samba-mirror/ctdb/include/ctdb_private.h

/* 
   ctdb database library

   Copyright (C) Andrew Tridgell  2006

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef _CTDB_PRIVATE_H
#define _CTDB_PRIVATE_H

#include "ctdb.h"

/* location of daemon socket */
#define CTDB_PATH	"/tmp/ctdb.socket"

/* we must align packets to ensure ctdb works on all architectures (eg. sparc) */
#define CTDB_DS_ALIGNMENT 8


#define CTDB_NULL_FUNC     0xF0000001

#define CTDB_CURRENT_NODE  0xF0000001
#define CTDB_BROADCAST_VNN 0xF0000002


/*
  an installed ctdb remote call
*/
struct ctdb_registered_call {
	struct ctdb_registered_call *next, *prev;
	uint32_t id;
	ctdb_fn_t fn;
};

/*
  this address structure might need to be generalised later for some
  transports
*/
struct ctdb_address {
	const char *address;
	int port;
};

/*
  check a vnn is valid
 */
#define ctdb_validate_vnn(ctdb, vnn) (((uint32_t)(vnn)) < (ctdb)->num_nodes)


/* called from the queue code when a packet comes in. Called with data==NULL
   on error */
typedef void (*ctdb_queue_cb_fn_t)(uint8_t *data, size_t length,
				   void *private_data);

/* used for callbacks in ctdb_control requests */
typedef void (*ctdb_control_callback_fn_t)(struct ctdb_context *,
					   uint32_t status, TDB_DATA data, 
					   void *private_data);

/*
  state associated with one node
*/
struct ctdb_node {
	struct ctdb_context *ctdb;
	struct ctdb_address address;
	const char *name; /* for debug messages */
	void *private_data; /* private to transport */
	uint32_t vnn;
#define NODE_FLAGS_CONNECTED 0x00000001
	uint32_t flags;
};

/*
  transport specific methods
*/
struct ctdb_methods {
	int (*start)(struct ctdb_context *); /* start protocol processing */	
	int (*add_node)(struct ctdb_node *); /* setup a new node */	
	int (*queue_pkt)(struct ctdb_node *, uint8_t *data, uint32_t length);
	void *(*allocate_pkt)(TALLOC_CTX *mem_ctx, size_t );
};

/*
  transport calls up to the ctdb layer
*/
struct ctdb_upcalls {
	/* recv_pkt is called when a packet comes in */
	void (*recv_pkt)(struct ctdb_context *, uint8_t *data, uint32_t length);

	/* node_dead is called when an attempt to send to a node fails */
	void (*node_dead)(struct ctdb_node *);

	/* node_connected is called when a connection to a node is established */
	void (*node_connected)(struct ctdb_node *);
};

/* list of message handlers - needs to be changed to a more efficient data
   structure so we can find a message handler given a srvid quickly */
struct ctdb_message_list {
	struct ctdb_context *ctdb;
	struct ctdb_message_list *next, *prev;
	uint64_t srvid;
	ctdb_message_fn_t message_handler;
	void *message_private;
};

/* additional data required for the daemon mode */
struct ctdb_daemon_data {
	int sd;
	char *name;
	struct ctdb_queue *queue;
};

/*
  ctdb status information
 */
struct ctdb_status {
	uint32_t client_packets_sent;
	uint32_t client_packets_recv;
	uint32_t node_packets_sent;
	uint32_t node_packets_recv;
	struct {
		uint32_t req_call;
		uint32_t reply_call;
		uint32_t reply_redirect;
		uint32_t req_dmaster;
		uint32_t reply_dmaster;
		uint32_t reply_error;
		uint32_t req_message;
		uint32_t req_finished;
		uint32_t req_control;
		uint32_t reply_control;
	} count;
	struct {
		uint32_t req_call;
		uint32_t req_message;
		uint32_t req_finished;
		uint32_t req_register;
		uint32_t req_connect_wait;
		uint32_t req_shutdown;
		uint32_t req_control;
	} client;
	uint32_t total_calls;
	uint32_t pending_calls;
	uint32_t lockwait_calls;
	uint32_t pending_lockwait_calls;
	uint32_t __last_uint32; /* hack for control_status_all */
	uint32_t max_redirect_count;
	double max_call_latency;
	double max_lockwait_latency;
};

