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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/notify/fanotify/fanotify.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/notify/fanotify/fanotify.h')
-rw-r--r--fs/notify/fanotify/fanotify.h500
1 files changed, 500 insertions, 0 deletions
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
new file mode 100644
index 000000000..57f51a9a3
--- /dev/null
+++ b/fs/notify/fanotify/fanotify.h
@@ -0,0 +1,500 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/fsnotify_backend.h>
+#include <linux/path.h>
+#include <linux/slab.h>
+#include <linux/exportfs.h>
+#include <linux/hashtable.h>
+
+extern struct kmem_cache *fanotify_mark_cache;
+extern struct kmem_cache *fanotify_fid_event_cachep;
+extern struct kmem_cache *fanotify_path_event_cachep;
+extern struct kmem_cache *fanotify_perm_event_cachep;
+
+/* Possible states of the permission event */
+enum {
+ FAN_EVENT_INIT,
+ FAN_EVENT_REPORTED,
+ FAN_EVENT_ANSWERED,
+ FAN_EVENT_CANCELED,
+};
+
+/*
+ * 3 dwords are sufficient for most local fs (64bit ino, 32bit generation).
+ * fh buf should be dword aligned. On 64bit arch, the ext_buf pointer is
+ * stored in either the first or last 2 dwords.
+ */
+#define FANOTIFY_INLINE_FH_LEN (3 << 2)
+#define FANOTIFY_FH_HDR_LEN offsetof(struct fanotify_fh, buf)
+
+/* Fixed size struct for file handle */
+struct fanotify_fh {
+ u8 type;
+ u8 len;
+#define FANOTIFY_FH_FLAG_EXT_BUF 1
+ u8 flags;
+ u8 pad;
+ unsigned char buf[];
+} __aligned(4);
+
+/* Variable size struct for dir file handle + child file handle + name */
+struct fanotify_info {
+ /* size of dir_fh/file_fh including fanotify_fh hdr size */
+ u8 dir_fh_totlen;
+ u8 dir2_fh_totlen;
+ u8 file_fh_totlen;
+ u8 name_len;
+ u8 name2_len;
+ u8 pad[3];
+ unsigned char buf[];
+ /*
+ * (struct fanotify_fh) dir_fh starts at buf[0]
+ * (optional) dir2_fh starts at buf[dir_fh_totlen]
+ * (optional) file_fh starts at buf[dir_fh_totlen + dir2_fh_totlen]
+ * name starts at buf[dir_fh_totlen + dir2_fh_totlen + file_fh_totlen]
+ * ...
+ */
+#define FANOTIFY_DIR_FH_SIZE(info) ((info)->dir_fh_totlen)
+#define FANOTIFY_DIR2_FH_SIZE(info) ((info)->dir2_fh_totlen)
+#define FANOTIFY_FILE_FH_SIZE(info) ((info)->file_fh_totlen)
+#define FANOTIFY_NAME_SIZE(info) ((info)->name_len + 1)
+#define FANOTIFY_NAME2_SIZE(info) ((info)->name2_len + 1)
+
+#define FANOTIFY_DIR_FH_OFFSET(info) 0
+#define FANOTIFY_DIR2_FH_OFFSET(info) \
