 expr);

        return ret;
}

int
_udev_filter_add_match_gen(prop_array_t filters,
                                   int type,
                                   int neg,
                                   const char *key,
                                   char *expr)
{
        prop_dictionary_t       dict;
        int error;

        if (key == NULL)
                return -1;
        if (expr == NULL)
                return -1;

        dict = prop_dictionary_create();
        if (dict == NULL)
                return -1;

        error = _udev_dict_set_cstr(dict, "key", __DECONST(char *, key));
        if (error != 0)
                goto error_out;
        error = _udev_dict_set_int(dict, "type", type);
        if (error != 0)
                goto error_out;
        error = _udev_dict_set_cstr(dict, "expr", expr);
        if (error != 0)
                goto error_out;

        if (neg) {
                error = _udev_dict_set_int(dict, "negative", 1);
                if (error != 0)
                        goto error_out;
        }

        if (prop_array_add(filters, dict) == false)
                goto error_out;

        return 0;

error_out:
        prop_object_release(dict);
        return -1;
}

int
_udev_monitor_filter_add_match_gen(struct udev_monitor *udev_monitor,
                                   int type,
                                   int neg,
                                   const char *key,
                                   char *expr)
{
        prop_array_t            pa;
        int error;

        if (udev_monitor->ev_filt == NULL) {
                pa = prop_array_create_with_capacity(5);
                if (pa == NULL)
                        return -1;

                udev_monitor->ev_filt = pa;
        }

        error = _udev_filter_add_match_gen(udev_monitor->ev_filt, type, neg, key, expr);

        return error;
}