diff options
Diffstat (limited to 'synapse/rest/media')
| -rw-r--r-- | synapse/rest/media/v1/oembed.py | 135 | ||||
| -rw-r--r-- | synapse/rest/media/v1/preview_url_resource.py | 147 |
2 files changed, 140 insertions, 142 deletions
diff --git a/synapse/rest/media/v1/oembed.py b/synapse/rest/media/v1/oembed.py new file mode 100644 index 0000000000..afe41823e4 --- /dev/null +++ b/synapse/rest/media/v1/oembed.py @@ -0,0 +1,135 @@ +# Copyright 2021 The Matrix.org Foundation C.I.C. +# +# 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 +from typing import TYPE_CHECKING, Optional + +import attr + +from synapse.http.client import SimpleHttpClient + +if TYPE_CHECKING: + from synapse.server import HomeServer + +logger = logging.getLogger(__name__) + + +@attr.s(slots=True, auto_attribs=True) +class OEmbedResult: + # Either HTML content or URL must be provided. + html: Optional[str] + url: Optional[str] + title: Optional[str] + # Number of seconds to cache the content. + cache_age: int + + +class OEmbedError(Exception): + """An error occurred processing the oEmbed object.""" + + +class OEmbedProvider: + """ + A helper for accessing oEmbed content. + + It can be used to check if a URL should be accessed via oEmbed and for + requesting/parsing oEmbed content. + """ + + def __init__(self, hs: "HomeServer", client: SimpleHttpClient): + self._oembed_patterns = {} + for oembed_endpoint in hs.config.oembed.oembed_patterns: + for pattern in oembed_endpoint.url_patterns: + self._oembed_patterns[pattern] = oembed_endpoint.api_endpoint + self._client = client + + def get_oembed_url(self, url: str) -> Optional[str]: + """ + Check whether the URL should be downloaded as oEmbed content instead. + + Args: + url: The URL to check. + + Returns: + A URL to use instead or None if the original URL should be used. + """ + for url_pattern, endpoint in self._oembed_patterns.items(): + if url_pattern.fullmatch(url): + return endpoint + + # No match. + return None + + async def get_oembed_content(self, endpoint: str, url: str) -> OEmbedResult: + """ + Request content from an oEmbed endpoint. + + Args: + endpoint: The oEmbed API endpoint. + url: The URL to pass to the API. + + Returns: + An object representing the metadata returned. + + Raises: + OEmbedError if fetching or parsing of the oEmbed information fails. + """ + try: + logger.debug("Trying to get oEmbed content for url '%s'", url) + result = await self._client.get_json( + endpoint, + # TODO Specify max height / width. + # Note that only the JSON format is supported. + args={"url": url}, + ) + + # Ensure there's a version of 1.0. + if result.get("version") != "1.0": + raise OEmbedError("Invalid version: %s" % (result.get("version"),)) + + oembed_type = result.get("type") + + # Ensure the cache age is None or an int. + cache_age = result.get("cache_age") + if cache_age: + cache_age = int(cache_age) + + oembed_result = OEmbedResult(None, None, result.get("title"), cache_age) + + # HTML content. + if oembed_type == "rich": + oembed_result.html = result.get("html") + return oembed_result + + if oembed_type == "photo": + oembed_result.url = result.get("url") + return oembed_result + + # TODO Handle link and video types. + + if "thumbnail_url" in result: + oembed_result.url = result.get("thumbnail_url") + return oembed_result + + raise OEmbedError("Incompatible oEmbed information.") + + except OEmbedError as e: + # Trap OEmbedErrors first so we can directly re-raise them. + logger.warning("Error parsing oEmbed metadata from %s: %r", url, e) + raise + + except Exception as e: + # Trap any exception and let the code follow as usual. + # FIXME: pass through 404s and other error messages nicely + logger.warning("Error downloading oEmbed metadata from %s: %r", url, e) + raise OEmbedError() from e diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py index 0f051d4041..317d333b12 100644 --- a/synapse/rest/media/v1/preview_url_resource.py +++ b/synapse/rest/media/v1/preview_url_resource.py @@ -25,8 +25,6 @@ import traceback from typing import TYPE_CHECKING, Any, Dict, Generator, Iterable, Optional, Union from urllib import parse as urlparse -import attr - from twisted.internet.error import DNSLookupError from twisted.web.server import Request @@ -43,6 +41,7 @@ from synapse.logging.context import make_deferred_yieldable, run_in_background from synapse.metrics.background_process_metrics import run_as_background_process from synapse.rest.media.v1._base import get_filename_from_headers from synapse.rest.media.v1.media_storage import MediaStorage +from synapse.rest.media.v1.oembed import OEmbedError, OEmbedProvider from synapse.util import json_encoder from synapse.util.async_helpers import ObservableDeferred from synapse.util.caches.expiringcache import ExpiringCache @@ -71,63 +70,6 @@ OG_TAG_VALUE_MAXLEN = 1000 ONE_HOUR = 60 * 60 * 1000 -# A map of globs to API endpoints. -_oembed_globs = { - # Twitter. - "https://publish.twitter.com/oembed": [ - "https://twitter.com/*/status/*", - "https://*.twitter.com/*/status/*", - "https://twitter.com/*/moments/*", - "https://*.twitter.com/*/moments/*", - # Include the HTTP versions