samba-mirror/ctdb/common/ctdb.c

/* 
   ctdb main protocol code

   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
*/

#include "includes.h"
#include "lib/tdb/include/tdb.h"
#include "lib/events/events.h"
#include "lib/util/dlinklist.h"
#include "system/network.h"
#include "system/filesys.h"
#include "../include/ctdb_private.h"

/*
  choose the transport we will use
*/
int ctdb_set_transport(struct ctdb_context *ctdb, const char *transport)
{
	ctdb->transport = talloc_strdup(ctdb, transport);
	return 0;
}

/*
  choose the logfile location
*/
int ctdb_set_logfile(struct ctdb_context *ctdb, const char *logfile)
{
	ctdb->logfile = talloc_strdup(ctdb, logfile);
	if (ctdb->logfile != NULL) {
		int fd;
		close(1);
		fd = open(ctdb->logfile, O_WRONLY|O_APPEND|O_CREAT, 0666);
		if (fd == -1) {
			abort();
		}
		if (fd != 1) {
			dup2(fd, 1);
			close(fd);
		}
	}
	return 0;
}


/*
  set some ctdb flags
*/
void ctdb_set_flags(struct ctdb_context *ctdb, unsigned flags)
{
	ctdb->flags |= flags;
}

/*
  clear some ctdb flags
*/
void ctdb_clear_flags(struct ctdb_context *ctdb, unsigned flags)
{
	ctdb->flags &= ~flags;
}

/*
  set max acess count before a dmaster migration
*/
void ctdb_set_max_lacount(struct ctdb_context *ctdb, unsigned count)
{
	ctdb->max_lacount = count;
}

/*
  set the directory for the local databases
*/
int ctdb_set_tdb_dir(struct ctdb_context *ctdb, const char *dir)
{
	if (dir == NULL) {
		ctdb->db_directory = talloc_asprintf(ctdb, "ctdb-%u", ctdb_get_vnn(ctdb));
	} else {
		ctdb->db_directory = talloc_strdup(ctdb, dir);
	}
	if (ctdb->db_directory == NULL) {
		return -1;
	}
	return 0;
}

/*
  add a node to the list of active nodes
*/
static int ctdb_add_node(struct ctdb_context *ctdb, char *nstr)
{
	struct ctdb_node *node, **nodep;

	nodep = talloc_realloc(ctdb, ctdb->nodes, struct ctdb_node *, ctdb->num_nodes+1);
	CTDB_NO_MEMORY(ctdb, nodep);

	ctdb->nodes = nodep;
	nodep = &ctdb->nodes[ctdb->num_nodes];
	(*nodep) = talloc_zero(ctdb->nodes, struct ctdb_node);
	CTDB_NO_MEMORY(ctdb, *nodep);
	node = *nodep;

	if (ctdb_parse_address(ctdb, node, nstr, &node->address) != 0) {
		return -1;
	}
	node->ctdb = ctdb;
	node->name = talloc_asprintf(node, "%s:%u", 
				     node->address.address, 
				     node->address.port);
	/* for now we just set the vnn to the line in the file - this
	   will change! */
	node->vnn = ctdb->num_nodes;

	if (ctdb_same_address(&ctdb->address, &node->address)) {
		ctdb->vnn = node->vnn;
		node->flags |= NODE_FLAGS_CONNECTED;
	}

	ctdb->num_nodes++;

	return 0;
}

/*
  setup the node list from a file
*/
int ctdb_set_nlist(struct ctdb_context *ctdb, const char *nlist)
{
	char **lines;
	int nlines;
	int i;

	lines = file_lines_load(nlist, &nlines, ctdb);
	if (lines == NULL) {
		ctdb_set_error(ctdb, "Failed to load nlist '%s'\n", nlist);
		return -1;
	}

	for (i=0;i<nlines;i++) {
		if (ctdb_add_node(ctdb, lines[i]) != 0) {
			talloc_free(lines);
			return -1;
		}
	}
	
	talloc_free(lines);
	return 0;
}

/*
  setup the local node address
*/
int ctdb_set_address(struct ctdb_context *ctdb, const char *address)
{
	if (ctdb_parse_address(ctdb, ctdb, address, &ctdb->address) != 0) {
		return -1;
	}
	
	ctdb->name = talloc_asprintf(ctdb, "%s:%u", 
				     ctdb->address.address, 
				     ctdb->address.port);
	return 0;
}


/*
  setup the local socket name
*/
int ctdb_set_socketname(struct ctdb_context *ctdb, const char *socketname)
{
	ctdb->daemon.name = talloc_strdup(ctdb, socketname);
	return 0;
}

