1 files changed, 307 insertions, 0 deletions
diff --git a/source3/smbd/notify_fam.c b/source3/smbd/notify_fam.c
new file mode 100644
index 0000000..2cf1e35
--- /dev/null
+++ b/source3/smbd/notify_fam.c
@@ -0,0 +1,307 @@
+/*
+ * FAM file notification support.
+ *
+ * Copyright (c) James Peach 2005
+ * Copyright (c) Volker Lendecke 2007
+ *
+ * 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 "smbd/smbd.h"
+#include "librpc/gen_ndr/notify.h"
+
+#include <fam.h>
+
+#if !defined(HAVE_FAM_H_FAMCODES_TYPEDEF)
+/* Gamin provides this typedef which means we can't use 'enum FAMCodes' as per
+ * every other FAM implementation. Phooey.
+ */
+typedef enum FAMCodes FAMCodes;
+#endif
+
+/* NOTE: There are multiple versions of FAM floating around the net, each with
+ * slight differences from the original SGI FAM implementation. In this file,
+ * we rely only on the SGI features and do not assume any extensions. For
+ * example, we do not look at FAMErrno, because it is not set by the original
+ * implementation.
+ *
+ * Random FAM links:
+ *	http://oss.sgi.com/projects/fam/
+ *	http://savannah.nongnu.org/projects/fam/
+ *	http://sourceforge.net/projects/bsdfam/
+ */
+
+/* ------------------------------------------------------------------------- */
+
+struct fam_watch_context {
+	struct fam_watch_context *prev, *next;
+	FAMConnection *fam_connection;
+	struct FAMRequest fr;
+	struct sys_notify_context *sys_ctx;
+	void (*callback)(struct sys_notify_context *ctx,
+			 void *private_data,
+			 struct notify_event *ev,
+			 uint32_t filter);
+	void *private_data;
+	uint32_t mask; /* the inotify mask */
+	uint32_t filter; /* the windows completion filter */
+	const char *path;
+};
+
+
+/*
+ * We want one FAM connection per smbd, not one per tcon.
+ */
+static FAMConnection fam_connection;
+static bool fam_connection_initialized = False;
+
+static struct fam_watch_context *fam_notify_list;
+static void fam_handler(struct tevent_context *event_ctx,
+			struct tevent_fd *fd_event,
+			uint16_t flags,
+			void *private_data);
+
+static NTSTATUS fam_open_connection(FAMConnection *fam_conn,
+				    struct tevent_context *event_ctx)
+{
+	int res;
+	char *name;
+
+	ZERO_STRUCTP(fam_conn);
+	FAMCONNECTION_GETFD(fam_conn) = -1;
+
+
+#ifdef HAVE_FAMNOEXISTS
+	/* We should honor outside setting of the GAM_CLIENT_ID. */
+	setenv("GAM_CLIENT_ID","SAMBA",0);
+#endif
+
+	if (asprintf(&name, "smbd (%lu)", (unsigned long)getpid()) == -1) {
+		DEBUG(0, ("No memory\n"));
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	res = FAMOpen2(fam_conn, name);
+
+#ifdef HAVE_FAMNOEXISTS
+	/*
+	 * This reduces the chatter between GAMIN and samba making the pair
+	 * much more reliable.
+	 */
+	FAMNoExists(fam_conn);
+#endif
+
+	SAFE_FREE(name);
+
+	if (res < 0) {
+		DEBUG(10, ("FAM file change notifications not available: %s\n",
+			   FamErrlist[-res]));
+		/*
+		 * No idea how to get NT_STATUS from a FAM result
+		 */
+		FAMCONNECTION_GETFD(fam_conn) = -1;
+		return NT_STATUS_UNEXPECTED_IO_ERROR;
+	}
+
+	if (tevent_add_fd(event_ctx, event_ctx,
+			 FAMCONNECTION_GETFD(fam_conn),
+			 TEVENT_FD_READ, fam_handler,
+			 (void *)fam_conn) == NULL) {
+		DEBUG(0, ("event_add_fd failed\n"));
+		FAMClose(fam_conn);
+		FAMCONNECTION_GETFD(fam_conn) = -1;
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static void fam_reopen(FAMConnection *fam_conn,
+		       struct tevent_context *event_ctx,
+		       struct fam_watch_context *notify_list)
+{
+	struct fam_watch_context *ctx;
+
+	DEBUG(5, ("Re-opening FAM connection\n"));
+
+	FAMClose(fam_conn);
+
+	if (!NT_STATUS_IS_OK(fam_open_connection(fam_conn, event_ctx))) {
+		DEBUG(5, ("Re-opening fam connection failed\n"));
+		return;
+	}
+
+	for (ctx = notify_list; ctx; ctx = ctx->next) {
+		FAMMonitorDirectory(fam_conn, ctx->path, &ctx->fr, NULL);
+	}
+}
+
