求LINUX下的端口扫描程序
使用Socket API，接受IP 地址，输出该IP 地址对应的主机所支持的<端口号, 协议(TCP/UDP), 服务名[3]>
[解决办法]
开源的 nmap ...
[解决办法]
以前调试过一个，发个你看下吧。
其实道理不难，就是发送icmp包，跟ping类似，然后等待回应，若超时或者无响应则判断端口未开。
主机扫描的也类似。
#include<stdio.h>#include<stdlib.h>#include<string.h>#include<math.h>#include<netdb.h>#include<unistd.h>#include<sys/time.h>#include<sys/types.h>#include<sys/socket.h>#include<netinet/in_systm.h>#include<netinet/in.h>#include<netinet/ip.h>#include<netinet/ip_icmp.h>#include<arpa/inet.h>#include <time.h>/*#define CHKADDRESS( _saddr_){ u_char *p =(char *)&(_saddr_); if( (p[0] == 10) || (p[0] ==168 &&16<=p[1]&&p[1]<=31) ||(p[0] ==192 && p[1]==168) {} else { fprintf(stderr,"IP address error.\n"); exit(EXIT_FAILURE); }}*/enum {CMD_NAME,DST_IP,START_PORT,LAST_PORT};#define MAXBUFF 8192int main(int argc,char *argv[]){ clock_t start, finish; struct icmp *icmp; fd_set select_fd; struct sockaddr_in send_sa; int recv_sd; int send_sd; char buff[MAXBUFF]; int endport; int startport; int dstport; struct timeval tv; struct ip *ip; int hlen,port; int count; if(argc!=4) { fprintf(stderr," usge:%s dst_ip start_port last_port\n",argv[CMD_NAME]); exit(EXIT_FAILURE); } send_sa.sin_family = AF_INET; send_sa.sin_addr.s_addr = inet_addr(argv[DST_IP]); startport = atoi(argv[START_PORT]); endport = atoi(argv[LAST_PORT]); //CHKADDRESS(send_sa.sin_addr.s_addr); if( (send_sd = socket(AF_INET,SOCK_DGRAM,0))<0) { perror(" socket (SOCK_DGRAM)"); exit(EXIT_FAILURE); } if( (recv_sd = socket(AF_INET,SOCK_RAW,IPPROTO_ICMP))<0) { perror(" socket (SOCK_RAW)"); exit(EXIT_FAILURE); } for(dstport = startport;dstport<=endport;dstport++) { printf(" Scan port %d: %d times\r",dstport,count); fflush(stdout); send_sa.sin_port = htons (dstport); sendto(send_sd,NULL,0,0,(void *) &send_sa,sizeof(send_sa)); tv.tv_sec=1; tv.tv_usec=0; count=0; //记录每次同一端口,ICMP包数量 start = clock(); while(1) { FD_ZERO(&select_fd); FD_SET(recv_sd,&select_fd); if(select (recv_sd+1,&select_fd,NULL,NULL,&tv)>0) if(recvfrom(recv_sd,buff,MAXBUFF,0,NULL,NULL)!=56) //ICMP包,长度为56,IP+ICMP+IP+UDP continue; //intf("a new icmp ack\n"); if( ((finish=clock() )-start)>=2) { printf("2 sec no target icmp ack.\n"); struct servent *se_t; se_t=getservbyport(htons (dstport)," udp"); printf("%5d %-20s\n",dstport,(se_t==NULL)?"unkown":se_t->s_name); break; } ip=(struct ip *)buff; hlen=ip->ip_hl<<2; icmp=(struct icmp *)(buff+hlen); port=ntohs(* (u_short *)(buff+20+8+20+2) ); 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)) { if(count>10) { printf("port %d:icmp_type is %d;icmp_code is %d.\n",port,icmp->icmp_type,icmp->icmp_code); break; } if(ip->ip_src.s_addr==send_sa.sin_addr.s_addr && port==dstport) { //printf(" %d times\r",count); count++; break; } //printf("Not target icmp packet.continue check port %d\n",dstport); continue; } else { struct servent *se; se=getservbyport(htons (dstport)," udp"); //if(se!=NULL) printf("%5d %-20s\n",dstport,(se==NULL)?"unkown":se->s_name); } break; } } return EXIT_SUCCESS;}
[解决办法]
[root@RHEL4_U5 ~]# netstat -a
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 *:ftp *:* LISTEN
tcp 0 0 *:ssh *:* LISTEN
getnameinfo failed
getnameinfo failed
tcp 0 0 [UNKNOWN]:ssh [UNKNOWN]:2341 ESTABLISHED
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node Path
unix 4 [ ] DGRAM 5684 /dev/log
unix 2 [ ACC ] STREAM LISTENING 5895 /var/run/acpid.socket
unix 2 [ ACC ] STREAM LISTENING 6133 /tmp/.font-unix/fs7100
unix 2 [ ACC ] STREAM LISTENING 6106 /var/run/iiim/.iiimp-unix/9010
unix 2 [ ACC ] STREAM LISTENING 6169 /var/run/dbus/system_bus_socket
unix 2 [ ] DGRAM 6358 @/var/run/hal/hotplug_socket
unix 2 [ ] DGRAM 3840 @udevd
unix 2 [ ] DGRAM 14405
unix 3 [ ] STREAM CONNECTED 6357 /var/run/dbus/system_bus_socket
unix 3 [ ] STREAM CONNECTED 6356
unix 3 [ ] STREAM CONNECTED 6177
unix 3 [ ] STREAM CONNECTED 6176
unix 2 [ ] DGRAM 6028
unix 3 [ ] STREAM CONNECTED 5795
unix 3 [ ] STREAM CONNECTED 5794
unix 2 [ ] DGRAM 5703
[root@RHEL4_U5 ~]#