linux c语言udp 多线程socket接受192.168.1.1的信息发送给127.0.0.1，接受192.168.131.1的信息发送给127.0.0.2

好的，这个问题需要使用多线程来同时接收来自192.168.1.1和192.168.131.1的数据包，并将它们分别发送到127.0.0.1和127.0.0.2。以下是一个简单的多线程示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <unistd.h>

#define BUF_SIZE 1024
#define SRC_IP1 "192.168.1.1"
#define SRC_IP2 "192.168.131.1"
#define DST_IP1 "127.0.0.1"
#define DST_IP2 "127.0.0.2"
#define SRC_PORT 8080
#define DST_PORT1 8081
#define DST_PORT2 8082

// 线程参数结构体
struct thread_param {
    int sock;
    struct sockaddr_in addr;
};

// 接收数据并发送的线程函数
void* recv_send_thread(void* arg) {
    struct thread_param* param = (struct thread_param*)arg;
    int sock = param->sock;
    struct sockaddr_in addr = param->addr;
    char buf[BUF_SIZE];
    int ret;

    // 从指定地址接收数据并发送到指定地址
    while (1) {
        memset(buf, 0, sizeof(buf));
        ret = recvfrom(sock, buf, sizeof(buf), 0, NULL, NULL);
        if (ret < 0) {
            perror("recvfrom error");
            break;
        }
        if (addr.sin_addr.s_addr == inet_addr(SRC_IP1)) {
            ret = sendto(sock, buf, strlen(buf), 0, (struct sockaddr*)&(struct sockaddr_in){AF_INET, htons(DST_PORT1), inet_addr(DST_IP1)}, sizeof(struct sockaddr_in));
        } else if (addr.sin_addr.s_addr == inet_addr(SRC_IP2)) {
            ret = sendto(sock, buf, strlen(buf), 0, (struct sockaddr*)&(struct sockaddr_in){AF_INET, htons(DST_PORT2), inet_addr(DST_IP2)}, sizeof(struct sockaddr_in));
        }
        if (ret < 0) {
            perror("sendto error");
            break;
        }
    }

    // 释放线程参数内存
    free(param);

    return NULL;
}

int main() {
    int sock1, sock2, ret;
    struct sockaddr_in addr1, addr2;

    // 创建接收端UDP socket1
    sock1 = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock1 < 0) {
        perror("socket create error");
        return -1;
    }

    // 绑定接收端IP1和端口
    memset(&addr1, 0, sizeof(addr1));
    addr1.sin_family = AF_INET;
    addr1.sin_port = htons(SRC_PORT);
    addr1.sin_addr.s_addr = inet_addr(SRC_IP1);
    if (bind(sock1, (struct sockaddr*)&addr1, sizeof(addr1)) < 0) {
        perror("bind error");
        close(sock1);
        return -1;
    }

    // 创建接收端UDP socket2
    sock2 = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock2 < 0) {
        perror("socket create error");
        close(sock1);
        return -1;
    }

    // 绑定接收端IP2和端口
    memset(&addr2, 0, sizeof(addr2));
    addr2.sin_family = AF_INET;
    addr2.sin_port = htons(SRC_PORT);
    addr2.sin_addr.s_addr = inet_addr(SRC_IP2);
    if (bind(sock2, (struct sockaddr*)&addr2, sizeof(addr2)) < 0) {
        perror("bind error");
        close(sock1);
        close(sock2);
        return -1;
    }

    // 创建线程1用于接收来自192.168.1.1的数据包并发送到127.0.0.1
    pthread_t tid1;
    struct thread_param* param1 = (struct thread_param*)malloc(sizeof(struct thread_param));
    param1->sock = sock1;
    param1->addr = addr1;
    ret = pthread_create(&tid1, NULL, recv_send_thread, param1);
    if (ret < 0) {
        perror("pthread_create error");
        close(sock1);
        close(sock2);
        free(param1);
        return -1;
    }

    // 创建线程2用于接收来自192.168.131.1的数据包并发送到127.0.0.2
    pthread_t tid2;
    struct thread_param* param2 = (struct thread_param*)malloc(sizeof(struct thread_param));
    param2->sock = sock2;
    param2->addr = addr2;
    ret = pthread_create(&tid2, NULL, recv_send_thread, param2);
    if (ret < 0) {
        perror("pthread_create error");
        close(sock1);
        close(sock2);
        free(param1);
        free(param2);
        return -1;
    }

    // 等待线程退出
    pthread_join(tid1, NULL);
    pthread_join(tid2, NULL);

    // 关闭socket
    close(sock1);
    close(sock2);

    return 0;
}

该示例代码中，我们首先创建了两个UDP socket用于分别接收来自192.168.1.1和192.168.131.1的数据包，并绑定了IP地址和端口。然后，我们创建了两个线程，分别用于接收数据并发送到指定地址。最后，我们等待线程退出并关闭socket。

注意：本示例代码仅供参考，实际应用中还需要进行错误处理、超时处理等。