connections.c

/**
 *  Copyright 2009-2014 MongoDB, Inc.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
#include <string.h>
#include "types.h"
#include "utils.h"
#include "parse.h"
#include "manager.h"
#include "connections.h"
#include "str.h"
#include "contrib/strndup.h"
#include "bson_helpers.h"
#include "contrib/md5.h"
#include "mini_bson.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#define INT_32  4
#define FLAGS   0

#define MONGO_REPLY_FLAG_QUERY_FAILURE 0x02

/* Helper functions */
int mongo_connection_get_reqid(mongo_connection *con)
{
	con->last_reqid++;
	return con->last_reqid;
}

static void mongo_connection_destroy_tags(mongo_connection *con)
{
	int i;

	for (i = 0; i < con->tag_count; i++) {
		free(con->tags[i]);
	}
	if (con->tags) {
		free(con->tags);
	}

	con->tag_count = 0;
	con->tags = NULL;
}

mongo_connection *mongo_connection_create(mongo_con_manager *manager, char *hash, mongo_server_def *server_def, mongo_server_options *options, char **error_message)
{
	mongo_connection *tmp;

	/* Init struct */
	tmp = malloc(sizeof(mongo_connection));
	memset(tmp, 0, sizeof(mongo_connection));
	tmp->last_reqid = rand();
	tmp->connection_type = MONGO_NODE_STANDALONE;
	tmp->connected = 0;

	/* Default server options */
	/* If we don't know the version, assume 1.8.0 */
	tmp->version.major = 1;
	tmp->version.minor = 8;
	tmp->version.mini  = 0;
	tmp->version.build = 0;
	tmp->max_bson_size = MONGO_CONNECTION_DEFAULT_MAX_BSON_SIZE;
	tmp->max_message_size = MONGO_CONNECTION_DEFAULT_MAX_MESSAGE_SIZE;
	tmp->max_write_batch_size = MONGO_CONNECTION_DEFAULT_MAX_WRITE_BATCH_SIZE;
	tmp->min_wire_version = MONGO_CONNECTION_DEFAULT_MIN_WIRE_VERSION;
	tmp->max_wire_version = MONGO_CONNECTION_DEFAULT_MAX_WIRE_VERSION;

	/* Store hash */
	tmp->hash = strdup(hash);

	/* Connect */
	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "connection_create: creating new connection for %s:%d", server_def->host, server_def->port);
	tmp->socket = manager->connect(manager, server_def, options, error_message);
	if (!tmp->socket) {
		mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "connection_create: error while creating connection for %s:%d: %s", server_def->host, server_def->port, *error_message);
		mongo_manager_blacklist_register(manager, tmp);
		free(tmp->hash);
		free(tmp);
		return NULL;
	}

	return tmp;
}

void mongo_connection_destroy(mongo_con_manager *manager, void *data, int why)
{
	int current_pid, connection_pid;
	mongo_connection *con = (mongo_connection *)data;

	current_pid = getpid();
	connection_pid = mongo_server_hash_to_pid(con->hash);

	/* Only close the connection if it matches the current PID */
	if (current_pid == connection_pid) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "mongo_connection_destroy: Destroying connection object for %s", con->hash);

		if (con->socket) {
			mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "mongo_connection_destroy: Closing socket for %s.", con->hash);
			manager->close(con, why);
			con->socket = NULL;

			mongo_connection_destroy_tags(con);

			if (con->cleanup_list) {
				mongo_connection_deregister_callback *ptr = con->cleanup_list;
				mongo_connection_deregister_callback *prev;
				do {
					if (ptr->callback_data) {
						ptr->mongo_cleanup_cb(ptr->callback_data);
					}

					if (!ptr->next) {
						free(ptr);
						ptr = NULL;
						break;
					}
					prev = ptr;
					ptr = ptr->next;
					free(prev);
					prev = NULL;
				} while (1);
				con->cleanup_list = NULL;
			}
			free(con->hash);
			free(con);
		}
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "mongo_connection_destroy: The process pid (%d) for %s doesn't match the connection pid (%d).", current_pid, con->hash, connection_pid);
	}
}

