moviewyrm/bookwyrm/incoming.py
2020-12-16 18:40:43 -08:00

350 lines
10 KiB
Python

''' handles all of the activity coming in to the server '''
import json
from urllib.parse import urldefrag
import django.db.utils
from django.http import HttpResponse
from django.http import HttpResponseBadRequest, HttpResponseNotFound
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_POST
import requests
from bookwyrm import activitypub, models, outgoing
from bookwyrm import status as status_builder
from bookwyrm.tasks import app
from bookwyrm.signatures import Signature
@csrf_exempt
@require_POST
def inbox(request, username):
''' incoming activitypub events '''
try:
models.User.objects.get(localname=username)
except models.User.DoesNotExist:
return HttpResponseNotFound()
return shared_inbox(request)
@csrf_exempt
@require_POST
def shared_inbox(request):
''' incoming activitypub events '''
try:
resp = request.body
activity = json.loads(resp)
if isinstance(activity, str):
activity = json.loads(activity)
activity_object = activity['object']
except (json.decoder.JSONDecodeError, KeyError):
return HttpResponseBadRequest()
if not has_valid_signature(request, activity):
if activity['type'] == 'Delete':
# Pretend that unauth'd deletes succeed. Auth may be failing because
# the resource or owner of the resource might have been deleted.
return HttpResponse()
return HttpResponse(status=401)
handlers = {
'Follow': handle_follow,
'Accept': handle_follow_accept,
'Reject': handle_follow_reject,
'Create': handle_create,
'Delete': handle_delete_status,
'Like': handle_favorite,
'Announce': handle_boost,
'Add': {
'Edition': handle_add,
},
'Undo': {
'Follow': handle_unfollow,
'Like': handle_unfavorite,
'Announce': handle_unboost,
},
'Update': {
'Person': handle_update_user,
'Edition': handle_update_edition,
'Work': handle_update_work,
},
}
activity_type = activity['type']
handler = handlers.get(activity_type, None)
if isinstance(handler, dict):
handler = handler.get(activity_object['type'], None)
if not handler:
return HttpResponseNotFound()
handler.delay(activity)
return HttpResponse()
def has_valid_signature(request, activity):
''' verify incoming signature '''
try:
signature = Signature.parse(request)
key_actor = urldefrag(signature.key_id).url
if key_actor != activity.get('actor'):
raise ValueError("Wrong actor created signature.")
remote_user = activitypub.resolve_remote_id(models.User, key_actor)
if not remote_user:
return False
try:
signature.verify(remote_user.key_pair.public_key, request)
except ValueError:
old_key = remote_user.key_pair.public_key
remote_user = activitypub.resolve_remote_id(
models.User, remote_user.remote_id, refresh=True
)
if remote_user.key_pair.public_key == old_key:
raise # Key unchanged.
signature.verify(remote_user.key_pair.public_key, request)
except (ValueError, requests.exceptions.HTTPError):
return False
return True
@app.task
def handle_follow(activity):
''' someone wants to follow a local user '''
try:
relationship = activitypub.Follow(
**activity
).to_model(models.UserFollowRequest)
except django.db.utils.IntegrityError as err:
if err.__cause__.diag.constraint_name != 'userfollowrequest_unique':
raise
relationship = models.UserFollowRequest.objects.get(
remote_id=activity['id']
)
# send the accept normally for a duplicate request
manually_approves = relationship.user_object.manually_approves_followers
status_builder.create_notification(
relationship.user_object,
'FOLLOW_REQUEST' if manually_approves else 'FOLLOW',
related_user=relationship.user_subject
)
if not manually_approves:
outgoing.handle_accept(relationship)
@app.task
def handle_unfollow(activity):
''' unfollow a local user '''
obj = activity['object']
requester = activitypub.resolve_remote_id(models.User, obj['actor'])
to_unfollow = models.User.objects.get(remote_id=obj['object'])
# raises models.User.DoesNotExist
to_unfollow.followers.remove(requester)
@app.task
def handle_follow_accept(activity):
''' hurray, someone remote accepted a follow request '''
# figure out who they want to follow
requester = models.User.objects.get(remote_id=activity['object']['actor'])
# figure out who they are
accepter = activitypub.resolve_remote_id(models.User, activity['actor'])
try:
request = models.UserFollowRequest.objects.get(
user_subject=requester,
user_object=accepter
)
request.delete()
except models.UserFollowRequest.DoesNotExist:
