/****************************************************************
 *								*
 * Copyright (c) 2006-2023 Fidelity National Information	*
 * Services, Inc. and/or its subsidiaries. All rights reserved.	*
 *								*
 *	This source code contains the intellectual property	*
 *	of its copyright holder(s), and is made available	*
 *	under a license.  If you do not know the terms of	*
 *	the license, please stop and do not read further.	*
 *								*
 ****************************************************************/

#ifndef GTMRECV_H
#define GTMRECV_H

/* Needs mdef.h, gdsfhead.h and its dependencies, and iosp.h */

#define DEFAULT_SHUTDOWN_TIMEOUT	30  /* seconds */
#define	MAX_FILTER_CMD_LEN		512 /* characters */
#define UPD_HELPERS_DELIM		','
#define MAX_UPD_HELPERS			128 /* Max helper process (incl. readers and writers) one instance can support */
#define MIN_UPD_HELPERS			1   /* Minimum number of helper processes, one for reading or writing */

#define DEFAULT_UPD_HELPERS		8	/* If value for -HELPERS is not specified, start these many helpers. Change
						 * DEFAULT_UPD_HELPERS_STR if you change DEFAULT_UPD_HELPERS */
#define DEFAULT_UPD_HELP_READERS	5	/* If -HELPERS is not specified, or specified as -HELPERS=,n start these many
						 * readers. Change DEFAULT_UPD_HELPERS_STR if you change DEFAULT_UPD_HELP_READERS */
#define DEFAULT_UPD_HELPERS_STR		"8,5"	/* Built as "DEFAULT_UPD_HELPERS,DEFAULT_UPD_HELP_READERS". Maintain DEFAULT for
						 * /helpers in vvms:mupip_cmd.cld in sync with DEFAULT_UPD_HELPERS_STR */

#ifdef VMS
#define MAX_GSEC_KEY_LEN		32 /* 31 is allowed + 1 for NULL terminator */
#endif

typedef enum
{
	GTMRECV_DUMMY_STATE = 0,
	GTMRECV_START,
	GTMRECV_WAITING_FOR_CONNECTION,
	GTMRECV_RECEIVING_MSGS,
	GTMRECV_WAITING_FOR_UPD_CRASH_RESTART,
	GTMRECV_WAITING_FOR_UPD_SHUT_RESTART
} gtmrecv_state_t;

enum
{
	UPDPROC_STARTED,
	UPDPROC_START,
	UPDPROC_EXISTS,
	UPDPROC_START_ERR
};

enum
{
	GTMRECV_NO_RESTART,
	GTMRECV_RCVR_RESTARTED,
	GTMRECV_UPD_RESTARTED
};

enum
{
	HELPER_REAP_NONE = 0,
	HELPER_REAP_NOWAIT,
	HELPER_REAP_WAIT
};

#define GTMRECV_WAIT_FOR_PROC_SLOTS     1 /* s */
#define GTMRECV_WAIT_FOR_UPDSTART	(1000 - 1) /* ms */
#define GTMRECV_WAIT_FOR_UPD_SHUTDOWN	10 /* ms */
#define GTMRECV_MAX_UPDSTART_ATTEMPTS   16
#define GTMRECV_WAIT_FOR_RECVSTART      (1000 - 1) /* ms */
#define	GTMRECV_WAIT_FOR_SRV_START	10 /* ms */
#define GTMRECV_REAP_HELPERS_INTERVAL	300 /* s */


#define SRV_ALIVE		0x0
#define SRV_DEAD		0x1
#define SRV_ERR			0x2

/* The exit status of checkhealth is BIT-OR of the Receiver status and the
 * Update status */
#define	RECEIVER_SRV_ALIVE		0x00
#define RECEIVER_SRV_DEAD		0x01
#define RECEIVER_CHECKHEALTH_ERR	0x02
#define UPDATE_PROC_ALIVE		0x00
#define UPDATE_PROC_DEAD		0x04
#define UPDATE_CHECKHEALTH_ERR		0x08
#define RECVPOOL_SEGMENT		'R'
#define DEFAULT_RECVPOOL_SIZE		(2 << 25)		/* 64MiB */
#define MIN_RECVPOOL_SIZE		(2 << 19)		/* 1MiB */
#define MAX_RECVPOOL_SIZE		(0x1000000000LL)	/* 64GB */

