path: root/source3/rpc_server/srv_eventlog_lib.c

/* 
 *  Unix SMB/CIFS implementation.
 *  Eventlog utility  routines
 *  Copyright (C) Marcin Krzysztof Porwit    2005,
 *  Copyright (C) Gerald (Jerry) Carter      2005.
 *  
 *  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.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "includes.h"


/****************************************************************
Init an Eventlog TDB, and return it. If null, something bad happened.
****************************************************************/
TDB_CONTEXT *init_eventlog_tdb( char *tdbfilename )
{
	TDB_CONTEXT *the_tdb;

	unlink( tdbfilename );

	the_tdb =
		tdb_open_log( tdbfilename, 0, TDB_DEFAULT, O_RDWR | O_CREAT,
			      0664 );
	if ( the_tdb == NULL ) {
		DEBUG( 1, ( "Can't open tdb for [%s]\n", tdbfilename ) );
		return NULL;
	}
	tdb_store_int32( the_tdb, VN_oldest_entry, 1 );
	tdb_store_int32( the_tdb, VN_next_record, 1 );

	/* initialize with defaults, copy real values in here from registry */

	tdb_store_int32( the_tdb, VN_maxsize, 0x80000 );
	tdb_store_int32( the_tdb, VN_retention, 0x93A80 );

	tdb_store_int32( the_tdb, VN_version, EVENTLOG_DATABASE_VERSION_V1 );
	return the_tdb;
}

/* make the tdb file name for an event log, given destination buffer and size */
char *mk_tdbfilename( char *dest_buffer, char *eventlog_name, int size_dest )
{
	pstring ondisk_name;

	if ( !dest_buffer )
		return NULL;

	pstrcpy( ondisk_name, "EV" );
	pstrcat( ondisk_name, eventlog_name );
	pstrcat( ondisk_name, ".tdb" );

	memset( dest_buffer, 0, size_dest );

	/* BAD things could happen if the dest_buffer is not large enough... */
	if ( strlen( ondisk_name ) > size_dest ) {
		DEBUG( 3, ( "Buffer not big enough for filename\n" ) );
		return NULL;
	}

	strncpy( dest_buffer, ondisk_name, size_dest );

	return dest_buffer;
}


/* count the number of bytes in the TDB */

/* Arg! Static Globals! */

static int eventlog_tdbcount;
static int eventlog_tdbsize;

/* this function is used to count up the number of bytes in a particular TDB */
int eventlog_tdb_size_fn( TDB_CONTEXT * tdb, TDB_DATA key, TDB_DATA data,
			  void *state )
{
	eventlog_tdbsize += data.dsize;
	eventlog_tdbcount++;
	return 0;
}

/* returns the size of the eventlog, and if MaxSize is a non-null ptr, puts 
   the MaxSize there. This is purely a way not to have yet another function that solely
   reads the maxsize of the eventlog. Yeah, that's it.  */

int eventlog_tdb_size( TDB_CONTEXT * tdb, int *MaxSize, int *Retention )
{
	if ( !tdb )
		return 0;
	eventlog_tdbcount = 0;
	eventlog_tdbsize = 0;

	tdb_traverse( tdb, eventlog_tdb_size_fn, NULL );

	if ( MaxSize != NULL ) {
		*MaxSize = tdb_fetch_int32( tdb, VN_maxsize );
	}

	if ( Retention != NULL ) {
		*Retention = tdb_fetch_int32( tdb, VN_retention );
	}

	DEBUG( 1,
	       ( "eventlog size: [%d] for [%d] records\n", eventlog_tdbsize,
		 eventlog_tdbcount ) );
	return eventlog_tdbsize;
}


/* 
   Discard early event logs until we have enough for 'needed' bytes...
   NO checking done beforehand to see that we actually need to do this, and
   it's going to pluck records one-by-one. So, it's best to determine that this 
   needs to be done before doing it.  

   Setting whack_by_date to True indicates that eventlogs falling outside of the 
   retention range need to go...