/* table that contains the mapping between a hash value and lmaster
 */
struct ctdb_vnn_map {
	uint32_t generation;
	uint32_t size;
	uint32_t *map;
};

/* main state of the ctdb daemon */
struct ctdb_context {
	struct event_context *ev;
	struct ctdb_address address;
	const char *name;
	const char *db_directory;
	const char *transport;
	uint32_t vnn; /* our own vnn */
	uint32_t num_nodes;
	uint32_t num_connected;
	uint32_t num_finished;
	unsigned flags;
	struct idr_context *idr;
	uint16_t idr_cnt;
	struct ctdb_node **nodes; /* array of nodes in the cluster - indexed by vnn */
	char *err_msg;
	const struct ctdb_methods *methods; /* transport methods */
	const struct ctdb_upcalls *upcalls; /* transport upcalls */
	void *private_data; /* private to transport */
	unsigned max_lacount;
	struct ctdb_db_context *db_list;
	struct ctdb_message_list *message_list;
	struct ctdb_daemon_data daemon;
	struct ctdb_status status;
	struct ctdb_vnn_map *vnn_map;
	uint32_t num_clients;
};

struct ctdb_db_context {
	struct ctdb_db_context *next, *prev;
	struct ctdb_context *ctdb;
	uint32_t db_id;
	const char *db_name;
	const char *db_path;
	struct tdb_wrap *ltdb;
	struct ctdb_registered_call *calls; /* list of registered calls */
};


#define CTDB_NO_MEMORY(ctdb, p) do { if (!(p)) { \
          ctdb_set_error(ctdb, "Out of memory at %s:%d", __FILE__, __LINE__); \
	  return -1; }} while (0)

#define CTDB_NO_MEMORY_VOID(ctdb, p) do { if (!(p)) { \
          ctdb_set_error(ctdb, "Out of memory at %s:%d", __FILE__, __LINE__); \
	  }} while (0)

#define CTDB_NO_MEMORY_NULL(ctdb, p) do { if (!(p)) { \
          ctdb_set_error(ctdb, "Out of memory at %s:%d", __FILE__, __LINE__); \
	  return NULL; }} while (0)

#define CTDB_NO_MEMORY_FATAL(ctdb, p) do { if (!(p)) { \
          ctdb_fatal(ctdb, "Out of memory in " __location__ ); \
	  }} while (0)

/* arbitrary maximum timeout for ctdb operations */
#define CTDB_REQ_TIMEOUT 0

/* max number of redirects before we ask the lmaster */
#define CTDB_MAX_REDIRECT 2

/* number of consecutive calls from the same node before we give them
   the record */
#define CTDB_DEFAULT_MAX_LACOUNT 7

/*
  the extended header for records in the ltdb
*/
struct ctdb_ltdb_header {
	uint64_t rsn;
	uint32_t dmaster;
	uint32_t laccessor;
	uint32_t lacount;
};

enum ctdb_controls {CTDB_CONTROL_PROCESS_EXISTS, 
		    CTDB_CONTROL_STATUS, 
		    CTDB_CONTROL_CONFIG,
		    CTDB_CONTROL_PING,
		    CTDB_CONTROL_GETDBPATH,
		    CTDB_CONTROL_GETVNNMAP,
		    CTDB_CONTROL_SETVNNMAP,
		    CTDB_CONTROL_GET_DEBUG,
		    CTDB_CONTROL_SET_DEBUG,
		    CTDB_CONTROL_GET_DBMAP,
		    CTDB_CONTROL_GET_NODEMAP};

enum call_state {CTDB_CALL_WAIT, CTDB_CALL_DONE, CTDB_CALL_ERROR};

