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gems-kernel/source/THIRDPARTY/xnu/bsd/vfs/vfs_fsevents.c
Sam Sneed f5727805f2 add darwin/xnu functionality
2024-06-03 11:29:39 -05:00

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/*
* Copyright (c) 2004-2021 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <stdarg.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/event.h> // for kqueue related stuff
#include <sys/fsevents.h>
#if CONFIG_FSE
#include <sys/namei.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/file_internal.h>
#include <sys/stat.h>
#include <sys/vnode_internal.h>
#include <sys/mount_internal.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/uio.h>
#include <kern/kalloc.h>
#include <sys/dirent.h>
#include <sys/attr.h>
#include <sys/sysctl.h>
#include <sys/ubc.h>
#include <machine/cons.h>
#include <miscfs/specfs/specdev.h>
#include <miscfs/devfs/devfs.h>
#include <sys/filio.h>
#include <kern/locks.h>
#include <libkern/OSAtomic.h>
#include <kern/zalloc.h>
#include <mach/mach_time.h>
#include <kern/thread_call.h>
#include <kern/clock.h>
#include <IOKit/IOBSD.h>
#include <security/audit/audit.h>
#include <bsm/audit_kevents.h>
#include <pexpert/pexpert.h>
#include <libkern/section_keywords.h>
typedef struct kfs_event {
LIST_ENTRY(kfs_event) kevent_list;
uint64_t abstime; // when this event happened (mach_absolute_time())
int16_t type; // type code of this event
uint16_t flags; // per-event flags
int32_t refcount; // number of clients referencing this
pid_t pid;
int32_t spare;
union {
struct regular_event {
// This must match the layout of fse_info
// exactly, except for the "nlink" field is
// not included here. See copy_out_kfse()
// for all of the sordid details, and also
// the _Static_assert() statements below.
ino64_t ino;
dev_t dev;
int32_t mode;
uid_t uid;
uint32_t document_id;
struct kfs_event *dest; // if this is a two-file op
const char *str;
uint16_t len;
} regular_event;
struct {
ino64_t src_ino;
ino64_t dst_ino;
uint64_t docid;
dev_t dev;
} docid_event;
struct {
uint32_t version;
dev_t dev;
ino64_t ino;
uint64_t origin_id;
uint64_t age;
uint32_t use_state;
uint32_t urgency;
uint64_t size;
} activity_event;
struct {
audit_token_t audit_token;
const char *str;
uint16_t len;
} access_granted_event;
};
} kfs_event;
_Static_assert(offsetof(struct regular_event, ino) == offsetof(fse_info, ino),
"kfs_event and fse_info out-of-sync");
_Static_assert(offsetof(struct regular_event, dev) == offsetof(fse_info, dev),
"kfs_event and fse_info out-of-sync");
_Static_assert(offsetof(struct regular_event, mode) == offsetof(fse_info, mode),
"kfs_event and fse_info out-of-sync");
_Static_assert(offsetof(struct regular_event, uid) == offsetof(fse_info, uid),
"kfs_event and fse_info out-of-sync");
_Static_assert(offsetof(struct regular_event, document_id) == offsetof(fse_info, document_id),
"kfs_event and fse_info out-of-sync");
#define KFSE_INFO_COPYSIZE offsetof(fse_info, nlink)
// flags for the flags field
#define KFSE_COMBINED_EVENTS 0x0001
#define KFSE_CONTAINS_DROPPED_EVENTS 0x0002
#define KFSE_ON_LIST 0x0004
#define KFSE_BEING_CREATED 0x0008
LIST_HEAD(kfse_list, kfs_event) kfse_list_head = LIST_HEAD_INITIALIZER(x);
int num_events_outstanding = 0;
int num_pending_rename = 0;
struct fsevent_handle;
typedef struct fs_event_watcher {
int8_t *event_list; // the events we're interested in
int32_t num_events;
dev_t *devices_not_to_watch;// report events from devices not in this list
uint32_t num_devices;
int32_t flags;
kfs_event **event_queue;
int32_t eventq_size; // number of event pointers in queue
int32_t num_readers;
int32_t rd; // read index into the event_queue
int32_t wr; // write index into the event_queue
int32_t blockers;
int32_t my_id;
uint32_t num_dropped;
uint64_t max_event_id;
struct fsevent_handle *fseh;
pid_t pid;
char proc_name[(2 * MAXCOMLEN) + 1];
} fs_event_watcher;
// fs_event_watcher flags
#define WATCHER_DROPPED_EVENTS 0x0001
#define WATCHER_CLOSING 0x0002
#define WATCHER_WANTS_COMPACT_EVENTS 0x0004
#define WATCHER_WANTS_EXTENDED_INFO 0x0008
#define WATCHER_APPLE_SYSTEM_SERVICE 0x0010 // fseventsd, coreservicesd, mds, revisiond
#define MAX_WATCHERS 8
static fs_event_watcher *watcher_table[MAX_WATCHERS];
#define DEFAULT_MAX_KFS_EVENTS 4096
static int max_kfs_events = DEFAULT_MAX_KFS_EVENTS;
// we allocate kfs_event structures out of this zone
static zone_t event_zone;
static int fs_event_init = 0;
//
// this array records whether anyone is interested in a
// particular type of event. if no one is, we bail out
// early from the event delivery
//
static int16_t fs_event_type_watchers[FSE_MAX_EVENTS];
// the device currently being unmounted:
static dev_t fsevent_unmount_dev = 0;
// how many ACKs are still outstanding:
static int fsevent_unmount_ack_count = 0;
static int watcher_add_event(fs_event_watcher *watcher, kfs_event *kfse);
static void fsevents_wakeup(fs_event_watcher *watcher);
//
// Locks
//
static LCK_ATTR_DECLARE(fsevent_lock_attr, 0, 0);
static LCK_GRP_DECLARE(fsevent_mutex_group, "fsevent-mutex");
static LCK_GRP_DECLARE(fsevent_rw_group, "fsevent-rw");
static LCK_RW_DECLARE_ATTR(event_handling_lock, // handles locking for event manipulation and recycling
&fsevent_rw_group, &fsevent_lock_attr);
static LCK_MTX_DECLARE_ATTR(watch_table_lock,
&fsevent_mutex_group, &fsevent_lock_attr);
static LCK_MTX_DECLARE_ATTR(event_buf_lock,
&fsevent_mutex_group, &fsevent_lock_attr);
static LCK_MTX_DECLARE_ATTR(event_writer_lock,
&fsevent_mutex_group, &fsevent_lock_attr);
/* Explicitly declare qsort so compiler doesn't complain */
__private_extern__ void qsort(
void * array,
size_t nmembers,
size_t member_size,
int (*)(const void *, const void *));
static int
is_ignored_directory(const char *path)
{
if (!path) {
return 0;
}
#define IS_TLD(x) strnstr(__DECONST(char *, path), x, MAXPATHLEN)
if (IS_TLD("/.Spotlight-V100/") ||
IS_TLD("/.MobileBackups/") ||
IS_TLD("/Backups.backupdb/")) {
return 1;
}
#undef IS_TLD
return 0;
}
static void
fsevents_internal_init(void)
{
int i;
if (fs_event_init++ != 0) {
return;
}
for (i = 0; i < FSE_MAX_EVENTS; i++) {
fs_event_type_watchers[i] = 0;
}
memset(watcher_table, 0, sizeof(watcher_table));
PE_get_default("kern.maxkfsevents", &max_kfs_events, sizeof(max_kfs_events));
event_zone = zone_create_ext("fs-event-buf", sizeof(kfs_event),
ZC_NOGC | ZC_NOCALLOUT, ZONE_ID_ANY, ^(zone_t z) {
// mark the zone as exhaustible so that it will not
// ever grow beyond what we initially filled it with
zone_set_exhaustible(z, max_kfs_events, /* exhausts */ true);
});
zone_fill_initially(event_zone, max_kfs_events);
}
static void
lock_watch_table(void)
{
lck_mtx_lock(&watch_table_lock);
}
static void
unlock_watch_table(void)
{
lck_mtx_unlock(&watch_table_lock);
}
static void
lock_fs_event_list(void)
{
lck_mtx_lock(&event_buf_lock);
}
static void
unlock_fs_event_list(void)
{
lck_mtx_unlock(&event_buf_lock);
}
// forward prototype
static void release_event_ref(kfs_event *kfse);
static boolean_t
watcher_cares_about_dev(fs_event_watcher *watcher, dev_t dev)
{
unsigned int i;
// if devices_not_to_watch is NULL then we care about all
// events from all devices
if (watcher->devices_not_to_watch == NULL) {
return true;
}
for (i = 0; i < watcher->num_devices; i++) {
if (dev == watcher->devices_not_to_watch[i]) {
// found a match! that means we do not
// want events from this device.
return false;
}
}
// if we're here it's not in the devices_not_to_watch[]
// list so that means we do care about it
return true;
}
int
need_fsevent(int type, vnode_t vp)
{
if (type >= 0 && type < FSE_MAX_EVENTS && fs_event_type_watchers[type] == 0) {
return 0;
}
// events in /dev aren't really interesting...
if (vp->v_tag == VT_DEVFS) {
return 0;
}
return 1;
}
#define is_throw_away(x) ((x) == FSE_STAT_CHANGED || (x) == FSE_CONTENT_MODIFIED)
int num_dropped = 0;
static struct timeval last_print;
//
// These variables are used to track coalescing multiple identical
// events for the same vnode/pathname. If we get the same event
// type and same vnode/pathname as the previous event, we just drop
// the event since it's superfluous. This improves some micro-
// benchmarks considerably and actually has a real-world impact on
// tests like a Finder copy where multiple stat-changed events can
// get coalesced.
//
static int last_event_type = -1;
static void *last_ptr = NULL;
static char last_str[MAXPATHLEN];
static int last_nlen = 0;
static int last_vid = -1;
static uint64_t last_coalesced_time = 0;
static void *last_event_ptr = NULL;
static pid_t last_pid = -1;
int last_coalesced = 0;
static mach_timebase_info_data_t sTimebaseInfo = { 0, 0 };
#define MAX_HARDLINK_NOTIFICATIONS 128
static inline void
kfse_init(kfs_event *kfse, int type, uint64_t time, proc_t p)
{
memset(kfse, 0, sizeof(*kfse));
kfse->refcount = 1;
kfse->type = (int16_t)type;
kfse->abstime = time;
kfse->pid = proc_getpid(p);
OSBitOrAtomic16(KFSE_BEING_CREATED, &kfse->flags);
}
int
add_fsevent(int type, vfs_context_t ctx, ...)
{
struct proc *p = vfs_context_proc(ctx);
int i, arg_type, ret;
kfs_event *kfse, *kfse_dest = NULL, *cur;
fs_event_watcher *watcher;
va_list ap;
int error = 0, did_alloc = 0;
int64_t orig_linkcount = -1;
dev_t dev = 0;
uint64_t now, elapsed;
uint64_t orig_linkid = 0, next_linkid = 0;
uint64_t link_parentid = 0;
char *pathbuff = NULL, *path_override = NULL;
char *link_name = NULL;
vnode_t link_vp = NULL;
int pathbuff_len = 0;
uthread_t ut = get_bsdthread_info(current_thread());
bool do_all_links = true;
bool do_cache_reset = false;
if (type == FSE_CONTENT_MODIFIED_NO_HLINK) {
do_all_links = false;
type = FSE_CONTENT_MODIFIED;
}
restart:
va_start(ap, ctx);
// ignore bogus event types..
if (type < 0 || type >= FSE_MAX_EVENTS) {
return EINVAL;
}
// if no one cares about this type of event, bail out
if (fs_event_type_watchers[type] == 0) {
va_end(ap);
return 0;
}
now = mach_absolute_time();
// find a free event and snag it for our use
// NOTE: do not do anything that would block until
// the lock is dropped.
lock_fs_event_list();
//
// check if this event is identical to the previous one...
