/*
 * File      : sal_socket.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2018, RT-Thread Development Team
 *
 *  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.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-05-23     ChenYong     First version
 */

#include <rtthread.h>
#include <rthw.h>

#include <sal_socket.h>
#include <sal_netdb.h>
#include <sal.h>

#define DBG_ENABLE
#define DBG_SECTION_NAME    "SAL_SOC"
#define DBG_LEVEL           DBG_INFO
#define DBG_COLOR
#include <rtdbg.h>

/* the socket table used to dynamic allocate sockets */
struct sal_socket_table
{
    uint32_t max_socket;
    struct sal_socket **sockets;
};

/* The global array of available protocol families */
static struct proto_family proto_families[SAL_PROTO_FAMILIES_NUM];
/* The global socket table */
static struct sal_socket_table socket_table;
static struct rt_mutex sal_core_lock;
static rt_bool_t init_ok = RT_FALSE;

/**
 * SAL (Socket Abstraction Layer) initialization.
 *
 * @return result
 *         >= 0: initialize success
 */
int sal_init(void)
{
    if(init_ok)
    {
        LOG_D("Socket Abstraction Layer is already initialized.");
        return 0;
    }

    /* clean sal socket table */
    memset(&socket_table, 0, sizeof(socket_table));
    /* create sal socket lock */
    rt_mutex_init(&sal_core_lock, "sal_lock", RT_IPC_FLAG_FIFO);

    LOG_I("Socket Abstraction Layer initialize success.");
    init_ok = RT_TRUE;

    return 0;
}
INIT_COMPONENT_EXPORT(sal_init);

/**
 *  this function will register the current protocol family to the global array of protocol families.
 *
 * @param pf protocol families structure
 *
 * @return 0 : protocol families structure index
 *        -1 : the global array of available protocol families is full
 */
int sal_proto_family_register(const struct proto_family *pf)
{
    rt_base_t level;
    int idx;

    /* disable interrupt */
    level = rt_hw_interrupt_disable();

    /* find an empty protocol family entry */
    for(idx = 0; idx < SAL_PROTO_FAMILIES_NUM && proto_families[idx].create; idx++);

    /* can't find an empty protocol family entry */
    if(idx == SAL_PROTO_FAMILIES_NUM)
    {
        /* enable interrupt */
        rt_hw_interrupt_enable(level);

        return -1;
    }

    proto_families[idx].family = pf->family;
    proto_families[idx].sec_family = pf->sec_family;
    proto_families[idx].create = pf->create;

    proto_families[idx].gethostbyname = pf->gethostbyname;
    proto_families[idx].gethostbyname_r = pf->gethostbyname_r;
    proto_families[idx].freeaddrinfo = pf->freeaddrinfo;
    proto_families[idx].getaddrinfo = pf->getaddrinfo;

    /* enable interrupt */
    rt_hw_interrupt_enable(level);

    return 0;
}

/**
 *  this function will get socket structure by sal socket descriptor
 *
 * @param socket sal socket index
 *
 * @return socket structure of the current sal socket index
 */
struct sal_socket *sal_get_socket(int socket)
{
    struct sal_socket_table *st = &socket_table;

    if (socket < 0 || socket >= (int) st->max_socket)
    {
        return RT_NULL;
    }

    socket = socket - SAL_SOCKET_OFFSET;
    /* check socket structure valid or not */
    if (st->sockets[socket]->magic != SAL_SOCKET_MAGIC)
    {
        return RT_NULL;
    }

    return st->sockets[socket];
}

/**
 * this function will lock sal socket.
 *
 * @note please don't invoke it on ISR.
 */
static void sal_lock(void)
{
    rt_err_t result;

    result = rt_mutex_take(&sal_core_lock, RT_WAITING_FOREVER);
    if (result != RT_EOK)
    {
        RT_ASSERT(0);
    }
}

/**
 * this function will lock sal socket.
 *
 * @note please don't invoke it on ISR.
 */
static void sal_unlock(void)
{
    rt_mutex_release(&sal_core_lock);
}

