xref: /linux/include/uapi/linux/fanotify.h (revision 8c2c2549)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _UAPI_LINUX_FANOTIFY_H
3 #define _UAPI_LINUX_FANOTIFY_H
4 
5 #include <linux/types.h>
6 
7 /* the following events that user-space can register for */
8 #define FAN_ACCESS		0x00000001	/* File was accessed */
9 #define FAN_MODIFY		0x00000002	/* File was modified */
10 #define FAN_ATTRIB		0x00000004	/* Metadata changed */
11 #define FAN_CLOSE_WRITE		0x00000008	/* Writable file closed */
12 #define FAN_CLOSE_NOWRITE	0x00000010	/* Unwritable file closed */
13 #define FAN_OPEN		0x00000020	/* File was opened */
14 #define FAN_MOVED_FROM		0x00000040	/* File was moved from X */
15 #define FAN_MOVED_TO		0x00000080	/* File was moved to Y */
16 #define FAN_CREATE		0x00000100	/* Subfile was created */
17 #define FAN_DELETE		0x00000200	/* Subfile was deleted */
18 #define FAN_DELETE_SELF		0x00000400	/* Self was deleted */
19 #define FAN_MOVE_SELF		0x00000800	/* Self was moved */
20 #define FAN_OPEN_EXEC		0x00001000	/* File was opened for exec */
21 
22 #define FAN_Q_OVERFLOW		0x00004000	/* Event queued overflowed */
23 #define FAN_FS_ERROR		0x00008000	/* Filesystem error */
24 
25 #define FAN_OPEN_PERM		0x00010000	/* File open in perm check */
26 #define FAN_ACCESS_PERM		0x00020000	/* File accessed in perm check */
27 #define FAN_OPEN_EXEC_PERM	0x00040000	/* File open/exec in perm check */
28 
29 #define FAN_EVENT_ON_CHILD	0x08000000	/* Interested in child events */
30 
31 #define FAN_RENAME		0x10000000	/* File was renamed */
32 
33 #define FAN_ONDIR		0x40000000	/* Event occurred against dir */
34 
35 /* helper events */
36 #define FAN_CLOSE		(FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */
37 #define FAN_MOVE		(FAN_MOVED_FROM | FAN_MOVED_TO) /* moves */
38 
39 /* flags used for fanotify_init() */
40 #define FAN_CLOEXEC		0x00000001
41 #define FAN_NONBLOCK		0x00000002
42 
43 /* These are NOT bitwise flags.  Both bits are used together.  */
44 #define FAN_CLASS_NOTIF		0x00000000
45 #define FAN_CLASS_CONTENT	0x00000004
46 #define FAN_CLASS_PRE_CONTENT	0x00000008
47 
48 /* Deprecated - do not use this in programs and do not add new flags here! */
49 #define FAN_ALL_CLASS_BITS	(FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
50 				 FAN_CLASS_PRE_CONTENT)
51 
52 #define FAN_UNLIMITED_QUEUE	0x00000010
53 #define FAN_UNLIMITED_MARKS	0x00000020
54 #define FAN_ENABLE_AUDIT	0x00000040
55 
56 /* Flags to determine fanotify event format */
57 #define FAN_REPORT_PIDFD	0x00000080	/* Report pidfd for event->pid */
58 #define FAN_REPORT_TID		0x00000100	/* event->pid is thread id */
59 #define FAN_REPORT_FID		0x00000200	/* Report unique file id */
60 #define FAN_REPORT_DIR_FID	0x00000400	/* Report unique directory id */
61 #define FAN_REPORT_NAME		0x00000800	/* Report events with name */
62 #define FAN_REPORT_TARGET_FID	0x00001000	/* Report dirent target id  */
63 
64 /* Convenience macro - FAN_REPORT_NAME requires FAN_REPORT_DIR_FID */
65 #define FAN_REPORT_DFID_NAME	(FAN_REPORT_DIR_FID | FAN_REPORT_NAME)
66 /* Convenience macro - FAN_REPORT_TARGET_FID requires all other FID flags */
67 #define FAN_REPORT_DFID_NAME_TARGET (FAN_REPORT_DFID_NAME | \