// (as long as it's not an event type that can never be the
// same as a previous event)
//
if (path_override == NULL &&
type != FSE_CREATE_FILE &&
type != FSE_DELETE &&
type != FSE_RENAME &&
type != FSE_EXCHANGE &&
type != FSE_CHOWN &&
type != FSE_DOCID_CHANGED &&
type != FSE_DOCID_CREATED &&
type != FSE_CLONE &&
type != FSE_ACTIVITY &&
// don't coalesce FSE_ACCESS_GRANTED because it could
// have been granted to a different process.
type != FSE_ACCESS_GRANTED) {
void *ptr = NULL;
int vid = 0, was_str = 0, nlen = 0;
for (arg_type = va_arg(ap, int32_t); arg_type != FSE_ARG_DONE; arg_type = va_arg(ap, int32_t)) {
switch (arg_type) {
case FSE_ARG_VNODE: {
ptr = va_arg(ap, void *);
vid = vnode_vid((struct vnode *)ptr);
last_str[0] = '\0';
break;
}
case FSE_ARG_STRING: {
nlen = va_arg(ap, int32_t);
ptr = va_arg(ap, void *);
was_str = 1;
break;
}
}
if (ptr != NULL) {
break;
}
}
if (sTimebaseInfo.denom == 0) {
(void) clock_timebase_info(&sTimebaseInfo);
}
elapsed = (now - last_coalesced_time);
if (sTimebaseInfo.denom != sTimebaseInfo.numer) {
if (sTimebaseInfo.denom == 1) {
elapsed *= sTimebaseInfo.numer;
} else {
// this could overflow... the worst that will happen is that we'll
// send (or not send) an extra event so I'm not going to worry about
// doing the math right like dtrace_abs_to_nano() does.
elapsed = (elapsed * sTimebaseInfo.numer) / (uint64_t)sTimebaseInfo.denom;
}
}
if (type == last_event_type
&& (elapsed < 1000000000)
&& (last_pid == proc_getpid(p))
&&
((vid && vid == last_vid && last_ptr == ptr)
||
(last_str[0] && last_nlen == nlen && ptr && strcmp(last_str, ptr) == 0))
) {
last_coalesced++;
unlock_fs_event_list();
va_end(ap);
return 0;
} else {
last_ptr = ptr;
if (ptr && was_str) {
strlcpy(last_str, ptr, sizeof(last_str));
}
last_nlen = nlen;
last_vid = vid;
last_event_type = type;
last_coalesced_time = now;
last_pid = proc_getpid(p);
}
}
va_start(ap, ctx);
kfse = zalloc_noblock(event_zone);
if (kfse && (type == FSE_RENAME || type == FSE_EXCHANGE || type == FSE_CLONE)) {
kfse_dest = zalloc_noblock(event_zone);
if (kfse_dest == NULL) {
did_alloc = 1;
zfree(event_zone, kfse);
kfse = NULL;
}
}
if (kfse == NULL) { // yikes! no free events
unlock_fs_event_list();
lock_watch_table();
for (i = 0; i < MAX_WATCHERS; i++) {
watcher = watcher_table[i];
if (watcher == NULL) {
continue;
}
watcher->flags |= WATCHER_DROPPED_EVENTS;
fsevents_wakeup(watcher);
}
unlock_watch_table();
{
struct timeval current_tv;
num_dropped++;
// only print a message at most once every 5 seconds
microuptime(&current_tv);
if ((current_tv.tv_sec - last_print.tv_sec) > 10) {
int ii;
void *junkptr = zalloc_noblock(event_zone), *listhead = kfse_list_head.lh_first;
printf("add_fsevent: event queue is full! dropping events (num dropped events: %d; num events outstanding: %d).\n", num_dropped, num_events_outstanding);
printf("add_fsevent: kfse_list head %p ; num_pending_rename %d\n", listhead, num_pending_rename);
printf("add_fsevent: zalloc sez: %p\n", junkptr);
printf("add_fsevent: event_zone info: %d 0x%x\n", ((int *)event_zone)[0], ((int *)event_zone)[1]);
lock_watch_table();
for (ii = 0; ii < MAX_WATCHERS; ii++) {
if (watcher_table[ii] == NULL) {
continue;
}
printf("add_fsevent: watcher %s %p: rd %4d wr %4d q_size %4d flags 0x%x\n",
watcher_table[ii]->proc_name,
watcher_table[ii],
watcher_table[ii]->rd, watcher_table[ii]->wr,
watcher_table[ii]->eventq_size, watcher_table[ii]->flags);
}
unlock_watch_table();
last_print = current_tv;
if (junkptr) {
zfree(event_zone, junkptr);
}
}
}
if (pathbuff) {
release_pathbuff(pathbuff);
pathbuff = NULL;
}
return ENOSPC;
}
kfse_init(kfse, type, now, p);
last_event_ptr = kfse;
if (type == FSE_RENAME || type == FSE_EXCHANGE || type == FSE_CLONE) {
kfse_init(kfse_dest, type, now, p);
kfse->regular_event.dest = kfse_dest;
}
num_events_outstanding++;
if (kfse->type == FSE_RENAME) {
num_pending_rename++;
}
LIST_INSERT_HEAD(&kfse_list_head, kfse, kevent_list);
OSBitOrAtomic16(KFSE_ON_LIST, &kfse->flags);
if (kfse->refcount < 1) {
panic("add_fsevent: line %d: kfse recount %d but should be at least 1", __LINE__, kfse->refcount);
}
unlock_fs_event_list(); // at this point it's safe to unlock
//
// now process the arguments passed in and copy them into
// the kfse
//
cur = kfse;
if (type == FSE_DOCID_CREATED || type == FSE_DOCID_CHANGED) {
//
// These events are special and not like the other events.
// They only have a dev_t, src inode #, dest inode #, and
// a doc-id (va_arg'd to us in that order). If we don't
// get one of them, then the error-check filler will
// catch it.
//
do_all_links = false;
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_DEV) {
cur->docid_event.dev = (dev_t)(va_arg(ap, dev_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INO) {
cur->docid_event.src_ino =
(ino64_t)(va_arg(ap, ino64_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INO) {
cur->docid_event.dst_ino =
(ino64_t)(va_arg(ap, ino64_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT32) {
cur->docid_event.docid =
(uint64_t)va_arg(ap, uint32_t);
} else if (arg_type == FSE_ARG_INT64) {
cur->docid_event.docid =
(uint64_t)va_arg(ap, uint64_t);
}
goto done_with_args;
}
if (type == FSE_ACTIVITY) {
do_all_links = false;
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT32) {
cur->activity_event.version = (uint32_t)(va_arg(ap, uint32_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_DEV) {
cur->activity_event.dev = (dev_t)(va_arg(ap, dev_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INO) {
cur->activity_event.ino = (ino64_t)(va_arg(ap, ino64_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT64) {
cur->activity_event.origin_id = (uint64_t)(va_arg(ap, uint64_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT64) {
cur->activity_event.age = (uint64_t)(va_arg(ap, uint64_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT32) {
cur->activity_event.use_state = (uint32_t)(va_arg(ap, uint32_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT32) {
cur->activity_event.urgency = (uint32_t)(va_arg(ap, uint32_t));
}
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_INT64) {
cur->activity_event.size = (uint64_t)(va_arg(ap, uint64_t));
}
goto done_with_args;
}
#if CONFIG_FSE_ACCESS_GRANTED
if (type == FSE_ACCESS_GRANTED) {
//
// This one is also different. We get a path string
// and (maybe) and audit token. If we don't get the
// audit token, we extract is from the vfs_context_t.
//
audit_token_t *atokenp = NULL;
vnode_t vp = NULL;
char *path_str = NULL;
size_t path_strlen = 0;
void *arg;
int32_t len32;
do_all_links = false;
while ((arg_type = va_arg(ap, int32_t)) != FSE_ARG_DONE) {
switch (arg_type) {
case FSE_ARG_STRING:
len32 = va_arg(ap, int32_t);
arg = va_arg(ap, char *);
if (path_str == NULL) {
path_str = arg;
path_strlen = len32;
}
break;
case FSE_ARG_PATH:
arg = va_arg(ap, char *);
if (path_str == NULL) {
path_str = arg;
}
break;
case FSE_ARG_VNODE:
arg = va_arg(ap, vnode_t);
if (vp == NULL) {
vp = arg;
}
break;
case FSE_ARG_AUDIT_TOKEN:
arg = va_arg(ap, audit_token_t *);
if (atokenp == NULL) {
atokenp = arg;
}
break;
default:
printf("add_fsevent: FSE_ACCESS_GRANTED unknown type %d\n", arg_type);
// just skip one 32-bit word and hope we
// sync up...
(void)va_arg(ap, int32_t);
}
}
if (atokenp != NULL) {
memcpy(&cur->access_granted_event.audit_token,
atokenp,
sizeof(cur->access_granted_event.audit_token));
} else if (vfs_context_copy_audit_token(ctx,
&cur->access_granted_event.audit_token) != 0) {
OSBitOrAtomic16(KFSE_CONTAINS_DROPPED_EVENTS,
&cur->flags);
goto done_with_args;
}
//
// If we got FSE_ARG_STRING, the length includes the
// terminating NUL. If we got FSE_ARG_PATH, all we
// got was the string pointer, so get the length and
// adjust. If we didn't get either, then the caller
// needs to have provided us with a vnode, and with
// that we can get the path.