#define MONGO_REPLY_HEADER_SIZE 36

/* Returns 1 if it worked, and 0 if it didn't. If 0 is returned, *error_message
 * is set and must be free()d. On success *data_buffer is set and must be free()d */
static int mongo_connect_send_packet(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, mcon_str *packet, char **data_buffer, char **error_message)
{
	int            read;
	uint32_t       data_size;
	char           reply_buffer[MONGO_REPLY_HEADER_SIZE];
	uint32_t       flags; /* To check for query reply status */

	/* Send and wait for reply */
	if (manager->send(con, options, packet->d, packet->l, error_message) == -1) {
		mcon_str_ptr_dtor(packet);
		/* Error already populated */
		return 0;
	}
	mcon_str_ptr_dtor(packet);
	read = manager->recv_header(con, options, con->connected ? options->socketTimeoutMS : options->connectTimeoutMS, reply_buffer, MONGO_REPLY_HEADER_SIZE, error_message);
	if (read < 0) {
		/* Error already populated */
		return 0;
	}

	mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "send_packet: read from header: %d", read);
	if (read < MONGO_REPLY_HEADER_SIZE) {
		*error_message = malloc(256);
		snprintf(*error_message, 256, "send_package: the amount of bytes read (%d) is less than the header size (%d)", read, MONGO_REPLY_HEADER_SIZE);
		return 0;
	}

	/* Read result flags */
	flags = MONGO_32(*(int*)(reply_buffer + sizeof(int32_t) * 4));

	/* Read the rest of the data */
	data_size = MONGO_32(*(int*)(reply_buffer)) - MONGO_REPLY_HEADER_SIZE;
	mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "send_packet: data_size: %d", data_size);

	/* Check size limits */
	if (con->max_bson_size && data_size > (uint32_t)con->max_bson_size) {
		*error_message = malloc(256);
		snprintf(*error_message, 256, "send_package: data corruption: the returned size of the reply (%d) is larger than the maximum allowed size (%d)", data_size, con->max_bson_size);
		return 0;
	}

	/* Read data */
	*data_buffer = malloc(data_size + 1);
	if (manager->recv_data(con, options, con->connected ? options->socketTimeoutMS : options->connectTimeoutMS, *data_buffer, data_size, error_message) <= 0) {
		free(*data_buffer);
		/* Error already populated */
		return 0;
	}

	/* Check for a query error */
	if (flags & MONGO_REPLY_FLAG_QUERY_FAILURE) {
		char *ptr = *data_buffer + sizeof(int32_t); /* Skip the length */
		char *err;
		int32_t code;

		/* Find the error */
		if (bson_find_field_as_string(ptr, "$err", &err)) {
			*error_message = malloc(256 + strlen(err));

			if (bson_find_field_as_int32(ptr, "code", &code)) {
				snprintf(*error_message, 256 + strlen(err), "send_package: the query returned a failure: %s (code: %d)", err, code);
			} else {
				snprintf(*error_message, 256 + strlen(err), "send_package: the query returned a failure: %s", err);
			}
		} else {
			*error_message = strdup("send_package: the query returned an unknown error");
		}

		free(*data_buffer);
		return 0;
	}

	return 1;
}

int mongo_connection_ping_check(mongo_con_manager *manager, int last_ping, struct timeval *start)
{
	gettimeofday(start, NULL);
	if ((last_ping + manager->ping_interval) > start->tv_sec) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "is_ping: skipping: last ran at %ld, now: %ld, time left: %ld", last_ping, start->tv_sec, last_ping + manager->ping_interval - start->tv_sec);
		return 0;
	}
	return 1;
}

/* Sends a ping command to the server and stores the result.
 *
 * Returns 1 when it worked, and 0 when an error was encountered. */
int mongo_connection_ping(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char **error_message)
{
	mcon_str      *packet;
	struct timeval start, end;
	char          *data_buffer;

	/* If we haven't hit the ping_interval yet, then there is no need to do a roundtrip to the server */
	if (!mongo_connection_ping_check(manager, con->last_ping, &start)) {
		return 1;
	}
	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "is_ping: pinging %s", con->hash);
	packet = bson_create_ping_packet(con);
	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return 0;
	}
	gettimeofday(&end, NULL);
	free(data_buffer);

	con->last_ping = end.tv_sec;
	con->ping_ms = (end.tv_sec - start.tv_sec) * 1000 + (end.tv_usec - start.tv_usec) / 1000;
	if (con->ping_ms < 0) { /* some clocks do weird stuff */
		con->ping_ms = 0;
	}

