Реализация простейшего FTP client/server Си под Linux
22.12.2019, 15:50. Показов 23096. Ответов 1
Реализация ftp-сервера. Команды, которые должен поддерживать сервер, должны быть следующие: положить файл, взять файл, удалить файл, показать содержимое директории и др. Должна быть совместимость со стандартным ftp-протоколом.
Реализация ftp-клиента. Команды, которые должен поддерживать клиент, должны быть следующие: положить файл, взять файл, удалить файл, показать содержимое директории, и др. Должна быть совместимость со стандартным ftp-протоколом.
FTP Server
| C | 1
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| #include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/stat.h>
#include <dirent.h>
#define N 10
#define SIZE_BUF 512
int main(int argc,char *argv[])
{
//login & password
char login[N][N], password[N][N];
int log_pass_counter = 0;
char check[128];
int login_FLAG = 0;
int password_FLAG = 0;
char trash;
int login_id;
FILE *file_login, *file_password, *file;
char directory_name[128] = "./";
char file_name[128];
int authorization_flag = 0;
int k;
DIR *dir;
struct dirent *entry;
char Buff[SIZE_BUF];
int tmp;
int socket_desc,c,client_sock,read_size;
struct sockaddr_in server, client;
socket_desc=socket(AF_INET,SOCK_STREAM,0);
if(socket_desc==-1)
{
printf("Could not create socket");
return 1;
}
puts("Socket create");
server.sin_family=AF_INET;
server.sin_addr.s_addr=INADDR_ANY;
server.sin_port=htons(8880);
if(bind(socket_desc,(struct sockaddr*)&server,sizeof(server))<0)
{
perror("Bind failed");
return 1;
}
puts("Bind done");
listen(socket_desc,100);
puts("Waiting for incoming connections...");
c=sizeof(struct sockaddr_in);
client_sock=accept(socket_desc,(struct sockaddr*)&client,(socklen_t*)&c);
if(client_sock<0)
{
perror("Accept failed");
return 1;
}
puts("Connection accept");
///load files with login and password
file_login = fopen("file_login.txt", "r");
if(!feof(file_login))
{
fscanf(file_login, "%d", &log_pass_counter);
fscanf(file_login, "%c", &trash);
printf("%d\n", log_pass_counter);
for( k = 0; k < log_pass_counter; k++)
{
//while(fgets(login[k], N, file_login) != NULL);
fread(login[k], sizeof(login[k]), 1, file_login);
//fgets(login[k], N, file_login);
puts(login[k]);
}
}
fclose(file_login);
file_password = fopen("file_password.txt", "r");
if(!feof(file_password))
{
for( k = 0; k < log_pass_counter; k++)
{
fread(password[k], sizeof(password[k]), 1, file_password);
puts(password[k]);
}
}
fclose(file_password);
/// command processing
snprintf(Buff, SIZE_BUF, "220 Welcome to the FTP Server");
send(client_sock, &Buff, SIZE_BUF, 0);
recv(client_sock, &Buff, SIZE_BUF, 0);
if( strstr(Buff, "USER") != NULL ) //processing USER command
{
tmp = strlen("USER") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
for( k = 0; k < log_pass_counter; k++)
{
if(strcmp(login[k], check) == 0)
{
login_id = k;
printf("%s\n", login[k]);
login_FLAG = 1;
}
}
if(login_FLAG)
{
//access for loginned user
snprintf(Buff, SIZE_BUF, "331 Login ok. Send your password.");
send(client_sock, &Buff, SIZE_BUF, 0);
recv(client_sock, &Buff, SIZE_BUF, 0);
if( strstr(Buff, "PASS") != NULL )
{
tmp = strlen("PASS") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
if(strcmp(password[login_id], check) == 0)
{
printf("%s\n", password[login_id]);
password_FLAG = 1;
authorization_flag = 1;
}
else
{
//send to client
printf("Password is wrong\n");
}
}
else
{
//send error command
}
login_FLAG = 0;
}
else
{