/*
  add a node to the list of active nodes
*/
int ctdb_set_call(struct ctdb_db_context *ctdb_db, ctdb_fn_t fn, int id)
{
	struct ctdb_registered_call *call;

	call = talloc(ctdb_db, struct ctdb_registered_call);
	call->fn = fn;
	call->id = id;

	DLIST_ADD(ctdb_db->calls, call);	
	return 0;
}

/*
  return the vnn of this node
*/
uint32_t ctdb_get_vnn(struct ctdb_context *ctdb)
{
	return ctdb->vnn;
}

/*
  return the number of nodes
*/
uint32_t ctdb_get_num_nodes(struct ctdb_context *ctdb)
{
	return ctdb->num_nodes;
}


/*
  called by the transport layer when a packet comes in
*/
void ctdb_recv_pkt(struct ctdb_context *ctdb, uint8_t *data, uint32_t length)
{
	struct ctdb_req_header *hdr = (struct ctdb_req_header *)data;
	TALLOC_CTX *tmp_ctx;

	ctdb->status.node_packets_recv++;

	/* place the packet as a child of the tmp_ctx. We then use
	   talloc_free() below to free it. If any of the calls want
	   to keep it, then they will steal it somewhere else, and the
	   talloc_free() will only free the tmp_ctx */
	tmp_ctx = talloc_new(ctdb);
	talloc_steal(tmp_ctx, hdr);

	if (length < sizeof(*hdr)) {
		ctdb_set_error(ctdb, "Bad packet length %d\n", length);
		goto done;
	}
	if (length != hdr->length) {
		ctdb_set_error(ctdb, "Bad header length %d expected %d\n", 
			       hdr->length, length);
		goto done;
	}

	if (hdr->ctdb_magic != CTDB_MAGIC) {
		ctdb_set_error(ctdb, "Non CTDB packet rejected\n");
		goto done;
	}

	if (hdr->ctdb_version != CTDB_VERSION) {
		ctdb_set_error(ctdb, "Bad CTDB version 0x%x rejected\n", hdr->ctdb_version);
		goto done;
	}

	DEBUG(3,(__location__ " ctdb request %d of type %d length %d from "
		 "node %d to %d\n", hdr->reqid, hdr->operation, hdr->length,
		 hdr->srcnode, hdr->destnode));

	switch (hdr->operation) {
	case CTDB_REQ_CALL:
		/* verify that the remote node that sent us the call
		   is running in the same generation instance as this node
		*/
		if (ctdb->vnn_map->generation != hdr->generation) {
			DEBUG(0,(__location__ " ctdb request %d of type"
				" %d length %d from node %d to %d had an"
				" invalid generation id:%d while our"
				" generation id is:%d\n", 
				hdr->reqid, hdr->operation, hdr->length, 
				hdr->srcnode, hdr->destnode, 
				ctdb->vnn_map->generation, 
				hdr->generation));
			break;
		}
		ctdb->status.count.req_call++;
		ctdb_request_call(ctdb, hdr);
		break;

	case CTDB_REPLY_CALL:
		ctdb->status.count.reply_call++;
		ctdb_reply_call(ctdb, hdr);
		break;

	case CTDB_REPLY_ERROR:
		ctdb->status.count.reply_error++;
		ctdb_reply_error(ctdb, hdr);
		break;

	case CTDB_REQ_DMASTER:
		ctdb->status.count.req_dmaster++;
		ctdb_request_dmaster(ctdb, hdr);
		break;

	case CTDB_REPLY_DMASTER:
		ctdb->status.count.reply_dmaster++;
		ctdb_reply_dmaster(ctdb, hdr);
		break;

	case CTDB_REQ_MESSAGE:
		ctdb->status.count.req_message++;
		ctdb_request_message(ctdb, hdr);
		break;

	case CTDB_REQ_FINISHED:
		ctdb->status.count.req_finished++;
		ctdb_request_finished(ctdb, hdr);
		break;

	case CTDB_REQ_CONTROL:
		ctdb->status.count.req_control++;
		ctdb_request_control(ctdb, hdr);
		break;

	case CTDB_REPLY_CONTROL:
		ctdb->status.count.reply_control++;
		ctdb_reply_control(ctdb, hdr);
		break;

	default:
		DEBUG(0,("%s: Packet with unknown operation %d\n", 
			 __location__, hdr->operation));
		break;
	}

done:
	talloc_free(tmp_ctx);
}

/*
  called by the transport layer when a packet comes in
*/
void ctdb_recv_raw_pkt(void *p, uint8_t *data, uint32_t length)
{
	struct ctdb_context *ctdb = talloc_get_type(p, struct ctdb_context);
	ctdb_recv_pkt(ctdb, data, length);
}

