/*
 * Ouroboros - Copyright (C) 2016 - 2017
 *
 * The API to instruct IPCPs
 *
 *    Dimitri Staessens <dimitri.staessens@ugent.be>
 *    Sander Vrijders   <sander.vrijders@ugent.be>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#define OUROBOROS_PREFIX "irmd/ipcp"

#include <ouroboros/config.h>
#include <ouroboros/logs.h>
#include <ouroboros/errno.h>
#include <ouroboros/utils.h>
#include <ouroboros/sockets.h>

#include "ipcp.h"

#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <stdbool.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/time.h>

static void close_ptr(void * o)
{
        close(*(int *) o);
}

ipcp_msg_t * send_recv_ipcp_msg(pid_t        api,
                                ipcp_msg_t * msg)
{
       int sockfd = 0;
       buffer_t buf;
       char * sock_path = NULL;
       ssize_t count = 0;
       ipcp_msg_t * recv_msg = NULL;
       struct timeval tv = {(SOCKET_TIMEOUT / 1000),
                            (SOCKET_TIMEOUT % 1000) * 1000};

       if (kill(api, 0) < 0)
               return NULL;

       sock_path = ipcp_sock_path(api);
       if (sock_path == NULL)
               return NULL;

       sockfd = client_socket_open(sock_path);
       if (sockfd < 0) {
               free(sock_path);
               return NULL;
       }

       free(sock_path);

       buf.len = ipcp_msg__get_packed_size(msg);
       if (buf.len == 0) {
               close(sockfd);
               return NULL;
       }

       buf.data = malloc(IPCP_MSG_BUF_SIZE);
       if (buf.data == NULL) {
               close(sockfd);
               return NULL;
       }

       if (setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO,
                      (void *) &tv, sizeof(tv)))
               log_warn("Failed to set timeout on socket.");

       pthread_cleanup_push(close_ptr, (void *) &sockfd);
       pthread_cleanup_push((void (*)(void *)) free, (void *) buf.data);

       ipcp_msg__pack(msg, buf.data);

       if (write(sockfd, buf.data, buf.len) != -1)
               count = read(sockfd, buf.data, IPCP_MSG_BUF_SIZE);

       if (count > 0)
               recv_msg = ipcp_msg__unpack(NULL, count, buf.data);

       pthread_cleanup_pop(true);
       pthread_cleanup_pop(true);

       return recv_msg;
}

pid_t ipcp_create(char *         name,
                  enum ipcp_type ipcp_type)
{
        pid_t api = -1;
        char irmd_api[10];
        size_t len = 0;
        char * ipcp_dir = "/sbin/";
        char * full_name = NULL;
        char * exec_name = NULL;
        char * argv[5];

        sprintf(irmd_api, "%u", getpid());

        api = fork();
        if (api == -1) {
                log_err("Failed to fork");
                return api;
        }

        if (api != 0)
                return api;

        if (ipcp_type == IPCP_NORMAL)
                exec_name = IPCP_NORMAL_EXEC;
        else if (ipcp_type == IPCP_SHIM_UDP)
                exec_name = IPCP_SHIM_UDP_EXEC;
        else if (ipcp_type == IPCP_SHIM_ETH_LLC)
                exec_name = IPCP_SHIM_ETH_LLC_EXEC;
        else if (ipcp_type == IPCP_LOCAL)
                exec_name = IPCP_LOCAL_EXEC;
        else
                exit(EXIT_FAILURE);

        len += strlen(INSTALL_PREFIX);
        len += strlen(ipcp_dir);
        len += strlen(exec_name);
        len += 1;

        full_name = malloc(len + 1);
        if (full_name == NULL) {
                log_err("Failed to malloc");
                exit(EXIT_FAILURE);
        }

        strcpy(full_name, INSTALL_PREFIX);
        strcat(full_name, ipcp_dir);
        strcat(full_name, exec_name);
        full_name[len] = '\0';


        /* log_file to be placed at the end */
        argv[0] = full_name;
        argv[1] = irmd_api;
        argv[2] = name;
        if (log_syslog) {
                argv[3] = "1";
                argv[4] = NULL;
        } else {
                argv[3] = NULL;
        }

        argv[4] = NULL;

        execv(argv[0], &argv[0]);

        log_dbg("%s", strerror(errno));
        log_err("Failed to load IPCP daemon");
        log_err("Make sure to run the installed version");
        free(full_name);
        exit(EXIT_FAILURE);
}

int ipcp_destroy(pid_t api)
{
        if (kill(api, SIGTERM)) {
                log_err("Failed to destroy IPCP");
                return -1;
        }

        return 0;
}

int ipcp_bootstrap(pid_t              api,
                   dif_config_msg_t * conf)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        if (conf == NULL)
                return -EINVAL;

        msg.code = IPCP_MSG_CODE__IPCP_BOOTSTRAP;
        msg.conf = conf;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_enroll(pid_t  api,
                char * dif_name)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        if (dif_name == NULL)
                return -EINVAL;

        msg.code     = IPCP_MSG_CODE__IPCP_ENROLL;
        msg.dif_name = dif_name;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_name_reg(pid_t  api,
                  char * name)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        if (name == NULL)
                return -1;

        msg.code = IPCP_MSG_CODE__IPCP_NAME_REG;
        msg.name = name;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_name_unreg(pid_t  api,
                    char * name)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        msg.code = IPCP_MSG_CODE__IPCP_NAME_UNREG;
        msg.name = name;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_name_query(pid_t api,
                    char * name)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        msg.code = IPCP_MSG_CODE__IPCP_NAME_QUERY;
        msg.name = name;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_flow_alloc(pid_t     api,
                    int       port_id,
                    pid_t     n_api,
                    char *    dst_name,
                    qoscube_t cube)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        if (dst_name == NULL)
                return -EINVAL;

        msg.code         = IPCP_MSG_CODE__IPCP_FLOW_ALLOC;
        msg.has_port_id  = true;
        msg.port_id      = port_id;
        msg.has_api      = true;
        msg.api          = n_api;
        msg.dst_name     = dst_name;
        msg.has_qoscube  = true;
        msg.qoscube      = cube;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (!recv_msg->has_result) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_flow_alloc_resp(pid_t api,
                         int   port_id,
                         pid_t n_api,
                         int   response)
{
        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        msg.code         = IPCP_MSG_CODE__IPCP_FLOW_ALLOC_RESP;
        msg.has_port_id  = true;
        msg.port_id      = port_id;
        msg.has_api      = true;
        msg.api          = n_api;
        msg.has_response = true;
        msg.response     = response;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return -1;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return -1;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}

int ipcp_flow_dealloc(pid_t api,
                      int   port_id)
{

        ipcp_msg_t msg = IPCP_MSG__INIT;
        ipcp_msg_t * recv_msg = NULL;
        int ret = -1;

        msg.code        = IPCP_MSG_CODE__IPCP_FLOW_DEALLOC;
        msg.has_port_id = true;
        msg.port_id     = port_id;

        recv_msg = send_recv_ipcp_msg(api, &msg);
        if (recv_msg == NULL)
                return 0;

        if (recv_msg->has_result == false) {
                ipcp_msg__free_unpacked(recv_msg, NULL);
                return 0;
        }

        ret = recv_msg->result;
        ipcp_msg__free_unpacked(recv_msg, NULL);

        return ret;
}