+ (FANOTIFY_DIR_FH_OFFSET(info) + FANOTIFY_DIR_FH_SIZE(info))
+#define FANOTIFY_FILE_FH_OFFSET(info) \
+ (FANOTIFY_DIR2_FH_OFFSET(info) + FANOTIFY_DIR2_FH_SIZE(info))
+#define FANOTIFY_NAME_OFFSET(info) \
+ (FANOTIFY_FILE_FH_OFFSET(info) + FANOTIFY_FILE_FH_SIZE(info))
+#define FANOTIFY_NAME2_OFFSET(info) \
+ (FANOTIFY_NAME_OFFSET(info) + FANOTIFY_NAME_SIZE(info))
+
+#define FANOTIFY_DIR_FH_BUF(info) \
+ ((info)->buf + FANOTIFY_DIR_FH_OFFSET(info))
+#define FANOTIFY_DIR2_FH_BUF(info) \
+ ((info)->buf + FANOTIFY_DIR2_FH_OFFSET(info))
+#define FANOTIFY_FILE_FH_BUF(info) \
+ ((info)->buf + FANOTIFY_FILE_FH_OFFSET(info))
+#define FANOTIFY_NAME_BUF(info) \
+ ((info)->buf + FANOTIFY_NAME_OFFSET(info))
+#define FANOTIFY_NAME2_BUF(info) \
+ ((info)->buf + FANOTIFY_NAME2_OFFSET(info))
+} __aligned(4);
+
+static inline bool fanotify_fh_has_ext_buf(struct fanotify_fh *fh)
+{
+ return (fh->flags & FANOTIFY_FH_FLAG_EXT_BUF);
+}
+
+static inline char **fanotify_fh_ext_buf_ptr(struct fanotify_fh *fh)
+{
+ BUILD_BUG_ON(FANOTIFY_FH_HDR_LEN % 4);
+ BUILD_BUG_ON(__alignof__(char *) - 4 + sizeof(char *) >
+ FANOTIFY_INLINE_FH_LEN);
+ return (char **)ALIGN((unsigned long)(fh->buf), __alignof__(char *));
+}
+
+static inline void *fanotify_fh_ext_buf(struct fanotify_fh *fh)
+{
+ return *fanotify_fh_ext_buf_ptr(fh);
+}
+
+static inline void *fanotify_fh_buf(struct fanotify_fh *fh)
+{
+ return fanotify_fh_has_ext_buf(fh) ? fanotify_fh_ext_buf(fh) : fh->buf;
+}
+
+static inline int fanotify_info_dir_fh_len(struct fanotify_info *info)
+{
+ if (!info->dir_fh_totlen ||
+ WARN_ON_ONCE(info->dir_fh_totlen < FANOTIFY_FH_HDR_LEN))
+ return 0;
+
+ return info->dir_fh_totlen - FANOTIFY_FH_HDR_LEN;
+}
+
+static inline struct fanotify_fh *fanotify_info_dir_fh(struct fanotify_info *info)
+{
+ BUILD_BUG_ON(offsetof(struct fanotify_info, buf) % 4);
+
+ return (struct fanotify_fh *)FANOTIFY_DIR_FH_BUF(info);
+}
+
+static inline int fanotify_info_dir2_fh_len(struct fanotify_info *info)
+{
+ if (!info->dir2_fh_totlen ||
+ WARN_ON_ONCE(info->dir2_fh_totlen < FANOTIFY_FH_HDR_LEN))
+ return 0;
+
+ return info->dir2_fh_totlen - FANOTIFY_FH_HDR_LEN;
+}
+
+static inline struct fanotify_fh *fanotify_info_dir2_fh(struct fanotify_info *info)
+{
+ return (struct fanotify_fh *)FANOTIFY_DIR2_FH_BUF(info);
+}
+
+static inline int fanotify_info_file_fh_len(struct fanotify_info *info)
+{
+ if (!info->file_fh_totlen ||
+ WARN_ON_ONCE(info->file_fh_totlen < FANOTIFY_FH_HDR_LEN))
+ return 0;
+