/*
  called by the transport layer when a node is dead
*/
static void ctdb_node_dead(struct ctdb_node *node)
{
	node->ctdb->num_connected--;
	node->flags &= ~NODE_FLAGS_CONNECTED;
	DEBUG(1,("%s: node %s is dead: %d connected\n", 
		 node->ctdb->name, node->name, node->ctdb->num_connected));
}

/*
  called by the transport layer when a node is connected
*/
static void ctdb_node_connected(struct ctdb_node *node)
{
	node->ctdb->num_connected++;
	node->flags |= NODE_FLAGS_CONNECTED;
	DEBUG(1,("%s: connected to %s - %d connected\n", 
		 node->ctdb->name, node->name, node->ctdb->num_connected));
}

/*
  wait for all nodes to be connected
*/
void ctdb_daemon_connect_wait(struct ctdb_context *ctdb)
{
	int expected = ctdb->num_nodes - 1;
	if (ctdb->flags & CTDB_FLAG_SELF_CONNECT) {
		expected++;
	}
	while (ctdb->num_connected != expected) {
		DEBUG(3,("ctdb_connect_wait: waiting for %d nodes (have %d)\n", 
			 expected, ctdb->num_connected));
		event_loop_once(ctdb->ev);
	}
	DEBUG(3,("ctdb_connect_wait: got all %d nodes\n", expected));
}

struct queue_next {
	struct ctdb_context *ctdb;
	struct ctdb_req_header *hdr;
};


/*
  trigered when a deferred packet is due
 */
static void queue_next_trigger(struct event_context *ev, struct timed_event *te, 
			       struct timeval t, void *private_data)
{
	struct queue_next *q = talloc_get_type(private_data, struct queue_next);
	ctdb_recv_pkt(q->ctdb, (uint8_t *)q->hdr, q->hdr->length);
	talloc_free(q);
}	

/*
  defer a packet, so it is processed on the next event loop
  this is used for sending packets to ourselves
 */
static void ctdb_defer_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
{
	struct queue_next *q;
	q = talloc(ctdb, struct queue_next);
	if (q == NULL) {
		DEBUG(0,(__location__ " Failed to allocate deferred packet\n"));
		return;
	}
	q->ctdb = ctdb;
	q->hdr = talloc_memdup(ctdb, hdr, hdr->length);
	if (q->hdr == NULL) {
		DEBUG(0,("Error copying deferred packet to self\n"));
		return;
	}
#if 0
	/* use this to put packets directly into our recv function */
	ctdb_recv_pkt(q->ctdb, (uint8_t *)q->hdr, q->hdr->length);
	talloc_free(q);
#else
	event_add_timed(ctdb->ev, q, timeval_zero(), queue_next_trigger, q);
#endif
}

/*
  queue a packet or die
*/
void ctdb_queue_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
{
	struct ctdb_node *node;
	ctdb->status.node_packets_sent++;

	if (!ctdb_validate_vnn(ctdb, hdr->destnode)) {
	  	DEBUG(0,(__location__ " cant send to node %u that does not exist\n", 
			 hdr->destnode));
		return;
	}

	node = ctdb->nodes[hdr->destnode];

	if (hdr->destnode == ctdb->vnn && !(ctdb->flags & CTDB_FLAG_SELF_CONNECT)) {
		ctdb_defer_packet(ctdb, hdr);
	} else if (ctdb->methods->queue_pkt(node, (uint8_t *)hdr, hdr->length) != 0) {
		ctdb_fatal(ctdb, "Unable to queue packet\n");
	}
}


static const struct ctdb_upcalls ctdb_upcalls = {
	.recv_pkt       = ctdb_recv_pkt,
	.node_dead      = ctdb_node_dead,
	.node_connected = ctdb_node_connected
};

/*
  initialise the ctdb daemon. 

  NOTE: In current code the daemon does not fork. This is for testing purposes only
  and to simplify the code.
*/
struct ctdb_context *ctdb_init(struct event_context *ev)
{
	struct ctdb_context *ctdb;

	ctdb = talloc_zero(ev, struct ctdb_context);
	ctdb->ev = ev;
	ctdb->upcalls = &ctdb_upcalls;
	ctdb->idr = idr_init(ctdb);
	ctdb->max_lacount = CTDB_DEFAULT_MAX_LACOUNT;

	return ctdb;
}