#define GTMRECV_MIN_TCP_SEND_BUFSIZE	(512)		/* anything less than this, issue a warning */
#define GTMRECV_TCP_SEND_BUFSIZE	(1024)		/* not much outbound traffic, we can live with a low limit */
#define GTMRECV_MIN_TCP_RECV_BUFSIZE	(16   * 1024)	/* anything less than this, issue a warning */
#define GTMRECV_TCP_RECV_BUFSIZE_INCR	(32   * 1024)	/* attempt to get a larger buffer with this increment */
#define GTMRECV_TCP_RECV_BUFSIZE	(1024 * 1024)	/* desirable to set the buffer size to be able to receive large chunks */

#define	IS_RCVR_SRVR_FALSE		FALSE
#define	IS_RCVR_SRVR_TRUE		TRUE

#include <pthread.h>

/* Note: fields shared between the receiver and update processes
 *	really need to have memory barriers or other appropriate
 *	synchronization constructs to ensure changes by one
 *	process are actually seen by the other process.  Cache
 *	line spacing should also be taken into account.
 *	Adding volatile is only a start at this.
 */

typedef struct
{
	replpool_identifier	recvpool_id;	/* Shared memory identification */
	volatile seq_num	jnl_seqno; 	/* Sequence number of the next transaction expected to be received from source
			    	 		 * server. Updated by Receiver Server */
	seq_num			old_jnl_seqno;	/* Stores the value of jnl_seqno before it is set to 0 when upd crash/shut */
	repl_conn_info_t	this_side;	/* Replication connection details of this side/instance */
	gtm_uint64_t		recvdata_base_off; 	/* Receive pool offset from where journal data starts */
	gtm_uint64_t		recvpool_size; 	/* Available space for journal data in bytes */
	volatile gtm_uint64_t	write;		/* Relative offset from recvdata_base_off for for the next journal record to be
						 * written. Updated by Receiver Server */
	volatile gtm_uint64_t	write_wrap;	/* Relative offset from recvdata_base_off where write was wrapped by recvr srvr */
	volatile uint4		wrapped;	/* Boolean, set by Receiver Server when it wraps. Reset by Update Process when it
						 * wraps. Used for detecting space used in the receive pool */
	uint4			initialized;	/* Boolean, has receive pool been initialized? */
	uint4			fresh_start;	/* Boolean, fresh_start or crash_start? */
	repl_histinfo		last_rcvd_histinfo;	/* history from the last received REPL_HISTREC message */
	repl_histinfo		last_valid_histinfo;	/* history corresponding to last logical record written
							 * into receive pool by the receiver. This is almost always
							 * the same as last_rcvd_histinfo except in the window
							 * between receiving a new REPL_HISTREC and the first
							 * logical records corresponding to it.
							 */
	repl_histinfo		last_rcvd_strm_histinfo[MAX_SUPPL_STRMS];	/* same as last_rcvd_histinfo but for each
										 * non-supplementary stream. Used only in a
										 * propagating supplementary instance.
										 */
	repl_histinfo		last_valid_strm_histinfo[MAX_SUPPL_STRMS];	/* same as last_valid_histinfo but for each
										 * non-supplementary stream. Used only in a
										 * propagating supplementary instance.
										 */
	boolean_t		is_valid_strm_histinfo[MAX_SUPPL_STRMS];	/* TRUE if corresponding entry in
										 * "last_rcvd_strm_histinfo[]" array is valid
										 */
	uint4			max_strm_histinfo;	/* maximum valid index in "is_valid_strm_histinfo" array */
	boolean_t		insert_strm_histinfo;	/* true for a supplementary propagating primary if the receiver
							 * has to insert REPL_HISTREC records for each valid stream
							 * into the receive pool.
							 */
	pthread_mutex_t		write_updated_ctl;
	pthread_cond_t		write_updated;
} recvpool_ctl_struct;