/**
 *  this function will get protocol family structure by family type
 *
 * @param family  protocol family
 *
 * @return protocol family structure address
 */
static struct proto_family *get_proto_family(int family)
{
    int idx;

    for (idx = 0; idx < SAL_PROTO_FAMILIES_NUM; idx++)
    {
        if (proto_families[idx].family == family && proto_families[idx].create)
        {
            return &proto_families[idx];
        }
    }
    /* compare the secondary protocol families when primary protocol families find failed */
    for (idx = 0; idx < SAL_PROTO_FAMILIES_NUM; idx++)
    {
        if (proto_families[idx].sec_family == family && proto_families[idx].create)
        {
            return &proto_families[idx];
        }
    }

    return RT_NULL;
}

/**
 *  this function will initialize socket structure and set socket options
 *
 * @param family    protocol family
 * @param type      socket type
 * @param protocol  transfer Protocol
 * @param res       socket structure address
 *
 * @return  0 : socket initialize success
 *         -1 : input the wrong family
 *         -2 : input the wrong socket type
 *         -3 : get protocol family structure failed
 *         -4 : set socket options failed
 */
static int socket_init(int family, int type, int protocol, struct sal_socket **res)
{
    struct sal_socket *sock;
    struct proto_family *pf;

    if (family < 0 || family > AF_MAX)
    {
        return -1;
    }

    if (type < 0 || type > SOCK_MAX)
    {
        return -2;
    }

    sock = *res;
    sock->domain = family;
    sock->type = type;
    sock->protocol = protocol;

    /* get socket protocol family structure */
    if ((pf = get_proto_family(family)) == RT_NULL)
    {
        return -3;
    }

    /* registered the current socket options */
    if (pf->create(sock, type, protocol) != 0)
    {
        return -4;
    }

    return 0;
}

static int socket_alloc(struct sal_socket_table *st, int f_socket)
{
    int idx;

    /* find an empty socket entry */
    for (idx = f_socket; idx < (int) st->max_socket; idx++)
    {
        if (st->sockets[idx] == RT_NULL)
            break;
        if (st->sockets[idx]->ops == RT_NULL)
            break;
    }

    /* allocate a larger sockte container */
    if (idx == (int) st->max_socket &&  st->max_socket < SAL_SOCKETS_NUM)
    {
        int cnt, index;
        struct sal_socket **sockets;

        /* increase the number of FD with 4 step length */
        cnt = st->max_socket + 4;
        cnt = cnt > SAL_SOCKETS_NUM ? SAL_SOCKETS_NUM : cnt;

        sockets = rt_realloc(st->sockets, cnt * sizeof(struct sal_socket *));
        if (sockets == RT_NULL)
            goto __result; /* return st->max_socket */

        /* clean the new allocated fds */
        for (index = st->max_socket; index < cnt; index++)
        {
            sockets[index] = RT_NULL;
        }

        st->sockets = sockets;
        st->max_socket = cnt;
    }

    /* allocate  'struct sal_socket' */
    if (idx < (int) st->max_socket && st->sockets[idx] == RT_NULL)
    {
        st->sockets[idx] = rt_malloc(sizeof(struct sal_socket));
        if (st->sockets[idx] == RT_NULL)
        {
            idx = st->max_socket;
        }
    }

__result:
    return idx;

}

/**
 * this function will return a empty sal socket structure address
 *
 * @return sal socket structure address
 */
static int socket_new(void)
{
    struct sal_socket *sock;
    struct sal_socket_table *st = &socket_table;
    int idx;

    sal_lock();

    /* find an empty sal socket entry */
    idx = socket_alloc(st, 0);

    /* can't find an empty sal socket entry */
    if (idx == (int) st->max_socket)
    {
        idx = -(1 + SAL_SOCKET_OFFSET);
        goto __result;
    }

    sock = st->sockets[idx];
    sock->socket = idx + SAL_SOCKET_OFFSET;
    sock->magic = SAL_SOCKET_MAGIC;

__result:
    sal_unlock();
    return idx + SAL_SOCKET_OFFSET;
}

int sal_accept(int socket, struct sockaddr *addr, socklen_t *addrlen)
{
    int new_socket;
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->accept == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    new_socket = sock->ops->accept((int) sock->user_data, addr, addrlen);
    if (new_socket != -1)
    {
        int retval;
        int new_socket;
        struct sal_socket *new_sock;

        /* allocate a new socket structure and registered socket options */
        new_socket = socket_new();
        if (new_socket < 0)
        {
            return -1;
        }
        new_sock = sal_get_socket(new_socket);

        retval = socket_init(sock->domain, sock->type, sock->protocol, &new_sock);
        if (retval < 0)
        {
            LOG_E("New socket registered failed, return error %d.", retval);
            return -1;
        }

