Full Code of beckysag/ftp for AI

Repository: beckysag/ftp
Branch: master
Commit: 7fc6696c4b6f
Files: 11
Total size: 21.9 KB

Directory structure:
gitextract_3_b0db68/

├── README.md
├── client/
│   ├── ftclient.c
│   ├── ftclient.h
│   └── makefile
├── common/
│   ├── common.c
│   └── common.h
└── server/
    ├── .auth
    ├── .auth~
    ├── ftserve.c
    ├── ftserve.h
    └── makefile

================================================
FILE CONTENTS
================================================

================================================
FILE: README.md
================================================
FTP Client-Server Implementation
===========
Simple implementation of a file transfer program. It includes custom client and server programs that provide functionality to authenticate a user, list remote files, and retrieve remote files.

### Directory layout:
	ftp/
		client/
			ftclient.c
			ftclient.h
			makefile
		common/
			common.c
			common.h
		server/
			ftserve.c
			ftserve.h
			makefile
			.auth

###Usage
To compile and link ftserve:
```
	$ cd server/
	$ make
```

To compile and link ftclient:
```
	$ cd client/
	$ make
```

To run ftserve:
```
	$ server/ftserve PORTNO
```

To run ftclient:
```
	$ client/ftclient HOSTNAME PORTNO

	Commands:
		list
		get <filename>
		quit
```

Available commands:
```
list            - retrieve list of files in the current remote directory
get <filename>  - get the specified file
quit            - end the ftp session
```

Logging In:
```
	Name: anonymous
	Password: [empty]
```


================================================
FILE: client/ftclient.c
================================================
#include "ftclient.h"
	

int sock_control; 


/**
 * Receive a response from server
 * Returns -1 on error, return code on success
 */
int read_reply(){
	int retcode = 0;
	if (recv(sock_control, &retcode, sizeof retcode, 0) < 0) {
		perror("client: error reading message from server\n");
		return -1;
	}	
	return ntohl(retcode);
}



/**
 * Print response message
 */
void print_reply(int rc) 
{
	switch (rc) {
		case 220:
			printf("220 Welcome, server ready.\n");
			break;
		case 221:
			printf("221 Goodbye!\n");
			break;
		case 226:
			printf("226 Closing data connection. Requested file action successful.\n");
			break;
		case 550:
			printf("550 Requested action not taken. File unavailable.\n");
			break;
	}
	
}


/**
 * Parse command in cstruct
 */ 
int ftclient_read_command(char* buf, int size, struct command *cstruct)
{
	memset(cstruct->code, 0, sizeof(cstruct->code));
	memset(cstruct->arg, 0, sizeof(cstruct->arg));
	
	printf("ftclient> ");	// prompt for input		
	fflush(stdout); 	

	// wait for user to enter a command
	read_input(buf, size);
		
	char *arg = NULL;
	arg = strtok (buf," ");
	arg = strtok (NULL, " ");

	if (arg != NULL){
		// store the argument if there is one
		strncpy(cstruct->arg, arg, strlen(arg));
	}

	// buf = command
	if (strcmp(buf, "list") == 0) {
		strcpy(cstruct->code, "LIST");		
	}
	else if (strcmp(buf, "get") == 0) {
		strcpy(cstruct->code, "RETR");		
	}
	else if (strcmp(buf, "quit") == 0) {
		strcpy(cstruct->code, "QUIT");		
	}
	else {//invalid
		return -1;
	}

	// store code in beginning of buffer
	memset(buf, 0, 400);
	strcpy(buf, cstruct->code);