//
if (path_str != NULL) {
if (path_strlen == 0) {
path_strlen = strlen(path_str) + 1;
}
} else if (vp != NULL) {
pathbuff = get_pathbuff();
pathbuff_len = MAXPATHLEN;
pathbuff[0] = '\0';
if (vn_getpath_no_firmlink(vp, pathbuff,
&pathbuff_len) == 0) {
path_str = pathbuff;
path_strlen = pathbuff_len;
}
}
if (path_str != NULL) {
assert(path_strlen <= INT16_MAX);
cur->access_granted_event.str =
vfs_addname(path_str, (uint32_t)path_strlen, 0, 0);
if (path_str == pathbuff) {
release_pathbuff(pathbuff);
pathbuff = NULL;
}
}
if (cur->access_granted_event.str == NULL) {
OSBitOrAtomic16(KFSE_CONTAINS_DROPPED_EVENTS,
&cur->flags);
}
goto done_with_args;
}
#endif
if (type == FSE_UNMOUNT_PENDING) {
// Just a dev_t
// We use the same fields as the regular event, but we
// don't have all of the data.
do_all_links = false;
arg_type = va_arg(ap, int32_t);
if (arg_type == FSE_ARG_DEV) {
cur->regular_event.dev = (dev_t)(va_arg(ap, dev_t));
}
cur->regular_event.dest = NULL;
cur->regular_event.str = NULL;
cur->regular_event.len = 0;
goto done_with_args;
}
for (arg_type = va_arg(ap, int32_t); arg_type != FSE_ARG_DONE; arg_type = va_arg(ap, int32_t)) {
switch (arg_type) {
case FSE_ARG_VNODE: {
// this expands out into multiple arguments to the client
struct vnode *vp;
struct vnode_attr va;
if (kfse->regular_event.str != NULL) {
cur = kfse_dest;
}
vp = va_arg(ap, struct vnode *);
if (vp == NULL) {
panic("add_fsevent: you can't pass me a NULL vnode ptr (type %d)!",
cur->type);
}
VATTR_INIT(&va);
VATTR_WANTED(&va, va_fsid);
VATTR_WANTED(&va, va_fileid);
VATTR_WANTED(&va, va_mode);
VATTR_WANTED(&va, va_uid);
VATTR_WANTED(&va, va_document_id);
VATTR_WANTED(&va, va_nlink);
if ((ret = vnode_getattr(vp, &va, vfs_context_kernel())) != 0) {
// printf("add_fsevent: failed to getattr on vp %p (%d)\n", cur->fref.vp, ret);
cur->regular_event.str = NULL;
error = EINVAL;
goto clean_up;
}
cur->regular_event.dev = dev = (dev_t)va.va_fsid;
cur->regular_event.ino = (ino64_t)va.va_fileid;
cur->regular_event.mode = (int32_t)vnode_vttoif(vnode_vtype(vp)) | va.va_mode;
cur->regular_event.uid = va.va_uid;
cur->regular_event.document_id = va.va_document_id;
if (vp->v_flag & VISHARDLINK) {
cur->regular_event.mode |= FSE_MODE_HLINK;
if ((vp->v_type == VDIR && va.va_dirlinkcount == 0) || (vp->v_type == VREG && va.va_nlink == 0)) {
cur->regular_event.mode |= FSE_MODE_LAST_HLINK;
}
if (orig_linkid == 0) {
orig_linkid = cur->regular_event.ino;
orig_linkcount = MIN(va.va_nlink, MAX_HARDLINK_NOTIFICATIONS);
link_vp = vp;
if (vp->v_mount->mnt_kern_flag & MNTK_PATH_FROM_ID && !link_name) {
VATTR_INIT(&va);
VATTR_WANTED(&va, va_parentid);
VATTR_WANTED(&va, va_name);
link_name = zalloc(ZV_NAMEI);
va.va_name = link_name;
if ((ret = vnode_getattr(vp, &va, vfs_context_kernel()) != 0) ||
!(VATTR_IS_SUPPORTED(&va, va_name)) ||
!(VATTR_IS_SUPPORTED(&va, va_parentid))) {
zfree(ZV_NAMEI, link_name);
link_name = NULL;
}
if (link_name) {
link_parentid = va.va_parentid;
}
va.va_name = NULL;
}
}
}
// if we haven't gotten the path yet, get it.
if (pathbuff == NULL && path_override == NULL) {
pathbuff = get_pathbuff();
pathbuff_len = MAXPATHLEN;
pathbuff[0] = '\0';
if ((ret = vn_getpath_no_firmlink(vp, pathbuff, &pathbuff_len)) != 0 || pathbuff[0] == '\0') {
OSBitOrAtomic16(KFSE_CONTAINS_DROPPED_EVENTS,
&cur->flags);
do {
if (vp->v_parent != NULL) {
vp = vp->v_parent;
} else if (vp->v_mount) {
strlcpy(pathbuff, vp->v_mount->mnt_vfsstat.f_mntonname, MAXPATHLEN);
break;
} else {
vp = NULL;
}
if (vp == NULL) {
break;
}
pathbuff_len = MAXPATHLEN;
ret = vn_getpath_no_firmlink(vp, pathbuff, &pathbuff_len);
} while (ret == ENOSPC);
if (ret != 0 || vp == NULL) {
error = ENOENT;
goto clean_up;
}
}
} else if (path_override) {
pathbuff = path_override;
pathbuff_len = (int)strlen(path_override) + 1;
} else {
strlcpy(pathbuff, "NOPATH", MAXPATHLEN);
pathbuff_len = (int)strlen(pathbuff) + 1;
}
// store the path by adding it to the global string table
cur->regular_event.len = (u_int16_t)pathbuff_len;
cur->regular_event.str =
vfs_addname(pathbuff, pathbuff_len, 0, 0);
if (cur->regular_event.str == NULL ||
cur->regular_event.str[0] == '\0') {
panic("add_fsevent: was not able to add path %s to event %p.", pathbuff, cur);
}
if (pathbuff != path_override) {
release_pathbuff(pathbuff);
}
pathbuff = NULL;
break;
}
case FSE_ARG_FINFO: {
fse_info *fse;
fse = va_arg(ap, fse_info *);
cur->regular_event.dev = dev = (dev_t)fse->dev;
cur->regular_event.ino = (ino64_t)fse->ino;
cur->regular_event.mode = (int32_t)fse->mode;
cur->regular_event.uid = (uid_t)fse->uid;
cur->regular_event.document_id = (uint32_t)fse->document_id;
// if it's a hard-link and this is the last link, flag it
if (fse->mode & FSE_MODE_HLINK) {
if (fse->nlink == 0) {
cur->regular_event.mode |= FSE_MODE_LAST_HLINK;
}
if (orig_linkid == 0) {
orig_linkid = cur->regular_event.ino;
orig_linkcount = MIN(fse->nlink, MAX_HARDLINK_NOTIFICATIONS);
}
}
if (cur->regular_event.mode & FSE_TRUNCATED_PATH) {
OSBitOrAtomic16(KFSE_CONTAINS_DROPPED_EVENTS,
&cur->flags);
cur->regular_event.mode &= ~FSE_TRUNCATED_PATH;
}
break;
}
case FSE_ARG_STRING:
if (kfse->regular_event.str != NULL) {
cur = kfse_dest;
}
cur->regular_event.len =
(int16_t)(va_arg(ap, int32_t) & 0x7fff);
if (cur->regular_event.len >= 1) {
cur->regular_event.str =
vfs_addname(va_arg(ap, char *),
cur->regular_event.len, 0, 0);
} else {
printf("add_fsevent: funny looking string length: %d\n", (int)cur->regular_event.len);
cur->regular_event.len = 2;
cur->regular_event.str = vfs_addname("/",
cur->regular_event.len, 0, 0);
}
if (cur->regular_event.str[0] == 0) {
printf("add_fsevent: bogus looking string (len %d)\n", cur->regular_event.len);
}
break;
case FSE_ARG_INT32: {
uint32_t ival = (uint32_t)va_arg(ap, int32_t);
kfse->regular_event.uid = ival;
break;
}
default:
printf("add_fsevent: unknown type %d\n", arg_type);
// just skip one 32-bit word and hope we sync up...
(void)va_arg(ap, int32_t);
}
}
done_with_args:
va_end(ap);
// XXX Memory barrier here?
if (kfse_dest) {
OSBitAndAtomic16(~KFSE_BEING_CREATED, &kfse_dest->flags);
}
OSBitAndAtomic16(~KFSE_BEING_CREATED, &kfse->flags);
//
// now we have to go and let everyone know that
// is interested in this type of event
//
lock_watch_table();
for (i = 0; i < MAX_WATCHERS; i++) {
watcher = watcher_table[i];
if (watcher == NULL) {
continue;
}
if (type < watcher->num_events
&& watcher->event_list[type] == FSE_REPORT
&& watcher_cares_about_dev(watcher, dev)) {
if (watcher_add_event(watcher, kfse) != 0) {
watcher->num_dropped++;
continue;
}
}
// if (kfse->refcount < 1) {
// panic("add_fsevent: line %d: kfse recount %d but should be at least 1", __LINE__, kfse->refcount);
// }
}
unlock_watch_table();
clean_up:
if (pathbuff) {
release_pathbuff(pathbuff);
pathbuff = NULL;
}
// replicate events for sibling hardlinks
if (do_all_links &&
(kfse->regular_event.mode & FSE_MODE_HLINK) &&
!(kfse->regular_event.mode & FSE_MODE_LAST_HLINK) &&
(type == FSE_STAT_CHANGED ||
type == FSE_CONTENT_MODIFIED ||
type == FSE_FINDER_INFO_CHANGED ||
type == FSE_XATTR_MODIFIED)) {
if (orig_linkcount > 0 && orig_linkid != 0) {
#ifndef APFSIOC_NEXT_LINK
#define APFSIOC_NEXT_LINK _IOWR('J', 10, uint64_t)
#endif
if (path_override == NULL) {
path_override = get_pathbuff();
}
if (next_linkid == 0) {
next_linkid = orig_linkid;
}
if (link_vp) {
mount_t mp = NULL;
vnode_t mnt_rootvp = NULL;
int iret = -1;
mp = vnode_mount(link_vp);
if (mp) {
iret = VFS_ROOT(mp, &mnt_rootvp, vfs_context_kernel());
}
if (iret == 0 && mnt_rootvp) {
iret = VNOP_IOCTL(mnt_rootvp, APFSIOC_NEXT_LINK, (char *)&next_linkid, (int)0, vfs_context_kernel());
vnode_put(mnt_rootvp);
}
int32_t fsid0;
int path_override_len = MAXPATHLEN;
// continue resolving hardlink paths if there is a valid next_linkid retrieved
// file systems not supporting APFSIOC_NEXT_LINK will skip replicating events for sibling hardlinks
if (iret == 0 && next_linkid != 0) {
fsid0 = link_vp->v_mount->mnt_vfsstat.f_fsid.val[0];
ut->uu_flag |= UT_KERN_RAGE_VNODES;
if (!do_cache_reset) {
do_cache_reset = true;
}
if ((iret = fsgetpath_internal(ctx, fsid0, next_linkid, MAXPATHLEN, path_override, FSOPT_NOFIRMLINKPATH, &path_override_len)) == 0) {
orig_linkcount--;
ut->uu_flag &= ~UT_KERN_RAGE_VNODES;
if (orig_linkcount >= 0) {
release_event_ref(kfse);
goto restart;
}
} else {
// failed to get override path
// encountered a broken link or the linkid has been deleted before retrieving the path
orig_linkcount--;
ut->uu_flag &= ~UT_KERN_RAGE_VNODES;
if (orig_linkcount >= 0) {
goto clean_up;
}
}
}
}
}
}
if (link_name) {
/*
* If we call fsgetpath on all the links, it will set the link origin cache
* to the last link that the path was obtained for.
* To restore the the original link id cache in APFS we need to issue a
* lookup on the original directory + name for the link.
