1 files changed, 313 insertions, 0 deletions
diff --git a/source4/ntvfs/sysdep/inotify.c b/source4/ntvfs/sysdep/inotify.c
new file mode 100644
index 0000000000..31c408d112
--- /dev/null
+++ b/source4/ntvfs/sysdep/inotify.c
@@ -0,0 +1,313 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/*
+  notify implementation using inotify
+*/
+
+#include "includes.h"
+#include "system/filesys.h"
+#include "ntvfs/sysdep/sys_notify.h"
+#include "lib/events/events.h"
+#include "smb.h"
+#include "dlinklist.h"
+
+#include <linux/inotify.h>
+#include <asm/unistd.h>
+
+#ifndef HAVE_INOTIFY_INIT
+/*
+  glibc doesn't define these functions yet (as of March 2006)
+*/
+static int inotify_init(void)
+{
+	return syscall(__NR_inotify_init);
+}
+
+static int inotify_add_watch(int fd, const char *path, __u32 mask)
+{
+	return syscall(__NR_inotify_add_watch, fd, path, mask);
+}
+
+static int inotify_rm_watch(int fd, int wd)
+{
+	return syscall(__NR_inotify_rm_watch, fd, wd);
+}
+#endif
+
+
+/* older glibc headers don't have these defines either */
+#ifndef IN_ONLYDIR
+#define IN_ONLYDIR 0x01000000
+#endif
+#ifndef IN_MASK_ADD
+#define IN_MASK_ADD 0x20000000
+#endif
+
+struct inotify_private {
+	struct sys_notify_context *ctx;
+	int fd;
+	struct watch_context *watches;
+};
+
+struct watch_context {
+	struct watch_context *next, *prev;
+	struct inotify_private *in;
+	int wd;
+	sys_notify_callback_t callback;
+	void *private;
+	uint32_t mask;
+};
+
+
+/*
+  destroy the inotify private context
+*/
+static int inotify_destructor(void *ptr)
+{
+	struct inotify_private *in = talloc_get_type(ptr, struct inotify_private);
+	close(in->fd);
+	return 0;
+}
+
+
+/*
+  dispatch one inotify event
+*/
+static void inotify_dispatch(struct inotify_private *in, struct inotify_event *e)
+{
+	struct watch_context *w;
+	struct notify_event ne;
+
+	/* ignore extraneous events, such as unmount and IN_IGNORED events */
+	if ((e->mask & (IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
+		return;
+	}
+
+	/* map the inotify mask to a action */
+	if (e->mask & IN_CREATE) {
+		ne.action = NOTIFY_ACTION_ADDED;
+	} else if (e->mask & IN_DELETE) {
+		ne.action = NOTIFY_ACTION_REMOVED;
+	} else {
+		ne.action = NOTIFY_ACTION_MODIFIED;
+	}
+	ne.path = e->name;
+
+	/* find any watches that have this watch descriptor */
+	for (w=in->watches;w;w=w->next) {
+		/* checking the mask copes with multiple watches */
+		if (w->wd == e->wd && (e->mask & w->mask) != 0) {
+			w->callback(in->ctx, w->private, &ne);
+		}
+	}
+}
+
+/*
+  called when the kernel has some events for us
+*/
+static void inotify_handler(struct event_context *ev, struct fd_event *fde,
+			    uint16_t flags, void *private)
+{
+	struct inotify_private *in = talloc_get_type(private, struct inotify_private);
+	int bufsize = 0;
+	struct inotify_event *e0, *e;
+
+	/*
+	  we must use FIONREAD as we cannot predict the length of the
+	  filenames, and thus can't know how much to allocate
+	  otherwise
+	*/
+	if (ioctl(in->fd, FIONREAD, &bufsize) != 0 || 
+	    bufsize == 0) {
+		DEBUG(0,("No data on inotify fd?!\n"));
+		return;
+	}
+
+	e0 = e = talloc_size(in, bufsize);
+	if (e == NULL) return;
+
+	if (read(in->fd, e0, bufsize) != bufsize) {
+		DEBUG(0,("Failed to read all inotify data\n"));
+		talloc_free(e0);
+		return;
+	}
+
+	/* we can get more than one event in the buffer */
+	while (bufsize >= sizeof(*e)) {
+		inotify_dispatch(in, e);
+		bufsize -= e->len + sizeof(*e);
+		e = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
+	}
+
+	talloc_free(e0);
+}
+
+/*
+  setup the inotify handle - called the first time a watch is added on
+  this context
+*/