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "is_ping: last pinged at %ld; time: %dms", con->last_ping, con->ping_ms);

	return 1;
}

/* Sends an ismaster command to the server and returns an array of new
 * connectable nodes
 *
 * Returns:
 * 0: when an error occurred
 * 1: when is master was run and worked
 * 2: when is master wasn't run due to the time-out limit
 * 3: when it all worked, but we need to remove the seed host (due to its name
 *    not being what the server thought it is) - in that case, the server in
 *    the last argument is changed
 * 4: when the call worked, but wasn't within our supported wire version range */
int mongo_connection_ismaster(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char **repl_set_name, int *nr_hosts, char ***found_hosts, char **error_message, mongo_server_def *server)
{
	mcon_str      *packet;
	char          *data_buffer;
	int32_t        max_bson_size = 0, max_message_size = 0, max_write_batch_size = 0;
	int32_t        min_wire_version = 0, max_wire_version = 0;
	char          *set = NULL;      /* For replicaset in return */
	char          *hosts, *passives = NULL, *ptr, *string;
	char          *msg; /* If set and its value is "isdbgrid", it signals we connected to a mongos */
	unsigned char  ismaster = 0, secondary = 0, arbiter = 0;
	char          *connected_name, *we_think_we_are;
	char          *tags;
	struct timeval now;
	int            retval = 1;

	gettimeofday(&now, NULL);
	if (((server ? con->last_replcheck : con->last_ismaster) + manager->ismaster_interval) > now.tv_sec) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: skipping: last ran at %ld, now: %ld, time left: %ld", con->last_ismaster, now.tv_sec, con->last_ismaster + manager->ismaster_interval - now.tv_sec);
		return 2;
	}

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "ismaster: start");
	packet = bson_create_ismaster_packet(con);

	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return 0;
	}

	/* Find data fields */
	ptr = data_buffer + sizeof(int32_t); /* Skip the length */

	/* Find [min|max]WireVersion */
	if (bson_find_field_as_int32(ptr, "minWireVersion", &min_wire_version)) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: setting minWireVersion to %d", min_wire_version);
		con->min_wire_version = min_wire_version;
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: can't find minWireVersion, defaulting to %d", con->min_wire_version);
	}

	if (bson_find_field_as_int32(ptr, "maxWireVersion", &max_wire_version)) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: setting maxWireVersion to %d", max_wire_version);
		con->max_wire_version = max_wire_version;
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: can't find maxWireVersion, defaulting to %d", con->max_wire_version);
	}

	if (!manager->supports_wire_version(con->min_wire_version, con->max_wire_version, error_message)) {
		/* Error message set by supports_wire_version */
		free(data_buffer);
		return 4;
	}

	/* Find max bson size */
	if (bson_find_field_as_int32(ptr, "maxBsonObjectSize", &max_bson_size)) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: setting maxBsonObjectSize to %d", max_bson_size);
		con->max_bson_size = max_bson_size;
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: can't find maxBsonObjectSize, defaulting to %d", con->max_bson_size);
	}

	/* Find max message size */
	if (bson_find_field_as_int32(ptr, "maxMessageSizeBytes", &max_message_size)) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: setting maxMessageSizeBytes to %d", max_message_size);
		con->max_message_size = max_message_size;
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: can't find maxMessageSizeBytes, defaulting to %d", con->max_message_size);
	}

	/* Find max batch item size */
	if (bson_find_field_as_int32(ptr, "maxWriteBatchSize", &max_write_batch_size)) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: setting maxWriteBatchSize to %d", max_write_batch_size);
		con->max_write_batch_size = max_write_batch_size;
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: can't find maxWriteBatchSize, defaulting to %d", con->max_write_batch_size);
	}


	/* Check for flags */
	bson_find_field_as_bool(ptr, "ismaster", &ismaster);
	bson_find_field_as_bool(ptr, "secondary", &secondary);
	bson_find_field_as_bool(ptr, "arbiterOnly", &arbiter);
	bson_find_field_as_string(ptr, "setName", &set);

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "ismaster: set name: %s, ismaster: %d, secondary: %d, is_arbiter: %d", set, ismaster, secondary, arbiter);