	// if there's an arg, append it to the buffer
	if (arg != NULL) {
		strcat(buf, " ");
		strncat(buf, cstruct->arg, strlen(cstruct->arg));
	}
	
	return 0;
}



/**
 * Do get <filename> command 
 */
int ftclient_get(int data_sock, int sock_control, char* arg)
{
    char data[MAXSIZE];
    int size;
    FILE* fd = fopen(arg, "w");
    
    while ((size = recv(data_sock, data, MAXSIZE, 0)) > 0) {
        fwrite(data, 1, size, fd);
    }

    if (size < 0) {
        perror("error\n");
    }

    fclose(fd);
    return 0;
}


/**
 * Open data connection
 */
int ftclient_open_conn(int sock_con)
{
	int sock_listen = socket_create(CLIENT_PORT_ID);

	// send an ACK on control conn
	int ack = 1;
	if ((send(sock_con, (char*) &ack, sizeof(ack), 0)) < 0) {
		printf("client: ack write error :%d\n", errno);
		exit(1);
	}		

	int sock_conn = socket_accept(sock_listen);
	close(sock_listen);
	return sock_conn;
}




/** 
 * Do list commmand
 */
int ftclient_list(int sock_data, int sock_con)
{
	size_t num_recvd;			// number of bytes received with recv()
	char buf[MAXSIZE];			// hold a filename received from server
	int tmp = 0;

	// Wait for server starting message
	if (recv(sock_con, &tmp, sizeof tmp, 0) < 0) {
		perror("client: error reading message from server\n");
		return -1;
	}
	
	memset(buf, 0, sizeof(buf));
	while ((num_recvd = recv(sock_data, buf, MAXSIZE, 0)) > 0) {
        	printf("%s", buf);
		memset(buf, 0, sizeof(buf));
	}
	
	if (num_recvd < 0) {
	        perror("error");
	}

	// Wait for server done message
	if (recv(sock_con, &tmp, sizeof tmp, 0) < 0) {
		perror("client: error reading message from server\n");
		return -1;
	}
	return 0;
}



/**
 * Input: cmd struct with an a code and an arg
 * Concats code + arg into a string and sends to server
 */
int ftclient_send_cmd(struct command *cmd)
{
	char buffer[MAXSIZE];
	int rc;

	sprintf(buffer, "%s %s", cmd->code, cmd->arg);
	
	// Send command string to server
	rc = send(sock_control, buffer, (int)strlen(buffer), 0);	
	if (rc < 0) {
		perror("Error sending command to server");
		return -1;
	}
	
	return 0;
}



/**
 * Get login details from user and
 * send to server for authentication
 */
void ftclient_login()
{
	struct command cmd;
	char user[256];
	memset(user, 0, 256);

	// Get username from user
	printf("Name: ");	
	fflush(stdout); 		
	read_input(user, 256);

	// Send USER command to server
	strcpy(cmd.code, "USER");
	strcpy(cmd.arg, user);
	ftclient_send_cmd(&cmd);
	
	// Wait for go-ahead to send password
	int wait;
	recv(sock_control, &wait, sizeof wait, 0);

	// Get password from user
	fflush(stdout);	
	char *pass = getpass("Password: ");	

	// Send PASS command to server
	strcpy(cmd.code, "PASS");
	strcpy(cmd.arg, pass);
	ftclient_send_cmd(&cmd);
	
	// wait for response
	int retcode = read_reply();
	switch (retcode) {
		case 430:
			printf("Invalid username/password.\n");
			exit(0);
		case 230:
			printf("Successful login.\n");
			break;
		default:
			perror("error reading message from server");
			exit(1);		
			break;
	}
}





int main(int argc, char* argv[]) 
{		
	int data_sock, retcode, s;
	char buffer[MAXSIZE];
	struct command cmd;	
	struct addrinfo hints, *res, *rp;

	if (argc != 3) {
		printf("usage: ./ftclient hostname port\n");
		exit(0);
	}

	char *host = argv[1];
	char *port = argv[2];

	// Get matching addresses
	memset(&hints, 0, sizeof(struct addrinfo));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	
	s = getaddrinfo(host, port, &hints, &res);
	if (s != 0) {
		printf("getaddrinfo() error %s", gai_strerror(s));
		exit(1);
	}
	
