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:
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