#define	INSERT_STRM_HISTINFO_FALSE	FALSE
#define	INSERT_STRM_HISTINFO_TRUE	TRUE

#define	GTMRECV_CLEAR_CACHED_HISTINFO(RECVPOOL_CTL, JNLPOOL, INSERT_STRM_HISTINFO)						\
{																\
	memset(&RECVPOOL_CTL->last_rcvd_histinfo, 0, SIZEOF(RECVPOOL_CTL->last_rcvd_histinfo));					\
	memset(&RECVPOOL_CTL->last_valid_histinfo, 0, SIZEOF(RECVPOOL_CTL->last_valid_histinfo));				\
	assert((NULL != JNLPOOL) && (NULL != JNLPOOL->repl_inst_filehdr));							\
	assert(NULL != JNLPOOL->jnlpool_ctl);											\
	if (JNLPOOL->repl_inst_filehdr->is_supplementary && JNLPOOL->jnlpool_ctl->upd_disabled)					\
	{	/* The below fields are used only in case of a supplementary instance where updates are disabled.		\
		 * So avoid initializing them in any other case.								\
		 */														\
		memset(&RECVPOOL_CTL->last_rcvd_strm_histinfo[0], 0, SIZEOF(RECVPOOL_CTL->last_rcvd_strm_histinfo));		\
		memset(&RECVPOOL_CTL->last_valid_strm_histinfo[0], 0, SIZEOF(RECVPOOL_CTL->last_valid_strm_histinfo));		\
		memset(&RECVPOOL_CTL->is_valid_strm_histinfo[0], 0, SIZEOF(RECVPOOL_CTL->is_valid_strm_histinfo));		\
		RECVPOOL_CTL->max_strm_histinfo = 0;										\
		assert((0 == RECVPOOL_CTL->jnl_seqno)										\
			|| ((0 < RECVPOOL_CTL->jnl_seqno) && (RECVPOOL_CTL->jnl_seqno >= JNLPOOL->jnlpool_ctl->jnl_seqno)));	\
		assert(0 < JNLPOOL->jnlpool_ctl->jnl_seqno);									\
		RECVPOOL_CTL->insert_strm_histinfo = INSERT_STRM_HISTINFO;							\
	}															\
}

/*
 * The following structure contains Update Process related data items.
 * Maintaining this structure in the Receive pool provides for
 * persistence across instantiations of the Update Process (across crashes,
 * the receive pool is preserved)
 */

typedef struct
{
	uint4		upd_proc_pid;		/* Process identification of update server */
	uint4		upd_proc_pid_prev;      /* Save for reporting old pid if we fail */
	volatile seq_num read_jnl_seqno;	/* Next jnl_seqno to be read; keep aligned at 8 byte boundary for performance */
	volatile gtm_uint64_t	read; 		/* Relative offset from recvdata_base_off of the next journal record to be
						 * read from the receive pool */
	volatile uint4	upd_proc_shutdown;      /* Used to communicate shutdown related values between Receiver and Update */
	volatile int4	upd_proc_shutdown_time; /* Time allowed for update process to shut down */
	volatile uint4	bad_trans;		/* Boolean, set by Update Process that it received a bad transaction record */
	volatile uint4	changelog;		/* Boolean - change the log file */
	int4		start_upd;		/* Used to communicate upd only startup values */
	volatile uint4	log_interval;		/* Interval (in seqnos) at which update process logs its progress */
	char		log_file[MAX_FN_LEN + 1];
	volatile uint4	onln_rlbk_flg;		/* Set to TRUE every time update process sees an online rollback. Set to FALSE ONLY
						 * by receiver server */
} upd_proc_local_struct;

/*
 * The following structure contains data items local to the Receiver Server,
 * but are in the Receive Pool to provide for persistence across instantiations
 * of the Receiver Server (across Receiver Server crashes, the Receive
 * Pool is preserved).
 */
typedef struct
{
	uint4		recv_serv_pid;		/* Process identification of receiver server */
	int4		lastrecvd_time;		/* unused */
	/* Data items used in communicating action qualifiers (show statistics, shutdown) and
	 * qualifier values (log file, shutdown time, etc). */
	volatile uint4	statslog;		/* Boolean - detailed log on/off? */
	volatile uint4	shutdown;		/* Used to communicate shutdown related values between process initiating shutdown
					 	 * and Receiver Server */
	int4		shutdown_time;		/* Time allowed for shutdown in seconds */
	int4		listen_port;		/* Port at which the Receiver Server is listening */
	volatile uint4	restart;		/* Used by receiver server to coordinate crash restart with update process */
	volatile uint4	changelog;		/* Boolean - change the log file */
	volatile uint4	log_interval;		/* Interval (in seqnos) at which receiver logs its progress */
	char		filter_cmd[MAX_FILTER_CMD_LEN];	/* Receiver filters incoming records using this process */
	char		log_file[MAX_FN_LEN + 1];	/* File to log receiver progress */
	char		statslog_file[MAX_FN_LEN + 1];	/* File to log statistics */
	repl_conn_info_t	remote_side;	/* Details of the remote side/instance of the connection */
	int4		strm_index;
	boolean_t	updateresync;		/* Copy of gtmrecv_options.updateresync; This is cleared once first history
						 * record gets applied on the receiver after the first connect with a source.
						 */
	boolean_t	noresync;		/* Copy of gtmrecv_options.noresync; This is cleared once first history
						 * record gets applied on the receiver after the first connect with a source.
						 */
	int		updresync_instfile_fd;	/* fd of the instance file name specified in -UPDATERESYNC= */
	int4		updresync_num_histinfo;	/* "num_histinfo" member of instance file header from -UPDATERESYNC=<INSTFILE> */
	boolean_t	updresync_cross_endian;	/* is the -updateresync instance file cross endian relative to current instance */
	int4		updresync_num_histinfo_strm[MAX_SUPPL_STRMS];	/* "last_histinfo_num[]" member of instance file header
									 * from -UPDATERESYNC=<INSTFILE> */
	repl_inst_uuid	updresync_lms_group;	/* "lms_group_info" member of instance file header from -UPDATERESYNC=<INSTFILE> */
	seq_num		updresync_jnl_seqno;	/* "jnl_seqno" member of instance file header from -UPDATERESYNC=<INSTFILE> */
	repl_inst_uuid	remote_lms_group;	/* "lms_group_info" member of remote instance file header.
						 * Initialized only if the receiving instance is a supplementary root primary. */
} gtmrecv_local_struct;

