LXR linux/include/uapi/linux/watch

   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2#ifndef _UAPI_LINUX_WATCH_QUEUE_H
   3#define _UAPI_LINUX_WATCH_QUEUE_H
   4
   5#include <linux/types.h>
   6#include <linux/fcntl.h>
   7#include <linux/ioctl.h>
   8
   9#define O_NOTIFICATION_PIPE     O_EXCL  /* Parameter to pipe2() selecting notification pipe */
  10
  11#define IOC_WATCH_QUEUE_SET_SIZE        _IO('W', 0x60)  /* Set the size in pages */
  12#define IOC_WATCH_QUEUE_SET_FILTER      _IO('W', 0x61)  /* Set the filter */
  13
  14enum watch_notification_type {
  15        WATCH_TYPE_META         = 0,    /* Special record */
  16        WATCH_TYPE_KEY_NOTIFY   = 1,    /* Key change event notification */
  17        WATCH_TYPE__NR          = 2
  18};
  19
  20enum watch_meta_notification_subtype {
  21        WATCH_META_REMOVAL_NOTIFICATION = 0,    /* Watched object was removed */
  22        WATCH_META_LOSS_NOTIFICATION    = 1,    /* Data loss occurred */
  23};
  24
  25/*
  26 * Notification record header.  This is aligned to 64-bits so that subclasses
  27 * can contain __u64 fields.
  28 */
  29struct watch_notification {
  30        __u32                   type:24;        /* enum watch_notification_type */
  31        __u32                   subtype:8;      /* Type-specific subtype (filterable) */
  32        __u32                   info;
  33#define WATCH_INFO_LENGTH       0x0000007f      /* Length of record */
  34#define WATCH_INFO_LENGTH__SHIFT 0
  35#define WATCH_INFO_ID           0x0000ff00      /* ID of watchpoint */
  36#define WATCH_INFO_ID__SHIFT    8
  37#define WATCH_INFO_TYPE_INFO    0xffff0000      /* Type-specific info */
  38#define WATCH_INFO_TYPE_INFO__SHIFT 16
  39#define WATCH_INFO_FLAG_0       0x00010000      /* Type-specific info, flag bit 0 */
  40#define WATCH_INFO_FLAG_1       0x00020000      /* ... */
  41#define WATCH_INFO_FLAG_2       0x00040000
  42#define WATCH_INFO_FLAG_3       0x00080000
  43#define WATCH_INFO_FLAG_4       0x00100000
  44#define WATCH_INFO_FLAG_5       0x00200000
  45#define WATCH_INFO_FLAG_6       0x00400000
  46#define WATCH_INFO_FLAG_7       0x00800000
  47};
  48
  49/*
  50 * Notification filtering rules (IOC_WATCH_QUEUE_SET_FILTER).
  51 */
  52struct watch_notification_type_filter {
  53        __u32   type;                   /* Type to apply filter to */
  54        __u32   info_filter;            /* Filter on watch_notification::info */
  55        __u32   info_mask;              /* Mask of relevant bits in info_filter */
  56        __u32   subtype_filter[8];      /* Bitmask of subtypes to filter on */
  57};
  58
  59struct watch_notification_filter {
  60        __u32   nr_filters;             /* Number of filters */
  61        __u32   __reserved;             /* Must be 0 */
  62        struct watch_notification_type_filter filters[];
  63};
  64
  65
  66/*
  67 * Extended watch removal notification.  This is used optionally if the type
  68 * wants to indicate an identifier for the object being watched, if there is
  69 * such.  This can be distinguished by the length.
  70 *
  71 * type -> WATCH_TYPE_META
  72 * subtype -> WATCH_META_REMOVAL_NOTIFICATION
  73 */
  74struct watch_notification_removal {
  75        struct watch_notification watch;
  76        __u64   id;             /* Type-dependent identifier */
  77};
  78
  79/*
  80 * Type of key/keyring change notification.
  81 */
  82enum key_notification_subtype {
  83        NOTIFY_KEY_INSTANTIATED = 0, /* Key was instantiated (aux is error code) */
  84        NOTIFY_KEY_UPDATED      = 1, /* Key was updated */
  85        NOTIFY_KEY_LINKED       = 2, /* Key (aux) was added to watched keyring */
  86        NOTIFY_KEY_UNLINKED     = 3, /* Key (aux) was removed from watched keyring */
  87        NOTIFY_KEY_CLEARED      = 4, /* Keyring was cleared */
  88        NOTIFY_KEY_REVOKED      = 5, /* Key was revoked */
  89        NOTIFY_KEY_INVALIDATED  = 6, /* Key was invalidated */
  90        NOTIFY_KEY_SETATTR      = 7, /* Key's attributes got changed */
  91};
  92
  93/*
  94 * Key/keyring notification record.
  95 * - watch.type = WATCH_TYPE_KEY_NOTIFY
  96 * - watch.subtype = enum key_notification_type
  97 */
  98struct key_notification {
  99        struct watch_notification watch;
 100        __u32   key_id;         /* The key/keyring affected */
 101        __u32   aux;            /* Per-type auxiliary data */
 102};
 103
 104#endif /* _UAPI_LINUX_WATCH_QUEUE_H */
 105