+ return info->file_fh_totlen - FANOTIFY_FH_HDR_LEN;
+}
+
+static inline struct fanotify_fh *fanotify_info_file_fh(struct fanotify_info *info)
+{
+ return (struct fanotify_fh *)FANOTIFY_FILE_FH_BUF(info);
+}
+
+static inline char *fanotify_info_name(struct fanotify_info *info)
+{
+ if (!info->name_len)
+ return NULL;
+
+ return FANOTIFY_NAME_BUF(info);
+}
+
+static inline char *fanotify_info_name2(struct fanotify_info *info)
+{
+ if (!info->name2_len)
+ return NULL;
+
+ return FANOTIFY_NAME2_BUF(info);
+}
+
+static inline void fanotify_info_init(struct fanotify_info *info)
+{
+ BUILD_BUG_ON(FANOTIFY_FH_HDR_LEN + MAX_HANDLE_SZ > U8_MAX);
+ BUILD_BUG_ON(NAME_MAX > U8_MAX);
+
+ info->dir_fh_totlen = 0;
+ info->dir2_fh_totlen = 0;
+ info->file_fh_totlen = 0;
+ info->name_len = 0;
+ info->name2_len = 0;
+}
+
+/* These set/copy helpers MUST be called by order */
+static inline void fanotify_info_set_dir_fh(struct fanotify_info *info,
+ unsigned int totlen)
+{
+ if (WARN_ON_ONCE(info->dir2_fh_totlen > 0) ||
+ WARN_ON_ONCE(info->file_fh_totlen > 0) ||
+ WARN_ON_ONCE(info->name_len > 0) ||
+ WARN_ON_ONCE(info->name2_len > 0))
+ return;
+
+ info->dir_fh_totlen = totlen;
+}
+
+static inline void fanotify_info_set_dir2_fh(struct fanotify_info *info,
+ unsigned int totlen)
+{
+ if (WARN_ON_ONCE(info->file_fh_totlen > 0) ||
+ WARN_ON_ONCE(info->name_len > 0) ||
+ WARN_ON_ONCE(info->name2_len > 0))
+ return;
+
+ info->dir2_fh_totlen = totlen;
+}
+
+static inline void fanotify_info_set_file_fh(struct fanotify_info *info,
+ unsigned int totlen)
+{
+ if (WARN_ON_ONCE(info->name_len > 0) ||
+ WARN_ON_ONCE(info->name2_len > 0))
+ return;
+
+ info->file_fh_totlen = totlen;
+}
+
+static inline void fanotify_info_copy_name(struct fanotify_info *info,
+ const struct qstr *name)
+{
+ if (WARN_ON_ONCE(name->len > NAME_MAX) ||
+ WARN_ON_ONCE(info->name2_len > 0))
+ return;
+
+ info->name_len = name->len;
+ strcpy(fanotify_info_name(info), name->name);
+}
+
+static inline void fanotify_info_copy_name2(struct fanotify_info *info,
+ const struct qstr *name)
+{
+ if (WARN_ON_ONCE(name->len > NAME_MAX))
+ return;
+
+ info->name2_len = name->len;
+ strcpy(fanotify_info_name2(info), name->name);
+}
+
+/*
+ * Common structure for fanotify events. Concrete structs are allocated in
+ * fanotify_handle_event() and freed when the information is retrieved by
+ * userspace. The type of event determines how it was allocated, how it will
+ * be freed and which concrete struct it may be cast to.
