// main client handler procedure, runs in its own thread void * thread_proc(void * param) { CLIENT_INFO client_info; memset(&client_info, 0, sizeof(client_info)); client_info.fd = (int)param; strcpy(client_info.dir, "/"); send_code(client_info.fd, 220); while (1) { int result = client_read(client_info.fd, client_info.buf, &client_info.buffer_pos); if (result == -1) break; while (client_info.buffer_pos >= 4) { char line[BUFFER_SIZE] = { 0 }; if (compare_command(client_info.buf, "USER")) command_user(&client_info); else if (compare_command(client_info.buf, "PASS")) command_pass(&client_info); else if (compare_command(client_info.buf, "PWD")) command_pwd(&client_info); else if (compare_command(client_info.buf, "PORT")) command_port(&client_info); else if (compare_command(client_info.buf, "PASV")) command_pasv(&client_info); else if (compare_command(client_info.buf, "LIST")) command_list(&client_info); else if (compare_command(client_info.buf, "CWD")) command_cwd(&client_info); else if (compare_command(client_info.buf, "RETR")) command_retr(&client_info); else if (compare_command(client_info.buf, "NOOP")) command_noop(&client_info); else if (compare_command(client_info.buf, "SYST")) command_syst(&client_info); else if (compare_command(client_info.buf, "TYPE")) command_type(&client_info); else if (compare_command(client_info.buf, "QUIT")) { get_line(client_info.fd, line, client_info.buf, &client_info.buffer_pos); send_code(client_info.fd, 221); close(client_info.fd); client_info.fd = 0; return NULL; } else { get_line(client_info.fd, line, client_info.buf, &client_info.buffer_pos); send_code(client_info.fd, 500); } } } if (client_info.fd != 0) { close(client_info.fd); client_info.fd = 0; } return NULL; }
/*PAGE * * exec_command * * Parse and execute FTP command. * * FIXME: This section is somewhat of a hack. We should have a better * way to parse commands. * * Input parameters: * info - corresponding SessionInfo structure * cmd - command to be executed (upper-case) * args - arguments of the command * * Output parameters: * NONE */ static void exec_command(FTPD_SessionInfo_t *info, char* cmd, char* args) { char fname[FTPD_BUFSIZE]; int wrong_command = 0; fname[0] = '\0'; if (!strcmp("PORT", cmd)) { command_port(info, args); } else if (!strcmp("PASV", cmd)) { command_pasv(info); } else if (!strcmp("RETR", cmd)) { strncpy(fname, args, 254); command_retrieve(info, fname); } else if (!strcmp("STOR", cmd)) { strncpy(fname, args, 254); command_store(info, fname); } else if (!strcmp("LIST", cmd)) { strncpy(fname, args, 254); command_list(info, fname, 1); } else if (!strcmp("NLST", cmd)) { strncpy(fname, args, 254); command_list(info, fname, 0); } else if (!strcmp("MDTM", cmd)) { strncpy(fname, args, 254); command_mdtm(info, fname); } else if (!strcmp("SYST", cmd)) { send_reply(info, 215, FTPD_SYSTYPE); } else if (!strcmp("TYPE", cmd)) { if (args[0] == 'I') { info->xfer_mode = TYPE_I; send_reply(info, 200, "Type set to I."); } else if (args[0] == 'A') { info->xfer_mode = TYPE_A; send_reply(info, 200, "Type set to A."); } else { info->xfer_mode = TYPE_I; send_reply(info, 504, "Type not implemented. Set to I."); } } else if (!strcmp("USER", cmd) || !strcmp("PASS", cmd)) { send_reply(info, 230, "User logged in."); } else if (!strcmp("DELE", cmd)) { if(!can_write()) { send_reply(info, 550, "Access denied."); } else if ( strncpy(fname, args, 254) && unlink(fname) == 0) { send_reply(info, 257, "DELE successful."); } else { send_reply(info, 550, "DELE failed."); } } else if (!strcmp("SITE", cmd)) { char* opts; split_command(args, &cmd, &opts, &args); if(!strcmp("CHMOD", cmd)) { int mask; if(!can_write()) { send_reply(info, 550, "Access denied."); } else { char *c; c = strchr(args, ' '); if((c != NULL) && (sscanf(args, "%o", &mask) == 1) && strncpy(fname, c+1, 254) && (chmod(fname, (mode_t)mask) == 0)) send_reply(info, 257, "CHMOD successful."); else send_reply(info, 550, "CHMOD failed."); } } else wrong_command = 1; } else if (!strcmp("RMD", cmd)) { if(!can_write()) { send_reply(info, 550, "Access denied."); } else if ( strncpy(fname, args, 254) && rmdir(fname) == 0) { send_reply(info, 257, "RMD successful."); } else { send_reply(info, 550, "RMD failed."); } } else if (!strcmp("MKD", cmd)) { if(!can_write()) { send_reply(info, 550, "Access denied."); } else if ( strncpy(fname, args, 254) && mkdir(fname, S_IRWXU | S_IRWXG | S_IRWXO) == 0) { send_reply(info, 257, "MKD successful."); } else { send_reply(info, 550, "MKD failed."); } } else if (!strcmp("CWD", cmd)) { strncpy(fname, args, 254); command_cwd(info, fname); } else if (!strcmp("CDUP", cmd)) { command_cwd(info, ".."); } else if (!strcmp("PWD", cmd)) { command_pwd(info); } else wrong_command = 1; if(wrong_command) send_reply(info, 500, "Command not understood."); }