	// Find an address to connect to & connect
	for (rp = res; rp != NULL; rp = rp->ai_next) {
		sock_control = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);

		if (sock_control < 0)
			continue;

		if(connect(sock_control, res->ai_addr, res->ai_addrlen)==0) {
			break;
		} else {
			perror("connecting stream socket");
			exit(1);
		}
		close(sock_control);
	}
	freeaddrinfo(rp);


	// Get connection, welcome messages
	printf("Connected to %s.\n", host);
	print_reply(read_reply()); 
	

	/* Get name and password and send to server */
	ftclient_login();

	while (1) { // loop until user types quit

		// Get a command from user
		if ( ftclient_read_command(buffer, sizeof buffer, &cmd) < 0) {
			printf("Invalid command\n");
			continue;	// loop back for another command
		}

		// Send command to server
		if (send(sock_control, buffer, (int)strlen(buffer), 0) < 0 ) {
			close(sock_control);
			exit(1);
		}

		retcode = read_reply();		
		if (retcode == 221) {
			/* If command was quit, just exit */
			print_reply(221);		
			break;
		}
		
		if (retcode == 502) {
			// If invalid command, show error message
			printf("%d Invalid command.\n", retcode);
		} else {			
			// Command is valid (RC = 200), process command
		
			// open data connection
			if ((data_sock = ftclient_open_conn(sock_control)) < 0) {
				perror("Error opening socket for data connection");
				exit(1);
			}			
			
			// execute command
			if (strcmp(cmd.code, "LIST") == 0) {
				ftclient_list(data_sock, sock_control);
			} 
			else if (strcmp(cmd.code, "RETR") == 0) {
				// wait for reply (is file valid)
				if (read_reply() == 550) {
					print_reply(550);		
					close(data_sock);
					continue; 
				}
				ftclient_get(data_sock, sock_control, cmd.arg);
				print_reply(read_reply()); 
			}
			close(data_sock);
		}

	} // loop back to get more user input

	// Close the socket (control connection)
	close(sock_control);
    return 0;  
}


================================================
FILE: client/ftclient.h
================================================
/* ftclient.h
 *
 * Rebecca Sagalyn
 * 11/15/13
 *
 * Client side of TCP file transfer implementation, runs with custom server, 
 * ftserve.c. Receives commands from input, and retreives list of files in current 
 * and files. 
   * 
 * Valid commands: 
 *    get <filename>
 *    list
 *    quit
 *    
 * Usage: 
 *    ./ftclient SERVER_HOSTNAME PORT#
 */

#ifndef FTCLIENT_H
#define FTCLIENT_H

#include "../common/common.h"


/**
 * Receive a response from server
 * Returns -1 on error, return code on success
 */
int read_reply();


/**
 * Print response message
 */
void print_reply(int rc);


/**
 * Parse command in cstruct
 */ 
int ftclient_read_command(char* buf, int size, struct command *cstruct);


/**
 * Do get <filename> command 
 */
int ftclient_get(int data_sock, int sock_control, char* arg);


/**
 * Open data connection
 */
int ftclient_open_conn(int sock_con);


/** 
 * Do list commmand
 */
int ftclient_list(int sock_data, int sock_con);


/**
 * Input: cmd struct with an a code and an arg
 * Concats code + arg into a string and sends to server
 */
int ftclient_send_cmd(struct command *cmd);


/**
 * Get login details from user and
 * send to server for authentication
 */
void ftclient_login();


#endif


================================================
FILE: client/makefile
================================================
CC := gcc
CFLAGS := -Wall -g -Os

SHDIR := ../common

OBJS = ftclient.o $(SHDIR)/common.o

all: ftclient

ftclient: $(OBJS)
	@$(CC) -o ftclient $(CFLAGS) $(OBJS)

