/*
 *      ucon.c
 *
 * Copyright (c) 2004+ Evgeniy Polyakov <johnpol@2ka.mipt.ru>
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <asm/types.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/poll.h>

#include <linux/netlink.h>
#include <linux/rtnetlink.h>

#include <arpa/inet.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <time.h>

#include <linux/connector.h>

#define DEBUG
#define NETLINK_CONNECTOR       11

#ifdef DEBUG
#define ulog(f, a...) fprintf(stdout, f, ##a)
#else
#define ulog(f, a...) do {} while (0)
#endif

static int need_exit;
static __u32 seq;

static int netlink_send(int s, struct cn_msg *msg)
{
        struct nlmsghdr *nlh;
        unsigned int size;
        int err;
        char buf[128];
        struct cn_msg *m;

        size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);

        nlh = (struct nlmsghdr *)buf;
        nlh->nlmsg_seq = seq++;
        nlh->nlmsg_pid = getpid();
        nlh->nlmsg_type = NLMSG_DONE;
        nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
        nlh->nlmsg_flags = 0;

        m = NLMSG_DATA(nlh);
#if 0
        ulog("%s: [%08x.%08x] len=%u, seq=%u, ack=%u.\n",
               __func__, msg->id.idx, msg->id.val, msg->len, msg->seq, msg->ack);
#endif
        memcpy(m, msg, sizeof(*m) + msg->len);

        err = send(s, nlh, size, 0);
        if (err == -1)
                ulog("Failed to send: %s [%d].\n",
                        strerror(errno), errno);

        return err;
}

int main(int argc, char *argv[])
{
        int s;
        char buf[1024];
        int len;
        struct nlmsghdr *reply;
        struct sockaddr_nl l_local;
        struct cn_msg *data;
        FILE *out;
        time_t tm;
        struct pollfd pfd;

        if (argc < 2)
                out = stdout;
        else {
                out = fopen(argv[1], "a+");
                if (!out) {
                        ulog("Unable to open %s for writing: %s\n",
                                argv[1], strerror(errno));
                        out = stdout;
                }
        }

        memset(buf, 0, sizeof(buf));

        s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
        if (s == -1) {
                perror("socket");
                return -1;
        }

        l_local.nl_family = AF_NETLINK;
        l_local.nl_groups = 0x123; /* bitmask of requested groups */
        l_local.nl_pid = 0;

        if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
                perror("bind");
                close(s);
                return -1;
        }

#if 0
        {
                int on = 0x57; /* Additional group number */
                setsockopt(s, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &on, sizeof(on));
        }
#endif
        if (0) {
                int i, j;

                memset(buf, 0, sizeof(buf));

                data = (struct cn_msg *)buf;

                data->id.idx = 0x123;
                data->id.val = 0x456;
                data->seq = seq++;
                data->ack = 0;
                data->len = 0;

                for (j=0; j<10; ++j) {
                        for (i=0; i<1000; ++i) {
                                len = netlink_send(s, data);
                        }

                        ulog("%d messages have been sent to %08x.%08x.\n", i, data->id.idx, data->id.val);
                }

                return 0;
        }


        pfd.fd = s;

        while (!need_exit) {
                pfd.events = POLLIN;
                pfd.revents = 0;
                switch (poll(&pfd, 1, -1)) {
                        case 0:
                                need_exit = 1;
                                break;
                        case -1:
                                if (errno != EINTR) {
                                        need_exit = 1;
                                        break;
                                }
                                continue;
                }
                if (need_exit)
                        break;

                memset(buf, 0, sizeof(buf));
                len = recv(s, buf, sizeof(buf), 0);
                if (len == -1) {
                        perror("recv buf");
                        close(s);
                        return -1;
                }
                reply = (struct nlmsghdr *)buf;

                switch (reply->nlmsg_type) {
                case NLMSG_ERROR:
                        fprintf(out, "Error message received.\n");
                        fflush(out);
                        break;
                case NLMSG_DONE:
                        data = (struct cn_msg *)NLMSG_DATA(reply);

                        time(&tm);
                        fprintf(out, "%.24s : [%x.%x] [%08u.%08u].\n",
                                ctime(&tm), data->id.idx, data->id.val, data->seq, data->ack);
                        fflush(out);
                        break;
                default:
                        break;
                }
        }

        close(s);
        return 0;
}