+static void fam_handler(struct tevent_context *event_ctx,
+			struct tevent_fd *fd_event,
+			uint16_t flags,
+			void *private_data)
+{
+	FAMConnection *fam_conn = (FAMConnection *)private_data;
+	FAMEvent fam_event;
+	struct fam_watch_context *ctx;
+	struct notify_event ne;
+
+	if (FAMPending(fam_conn) == 0) {
+		DEBUG(10, ("fam_handler called but nothing pending\n"));
+		return;
+	}
+
+	if (FAMNextEvent(fam_conn, &fam_event) != 1) {
+		DEBUG(5, ("FAMNextEvent returned an error\n"));
+		TALLOC_FREE(fd_event);
+		fam_reopen(fam_conn, event_ctx, fam_notify_list);
+		return;
+	}
+
+	DEBUG(10, ("Got FAMCode %d for %s\n", fam_event.code,
+		   fam_event.filename));
+
+	switch (fam_event.code) {
+	case FAMChanged:
+		ne.action = NOTIFY_ACTION_MODIFIED;
+		break;
+	case FAMCreated:
+		ne.action = NOTIFY_ACTION_ADDED;
+		break;
+	case FAMDeleted:
+		ne.action = NOTIFY_ACTION_REMOVED;
+		break;
+	default:
+		DEBUG(10, ("Ignoring code FAMCode %d for file %s\n",
+			   (int)fam_event.code, fam_event.filename));
+		return;
+	}
+
+	for (ctx = fam_notify_list; ctx; ctx = ctx->next) {
+		if (memcmp(&fam_event.fr, &ctx->fr, sizeof(FAMRequest)) == 0) {
+			break;
+		}
+	}
+
+	if (ctx == NULL) {
+		DEBUG(5, ("Discarding event for file %s\n",
+			  fam_event.filename));
+		return;
+	}
+
+	if ((ne.path = strrchr_m(fam_event.filename, '\\')) == NULL) {
+		ne.path = fam_event.filename;
+	}
+	ne.dir = ctx->path;
+
+	ctx->callback(ctx->sys_ctx, ctx->private_data, &ne, UINT32_MAX);
+}
+
+static int fam_watch_context_destructor(struct fam_watch_context *ctx)
+{
+	if (FAMCONNECTION_GETFD(ctx->fam_connection) != -1) {
+		FAMCancelMonitor(&fam_connection, &ctx->fr);
+	}
+	DLIST_REMOVE(fam_notify_list, ctx);
+	return 0;
+}
+
+/*
+  add a watch. The watch is removed when the caller calls
+  talloc_free() on *handle
+*/
+int fam_watch(TALLOC_CTX *mem_ctx,
+	      struct sys_notify_context *ctx,
+	      const char *path,
+	      uint32_t *filter,
+	      uint32_t *subdir_filter,
+	      void (*callback)(struct sys_notify_context *ctx,
+			       void *private_data,
+			       struct notify_event *ev,
+			       uint32_t filter),
+	      void *private_data,
+	      void *handle_p)
+{
+	const uint32_t fam_mask = (FILE_NOTIFY_CHANGE_FILE_NAME|
+				   FILE_NOTIFY_CHANGE_DIR_NAME);
+	struct fam_watch_context *watch;
+	void **handle = (void **)handle_p;
+
+	*handle = NULL;
+
+	if ((*filter & fam_mask) == 0) {
+		DEBUG(10, ("filter = %u, ignoring in FAM\n", *filter));
+		return 0;
+	}
+
+	if (!fam_connection_initialized) {
+		if (!NT_STATUS_IS_OK(fam_open_connection(&fam_connection,
+							 ctx->ev))) {
+			/*
+			 * Just let smbd do all the work itself
+			 */
+			return 0;
+		}
+		fam_connection_initialized = True;
+	}
+
+	if (!(watch = talloc(mem_ctx, struct fam_watch_context))) {
+		return ENOMEM;
+	}
+
+	watch->fam_connection = &fam_connection;
+
+	watch->callback = callback;
+	watch->private_data = private_data;
+	watch->sys_ctx = ctx;
+
+	watch->path = talloc_strdup(watch, path);
+	if (watch->path == NULL) {
+		DEBUG(0, ("talloc_asprintf failed\n"));
+		TALLOC_FREE(watch);
+		return ENOMEM;
+	}
+
+	/*
+	 * The FAM module in this early state will only take care of
+	 * FAMCreated and FAMDeleted events, Leave the rest to notifyd
+	 */
+
+	watch->filter = fam_mask;
+	*filter &= ~fam_mask;
+
+	DLIST_ADD(fam_notify_list, watch);
+	talloc_set_destructor(watch, fam_watch_context_destructor);
+
+	/*
+	 * Only directories monitored so far
+	 */
+
+	if (FAMCONNECTION_GETFD(watch->fam_connection) != -1) {
+		FAMMonitorDirectory(watch->fam_connection, watch->path,
+				    &watch->fr, NULL);
+	}
+	else {
+		/*
+		 * If the re-open is successful, this will establish the
+		 * FAMMonitor from the list
+		 */
+		fam_reopen(watch->fam_connection, ctx->ev, fam_notify_list);
+	}
+
+	*handle = watch;
+
+	return 0;
+}