+ */
+enum fanotify_event_type {
+ FANOTIFY_EVENT_TYPE_FID, /* fixed length */
+ FANOTIFY_EVENT_TYPE_FID_NAME, /* variable length */
+ FANOTIFY_EVENT_TYPE_PATH,
+ FANOTIFY_EVENT_TYPE_PATH_PERM,
+ FANOTIFY_EVENT_TYPE_OVERFLOW, /* struct fanotify_event */
+ FANOTIFY_EVENT_TYPE_FS_ERROR, /* struct fanotify_error_event */
+ __FANOTIFY_EVENT_TYPE_NUM
+};
+
+#define FANOTIFY_EVENT_TYPE_BITS \
+ (ilog2(__FANOTIFY_EVENT_TYPE_NUM - 1) + 1)
+#define FANOTIFY_EVENT_HASH_BITS \
+ (32 - FANOTIFY_EVENT_TYPE_BITS)
+
+struct fanotify_event {
+ struct fsnotify_event fse;
+ struct hlist_node merge_list; /* List for hashed merge */
+ u32 mask;
+ struct {
+ unsigned int type : FANOTIFY_EVENT_TYPE_BITS;
+ unsigned int hash : FANOTIFY_EVENT_HASH_BITS;
+ };
+ struct pid *pid;
+};
+
+static inline void fanotify_init_event(struct fanotify_event *event,
+ unsigned int hash, u32 mask)
+{
+ fsnotify_init_event(&event->fse);
+ INIT_HLIST_NODE(&event->merge_list);
+ event->hash = hash;
+ event->mask = mask;
+ event->pid = NULL;
+}
+
+#define FANOTIFY_INLINE_FH(name, size) \
+struct { \
+ struct fanotify_fh (name); \
+ /* Space for object_fh.buf[] - access with fanotify_fh_buf() */ \
+ unsigned char _inline_fh_buf[(size)]; \
+}
+
+struct fanotify_fid_event {
+ struct fanotify_event fae;
+ __kernel_fsid_t fsid;
+
+ FANOTIFY_INLINE_FH(object_fh, FANOTIFY_INLINE_FH_LEN);
+};
+
+static inline struct fanotify_fid_event *
+FANOTIFY_FE(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_fid_event, fae);
+}
+
+struct fanotify_name_event {
+ struct fanotify_event fae;
+ __kernel_fsid_t fsid;
+ struct fanotify_info info;
+};
+
+static inline struct fanotify_name_event *
+FANOTIFY_NE(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_name_event, fae);
+}
+
+struct fanotify_error_event {
+ struct fanotify_event fae;
+ s32 error; /* Error reported by the Filesystem. */
+ u32 err_count; /* Suppressed errors count */
+
+ __kernel_fsid_t fsid; /* FSID this error refers to. */
+
+ FANOTIFY_INLINE_FH(object_fh, MAX_HANDLE_SZ);
+};
+
+static inline struct fanotify_error_event *
+FANOTIFY_EE(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_error_event, fae);
+}
+
+static inline __kernel_fsid_t *fanotify_event_fsid(struct fanotify_event *event)
+{
+ if (event->type == FANOTIFY_EVENT_TYPE_FID)
+ return &FANOTIFY_FE(event)->fsid;
+ else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
+ return &FANOTIFY_NE(event)->fsid;
+ else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+ return &FANOTIFY_EE(event)->fsid;
+ else
+ return NULL;
+}
+
+static inline struct fanotify_fh *fanotify_event_object_fh(
+ struct fanotify_event *event)
+{
+ if (event->type == FANOTIFY_EVENT_TYPE_FID)
+ return &FANOTIFY_FE(event)->object_fh;
+ else if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
+ return fanotify_info_file_fh(&FANOTIFY_NE(event)->info);
+ else if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+ return &FANOTIFY_EE(event)->object_fh;
+ else
+ return NULL;
+}
+
+static inline struct fanotify_info *fanotify_event_info(
+ struct fanotify_event *event)
+{
+ if (event->type == FANOTIFY_EVENT_TYPE_FID_NAME)
+ return &FANOTIFY_NE(event)->info;
+ else
+ return NULL;
+}
+
+static inline int fanotify_event_object_fh_len(struct fanotify_event *event)
+{
+ struct fanotify_info *info = fanotify_event_info(event);
+ struct fanotify_fh *fh = fanotify_event_object_fh(event);
+
+ if (info)
+ return info->file_fh_totlen ? fh->len : 0;
+ else
+ return fh ? fh->len : 0;
+}
+
+static inline int fanotify_event_dir_fh_len(struct fanotify_event *event)
+{
+ struct fanotify_info *info = fanotify_event_info(event);
+
