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From: David Howells <dhowells@redhat.com>
To: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk
Cc: dhowells@redhat.com, casey@schaufler-ca.com, sds@tycho.nsa.gov,
	nicolas.dichtel@6wind.com, raven@themaw.net,
	christian@brauner.io, andres@anarazel.de, jlayton@redhat.com,
	dray@redhat.com, kzak@redhat.com, keyrings@vger.kernel.org,
	linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 01/17] uapi: General notification queue definitions [ver #5]
Date: Wed, 18 Mar 2020 15:03:17 +0000	[thread overview]
Message-ID: <158454379781.2863966.14636232398055723657.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <158454378820.2863966.10496767254293183123.stgit@warthog.procyon.org.uk>

Add UAPI definitions for the general notification queue, including the
following pieces:

 (*) struct watch_notification.

     This is the metadata header for notification messages.  It includes a
     type and subtype that indicate the source of the message
     (eg. WATCH_TYPE_MOUNT_NOTIFY) and the kind of the message
     (eg. NOTIFY_MOUNT_NEW_MOUNT).

     The header also contains an information field that conveys the
     following information:

	- WATCH_INFO_LENGTH.  The size of the entry (entries are variable
          length).

	- WATCH_INFO_ID.  The watch ID specified when the watchpoint was
          set.

	- WATCH_INFO_TYPE_INFO.  (Sub)type-specific information.

	- WATCH_INFO_FLAG_*.  Flag bits overlain on the type-specific
          information.  For use by the type.

     All the information in the header can be used in filtering messages at
     the point of writing into the buffer.

 (*) struct watch_notification_removal

     This is an extended watch-removal notification record that includes an
     'id' field that can indicate the identifier of the object being
     removed if available (for instance, a keyring serial number).

Signed-off-by: David Howells <dhowells@redhat.com>
---

 include/uapi/linux/watch_queue.h |   55 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 include/uapi/linux/watch_queue.h

diff --git a/include/uapi/linux/watch_queue.h b/include/uapi/linux/watch_queue.h
new file mode 100644
index 000000000000..5f3d21e8a34b
--- /dev/null
+++ b/include/uapi/linux/watch_queue.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_LINUX_WATCH_QUEUE_H
+#define _UAPI_LINUX_WATCH_QUEUE_H
+
+#include <linux/types.h>
+
+enum watch_notification_type {
+	WATCH_TYPE_META		= 0,	/* Special record */
+	WATCH_TYPE__NR		= 1
+};
+
+enum watch_meta_notification_subtype {
+	WATCH_META_REMOVAL_NOTIFICATION	= 0,	/* Watched object was removed */
+	WATCH_META_LOSS_NOTIFICATION	= 1,	/* Data loss occurred */
+};
+
+/*
+ * Notification record header.  This is aligned to 64-bits so that subclasses
+ * can contain __u64 fields.
+ */
+struct watch_notification {
+	__u32			type:24;	/* enum watch_notification_type */
+	__u32			subtype:8;	/* Type-specific subtype (filterable) */
+	__u32			info;
+#define WATCH_INFO_LENGTH	0x0000007f	/* Length of record */
+#define WATCH_INFO_LENGTH__SHIFT 0
+#define WATCH_INFO_ID		0x0000ff00	/* ID of watchpoint */
+#define WATCH_INFO_ID__SHIFT	8
+#define WATCH_INFO_TYPE_INFO	0xffff0000	/* Type-specific info */
+#define WATCH_INFO_TYPE_INFO__SHIFT 16
+#define WATCH_INFO_FLAG_0	0x00010000	/* Type-specific info, flag bit 0 */
+#define WATCH_INFO_FLAG_1	0x00020000	/* ... */
+#define WATCH_INFO_FLAG_2	0x00040000
+#define WATCH_INFO_FLAG_3	0x00080000
+#define WATCH_INFO_FLAG_4	0x00100000
+#define WATCH_INFO_FLAG_5	0x00200000
+#define WATCH_INFO_FLAG_6	0x00400000
+#define WATCH_INFO_FLAG_7	0x00800000
+};
+
+
+/*
+ * Extended watch removal notification.  This is used optionally if the type
+ * wants to indicate an identifier for the object being watched, if there is
+ * such.  This can be distinguished by the length.
+ *
+ * type -> WATCH_TYPE_META
+ * subtype -> WATCH_META_REMOVAL_NOTIFICATION
+ */
+struct watch_notification_removal {
+	struct watch_notification watch;
+	__u64	id;		/* Type-dependent identifier */
+};
+
+#endif /* _UAPI_LINUX_WATCH_QUEUE_H */



