/*
 * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
 *               2005-2007 Takahiro Hirofuchi
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <sys/stat.h>
#include <sysfs/libsysfs.h>

#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include <fcntl.h>
#include <getopt.h>
#include <unistd.h>
#include <errno.h>

#include "vhci_driver.h"
#include "usbip_common.h"
#include "usbip_network.h"
#include "usbip.h"

static const char usbip_attach_usage_string[] =
        "usbip attach <args>\n"
        "    -r, --remote=<host>      The machine with exported USB devices\n"
        "    -b, --busid=<busid>    Busid of the device on <host>\n";

void usbip_attach_usage(void)
{
        printf("usage: %s", usbip_attach_usage_string);
}

#define MAX_BUFF 100
static int record_connection(char *host, char *port, char *busid, int rhport)
{
        int fd;
        char path[PATH_MAX+1];
        char buff[MAX_BUFF+1];
        int ret;

        ret = mkdir(VHCI_STATE_PATH, 0700);
        if (ret < 0) {
                /* if VHCI_STATE_PATH exists, then it better be a directory */
                if (errno == EEXIST) {
                        struct stat s;
                        ret = stat(VHCI_STATE_PATH, &s);
                        if (ret < 0)
                                return -1;
                        if (!(s.st_mode & S_IFDIR))
                                return -1;
                } else
                        return -1;
        }

        snprintf(path, PATH_MAX, VHCI_STATE_PATH"/port%d", rhport);

        fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU);
        if (fd < 0)
                return -1;

        snprintf(buff, MAX_BUFF, "%s %s %s\n",
                        host, port, busid);

        ret = write(fd, buff, strlen(buff));
        if (ret != (ssize_t) strlen(buff)) {
                close(fd);
                return -1;
        }

        close(fd);

        return 0;
}

static int import_device(int sockfd, struct usbip_usb_device *udev)
{
        int rc;
        int port;

        rc = usbip_vhci_driver_open();
        if (rc < 0) {
                err("open vhci_driver");
                return -1;
        }

        port = usbip_vhci_get_free_port();
        if (port < 0) {
                err("no free port");
                usbip_vhci_driver_close();
                return -1;
        }

        rc = usbip_vhci_attach_device(port, sockfd, udev->busnum,
                                      udev->devnum, udev->speed);
        if (rc < 0) {
                err("import device");
                usbip_vhci_driver_close();
                return -1;
        }

        usbip_vhci_driver_close();

        return port;
}

static int query_import_device(int sockfd, char *busid)
{
        int rc;
        struct op_import_request request;
        struct op_import_reply   reply;
        uint16_t code = OP_REP_IMPORT;

        memset(&request, 0, sizeof(request));
        memset(&reply, 0, sizeof(reply));

        /* send a request */
        rc = usbip_net_send_op_common(sockfd, OP_REQ_IMPORT, 0);
        if (rc < 0) {
                err("send op_common");
                return -1;
        }

        strncpy(request.busid, busid, SYSFS_BUS_ID_SIZE-1);

        PACK_OP_IMPORT_REQUEST(0, &request);

        rc = usbip_net_send(sockfd, (void *) &request, sizeof(request));
        if (rc < 0) {
                err("send op_import_request");
                return -1;
        }

        /* recieve a reply */
        rc = usbip_net_recv_op_common(sockfd, &code);
        if (rc < 0) {
                err("recv op_common");
                return -1;
        }

        rc = usbip_net_recv(sockfd, (void *) &reply, sizeof(reply));
        if (rc < 0) {
                err("recv op_import_reply");
                return -1;
        }

        PACK_OP_IMPORT_REPLY(0, &reply);

        /* check the reply */
        if (strncmp(reply.udev.busid, busid, SYSFS_BUS_ID_SIZE)) {
                err("recv different busid %s", reply.udev.busid);
                return -1;
        }

        /* import a device */
        return import_device(sockfd, &reply.udev);
}

static int attach_device(char *host, char *busid)
{
        int sockfd;
        int rc;
        int rhport;

        sockfd = usbip_net_tcp_connect(host, USBIP_PORT_STRING);
        if (sockfd < 0) {
                err("tcp connect");
                return -1;
        }

        rhport = query_import_device(sockfd, busid);
        if (rhport < 0) {
                err("query");
                return -1;
        }

        close(sockfd);

        rc = record_connection(host, USBIP_PORT_STRING, busid, rhport);
        if (rc < 0) {
                err("record connection");
                return -1;
        }

        return 0;
}

int usbip_attach(int argc, char *argv[])
{
        static const struct option opts[] = {
                { "remote", required_argument, NULL, 'r' },
                { "busid",  required_argument, NULL, 'b' },
                { NULL, 0,  NULL, 0 }
        };
        char *host = NULL;
        char *busid = NULL;
        int opt;
        int ret = -1;

        for (;;) {
                opt = getopt_long(argc, argv, "r:b:", opts, NULL);

                if (opt == -1)
                        break;

                switch (opt) {
                case 'r':
                        host = optarg;
                        break;
                case 'b':
                        busid = optarg;
                        break;
                default:
                        goto err_out;
                }
        }

        if (!host || !busid)
                goto err_out;

        ret = attach_device(host, busid);
        goto out;

err_out:
        usbip_attach_usage();
out:
        return ret;
}