/*
  state of a in-progress ctdb call
*/
struct ctdb_call_state {
	enum call_state state;
	uint32_t reqid;
	struct ctdb_req_call *c;
	struct ctdb_db_context *ctdb_db;
	struct ctdb_node *node;
	const char *errmsg;
	struct ctdb_call call;
	int redirect_count;
	struct ctdb_ltdb_header header;
	struct {
		void (*fn)(struct ctdb_call_state *);
		void *private_data;
	} async;
};


/* used for fetch_lock */
struct ctdb_fetch_handle {
	struct ctdb_db_context *ctdb_db;
	TDB_DATA key;
	TDB_DATA *data;
	struct ctdb_ltdb_header header;
};

/*
  operation IDs
*/
enum ctdb_operation {
	CTDB_REQ_CALL           = 0,
	CTDB_REPLY_CALL         = 1,
	CTDB_REPLY_REDIRECT     = 2,
	CTDB_REQ_DMASTER        = 3,
	CTDB_REPLY_DMASTER      = 4,
	CTDB_REPLY_ERROR        = 5,
	CTDB_REQ_MESSAGE        = 6,
	CTDB_REQ_FINISHED       = 7,
	CTDB_REQ_CONTROL        = 8,
	CTDB_REPLY_CONTROL      = 9,
	
	/* only used on the domain socket */
	CTDB_REQ_REGISTER       = 1000,     
	CTDB_REQ_CONNECT_WAIT   = 1001,
	CTDB_REPLY_CONNECT_WAIT = 1002,
	CTDB_REQ_SHUTDOWN       = 1003
};

#define CTDB_MAGIC 0x43544442 /* CTDB */
#define CTDB_VERSION 1

/*
  packet structures
*/
struct ctdb_req_header {
	uint32_t length;
	uint32_t ctdb_magic;
	uint32_t ctdb_version;
	uint32_t generation;
	uint32_t operation;
	uint32_t destnode;
	uint32_t srcnode;
	uint32_t reqid;
};

struct ctdb_req_call {
	struct ctdb_req_header hdr;
	uint32_t flags;
	uint32_t db_id;
	uint32_t callid;
	uint32_t keylen;
	uint32_t calldatalen;
	uint8_t data[1]; /* key[] followed by calldata[] */
};

struct ctdb_reply_call {
	struct ctdb_req_header hdr;
	uint32_t status;
	uint32_t datalen;
	uint8_t  data[1];
};

struct ctdb_reply_error {
	struct ctdb_req_header hdr;
	uint32_t status;
	uint32_t msglen;
	uint8_t  msg[1];
};

struct ctdb_reply_redirect {
	struct ctdb_req_header hdr;
	uint32_t dmaster;
};

struct ctdb_req_dmaster {
	struct ctdb_req_header hdr;
	uint32_t db_id;
	uint32_t dmaster;
	uint32_t keylen;
	uint32_t datalen;
	uint8_t  data[1];
};

struct ctdb_reply_dmaster {
	struct ctdb_req_header hdr;
	uint32_t datalen;
	uint8_t  data[1];
};

struct ctdb_req_register {
	struct ctdb_req_header hdr;
	uint64_t srvid;
};

struct ctdb_req_message {
	struct ctdb_req_header hdr;
	uint64_t srvid;
	uint32_t datalen;
	uint8_t data[1];
};

struct ctdb_req_finished {
	struct ctdb_req_header hdr;
};

struct ctdb_req_shutdown {
	struct ctdb_req_header hdr;
};

struct ctdb_req_connect_wait {
	struct ctdb_req_header hdr;
};

struct ctdb_reply_connect_wait {
	struct ctdb_req_header hdr;
	uint32_t vnn;
	uint32_t num_connected;
};

struct ctdb_req_getdbpath {
	struct ctdb_req_header hdr;
	uint32_t db_id;
};

struct ctdb_reply_getdbpath {
	struct ctdb_req_header hdr;
	uint32_t datalen;
	uint8_t data[1];
};

struct ctdb_req_control {
	struct ctdb_req_header hdr;
	uint32_t opcode;
	uint64_t srvid;
	uint32_t datalen;
	uint8_t data[1];
};

struct ctdb_reply_control {
	struct ctdb_req_header hdr;
	int32_t  status;
	uint32_t datalen;
	uint8_t data[1];
};