$(OBJS) : %.o: %.c 
	@$(CC) -c $(CFLAGS) $< -o $@

.PHONY:
clean:
	@rm -f *.o ftclient
	@rm -f ../common/*.o
	@echo Done cleaning


================================================
FILE: common/common.c
================================================
#include "common.h"


/**
 * Create listening socket on remote host
 * Returns -1 on error, socket fd on success
 */
int socket_create(int port)
{
	int sockfd;
	int yes = 1;
	struct sockaddr_in sock_addr;

	// create new socket
	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		perror("socket() error"); 
		return -1; 
	}

	// set local address info
	sock_addr.sin_family = AF_INET;
	sock_addr.sin_port = htons(port);
	sock_addr.sin_addr.s_addr = htonl(INADDR_ANY);		

	if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1) {
		close(sockfd);
		perror("setsockopt() error");
		return -1; 
	}

	// bind
	if (bind(sockfd, (struct sockaddr *) &sock_addr, sizeof(sock_addr)) < 0) {
		close(sockfd);
		perror("bind() error"); 
		return -1; 
	}
   
	// begin listening for incoming TCP requests
	if (listen(sockfd, 5) < 0) {
		close(sockfd);
		perror("listen() error");
		return -1;
	}              
	return sockfd;
}





/**
 * Create new socket for incoming client connection request
 * Returns -1 on error, or fd of newly created socket
 */
int socket_accept(int sock_listen)
{
	int sockfd;
	struct sockaddr_in client_addr;
	socklen_t len = sizeof(client_addr);

	// Wait for incoming request, store client info in client_addr
	sockfd = accept(sock_listen, (struct sockaddr *) &client_addr, &len);
	
	if (sockfd < 0) {
		perror("accept() error"); 
		return -1; 
	}
	return sockfd;
}




/**
 * Connect to remote host at given port
 * Returns:	socket fd on success, -1 on error
 */
int socket_connect(int port, char*host)
{
	int sockfd;  					
	struct sockaddr_in dest_addr;

	// create socket
	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) { 
        	perror("error creating socket");
        	return -1;
    }

	// create server address
	memset(&dest_addr, 0, sizeof(dest_addr));
	dest_addr.sin_family = AF_INET;
	dest_addr.sin_port = htons(port);
	dest_addr.sin_addr.s_addr = inet_addr(host);

	// Connect on socket
	if(connect(sockfd, (struct sockaddr *)&dest_addr, sizeof(dest_addr)) < 0 ) {
        	perror("error connecting to server");
		return -1;
    	}    
	return sockfd;
}



/**
 * Receive data on sockfd
 * Returns -1 on error, number of bytes received 
 * on success
 */
int recv_data(int sockfd, char* buf, int bufsize){
	size_t num_bytes;
	memset(buf, 0, bufsize);
	num_bytes = recv(sockfd, buf, bufsize, 0);
	if (num_bytes < 0) {
		return -1;
	}
	return num_bytes;
}




/**
 * Trim whiteshpace and line ending
 * characters from a string
 */
void trimstr(char *str, int n)
{
	int i;
	for (i = 0; i < n; i++) {
		if (isspace(str[i])) str[i] = 0;
		if (str[i] == '\n') str[i] = 0;
	}
}


/**
 * Send resposne code on sockfd
 * Returns -1 on error, 0 on success
 */
int send_response(int sockfd, int rc)
{
	int conv = htonl(rc);
	if (send(sockfd, &conv, sizeof conv, 0) < 0 ) {
		perror("error sending...\n");
		return -1;
	}
	return 0;
}




/** 
 * Read input from command line
 */
void read_input(char* buffer, int size)
{
	char *nl = NULL;
	memset(buffer, 0, size);

	if ( fgets(buffer, size, stdin) != NULL ) {
		nl = strchr(buffer, '\n');
		if (nl) *nl = '\0'; // truncate, ovewriting newline
	}
}




