TCP/IP网络程序编程——端口扫描程序UDP

程序代码

1.  
   #include<cstdio>
2.  
   #include<cstdlib>
3.  
   #include<sys/socket.h>
4.  
   #include<sys/types.h>
5.  
   #include<unistd.h>
6.  
   #include<arpa/inet.h>
7.  
   #include<netinet/in.h>
8.  
   #include<netinet/ip_icmp.h>
9.  
   #include<netinet/ip.h>
10.  
    #include<netinet/in_systm.h>
11.  
    #include<netdb.h>
12.  
    #include<cstring>
13.  
    #include<sys/time.h>
14.  
     
15.  
     
16.  
    #define CHKADDRESS(_saddr_)\
17.  
    {\
18.  
    u_char *p=(u_char*)&(_saddr_);\
19.  
    if((p[0]==10)||(p[0]==168&&16<=p[1]&&p[1]<=31)||(p[0]==192&&p[1]==168))\
20.  
    ;\
21.  
    else{\
22.  
    fprintf(stderr,"ip address error!\n");\
23.  
    exit(EXIT_FAILURE);\
24.  
    }\
25.  
    }
26.  
     
27.  
     
28.  
    enum{ CMD_NAME,DST_IP,START_PORT,LAST_IP};
29.  
     
30.  
    #define MAXBUFF 8192
31.  
     
32.  
    int main(int argc,char** argv)
33.  
    {
34.  
    struct icmp* icmp;
35.  
    fd_set select_fd;
36.  
    struct sockaddr_in send_sa;
37.  
    int recv_sd;
38.  
    int send_sd;
39.  
    char buff[MAXBUFF]; //接受包使用的缓存区
40.  
     
41.  
    int end_port;
42.  
    int start_port;
43.  
    int dstport;
44.  
    struct timeval tv;
45.  
     
46.  
    if(argc!=4)
47.  
    {
48.  
    fprintf(stderr," usage:%s dst_ip start_port end_port\n",argv[CMD_NAME]);
49.  
    exit(EXIT_FAILURE);
50.  
    }
51.  
     
52.  
    send_sa.sin_addr.s_addr=inet_addr(argv[DST_IP]);
53.  
    send_sa.sin_family=AF_INET;
54.  
     
55.  
    start_port=atoi(argv[START_PORT]);
56.  
    end_port=atoi(argv[LAST_IP]);
57.  
     
58.  
    CHKADDRESS(send_sa.sin_addr.s_addr);
59.  
     
60.  
    if((send_sd=socket(AF_INET,SOCK_DGRAM,0))<0)
61.  
    {
62.  
    perror("socket(sock_raw)");
63.  
    exit(EXIT_FAILURE);
64.  
    }
65.  
     
66.  
    if((recv_sd=socket(AF_INET,SOCK_RAW,IPPROTO_ICMP))<0)
67.  
    {
68.  
    perror("scok_raw");
69.  
    exit(EXIT_FAILURE);
70.  
    }
71.  
     
72.  
     
73.  
    for(dstport=start_port;dstport<=end_port;dstport )
74.  
    {
75.  
    printf("scan port %d\r",dstport);
76.  
    fflush(stdout);
77.  
     
78.  
    send_sa.sin_port=htons(dstport);
79.  
    sendto(send_sd,NULL,0,0,(struct sockaddr*)&send_sa,sizeof(send_sa));
80.  
     
81.  
    tv.tv_sec=1;
82.  
    tv.tv_usec=0;
83.  
     
84.  
    while(1)
85.  
    {
86.  
    FD_ZERO(&select_fd);
87.  
    FD_SET(recv_sd,&select_fd);
88.  
     
89.  
    if(select(recv_sd 1,&select_fd,NULL,NULL,&tv)>0)
90.  
    {
91.  
    struct ip* ip;
92.  
    int hlen;
93.  
    int port;
94.  
     
95.  
     
96.  
    if(recvfrom(recv_sd,buff,MAXBUFF,0,NULL,NULL)!=56)
97.  
    {
98.  
    continue;
99.  
    }
100.  
      
101.  
     ip=(struct ip*)buff;
102.  
     hlen=ip->ip_hl<<2;
103.  
     icmp=(struct icmp*)(buff hlen);
104.  
      
105.  
     //取出接收到信息的端口号
106.  
     port=ntohs(*(u_short*)(buff 20 8 20 2));
107.  
      
108.  
     //icmp不能到达的包类型为3，检查IP地址以及初始端口号是否一致
109.  
     if((ip->ip_src.s_addr!=send_sa.sin_addr.s_addr)||(icmp->icmp_type!=ICMP_UNREACH)||(icmp->icmp_code!=ICMP_UNREACH_PORT)||(port!=dstport))
110.  
     continue;
111.  
     }
112.  
     else{
113.  
     struct servent *se;
114.  
     se=getservbyport(htons(dstport),"udp");
115.  
     printf("] %-20s \n",dstport,(se==NULL)?"unknown":se->s_name);
116.  
     }
117.  
     break;
118.  
     }
119.  
     }
120.  
     return EXIT_SUCCESS;
121.  
     }

运行结果

部分说明

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