*/
if (do_cache_reset) {
vnode_t dvp = NULLVP;
if ((ret = VFS_VGET(link_vp->v_mount, (ino64_t)link_parentid, &dvp, vfs_context_kernel())) == 0) {
vnode_t lvp = NULLVP;
ret = vnode_lookupat(link_name, 0, &lvp, ctx, dvp);
if (!ret) {
vnode_put(lvp);
lvp = NULLVP;
}
vnode_put(dvp);
dvp = NULLVP;
}
ret = 0;
}
zfree(ZV_NAMEI, link_name);
link_name = NULL;
}
if (path_override) {
release_pathbuff(path_override);
path_override = NULL;
}
release_event_ref(kfse);
return error;
}
int
test_fse_access_granted(vnode_t vp, unsigned long type, vfs_context_t ctx)
{
audit_token_t atoken;
char *pathbuff;
int error, pathbuff_len;
if (type == 0) {
return add_fsevent(FSE_ACCESS_GRANTED, ctx,
FSE_ARG_VNODE, vp, FSE_ARG_DONE);
}
if (type == 1) {
error = vfs_context_copy_audit_token(ctx, &atoken);
if (error) {
return error;
}
return add_fsevent(FSE_ACCESS_GRANTED, ctx,
FSE_ARG_VNODE, vp, FSE_ARG_AUDIT_TOKEN, &atoken,
FSE_ARG_DONE);
}
if (type == 2 || type == 3) {
pathbuff = get_pathbuff();
pathbuff_len = MAXPATHLEN;
pathbuff[0] = '\0';
error = vn_getpath_no_firmlink(vp, pathbuff, &pathbuff_len);
if (error) {
release_pathbuff(pathbuff);
return error;
}
if (type == 2) {
error = add_fsevent(FSE_ACCESS_GRANTED, ctx,
FSE_ARG_STRING, pathbuff_len, pathbuff,
FSE_ARG_DONE);
} else {
error = add_fsevent(FSE_ACCESS_GRANTED, ctx,
FSE_ARG_PATH, pathbuff, FSE_ARG_DONE);
}
release_pathbuff(pathbuff);
return error;
}
return ENOTSUP;
}
static void
release_event_ref(kfs_event *kfse)
{
int old_refcount;
kfs_event *dest = NULL;
const char *path_str = NULL, *dest_path_str = NULL;
lock_fs_event_list();
old_refcount = OSAddAtomic(-1, &kfse->refcount);
if (old_refcount > 1) {
unlock_fs_event_list();
return;
}
if (last_event_ptr == kfse) {
last_event_ptr = NULL;
last_event_type = -1;
last_coalesced_time = 0;
}
if (kfse->refcount < 0) {
panic("release_event_ref: bogus kfse refcount %d", kfse->refcount);
}
assert(kfse->refcount == 0);
assert(kfse->type != FSE_INVALID);
//
// Get pointers to all the things so we can free without
// holding any locks.
//
if (kfse->type != FSE_DOCID_CREATED &&
kfse->type != FSE_DOCID_CHANGED &&
kfse->type != FSE_ACTIVITY) {
path_str = kfse->regular_event.str;
dest = kfse->regular_event.dest;
if (dest != NULL) {
assert(dest->type != FSE_INVALID);
if (OSAddAtomic(-1,
&kfse->regular_event.dest->refcount) == 1) {
dest_path_str = dest->regular_event.str;
} else {
dest = NULL;
}
}
}
if (dest != NULL) {
if (dest->flags & KFSE_ON_LIST) {
num_events_outstanding--;
LIST_REMOVE(dest, kevent_list);
}
}
if (kfse->flags & KFSE_ON_LIST) {
num_events_outstanding--;
LIST_REMOVE(kfse, kevent_list);
if (kfse->type == FSE_RENAME) {
num_pending_rename--;
}
}
unlock_fs_event_list();
zfree(event_zone, kfse);
if (dest != NULL) {
zfree(event_zone, dest);
}
if (path_str != NULL) {
vfs_removename(path_str);
}
if (dest_path_str != NULL) {
vfs_removename(dest_path_str);
}
}
#define FSEVENTS_WATCHER_ENTITLEMENT \
"com.apple.private.vfs.fsevents-watcher"
#define FSEVENTS_ACTIVITY_WATCHER_ENTITLEMENT \
"com.apple.private.vfs.fsevents-activity-watcher"
//
// We restrict this for two reasons:
//
// 1- So that naive processes don't get this firehose by default.
//
// 2- Because this event, when delivered to watcheres, includes the
// audit token of the process granted the access, and we don't
// want to leak that to random watchers.
//
#define FSEVENTS_ACCESS_GRANTED_WATCHER_ENTITLEMENT \
"com.apple.private.vfs.fsevents-access-granted-watcher"
static bool
watcher_is_entitled(task_t task)
{
//
// We consider a process to be entitled to watch /dev/fsevents
// if it has either FSEVENTS_WATCHER_ENTITLEMENT or
// FSEVENTS_ACCESS_GRANTED_WATCHER_ENTITLEMENT.
//
return !!(IOTaskHasEntitlement(task, FSEVENTS_WATCHER_ENTITLEMENT) ||
IOTaskHasEntitlement(task,
FSEVENTS_ACCESS_GRANTED_WATCHER_ENTITLEMENT) ||
IOTaskHasEntitlement(task,
FSEVENTS_ACTIVITY_WATCHER_ENTITLEMENT));
}
#if CONFIG_FSE_ACCESS_GRANTED
static bool
watcher_is_entitled_for_access_granted(task_t task)
{
return !!IOTaskHasEntitlement(task,
FSEVENTS_ACCESS_GRANTED_WATCHER_ENTITLEMENT);
}
#endif
static bool
watcher_is_entitled_for_activity(task_t task)
{
return !!IOTaskHasEntitlement(task,
FSEVENTS_ACTIVITY_WATCHER_ENTITLEMENT);
}
static int
add_watcher(int8_t *event_list, int32_t num_events, int32_t eventq_size, fs_event_watcher **watcher_out, void *fseh)
{
int i;
fs_event_watcher *watcher;
if (eventq_size <= 0 || eventq_size > 100 * max_kfs_events) {
eventq_size = max_kfs_events;
}
if (num_events > FSE_ACTIVITY &&
event_list[FSE_ACTIVITY] != FSE_IGNORE &&
!watcher_is_entitled_for_activity(current_task())) {
event_list[FSE_ACTIVITY] = FSE_IGNORE;
}
#if CONFIG_FSE_ACCESS_GRANTED
// If the watcher wants FSE_ACCESS_GRANTED, ensure it has the
// correct entitlement. If not, just silently drop that event.
if (num_events > FSE_ACCESS_GRANTED &&
event_list[FSE_ACCESS_GRANTED] != FSE_IGNORE &&
!watcher_is_entitled_for_access_granted(current_task())) {
event_list[FSE_ACCESS_GRANTED] = FSE_IGNORE;
}
#endif
// Note: the event_queue follows the fs_event_watcher struct
// in memory so we only have to do one allocation
watcher = kalloc_type(fs_event_watcher, kfs_event *, eventq_size, Z_WAITOK);
if (watcher == NULL) {
return ENOMEM;
}
watcher->event_list = event_list;
watcher->num_events = num_events;
watcher->devices_not_to_watch = NULL;
watcher->num_devices = 0;
watcher->flags = 0;
watcher->event_queue = (kfs_event **)&watcher[1];
watcher->eventq_size = eventq_size;
watcher->rd = 0;
watcher->wr = 0;
watcher->blockers = 0;
watcher->num_readers = 0;
watcher->max_event_id = 0;
watcher->fseh = fseh;
watcher->pid = proc_selfpid();
proc_selfname(watcher->proc_name, sizeof(watcher->proc_name));
watcher->num_dropped = 0; // XXXdbg - debugging
if (watcher_is_entitled(current_task())) {
watcher->flags |= WATCHER_APPLE_SYSTEM_SERVICE;
} else {
printf("fsevents: watcher %s (pid: %d) - Using /dev/fsevents directly is unsupported. Migrate to FSEventsFramework\n",
watcher->proc_name, watcher->pid);
}
lock_watch_table();
// find a slot for the new watcher
for (i = 0; i < MAX_WATCHERS; i++) {
if (watcher_table[i] == NULL) {
watcher->my_id = i;
watcher_table[i] = watcher;
break;
}
}
if (i >= MAX_WATCHERS) {
printf("fsevents: too many watchers!\n");
unlock_watch_table();
kfree_type(fs_event_watcher, kfs_event *, watcher->eventq_size, watcher);
return ENOSPC;
}
// now update the global list of who's interested in
// events of a particular type...
for (i = 0; i < num_events; i++) {
if (event_list[i] != FSE_IGNORE && i < FSE_MAX_EVENTS) {
fs_event_type_watchers[i]++;
}
}
unlock_watch_table();
*watcher_out = watcher;
return 0;
}
static void
remove_watcher(fs_event_watcher *target)
{
int i, j, counter = 0;
fs_event_watcher *watcher;
kfs_event *kfse;
lock_watch_table();
for (j = 0; j < MAX_WATCHERS; j++) {
watcher = watcher_table[j];
if (watcher != target) {
continue;
}
watcher_table[j] = NULL;
for (i = 0; i < watcher->num_events; i++) {
if (watcher->event_list[i] != FSE_IGNORE && i < FSE_MAX_EVENTS) {
fs_event_type_watchers[i]--;
}
}
if (watcher->flags & WATCHER_CLOSING) {
unlock_watch_table();
return;
}
// printf("fsevents: removing watcher %p (rd %d wr %d num_readers %d flags 0x%x)\n", watcher, watcher->rd, watcher->wr, watcher->num_readers, watcher->flags);
watcher->flags |= WATCHER_CLOSING;
OSAddAtomic(1, &watcher->num_readers);
unlock_watch_table();
while (watcher->num_readers > 1 && counter++ < 5000) {
lock_watch_table();
fsevents_wakeup(watcher); // in case they're asleep
unlock_watch_table();
tsleep(watcher, PRIBIO, "fsevents-close", 1);
}
if (counter++ >= 5000) {
// printf("fsevents: close: still have readers! (%d)\n", watcher->num_readers);
panic("fsevents: close: still have readers! (%d)", watcher->num_readers);
}
// drain the event_queue
lck_rw_lock_exclusive(&event_handling_lock);
while (watcher->rd != watcher->wr) {
kfse = watcher->event_queue[watcher->rd];
watcher->event_queue[watcher->rd] = NULL;
watcher->rd = (watcher->rd + 1) % watcher->eventq_size;
OSSynchronizeIO();
if (kfse != NULL && kfse->type != FSE_INVALID && kfse->refcount >= 1) {
release_event_ref(kfse);
}
}
lck_rw_unlock_exclusive(&event_handling_lock);
kfree_data(watcher->event_list, watcher->num_events * sizeof(int8_t));
kfree_data(watcher->devices_not_to_watch, watcher->num_devices * sizeof(dev_t));
kfree_type(fs_event_watcher, kfs_event *, watcher->eventq_size, watcher);
return;
}
unlock_watch_table();
}
#define EVENT_DELAY_IN_MS 10
static thread_call_t event_delivery_timer = NULL;
static int timer_set = 0;
static void
delayed_event_delivery(__unused void *param0, __unused void *param1)
{
int i;
lock_watch_table();
for (i = 0; i < MAX_WATCHERS; i++) {
if (watcher_table[i] != NULL && watcher_table[i]->rd != watcher_table[i]->wr) {
fsevents_wakeup(watcher_table[i]);
}
}
timer_set = 0;
unlock_watch_table();
}
//
// The watch table must be locked before calling this function.
