connection.c

关系型数据库 Postgresql 6.5.2

StartupPacket6_2 sp62;
QResultClass *res;
SocketClass *sock;
ConnInfo *ci = &(self->connInfo);
int areq = -1;
int beresp;
char msgbuffer[ERROR_MSG_LENGTH]; 
char salt[2];
static char *func="CC_connect";

	mylog("%s: entering...\n", func);

	if ( do_password)

		sock = self->sock;		/* already connected, just authenticate */

	else {

		qlog("Global Options: Version='%s', fetch=%d, socket=%d, unknown_sizes=%d, max_varchar_size=%d, max_longvarchar_size=%d\n",
			POSTGRESDRIVERVERSION,
			globals.fetch_max, 
			globals.socket_buffersize, 
			globals.unknown_sizes, 
			globals.max_varchar_size, 
			globals.max_longvarchar_size);
		qlog("                disable_optimizer=%d, ksqo=%d, unique_index=%d, use_declarefetch=%d\n",
			globals.disable_optimizer,
			globals.ksqo,
			globals.unique_index,
			globals.use_declarefetch);
		qlog("                text_as_longvarchar=%d, unknowns_as_longvarchar=%d, bools_as_char=%d\n",
			globals.text_as_longvarchar, 
			globals.unknowns_as_longvarchar, 
			globals.bools_as_char);
		qlog("                extra_systable_prefixes='%s', conn_settings='%s'\n",
			globals.extra_systable_prefixes, 
			globals.conn_settings);

		if (self->status != CONN_NOT_CONNECTED) {
			self->errormsg = "Already connected.";
			self->errornumber = CONN_OPENDB_ERROR;
			return 0;
		}

		if ( ci->server[0] == '\0' || ci->port[0] == '\0' || ci->database[0] == '\0') {
			self->errornumber = CONN_INIREAD_ERROR;
			self->errormsg = "Missing server name, port, or database name in call to CC_connect.";
			return 0;
		}

		mylog("CC_connect(): DSN = '%s', server = '%s', port = '%s', database = '%s', username = '%s', password='%s'\n", ci->dsn, ci->server, ci->port, ci->database, ci->username, ci->password);

		/* If the socket was closed for some reason (like a SQLDisconnect, but no SQLFreeConnect
			then create a socket now.
		*/
		if ( ! self->sock) {
			self->sock = SOCK_Constructor();
			if ( ! self->sock) {
				 self->errornumber = CONNECTION_SERVER_NOT_REACHED;
				 self->errormsg = "Could not open a socket to the server";
				 return 0;
			}
		}

		sock = self->sock;

		mylog("connecting to the server socket...\n");

		SOCK_connect_to(sock, (short) atoi(ci->port), ci->server);
		if (SOCK_get_errcode(sock) != 0) {
			mylog("connection to the server socket failed.\n");
			self->errornumber = CONNECTION_SERVER_NOT_REACHED;
			self->errormsg = "Could not connect to the server";
			return 0;
		}
		mylog("connection to the server socket succeeded.\n");

		if ( PROTOCOL_62(ci)) {
			sock->reverse = TRUE;		/* make put_int and get_int work for 6.2 */

			memset(&sp62, 0, sizeof(StartupPacket6_2));
			SOCK_put_int(sock, htonl(4+sizeof(StartupPacket6_2)), 4);
			sp62.authtype = htonl(NO_AUTHENTICATION);
			strncpy(sp62.database, ci->database, PATH_SIZE);
			strncpy(sp62.user, ci->username, NAMEDATALEN);
			SOCK_put_n_char(sock, (char *) &sp62, sizeof(StartupPacket6_2));
			SOCK_flush_output(sock);
		}
		else {
			memset(&sp, 0, sizeof(StartupPacket));

			mylog("sizeof startup packet = %d\n", sizeof(StartupPacket));

			// Send length of Authentication Block
			SOCK_put_int(sock, 4+sizeof(StartupPacket), 4); 

			if ( PROTOCOL_63(ci))
				sp.protoVersion = (ProtocolVersion) htonl(PG_PROTOCOL_63);
			else
				sp.protoVersion = (ProtocolVersion) htonl(PG_PROTOCOL_LATEST);

			strncpy(sp.database, ci->database, SM_DATABASE);
			strncpy(sp.user, ci->username, SM_USER);

			SOCK_put_n_char(sock, (char *) &sp, sizeof(StartupPacket));
			SOCK_flush_output(sock);
		}

		mylog("sent the authentication block.\n");

		if (sock->errornumber != 0) {
			mylog("couldn't send the authentication block properly.\n");
			self->errornumber = CONN_INVALID_AUTHENTICATION;
			self->errormsg = "Sending the authentication packet failed";
			return 0;
		}
		mylog("sent the authentication block successfully.\n");
	}


	mylog("gonna do authentication\n");


	// ***************************************************
	//	Now get the authentication request from backend
	// ***************************************************

	if ( ! PROTOCOL_62(ci))	do {

		if (do_password)
			beresp = 'R';
		else
			beresp = SOCK_get_char(sock);

		switch(beresp) {
		case 'E':
			mylog("auth got 'E'\n");