================================================
FILE: common/common.h
================================================
#ifndef COMMON_H
#define COMMON_H

#include <arpa/inet.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>		// getaddrinfo()
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>



/* constants */
#define DEBUG				1
#define MAXSIZE 			512 	// max buffer size
#define CLIENT_PORT_ID		30020


/* Holds command code and argument */
struct command {
	char arg[255];
	char code[5];
};




/**
 * Create listening socket on remote host
 * Returns -1 on error, socket fd on success
 */
int socket_create(int port);


/**
 * Create new socket for incoming client connection request
 * Returns -1 on error, or fd of newly created socket
 */
int socket_accept(int sock_listen);


/**
 * Connect to remote host at given port
 * Returns socket fd on success, -1 on error
 */
int socket_connect(int port, char *host);



/**
 * Receive data on sockfd
 * Returns -1 on error, number of bytes received 
 * on success
 */
int recv_data(int sockfd, char* buf, int bufsize);


/**
 * Send resposne code on sockfd
 * Returns -1 on error, 0 on success
 */
int send_response(int sockfd, int rc);



//------------------- UTILITY FUNCTIONS-------------------//

/**
 * Trim whiteshpace and line ending
 * characters from a string
 */
void trimstr(char *str, int n);



/** 
 * Read input from command line
 */
void read_input(char* buffer, int size);


#endif









================================================
FILE: server/.auth
================================================
user pass
test testpass
anonymous 


================================================
FILE: server/.auth~
================================================
user pass
test testpass


================================================
FILE: server/ftserve.c
================================================
#include "ftserve.h"


int main(int argc, char *argv[])
{	
	int sock_listen, sock_control, port, pid;

	if (argc != 2) {
		printf("usage: ./ftserve port\n");
		exit(0);
	}

	port = atoi(argv[1]);

	// create socket
	if ((sock_listen = socket_create(port)) < 0 ) {
		perror("Error creating socket");
		exit(1);
	}		
	
	while(1) {	// wait for client request

		// create new socket for control connection
		if ((sock_control = socket_accept(sock_listen))	< 0 )
			break;			
		
		// create child process to do actual file transfer
		if ((pid = fork()) < 0) { 
			perror("Error forking child process");
		} else if (pid == 0) { 
			close(sock_listen);
			ftserve_process(sock_control);		
			close(sock_control);
			exit(0);
		}
			
		close(sock_control);
	}

	close(sock_listen);	

	return 0;
}



/**
 * Send file specified in filename over data connection, sending
 * control message over control connection
 * Handles case of null or invalid filename
 */
void ftserve_retr(int sock_control, int sock_data, char* filename)
{	
	FILE* fd = NULL;
	char data[MAXSIZE];
	size_t num_read;							
		
	fd = fopen(filename, "r");
	
	if (!fd) {	
		// send error code (550 Requested action not taken)
		send_response(sock_control, 550);
		
	} else {	
		// send okay (150 File status okay)
		send_response(sock_control, 150);
	
		do {
			num_read = fread(data, 1, MAXSIZE, fd);

			if (num_read < 0) {
				printf("error in fread()\n");
			}

			// send block
			if (send(sock_data, data, num_read, 0) < 0)
				perror("error sending file\n");

		} while (num_read > 0);													
			
		// send message: 226: closing conn, file transfer successful
		send_response(sock_control, 226);

		fclose(fd);
	}
}





/**
 * Send list of files in current directory
 * over data connection
 * Return -1 on error, 0 on success
 */
int ftserve_list(int sock_data, int sock_control)
{
	char data[MAXSIZE];
	size_t num_read;									
	FILE* fd;

	int rs = system("ls -l | tail -n+2 > tmp.txt");
	if ( rs < 0) {
		exit(1);
	}
	
	fd = fopen("tmp.txt", "r");	
	if (!fd) {
		exit(1);
	}

	/* Seek to the beginning of the file */
	fseek(fd, SEEK_SET, 0);