*/

/* return True if we made enough room to accommodate needed bytes */

BOOL make_way_for_eventlogs( TDB_CONTEXT * the_tdb, int32 needed,
			     BOOL whack_by_date )
{
	int start_record, i, new_start;
	int end_record;
	int nbytes, reclen, len, Retention, MaxSize;

	int tresv1, trecnum, timegen, timewr;

	TDB_DATA key, ret;
	TALLOC_CTX *mem_ctx = NULL;

	time_t current_time, exp_time;

	/* discard some eventlogs */

	/* read eventlogs from oldest_entry -- there can't be any discontinuity in recnos,
	   although records not necessarily guaranteed to have successive times */
	/* */
	mem_ctx = talloc_init( "make_way_for_eventlogs" );	/* Homage to BPG */

	if ( mem_ctx == NULL )
		return False;	/* can't allocate memory indicates bigger problems */
	/* lock */
	tdb_lock_bystring( the_tdb, VN_next_record, 1 );
	/* read */
	end_record = tdb_fetch_int32( the_tdb, VN_next_record );
	start_record = tdb_fetch_int32( the_tdb, VN_oldest_entry );
	Retention = tdb_fetch_int32( the_tdb, VN_retention );
	MaxSize = tdb_fetch_int32( the_tdb, VN_maxsize );

	time( &current_time );

	/* calculate ... */
	exp_time = current_time - Retention;	/* discard older than exp_time */

	/* todo - check for sanity in next_record */
	nbytes = 0;

	DEBUG( 3,
	       ( "MaxSize [%d] Retention [%d] Current Time [%d]  exp_time [%d]\n",
		 MaxSize, Retention, (uint32)current_time, (uint32)exp_time ) );
	DEBUG( 3,
	       ( "Start Record [%d] End Record [%d]\n", start_record,
		 end_record ) );

	for ( i = start_record; i < end_record; i++ ) {
		/* read a record, add the amt to nbytes */
		key.dsize = sizeof( int32 );
		key.dptr = ( char * ) ( int32 * ) & i;
		ret = tdb_fetch( the_tdb, key );
		if ( ret.dsize == 0 ) {
			DEBUG( 8,
			       ( "Can't find a record for the key, record [%d]\n",
				 i ) );
			tdb_unlock_bystring( the_tdb, VN_next_record );
			return False;
		}
		nbytes += ret.dsize;	/* note this includes overhead */

		len = tdb_unpack( ret.dptr, ret.dsize, "ddddd", &reclen,
				  &tresv1, &trecnum, &timegen, &timewr );
		DEBUG( 8,
		       ( "read record %d, record size is [%d], total so far [%d]\n",
			 i, reclen, nbytes ) );

		SAFE_FREE( ret.dptr );

		/* note that other servers may just stop writing records when the size limit
		   is reached, and there are no records older than 'retention'. This doesn't 
		   like a very useful thing to do, so instead we whack (as in sleeps with the 
		   fishes) just enough records to fit the what we need.  This behavior could
		   be changed to 'match', if the need arises. */

		if ( !whack_by_date && ( nbytes >= needed ) )
			break;	/* done */
		if ( whack_by_date && ( timegen >= exp_time ) )
			break;	/* done */
	}

	DEBUG( 3,
	       ( "nbytes [%d] needed [%d] start_record is [%d], should be set to [%d]\n",
		 nbytes, needed, start_record, i ) );
	/* todo - remove eventlog entries here and set starting record to start_record... */
	new_start = i;
	if ( start_record != new_start ) {
		for ( i = start_record; i < new_start; i++ ) {
			key.dsize = sizeof( int32 );
			key.dptr = ( char * ) ( int32 * ) & i;
			tdb_delete( the_tdb, key );
		}

		tdb_store_int32( the_tdb, VN_oldest_entry, new_start );
	}
	tdb_unlock_bystring( the_tdb, VN_next_record );
	return True;
}

/*
  some hygiene for an eventlog - see how big it is, and then 
  calculate how many bytes we need to remove                   
*/

BOOL prune_eventlog( TDB_CONTEXT * tdb )
{
	int MaxSize, Retention, CalcdSize;

	if ( !tdb ) {
		DEBUG( 4, ( "No eventlog tdb handle\n" ) );
		return False;
	}

	CalcdSize = eventlog_tdb_size( tdb, &MaxSize, &Retention );
	DEBUG( 3,
	       ( "Calculated size [%d] MaxSize [%d]\n", CalcdSize,
		 MaxSize ) );

	if ( CalcdSize > MaxSize ) {
		return make_way_for_eventlogs( tdb, CalcdSize - MaxSize,
					       False );
	}

	return make_way_for_eventlogs( tdb, 0, True );
}

BOOL can_write_to_eventlog( TDB_CONTEXT * tdb, int32 needed )
{
	int calcd_size;
	int MaxSize, Retention;

