HAL_UDP_lwip.c

/*
 * Tencent is pleased to support the open source community by making IoT Hub available.
 * Copyright (C) 2016 THL A29 Limited, a Tencent company. All rights reserved.

 * Licensed under the MIT License (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://opensource.org/licenses/MIT

 * Unless required by applicable law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

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

#include "lwip/sockets.h"
#include "lwip/netdb.h"
#include "lwip/inet.h"

#include "qcloud_iot_import.h"
#include "qcloud_iot_export_log.h"
#include "qcloud_iot_export_error.h"

#ifdef COAP_COMM_ENABLED

/* lwIP socket handle start from 0 */
#define LWIP_SOCKET_FD_SHIFT 3

uintptr_t HAL_UDP_Connect(const char *host, unsigned short port)
{
#define NETWORK_ADDR_LEN    (16)

    int ret;
    struct addrinfo         hints, *addr_list, *cur;
    int fd = 0;

    char                    port_str[6] = {0};
    HAL_Snprintf(port_str, 6, "%d", port);

    memset((char *)&hints, 0x00, sizeof(hints));
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_family = AF_INET;
    hints.ai_protocol = IPPROTO_UDP;

    Log_d("establish tcp connection with server(host=%s port=%s)", host, port_str);

    if (getaddrinfo(host, port_str, &hints, &addr_list) != 0) {        
		Log_e("getaddrinfo error,errno:%s",strerror(errno));
        return 0;
    }

    for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
		fd = socket(cur->ai_family, cur->ai_socktype, cur->ai_protocol);
		if (fd < 0) {
			ret = 0;
			continue;
		}

		if (0 == connect(fd, cur->ai_addr, cur->ai_addrlen)) {
			ret = fd + LWIP_SOCKET_FD_SHIFT;
			break;
		}

		close(fd);
		ret = 0;
    }

    if (0 == ret) {
        Log_e("fail to establish udp");
    } else {
        Log_d("success to establish udp, fd=%d", ret);
    }

    freeaddrinfo(addr_list);

    return (uintptr_t)ret;

#undef NETWORK_ADDR_LEN
}

void HAL_UDP_Disconnect(uintptr_t fd)
{
    long            socket_id = -1;
    fd -= LWIP_SOCKET_FD_SHIFT;
    
    socket_id = (int)fd;
    close(socket_id);
}

int HAL_UDP_Write(uintptr_t fd, const unsigned char *p_data, unsigned int datalen)
{
    int             rc = -1;
    long            socket_id = -1;
    fd -= LWIP_SOCKET_FD_SHIFT;
    
    socket_id = (int)fd;
    rc = send(socket_id, (char *)p_data, (int)datalen, 0);
    if (-1 == rc) {
        return -1;
    }

    return rc;
}

int HAL_UDP_Read(uintptr_t fd, unsigned char *p_data, unsigned int datalen)
{
    long            socket_id = -1;
    int             count = -1;
    fd -= LWIP_SOCKET_FD_SHIFT;
    
    socket_id = (int)fd;
    count = (int)read(socket_id, p_data, datalen);

    return count;
}

int HAL_UDP_ReadTimeout(uintptr_t fd, unsigned char *p_data, unsigned int datalen, unsigned int timeout_ms)
{
    int                 ret;
    struct timeval      tv;
    fd_set              read_fds;
    int                socket_id = -1;
    fd -= LWIP_SOCKET_FD_SHIFT;
    
    socket_id = (int)fd;

    if (socket_id < 0) {
        return -1;
    }

    FD_ZERO(&read_fds);
    FD_SET(socket_id, &read_fds);

    tv.tv_sec  = timeout_ms / 1000;
    tv.tv_usec = (timeout_ms % 1000) * 1000;

    ret = select(socket_id + 1, &read_fds, NULL, NULL, timeout_ms == 0 ? NULL : &tv);

    /* Zero fds ready means we timed out */
    if (ret == 0) {
        return QCLOUD_ERR_SSL_READ_TIMEOUT;    /* receive timeout */
    }

    if (ret < 0) {
        if (errno == EINTR) {
            return -3;    /* want read */
        }

        return QCLOUD_ERR_SSL_READ; /* receive failed */
    }

    /* This call will not block */
    return HAL_UDP_Read(fd, p_data, datalen);
}

#endif