	send_response(sock_control, 1); //starting

	memset(data, 0, MAXSIZE);
	while ((num_read = fread(data, 1, MAXSIZE, fd)) > 0) {
		if (send(sock_data, data, num_read, 0) < 0) {
			perror("err");
		}
		memset(data, 0, MAXSIZE);
	}

	fclose(fd);

	send_response(sock_control, 226);	// send 226

	return 0;	
}






/**
 * Open data connection to client 
 * Returns: socket for data connection
 * or -1 on error
 */
int ftserve_start_data_conn(int sock_control)
{
	char buf[1024];	
	int wait, sock_data;

	// Wait for go-ahead on control conn
	if (recv(sock_control, &wait, sizeof wait, 0) < 0 ) {
		perror("Error while waiting");
		return -1;
	}

	// Get client address
	struct sockaddr_in client_addr;
	socklen_t len = sizeof client_addr;
	getpeername(sock_control, (struct sockaddr*)&client_addr, &len);
	inet_ntop(AF_INET, &client_addr.sin_addr, buf, sizeof(buf));

	// Initiate data connection with client
	if ((sock_data = socket_connect(CLIENT_PORT_ID, buf)) < 0)
		return -1;

	return sock_data;		
}





/**
 * Authenticate a user's credentials
 * Return 1 if authenticated, 0 if not
 */
int ftserve_check_user(char*user, char*pass)
{
	char username[MAXSIZE];
	char password[MAXSIZE];
	char *pch;
	char buf[MAXSIZE];
	char *line = NULL;
	size_t num_read;									
	size_t len = 0;
	FILE* fd;
	int auth = 0;
	
	fd = fopen(".auth", "r");
	if (fd == NULL) {
		perror("file not found");
		exit(1);
	}	

	while ((num_read = getline(&line, &len, fd)) != -1) {
		memset(buf, 0, MAXSIZE);
		strcpy(buf, line);
		
		pch = strtok (buf," ");
		strcpy(username, pch);

		if (pch != NULL) {
			pch = strtok (NULL, " ");
			strcpy(password, pch);
		}

		// remove end of line and whitespace
		trimstr(password, (int)strlen(password));

		if ((strcmp(user,username)==0) && (strcmp(pass,password)==0)) {
			auth = 1;
			break;
		}		
	}
	free(line);	
	fclose(fd);	
	return auth;
}





/** 
 * Log in connected client
 */
int ftserve_login(int sock_control)
{	
	char buf[MAXSIZE];
	char user[MAXSIZE];
	char pass[MAXSIZE];	
	memset(user, 0, MAXSIZE);
	memset(pass, 0, MAXSIZE);
	memset(buf, 0, MAXSIZE);
	
	// Wait to recieve username
	if ( (recv_data(sock_control, buf, sizeof(buf)) ) == -1) {
		perror("recv error\n"); 
		exit(1);
	}	

	int i = 5;
	int n = 0;
	while (buf[i] != 0)
		user[n++] = buf[i++];
	
	// tell client we're ready for password
	send_response(sock_control, 331);					
	
	// Wait to recieve password
	memset(buf, 0, MAXSIZE);
	if ( (recv_data(sock_control, buf, sizeof(buf)) ) == -1) {
		perror("recv error\n"); 
		exit(1);
	}
	
	i = 5;
	n = 0;
	while (buf[i] != 0) {
		pass[n++] = buf[i++];
	}
	
	return (ftserve_check_user(user, pass));
}





/**
 * Wait for command from client and
 * send response
 * Returns response code
 */
int ftserve_recv_cmd(int sock_control, char*cmd, char*arg)
{	
	int rc = 200;
	char buffer[MAXSIZE];
	
	memset(buffer, 0, MAXSIZE);
	memset(cmd, 0, 5);
	memset(arg, 0, MAXSIZE);
		
