假设要判断某台机器打开了哪些tcp端口 该如何设计端口扫描程序
直接在命令提示符里面输入 netstat -a 就可以了。
netstat -a 查看开启了哪些端口,常用netstat -a
netstat -n 查看端口的网络连接情况,常用netstat -an
linux下用C写的一个端口扫描器,想得到扫描主机的操作系统类型
nmap 命令行
zenmap 图形化界面
一般能扫描出主机的操作系统版本
100分求linux下C语言端口扫描代码
linux tcp udp 端口扫描源程序
#include sys/socket.h
#include netinet/in.h
#include arpa/inet.h
#include unistd.h
#include errno.h
#include netdb.h
#include stdio.h
#include string.h
#include netinet/ip_icmp.h
#include stdlib.h
#include signal.h
#include libxml/parser.h
#include libxml/tree.h
#define TRUE 1
#define FALSE 0
#define UDP "UDP"
#define TCP "TCP"
#define tcp "tcp"
#define udp "udp"
typedef struct _GsSockStru{
int fd;
int len;
struct sockaddr_in addr;
}GsSockStru;
static int tcptest( char ip[32], char port[20]);
static int udptest( char ip[32], char port[20]);
void sig_alrm( int signo );
static GsSockStru test_sock;
int
main( int argc, char** argv)
{
char string[64];
char port[20];
char pro[20];
char ip[32];
int res;
int i = 0;
int k = 0;
if( argc2 || argc2 )
{
printf("鍙傛暟涓嶆纭?-1\n");
return ( -1 );
}
strcpy( string, argv[1]);
while( *string )
{
if( string[i] == ':' )
break;
pro[k] = string[i];
k++;
i++;
}
pro[k] = '\0';
i++;
k = 0;
while( *string )
{
if( string[i] == ':')
break;
ip[k] = string[i];
k++;
i++;
}
ip[k] = '\0';
i++;
k=0;
while( *string )
{
if( string[i] == '\0')
break;
port[k] = string[i];
k++;
i++;
}
port[k] = '\0';
i++;
memset( test_sock, 0, sizeof( test_sock ) );
if ( ( strcmp( TCP, pro) != 0 ) ( strcmp( UDP, pro) != 0 ) ( strcmp( tcp, pro) != 0 ) ( strcmp( udp, pro) != 0 ))
{
printf ( "鍙傛暟涓嶆纭?锛?\n" );
return (-1);
}
if ( strcmp( TCP, pro) == 0 || strcmp( tcp, pro) == 0 )
res = tcptest( ip, port );
if ( strcmp( UDP, pro) == 0 || strcmp( udp, pro) == 0 )
res = udptest( ip, port );printf("%d\n",res);
return ( res );
}
int
tcptest( char ip[32], char port[20])
{
int res;
struct timeval tv;
test_sock.fd = socket( AF_INET, SOCK_STREAM, 0 );
if ( test_sock.fd 0 )
{
printf( "create socket failed -3 \n" );
return ( -3 );
}
memset( ( test_sock.addr ), 0, sizeof( test_sock.addr ) );
test_sock.addr.sin_family = AF_INET;
test_sock.addr.sin_port = htons( atoi( port ) );
inet_pton( AF_INET, ip, test_sock.addr.sin_addr );
test_sock.len = sizeof( struct sockaddr );
tv.tv_sec = 10;
tv.tv_usec = 0;
setsockopt( test_sock.fd, SOL_SOCKET, SO_RCVTIMEO,
(const char *)tv, sizeof( tv ) );
res = connect( test_sock.fd,
( struct sockaddr * )( ( test_sock.addr ) ),
test_sock.len );
if ( res 0 )
{
fprintf( stderr, "connect failed 0\n" );
close( test_sock.fd );
return FALSE;
}
close( test_sock.fd );
return TRUE;
}
int udptest( char ip[32], char port[20])
{
struct icmphdr *icmp_header;
struct sockaddr_in target_info;
int target_info_len;
fd_set read_fd;
int scan_port;
char recvbuf[5000];
struct sockaddr_in target_addr;
int icmp_socket;
int udp_socket;
struct timeval tv;
icmp_header = (struct icmphdr *)(recvbuf+sizeof(struct iphdr));
scan_port = atoi( port );
target_addr.sin_family = AF_INET;
inet_pton( AF_INET, ip, target_addr.sin_addr );
target_addr.sin_port = htons(scan_port);
if ((udp_socket=socket(AF_INET,SOCK_DGRAM,0))==-1)
{
printf("create socket failed -3\n");
return -3;
}
if ((icmp_socket=socket(AF_INET,SOCK_RAW,IPPROTO_ICMP))==-1)
{
printf("Create raw socket failed -3\n");
return -3;
}
sendto(udp_socket,NULL,0,0,(void *)target_addr,sizeof(target_addr));
FD_ZERO(read_fd);
FD_SET(icmp_socket,read_fd);
tv.tv_sec = 1;
tv.tv_usec = 0;
select(FD_SETSIZE,read_fd,NULL,NULL,tv);
for (;;){
if (FD_ISSET(icmp_socket,read_fd))
{
target_info_len = sizeof(target_info);
recvfrom(icmp_socket,recvbuf,5000,0,
(struct sockaddr *)target_info,target_info_len);
if (target_info.sin_addr.s_addr == target_addr.sin_addr.s_addr
icmp_header-type == 3 icmp_header-code=12)
{
printf("Port %d : Close\n",scan_port);
return (0);
}
}
return (1) ;
}
}
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