	/* Set connection type depending on flags */
	if (ismaster) {
		/* Find msg and whether it contains "isdbgrid" */
		if (bson_find_field_as_string(ptr, "msg", (char**) &msg) && strcmp(msg, "isdbgrid") == 0) {
			mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: msg contains 'isdbgrid' - we're connected to a mongos");
			con->connection_type = MONGO_NODE_MONGOS;
		} else if(set) {
			con->connection_type = MONGO_NODE_PRIMARY;
		} else {
			con->connection_type = MONGO_NODE_STANDALONE;
		}
	} else if (secondary) {
		con->connection_type = MONGO_NODE_SECONDARY;
	} else if (arbiter) {
		con->connection_type = MONGO_NODE_ARBITER;
	} else if (!set) {
		/* If there is no set, we assume this is an "old style" "slave" node */
		con->connection_type = MONGO_NODE_SECONDARY;
	} else {
		con->connection_type = MONGO_NODE_INVALID;
	}

	if (con->connection_type == MONGO_NODE_INVALID) {
		*error_message = strdup("ismaster: got unknown node type");
		free(data_buffer);
		return 0;
	}

	/* Unset tags that could have been previously set */
	mongo_connection_destroy_tags(con);

	/* Find read preferences tags */
	if (bson_find_field_as_document(ptr, "tags", (char**) &tags)) {
		char *it, *name, *value;
		int   length;

		it = tags;

		while (bson_array_find_next_string(&it, &name, &value)) {
			con->tags = realloc(con->tags, (con->tag_count + 1) * sizeof(char*));
			length = strlen(name) + strlen(value) + 2;
			con->tags[con->tag_count] = malloc(length);
			snprintf(con->tags[con->tag_count], length, "%s:%s", name, value);
			free(name);
			mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: added tag %s", con->tags[con->tag_count]);
			con->tag_count++;
		}
	}

	/* If we get passed in a server it means we want to validate this node against it, along with discovery ReplicaSet stuff */
	if (!server) {
		goto done;
	}

	/* We find out whether the machine we connected too, is actually the
	 * one we thought we were connecting too */
	/* MongoDB 1.8.x doesn't have the "me" field.
	 * The replicaset verification is done next step (setName). */
	if (bson_find_field_as_string(ptr, "me", &connected_name)) {
		we_think_we_are = mongo_server_hash_to_server(con->hash);
		if (strcmp(connected_name, we_think_we_are) == 0) {
			mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: the server name matches what we thought it'd be (%s).", we_think_we_are);
		} else {
			mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "ismaster: the server name (%s) did not match with what we thought it'd be (%s).", connected_name, we_think_we_are);
			/* We reset the name as the server responded with a different name than
			 * what we thought it was */
			free(server->host);
			server->host = mcon_strndup(connected_name, strchr(connected_name, ':') - connected_name);
			server->port = atoi(strchr(connected_name, ':') + 1);
			retval = 3;
		}
		free(we_think_we_are);
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "Can't find 'me' in ismaster response, possibly not a replicaset (%s)", mongo_server_hash_to_server(con->hash));
	}

	/* Do replica set name test */
	if (!set) {
		char *errmsg = NULL;
		bson_find_field_as_string(ptr, "errmsg", &errmsg);
		if (errmsg) {
			*error_message = strdup(errmsg);
		} else {
			*error_message = strdup("Not a replicaset member");
		}
		free(data_buffer);
		return 0;
	} else if (*repl_set_name) {
		if (strcmp(set, *repl_set_name) != 0) {
			struct mcon_str *tmp;

			mcon_str_ptr_init(tmp);
			mcon_str_add(tmp, "Host does not match replicaset name. Expected: ", 0);
			mcon_str_add(tmp, *repl_set_name, 0);
			mcon_str_add(tmp, "; Found: ", 0);
			mcon_str_add(tmp, set, 0);

			*error_message = strdup(tmp->d);
			mcon_str_ptr_dtor(tmp);

			free(data_buffer);
			return 0;
		} else {
			mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "ismaster: the found replicaset name matches the expected one (%s).", set);
		}
	} else if (*repl_set_name == NULL) {
		/* This can happen, in case the replicaset name was not given, but just
		 * bool(true) (or string("1")) in the connection options. */
		mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "ismaster: the replicaset name is not set, so we're using %s.", set);
		*repl_set_name = strdup(set);
	}