68 				     FAN_REPORT_FID | FAN_REPORT_TARGET_FID)
69 
70 /* Deprecated - do not use this in programs and do not add new flags here! */
71 #define FAN_ALL_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK | \
72 				 FAN_ALL_CLASS_BITS | FAN_UNLIMITED_QUEUE |\
73 				 FAN_UNLIMITED_MARKS)
74 
75 /* flags used for fanotify_modify_mark() */
76 #define FAN_MARK_ADD		0x00000001
77 #define FAN_MARK_REMOVE		0x00000002
78 #define FAN_MARK_DONT_FOLLOW	0x00000004
79 #define FAN_MARK_ONLYDIR	0x00000008
80 /* FAN_MARK_MOUNT is		0x00000010 */
81 #define FAN_MARK_IGNORED_MASK	0x00000020
82 #define FAN_MARK_IGNORED_SURV_MODIFY	0x00000040
83 #define FAN_MARK_FLUSH		0x00000080
84 /* FAN_MARK_FILESYSTEM is	0x00000100 */
85 #define FAN_MARK_EVICTABLE	0x00000200
86 /* This bit is mutually exclusive with FAN_MARK_IGNORED_MASK bit */
87 #define FAN_MARK_IGNORE		0x00000400
88 
89 /* These are NOT bitwise flags.  Both bits can be used togther.  */
90 #define FAN_MARK_INODE		0x00000000
91 #define FAN_MARK_MOUNT		0x00000010
92 #define FAN_MARK_FILESYSTEM	0x00000100
93 
94 /*
95  * Convenience macro - FAN_MARK_IGNORE requires FAN_MARK_IGNORED_SURV_MODIFY
96  * for non-inode mark types.
97  */
98 #define FAN_MARK_IGNORE_SURV	(FAN_MARK_IGNORE | FAN_MARK_IGNORED_SURV_MODIFY)
99 
100 /* Deprecated - do not use this in programs and do not add new flags here! */
101 #define FAN_ALL_MARK_FLAGS	(FAN_MARK_ADD |\
102 				 FAN_MARK_REMOVE |\
103 				 FAN_MARK_DONT_FOLLOW |\
104 				 FAN_MARK_ONLYDIR |\
105 				 FAN_MARK_MOUNT |\
106 				 FAN_MARK_IGNORED_MASK |\
107 				 FAN_MARK_IGNORED_SURV_MODIFY |\
108 				 FAN_MARK_FLUSH)
109 
110 /* Deprecated - do not use this in programs and do not add new flags here! */
111 #define FAN_ALL_EVENTS (FAN_ACCESS |\
112 			FAN_MODIFY |\
113 			FAN_CLOSE |\
114 			FAN_OPEN)
115 
116 /*
117  * All events which require a permission response from userspace
118  */
119 /* Deprecated - do not use this in programs and do not add new flags here! */
120 #define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM |\
121 			     FAN_ACCESS_PERM)
122 
123 /* Deprecated - do not use this in programs and do not add new flags here! */
124 #define FAN_ALL_OUTGOING_EVENTS	(FAN_ALL_EVENTS |\
125 				 FAN_ALL_PERM_EVENTS |\
126 				 FAN_Q_OVERFLOW)
127 
128 #define FANOTIFY_METADATA_VERSION	3
129 
130 struct fanotify_event_metadata {
131 	__u32 event_len;
132 	__u8 vers;
133 	__u8 reserved;
134 	__u16 metadata_len;
135 	__aligned_u64 mask;
136 	__s32 fd;
137 	__s32 pid;
138 };
139 
140 #define FAN_EVENT_INFO_TYPE_FID		1
141 #define FAN_EVENT_INFO_TYPE_DFID_NAME	2
142 #define FAN_EVENT_INFO_TYPE_DFID	3
143 #define FAN_EVENT_INFO_TYPE_PIDFD	4
144 #define FAN_EVENT_INFO_TYPE_ERROR	5
145 
146 /* Special info types for FAN_RENAME */
147 #define FAN_EVENT_INFO_TYPE_OLD_DFID_NAME	10
148 /* Reserved for FAN_EVENT_INFO_TYPE_OLD_DFID	11 */
149 #define FAN_EVENT_INFO_TYPE_NEW_DFID_NAME	12
150 /* Reserved for FAN_EVENT_INFO_TYPE_NEW_DFID	13 */
151 
152 /* Variable length info record following event metadata */
153 struct fanotify_event_info_header {
154 	__u8 info_type;
155 	__u8 pad;
156 	__u16 len;
157 };
158 
159 /*
160  * Unique file identifier info record.