#ifdef VMS
typedef struct
{
	char			name[MAX_GSEC_KEY_LEN];
	struct dsc$descriptor_s desc;
	char			filler[3];
} vms_shm_key;
#endif

/*
 * The following structure contains data items local to the Update Helpers,
 * but are in the Receive Pool to provide for persistence across instantiations
 * of the Helpers (the Receive Pool is preserved across helper crashes).
 */

typedef struct
{
	uint4		helper_pid;	/* Owner of this entry. Non-zero indicates entry occupied */
	uint4		helper_pid_prev;/* Copy of helper_pid, used to recognize helpers that are now gone and salvage entries */
	uint4		helper_type;	/* READER or WRITER */
	volatile uint4	helper_shutdown;/* used to communicate to the helpers to shut down */
} upd_helper_entry_struct;

typedef struct
{
	global_latch_t		pre_read_lock;		/* operated by pre-readers. Used to control access to next_read_offset */
	volatile uint4		pre_read_offset;	/* updated by updproc, read-only by pre-readers */
	volatile boolean_t	first_done;		/* pre-readers use this to elect ONE that computes where to begin/resume */
	volatile uint4		next_read_offset;	/* offset in recvpool of the next record to be pre-read by pre-readers */
	uint4			start_helpers;		/* TRUE: receiver to start helpers, FALSE: receiver finished helper start */
	uint4			start_n_readers;	/* start/started these many readers */
	uint4			start_n_writers;	/* start/started these many writers */
	uint4			reap_helpers;		/* receiver to salvage slots vacated by dead helpers */
	upd_helper_entry_struct	helper_list[MAX_UPD_HELPERS];	/* helper information */
} upd_helper_ctl_struct;

/*
 * Receive pool shared memory layout -
 *
 * recvpool_ctl_struct
 * upd_proc_local_struct
 * gtmrecv_local_struct
 * upd_helper_ctl_struct
 * zero or more journal records
 */

#define RECVPOOL_CTL_SIZE	ROUND_UP(SIZEOF(recvpool_ctl_struct),   CACHELINE_SIZE)
#define UPD_PROC_LOCAL_SIZE	ROUND_UP(SIZEOF(upd_proc_local_struct), CACHELINE_SIZE)
#define GTMRECV_LOCAL_SIZE	ROUND_UP(SIZEOF(gtmrecv_local_struct),  CACHELINE_SIZE)
#define UPD_HELPER_CTL_SIZE	ROUND_UP(SIZEOF(upd_helper_ctl_struct), CACHELINE_SIZE)

#define RECVDATA_BASE_OFF	ROUND_UP(RECVPOOL_CTL_SIZE + UPD_HELPER_CTL_SIZE + GTMRECV_LOCAL_SIZE + UPD_HELPER_CTL_SIZE, \
						JNL_REC_START_BNDRY)

#if defined(__osf__) && defined(__alpha)
# pragma pointer_size(save)
# pragma pointer_size(long)
#endif

typedef recvpool_ctl_struct	*recvpool_ctl_ptr_t;
typedef upd_proc_local_struct	*upd_proc_local_ptr_t;
typedef gtmrecv_local_struct	*gtmrecv_local_ptr_t;
typedef	upd_helper_entry_struct	*upd_helper_entry_ptr_t;
typedef	upd_helper_ctl_struct	*upd_helper_ctl_ptr_t;