			SOCK_get_string(sock, msgbuffer, ERROR_MSG_LENGTH);
			self->errornumber = CONN_INVALID_AUTHENTICATION;
			self->errormsg = msgbuffer;
			qlog("ERROR from backend during authentication: '%s'\n", self->errormsg);
			return 0;
		case 'R':

			if (do_password) {
				mylog("in 'R' do_password\n");
				areq = AUTH_REQ_PASSWORD;
				do_password = FALSE;
			}
			else {
				mylog("auth got 'R'\n");

				areq = SOCK_get_int(sock, 4);
				if (areq == AUTH_REQ_CRYPT)
					SOCK_get_n_char(sock, salt, 2);

				mylog("areq = %d\n", areq);
			}
			switch(areq) {
			case AUTH_REQ_OK:
				break;

			case AUTH_REQ_KRB4:
				self->errormsg = "Kerberos 4 authentication not supported";
				self->errornumber = CONN_AUTH_TYPE_UNSUPPORTED;
				return 0;

			case AUTH_REQ_KRB5:
				self->errormsg = "Kerberos 5 authentication not supported";
				self->errornumber = CONN_AUTH_TYPE_UNSUPPORTED;
				return 0;

			case AUTH_REQ_PASSWORD:
				mylog("in AUTH_REQ_PASSWORD\n");

				if (ci->password[0] == '\0') {
					self->errornumber = CONNECTION_NEED_PASSWORD;
					self->errormsg = "A password is required for this connection.";
					return -1;	/* need password */
				}

				mylog("past need password\n");

				SOCK_put_int(sock, 4+strlen(ci->password)+1, 4);
				SOCK_put_n_char(sock, ci->password, strlen(ci->password) + 1);
				SOCK_flush_output(sock);

				mylog("past flush\n");
				break;

			case AUTH_REQ_CRYPT:
				self->errormsg = "Password crypt authentication not supported";
				self->errornumber = CONN_AUTH_TYPE_UNSUPPORTED;
				return 0;

			default:
				self->errormsg = "Unknown authentication type";
				self->errornumber = CONN_AUTH_TYPE_UNSUPPORTED;
				return 0;
			}
			break;
		default:
			self->errormsg = "Unexpected protocol character during authentication";
			self->errornumber = CONN_INVALID_AUTHENTICATION;
			return 0;
		}

	} while (areq != AUTH_REQ_OK);		


	CC_clear_error(self);	/* clear any password error */

	/* send an empty query in order to find out whether the specified */
	/* database really exists on the server machine */
	mylog("sending an empty query...\n");

	res = CC_send_query(self, " ", NULL);
	if ( res == NULL || QR_get_status(res) != PGRES_EMPTY_QUERY) {
		mylog("got no result from the empty query.  (probably database does not exist)\n");
		self->errornumber = CONNECTION_NO_SUCH_DATABASE;
		self->errormsg = "The database does not exist on the server\nor user authentication failed.";
		if (res != NULL)
			QR_Destructor(res);
		return 0;
	}
	if (res)
		QR_Destructor(res);

	mylog("empty query seems to be OK.\n");

	CC_set_translation (self);

	/**********************************************/
	/*******   Send any initial settings  *********/
	/**********************************************/

	/*	Since these functions allocate statements, and since the connection is not
		established yet, it would violate odbc state transition rules.  Therefore,
		these functions call the corresponding local function instead.
	*/
	CC_send_settings(self);
	CC_lookup_lo(self);		/* a hack to get the oid of our large object oid type */

	CC_clear_error(self);	/* clear any initial command errors */
	self->status = CONN_CONNECTED;

	mylog("%s: returning...\n", func);

	return 1;

}

char
CC_add_statement(ConnectionClass *self, StatementClass *stmt)
{
int i;

	mylog("CC_add_statement: self=%u, stmt=%u\n", self, stmt);

	for (i = 0; i < self->num_stmts; i++) {
		if ( ! self->stmts[i]) {
			stmt->hdbc = self;
			self->stmts[i] = stmt;
			return TRUE;
		}
	}

	/* no more room -- allocate more memory */
	self->stmts = (StatementClass **) realloc( self->stmts, sizeof(StatementClass *) * (STMT_INCREMENT + self->num_stmts));
	if ( ! self->stmts)
		return FALSE;

	memset(&self->stmts[self->num_stmts], 0, sizeof(StatementClass *) * STMT_INCREMENT);

	stmt->hdbc = self;
	self->stmts[self->num_stmts] = stmt;

	self->num_stmts += STMT_INCREMENT;

	return TRUE;
}

char 
CC_remove_statement(ConnectionClass *self, StatementClass *stmt)
{
int i;

	for (i = 0; i < self->num_stmts; i++) {
		if (self->stmts[i] == stmt && stmt->status != STMT_EXECUTING) {
			self->stmts[i] = NULL;
			return TRUE;
		}
	}

