Merge commit

.bzrignore

@@ -1 +1,2 @@
 core/tags
+gateway

core/Makefile

@@ -13,14 +13,21 @@
 # Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 # Copyright SkySQL Ab 2013
+#
+# Revision History
+# Date		Who			Description
+# 13/06/13	Mark Riddoch		Addition of -rdynamic to allow libraries
+# 					to resolve symbols in the main executable
 
 CC=cc
 CFLAGS=-c -I/usr/include -I../include
+LDFLAGS=-rdynamic
 SRCS= atomic.c buffer.c spinlock.c gateway.c gateway_mysql_protocol.c gw_utils.c \
-	utils.c dcb.c
+	utils.c dcb.c load_utils.c
 HDRS= ../include/atomic.h ../include/buffer.h ../include/dcb.h \
 	../include/gateway_mysql.h ../include/gw.h ../include/mysql_protocol.h \
-	../include/session.h ../include/spinlock.h ../include/thread.h
+	../include/session.h ../include/spinlock.h ../include/thread.h \
+	../include/modules.h
 OBJ=$(SRCS:.c=.o)
 LIBS=-lssl
 

core/load_utils.c

@@ -0,0 +1,237 @@
+/*
+ * This file is distributed as part of the SkySQL Gateway.  It 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,
+ * version 2.
+ *
+ * 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, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright SkySQL Ab 2013
+ */
+
+/*
+ * load_utils.c		Utility functions to aid the loading of dynamic modules
+ * 			into the gateway
+ *
+ * Revision History
+ *
+ * Date		Who		Description
+ * 13/06/13	Mark Riddoch	Initial implementation
+ *
+ */
+#include	<sys/param.h>
+#include	<stdio.h>
+#include	<stdlib.h>
+#include	<unistd.h>
+#include	<string.h>
+#include	<dlfcn.h>
+#include	<modules.h>
+
+static	MODULES	*registered = NULL;
+
+static MODULES *find_module(const char *module);
+static void register_module(const char *module, const char *type, void *dlhandle, char *version, void *modobj);
+static void unregister_module(const char *module);
+
+/*
+ * Load the dynamic library related to a gateway module. The routine
+ * will look for library files in the current directory, 
+ * $GATEWAY_HOME/modules and /usr/local/skysql/gateway/modules.
+ *
+ * @param module	Name of the module to load
+ * @param type		Type of module, used purely for registration
+ * @param entry		Routine to call to extract entry points
+ * @return		The module specific entry point structure or NULL
+ */
+void *
+load_module(const char *module, const char *type, const char *entry)
+{
+char	*home, *version;
+char	fname[MAXPATHLEN];
+void	*dlhandle, *sym;
+char	*(*ver)();
+void	*(*ep)(), *modobj;
+MODULES	*mod;
+
+	if ((mod = find_module(module)) == NULL)
+	{
+		/*
+		 * The module is not already loaded
+		 *
+		 * Search of the shared object.
+		 */
+		sprintf(fname, "lib%s.so", module);
+		if (access(fname, F_OK) == -1)
+		{
+			if ((home = getenv("GATEWAY_HOME")) == NULL)
+				home = "/usr/local/skysql/gateway";
+			sprintf(fname, "%s/modules/lib%s.so", home, module);
+			if (access(fname, F_OK) == -1)
+			{
+				fprintf(stderr, "Unable to find library for module: %s\n", module);
+				return NULL;
+			}
+		}
+		if ((dlhandle = dlopen(fname, RTLD_NOW|RTLD_LOCAL)) == NULL)
+		{
+			fprintf(stderr, "Unable to load library for module: %s, %s\n", module, dlerror());
+			return NULL;
+		}
+
+		if ((sym = dlsym(dlhandle, "version")) == NULL)
+		{
+			fprintf(stderr, "Version interface not supported by module: %s, %s\n", module, dlerror());
+			dlclose(dlhandle);
+			return NULL;
+		}
+		ver = sym;
+		version = ver();
+
+		if ((sym = dlsym(dlhandle, entry)) == NULL)
+		{
+			fprintf(stderr, "Expected entry point interface missing from module: %s, %s\n", module, dlerror());
+			dlclose(dlhandle);
+			return NULL;
+		}
+		ep = sym;
+		modobj = ep();
+
+		fprintf(stderr, "Loaded module %s: %s\n", module, version);
+		register_module(module, type, dlhandle, version, modobj);
+	}
+	else
+	{
+		/*
+		 * The module is already loaded, get the entry points again and
+		 * return a reference to the already loaded module.
+		 */
+		modobj = mod->modobj;
+	}
+
+	return modobj;
+}
+
+/*
+ * Unload a module.
+ *
+ * No errors are returned since it is not clear that much can be done
+ * to fix issues relating to unloading modules.
+ *
+ * @param module	The name of the module
+ */
+void
+unload_module(const char *module)
+{
+MODULES	*mod = find_module(module);
+void	*handle;
+
+	if (!mod)
+		return;
+	handle = mod->handle;
+	unregister_module(module);
+	dlclose(handle);
+}
+
+/*
+ * Find a module that has been previously loaded and return the handle for that
+ * library
+ *
+ * @param module	The name of the module
+ * @return		The module handle or NULL if it was not found
+ */
+static MODULES *
+find_module(const char *module)
+{
+MODULES	*ptr = registered;
+
+	while (registered)
+		if (strcmp(registered->module, module))
+			return registered;
+		else
+			registered = registered->next;
+	return NULL;
+}
+
+/*
+ * Register a newly loaded module. The registration allows for single copies
+ * to be loaded and cached entry point information to be return.
+ *
+ * @param module	The name of the module loaded
+ * @param type		The type of the module loaded
+ * @param dlhandle	The handle returned by dlopen
+ * @param version	The version string returned by the module
+ * @param modobj	The module object
+ */
+static void
+register_module(const char *module, const char *type, void *dlhandle, char *version, void *modobj)
+{
+MODULES	*mod;
+
+	if ((mod = malloc(sizeof(MODULES))) == NULL)
+		return;
+	mod->module = strdup(module);
+	mod->type = strdup(type);
+	mod->handle = dlhandle;
+	mod->version = strdup(version);
+	mod->modobj = modobj;
+	mod->next = registered;
+	registered = mod;
+}
+
+/*
+ * Unregister a module
+ *
+ * @param module	The name of the module to remove
+ */
+static void
+unregister_module(const char *module)
+{
+MODULES	*mod = find_module(module);
+MODULES	*ptr;
+
+	if (!mod)
+		return;		// Module not found
+	if (registered == mod)
+		registered = mod->next;
+	else
+	{
+		ptr = registered;
+		while (ptr && ptr->next != mod)
+			ptr = ptr->next;
+	}
+
+	/*
+	 * The module is now not in the linked list and all
+	 * memory related to it can be freed
+	 */
+	free(mod->module);
+	free(mod->type);
+	free(mod->version);
+	free(mod);
+}
+
+/*
+ * Print Modules
+ *
+ * Diagnostic routine to display all the loaded modules
+ */
+void
+printModules()
+{
+MODULES	*ptr = registered;
+
+	printf("%-15s | %-10s | Version\n", "Module Name", "Module Type");
+	printf("-----------------------------------------------------\n");
+	while (ptr)
+	{
+		printf("%-15s | %-10s | %s\n", ptr->module, ptr->type, ptr->version);
+		ptr = ptr->next;
+	}
+}