if(log_pass_counter < N)
{
//create new user
strcpy(login[log_pass_counter], check);
printf("%s\n", login[log_pass_counter]);
//create new directory for this user
snprintf(Buff, SIZE_BUF, "332 Login created. Send your password.");
send(client_sock, &Buff, SIZE_BUF, 0);
recv(client_sock, &Buff, SIZE_BUF, 0);
if( strstr(Buff, "PASS") != NULL )
{
tmp = strlen("PASS") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
strcpy(password[log_pass_counter], check);
printf("%s\n", password[log_pass_counter]);
//create directory for new user
login_id = log_pass_counter;
strcat(directory_name, login[log_pass_counter]);
tmp = mkdir(directory_name, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
if(tmp == 0)
printf("mkdir succesful");
else
printf("mkdir error");
strcpy(directory_name, "./");
authorization_flag = 1;
//write to login & password file
log_pass_counter++;
file_login = fopen("file_login.txt", "w");
fprintf(file_login, "%d", log_pass_counter);
fputs("\n", file_login);
for( k = 0; k < log_pass_counter; k++)
{
fwrite(login[k], sizeof (login[k]), 1, file_login);
}
fclose(file_login);
file_password = fopen("file_password.txt", "w");
for( k = 0; k < log_pass_counter; k++)
{
fwrite(password[k], sizeof (password[k]), 1, file_password);
}
fclose(file_password);
}
else
{
//send error command PASS
}
}
}
}
else
{
//input your username
}
if(authorization_flag == 1)
{
strcpy(directory_name, "./");
strcat(directory_name, login[login_id]);
snprintf(Buff, SIZE_BUF, "230 Guest login ok. Access restrictions apply.");
send(client_sock, &Buff, SIZE_BUF, 0);
while(authorization_flag == 1)
{
recv(client_sock, &Buff, SIZE_BUF, 0);
if( strstr(Buff, "LIST") != NULL ) // show directory
{
dir = opendir(directory_name);
if(!dir)
{
perror("diropen");
}
while((entry = readdir(dir)) != NULL)
{
printf("%10s [%4d] %8d\n", entry->d_name, entry->d_type, entry->d_reclen);
if(entry->d_type == 8) // 8 - type of file(txt, c, cpp, ...)
{
snprintf(Buff, SIZE_BUF, "%s [%d] %d\n", entry->d_name, entry->d_type, entry->d_reclen);
send(client_sock, &Buff, SIZE_BUF, 0);
}
}
closedir(dir);
//end sending
snprintf(Buff, SIZE_BUF, "END");
send(client_sock, &Buff, SIZE_BUF, 0);
}
if( strstr(Buff, "RETR") != NULL ) // transfer file from server to client
{
tmp = strlen("RETR") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
dir = opendir(directory_name);
while((entry = readdir(dir)) != NULL)
{
if( (entry->d_type == 8) && (strcmp(check, entry->d_name) == 0)) // 8 - type of file(txt, c, cpp, ...)
{
//strcpy(file_name, directory_name);
//strcat(file_name, "/");
//strcat(file_name, check);
strcpy(Buff, check);
send(client_sock, &Buff, SIZE_BUF, 0); // send filename
strcpy(file_name, directory_name);
strcat(file_name, "/");
strcat(file_name, check);
file = fopen( file_name, "r" );
for( k = 0; (tmp = getc(file)) != EOF; k++ )
{
Buff[k] = (char)tmp;
if(k == SIZE_BUF-2)
{
send(client_sock, &Buff, SIZE_BUF, 0);
k = 0;
}
}
Buff[k] = '\0';
send(client_sock, &Buff, SIZE_BUF, 0);
snprintf(Buff, SIZE_BUF, "END");
send(client_sock, &Buff, SIZE_BUF, 0);
fclose(file);
}
}
closedir(dir);
}
if( strstr(Buff, "STOR") != NULL ) // transfer file from client to server
{
tmp = strlen("STOR") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
printf("%s", check);
strcpy(file_name, directory_name);
strcat(file_name, "/");
strcat(file_name, check);
file = fopen(file_name, "w");
while(recv(client_sock, &Buff, SIZE_BUF, 0) != 0)
{
if( strcmp(Buff, "END") == 0 )