	// Wait to recieve command
	if ((recv_data(sock_control, buffer, sizeof(buffer)) ) == -1) {
		perror("recv error\n"); 
		return -1;
	}
	
	strncpy(cmd, buffer, 4);
	char *tmp = buffer + 5;
	strcpy(arg, tmp);
	
	if (strcmp(cmd, "QUIT")==0) {
		rc = 221;
	} else if((strcmp(cmd, "USER")==0) || (strcmp(cmd, "PASS")==0) ||
			(strcmp(cmd, "LIST")==0) || (strcmp(cmd, "RETR")==0)) {
		rc = 200;
	} else { //invalid command
		rc = 502;
	}

	send_response(sock_control, rc);	
	return rc;
}






/** 
 * Child process handles connection to client
 */
void ftserve_process(int sock_control)
{
	int sock_data;
	char cmd[5];
	char arg[MAXSIZE];

	// Send welcome message
	send_response(sock_control, 220);

	// Authenticate user
	if (ftserve_login(sock_control) == 1) {
		send_response(sock_control, 230);
	} else {
		send_response(sock_control, 430);	
		exit(0);
	}	
	
	while (1) {
		// Wait for command
		int rc = ftserve_recv_cmd(sock_control, cmd, arg);
		
		if ((rc < 0) || (rc == 221)) {
			break;
		}
		
		if (rc == 200 ) {
			// Open data connection with client
			if ((sock_data = ftserve_start_data_conn(sock_control)) < 0) {
				close(sock_control);
				exit(1); 
			}

			// Execute command
			if (strcmp(cmd, "LIST")==0) { // Do list
				ftserve_list(sock_data, sock_control);
			} else if (strcmp(cmd, "RETR")==0) { // Do get <filename>
				ftserve_retr(sock_control, sock_data, arg);
			}
		
			// Close data connection
			close(sock_data);
		} 
	}
}




================================================
FILE: server/ftserve.h
================================================
/* ftserve.h
 *
 * Rebecca Sagalyn
 * CS372, Program 1
 * 11/15/13
 *
 * Server side of TCP file transfer implementation, runs with custom client, 
 * ftclient.c. Sends list of files in current directory and files to ftclient. 
 * Requires user login.
 * 
 * Usage: 
 *    ./ftserve PORT#
 */

#ifndef FTSERVE_H
#define FTSERVE_H

#include "../common/common.h"


/**
 * Send file specified in filename over data connection, sending
 * control message over control connection
 * Handles case of null or invalid filename
 */
void ftserve_retr(int sock_control, int sock_data, char* filename);



/**
 * Send list of files in current directory
 * over data connection
 * Return -1 on error, 0 on success
 */
int ftserve_list(int sock_data, int sock_control);




/**
 * Open data connection to client 
 * Returns: socket for data connection
 * or -1 on error
 */
int ftserve_start_data_conn(int sock_control);



/**
 * Authenticate a user's credentials
 * Return 1 if authenticated, 0 if not
 */
int ftserve_check_user(char*user, char*pass);



/** 
 * Log in connected client
 */
int ftserve_login(int sock_control);


/**
 * Wait for command from client and send response
 * Returns response code
 */
int ftserve_recv_cmd(int sock_control, char*cmd, char*arg);



/** 
 * Child process handles connection to client
 */
void ftserve_process(int sock_control);


#endif


================================================
FILE: server/makefile
================================================
CC := gcc
CFLAGS := -Wall -g -Os

SHDIR := ../common

OBJS = ftserve.o $(SHDIR)/common.o

all: ftserve

ftserve: $(OBJS)
	@$(CC) -o ftserve $(CFLAGS) $(OBJS)

$(OBJS) : %.o: %.c 
	@$(CC) -c $(CFLAGS) $< -o $@

.PHONY:
clean:
	@rm -f *.o ftserve
	@rm -f ../common/*.o
	@echo Done cleaning