	/* If the server definition has not set the repl_set_name member yet, set it here */
	if (!server->repl_set_name) {
		server->repl_set_name = strdup(set);
	}

	/* Find all hosts */
	bson_find_field_as_array(ptr, "hosts", &hosts);
	bson_find_field_as_array(ptr, "passives", &passives);
	*nr_hosts = 0;

	/* Iterate over the "hosts" document */
	ptr = hosts;
	while (bson_array_find_next_string(&ptr, NULL, &string)) {
		(*nr_hosts)++;
		*found_hosts = realloc(*found_hosts, (*nr_hosts) * sizeof(char*));
		(*found_hosts)[*nr_hosts-1] = strdup(string);
		mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "found host: %s", string);
	}

	/* Iterate over the "passives" document (priority=0) */
	if (passives) {
		ptr = passives;
		while (bson_array_find_next_string(&ptr, NULL, &string)) {
			(*nr_hosts)++;
			*found_hosts = realloc(*found_hosts, (*nr_hosts) * sizeof(char*));
			(*found_hosts)[*nr_hosts-1] = strdup(string);
			mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "found host: %s (passive)", string);
		}
	}

	con->last_replcheck = now.tv_sec;

done:
	free(data_buffer);

	con->last_ismaster = now.tv_sec;
	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "ismaster: last ran at %ld", con->last_ismaster);

	return retval;
}

/* Sends an buildInfo command to the server to find server version
 *
 * Returns 1 when it worked, and 0 when an error was encountered. */
int mongo_connection_get_server_version(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char **error_message)
{
	mcon_str      *packet;
	char          *data_buffer;
	char          *ptr;
	char          *version_array;

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "get_server_version: start");
	packet = bson_create_buildinfo_packet(con);

	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return 0;
	}

	/* Find data fields */
	ptr = data_buffer + sizeof(int32_t); /* Skip the length */

	/* Find read preferences tags */
	if (bson_find_field_as_array(ptr, "versionArray", (char**) &version_array)) {
		char *it;

		it = version_array;

		if (bson_array_find_next_int32(&it, NULL, &con->version.major)) {
			if (bson_array_find_next_int32(&it, NULL, &con->version.minor)) {
				if (bson_array_find_next_int32(&it, NULL, &con->version.mini)) {
					if (bson_array_find_next_int32(&it, NULL, &con->version.build)) {
						mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "get_server_version: server version: %d.%d.%d (%d)", con->version.major, con->version.minor, con->version.mini, con->version.build);
					}
				}
			}
		}
	} else {
		mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "get_server_flags: can't find version information, defaulting to %d.%d.%d (%d)", con->version.major, con->version.minor, con->version.mini, con->version.build);
	}

	free(data_buffer);

	return 1;
}

/* Sends a getnonce command to the server for authentication
 *
 * Returns the nonsense when it worked, or NULL if it didn't. */
char *mongo_connection_getnonce(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char **error_message)
{
	mcon_str      *packet;
	char          *data_buffer;
	char          *ptr;
	char          *nonce;
	char          *retval = NULL;

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "getnonce: start");
	packet = bson_create_getnonce_packet(con);

	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return NULL;
	}

	/* Find data fields */
	ptr = data_buffer + sizeof(int32_t); /* Skip the length */

	/* Find getnonce */
	if (bson_find_field_as_string(ptr, "nonce", &nonce)) {
		mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "getnonce: found nonce '%s'", nonce);
	} else {
		*error_message = strdup("Couldn't find the nonce field");
		free(data_buffer);
		return NULL;
	}

	retval = strdup(nonce);

	free(data_buffer);

	return retval;
}

/**
 * Authenticates a connection
 *
 * Returns:
 * 0: when authentication (or getting nonce) fails, or unknown auth mechanism is set - with the error_message set
 * 1: when it worked
 * 2: when no need to authenticate (i.e. no credentials provided)
 */
int mongo_connection_authenticate(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, mongo_server_def *server_def, char **error_message)
{
	int   retval = 0;

	switch (server_def->mechanism) {
		case MONGO_AUTH_MECHANISM_MONGODB_DEFAULT:
		case MONGO_AUTH_MECHANISM_MONGODB_CR: {
			char *nonce;
			if (!server_def->db || !server_def->username || !server_def->password) {
				return 2;
			}