too. - "http://twitter.com/*/status/*", - "http://*.twitter.com/*/status/*", - "http://twitter.com/*/moments/*", - "http://*.twitter.com/*/moments/*", - ], -} -# Convert the globs to regular expressions. -_oembed_patterns = {} -for endpoint, globs in _oembed_globs.items(): - for glob in globs: - # Convert the glob into a sane regular expression to match against. The - # rules followed will be slightly different for the domain portion vs. - # the rest. - # - # 1. The scheme must be one of HTTP / HTTPS (and have no globs). - # 2. The domain can have globs, but we limit it to characters that can - # reasonably be a domain part. - # TODO: This does not attempt to handle Unicode domain names. - # 3. Other parts allow a glob to be any one, or more, characters. - results = urlparse.urlparse(glob) - - # Ensure the scheme does not have wildcards (and is a sane scheme). - if results.scheme not in {"http", "https"}: - raise ValueError("Insecure oEmbed glob scheme: %s" % (results.scheme,)) - - pattern = urlparse.urlunparse( - [ - results.scheme, - re.escape(results.netloc).replace("\\*", "[a-zA-Z0-9_-]+"), - ] - + [re.escape(part).replace("\\*", ".+") for part in results[2:]] - ) - _oembed_patterns[re.compile(pattern)] = endpoint - - -@attr.s(slots=True) -class OEmbedResult: - # Either HTML content or URL must be provided. - html = attr.ib(type=Optional[str]) - url = attr.ib(type=Optional[str]) - title = attr.ib(type=Optional[str]) - # Number of seconds to cache the content. - cache_age = attr.ib(type=int) - - -class OEmbedError(Exception): - """An error occurred processing the oEmbed object.""" - class PreviewUrlResource(DirectServeJsonResource): isLeaf = True @@ -157,6 +99,8 @@ class PreviewUrlResource(DirectServeJsonResource): self.primary_base_path = media_repo.primary_base_path self.media_storage = media_storage + self._oembed = OEmbedProvider(hs, self.client) + # We run the background jobs if we're the instance specified (or no # instance is specified, where we assume there is only one instance # serving media). @@ -367,87 +311,6 @@ class PreviewUrlResource(DirectServeJsonResource): return jsonog.encode("utf8") - def _get_oembed_url(self, url: str) -> Optional[str]: - """ - Check whether the URL should be downloaded as oEmbed content instead. - - Args: - url: The URL to check. - - Returns: - A URL to use instead or None if the original URL should be used. - """ - for url_pattern, endpoint in _oembed_patterns.items(): - if url_pattern.fullmatch(url): - return endpoint - - # No match. - return None - - async def _get_oembed_content(self, endpoint: str, url: str) -> OEmbedResult: - """ - Request content from an oEmbed endpoint. - - Args: - endpoint: The oEmbed API endpoint. - url: The URL to pass to the API. - - Returns: - An object representing the metadata returned. - - Raises: - OEmbedError if fetching or parsing of the oEmbed information fails. - """ - try: - logger.debug("Trying to get oEmbed content for url '%s'", url) - result = await self.client.get_json( - endpoint, - # TODO Specify max height / width. - # Note that only the JSON format is supported. - args={"url": url}, - ) - - # Ensure there's a version of 1.0. - if result.get("version") != "1.0": - raise OEmbedError("Invalid version: %s" % (result.get("version"),)) - - oembed_type = result.get("type") - - # Ensure the cache age is None or an int. - cache_age = result.get("cache_age") - if cache_age: - cache_age = int(cache_age) - - oembed_result = OEmbedResult(None, None, result.get("title"), cache_age) - - # HTML content. - if oembed_type == "rich": - oembed_result.html = result.get("html") - return oembed_result - - if oembed_type == "photo": - oembed_result.url = result.get("url") - return oembed_result - - # TODO Handle link and video types. - - if "thumbnail_url" in result: - oembed_result.url = result.get("thumbnail_url") - return oembed_result - - raise OEmbedError("Incompatible oEmbed information.") - - except OEmbedError as e: - # Trap OEmbedErrors first so we can directly re-raise them. - logger.warning("Error parsing oEmbed metadata from %s: %r", url, e) - raise - - except Exception as e: - # Trap any exception and let the code follow as usual. - # FIXME: pass through 404s and other error messages nicely - logger.warning("Error downloading oEmbed metadata from %s: %r", url, e) - raise OEmbedError() from e - async def _download_url(self, url: str, user: str) -> Dict[str, Any]: # TODO: we should probably honour robots.txt... except in practice # we're most likely being explicitly triggered by a human rather than a @@ -459,11 +322,11 @@ class PreviewUrlResource(DirectServeJsonResource): # If this URL can be accessed via oEmbed, use that instead. url_to_download: Optional[str] = url - oembed_url = self._get_oembed_url(url) + oembed_url = self._oembed.get_oembed_url(url) if oembed_url: # The result might be a new URL to download, or it might be HTML content. try: - oembed_result = await self._get_oembed_content(oembed_url, url) + oembed_result = await self._oembed.get_oembed_content(oembed_url, url) if oembed_result.url: url_to_download = oembed_result.url elif oembed_result.html: |