//
static void
schedule_event_wakeup(void)
{
uint64_t deadline;
if (event_delivery_timer == NULL) {
event_delivery_timer = thread_call_allocate((thread_call_func_t)delayed_event_delivery, NULL);
}
clock_interval_to_deadline(EVENT_DELAY_IN_MS, 1000 * 1000, &deadline);
thread_call_enter_delayed(event_delivery_timer, deadline);
timer_set = 1;
}
#define MAX_NUM_PENDING 16
//
// NOTE: the watch table must be locked before calling
// this routine.
//
static int
watcher_add_event(fs_event_watcher *watcher, kfs_event *kfse)
{
if (kfse->abstime > watcher->max_event_id) {
watcher->max_event_id = kfse->abstime;
}
if (((watcher->wr + 1) % watcher->eventq_size) == watcher->rd) {
watcher->flags |= WATCHER_DROPPED_EVENTS;
fsevents_wakeup(watcher);
return ENOSPC;
}
OSAddAtomic(1, &kfse->refcount);
watcher->event_queue[watcher->wr] = kfse;
OSSynchronizeIO();
watcher->wr = (watcher->wr + 1) % watcher->eventq_size;
//
// wake up the watcher if there are more than MAX_NUM_PENDING events.
// otherwise schedule a timer (if one isn't already set) which will
// send any pending events if no more are received in the next
// EVENT_DELAY_IN_MS milli-seconds.
//
int32_t num_pending = 0;
if (watcher->rd < watcher->wr) {
num_pending = watcher->wr - watcher->rd;
}
if (watcher->rd > watcher->wr) {
num_pending = watcher->wr + watcher->eventq_size - watcher->rd;
}
if (num_pending > (watcher->eventq_size * 3 / 4) && !(watcher->flags & WATCHER_APPLE_SYSTEM_SERVICE)) {
/* Non-Apple Service is falling behind, start dropping events for this process */
lck_rw_lock_exclusive(&event_handling_lock);
while (watcher->rd != watcher->wr) {
kfse = watcher->event_queue[watcher->rd];
watcher->event_queue[watcher->rd] = NULL;
watcher->rd = (watcher->rd + 1) % watcher->eventq_size;
OSSynchronizeIO();
if (kfse != NULL && kfse->type != FSE_INVALID && kfse->refcount >= 1) {
release_event_ref(kfse);
}
}
watcher->flags |= WATCHER_DROPPED_EVENTS;
lck_rw_unlock_exclusive(&event_handling_lock);
printf("fsevents: watcher falling behind: %s (pid: %d) rd: %4d wr: %4d q_size: %4d flags: 0x%x\n",
watcher->proc_name, watcher->pid, watcher->rd, watcher->wr,
watcher->eventq_size, watcher->flags);
fsevents_wakeup(watcher);
} else if (num_pending > MAX_NUM_PENDING) {
fsevents_wakeup(watcher);
} else if (timer_set == 0) {
schedule_event_wakeup();
}
return 0;
}
static int
fill_buff(uint16_t type, int32_t size, const void *data,
char *buff, int32_t *_buff_idx, int32_t buff_sz,
struct uio *uio)
{
int32_t amt, error = 0, buff_idx = *_buff_idx;
uint16_t tmp;
//
// the +1 on the size is to guarantee that the main data
// copy loop will always copy at least 1 byte
//
if ((buff_sz - buff_idx) <= (int)(2 * sizeof(uint16_t) + 1)) {
if (buff_idx > uio_resid(uio)) {
error = ENOSPC;
goto get_out;
}
error = uiomove(buff, buff_idx, uio);
if (error) {
goto get_out;
}
buff_idx = 0;
}
// copy out the header (type & size)
memcpy(&buff[buff_idx], &type, sizeof(uint16_t));
buff_idx += sizeof(uint16_t);
tmp = size & 0xffff;
memcpy(&buff[buff_idx], &tmp, sizeof(uint16_t));
buff_idx += sizeof(uint16_t);
// now copy the body of the data, flushing along the way
// if the buffer fills up.
//
while (size > 0) {
amt = (size < (buff_sz - buff_idx)) ? size : (buff_sz - buff_idx);
memcpy(&buff[buff_idx], data, amt);
size -= amt;
buff_idx += amt;
data = (const char *)data + amt;
if (size > (buff_sz - buff_idx)) {
if (buff_idx > uio_resid(uio)) {
error = ENOSPC;
goto get_out;
}
error = uiomove(buff, buff_idx, uio);
if (error) {
goto get_out;
}
buff_idx = 0;
}
if (amt == 0) { // just in case...
break;
}
}
get_out:
*_buff_idx = buff_idx;
return error;
}
static int copy_out_kfse(fs_event_watcher *watcher, kfs_event *kfse, struct uio *uio) __attribute__((noinline));
static int
copy_out_kfse(fs_event_watcher *watcher, kfs_event *kfse, struct uio *uio)
{
int error;
uint16_t tmp16;
int32_t type;
kfs_event *cur;
char evbuff[512];
int evbuff_idx = 0;
if (kfse->type == FSE_INVALID) {
panic("fsevents: copy_out_kfse: asked to copy out an invalid event (kfse %p, refcount %d)", kfse, kfse->refcount);
}
if (kfse->flags & KFSE_BEING_CREATED) {
return 0;
}
if (((kfse->type == FSE_RENAME) || (kfse->type == FSE_CLONE)) &&
kfse->regular_event.dest == NULL) {
//
// This can happen if an event gets recycled but we had a
// pointer to it in our event queue. The event is the
// destination of a rename or clone which we'll process
// separately (that is, another kfse points to this one
// so it's ok to skip this guy because we'll process it
// when we process the other one)
error = 0;
goto get_out;
}
if (watcher->flags & WATCHER_WANTS_EXTENDED_INFO) {
type = (kfse->type & 0xfff);
if (kfse->flags & KFSE_CONTAINS_DROPPED_EVENTS) {
type |= (FSE_CONTAINS_DROPPED_EVENTS << FSE_FLAG_SHIFT);
} else if (kfse->flags & KFSE_COMBINED_EVENTS) {
type |= (FSE_COMBINED_EVENTS << FSE_FLAG_SHIFT);
}
} else {
type = (int32_t)kfse->type;
}
// copy out the type of the event
memcpy(evbuff, &type, sizeof(int32_t));
evbuff_idx += sizeof(int32_t);
// copy out the pid of the person that generated the event
memcpy(&evbuff[evbuff_idx], &kfse->pid, sizeof(pid_t));
evbuff_idx += sizeof(pid_t);
cur = kfse;
copy_again:
if (kfse->type == FSE_DOCID_CHANGED ||
kfse->type == FSE_DOCID_CREATED) {
dev_t dev = cur->docid_event.dev;
ino64_t src_ino = cur->docid_event.src_ino;
ino64_t dst_ino = cur->docid_event.dst_ino;
uint64_t docid = cur->docid_event.docid;
error = fill_buff(FSE_ARG_DEV, sizeof(dev_t), &dev, evbuff,
&evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INO, sizeof(ino64_t), &src_ino,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INO, sizeof(ino64_t), &dst_ino,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INT64, sizeof(uint64_t), &docid,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
goto done;
}
if (kfse->type == FSE_UNMOUNT_PENDING) {
dev_t dev = cur->regular_event.dev;
error = fill_buff(FSE_ARG_DEV, sizeof(dev_t), &dev,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
goto done;
}
if (kfse->type == FSE_ACTIVITY) {
error = fill_buff(FSE_ARG_INT32, sizeof(cur->activity_event.version), &cur->activity_event.version,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_DEV, sizeof(cur->activity_event.dev), &cur->activity_event.dev, evbuff,
&evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INO, sizeof(cur->activity_event.ino), &cur->activity_event.ino,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INT64, sizeof(cur->activity_event.origin_id), &cur->activity_event.origin_id,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INT64, sizeof(cur->activity_event.age), &cur->activity_event.age,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INT32, sizeof(cur->activity_event.use_state), &cur->activity_event.use_state,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INT32, sizeof(cur->activity_event.urgency), &cur->activity_event.urgency,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INT64, sizeof(cur->activity_event.size), &cur->activity_event.size,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
goto done;
}
#if CONFIG_FSE_ACCESS_GRANTED
if (kfse->type == FSE_ACCESS_GRANTED) {
//
// KFSE_CONTAINS_DROPPED_EVENTS will be set if either
// the path or audit token are bogus; don't copy out
// either in that case.
//
if (cur->flags & KFSE_CONTAINS_DROPPED_EVENTS) {
goto done;
}
error = fill_buff(FSE_ARG_STRING,
cur->access_granted_event.len,
cur->access_granted_event.str,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_AUDIT_TOKEN,
sizeof(cur->access_granted_event.audit_token),
&cur->access_granted_event.audit_token,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
goto done;
}
#endif
if (cur->regular_event.str == NULL ||
cur->regular_event.str[0] == '\0') {
printf("copy_out_kfse:2: empty/short path (%s)\n",
cur->regular_event.str);
error = fill_buff(FSE_ARG_STRING, 2, "/", evbuff, &evbuff_idx,
sizeof(evbuff), uio);
} else {
error = fill_buff(FSE_ARG_STRING, cur->regular_event.len,
cur->regular_event.str, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
}
if (error != 0) {
goto get_out;
}
if (cur->regular_event.dev == 0 && cur->regular_event.ino == 0) {
// this happens when a rename event happens and the
// destination of the rename did not previously exist.
// it thus has no other file info so skip copying out
// the stuff below since it isn't initialized
goto done;
}
if (watcher->flags & WATCHER_WANTS_COMPACT_EVENTS) {
// We rely on the layout of the "regular_event"
// structure being the same as fse_info in order
// to speed up this copy. The nlink field in
// fse_info is not included.
