情報工学実験２「ＴＣＰ／ＩＰプログラミング」

a-1.プログラム

#include <stdio.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <string.h>
#include <ctype.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdlib.h>


#define DATAFILE "data.txt"
#define DELIMITS " \t\n\r"

char datavalue[256];

int GetLineFromPeer(char *line, int hostsoc)
{
  int i;

  for(i = 0 ; ; )
    {
      if(1 != read(hostsoc,line + i,1))
continue;
      else
{
  i++;
  *(line + i) = (char)0;
}

      if(((char)('\n')) == (*(line + i - 1)))
return i;
    }
}

char *GetKeywordData(char *key)
{
  FILE*fp;
  char buff[256];

  if((FILE *)NULL == (fp = fopen(DATAFILE,"r")))
    return (char *)NULL;

  for(;;)
    {
      char*p;
      char*pp;

      fgets(buff,256,fp);

      if(feof(fp))
break;

      if(ferror(fp))
break;

      if((char *)NULL == (p = strtok(buff,DELIMITS)))
continue;

      if((char *)NULL == (pp = strtok((char *)NULL,DELIMITS)))
continue;

      if(0 == strcmp(p,key))
{
  fclose(fp);
  strcpy(datavalue,pp);
  return datavalue;
}
    }

  fclose(fp);
  return (char *)NULL;
}

int main()
{

  /**********deamon********/
  unsigned short port = 5683;
  int servsoc; 
  int hostsoc;
  
  struct sockaddr_in srcAddr;
  struct sockaddr_in dstAddr;
  int dstAddrSize = sizeof(dstAddr);
  
  memset(&srcAddr, 0, sizeof(srcAddr));
  srcAddr.sin_port = htons(port);
  srcAddr.sin_family = AF_INET;
  srcAddr.sin_addr.s_addr = htonl(INADDR_ANY);

  servsoc = socket(AF_INET, SOCK_STREAM, 0);
   
  bind(servsoc, (struct sockaddr *) &srcAddr, sizeof(srcAddr));

  listen(servsoc, 1);
  
  printf("now waiting for client connect\n");
  
  hostsoc = accept(servsoc, (struct sockaddr *) &dstAddr, &dstAddrSize);
  printf("Connected from %s\n", inet_ntoa(dstAddr.sin_addr));

  /**********daemon-ed**********/

  char RecvBuff[256];

  for(;;)
    {
      char*p;
      char SendBuff[256];
      char*pp;

      (void)GetLineFromPeer(RecvBuff, hostsoc);/* Get 1 line from peer */
      

      if(((char)('=')) == *(RecvBuff))/* If End Mark */
{
  close(0);
  exit(0);
}

      if((char *)NULL != (p = strchr(RecvBuff,'=')))
{
  *p = (char)0;

  if((char *)NULL == (pp = GetKeywordData(RecvBuff)))
    sprintf(SendBuff,"%s=\n",RecvBuff);
  else
    sprintf(SendBuff,"%s=%s\n",RecvBuff,pp);

  (void)write(hostsoc,SendBuff,strlen(SendBuff));
}
    }
}

a-2.プログラム

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

		  #defineSERVICE_NAME"tcpinetd"
		  #definePROTOCOL"tcp"
		  #defineHOST_NAME"localhost"

		  intConnect()
{
		  intSocketNumber;/* Socket descripter */
		  structservent*ServiceEntry;/* service entry */
		  structhostent*HostEntry;/* host entry */
		  structsockaddr_insin;/* Socket Entry */

/* Get Service Entry by Service-Name */

/******
 * if((struct servent *)NULL == (ServiceEntry =
		  *getservbyname(SERVICE_NAME,PROTOCOL)))
 *
 * {
 * printf("\7No service [%s].\n",SERVICE_NAME);
 * exit(1);
 * }
 * printf("%d\n",ServiceEntry->s_port);
 *****/

/* Get Host Entry by Host-Name */

/**********
 *if((struct hostent *)NULL == (HostEntry = gethostbyname(HOST_NAME)))
		  *{
		  *printf("\7No Hosts [%s].\n",HOST_NAME);
		  *exit(1);
		  *}
 *********/

/* Get Socket */

/******deamon*******/

HostEntry = gethostbyname("localhost");
  if(!HostEntry){
    printf("error:failed to serch the host\n");
    exit(1);
  }

/******deamon-ed******/

if(0 > (SocketNumber = (socket(AF_INET,SOCK_STREAM,0))))
		  {
		  printf("\7Cannot get Socket.\n");
		  perror("\n");
		  exit(1);
		  }

/* Set protocol family name */
sin.sin_family = AF_INET;

/* Set Host Address */
bcopy(HostEntry->h_addr,&sin.sin_addr,HostEntry->h_length);

/* Set Port N.o. */
 sin.sin_port = 5683;  //ServiceEntry->s_port;

if(0 > connect(SocketNumber,(struct sockaddr *)(&sin),sizeof(sin)))
		  {
		  printf("\7Cannot Connect.\n");
		  perror("\n");
		  exit(1);
		  }

return SocketNumber;
}

		  voidDisconnect(int SocketNumber)
{
close(SocketNumber);
}

		  voidSendData(int SocketNumber,char *line)
{
if(strlen(line) != write(SocketNumber,line,strlen(line)))
		  {
		  printf("\7Send Failed.\n");
		  exit(1);
		  }
}

		  intRecvData(int SocketNumber,char *line)
{
		  inti;

for(i = 0 ;;)
		  {
		  if(1 != read(SocketNumber,line + i,1))
		  continue;
		  else
		  {
		  i++;
		  *(line + i) = (char)0;
		  
		  if(((char)('\n')) == *(line + i - 1))
		  return i;
		  }
		  }
}

		  intmain()
{
		  intSock;
		  charKey[256];
		  charData[256];
		  charbuff[256];

		  Sock = Connect();/* Connect */
printf("Connected.\n");

for(;;)
		  {
		  char*p;

		  printf("Input Keyword = ");
		  fflush(stdout);

		  gets(Key);
		  sprintf(buff,"%s=\n",Key);
		  SendData(Sock,buff);/* Send It ! */

		  if(0 == strlen(Key))
		  break;/* If End Mark */

		  /* ---- Waiting for Server response Here --- */

		  (void)RecvData(Sock,buff);/* Recv It ! */

		  if((char *)NULL != (p = strchr(buff,'\n')))
		  *p = (char)0;

		  if((char *)NULL != (p = strchr(buff,'=')))
		  p++;

		  printf("Keyword = [%s] / Data = [%s]\n\n",Key,p);
		  }

		  Disconnect(Sock);/* Disconnect */
printf("Disocnnected.\n");
}

b.実行結果

*[nw0538:~]*(^_^)v j05038% ./a-2
Connected.
Input Keyword = warning: this program uses gets(), which is unsafe.
yama
Keyword = [yama] / Data = [kawa]

Input Keyword = xyz
Keyword = [xyz] / Data = [XYZ]

Input Keyword = 123
Keyword = [123] / Data = [456]

Input Keyword = xxxx
Keyword = [xxxx] / Data = [yyyy]

Input Keyword = shiro
Keyword = [shiro] / Data = [kuro]

Input Keyword = ^X^C
*[nw0538:~]*(^_^)v j05038% 
 

考察