+ return info ? fanotify_info_dir_fh_len(info) : 0;
+}
+
+static inline int fanotify_event_dir2_fh_len(struct fanotify_event *event)
+{
+ struct fanotify_info *info = fanotify_event_info(event);
+
+ return info ? fanotify_info_dir2_fh_len(info) : 0;
+}
+
+static inline bool fanotify_event_has_object_fh(struct fanotify_event *event)
+{
+ /* For error events, even zeroed fh are reported. */
+ if (event->type == FANOTIFY_EVENT_TYPE_FS_ERROR)
+ return true;
+ return fanotify_event_object_fh_len(event) > 0;
+}
+
+static inline bool fanotify_event_has_dir_fh(struct fanotify_event *event)
+{
+ return fanotify_event_dir_fh_len(event) > 0;
+}
+
+static inline bool fanotify_event_has_dir2_fh(struct fanotify_event *event)
+{
+ return fanotify_event_dir2_fh_len(event) > 0;
+}
+
+static inline bool fanotify_event_has_any_dir_fh(struct fanotify_event *event)
+{
+ return fanotify_event_has_dir_fh(event) ||
+ fanotify_event_has_dir2_fh(event);
+}
+
+struct fanotify_path_event {
+ struct fanotify_event fae;
+ struct path path;
+};
+
+static inline struct fanotify_path_event *
+FANOTIFY_PE(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_path_event, fae);
+}
+
+/*
+ * Structure for permission fanotify events. It gets allocated and freed in
+ * fanotify_handle_event() since we wait there for user response. When the
+ * information is retrieved by userspace the structure is moved from
+ * group->notification_list to group->fanotify_data.access_list to wait for
+ * user response.
+ */
+struct fanotify_perm_event {
+ struct fanotify_event fae;
+ struct path path;
+ unsigned short response; /* userspace answer to the event */
+ unsigned short state; /* state of the event */
+ int fd; /* fd we passed to userspace for this event */
+};
+
+static inline struct fanotify_perm_event *
+FANOTIFY_PERM(struct fanotify_event *event)
+{
+ return container_of(event, struct fanotify_perm_event, fae);
+}
+
+static inline bool fanotify_is_perm_event(u32 mask)
+{
+ return IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS) &&
+ mask & FANOTIFY_PERM_EVENTS;
+}
+
+static inline struct fanotify_event *FANOTIFY_E(struct fsnotify_event *fse)
+{
+ return container_of(fse, struct fanotify_event, fse);
+}
+
+static inline bool fanotify_is_error_event(u32 mask)
+{
+ return mask & FAN_FS_ERROR;
+}
+
+static inline const struct path *fanotify_event_path(struct fanotify_event *event)
+{
+ if (event->type == FANOTIFY_EVENT_TYPE_PATH)
+ return &FANOTIFY_PE(event)->path;
+ else if (event->type == FANOTIFY_EVENT_TYPE_PATH_PERM)
+ return &FANOTIFY_PERM(event)->path;
+ else
+ return NULL;
+}
+
+/*
+ * Use 128 size hash table to speed up events merge.
+ */
+#define FANOTIFY_HTABLE_BITS (7)
+#define FANOTIFY_HTABLE_SIZE (1 << FANOTIFY_HTABLE_BITS)
+#define FANOTIFY_HTABLE_MASK (FANOTIFY_HTABLE_SIZE - 1)
+
+/*
+ * Permission events and overflow event do not get merged - don't hash them.
+ */
+static inline bool fanotify_is_hashed_event(u32 mask)
+{
+ return !(fanotify_is_perm_event(mask) ||
+ fsnotify_is_overflow_event(mask));
+}
+
+static inline unsigned int fanotify_event_hash_bucket(
+ struct fsnotify_group *group,
+ struct fanotify_event *event)
+{
+ return event->hash & FANOTIFY_HTABLE_MASK;
+}
+
+static inline unsigned int fanotify_mark_user_flags(struct fsnotify_mark *mark)
+{
+ unsigned int mflags = 0;
+
+ if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
+ mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
+ if (mark->flags & FSNOTIFY_MARK_FLAG_NO_IREF)
+ mflags |= FAN_MARK_EVICTABLE;
+ if (mark->flags & FSNOTIFY_MARK_FLAG_HAS_IGNORE_FLAGS)
+ mflags |= FAN_MARK_IGNORE;
+
+ return mflags;
+}