  reply	other threads:[~2020-03-18 15:03 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-18 15:03 [PATCH 00/17] pipe: Keyrings, mount and superblock notifications " David Howells
2020-03-18 15:03 ` David Howells [this message]
2020-03-18 15:03 ` [PATCH 02/17] security: Add hooks to rule on setting a watch " David Howells
2020-03-18 18:56   ` James Morris
2020-03-18 15:03 ` [PATCH 03/17] security: Add a hook for the point of notification insertion " David Howells
2020-03-18 18:57   ` James Morris
2020-03-18 15:03 ` [PATCH 04/17] pipe: Add O_NOTIFICATION_PIPE " David Howells
2020-03-18 15:03 ` [PATCH 05/17] pipe: Add general notification queue support " David Howells
2020-03-18 15:04 ` [PATCH 06/17] watch_queue: Add a key/keyring notification facility " David Howells
2020-03-18 19:04   ` James Morris
2020-03-18 15:04 ` [PATCH 07/17] Add sample notification program " David Howells
2020-03-18 15:04 ` [PATCH 08/17] pipe: Allow buffers to be marked read-whole-or-error for notifications " David Howells
2020-03-18 15:04 ` [PATCH 09/17] pipe: Add notification lossage handling " David Howells
2020-03-18 15:04 ` [PATCH 10/17] selinux: Implement the watch_key security hook " David Howells
2020-03-18 19:06   ` James Morris
2020-03-18 15:04 ` [PATCH 11/17] smack: Implement the watch_key and post_notification hooks " David Howells
2020-03-18 15:05 ` [PATCH 12/17] watch_queue: Add security hooks to rule on setting mount and sb watches " David Howells
2020-03-18 19:07   ` James Morris
2020-03-18 15:05 ` [PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications " David Howells
2020-04-02 15:19   ` Miklos Szeredi
2020-06-14  3:07     ` Ian Kent
2020-06-15  8:44       ` Miklos Szeredi
2020-07-23 10:48   ` David Howells
2020-08-03  9:29     ` Miklos Szeredi
2020-08-04 11:38       ` Ian Kent
2020-08-04 13:19         ` Miklos Szeredi
2020-08-05  1:53           ` Ian Kent
2020-08-05  7:43             ` Miklos Szeredi
2020-08-05 11:36               ` Ian Kent
2020-08-05 11:56                 ` Miklos Szeredi
2020-07-24 10:19   ` David Howells
2020-07-24 10:44     ` Ian Kent
2020-07-24 11:36     ` David Howells
2020-08-03 10:02       ` Miklos Szeredi
2020-08-03 10:08       ` David Howells
2020-08-03 10:18       ` David Howells
2020-08-03 11:17         ` Miklos Szeredi
2020-08-03 11:49         ` David Howells
2020-08-03 12:01           ` Ian Kent
2020-08-03 12:31           ` David Howells
2020-08-03 14:30             ` Ian Kent
2020-03-18 15:05 ` [PATCH 14/17] watch_queue: sample: Display mount tree " David Howells
2020-03-18 15:05 ` [PATCH 15/17] watch_queue: Introduce a non-repeating system-unique superblock ID " David Howells
2020-03-18 15:05 ` [PATCH 16/17] watch_queue: Add superblock notifications " David Howells
2020-03-18 15:05 ` [PATCH 17/17] watch_queue: sample: Display " David Howells

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