/* internal prototypes */
void ctdb_set_error(struct ctdb_context *ctdb, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
void ctdb_fatal(struct ctdb_context *ctdb, const char *msg);
bool ctdb_same_address(struct ctdb_address *a1, struct ctdb_address *a2);
int ctdb_parse_address(struct ctdb_context *ctdb,
		       TALLOC_CTX *mem_ctx, const char *str,
		       struct ctdb_address *address);
uint32_t ctdb_hash(const TDB_DATA *key);
void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_request_dmaster(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_request_message(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_reply_dmaster(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_reply_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_reply_error(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_reply_redirect(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);

uint32_t ctdb_lmaster(struct ctdb_context *ctdb, const TDB_DATA *key);
int ctdb_ltdb_fetch(struct ctdb_db_context *ctdb_db, 
		    TDB_DATA key, struct ctdb_ltdb_header *header, 
		    TALLOC_CTX *mem_ctx, TDB_DATA *data);
int ctdb_ltdb_store(struct ctdb_db_context *ctdb_db, TDB_DATA key, 
		    struct ctdb_ltdb_header *header, TDB_DATA data);
void ctdb_queue_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
int ctdb_ltdb_lock_requeue(struct ctdb_db_context *ctdb_db, 
			   TDB_DATA key, struct ctdb_req_header *hdr,
			   void (*recv_pkt)(void *, uint8_t *, uint32_t ),
			   void *recv_context);
int ctdb_ltdb_lock_fetch_requeue(struct ctdb_db_context *ctdb_db, 
				 TDB_DATA key, struct ctdb_ltdb_header *header, 
				 struct ctdb_req_header *hdr, TDB_DATA *data,
				 void (*recv_pkt)(void *, uint8_t *, uint32_t ),
				 void *recv_context);
void ctdb_recv_pkt(struct ctdb_context *ctdb, uint8_t *data, uint32_t length);

struct ctdb_call_state *ctdb_call_local_send(struct ctdb_db_context *ctdb_db, 
					     struct ctdb_call *call,
					     struct ctdb_ltdb_header *header,
					     TDB_DATA *data);


int ctdbd_start(struct ctdb_context *ctdb);
struct ctdb_call_state *ctdbd_call_send(struct ctdb_db_context *ctdb_db, struct ctdb_call *call);
int ctdbd_call_recv(struct ctdb_call_state *state, struct ctdb_call *call);

/*
  queue a packet for sending
*/
int ctdb_queue_send(struct ctdb_queue *queue, uint8_t *data, uint32_t length);

/*
  setup the fd used by the queue
 */
int ctdb_queue_set_fd(struct ctdb_queue *queue, int fd);

/*
  setup a packet queue on a socket
 */
struct ctdb_queue *ctdb_queue_setup(struct ctdb_context *ctdb,
				    TALLOC_CTX *mem_ctx, int fd, int alignment,
				    
				    ctdb_queue_cb_fn_t callback,
				    void *private_data);