{
printf("Recive is over.\n");
break;
}
fputs(Buff, file);
printf("%s\n", Buff);
}
fclose(file);
}
if( strstr(Buff, "DELE") != NULL ) // delete file
{
tmp = strlen("DELE") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
printf("%s", check);
strcpy(file_name, directory_name);
strcat(file_name, "/");
strcat(file_name, check);
remove(file_name);
}
if( strstr(Buff, "QUIT") != NULL ) // exit
{
snprintf(Buff, SIZE_BUF, "221 Quit succesful.");
send(client_sock, &Buff, SIZE_BUF, 0);
authorization_flag = 0;
}
}
}
else
{
//sorry
}
close(socket_desc);
return 0;
} |
|
FTP Client
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| #include<sys/types.h>
#include<sys/socket.h>
#include<stdio.h>
#include<arpa/inet.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
#define N 10
#define SIZE_BUF 512
int main(int argc, char *arvg[])
{
char Buff[SIZE_BUF];
int sock = 0;
char check[128];
int tmp;
int k;
int authorization_flag = 0;
struct sockaddr_in server;
FILE *file;
sock=socket(AF_INET,SOCK_STREAM,0);
if(sock==-1)
printf("Could not create socket");
puts("Socket create");
server.sin_family=AF_INET;
server.sin_addr.s_addr=inet_addr("127.0.0.1");
server.sin_port=htons(8880);
if(connect(sock,(struct sockaddr*)&server,sizeof(server))<0)
{
perror("Connect failed");
return 1;
}
puts("Connect done");
recv(sock, &Buff, SIZE_BUF, 0); //CONNECTIONS
printf("%s\n", Buff);
gets(Buff); //USER
send(sock, &Buff, SIZE_BUF, 0);
recv(sock, &Buff, SIZE_BUF, 0); //ANSWER USER
printf("%s\n", Buff);
gets(Buff); //PASS
send(sock, &Buff, SIZE_BUF, 0);
recv(sock, &Buff, SIZE_BUF, 0); //ANSWER PASS
printf("%s\n", Buff);
if( strstr(Buff, "230") != NULL ) //processing ANSWER PASS
{
authorization_flag = 1;
}
tmp = strlen("USER") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
while(authorization_flag == 1)
{
gets(Buff);
if( strstr(Buff, "LIST") != NULL ) // show directory
{
send(sock, &Buff, SIZE_BUF, 0);
while(recv(sock, &Buff, SIZE_BUF, 0) != 0)
{
if( strcmp(Buff, "END") == 0 )
{
printf("226 Transfer complete.\n"); //finish code?
break;
}
printf("%s", Buff);
}
}
if( strstr(Buff, "RETR") != NULL ) // show directory
{
send(sock, &Buff, SIZE_BUF, 0);
recv(sock, &Buff, SIZE_BUF, 0); //file name or error
printf("%s", Buff);
if( strstr(Buff, "END") != NULL )
{
printf("505. ERROR.\n");
}
else
{
//recv(sock, &Buff, 1024, 0);
file = fopen(Buff, "w");
while(recv(sock, &Buff, SIZE_BUF, 0) != 0)
{
if( strcmp(Buff, "END") == 0 )
{
printf("226 Transfer complete.\n");
break;
}
fputs(Buff, file);
}
fclose(file);
}
}
if( strstr(Buff, "STOR") != NULL ) // show directory
{
send(sock, &Buff, SIZE_BUF, 0);
tmp = strlen("STOR") + 1;
for( k = 0; k < strlen(Buff) + 1; k++)
check[k] = Buff[tmp++];
file = fopen( check, "r" );
for( k = 0; (tmp = getc(file)) != EOF; k++ )
{
Buff[k] = (char)tmp;
if(k == SIZE_BUF-2)
{
Buff[k+1] = '\0';
send(sock, &Buff, SIZE_BUF, 0);
k = 0;
}
}
Buff[k] = '\0';
send(sock, &Buff, SIZE_BUF, 0);
snprintf(Buff, SIZE_BUF, "END");
send(sock, &Buff, SIZE_BUF, 0);
fclose(file);
}
if( strstr(Buff, "DELE") != NULL ) // show directory
{
send(sock, &Buff, SIZE_BUF, 0);
}
if( strstr(Buff, "QUIT") != NULL ) // show directory
{
send(sock, &Buff, SIZE_BUF, 0);
authorization_flag = 0;
recv(sock, &Buff, SIZE_BUF, 0); //ANSWER QUIT
printf("%s\n", Buff);
}
}
close(sock);
return 0;
} |
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Команды, поддерживаемые сервером:
0
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