#if defined(__osf__) && defined(__alpha)
# pragma pointer_size(restore)
#endif

typedef struct
{
	recvpool_ctl_ptr_t	recvpool_ctl;
	upd_proc_local_ptr_t	upd_proc_local;
	gtmrecv_local_ptr_t	gtmrecv_local;
	upd_helper_ctl_ptr_t	upd_helper_ctl;
	sm_uc_ptr_t		recvdata_base;
#ifdef UNIX
	gd_region		*recvpool_dummy_reg;
#elif VMS
	int4			shm_range[2];
	int4			shm_lockid;
	vms_shm_key		vms_recvpool_key;
#endif
} recvpool_addrs;

typedef enum
{
	UPDPROC,
	UPD_HELPER_READER,
	UPD_HELPER_WRITER,
	GTMRECV,
#	ifdef UNIX
	GTMZPEEK
#	endif
#	ifdef VMS
	GTMRECV_CHILD
#	endif
} recvpool_user;

typedef struct
{
	boolean_t	start;
	boolean_t	shut_down;
	boolean_t	checkhealth;
	boolean_t	statslog;
	boolean_t	showbacklog;
	boolean_t	updateonly;
	boolean_t	stopsourcefilter;
	boolean_t	changelog;
	gtm_uint64_t	buffsize;
	int4		shutdown_time;
	int4		listen_port;
	boolean_t	updateresync;
	boolean_t	noresync;
	uint4		rcvr_log_interval;
	uint4		upd_log_interval;
	boolean_t	helpers;
	boolean_t	reuse_specified;
	boolean_t	resume_specified;
	boolean_t	initialize_specified;
	int4		resume_strm_num;
	int4		n_readers;
	int4		n_writers;
	int4		cmplvl;
	char            log_file[MAX_FN_LEN + 1];
	char		updresync_instfilename[MAX_FN_LEN + 1];
	char            filter_cmd[MAX_FILTER_CMD_LEN];
	char		reuse_instname[MAX_INSTNAME_LEN];
	boolean_t	autorollback;
	boolean_t	autorollback_verbose;
	boolean_t	stopreceiverfilter;
	int4		send_buffsize;
	int4		recv_buffsize;
} gtmrecv_options_t;

#include "gtm_inet.h"

/********** Receiver server function prototypes **********/
int		gtmrecv(void);
int		gtmrecv_changelog(void);
int		gtmrecv_checkhealth(void);
int		gtmrecv_comm_init(in_port_t port);
int		gtmrecv_end1(boolean_t auto_shutdown);
int		gtmrecv_endupd(void);
void		gtmrecv_end(void);
int		gtmrecv_get_opt(void);
int		gtmrecv_poll_actions1(int *pending_data_len, int *buff_unprocessed, unsigned char *buffp);
int		gtmrecv_poll_actions(int pending_data_len, int buff_unprocessed, unsigned char *buffp);
void		gtmrecv_process(boolean_t crash_restart);
int		gtmrecv_showbacklog(void);
int		gtmrecv_shutdown(boolean_t auto_shutdown, int exit_status);
void		gtmrecv_sigstop(void);
void		gtmrecv_autoshutdown(void);
int		gtmrecv_statslog(void);
int		gtmrecv_ipc_cleanup(boolean_t auto_shutdown, int *exit_status);
int		gtmrecv_start_updonly(void);
int		gtmrecv_upd_proc_init(boolean_t fresh_start);
int		gtmrecv_wait_for_detach(void);
void		gtmrecv_exit(int exit_status);
int		gtmrecv_alloc_msgbuff(void);
void		gtmrecv_free_msgbuff(void);
int		gtmrecv_alloc_filter_buff(int bufsiz);
void		gtmrecv_free_filter_buff(void);
int		is_updproc_alive(void);
int		is_srv_alive(int srv_type);
int		is_recv_srv_alive(void);
void		recvpool_init(recvpool_user pool_user, boolean_t gtmrecv_startup);
void		gtmrecv_reinit_logseqno(void);
int		gtmrecv_helpers_init(int n_readers, int n_writers);
int		gtmrecv_start_helpers(int n_readers, int n_writers);
void		gtmrecv_reap_helpers(boolean_t wait);
int		gtmrecv_end_helpers(boolean_t is_rcvr_srvr);
void		gtmrecv_onln_rlbk_clnup(void);
int		gtmrecv_stopfilter(void);

#endif