			nonce = mongo_connection_getnonce(manager, con, options, error_message);
			if (!nonce) {
				*error_message = strdup("Nonce could not be created");
				return 0;
			}

			retval = mongo_connection_authenticate_mongodb_cr(manager, con, options, server_def->authdb ? server_def->authdb : server_def->db, server_def->username, server_def->password, nonce, error_message);
			free(nonce);
		} break;

		case MONGO_AUTH_MECHANISM_MONGODB_X509:
			retval = mongo_connection_authenticate_mongodb_x509(manager, con, options, server_def->authdb ? server_def->authdb : server_def->db, server_def->username, error_message);
			break;

		default:
			*error_message = strdup("Only MongoDB-CR and MONGODB-X509 authentication mechanisms is supported by this build");
			return 0;
	}

	return retval;
}

char *mongo_authenticate_hash_user_password(char *username, char *password)
{
	char          *salted;
	int            length;
	char          *hash;

	/* Calculate hash=md5(${username}:mongo:${password}) */
	length = strlen(username) + 7 + strlen(password) + 1;
	salted = malloc(length);
	snprintf(salted, length, "%s:mongo:%s", username, password);
	hash = mongo_util_md5_hex(salted, length - 1); /* -1 to chop off \0 */
	free(salted);

	return hash;
}

/**
 * Authenticates a connection using MONGODB-CR
 *
 * Returns:
 * 0: when it didn't work - with the error_message set.
 * 1: when it worked
 */
int mongo_connection_authenticate_mongodb_cr(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char *database, char *username, char *password, char *nonce, char **error_message)
{
	mcon_str      *packet;
	char          *salted;
	int            length;
	char          *hash, *key;

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "authenticate: start");

	hash = mongo_authenticate_hash_user_password(username, password);
	mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "authenticate: hash=md5(%s:mongo:%s) = %s", username, password, hash);

	/* Calculate key=md5(${nonce}${username}${hash}) */
	length = strlen(nonce) + strlen(username) + strlen(hash) + 1;
	salted = malloc(length);
	snprintf(salted, length, "%s%s%s", nonce, username, hash);
	key = mongo_util_md5_hex(salted, length - 1); /* -1 to chop off \0 */
	free(salted);
	mongo_manager_log(manager, MLOG_CON, MLOG_FINE, "authenticate: key=md5(%s%s%s) = %s", nonce, username, hash, key);

	/* BC: Do not send MONGODB-CR as mechanism, won't work on older mongod */
	packet = bson_create_authenticate_packet(con, NULL, database, username, nonce, key);

	free(hash);
	free(key);

	return mongo_connection_authenticate_cmd(manager, con, options, database, username, packet, error_message);
}


/**
 * Authenticates a connection using MONGODB-X509
 *
 * Returns:
 * 0: when it didn't work - with the error_message set.
 * 1: when it worked
 */
int mongo_connection_authenticate_mongodb_x509(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char *database, char *username, char **error_message)
{
	mcon_str      *packet;

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "authenticate (X509): start");

	packet = bson_create_authenticate_packet(con, "MONGODB-X509", database, username, NULL, NULL);

	return mongo_connection_authenticate_cmd(manager, con, options, database, username, packet, error_message);
}

/**
 * Sends the db.authenticate() command packet
 *
 * Returns:
 * 0: when it didn't work - with the error_message set (extracted from the 'errmsg' field if possible)
 * 1: when it worked
 */
int mongo_connection_authenticate_cmd(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, char *database, char *username, mcon_str *packet, char **error_message)
{
	char          *data_buffer, *errmsg;
	double         ok;
	char          *ptr;

	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return 0;
	}

	/* Find data fields */
	ptr = data_buffer + sizeof(int32_t); /* Skip the length */

	/* Find errmsg */
	if (bson_find_field_as_double(ptr, "ok", &ok)) {
		if (ok > 0) {
			mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "authentication successful");
		} else {
			mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "authentication failed");
		}
	}
	if (bson_find_field_as_string(ptr, "errmsg", &errmsg)) {
		*error_message = malloc(256);
		snprintf(*error_message, 256, "Authentication failed on database '%s' with username '%s': %s", database, username, errmsg);
		free(data_buffer);
		return 0;
	}

	free(data_buffer);

	return 1;
}

int mongo_connection_authenticate_saslstart(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, mongo_server_def *server_def, char *mechanism, char *payload, unsigned int payload_len, char **out_payload, int *out_payload_len, int32_t *out_conversation_id, char **error_message)
{
	mcon_str      *packet;
	char          *data_buffer;
	char          *ptr;
	char          *smechanism;
	double         ok;
	char          *errmsg;

