samba-mirror/ctdb/server/ctdb_server.c

/* 
   ctdb main protocol code

   Copyright (C) Andrew Tridgell  2006

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#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 recovery lock file
*/
int ctdb_set_recovery_lock_file(struct ctdb_context *ctdb, const char *file)
{
	ctdb->recovery_lock_file = talloc_strdup(ctdb, file);
	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 && strcmp(logfile, "-") != 0) {
		int fd;
		fd = open(ctdb->logfile, O_WRONLY|O_APPEND|O_CREAT, 0666);
		if (fd == -1) {
			printf("Failed to open logfile %s\n", ctdb->logfile);
			abort();
		}
		close(1);
		close(2);
		if (fd != 1) {
			dup2(fd, 1);
			close(fd);
		}
		/* also catch stderr of subcommands to the log file */
		dup2(1, 2);
	}
	return 0;
}


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

/*
  set the directory for the persistent databases
*/
int ctdb_set_tdb_dir_persistent(struct ctdb_context *ctdb, const char *dir)
{
	ctdb->db_directory_persistent = talloc_strdup(ctdb, dir);
	if (ctdb->db_directory_persistent == 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);
	/* this assumes that the nodes are kept in sorted order, and no gaps */
	node->pnn = ctdb->num_nodes;

	/* nodes start out disconnected */
	node->flags |= NODE_FLAGS_DISCONNECTED;

	if (ctdb->address.address &&
	    ctdb_same_address(&ctdb->address, &node->address)) {
		ctdb->pnn = node->pnn;
		node->flags &= ~NODE_FLAGS_DISCONNECTED;
	}

	ctdb->num_nodes++;
	node->dead_count = 0;

	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;

	talloc_free(ctdb->node_list_file);
	ctdb->node_list_file = talloc_strdup(ctdb, nlist);

	lines = file_lines_load(nlist, &nlines, ctdb);
	if (lines == NULL) {
		ctdb_set_error(ctdb, "Failed to load nlist '%s'\n", nlist);
		return -1;
	}
	while (nlines > 0 && strcmp(lines[nlines-1], "") == 0) {
		nlines--;
	}

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

	/* initialize the vnn mapping table now that we have num_nodes setup */
	ctdb->vnn_map = talloc(ctdb, struct ctdb_vnn_map);
	CTDB_NO_MEMORY(ctdb, ctdb->vnn_map);

	ctdb->vnn_map->generation = INVALID_GENERATION;
	ctdb->vnn_map->size = ctdb->num_nodes;
	ctdb->vnn_map->map = talloc_array(ctdb->vnn_map, uint32_t, ctdb->vnn_map->size);
	CTDB_NO_MEMORY(ctdb, ctdb->vnn_map->map);

	for(i=0;i<ctdb->vnn_map->size;i++) {
		ctdb->vnn_map->map[i] = i;
	}
	
	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;
}


/*
  return the number of active nodes
*/
uint32_t ctdb_get_num_active_nodes(struct ctdb_context *ctdb)
{
	int i;
	uint32_t count=0;
	for (i=0;i<ctdb->vnn_map->size;i++) {
		struct ctdb_node *node = ctdb->nodes[ctdb->vnn_map->map[i]];
		if (!(node->flags & NODE_FLAGS_INACTIVE)) {
			count++;
		}
	}
	return count;
}


/*
  called when we need to process a packet. This can be a requeued packet
  after a lockwait, or a real packet from another node
*/
void ctdb_input_pkt(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
{
	TALLOC_CTX *tmp_ctx;

	/* 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);

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

	switch (hdr->operation) {
	case CTDB_REQ_CALL:
	case CTDB_REPLY_CALL:
	case CTDB_REQ_DMASTER:
	case CTDB_REPLY_DMASTER:
		/* we dont allow these calls when banned */
		if (ctdb->nodes[ctdb->pnn]->flags & NODE_FLAGS_BANNED) {
			DEBUG(0,(__location__ " ctdb operation %u"
				" request %u"
				" length %u from node %u to %u while node"
				" is banned\n",
				 hdr->operation, hdr->reqid,
				 hdr->length, 
				 hdr->srcnode, hdr->destnode));
			goto done;
		}