161  * This structure is used for records of types FAN_EVENT_INFO_TYPE_FID,
162  * FAN_EVENT_INFO_TYPE_DFID and FAN_EVENT_INFO_TYPE_DFID_NAME.
163  * For FAN_EVENT_INFO_TYPE_DFID_NAME there is additionally a null terminated
164  * name immediately after the file handle.
165  */
166 struct fanotify_event_info_fid {
167 	struct fanotify_event_info_header hdr;
168 	__kernel_fsid_t fsid;
169 	/*
170 	 * Following is an opaque struct file_handle that can be passed as
171 	 * an argument to open_by_handle_at(2).
172 	 */
173 	unsigned char handle[];
174 };
175 
176 /*
177  * This structure is used for info records of type FAN_EVENT_INFO_TYPE_PIDFD.
178  * It holds a pidfd for the pid that was responsible for generating an event.
179  */
180 struct fanotify_event_info_pidfd {
181 	struct fanotify_event_info_header hdr;
182 	__s32 pidfd;
183 };
184 
185 struct fanotify_event_info_error {
186 	struct fanotify_event_info_header hdr;
187 	__s32 error;
188 	__u32 error_count;
189 };
190 
191 /*
192  * User space may need to record additional information about its decision.
193  * The extra information type records what kind of information is included.
194  * The default is none. We also define an extra information buffer whose
195  * size is determined by the extra information type.
196  *
197  * If the information type is Audit Rule, then the information following
198  * is the rule number that triggered the user space decision that
199  * requires auditing.
200  */
201 
202 #define FAN_RESPONSE_INFO_NONE		0
203 #define FAN_RESPONSE_INFO_AUDIT_RULE	1
204 
205 struct fanotify_response {
206 	__s32 fd;
207 	__u32 response;
208 };
209 
210 struct fanotify_response_info_header {
211 	__u8 type;
212 	__u8 pad;
213 	__u16 len;
214 };
215 
216 struct fanotify_response_info_audit_rule {
217 	struct fanotify_response_info_header hdr;
218 	__u32 rule_number;
219 	__u32 subj_trust;
220 	__u32 obj_trust;
221 };
222 
223 /* Legit userspace responses to a _PERM event */
224 #define FAN_ALLOW	0x01
225 #define FAN_DENY	0x02
226 #define FAN_AUDIT	0x10	/* Bitmask to create audit record for result */
227 #define FAN_INFO	0x20	/* Bitmask to indicate additional information */
228 
229 /* No fd set in event */
230 #define FAN_NOFD	-1
231 #define FAN_NOPIDFD	FAN_NOFD
232 #define FAN_EPIDFD	-2
233 
234 /* Helper functions to deal with fanotify_event_metadata buffers */
235 #define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata))
236 
237 #define FAN_EVENT_NEXT(meta, len) ((len) -= (meta)->event_len, \
238 				   (struct fanotify_event_metadata*)(((char *)(meta)) + \
239 				   (meta)->event_len))
240 
241 #define FAN_EVENT_OK(meta, len)	((long)(len) >= (long)FAN_EVENT_METADATA_LEN && \
242 				(long)(meta)->event_len >= (long)FAN_EVENT_METADATA_LEN && \
243 				(long)(meta)->event_len <= (long)(len))
244 
245 #endif /* _UAPI_LINUX_FANOTIFY_H */
246