summary refs log tree commit diff
path: root/synapse/push/push_rule_evaluator.py
blob: 3c5632cd9153bc6d7424601f7b831762ca63dc4a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
# Copyright 2015, 2016 OpenMarket Ltd
# Copyright 2017 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import logging
import re
from typing import (
    Any,
    Dict,
    List,
    Mapping,
    Optional,
    Pattern,
    Sequence,
    Set,
    Tuple,
    Union,
)

from matrix_common.regex import glob_to_regex, to_word_pattern

from synapse.events import EventBase
from synapse.types import UserID
from synapse.util.caches.lrucache import LruCache

logger = logging.getLogger(__name__)


GLOB_REGEX = re.compile(r"\\\[(\\\!|)(.*)\\\]")
IS_GLOB = re.compile(r"[\?\*\[\]]")
INEQUALITY_EXPR = re.compile("^([=<>]*)([0-9]*)$")


def _room_member_count(
    ev: EventBase, condition: Mapping[str, Any], room_member_count: int
) -> bool:
    return _test_ineq_condition(condition, room_member_count)


def _sender_notification_permission(
    ev: EventBase,
    condition: Mapping[str, Any],
    sender_power_level: int,
    power_levels: Dict[str, Union[int, Dict[str, int]]],
) -> bool:
    notif_level_key = condition.get("key")
    if notif_level_key is None:
        return False

    notif_levels = power_levels.get("notifications", {})
    assert isinstance(notif_levels, dict)
    room_notif_level = notif_levels.get(notif_level_key, 50)

    return sender_power_level >= room_notif_level


def _test_ineq_condition(condition: Mapping[str, Any], number: int) -> bool:
    if "is" not in condition:
        return False
    m = INEQUALITY_EXPR.match(condition["is"])
    if not m:
        return False
    ineq = m.group(1)
    rhs = m.group(2)
    if not rhs.isdigit():
        return False
    rhs_int = int(rhs)

    if ineq == "" or ineq == "==":
        return number == rhs_int
    elif ineq == "<":
        return number < rhs_int
    elif ineq == ">":
        return number > rhs_int
    elif ineq == ">=":
        return number >= rhs_int
    elif ineq == "<=":
        return number <= rhs_int
    else:
        return False


def tweaks_for_actions(actions: List[Union[str, Dict]]) -> Dict[str, Any]:
    """
    Converts a list of actions into a `tweaks` dict (which can then be passed to
        the push gateway).

    This function ignores all actions other than `set_tweak` actions, and treats
    absent `value`s as `True`, which agrees with the only spec-defined treatment
    of absent `value`s (namely, for `highlight` tweaks).

    Args:
        actions: list of actions
            e.g. [
                {"set_tweak": "a", "value": "AAA"},
                {"set_tweak": "b", "value": "BBB"},
                {"set_tweak": "highlight"},
                "notify"
            ]

    Returns:
        dictionary of tweaks for those actions
            e.g. {"a": "AAA", "b": "BBB", "highlight": True}
    """
    tweaks = {}
    for a in actions:
        if not isinstance(a, dict):
            continue
        if "set_tweak" in a:
            # value is allowed to be absent in which case the value assumed
            # should be True.
            tweaks[a["set_tweak"]] = a.get("value", True)
    return tweaks


class PushRuleEvaluatorForEvent:
    def __init__(
        self,
        event: EventBase,
        room_member_count: int,
        sender_power_level: int,
        power_levels: Dict[str, Union[int, Dict[str, int]]],
        relations: Dict[str, Set[Tuple[str, str]]],
        relations_match_enabled: bool,
    ):
        self._event = event
        self._room_member_count = room_member_count
        self._sender_power_level = sender_power_level
        self._power_levels = power_levels
        self._relations = relations
        self._relations_match_enabled = relations_match_enabled

        # Maps strings of e.g. 'content.body' -> event["content"]["body"]
        self._value_cache = _flatten_dict(event)

        # Maps cache keys to final values.
        self._condition_cache: Dict[str, bool] = {}

    def check_conditions(
        self, conditions: Sequence[Mapping], uid: str, display_name: Optional[str]
    ) -> bool:
        """
        Returns true if a user's conditions/user ID/display name match the event.

        Args:
            conditions: The user's conditions to match.
            uid: The user's MXID.
            display_name: The display name.

        Returns:
             True if all conditions match the event, False otherwise.
        """
        for cond in conditions:
            _cache_key = cond.get("_cache_key", None)
            if _cache_key:
                res = self._condition_cache.get(_cache_key, None)
                if res is False:
                    return False
                elif res is True:
                    continue

            res = self.matches(cond, uid, display_name)
            if _cache_key:
                self._condition_cache[_cache_key] = bool(res)

            if not res:
                return False

        return True

    def matches(
        self, condition: Mapping[str, Any], user_id: str, display_name: Optional[str]
    ) -> bool:
        """
        Returns true if a user's condition/user ID/display name match the event.

        Args:
            condition: The user's condition to match.
            uid: The user's MXID.
            display_name: The display name, or None if there is not one.