		/* for ctdb_call inter-node operations 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 operation %u"
				" request %u"
				" length %u from node %u to %u had an"
				" invalid generation id:%u while our"
				" generation id is:%u\n", 
				 hdr->operation, hdr->reqid,
				 hdr->length, 
				 hdr->srcnode, hdr->destnode, 
				 hdr->generation, ctdb->vnn_map->generation));
			goto done;
		}
	}

	switch (hdr->operation) {
	case CTDB_REQ_CALL:
		ctdb->statistics.node.req_call++;
		ctdb_request_call(ctdb, hdr);
		break;

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

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

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

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

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

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

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

	case CTDB_REQ_KEEPALIVE:
		ctdb->statistics.keepalive_packets_recv++;
		break;

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

done:
	talloc_free(tmp_ctx);
}


/*
  called by the transport layer when a node is dead
*/
void ctdb_node_dead(struct ctdb_node *node)
{
	if (node->flags & NODE_FLAGS_DISCONNECTED) {
		DEBUG(1,("%s: node %s is already marked disconnected: %u connected\n", 
			 node->ctdb->name, node->name, 
			 node->ctdb->num_connected));
		return;
	}
	node->ctdb->num_connected--;
	node->flags |= NODE_FLAGS_DISCONNECTED;
	node->rx_cnt = 0;
	node->dead_count = 0;
	DEBUG(1,("%s: node %s is dead: %u connected\n", 
		 node->ctdb->name, node->name, node->ctdb->num_connected));
	ctdb_daemon_cancel_controls(node->ctdb, node);
}

/*
  called by the transport layer when a node is connected
*/
void ctdb_node_connected(struct ctdb_node *node)
{
	if (!(node->flags & NODE_FLAGS_DISCONNECTED)) {
		DEBUG(1,("%s: node %s is already marked connected: %u connected\n", 
			 node->ctdb->name, node->name, 
			 node->ctdb->num_connected));
		return;
	}
	node->ctdb->num_connected++;
	node->dead_count = 0;
	node->flags &= ~NODE_FLAGS_DISCONNECTED;
	DEBUG(1,("%s: connected to %s - %u connected\n", 
		 node->ctdb->name, node->name, node->ctdb->num_connected));
}

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_input_pkt(q->ctdb, q->hdr);
	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_input_pkt(q->ctdb, q->hdr);
#else
	event_add_timed(ctdb->ev, q, timeval_zero(), queue_next_trigger, q);
#endif
}


/*
  broadcast a packet to all nodes
*/
static void ctdb_broadcast_packet_all(struct ctdb_context *ctdb, 
				      struct ctdb_req_header *hdr)
{
	int i;
	for (i=0;i<ctdb->num_nodes;i++) {
		hdr->destnode = ctdb->nodes[i]->pnn;
		ctdb_queue_packet(ctdb, hdr);
	}
}

/*
  broadcast a packet to all nodes in the current vnnmap
*/
static void ctdb_broadcast_packet_vnnmap(struct ctdb_context *ctdb, 
					 struct ctdb_req_header *hdr)
{
	int i;
	for (i=0;i<ctdb->vnn_map->size;i++) {
		hdr->destnode = ctdb->vnn_map->map[i];
		ctdb_queue_packet(ctdb, hdr);
	}
}

/*
  broadcast a packet to all connected nodes
*/
static void ctdb_broadcast_packet_connected(struct ctdb_context *ctdb, 
					    struct ctdb_req_header *hdr)
{
	int i;
	for (i=0;i<ctdb->num_nodes;i++) {
		if (!(ctdb->nodes[i]->flags & NODE_FLAGS_DISCONNECTED)) {
			hdr->destnode = ctdb->nodes[i]->pnn;
			ctdb_queue_packet(ctdb, hdr);
		}
	}
}

/*
  queue a packet or die
*/
void ctdb_queue_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
{
	struct ctdb_node *node;

	switch (hdr->destnode) {
	case CTDB_BROADCAST_ALL:
		ctdb_broadcast_packet_all(ctdb, hdr);
		return;
	case CTDB_BROADCAST_VNNMAP:
		ctdb_broadcast_packet_vnnmap(ctdb, hdr);
		return;
	case CTDB_BROADCAST_CONNECTED:
		ctdb_broadcast_packet_connected(ctdb, hdr);
		return;
	}

	ctdb->statistics.node_packets_sent++;

	if (!ctdb_validate_pnn(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->pnn) {
		ctdb_defer_packet(ctdb, hdr);
	} else {
		node->tx_cnt++;
		if (ctdb->methods->queue_pkt(node, (uint8_t *)hdr, hdr->length) != 0) {
			ctdb_fatal(ctdb, "Unable to queue packet\n");
		}
	}
}