error = fill_buff(FSE_ARG_FINFO, KFSE_INFO_COPYSIZE,
&cur->regular_event, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
} else {
error = fill_buff(FSE_ARG_DEV, sizeof(dev_t),
&cur->regular_event.dev, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_INO, sizeof(ino64_t),
&cur->regular_event.ino, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_MODE, sizeof(int32_t),
&cur->regular_event.mode, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_UID, sizeof(uid_t),
&cur->regular_event.uid, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
error = fill_buff(FSE_ARG_GID, sizeof(gid_t),
&cur->regular_event.document_id, evbuff, &evbuff_idx,
sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
}
if (cur->regular_event.dest) {
cur = cur->regular_event.dest;
goto copy_again;
}
done:
// very last thing: the time stamp
error = fill_buff(FSE_ARG_INT64, sizeof(uint64_t), &cur->abstime,
evbuff, &evbuff_idx, sizeof(evbuff), uio);
if (error != 0) {
goto get_out;
}
// check if the FSE_ARG_DONE will fit
if (sizeof(uint16_t) > sizeof(evbuff) - evbuff_idx) {
if (evbuff_idx > uio_resid(uio)) {
error = ENOSPC;
goto get_out;
}
error = uiomove(evbuff, evbuff_idx, uio);
if (error) {
goto get_out;
}
evbuff_idx = 0;
}
tmp16 = FSE_ARG_DONE;
memcpy(&evbuff[evbuff_idx], &tmp16, sizeof(uint16_t));
evbuff_idx += sizeof(uint16_t);
// flush any remaining data in the buffer (and hopefully
// in most cases this is the only uiomove we'll do)
if (evbuff_idx > uio_resid(uio)) {
error = ENOSPC;
} else {
error = uiomove(evbuff, evbuff_idx, uio);
}
get_out:
return error;
}
static int
fmod_watch(fs_event_watcher *watcher, struct uio *uio)
{
int error = 0;
user_ssize_t last_full_event_resid;
kfs_event *kfse;
uint16_t tmp16;
int skipped;
last_full_event_resid = uio_resid(uio);
// need at least 2048 bytes of space (maxpathlen + 1 event buf)
if (uio_resid(uio) < 2048 || watcher == NULL) {
return EINVAL;
}
if (watcher->flags & WATCHER_CLOSING) {
return 0;
}
if (OSAddAtomic(1, &watcher->num_readers) != 0) {
// don't allow multiple threads to read from the fd at the same time
OSAddAtomic(-1, &watcher->num_readers);
return EAGAIN;
}
restart_watch:
if (watcher->rd == watcher->wr) {
if (watcher->flags & WATCHER_CLOSING) {
OSAddAtomic(-1, &watcher->num_readers);
return 0;
}
OSAddAtomic(1, &watcher->blockers);
// there's nothing to do, go to sleep
error = tsleep((caddr_t)watcher, PUSER | PCATCH, "fsevents_empty", 0);
OSAddAtomic(-1, &watcher->blockers);
if (error != 0 || (watcher->flags & WATCHER_CLOSING)) {
OSAddAtomic(-1, &watcher->num_readers);
return error;
}
}
// if we dropped events, return that as an event first
if (watcher->flags & WATCHER_DROPPED_EVENTS) {
int32_t val = FSE_EVENTS_DROPPED;
error = uiomove((caddr_t)&val, sizeof(int32_t), uio);
if (error == 0) {
val = 0; // a fake pid
error = uiomove((caddr_t)&val, sizeof(int32_t), uio);
tmp16 = FSE_ARG_DONE; // makes it a consistent msg
error = uiomove((caddr_t)&tmp16, sizeof(int16_t), uio);
last_full_event_resid = uio_resid(uio);
}
if (error) {
OSAddAtomic(-1, &watcher->num_readers);
return error;
}
watcher->flags &= ~WATCHER_DROPPED_EVENTS;
}
skipped = 0;
lck_rw_lock_shared(&event_handling_lock);
while (uio_resid(uio) > 0 && watcher->rd != watcher->wr) {
if (watcher->flags & WATCHER_CLOSING) {
break;
}
//
// check if the event is something of interest to us
// (since it may have been recycled/reused and changed
// its type or which device it is for)
//
kfse = watcher->event_queue[watcher->rd];
if (!kfse || kfse->type == FSE_INVALID || kfse->type >= watcher->num_events || kfse->refcount < 1) {
break;
}
if (watcher->event_list[kfse->type] == FSE_REPORT) {
if (!(watcher->flags & WATCHER_APPLE_SYSTEM_SERVICE) &&
kfse->type != FSE_DOCID_CREATED &&
kfse->type != FSE_DOCID_CHANGED &&
kfse->type != FSE_ACTIVITY &&
is_ignored_directory(kfse->regular_event.str)) {
// If this is not an Apple System Service, skip specified directories
// radar://12034844
error = 0;
skipped = 1;
} else {
skipped = 0;
if (last_event_ptr == kfse) {
last_event_ptr = NULL;
last_event_type = -1;
last_coalesced_time = 0;
}
error = copy_out_kfse(watcher, kfse, uio);
if (error != 0) {
// if an event won't fit or encountered an error while
// we were copying it out, then backup to the last full
// event and just bail out. if the error was ENOENT
// then we can continue regular processing, otherwise
// we should unlock things and return.
uio_setresid(uio, last_full_event_resid);
if (error != ENOENT) {
lck_rw_unlock_shared(&event_handling_lock);
error = 0;
goto get_out;
}
}
last_full_event_resid = uio_resid(uio);
}
}
watcher->event_queue[watcher->rd] = NULL;
watcher->rd = (watcher->rd + 1) % watcher->eventq_size;
OSSynchronizeIO();
release_event_ref(kfse);
}
lck_rw_unlock_shared(&event_handling_lock);
if (skipped && error == 0) {
goto restart_watch;
}
get_out:
OSAddAtomic(-1, &watcher->num_readers);
return error;
}
//
// Shoo watchers away from a volume that's about to be unmounted
// (so that it can be cleanly unmounted).
//
void
fsevent_unmount(__unused struct mount *mp, __unused vfs_context_t ctx)
{
#if !defined(XNU_TARGET_OS_OSX)
dev_t dev = mp->mnt_vfsstat.f_fsid.val[0];
int error, waitcount = 0;
struct timespec ts = {.tv_sec = 1, .tv_nsec = 0};
// wait for any other pending unmounts to complete
lock_watch_table();
while (fsevent_unmount_dev != 0) {
error = msleep((caddr_t)&fsevent_unmount_dev, &watch_table_lock, PRIBIO, "fsevent_unmount_wait", &ts);
if (error == EWOULDBLOCK) {
error = 0;
}
if (!error && (++waitcount >= 10)) {
error = EWOULDBLOCK;
printf("timeout waiting to signal unmount pending for dev %d (fsevent_unmount_dev %d)\n", dev, fsevent_unmount_dev);
}
if (error) {
// there's a problem, bail out
unlock_watch_table();
return;
}
}
if (fs_event_type_watchers[FSE_UNMOUNT_PENDING] == 0) {
// nobody watching for unmount pending events
unlock_watch_table();
return;
}
// this is now the current unmount pending
fsevent_unmount_dev = dev;
fsevent_unmount_ack_count = fs_event_type_watchers[FSE_UNMOUNT_PENDING];
unlock_watch_table();
// send an event to notify the watcher they need to get off the mount
error = add_fsevent(FSE_UNMOUNT_PENDING, ctx, FSE_ARG_DEV, dev, FSE_ARG_DONE);
// wait for acknowledgment(s) (give up if it takes too long)
lock_watch_table();
waitcount = 0;
while (fsevent_unmount_dev == dev) {
error = msleep((caddr_t)&fsevent_unmount_dev, &watch_table_lock, PRIBIO, "fsevent_unmount_pending", &ts);
if (error == EWOULDBLOCK) {
error = 0;
}
if (!error && (++waitcount >= 10)) {
error = EWOULDBLOCK;
printf("unmount pending ack timeout for dev %d\n", dev);
}
if (error) {
// there's a problem, bail out
if (fsevent_unmount_dev == dev) {
fsevent_unmount_dev = 0;
fsevent_unmount_ack_count = 0;
}
wakeup((caddr_t)&fsevent_unmount_dev);
break;
}
}
unlock_watch_table();
#endif /* ! XNU_TARGET_OS_OSX */
}
//
// /dev/fsevents device code
//
static int fsevents_installed = 0;
typedef struct fsevent_handle {
UInt32 flags;
SInt32 active;
fs_event_watcher *watcher;
struct klist knotes;
struct selinfo si;
} fsevent_handle;
#define FSEH_CLOSING 0x0001
static int
fseventsf_read(struct fileproc *fp, struct uio *uio,
__unused int flags, __unused vfs_context_t ctx)
{
fsevent_handle *fseh = (struct fsevent_handle *)fp_get_data(fp);
int error;
error = fmod_watch(fseh->watcher, uio);
return error;
}
#pragma pack(push, 4)
typedef struct fsevent_dev_filter_args32 {
uint32_t num_devices;
user32_addr_t devices;
} fsevent_dev_filter_args32;
typedef struct fsevent_dev_filter_args64 {
uint32_t num_devices;
user64_addr_t devices;
} fsevent_dev_filter_args64;
#pragma pack(pop)
#define FSEVENTS_DEVICE_FILTER_32 _IOW('s', 100, fsevent_dev_filter_args32)
#define FSEVENTS_DEVICE_FILTER_64 _IOW('s', 100, fsevent_dev_filter_args64)
static int
fseventsf_ioctl(struct fileproc *fp, u_long cmd, caddr_t data, vfs_context_t ctx)
{
fsevent_handle *fseh = (struct fsevent_handle *)fp_get_data(fp);
int ret = 0;
fsevent_dev_filter_args64 *devfilt_args, _devfilt_args;
OSAddAtomic(1, &fseh->active);
if (fseh->flags & FSEH_CLOSING) {
OSAddAtomic(-1, &fseh->active);
return 0;
}
switch (cmd) {
case FIONBIO:
case FIOASYNC:
break;
case FSEVENTS_WANT_COMPACT_EVENTS: {
fseh->watcher->flags |= WATCHER_WANTS_COMPACT_EVENTS;
break;
}
case FSEVENTS_WANT_EXTENDED_INFO: {
fseh->watcher->flags |= WATCHER_WANTS_EXTENDED_INFO;
break;
}
case FSEVENTS_GET_CURRENT_ID: {
*(uint64_t *)data = fseh->watcher->max_event_id;
ret = 0;
break;
}
case FSEVENTS_DEVICE_FILTER_32: {
if (proc_is64bit(vfs_context_proc(ctx))) {
ret = EINVAL;
break;
}
fsevent_dev_filter_args32 *devfilt_args32 = (fsevent_dev_filter_args32 *)data;
devfilt_args = &_devfilt_args;
memset(devfilt_args, 0, sizeof(fsevent_dev_filter_args64));
devfilt_args->num_devices = devfilt_args32->num_devices;
devfilt_args->devices = CAST_USER_ADDR_T(devfilt_args32->devices);
goto handle_dev_filter;
}
case FSEVENTS_DEVICE_FILTER_64:
if (!proc_is64bit(vfs_context_proc(ctx))) {
ret = EINVAL;
break;
}
devfilt_args = (fsevent_dev_filter_args64 *)data;
handle_dev_filter:
{
int new_num_devices, old_num_devices = 0;
dev_t *devices_not_to_watch, *tmp = NULL;
if (devfilt_args->num_devices > 256) {
ret = EINVAL;
break;
}
new_num_devices = devfilt_args->num_devices;
if (new_num_devices == 0) {
lock_watch_table();
tmp = fseh->watcher->devices_not_to_watch;
fseh->watcher->devices_not_to_watch = NULL;
old_num_devices = fseh->watcher->num_devices;
fseh->watcher->num_devices = new_num_devices;
unlock_watch_table();
kfree_data(tmp, old_num_devices * sizeof(dev_t));
break;
}
devices_not_to_watch = kalloc_data(new_num_devices * sizeof(dev_t), Z_WAITOK);
if (devices_not_to_watch == NULL) {
ret = ENOMEM;
break;
}
ret = copyin((user_addr_t)devfilt_args->devices,
(void *)devices_not_to_watch,
new_num_devices * sizeof(dev_t));
if (ret) {
kfree_data(devices_not_to_watch, new_num_devices * sizeof(dev_t));
break;
}
lock_watch_table();
old_num_devices = fseh->watcher->num_devices;
fseh->watcher->num_devices = new_num_devices;
tmp = fseh->watcher->devices_not_to_watch;
fseh->watcher->devices_not_to_watch = devices_not_to_watch;
unlock_watch_table();
kfree_data(tmp, old_num_devices * sizeof(dev_t));
break;
}
case FSEVENTS_UNMOUNT_PENDING_ACK: {
lock_watch_table();
dev_t dev = *(dev_t *)data;
if (fsevent_unmount_dev == dev) {
if (--fsevent_unmount_ack_count <= 0) {
fsevent_unmount_dev = 0;
wakeup((caddr_t)&fsevent_unmount_dev);
}
} else {
printf("unexpected unmount pending ack %d (%d)\n", dev, fsevent_unmount_dev);
ret = EINVAL;
}
unlock_watch_table();
break;
}
default:
ret = EINVAL;
break;
}
OSAddAtomic(-1, &fseh->active);
return ret;
}
static int
fseventsf_select(struct fileproc *fp, int which, __unused void *wql, vfs_context_t ctx)
{
fsevent_handle *fseh = (struct fsevent_handle *)fp_get_data(fp);
int ready = 0;
if ((which != FREAD) || (fseh->watcher->flags & WATCHER_CLOSING)) {
return 0;
}
// if there's nothing in the queue, we're not ready
if (fseh->watcher->rd != fseh->watcher->wr) {
ready = 1;
}
if (!ready) {
lock_watch_table();
selrecord(vfs_context_proc(ctx), &fseh->si, wql);
unlock_watch_table();
}
return ready;
}
#if NOTUSED
static int
fseventsf_stat(__unused struct fileproc *fp, __unused struct stat *sb, __unused vfs_context_t ctx)
{
return ENOTSUP;
}
#endif
static int
fseventsf_close(struct fileglob *fg, __unused vfs_context_t ctx)
{
fsevent_handle *fseh = (struct fsevent_handle *)fg_get_data(fg);
fs_event_watcher *watcher;
OSBitOrAtomic(FSEH_CLOSING, &fseh->flags);
while (OSAddAtomic(0, &fseh->active) > 0) {
tsleep((caddr_t)fseh->watcher, PRIBIO, "fsevents-close", 1);
}
watcher = fseh->watcher;
fg_set_data(fg, NULL);
fseh->watcher = NULL;
remove_watcher(watcher);
selthreadclear(&fseh->si);
kfree_type(fsevent_handle, fseh);
return 0;
}
static void
filt_fsevent_detach(struct knote *kn)
{
fsevent_handle *fseh = (struct fsevent_handle *)knote_kn_hook_get_raw(kn);
lock_watch_table();
KNOTE_DETACH(&fseh->knotes, kn);
unlock_watch_table();
}
/*
* Determine whether this knote should be active
*
* This is kind of subtle.