include/gw.h

@@ -55,7 +55,7 @@ int handle_event_errors(DCB *dcb, int event);
 int handle_event_errors_backend(DCB *dcb, int event);
 void MySQLListener(int epfd, char *config_bind);
 int MySQLAccept(DCB *listener, int efd);
-int gw_mysql_do_authentication(DCB *dcb);
+int gw_mysql_do_authentication(DCB *dcb, GWBUF *);
 void gw_mysql_close(MySQLProtocol **ptr);
 char *gw_strend(register const char *s);
 int do_read_dcb(DCB *dcb);

include/modules.h

@@ -0,0 +1,44 @@
+#ifndef _MODULES_H
+#define _MODULES_H
+/*
+ * This file is distributed as part of the SkySQL Gateway.  It 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,
+ * version 2.
+ *
+ * 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, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright SkySQL Ab 2013
+ */
+
+/*
+ * The module interface used within the gateway
+ *
+ * Revision History
+ *
+ * Date		Who		Description
+ * 13/06/13	Mark Riddoch	Initial implementation
+ *
+ */
+
+typedef struct modules {
+	char	*module;	/* The name of the module */
+	char	*type;		/* The module type */
+	char	*version;	/* Module version */
+	void	*handle;	/* The handle returned by dlopen */
+	void	*modobj;	/* The module "object" this is the set of entry points */
+	struct	modules
+		*next;		/* Next module in the linked list */
+} MODULES;
+
+extern	void 	*load_module(const char *module, const char *type, const char *entry);
+extern	void	unload_module(const char *module);
+extern	void	printModules();
+#endif