        /* socket struct user_data used to store the acquired new socket */
        new_sock->user_data = (void *) new_socket;

        return new_sock->socket;
    }

    return -1;
}

int sal_bind(int socket, const struct sockaddr *name, socklen_t namelen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->bind == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->bind((int) sock->user_data, name, namelen);
}

int sal_shutdown(int socket, int how)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->shutdown == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    if (sock->ops->shutdown((int) sock->user_data, how) == 0)
    {
        memset(sock, 0x00, sizeof(struct sal_socket));
        return 0;
    }

    return -1;
}

int sal_getpeername(int socket, struct sockaddr *name, socklen_t *namelen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->getpeername == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->getpeername((int) sock->user_data, name, namelen);
}

int sal_getsockname(int socket, struct sockaddr *name, socklen_t *namelen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->getsockname == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->getsockname((int) sock->user_data, name, namelen);
}

int sal_getsockopt(int socket, int level, int optname, void *optval, socklen_t *optlen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->getsockopt == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->getsockopt((int) sock->user_data, level, optname, optval, optlen);
}

int sal_setsockopt(int socket, int level, int optname, const void *optval, socklen_t optlen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->setsockopt == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->setsockopt((int) sock->user_data, level, optname, optval, optlen);
}

int sal_connect(int socket, const struct sockaddr *name, socklen_t namelen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->connect == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->connect((int) sock->user_data, name, namelen);
}

int sal_listen(int socket, int backlog)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->listen == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->listen((int) sock->user_data, backlog);
}

int sal_recvfrom(int socket, void *mem, size_t len, int flags,
             struct sockaddr *from, socklen_t *fromlen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->recvfrom == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->recvfrom((int) sock->user_data, mem, len, flags, from, fromlen);
}

int sal_sendto(int socket, const void *dataptr, size_t size, int flags,
           const struct sockaddr *to, socklen_t tolen)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->sendto == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->sendto((int) sock->user_data, dataptr, size, flags, to, tolen);
}

int sal_socket(int domain, int type, int protocol)
{
    int retval;
    int socket, proto_socket;
    struct sal_socket *sock;

    /* allocate a new socket and registered socket options */
    socket = socket_new();
    if (socket < 0)
    {
        return -1;
    }
    sock = sal_get_socket(socket);

    retval = socket_init(domain, type, protocol, &sock);
    if (retval < 0)
    {
        LOG_E("SAL socket protocol family input failed, return error %d.", retval);
        return -1;
    }

    if (sock->ops->socket == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    proto_socket = sock->ops->socket(domain, type, protocol);
    if (proto_socket >= 0)
    {
        sock->user_data = (void *) proto_socket;

        return sock->socket;
    }

    return -1;
}

int sal_closesocket(int socket)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->closesocket == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    if (sock->ops->closesocket((int) sock->user_data) == 0)
    {
        memset(sock, 0x00, sizeof(struct sal_socket));
        return 0;
    }

    return -1;
}

int sal_ioctlsocket(int socket, long cmd, void *arg)
{
    struct sal_socket *sock;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->ioctlsocket == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->ioctlsocket((int) sock->user_data, cmd, arg);
}

int sal_poll(struct dfs_fd *file, struct rt_pollreq *req)
{
    struct sal_socket *sock;
    int socket = (int) file->data;

    sock = sal_get_socket(socket);
    if (!sock)
    {
        return -1;
    }

    if (sock->ops->poll == RT_NULL)
    {
        return -RT_ENOSYS;
    }

    return sock->ops->poll(file, req);
}

struct hostent *sal_gethostbyname(const char *name)
{
    int i;

    for (i = 0; i < SAL_PROTO_FAMILIES_NUM; ++i)
    {
        if (proto_families[i].gethostbyname)
        {
            return proto_families[i].gethostbyname(name);
        }
    }

    return RT_NULL;
}

int sal_gethostbyname_r(const char *name, struct hostent *ret, char *buf,
                size_t buflen, struct hostent **result, int *h_errnop)
{
    int i;

    for (i = 0; i < SAL_PROTO_FAMILIES_NUM; ++i)
    {
        if (proto_families[i].gethostbyname_r)
        {
            return proto_families[i].gethostbyname_r(name, ret, buf, buflen, result, h_errnop);
        }
    }

    return -1;
}

void sal_freeaddrinfo(struct addrinfo *ai)
{
    int i;

    for (i = 0; i < SAL_PROTO_FAMILIES_NUM; ++i)
    {
        if (proto_families[i].freeaddrinfo)
        {
            proto_families[i].freeaddrinfo(ai);
            return;
        }
    }
}

int sal_getaddrinfo(const char *nodename,
       const char *servname,
       const struct addrinfo *hints,
       struct addrinfo **res)
{
    int i;

    for (i = 0; i < SAL_PROTO_FAMILIES_NUM; ++i)
    {
        if (proto_families[i].getaddrinfo)
        {
            return proto_families[i].getaddrinfo(nodename, servname, hints, res);
        }
    }

    return -1;
}