* --First, notice if the vnode has been revoked: in so, override hint
* --EVFILT_READ knotes are checked no matter what the hint is
* --Other knotes activate based on hint.
* --If hint is revoke, set special flags and activate
*/
static int
filt_fsevent_common(struct knote *kn, struct kevent_qos_s *kev, long hint)
{
fsevent_handle *fseh = (struct fsevent_handle *)knote_kn_hook_get_raw(kn);
int activate = 0;
int32_t rd, wr, amt;
int64_t data = 0;
if (NOTE_REVOKE == hint) {
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
activate = 1;
}
rd = fseh->watcher->rd;
wr = fseh->watcher->wr;
if (rd <= wr) {
amt = wr - rd;
} else {
amt = fseh->watcher->eventq_size - (rd - wr);
}
switch (kn->kn_filter) {
case EVFILT_READ:
data = amt;
activate = (data != 0);
break;
case EVFILT_VNODE:
/* Check events this note matches against the hint */
if (kn->kn_sfflags & hint) {
kn->kn_fflags |= (uint32_t)hint; /* Set which event occurred */
}
if (kn->kn_fflags != 0) {
activate = 1;
}
break;
default:
// nothing to do...
break;
}
if (activate && kev) {
knote_fill_kevent(kn, kev, data);
}
return activate;
}
static int
filt_fsevent(struct knote *kn, long hint)
{
return filt_fsevent_common(kn, NULL, hint);
}
static int
filt_fsevent_touch(struct knote *kn, struct kevent_qos_s *kev)
{
int res;
lock_watch_table();
/* accept new fflags/data as saved */
kn->kn_sfflags = kev->fflags;
kn->kn_sdata = kev->data;
/* restrict the current results to the (smaller?) set of new interest */
/*
* For compatibility with previous implementations, we leave kn_fflags
* as they were before.
*/
//kn->kn_fflags &= kev->fflags;
/* determine if the filter is now fired */
res = filt_fsevent_common(kn, NULL, 0);
unlock_watch_table();
return res;
}
static int
filt_fsevent_process(struct knote *kn, struct kevent_qos_s *kev)
{
int res;
lock_watch_table();
res = filt_fsevent_common(kn, kev, 0);
unlock_watch_table();
return res;
}
SECURITY_READ_ONLY_EARLY(struct filterops) fsevent_filtops = {
.f_isfd = 1,
.f_attach = NULL,
.f_detach = filt_fsevent_detach,
.f_event = filt_fsevent,
.f_touch = filt_fsevent_touch,
.f_process = filt_fsevent_process,
};
static int
fseventsf_kqfilter(struct fileproc *fp, struct knote *kn,
__unused struct kevent_qos_s *kev)
{
fsevent_handle *fseh = (struct fsevent_handle *)fp_get_data(fp);
int res;
kn->kn_filtid = EVFILTID_FSEVENT;
knote_kn_hook_set_raw(kn, (void *) fseh);
lock_watch_table();
KNOTE_ATTACH(&fseh->knotes, kn);
/* check to see if it is fired already */
res = filt_fsevent_common(kn, NULL, 0);
unlock_watch_table();
return res;
}
static int
fseventsf_drain(struct fileproc *fp, __unused vfs_context_t ctx)
{
int counter = 0;
fsevent_handle *fseh = (struct fsevent_handle *)fp_get_data(fp);
// if there are people still waiting, sleep for 10ms to
// let them clean up and get out of there. however we
// also don't want to get stuck forever so if they don't
// exit after 5 seconds we're tearing things down anyway.
while (fseh->watcher->blockers && counter++ < 500) {
// issue wakeup in case anyone is blocked waiting for an event
// do this each time we wakeup in case the blocker missed
// the wakeup due to the unprotected test of WATCHER_CLOSING
// and decision to tsleep in fmod_watch... this bit of
// latency is a decent tradeoff against not having to
// take and drop a lock in fmod_watch
lock_watch_table();
fsevents_wakeup(fseh->watcher);
unlock_watch_table();
tsleep((caddr_t)fseh->watcher, PRIBIO, "watcher-close", 1);
}
return 0;
}
static int
fseventsopen(__unused dev_t dev, __unused int flag, __unused int mode, __unused struct proc *p)
{
if (!kauth_cred_issuser(kauth_cred_get())) {
return EPERM;
}
return 0;
}
static int
fseventsclose(__unused dev_t dev, __unused int flag, __unused int mode, __unused struct proc *p)
{
return 0;
}
static int
fseventsread(__unused dev_t dev, __unused struct uio *uio, __unused int ioflag)
{
return EIO;
}
static int
parse_buffer_and_add_events(const char *buffer, size_t bufsize, vfs_context_t ctx, size_t *remainder)
{
const fse_info *finfo, *dest_finfo;
const char *path, *ptr, *dest_path, *event_start = buffer;
size_t path_len, dest_path_len;
int type, err = 0;
ptr = buffer;
while ((ptr + sizeof(int) + sizeof(fse_info) + 1) < buffer + bufsize) {
type = *(const int *)ptr;
if (type < 0 || type == FSE_ACCESS_GRANTED || type == FSE_ACTIVITY ||
type >= FSE_MAX_EVENTS) {
err = EINVAL;
break;
}
ptr += sizeof(int);
finfo = (const fse_info *)ptr;
ptr += sizeof(fse_info);
path = ptr;
while (ptr < buffer + bufsize && *ptr != '\0') {
ptr++;
}
if (ptr >= buffer + bufsize) {
break;
}
ptr++; // advance over the trailing '\0'
path_len = ptr - path;
if (type != FSE_RENAME && type != FSE_EXCHANGE && type != FSE_CLONE) {
event_start = ptr; // record where the next event starts
err = add_fsevent(type, ctx, FSE_ARG_STRING, path_len, path, FSE_ARG_FINFO, finfo, FSE_ARG_DONE);
if (err) {
break;
}
continue;
}
//
// if we're here we have to slurp up the destination finfo
// and path so that we can pass them to the add_fsevent()
// call. basically it's a copy of the above code.
//
dest_finfo = (const fse_info *)ptr;
ptr += sizeof(fse_info);
dest_path = ptr;
while (ptr < buffer + bufsize && *ptr != '\0') {
ptr++;
}
if (ptr >= buffer + bufsize) {
break;
}
ptr++; // advance over the trailing '\0'
event_start = ptr; // record where the next event starts
dest_path_len = ptr - dest_path;
//
// If the destination inode number is non-zero, generate a rename
// with both source and destination FSE_ARG_FINFO. Otherwise generate
// a rename with only one FSE_ARG_FINFO. If you need to inject an
// exchange with an inode of zero, just make that inode (and its path)
// come in as the first one, not the second.
//
if (dest_finfo->ino) {
err = add_fsevent(type, ctx,
FSE_ARG_STRING, path_len, path, FSE_ARG_FINFO, finfo,
FSE_ARG_STRING, dest_path_len, dest_path, FSE_ARG_FINFO, dest_finfo,
FSE_ARG_DONE);
} else {
err = add_fsevent(type, ctx,
FSE_ARG_STRING, path_len, path, FSE_ARG_FINFO, finfo,
FSE_ARG_STRING, dest_path_len, dest_path,
FSE_ARG_DONE);
}
if (err) {
break;
}
}
// if the last event wasn't complete, set the remainder
// to be the last event start boundary.
//
*remainder = (long)((buffer + bufsize) - event_start);
return err;
}
//
// Note: this buffer size can not ever be less than
// 2*MAXPATHLEN + 2*sizeof(fse_info) + sizeof(int)
// because that is the max size for a single event.
// I made it 4k to be a "nice" size. making it
// smaller is not a good idea.
//
#define WRITE_BUFFER_SIZE 4096
static char *write_buffer = NULL;
static int
fseventswrite(__unused dev_t dev, struct uio *uio, __unused int ioflag)
{
int error = 0;
size_t count, offset = 0, remainder = 0;
vfs_context_t ctx = vfs_context_current();
lck_mtx_lock(&event_writer_lock);
if (write_buffer == NULL) {
write_buffer = zalloc_permanent(WRITE_BUFFER_SIZE, ZALIGN_64);
}
//
// this loop copies in and processes the events written.
// it takes care to copy in reasonable size chunks and
// process them. if there is an event that spans a chunk
// boundary we're careful to copy those bytes down to the
// beginning of the buffer and read the next chunk in just
// after it.
//
while (uio_resid(uio)) {
count = MIN(WRITE_BUFFER_SIZE - offset, (size_t)uio_resid(uio));
error = uiomove(write_buffer + offset, (int)count, uio);
if (error) {
break;
}
error = parse_buffer_and_add_events(write_buffer, offset + count, ctx, &remainder);
if (error) {
break;
}
//
// if there's any remainder, copy it down to the beginning
// of the buffer so that it will get processed the next time
// through the loop. note that the remainder always starts
// at an event boundary.