	return FALSE;
}

/*	Create a more informative error message by concatenating the connection
	error message with its socket error message.
*/
char *
CC_create_errormsg(ConnectionClass *self)
{
SocketClass *sock = self->sock;
int pos;
static char msg[4096];

	mylog("enter CC_create_errormsg\n");

	msg[0] = '\0';

	if (self->errormsg)
		strcpy(msg, self->errormsg);

	mylog("msg = '%s'\n", msg);

	if (sock && sock->errormsg && sock->errormsg[0] != '\0') {
		pos = strlen(msg);
		sprintf(&msg[pos], ";\n%s", sock->errormsg);
	}

	mylog("exit CC_create_errormsg\n");
	return msg;
}


char 
CC_get_error(ConnectionClass *self, int *number, char **message)
{
int rv;

	mylog("enter CC_get_error\n");

	//	Create a very informative errormsg if it hasn't been done yet.
	if ( ! self->errormsg_created) {
		self->errormsg = CC_create_errormsg(self);
		self->errormsg_created = TRUE;
	}

	if (self->errornumber) {
		*number = self->errornumber;
		*message = self->errormsg;
	}
	rv = (self->errornumber != 0);

	self->errornumber = 0;		// clear the error

	mylog("exit CC_get_error\n");

	return rv;
}


/*	The "result_in" is only used by QR_next_tuple() to fetch another group of rows into
	the same existing QResultClass (this occurs when the tuple cache is depleted and
	needs to be re-filled).

	The "cursor" is used by SQLExecute to associate a statement handle as the cursor name
	(i.e., C3326857) for SQL select statements.  This cursor is then used in future 
	'declare cursor C3326857 for ...' and 'fetch 100 in C3326857' statements.
*/
QResultClass *
CC_send_query(ConnectionClass *self, char *query, QueryInfo *qi)
{
QResultClass *result_in, *res = NULL;
char id, swallow;
SocketClass *sock = self->sock;
static char msgbuffer[MAX_MESSAGE_LEN+1];
char cmdbuffer[MAX_MESSAGE_LEN+1];	// QR_set_command() dups this string so dont need static


	mylog("send_query(): conn=%u, query='%s'\n", self, query);
	qlog("conn=%u, query='%s'\n", self, query);

	// Indicate that we are sending a query to the backend
	if(strlen(query) > MAX_MESSAGE_LEN-2) {
		self->errornumber = CONNECTION_MSG_TOO_LONG;
		self->errormsg = "Query string is too long";
		return NULL;
	}

	if ((NULL == query) || (query[0] == '\0'))
		return NULL;

	if (SOCK_get_errcode(sock) != 0) {
		self->errornumber = CONNECTION_COULD_NOT_SEND;
		self->errormsg = "Could not send Query to backend";
		CC_set_no_trans(self);
		return NULL;
	}

	SOCK_put_char(sock, 'Q');
	if (SOCK_get_errcode(sock) != 0) {
		self->errornumber = CONNECTION_COULD_NOT_SEND;
		self->errormsg = "Could not send Query to backend";
		CC_set_no_trans(self);
		return NULL;
	}

	SOCK_put_string(sock, query);
	SOCK_flush_output(sock);

	if (SOCK_get_errcode(sock) != 0) {
		self->errornumber = CONNECTION_COULD_NOT_SEND;
		self->errormsg = "Could not send Query to backend";
		CC_set_no_trans(self);
		return NULL;
	}

	mylog("send_query: done sending query\n");

	while(1) {
		/* what type of message is coming now ? */
		id = SOCK_get_char(sock);

		if ((SOCK_get_errcode(sock) != 0) || (id == EOF)) {
			self->errornumber = CONNECTION_NO_RESPONSE;
			self->errormsg = "No response from the backend";
			if (res)
				QR_Destructor(res);

			mylog("send_query: 'id' - %s\n", self->errormsg);
			CC_set_no_trans(self);
			return NULL;
		}

		mylog("send_query: got id = '%c'\n", id);

		switch (id) {
		case 'A' : /* Asynchronous Messages are ignored */
			(void)SOCK_get_int(sock, 4); /* id of notification */
			SOCK_get_string(sock, msgbuffer, MAX_MESSAGE_LEN);
			/* name of the relation the message comes from */
			break;
		case 'C' : /* portal query command, no tuples returned */
			/* read in the return message from the backend */
			SOCK_get_string(sock, cmdbuffer, MAX_MESSAGE_LEN);
			if (SOCK_get_errcode(sock) != 0) {
				self->errornumber = CONNECTION_NO_RESPONSE;
				self->errormsg = "No response from backend while receiving a portal query command";
				mylog("send_query: 'C' - %s\n", self->errormsg);
				CC_set_no_trans(self);
				return NULL;
			} else {

				char clear = 0;

				mylog("send_query: ok - 'C' - %s\n", cmdbuffer);

				if (res == NULL)	/* allow for "show" style notices */
					res = QR_Constructor();

				mylog("send_query: setting cmdbuffer = '%s'\n", cmdbuffer);

				/*	Only save the first command */