/*
  allocate a packet for use in client<->daemon communication
 */
struct ctdb_req_header *_ctdbd_allocate_pkt(struct ctdb_context *ctdb,
					    TALLOC_CTX *mem_ctx, 
					    enum ctdb_operation operation, 
					    size_t length, size_t slength,
					    const char *type);
#define ctdbd_allocate_pkt(ctdb, mem_ctx, operation, length, type) \
	(type *)_ctdbd_allocate_pkt(ctdb, mem_ctx, operation, length, sizeof(type), #type)

struct ctdb_req_header *_ctdb_transport_allocate(struct ctdb_context *ctdb,
						 TALLOC_CTX *mem_ctx, 
						 enum ctdb_operation operation, 
						 size_t length, size_t slength,
						 const char *type);
#define ctdb_transport_allocate(ctdb, mem_ctx, operation, length, type) \
	(type *)_ctdb_transport_allocate(ctdb, mem_ctx, operation, length, sizeof(type), #type)


/*
  lock a record in the ltdb, given a key
 */
int ctdb_ltdb_lock(struct ctdb_db_context *ctdb_db, TDB_DATA key);

/*
  unlock a record in the ltdb, given a key
 */
int ctdb_ltdb_unlock(struct ctdb_db_context *ctdb_db, TDB_DATA key);


/*
  make a ctdb call to the local daemon - async send. Called from client context.

  This constructs a ctdb_call request and queues it for processing. 
  This call never blocks.
*/
struct ctdb_call_state *ctdb_client_call_send(struct ctdb_db_context *ctdb_db, 
					      struct ctdb_call *call);

/*
  make a recv call to the local ctdb daemon - called from client context

  This is called when the program wants to wait for a ctdb_call to complete and get the 
  results. This call will block unless the call has already completed.
*/
int ctdb_client_call_recv(struct ctdb_call_state *state, struct ctdb_call *call);

int ctdb_daemon_set_message_handler(struct ctdb_context *ctdb, uint64_t srvid, 
			     ctdb_message_fn_t handler,
			     void *private_data);

int ctdb_client_send_message(struct ctdb_context *ctdb, uint32_t vnn,
			     uint64_t srvid, TDB_DATA data);

/*
  send a ctdb message
*/
int ctdb_daemon_send_message(struct ctdb_context *ctdb, uint32_t vnn,
			     uint64_t srvid, TDB_DATA data);


/*
  wait for all nodes to be connected
*/
void ctdb_daemon_connect_wait(struct ctdb_context *ctdb);


struct lockwait_handle *ctdb_lockwait(struct ctdb_db_context *ctdb_db,
				      TDB_DATA key,
				      void (*callback)(void *), void *private_data);

struct ctdb_call_state *ctdb_daemon_call_send(struct ctdb_db_context *ctdb_db, 
					      struct ctdb_call *call);

int ctdb_daemon_call_recv(struct ctdb_call_state *state, struct ctdb_call *call);

struct ctdb_call_state *ctdb_daemon_call_send_remote(struct ctdb_db_context *ctdb_db, 
						     struct ctdb_call *call, 
						     struct ctdb_ltdb_header *header);

void ctdb_request_finished(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);

int ctdb_call_local(struct ctdb_db_context *ctdb_db, struct ctdb_call *call,
		    struct ctdb_ltdb_header *header, TDB_DATA *data,
		    uint32_t caller);

#define ctdb_reqid_find(ctdb, reqid, type)	(type *)_ctdb_reqid_find(ctdb, reqid, #type, __location__)

void ctdb_recv_raw_pkt(void *p, uint8_t *data, uint32_t length);

int ctdb_socket_connect(struct ctdb_context *ctdb);

void ctdb_latency(double *latency, struct timeval t);

uint32_t ctdb_reqid_new(struct ctdb_context *ctdb, void *state);
void *_ctdb_reqid_find(struct ctdb_context *ctdb, uint32_t reqid, const char *type, const char *location);
void ctdb_reqid_remove(struct ctdb_context *ctdb, uint32_t reqid);

void ctdb_request_control(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
void ctdb_reply_control(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);

int ctdb_daemon_send_control(struct ctdb_context *ctdb, uint32_t destnode,
			     uint64_t srvid, uint32_t opcode, TDB_DATA data,
			     ctdb_control_callback_fn_t callback,
			     void *private_data);

#endif