//
memmove(write_buffer, (write_buffer + count + offset) - remainder, remainder);
offset = remainder;
}
lck_mtx_unlock(&event_writer_lock);
return error;
}
static const struct fileops fsevents_fops = {
.fo_type = DTYPE_FSEVENTS,
.fo_read = fseventsf_read,
.fo_write = fo_no_write,
.fo_ioctl = fseventsf_ioctl,
.fo_select = fseventsf_select,
.fo_close = fseventsf_close,
.fo_kqfilter = fseventsf_kqfilter,
.fo_drain = fseventsf_drain,
};
typedef struct fsevent_clone_args32 {
user32_addr_t event_list;
int32_t num_events;
int32_t event_queue_depth;
user32_addr_t fd;
} fsevent_clone_args32;
typedef struct fsevent_clone_args64 {
user64_addr_t event_list;
int32_t num_events;
int32_t event_queue_depth;
user64_addr_t fd;
} fsevent_clone_args64;
#define FSEVENTS_CLONE_32 _IOW('s', 1, fsevent_clone_args32)
#define FSEVENTS_CLONE_64 _IOW('s', 1, fsevent_clone_args64)
static int
fseventsioctl(__unused dev_t dev, u_long cmd, caddr_t data, __unused int flag, struct proc *p)
{
struct fileproc *f;
int fd, error;
fsevent_handle *fseh = NULL;
fsevent_clone_args64 *fse_clone_args, _fse_clone;
int8_t *event_list;
int is64bit = proc_is64bit(p);
switch (cmd) {
case FSEVENTS_CLONE_32: {
if (is64bit) {
return EINVAL;
}
fsevent_clone_args32 *args32 = (fsevent_clone_args32 *)data;
fse_clone_args = &_fse_clone;
memset(fse_clone_args, 0, sizeof(fsevent_clone_args64));
fse_clone_args->event_list = CAST_USER_ADDR_T(args32->event_list);
fse_clone_args->num_events = args32->num_events;
fse_clone_args->event_queue_depth = args32->event_queue_depth;
fse_clone_args->fd = CAST_USER_ADDR_T(args32->fd);
goto handle_clone;
}
case FSEVENTS_CLONE_64:
if (!is64bit) {
return EINVAL;
}
fse_clone_args = (fsevent_clone_args64 *)data;
handle_clone:
if (fse_clone_args->num_events <= 0 || fse_clone_args->num_events > 4096) {
return EINVAL;
}
fseh = kalloc_type(fsevent_handle, Z_WAITOK | Z_ZERO | Z_NOFAIL);
klist_init(&fseh->knotes);
event_list = kalloc_data(fse_clone_args->num_events * sizeof(int8_t), Z_WAITOK);
if (event_list == NULL) {
kfree_type(fsevent_handle, fseh);
return ENOMEM;
}
error = copyin((user_addr_t)fse_clone_args->event_list,
(void *)event_list,
fse_clone_args->num_events * sizeof(int8_t));
if (error) {
kfree_data(event_list, fse_clone_args->num_events * sizeof(int8_t));
kfree_type(fsevent_handle, fseh);
return error;
}
/*
* Lock down the user's "fd" result buffer so it's safe
* to hold locks while we copy it out.
*/
error = vslock((user_addr_t)fse_clone_args->fd,
sizeof(int32_t));
if (error) {
kfree_data(event_list, fse_clone_args->num_events * sizeof(int8_t));
kfree_type(fsevent_handle, fseh);
return error;
}
error = add_watcher(event_list,
fse_clone_args->num_events,
fse_clone_args->event_queue_depth,
&fseh->watcher,
fseh);
if (error) {
vsunlock((user_addr_t)fse_clone_args->fd,
sizeof(int32_t), 0);
kfree_data(event_list, fse_clone_args->num_events * sizeof(int8_t));
kfree_type(fsevent_handle, fseh);
return error;
}
fseh->watcher->fseh = fseh;
error = falloc(p, &f, &fd);
if (error) {
remove_watcher(fseh->watcher);
vsunlock((user_addr_t)fse_clone_args->fd,
sizeof(int32_t), 0);
kfree_data(event_list, fse_clone_args->num_events * sizeof(int8_t));
kfree_type(fsevent_handle, fseh);
return error;
}
proc_fdlock(p);
f->fp_glob->fg_flag = FREAD | FWRITE;
f->fp_glob->fg_ops = &fsevents_fops;
fp_set_data(f, fseh);
/*
* We can safely hold the proc_fdlock across this copyout()
* because of the vslock() call above. The vslock() call
* also ensures that we will never get an error, so assert
* this.
*/
error = copyout((void *)&fd, (user_addr_t)fse_clone_args->fd, sizeof(int32_t));
assert(error == 0);
procfdtbl_releasefd(p, fd, NULL);
fp_drop(p, fd, f, 1);
proc_fdunlock(p);
vsunlock((user_addr_t)fse_clone_args->fd,
sizeof(int32_t), 1);
break;
default:
error = EINVAL;
break;
}
return error;
}
static void
fsevents_wakeup(fs_event_watcher *watcher)
{
selwakeup(&watcher->fseh->si);
KNOTE(&watcher->fseh->knotes, NOTE_WRITE | NOTE_NONE);
wakeup((caddr_t)watcher);
}
/*
* A struct describing which functions will get invoked for certain
* actions.
*/
static const struct cdevsw fsevents_cdevsw =
{
.d_open = fseventsopen,
.d_close = fseventsclose,
.d_read = fseventsread,
.d_write = fseventswrite,
.d_ioctl = fseventsioctl,
.d_stop = eno_stop,
.d_reset = eno_reset,
.d_select = eno_select,
.d_mmap = eno_mmap,
.d_strategy = eno_strat,
.d_reserved_1 = eno_getc,
.d_reserved_2 = eno_putc,
};
/*
* Called to initialize our device,
* and to register ourselves with devfs
*/
void
fsevents_init(void)
{
int ret;
if (fsevents_installed) {
return;
}
fsevents_installed = 1;
ret = cdevsw_add(-1, &fsevents_cdevsw);
if (ret < 0) {
fsevents_installed = 0;
return;
}
devfs_make_node(makedev(ret, 0), DEVFS_CHAR,
UID_ROOT, GID_WHEEL, 0644, "fsevents");
fsevents_internal_init();
}
char *
get_pathbuff(void)
{
return zalloc(ZV_NAMEI);
}
void
release_pathbuff(char *path)
{
if (path == NULL) {
return;
}
zfree(ZV_NAMEI, path);
}
int
get_fse_info(struct vnode *vp, fse_info *fse, __unused vfs_context_t ctx)
{
struct vnode_attr va;
VATTR_INIT(&va);
VATTR_WANTED(&va, va_fsid);
va.va_vaflags |= VA_REALFSID;
VATTR_WANTED(&va, va_fileid);
VATTR_WANTED(&va, va_mode);
VATTR_WANTED(&va, va_uid);
VATTR_WANTED(&va, va_document_id);
if (vp->v_flag & VISHARDLINK) {
if (vp->v_type == VDIR) {
VATTR_WANTED(&va, va_dirlinkcount);
} else {
VATTR_WANTED(&va, va_nlink);
}
}
if (vnode_getattr(vp, &va, vfs_context_kernel()) != 0) {
memset(fse, 0, sizeof(fse_info));
return -1;
}
return vnode_get_fse_info_from_vap(vp, fse, &va);
}
int
vnode_get_fse_info_from_vap(vnode_t vp, fse_info *fse, struct vnode_attr *vap)
{
fse->ino = (ino64_t)vap->va_fileid;
fse->dev = (dev_t)vap->va_fsid;
fse->mode = (int32_t)vnode_vttoif(vnode_vtype(vp)) | vap->va_mode;
fse->uid = (uid_t)vap->va_uid;
fse->document_id = (uint32_t)vap->va_document_id;
if (vp->v_flag & VISHARDLINK) {
fse->mode |= FSE_MODE_HLINK;
if (vp->v_type == VDIR) {
fse->nlink = (uint64_t)vap->va_dirlinkcount;
} else {
fse->nlink = (uint64_t)vap->va_nlink;
}
}
return 0;
}
void
create_fsevent_from_kevent(vnode_t vp, uint32_t kevents, struct vnode_attr *vap)
{
int fsevent_type = FSE_CONTENT_MODIFIED, len; // the default is the most pessimistic
char pathbuf[MAXPATHLEN];
fse_info fse;
if (kevents & VNODE_EVENT_DELETE) {
fsevent_type = FSE_DELETE;
} else if (kevents & (VNODE_EVENT_EXTEND | VNODE_EVENT_WRITE)) {
fsevent_type = FSE_CONTENT_MODIFIED;
} else if (kevents & VNODE_EVENT_LINK) {
fsevent_type = FSE_CREATE_FILE;
} else if (kevents & VNODE_EVENT_RENAME) {
fsevent_type = FSE_CREATE_FILE; // XXXdbg - should use FSE_RENAME but we don't have the destination info;
} else if (kevents & (VNODE_EVENT_FILE_CREATED | VNODE_EVENT_FILE_REMOVED | VNODE_EVENT_DIR_CREATED | VNODE_EVENT_DIR_REMOVED)) {
fsevent_type = FSE_STAT_CHANGED; // XXXdbg - because vp is a dir and the thing created/removed lived inside it
} else { // a catch all for VNODE_EVENT_PERMS, VNODE_EVENT_ATTRIB and anything else
fsevent_type = FSE_STAT_CHANGED;
}
// printf("convert_kevent: kevents 0x%x fsevent type 0x%x (for %s)\n", kevents, fsevent_type, vp->v_name ? vp->v_name : "(no-name)");
fse.dev = vap->va_fsid;
fse.ino = vap->va_fileid;
fse.mode = vnode_vttoif(vnode_vtype(vp)) | (uint32_t)vap->va_mode;
if (vp->v_flag & VISHARDLINK) {
fse.mode |= FSE_MODE_HLINK;
if (vp->v_type == VDIR) {
fse.nlink = vap->va_dirlinkcount;
} else {
fse.nlink = vap->va_nlink;
}
}
if (vp->v_type == VDIR) {
fse.mode |= FSE_REMOTE_DIR_EVENT;
}
fse.uid = vap->va_uid;
fse.document_id = vap->va_document_id;
len = sizeof(pathbuf);
if (vn_getpath_no_firmlink(vp, pathbuf, &len) == 0) {
add_fsevent(fsevent_type, vfs_context_current(), FSE_ARG_STRING, len, pathbuf, FSE_ARG_FINFO, &fse, FSE_ARG_DONE);
}
return;
}
#else /* CONFIG_FSE */
#include <sys/fsevents.h>
/*
* The get_pathbuff and release_pathbuff routines are used in places not
* related to fsevents, and it's a handy abstraction, so define trivial
* versions that don't cache a pool of buffers. This way, we don't have
* to conditionalize the callers, and they still get the advantage of the
* pool of buffers if CONFIG_FSE is turned on.
*/
char *
get_pathbuff(void)
{
return zalloc(ZV_NAMEI);
}
void
release_pathbuff(char *path)
{
zfree(ZV_NAMEI, path);
}
int
add_fsevent(__unused int type, __unused vfs_context_t ctx, ...)
{
return 0;
}
int
need_fsevent(__unused int type, __unused vnode_t vp)
{
return 0;
}
#endif /* CONFIG_FSE */
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