/*
 * 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/socket.h>

#include <string.h>

#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/tcp.h>
#include <unistd.h>

#include "usbip_common.h"
#include "usbip_network.h"

void usbip_net_pack_uint32_t(int pack, uint32_t *num)
{
        uint32_t i;

        if (pack)
                i = htonl(*num);
        else
                i = ntohl(*num);

        *num = i;
}

void usbip_net_pack_uint16_t(int pack, uint16_t *num)
{
        uint16_t i;

        if (pack)
                i = htons(*num);
        else
                i = ntohs(*num);

        *num = i;
}

void usbip_net_pack_usb_device(int pack, struct usbip_usb_device *udev)
{
        usbip_net_pack_uint32_t(pack, &udev->busnum);
        usbip_net_pack_uint32_t(pack, &udev->devnum);
        usbip_net_pack_uint32_t(pack, &udev->speed);

        usbip_net_pack_uint16_t(pack, &udev->idVendor);
        usbip_net_pack_uint16_t(pack, &udev->idProduct);
        usbip_net_pack_uint16_t(pack, &udev->bcdDevice);
}

void usbip_net_pack_usb_interface(int pack __attribute__((unused)),
                                  struct usbip_usb_interface *udev
                                  __attribute__((unused)))
{
        /* uint8_t members need nothing */
}

static ssize_t usbip_net_xmit(int sockfd, void *buff, size_t bufflen,
                              int sending)
{
        ssize_t nbytes;
        ssize_t total = 0;

        if (!bufflen)
                return 0;

        do {
                if (sending)
                        nbytes = send(sockfd, buff, bufflen, 0);
                else
                        nbytes = recv(sockfd, buff, bufflen, MSG_WAITALL);

                if (nbytes <= 0)
                        return -1;

                buff     = (void *)((intptr_t) buff + nbytes);
                bufflen -= nbytes;
                total   += nbytes;

        } while (bufflen > 0);

        return total;
}

ssize_t usbip_net_recv(int sockfd, void *buff, size_t bufflen)
{
        return usbip_net_xmit(sockfd, buff, bufflen, 0);
}

ssize_t usbip_net_send(int sockfd, void *buff, size_t bufflen)
{
        return usbip_net_xmit(sockfd, buff, bufflen, 1);
}

int usbip_net_send_op_common(int sockfd, uint32_t code, uint32_t status)
{
        struct op_common op_common;
        int rc;

        memset(&op_common, 0, sizeof(op_common));

        op_common.version = USBIP_VERSION;
        op_common.code    = code;
        op_common.status  = status;

        PACK_OP_COMMON(1, &op_common);

        rc = usbip_net_send(sockfd, &op_common, sizeof(op_common));
        if (rc < 0) {
                dbg("usbip_net_send failed: %d", rc);
                return -1;
        }

        return 0;
}

int usbip_net_recv_op_common(int sockfd, uint16_t *code)
{
        struct op_common op_common;
        int rc;

        memset(&op_common, 0, sizeof(op_common));

        rc = usbip_net_recv(sockfd, &op_common, sizeof(op_common));
        if (rc < 0) {
                dbg("usbip_net_recv failed: %d", rc);
                goto err;
        }

        PACK_OP_COMMON(0, &op_common);

        if (op_common.version != USBIP_VERSION) {
                dbg("version mismatch: %d %d", op_common.version,
                    USBIP_VERSION);
                goto err;
        }

        switch (*code) {
        case OP_UNSPEC:
                break;
        default:
                if (op_common.code != *code) {
                        dbg("unexpected pdu %#0x for %#0x", op_common.code,
                            *code);
                        goto err;
                }
        }

        if (op_common.status != ST_OK) {
                dbg("request failed at peer: %d", op_common.status);
                goto err;
        }

        *code = op_common.code;

        return 0;
err:
        return -1;
}

int usbip_net_set_reuseaddr(int sockfd)
{
        const int val = 1;
        int ret;

        ret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
        if (ret < 0)
                dbg("setsockopt: SO_REUSEADDR");

        return ret;
}

int usbip_net_set_nodelay(int sockfd)
{
        const int val = 1;
        int ret;

        ret = setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val));
        if (ret < 0)
                dbg("setsockopt: TCP_NODELAY");

        return ret;
}

int usbip_net_set_keepalive(int sockfd)
{
        const int val = 1;
        int ret;

        ret = setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &val, sizeof(val));
        if (ret < 0)
                dbg("setsockopt: SO_KEEPALIVE");

        return ret;
}

/*
 * IPv6 Ready
 */
int usbip_net_tcp_connect(char *hostname, char *service)
{
        struct addrinfo hints, *res, *rp;
        int sockfd;
        int ret;

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;

        /* get all possible addresses */
        ret = getaddrinfo(hostname, service, &hints, &res);
        if (ret < 0) {
                dbg("getaddrinfo: %s service %s: %s", hostname, service,
                    gai_strerror(ret));
                return ret;
        }

        /* try the addresses */
        for (rp = res; rp; rp = rp->ai_next) {
                sockfd = socket(rp->ai_family, rp->ai_socktype,
                                rp->ai_protocol);
                if (sockfd < 0)
                        continue;

                /* should set TCP_NODELAY for usbip */
                usbip_net_set_nodelay(sockfd);
                /* TODO: write code for heartbeat */
                usbip_net_set_keepalive(sockfd);

                if (connect(sockfd, rp->ai_addr, rp->ai_addrlen) == 0)
                        break;

                close(sockfd);
        }

        freeaddrinfo(res);

        if (!rp)
                return EAI_SYSTEM;

        return sockfd;
}