c语言实现端口全扫描
时间: 2024-10-10 11:02:08 浏览: 5
在C语言中实现端口扫描通常涉及到网络编程,特别是使用套接字(sockets)来检测目标主机上哪些端口开放。这里是一个基本的概念示例,展示如何使用UDP协议进行简单扫描:
```c
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#define PORTS_TO_SCAN 100 // 要扫描的端口号范围
void port_scan(int sockfd, struct sockaddr_in server_address) {
int i;
for (i = 80; i <= PORTS_TO_SCAN; ++i) { // 示例仅扫描80到100端口
struct sockaddr_in client_address;
bzero(&client_address, sizeof(client_address));
client_address.sin_family = AF_INET;
client_address.sin_port = htons(i); // 设置目标端口
client_address.sin_addr.s_addr = htonl(INADDR_ANY);
socklen_t addrlen = sizeof(client_address);
if (connect(sockfd, (struct sockaddr *)&client_address, addrlen) == -1) {
perror("Failed to connect");
continue;
}
printf("Port %d is open.\n", ntohs(client_address.sin_port));
close(sockfd); // 关闭连接
}
}
int main() {
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd == -1) {
perror("Failed to create socket");
return 1;
}
struct sockaddr_in server_address;
bzero(&server_address, sizeof(server_address));
server_address.sin_family = AF_INET;
server_address.sin_port = htons(67); // 使用熟知的端口(如DNS)
server_address.sin_addr.s_addr = INADDR_ANY;
if (bind(sockfd, (struct sockaddr *)&server_address, sizeof(server_address)) == -1) {
perror("Failed to bind");
return 1;
}
port_scan(sockfd, server_address);
close(sockfd);
return 0;
}
```