ftpsrvr.c

/* Synchronet FTP server */

/****************************************************************************
 * @format.tab-size 4		(Plain Text/Source Code File Header)			*
 * @format.use-tabs true	(see http://www.synchro.net/ptsc_hdr.html)		*
 *																			*
 * Copyright Rob Swindell - http://www.synchro.net/copyright.html			*
 *																			*
 * This program is free software; you can redistribute it and/or			*
 * modify it under the terms of the GNU General Public License				*
 * as published by the Free Software Foundation; either version 2			*
 * of the License, or (at your option) any later version.					*
 * See the GNU General Public License for more details: gpl.txt or			*
 * http://www.fsf.org/copyleft/gpl.html										*
 *																			*
 * For Synchronet coding style and modification guidelines, see				*
 * http://www.synchro.net/source.html										*
 *																			*
 * Note: If this box doesn't appear square, then you need to fix your tabs.	*
 ****************************************************************************/

/* ANSI C Library headers */
#include <stdio.h>
#include <stdlib.h>         /* ltoa in GNU C lib */
#include <stdarg.h>         /* va_list, varargs */
#include <string.h>         /* strrchr */
#include <fcntl.h>          /* O_WRONLY, O_RDONLY, etc. */
#include <errno.h>          /* EACCES */
#include <ctype.h>          /* toupper */
#include <sys/types.h>
#include <sys/stat.h>

/* Synchronet-specific headers */
#undef SBBS /* this shouldn't be defined unless building sbbs.dll/libsbbs.so */
#include "sbbs.h"
#include "text.h"           /* TOTAL_TEXT */
#include "ftpsrvr.h"
#include "filedat.h"
#include "telnet.h"
#include "multisock.h"
#include "ssl.h"
#include "cryptlib.h"
#include "xpprintf.h"       // vasprintf
#include "md5.h"
#include "sauce.h"
#include "git_branch.h"
#include "git_hash.h"

/* Constants */

#define FTP_SERVER              "Synchronet FTP Server"
static const char* server_abbrev = "ftp";

#define ANONYMOUS               "anonymous"

#define BBS_VIRTUAL_PATH        "bbs:/""/"  /* this is actually bbs:<slash><slash> */
#define LOCAL_FSYS_DIR          "local:"
#define BBS_FSYS_DIR            "bbs:"
#define BBS_HIDDEN_ALIAS        "hidden"

#define TIMEOUT_THREAD_WAIT     60      /* Seconds */

#define TIMEOUT_SOCKET_LISTEN   30      /* Seconds */

#define XFER_REPORT_INTERVAL    60      /* Seconds */

#define INDEX_FNAME_LEN         15

#define NAME_LEN                15      /* User name length for listings */

#define MLSX_TYPE   (1 << 0)
#define MLSX_PERM   (1 << 1)
#define MLSX_SIZE   (1 << 2)
#define MLSX_MODIFY (1 << 3)
#define MLSX_OWNER  (1 << 4)
#define MLSX_UNIQUE (1 << 5)
#define MLSX_CREATE (1 << 6)

static ftp_startup_t*     startup = NULL;
static scfg_t             scfg;
static struct mqtt        mqtt;
static struct xpms_set *  ftp_set = NULL;
static protected_uint32_t active_clients;
static protected_uint32_t thread_count;
static volatile uint32_t  client_highwater = 0;
static volatile time_t    uptime = 0;
static volatile ulong     served = 0;
static bool               terminate_server = FALSE;
static char *             text[TOTAL_TEXT];
static str_list_t         pause_semfiles;
static str_list_t         recycle_semfiles;
static str_list_t         shutdown_semfiles;
static link_list_t        current_connections;

#ifdef SOCKET_DEBUG
static BYTE               socket_debug[0x10000] = {0};

	#define SOCKET_DEBUG_CTRL       (1 << 0)  /* 0x01 */
	#define SOCKET_DEBUG_SEND       (1 << 1)  /* 0x02 */
	#define SOCKET_DEBUG_READLINE   (1 << 2)  /* 0x04 */
	#define SOCKET_DEBUG_ACCEPT     (1 << 3)  /* 0x08 */
	#define SOCKET_DEBUG_SENDTHREAD (1 << 4)  /* 0x10 */
	#define SOCKET_DEBUG_TERMINATE  (1 << 5)  /* 0x20 */
	#define SOCKET_DEBUG_RECV_CHAR  (1 << 6)  /* 0x40 */
	#define SOCKET_DEBUG_FILEXFER   (1 << 7)  /* 0x80 */
#endif

char* genvpath(int lib, int dir, char* str);

typedef struct {
	SOCKET socket;
	union xp_sockaddr client_addr;
	socklen_t client_addr_len;
} ftp_t;


static const char *ftp_mon[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun"
	                            , "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

BOOL direxist(char *dir)
{
	if (access(dir, 0) == 0)
		return TRUE;
	else
		return FALSE;
}

BOOL dir_op(scfg_t* cfg, user_t* user, client_t* client, uint dirnum)
{
	return user_is_dirop(cfg, dirnum, user, client);
}

static int lputs(int level, const char* str)
{
	mqtt_lputs(&mqtt, TOPIC_SERVER, level, str);
	if (level <= LOG_ERR) {
		char errmsg[1024];
		SAFEPRINTF2(errmsg, "%-4s %s", server_abbrev, str);
		errorlog(&scfg, &mqtt, level, startup == NULL ? NULL : startup->host_name, errmsg);
		if (startup != NULL && startup->errormsg != NULL)
			startup->errormsg(startup->cbdata, level, errmsg);
	}

	if (startup == NULL || startup->lputs == NULL || str == NULL || level > startup->log_level)
		return 0;

#if defined(_WIN32)
	if (IsBadCodePtr((FARPROC)startup->lputs))
		return 0;
#endif

	return startup->lputs(startup->cbdata, level, str);
}

#if defined(__GNUC__)   // Catch printf-format errors with lprintf
static int lprintf(int level, const char *fmt, ...) __attribute__ ((format (printf, 2, 3)));
#endif
static int lprintf(int level, const char *fmt, ...)
{
	va_list argptr;
	char    sbuf[1024];

	va_start(argptr, fmt);
	vsnprintf(sbuf, sizeof(sbuf), fmt, argptr);
	sbuf[sizeof(sbuf) - 1] = 0;
	va_end(argptr);

	return lputs(level, sbuf);
}

#ifdef _WINSOCKAPI_

static WSADATA WSAData;
#define SOCKLIB_DESC WSAData.szDescription

static BOOL    WSAInitialized = FALSE;

static BOOL winsock_startup(void)
{
	int status;                 /* Status Code */

	if ((status = WSAStartup(MAKEWORD(1, 1), &WSAData)) == 0) {
		lprintf(LOG_DEBUG, "%s %s", WSAData.szDescription, WSAData.szSystemStatus);
		WSAInitialized = TRUE;
		return TRUE;
	}

	lprintf(LOG_CRIT, "!WinSock startup ERROR %d", status);
	return FALSE;
}

#else /* No WINSOCK */

#define winsock_startup()   (TRUE)
#define SOCKLIB_DESC        NULL

#endif

static char* server_host_name(void)
{