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "connection_authenticate_sasl: Starting SASL authentication process to '%s'", con->hash);

	if (server_def->mechanism == MONGO_AUTH_MECHANISM_MONGODB_CR) {
		*error_message = strdup("Invalid authentication mechanism. Expected SASL mechanism, got MongoDB-CR");
		return 0;
	}

	packet = bson_create_saslstart_packet(con, server_def->authdb ? server_def->authdb : server_def->db, mechanism, payload, payload_len);

	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return 0;
	}

	/* Find data fields */
	ptr = data_buffer + sizeof(int32_t); /* Skip the length */

	if (bson_find_field_as_double(ptr, "ok", &ok)) {
		if (ok > 0) {
			mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "SASL request successful");
		} else {
			mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "SASL request failed");
			if (bson_find_field_as_string(ptr, "errmsg", &errmsg)) {
				*error_message = malloc(256);
				snprintf(*error_message, 256, "SASL Authentication failed on database '%s': %s", server_def->db, errmsg);
			} else {
				*error_message = "SASL Authentication failed";
			}
			if (bson_find_field_as_document(ptr, "supportedMechanisms", (char**) &smechanism)) {
				/* TODO: Retrieve a list of supportedMechanisms and return it somehow */
			}

			free(data_buffer);
			return 0;
		}
	}

	if (bson_find_field_as_int32(ptr, "conversationId", out_conversation_id)) {
		bson_find_field_as_stringl(ptr, "payload", out_payload, out_payload_len, 1);
	}
	free(data_buffer);

	return 1;
}

int mongo_connection_authenticate_saslcontinue(mongo_con_manager *manager, mongo_connection *con, mongo_server_options *options, mongo_server_def *server_def, int32_t conversation_id, char *payload, int payload_len, char **out_payload, int *out_payload_len, unsigned char *done, char **error_message)
{
	mcon_str      *packet;
	char          *data_buffer;
	char          *ptr;
	double         ok;
	char          *errmsg;
	int32_t       out_conversation_id;

	mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "connection_authenticate_saslcontinue: continuing SASL authentication to '%s'", con->hash);

	/*  GSSAPI=$external, all other use the actual dbname */
	packet = bson_create_saslcontinue_packet(con, server_def->authdb ? server_def->authdb : server_def->db, conversation_id, payload, payload_len);

	if (!mongo_connect_send_packet(manager, con, options, packet, &data_buffer, error_message)) {
		return 0;
	}

	/* Find data fields */
	ptr = data_buffer + sizeof(int32_t); /* Skip the length */

	if (bson_find_field_as_double(ptr, "ok", &ok)) {
		if (ok > 0) {
			mongo_manager_log(manager, MLOG_CON, MLOG_INFO, "SASL continue successful");
		} else {
			mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "SASL continue failed");
			if (bson_find_field_as_string(ptr, "errmsg", &errmsg)) {
				int errlen = strlen("SASL Authentication failed on database '': ") + strlen(server_def->db) + strlen(errmsg);
				*error_message = malloc(errlen);
				snprintf(*error_message, errlen, "SASL Authentication failed on database '%s': %s", server_def->db, errmsg);
			} else {
				int errlen = strlen("SASL Authentication failed on database ''") + strlen(server_def->db);
				*error_message = malloc(errlen);
				snprintf(*error_message, errlen, "SASL Authentication failed on database '%s'", server_def->db);
			}

			free(data_buffer);
			return 0;
		}
	}

	if (bson_find_field_as_int32(ptr, "conversationId", &out_conversation_id)) {
		if (out_conversation_id != conversation_id) {
			mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "SASL continue failed: Got wrong conversation_id back! Expected %d but got %d", conversation_id, out_conversation_id);
			free(data_buffer);
			return 0;
		}
		bson_find_field_as_stringl(ptr, "payload", out_payload, out_payload_len, 1);
		bson_find_field_as_bool(ptr, "done", done);
	}
	free(data_buffer);

	return (int)ok;
}
/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: fdm=marker
 * vim: noet sw=4 ts=4
 */