simpleserver.c

一个LINUX下一个框架文件系统,运行编译环境：RED HAT LINUX7.3

#include "types.h"

#define SERVERPORT	6000
#define BACKLOG		10	//define pending queue length

int ServerSocket;  //Server Socket
struct sockaddr_in ServerAddress;

int insocket;  //in Socket
struct sockaddr_in inaddress;

void fatal( char * );
void server();
int path_get( char * fname, struct myfs_meta * pmeta );

void fatal( char *text )
{
  printf( "Error in %s\n", text );
  exit( 1 );
}

ssize_t readn(int fd, void * vptr, size_t n)
{
	ssize_t nleft;
	ssize_t nread;
	char * ptr;

	ptr 	= vptr;
	nleft 	= n;
	while(nleft > 0){
		if((nread = read(fd,ptr,nleft)) < 0){
			if(errno == EINTR)
				nread = 0;
			else
				return -1;
		}
		else
			if(nread == 0) break;
		nleft 	-= nread;
		ptr	+= nread;
	}
	return (n-nleft);
}

ssize_t writen(int fd, const void * vptr, size_t n)
{
	ssize_t nleft;
	ssize_t nwriten;
	const char * ptr;

	ptr 	= vptr;
	nleft	= n;
	while(nleft > 0){
		if( (nwriten = write(fd, ptr,nleft)) <= 0){
			if(errno == EINTR)
				nwriten = 0;
			else
				return -1;
		}
		nleft	-= nwriten;
		ptr	+= nwriten;
	}
	return n;
}
				
void server()
{
  int addrlen, length, counter;
  short optval;
  char  *SndBuffer, *RcvBuffer;
  
  if( (ServerSocket = socket(AF_INET, SOCK_STREAM, 0)) == -1 )
	fatal( "Create Socket.\n" );

  ServerAddress.sin_family = AF_INET;
  ServerAddress.sin_port = htons( SERVERPORT );
  ServerAddress.sin_addr.s_addr =htonl(INADDR_ANY);
  bzero( &( ServerAddress.sin_zero), 8 );

  addrlen = sizeof( ServerAddress );
  if( bind( ServerSocket, (struct sockaddr*)&ServerAddress, addrlen ) == -1 )
	fatal( "Server Binding.\n" );

  if( listen( ServerSocket, BACKLOG ) == -1 )
	fatal( "Server listening.\n" );
  printf("  listening the connection\n");

  while( 1 ){	//loop waiting
	addrlen = sizeof( ServerSocket );
  
	if( (insocket = accept( ServerSocket, &inaddress, &addrlen )) == -1 ){
		printf( "Accept Error!\n" );
		continue;
	}
	printf( "Get a connection from the other side!\n" );

	if( !fork() ){	//This is the child process in charge of the connection
		RcvBuffer = (char*) malloc( sizeof(struct outmessage) );
		SndBuffer = (char*) malloc( sizeof(struct inmessage) );

		if( readn( insocket, RcvBuffer, sizeof(struct outmessage)) == -1 ){
			printf( "Child process receive error!\n" );
			close( insocket );
			exit( 0 );
		}

		printf( "the directory is :%s\n", ((struct outmessage*)RcvBuffer)->dirname);
		((struct inmessage*)SndBuffer)->type = ((struct outmessage*)RcvBuffer)->type;
		if ( path_get( ((struct outmessage*)RcvBuffer)->dirname, 
						(struct myfs_meta*)&(((struct inmessage*)SndBuffer)->meta) ) <0 ){
			printf( "path_get failed!\n" );
		}


		if( writen( insocket, SndBuffer, sizeof(struct outmessage)) == -1 ){
			printf( "Child process send error!\n" );
			close( insocket );
			exit( 0 );
		}
		free (RcvBuffer);
		free (SndBuffer);
		close( insocket );	//parent do not need this
		exit(0);
	}//child process
  } //while
}

int path_get( char * fname, struct myfs_meta * pmeta )
{
	struct stat filestat;
	int fd, len, is_dir = 0;
	char nbuf[MAXPATHLEN];
	char tmpbuf[4096];

/*	// strip off any trailing /'s on the file name
	for (len = strlen(nbuf); len > 0 && nbuf[len] == '/'; nbuf[len--] = '\0');
	if (len < 0) return(-1);

	if (stat(nbuf, &filestat) < 0 || !S_ISDIR(filestat.st_mode)) {
		printf( "The file %s is not a directory.\n", nbuf );
	}

	is_dir = 1;

	if ((fd = open(nbuf, O_RDONLY, 0)) < 0) return -1;
	lseek(fd, 0, SEEK_SET);
	if (read(fd, tmpbuf, 4096) < 0) return -1;

	// read the set values out of the file 
	pmeta->handle  = strtol(strtok(tmpbuf, "\n"), NULL, 10);
	pmeta->uid  = strtol(strtok(NULL, "\n"), NULL, 10);
	pmeta->uid  = strtol(strtok(NULL, "\n"), NULL, 10);
	pmeta->mode = strtol(strtok(NULL, "\n"), NULL, 8);
	pmeta->valid = strtol(strtok(NULL, "\n"), NULL, 10);

	close(fd);
*/
	//my modifications	some what artificial!
	pmeta->handle  = 0x5a305;
	pmeta->uid  = 0;
	pmeta->uid  = 0;
	pmeta->mode = 0x41ff;
	pmeta->valid = 0x77;
	return 0;
}

main( void )
{
  server();
  return 0;
}