	/* see if we can write to the eventlog -- do a policy enforcement */
	if ( !tdb )
		return False;	/* tdb is null, so we can't write to it */


	if ( needed < 0 )
		return False;
	MaxSize = 0;
	Retention = 0;

	calcd_size = eventlog_tdb_size( tdb, &MaxSize, &Retention );

	if ( calcd_size <= MaxSize )
		return True;	/* you betcha */
	if ( calcd_size + needed < MaxSize )
		return True;

	if ( Retention == 0xffffffff ) {
		return False;	/* see msdn - we can't write no room, discard */
	}
	/*
	   note don't have to test, but always good to show intent, in case changes needed
	   later
	 */

	if ( Retention == 0x00000000 ) {
		/* discard record(s) */
		/* todo  - decide when to remove a bunch vs. just what we need... */
		return make_way_for_eventlogs( tdb, calcd_size - MaxSize,
					       True );
	}

	return make_way_for_eventlogs( tdb, calcd_size - MaxSize, False );
}

TDB_CONTEXT *open_eventlog_tdb( char *tdbfilename )
{
	TDB_CONTEXT *the_tdb;

	the_tdb =
		tdb_open_log( tdbfilename, 0, TDB_DEFAULT, O_RDWR | O_CREAT,
			      0664 );
	if ( the_tdb == NULL ) {
		return init_eventlog_tdb( tdbfilename );
	}
	if ( EVENTLOG_DATABASE_VERSION_V1 !=
	     tdb_fetch_int32( the_tdb, VN_version ) ) {
		tdb_close( the_tdb );
		return init_eventlog_tdb( tdbfilename );
	}
	return the_tdb;
}

/* write an eventlog entry. Note that we have to lock, read next eventlog, increment, write, write the record, unlock */

/* coming into this, ee has the eventlog record, and the auxilliary date (computer name, etc.) 
   filled into the other structure. Before packing into a record, this routine will calc the 
   appropriate padding, etc., and then blast out the record in a form that can be read back in */
int write_eventlog_tdb( TDB_CONTEXT * the_tdb, Eventlog_entry * ee )
{
	int32 next_record;
	uint8 *packed_ee;
	TALLOC_CTX *mem_ctx = NULL;
	TDB_DATA kbuf, ebuf;
	uint32 n_packed;

	if ( !ee )
		return 0;

	mem_ctx = talloc_init( "write_eventlog_tdb" );

	if ( mem_ctx == NULL )
		return 0;

	if ( !ee )
		return 0;
	/* discard any entries that have bogus time, which usually indicates a bogus entry as well. */
	if ( ee->record.time_generated == 0 )
		return 0;

#define MARGIN 512

	/* todo - check for sanity in next_record */

	fixup_eventlog_entry( ee );

	if ( !can_write_to_eventlog( the_tdb, ee->record.length ) ) {
		DEBUG( 3, ( "Can't write to Eventlog, no room \n" ) );
		talloc_destroy( mem_ctx );
		return 0;
	}

	/* alloc mem for the packed version */
	packed_ee = TALLOC( mem_ctx, ee->record.length + MARGIN );
	if ( !packed_ee ) {
		talloc_destroy( mem_ctx );
		return 0;
	}

	/* need to read the record number and insert it into the entry here */

	/* lock */
	tdb_lock_bystring( the_tdb, VN_next_record, 1 );
	/* read */
	next_record = tdb_fetch_int32( the_tdb, VN_next_record );

	n_packed =
		tdb_pack( packed_ee, ee->record.length + MARGIN,
			  "ddddddwwwwddddddBBdBBBd", ee->record.length,
			  ee->record.reserved1, next_record,
			  ee->record.time_generated, ee->record.time_written,
			  ee->record.event_id, ee->record.event_type,
			  ee->record.num_strings, ee->record.event_category,
			  ee->record.reserved2,
			  ee->record.closing_record_number,
			  ee->record.string_offset,
			  ee->record.user_sid_length,
			  ee->record.user_sid_offset, ee->record.data_length,
			  ee->record.data_offset,
			  ee->data_record.source_name_len,
			  ee->data_record.source_name,
			  ee->data_record.computer_name_len,
			  ee->data_record.computer_name,
			  ee->data_record.sid_padding,
			  ee->record.user_sid_length, ee->data_record.sid,
			  ee->data_record.strings_len,
			  ee->data_record.strings,
			  ee->data_record.user_data_len,
			  ee->data_record.user_data,
			  ee->data_record.data_padding );

