linux c send udp

send_udp.c

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include "../common/common.h"

int sendUdpPackage(char *udpPackage, Config_INI *config) {

    struct sockaddr_in servaddr;

    bzero(&servaddr, sizeof(servaddr));

    servaddr.sin_family = AF_INET;

    int isContinue = 1; //函数是否继续执行标志 ： 1->继续 ,0->终止

    in_addr_t in_addr = inet_addr(config->udpHost);

    //如果IP解析失败则尝试域名解析
    if (in_addr == INADDR_NONE) {

        struct hostent *hp = NULL;

        //如果解析域名失败
        if ((hp = gethostbyname(config->udpHost)) == NULL) {

            TRACE_INFO("ip parse and dns resolver error.\n");

            isContinue = 0;

        } else {

            if (hp->h_length != 4) {

                //目前只支持IPV4
                TRACE_INFO("only support IPV4.\n");

                isContinue = 0;

            } else {

                memcpy(&servaddr.sin_addr, hp->h_addr_list[0], hp->h_length);

            }

        }

    } else {

        servaddr.sin_addr.s_addr = in_addr;

    }

    //如果到目前已经不能继续执行，则返回
    if (!isContinue) {

        return 0;

    }

    servaddr.sin_port = htons(config->udpPort);

    int fd = socket(AF_INET, SOCK_DGRAM, 0);

    if (fd < 0) {

        TRACE_INFO("cannot open udp socket.\n");

        return 0;

    }

    if (sendto(fd, udpPackage, strlen(udpPackage), 0, // +1 to include terminator
               (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0) {

        TRACE_INFO("send udp message fail.\n");

        close(fd);

        return 0;

    }

    close(fd);

    return 1;

}

linux 发送UDP ，兼容IP和域名