+static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
+{
+	struct inotify_private *in;
+
+	in = talloc(ctx, struct inotify_private);
+	NT_STATUS_HAVE_NO_MEMORY(in);
+	in->fd = inotify_init();
+	if (in->fd == -1) {
+		DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
+		talloc_free(in);
+		return map_nt_error_from_unix(errno);
+	}
+	in->ctx = ctx;
+	in->watches = NULL;
+
+	ctx->private = in;
+	talloc_set_destructor(in, inotify_destructor);
+
+	/* add a event waiting for the inotify fd to be readable */
+	event_add_fd(ctx->ev, in, in->fd, EVENT_FD_READ, inotify_handler, in);
+	
+	return NT_STATUS_OK;
+}
+
+
+/*
+  map from a change notify mask to a inotify mask. Approximate only :(
+*/
+static const struct {
+	uint32_t notify_mask;
+	uint32_t inotify_mask;
+} inotify_mapping[] = {
+	{FILE_NOTIFY_CHANGE_FILE_NAME,  IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
+	{FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB},
+	{FILE_NOTIFY_CHANGE_SIZE,       IN_MODIFY},
+	{FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
+	{FILE_NOTIFY_CHANGE_EA,         IN_ATTRIB},
+	{FILE_NOTIFY_CHANGE_SECURITY,   IN_ATTRIB}
+};
+
+static uint32_t inotify_map(uint32_t mask)
+{
+	int i;
+	uint32_t out=0;
+	for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
+		if (inotify_mapping[i].notify_mask & mask) {
+			out |= inotify_mapping[i].inotify_mask;
+		}
+	}
+	return out;
+}
+
+/*
+  destroy a watch
+*/
+static int watch_destructor(void *ptr)
+{
+	struct watch_context *w = talloc_get_type(ptr, struct watch_context);
+	struct inotify_private *in = w->in;
+	int wd = w->wd;
+	DLIST_REMOVE(w->in->watches, w);
+
+	/* only rm the watch if its the last one with this wd */
+	for (w=in->watches;w;w=w->next) {
+		if (w->wd == wd) break;
+	}
+	if (w == NULL) {
+		inotify_rm_watch(in->fd, wd);
+	}
+	return 0;
+}
+
+
+/*
+  add a watch. The watch is removed when the caller calls
+  talloc_free() on handle
+*/
+static NTSTATUS inotify_watch(struct sys_notify_context *ctx, const char *dirpath,
+			      uint32_t filter, sys_notify_callback_t callback,
+			      void *private, void **handle)
+{
+	struct inotify_private *in;
+	int wd;
+	uint32_t mask;
+	struct watch_context *w;
+
+	/* maybe setup the inotify fd */
+	if (ctx->private == NULL) {
+		NTSTATUS status;
+		status = inotify_setup(ctx);
+		NT_STATUS_NOT_OK_RETURN(status);
+	}
+
+	in = talloc_get_type(ctx->private, struct inotify_private);
+
+	mask = inotify_map(filter);
+	if (mask == 0) {
+		/* this filter can't be handled by inotify */
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	/* using IN_MASK_ADD allows us to cope with inotify() returning the same
+	   watch descriptor for muliple watches on the same path */
+	mask |= (IN_MASK_ADD | IN_ONLYDIR);
+
+	/* get a new watch descriptor for this path */
+	wd = inotify_add_watch(in->fd, dirpath, mask);
+	if (wd == -1) {
+		return map_nt_error_from_unix(errno);
+	}
+
+	w = talloc(in, struct watch_context);
+	if (w == NULL) {
+		inotify_rm_watch(in->fd, wd);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	w->in = in;
+	w->wd = wd;
+	w->callback = callback;
+	w->private = private;
+	w->mask = mask;
+
+	(*handle) = w;
+
+	DLIST_ADD(in->watches, w);
+
+	/* the caller frees the handle to stop watching */
+	talloc_set_destructor(w, watch_destructor);
+	
+	return NT_STATUS_OK;
+}
+
+
+static struct sys_notify_backend inotify = {
+	.name = "inotify",
+	.notify_watch = inotify_watch
+};
+
+/*
+  initialialise the inotify module
+ */
+NTSTATUS ntvfs_inotify_init(void)
+{
+	/* register ourselves as a system inotify module */
+	return sys_notify_register(&inotify);
+}