	/*DEBUG(3,("write_eventlog_tdb: packed into  %d\n",n_packed)); */

	/* increment the record count */

	kbuf.dsize = sizeof( int32 );
	kbuf.dptr = ( uint8 * ) & next_record;

	ebuf.dsize = n_packed;
	ebuf.dptr = packed_ee;

	if ( tdb_store( the_tdb, kbuf, ebuf, 0 ) ) {
		/* DEBUG(1,("write_eventlog_tdb: Can't write record %d to eventlog\n",next_record)); */
		tdb_unlock_bystring( the_tdb, VN_next_record );
		talloc_destroy( mem_ctx );
		return 0;
	}
	next_record++;
	tdb_store_int32( the_tdb, VN_next_record, next_record );
	tdb_unlock_bystring( the_tdb, VN_next_record );
	talloc_destroy( mem_ctx );
	return ( next_record - 1 );
}

/* calculate the correct fields etc for an eventlog entry */

void fixup_eventlog_entry( Eventlog_entry * ee )
{
	/* fix up the eventlog entry structure as necessary */

	ee->data_record.sid_padding =
		( ( 4 -
		    ( ( ee->data_record.source_name_len +
			ee->data_record.computer_name_len ) % 4 ) ) % 4 );
	ee->data_record.data_padding =
		( 4 -
		  ( ( ee->data_record.strings_len +
		      ee->data_record.user_data_len ) % 4 ) ) % 4;
	ee->record.length = sizeof( Eventlog_record );
	ee->record.length += ee->data_record.source_name_len;
	ee->record.length += ee->data_record.computer_name_len;
	if ( ee->record.user_sid_length == 0 ) {
		/* Should not pad to a DWORD boundary for writing out the sid if there is
		   no SID, so just propagate the padding to pad the data */
		ee->data_record.data_padding += ee->data_record.sid_padding;
		ee->data_record.sid_padding = 0;
	}
	/* DEBUG(10, ("sid_padding is [%d].\n", ee->data_record.sid_padding)); */
	/* DEBUG(10, ("data_padding is [%d].\n", ee->data_record.data_padding)); */

	ee->record.length += ee->data_record.sid_padding;
	ee->record.length += ee->record.user_sid_length;
	ee->record.length += ee->data_record.strings_len;
	ee->record.length += ee->data_record.user_data_len;
	ee->record.length += ee->data_record.data_padding;
	/* need another copy of length at the end of the data */
	ee->record.length += sizeof( ee->record.length );
}

/********************************************************************
Note that it's a pretty good idea to initialize the Eventlog_entry structure to zero's before
calling parse_logentry on an batch of lines that may resolve to a record.
ALSO, it's a good idea to remove any linefeeds (that's EOL to you and me) on the lines going in.

********************************************************************/

BOOL parse_logentry( char *line, Eventlog_entry * entry, BOOL * eor )
{
	char *start = NULL, *stop = NULL;
	pstring temp;
	int temp_len = 0;

	start = line;

	/* empty line signyfiying record delimeter, or we're at the end of the buffer */
	if ( start == NULL || strlen( start ) == 0 ) {
		DEBUG( 6,
		       ( "parse_logentry: found end-of-record indicator.\n" ) );
		*eor = True;
		return True;
	}
	if ( !( stop = strchr( line, ':' ) ) ) {
		return False;
	}

	DEBUG( 6, ( "parse_logentry: trying to parse [%s].\n", line ) );

	if ( 0 == strncmp( start, "LEN", stop - start ) ) {
		/* This will get recomputed later anyway -- probably not necessary */
		entry->record.length = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "RS1", stop - start ) ) {
		/* For now all these reserved entries seem to have the same value,
		   which can be hardcoded to int(1699505740) for now */
		entry->record.reserved1 = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "RCN", stop - start ) ) {
		entry->record.record_number = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "TMG", stop - start ) ) {
		entry->record.time_generated = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "TMW", stop - start ) ) {
		entry->record.time_written = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "EID", stop - start ) ) {
		entry->record.event_id = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "ETP", stop - start ) ) {
		if ( strstr( start, "ERROR" ) ) {
			entry->record.event_type = EVENTLOG_ERROR_TYPE;
		} else if ( strstr( start, "WARNING" ) ) {
			entry->record.event_type = EVENTLOG_WARNING_TYPE;
		} else if ( strstr( start, "INFO" ) ) {
			entry->record.event_type = EVENTLOG_INFORMATION_TYPE;
		} else if ( strstr( start, "AUDIT_SUCCESS" ) ) {
			entry->record.event_type = EVENTLOG_AUDIT_SUCCESS;
		} else if ( strstr( start, "AUDIT_FAILURE" ) ) {
			entry->record.event_type = EVENTLOG_AUDIT_FAILURE;
		} else if ( strstr( start, "SUCCESS" ) ) {
			entry->record.event_type = EVENTLOG_SUCCESS;
		} else {
			/* some other eventlog type -- currently not defined in MSDN docs, so error out */
			return False;
		}
	}