        Returns:
             True if the condition matches the event, False otherwise.
        """
        if condition["kind"] == "event_match":
            return self._event_match(condition, user_id)
        elif condition["kind"] == "contains_display_name":
            return self._contains_display_name(display_name)
        elif condition["kind"] == "room_member_count":
            return _room_member_count(self._event, condition, self._room_member_count)
        elif condition["kind"] == "sender_notification_permission":
            return _sender_notification_permission(
                self._event, condition, self._sender_power_level, self._power_levels
            )
        elif (
            condition["kind"] == "org.matrix.msc3772.relation_match"
            and self._relations_match_enabled
        ):
            return self._relation_match(condition, user_id)
        else:
            # XXX This looks incorrect -- we have reached an unknown condition
            #     kind and are unconditionally returning that it matches. Note
            #     that it seems possible to provide a condition to the /pushrules
            #     endpoint with an unknown kind, see _rule_tuple_from_request_object.
            return True

    def _event_match(self, condition: Mapping, user_id: str) -> bool:
        """
        Check an "event_match" push rule condition.

        Args:
            condition: The "event_match" push rule condition to match.
            user_id: The user's MXID.

        Returns:
             True if the condition matches the event, False otherwise.
        """
        pattern = condition.get("pattern", None)

        if not pattern:
            pattern_type = condition.get("pattern_type", None)
            if pattern_type == "user_id":
                pattern = user_id
            elif pattern_type == "user_localpart":
                pattern = UserID.from_string(user_id).localpart

        if not pattern:
            logger.warning("event_match condition with no pattern")
            return False

        # XXX: optimisation: cache our pattern regexps
        if condition["key"] == "content.body":
            body = self._event.content.get("body", None)
            if not body or not isinstance(body, str):
                return False

            return _glob_matches(pattern, body, word_boundary=True)
        else:
            haystack = self._value_cache.get(condition["key"], None)
            if haystack is None:
                return False

            return _glob_matches(pattern, haystack)

    def _contains_display_name(self, display_name: Optional[str]) -> bool:
        """
        Check an "event_match" push rule condition.

        Args:
            display_name: The display name, or None if there is not one.

        Returns:
             True if the display name is found in the event body, False otherwise.
        """
        if not display_name:
            return False

        body = self._event.content.get("body", None)
        if not body or not isinstance(body, str):
            return False

        # Similar to _glob_matches, but do not treat display_name as a glob.
        r = regex_cache.get((display_name, False, True), None)
        if not r:
            r1 = re.escape(display_name)
            r1 = to_word_pattern(r1)
            r = re.compile(r1, flags=re.IGNORECASE)
            regex_cache[(display_name, False, True)] = r

        return bool(r.search(body))

    def _relation_match(self, condition: Mapping, user_id: str) -> bool:
        """
        Check an "relation_match" push rule condition.

        Args:
            condition: The "event_match" push rule condition to match.
            user_id: The user's MXID.

        Returns:
             True if the condition matches the event, False otherwise.
        """
        rel_type = condition.get("rel_type")
        if not rel_type:
            logger.warning("relation_match condition missing rel_type")
            return False

        sender_pattern = condition.get("sender")
        if sender_pattern is None:
            sender_type = condition.get("sender_type")
            if sender_type == "user_id":
                sender_pattern = user_id
        type_pattern = condition.get("type")

        # If any other relations matches, return True.
        for sender, event_type in self._relations.get(rel_type, ()):
            if sender_pattern and not _glob_matches(sender_pattern, sender):
                continue
            if type_pattern and not _glob_matches(type_pattern, event_type):
                continue
            # All values must have matched.
            return True

        # No relations matched.
        return False


# Caches (string, is_glob, word_boundary) -> regex for push. See _glob_matches
regex_cache: LruCache[Tuple[str, bool, bool], Pattern] = LruCache(
    50000, "regex_push_cache"
)


def _glob_matches(glob: str, value: str, word_boundary: bool = False) -> bool:
    """Tests if value matches glob.

    Args:
        glob
        value: String to test against glob.
        word_boundary: Whether to match against word boundaries or entire
            string. Defaults to False.
    """

    try:
        r = regex_cache.get((glob, True, word_boundary), None)
        if not r:
            r = glob_to_regex(glob, word_boundary=word_boundary)
            regex_cache[(glob, True, word_boundary)] = r
        return bool(r.search(value))
    except re.error:
        logger.warning("Failed to parse glob to regex: %r", glob)
        return False


def _flatten_dict(
    d: Union[EventBase, Mapping[str, Any]],
    prefix: Optional[List[str]] = None,
    result: Optional[Dict[str, str]] = None,
) -> Dict[str, str]:
    if prefix is None:
        prefix = []
    if result is None:
        result = {}
    for key, value in d.items():
        if isinstance(value, str):
            result[".".join(prefix + [key])] = value.lower()
        elif isinstance(value, Mapping):
            _flatten_dict(value, prefix=(prefix + [key]), result=result)

    return result