/*
 * 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/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 {
        int     gp_fd;
        int     monitor_fd;
        int     refs;

        void    *userdata;
};

struct udev *
udev_ref(struct udev *udev_ctx)
{
        atomic_add_int(&udev_ctx->refs, 1);

        return udev_ctx;
}

void
udev_unref(struct udev *udev_ctx)
{
        int refcount;

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

        if (refcount == 1) {
                atomic_subtract_int(&udev_ctx->refs, 0x400); /* in destruction */
                if (udev_ctx->gp_fd != -1)
                        close (udev_ctx->gp_fd);
                if (udev_ctx->monitor_fd != -1)
                        close (udev_ctx->monitor_fd);

                free(udev_ctx);
        }
}

struct udev *
udev_new(void)
{
        struct udev *udev_ctx;
        int ret, s;

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

        udev_ctx = malloc(sizeof(struct udev));

        udev_ctx->refs = 1;
        udev_ctx->gp_fd = s;
        udev_ctx->monitor_fd = -1;
        udev_ctx->userdata = NULL;

        return udev_ctx;
}

const char *udev_get_dev_path(struct udev *udev_ctx __unused)
{
        return "/dev";
}

void *
udev_get_userdata(struct udev *udev_ctx)
{
        return udev_ctx->userdata;
}

void
udev_set_userdata(struct udev *udev_ctx, void *userdata)
{
        udev_ctx->userdata = userdata;
}

int
udev_get_fd(struct udev *udev_ctx)
{
        return udev_ctx->gp_fd;
}

int
send_xml(int s, char *xml)
{
        ssize_t r,n;
        size_t sz;

        sz = strlen(xml) + 1;

        r = send(s, &sz, sizeof(sz), 0);
        if (r <= 0)
                return r;

        r = 0;
        while (r < (ssize_t)sz) {
                n = send(s, xml+r, sz-r, 0);
                if (n <= 0)
                        return n;
                r += n;
        }

        return r;
}

int
read_xml(int s, char **buf)
{
        char *xml;
        size_t sz;
        int n, r;

        *buf = NULL;

        n = recv(s, &sz, sizeof(sz), MSG_WAITALL);
        if ((n <= 0) || (sz > 12*1024*1024)) /* Arbitrary limit */
                return n;

        xml = malloc(sz+2);
        r = 0;
        while (r < (ssize_t)sz) {
                n = recv(s, xml+r, sz-r, MSG_WAITALL);
                if (n <= 0) {
                        free(xml);
                        return n;
                }
                r += n;
        }

        *buf = xml;
        return r;
}

int
_udev_dict_set_cstr(prop_dictionary_t dict, const char *key, char *str)
{
        prop_string_t   ps;

        ps = prop_string_create_cstring(str);
        if (ps == NULL)
                return ENOMEM;

        if (prop_dictionary_set(dict, key, ps) == false) {
                prop_object_release(ps);
                return ENOMEM;
        }

        prop_object_release(ps);
        return 0;
}

int
_udev_dict_set_int(prop_dictionary_t dict, const char *key, int64_t val)
{
        prop_number_t   pn;

        pn = prop_number_create_integer(val);
        if (pn == NULL)
                return ENOMEM;

        if (prop_dictionary_set(dict, key, pn) == false) {
                prop_object_release(pn);
                return ENOMEM;
        }

        prop_object_release(pn);
        return 0;
}

int
_udev_dict_set_uint(prop_dictionary_t dict, const char *key, uint64_t val)
{
        prop_number_t   pn;

        pn = prop_number_create_unsigned_integer(val);
        if (pn == NULL)
                return ENOMEM;

        if (prop_dictionary_set(dict, key, pn) == false) {
                prop_object_release(pn);
                return ENOMEM;
        }

        prop_object_release(pn);
        return 0;
}

int
conn_local_server(const char *sockfile, int socktype, int nonblock __unused,
                  int *retsock)
{
        int s;
        struct sockaddr_un serv_addr;

        *retsock = -1;
        if ((s = socket(AF_UNIX, socktype, 0)) < 0)
                return -1;

        memset(&serv_addr, 0, sizeof(serv_addr));
        serv_addr.sun_family = AF_UNIX;
        strncpy(serv_addr.sun_path, sockfile, SOCKFILE_NAMELEN);
        serv_addr.sun_path[SOCKFILE_NAMELEN - 1] = '\0';

        *retsock = s;
        return connect(s, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
}

prop_dictionary_t
udevd_get_command_dict(char *command)
{
        prop_dictionary_t       dict;
        int     error;

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

        if ((error = _udev_dict_set_cstr(dict, "command", command)))
                goto error_out;

        return dict;

error_out:
        prop_object_release(dict);
        return NULL;
}

prop_array_t
udevd_request_devs(int s, prop_array_t filters)
{
        prop_array_t    pa;
        prop_dictionary_t       dict;
        char *xml;

        int n;

        dict = udevd_get_command_dict(__DECONST(char *, "getdevs"));
        if (dict == NULL)
                return NULL;

        /* Add filters to message, if available */
        if (filters != NULL) {
                if (prop_dictionary_set(dict, "filters", filters) == false) {
                        prop_object_release(dict);
                        return NULL;
                }
        }

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

        n = send_xml(s, xml);
        free(xml);

        if (n <= 0)
                return NULL;

        if ((n = read_xml(s, &xml)) <= 0)
                return NULL;

        xml[n+1] = '\0';
        pa = prop_array_internalize(xml);
        free(xml);
        return (pa);
}