/*
  else if(0 == strncmp(start, "NST", stop - start))
  {
  entry->record.num_strings = atoi(stop + 1);
  }
*/
	else if ( 0 == strncmp( start, "ECT", stop - start ) ) {
		entry->record.event_category = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "RS2", stop - start ) ) {
		entry->record.reserved2 = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "CRN", stop - start ) ) {
		entry->record.closing_record_number = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "USL", stop - start ) ) {
		entry->record.user_sid_length = atoi( stop + 1 );
	} else if ( 0 == strncmp( start, "SRC", stop - start ) ) {
		memset( temp, 0, sizeof( temp ) );
		stop++;
		while ( isspace( stop[0] ) ) {
			stop++;
		}
		temp_len = strlen( stop );
		strncpy( temp, stop, temp_len );
		rpcstr_push( ( void * ) ( entry->data_record.source_name ),
			     temp, sizeof( entry->data_record.source_name ),
			     STR_TERMINATE );
		entry->data_record.source_name_len =
			( strlen_w( entry->data_record.source_name ) * 2 ) +
			2;
	} else if ( 0 == strncmp( start, "SRN", stop - start ) ) {
		memset( temp, 0, sizeof( temp ) );
		stop++;
		while ( isspace( stop[0] ) ) {
			stop++;
		}
		temp_len = strlen( stop );
		strncpy( temp, stop, temp_len );
		rpcstr_push( ( void * ) ( entry->data_record.computer_name ),
			     temp, sizeof( entry->data_record.computer_name ),
			     STR_TERMINATE );
		entry->data_record.computer_name_len =
			( strlen_w( entry->data_record.computer_name ) * 2 ) +
			2;
	} else if ( 0 == strncmp( start, "SID", stop - start ) ) {
		memset( temp, 0, sizeof( temp ) );
		stop++;
		while ( isspace( stop[0] ) ) {
			stop++;
		}
		temp_len = strlen( stop );
		strncpy( temp, stop, temp_len );
		rpcstr_push( ( void * ) ( entry->data_record.sid ), temp,
			     sizeof( entry->data_record.sid ),
			     STR_TERMINATE );
		entry->record.user_sid_length =
			( strlen_w( entry->data_record.sid ) * 2 ) + 2;
	} else if ( 0 == strncmp( start, "STR", stop - start ) ) {
		/* skip past initial ":" */
		stop++;
		/* now skip any other leading whitespace */
		while ( isspace( stop[0] ) ) {
			stop++;
		}
		temp_len = strlen( stop );
		memset( temp, 0, sizeof( temp ) );
		strncpy( temp, stop, temp_len );
		rpcstr_push( ( void * ) ( entry->data_record.strings +
					  entry->data_record.strings_len ),
			     temp,
			     sizeof( entry->data_record.strings ) -
			     entry->data_record.strings_len, STR_TERMINATE );
		entry->data_record.strings_len += temp_len + 1;
		entry->record.num_strings++;
	} else if ( 0 == strncmp( start, "DAT", stop - start ) ) {
		/* Now that we're done processing the STR data, adjust the length to account for
		   unicode, then proceed with the DAT data. */
		entry->data_record.strings_len *= 2;
		/* skip past initial ":" */
		stop++;
		/* now skip any other leading whitespace */
		while ( isspace( stop[0] ) ) {
			stop++;
		}
		entry->data_record.user_data_len = strlen( stop );
		memset( entry->data_record.user_data, 0,
			sizeof( entry->data_record.user_data ) );
		if ( entry->data_record.user_data_len > 0 ) {
			/* copy no more than the first 1024 bytes */
			if ( entry->data_record.user_data_len >
			     sizeof( entry->data_record.user_data ) )
				entry->data_record.user_data_len =
					sizeof( entry->data_record.
						user_data );
			memcpy( entry->data_record.user_data, stop,
				entry->data_record.user_data_len );
		}
	} else {
		/* some other eventlog entry -- not implemented, so dropping on the floor */
		DEBUG( 10, ( "Unknown entry [%s]. Ignoring.\n", line ) );
		/* For now return true so that we can keep on parsing this mess. Eventually
		   we will return False here. */
		return True;
	}
	return True;
}