pass
accepter.followers.add(requester)
@app.task
def handle_follow_reject(activity):
''' someone is rejecting a follow request '''
requester = models.User.objects.get(remote_id=activity['object']['actor'])
rejecter = activitypub.resolve_remote_id(models.User, activity['actor'])
request = models.UserFollowRequest.objects.get(
user_subject=requester,
user_object=rejecter
)
request.delete()
#raises models.UserFollowRequest.DoesNotExist
@app.task
def handle_create(activity):
''' someone did something, good on them '''
# deduplicate incoming activities
activity = activity['object']
status_id = activity['id']
if models.Status.objects.filter(remote_id=status_id).count():
return
serializer = activitypub.activity_objects[activity['type']]
activity = serializer(**activity)
try:
model = models.activity_models[activity.type]
except KeyError:
# not a type of status we are prepared to deserialize
return
if activity.type == 'Note':
# keep notes if they are replies to existing statuses
reply = models.Status.objects.filter(
remote_id=activity.inReplyTo
).first()
if not reply:
discard = True
# keep notes if they mention local users
tags = [l['href'] for l in activity.tag if l['type'] == 'Mention']
for tag in tags:
if models.User.objects.filter(
remote_id=tag, local=True).exists():
# we found a mention of a known use boost
discard = False
break
if discard:
return
status = activity.to_model(model)
# create a notification if this is a reply
notified = []
if status.reply_parent and status.reply_parent.user.local:
notified.append(status.reply_parent.user)
status_builder.create_notification(
status.reply_parent.user,
'REPLY',
related_user=status.user,
related_status=status,
)
if status.mention_users.exists():
for mentioned_user in status.mention_users.all():
if not mentioned_user.local or mentioned_user in notified:
continue
status_builder.create_notification(
mentioned_user,
'MENTION',
related_user=status.user,
related_status=status,
)
@app.task
def handle_delete_status(activity):
''' remove a status '''
try:
status_id = activity['object']['id']
except TypeError:
# this isn't a great fix, because you hit this when mastadon
# is trying to delete a user.
return
try:
status = models.Status.objects.get(
remote_id=status_id
)
except models.Status.DoesNotExist:
return
models.Notification.objects.filter(related_status=status).all().delete()
status_builder.delete_status(status)
@app.task
def handle_favorite(activity):
''' approval of your good good post '''
fav = activitypub.Like(**activity)
fav = fav.to_model(models.Favorite)
if fav.user.local:
return
status_builder.create_notification(
fav.status.user,
'FAVORITE',
related_user=fav.user,
related_status=fav.status,
)
@app.task
def handle_unfavorite(activity):
''' approval of your good good post '''
like = models.Favorite.objects.filter(
remote_id=activity['object']['id']
).first()
if not like:
return
like.delete()
@app.task
def handle_boost(activity):
''' someone gave us a boost! '''
try:
boost = activitypub.Boost(**activity).to_model(models.Boost)
except activitypub.ActivitySerializerError:
# this probably just means we tried to boost an unknown status
return
if not boost.user.local:
status_builder.create_notification(
boost.boosted_status.user,
'BOOST',
related_user=boost.user,
related_status=boost.boosted_status,
)
@app.task
def handle_unboost(activity):
''' someone gave us a boost! '''
boost = models.Boost.objects.filter(
remote_id=activity['object']['id']
).first()
if boost:
boost.delete()
@app.task
def handle_add(activity):
''' putting a book on a shelf '''
#this is janky as heck but I haven't thought of a better solution
try:
activitypub.AddBook(**activity).to_model(models.ShelfBook)
except activitypub.ActivitySerializerError:
activitypub.AddBook(**activity).to_model(models.Tag)
@app.task
def handle_update_user(activity):
''' receive an updated user Person activity object '''
try:
user = models.User.objects.get(remote_id=activity['object']['id'])
except models.User.DoesNotExist:
# who is this person? who cares
return
activitypub.Person(
**activity['object']
).to_model(models.User, instance=user)
# model save() happens in the to_model function
@app.task
def handle_update_edition(activity):
''' a remote instance changed a book (Document) '''
activitypub.Edition(**activity['object']).to_model(models.Edition)
@app.task
def handle_update_work(activity):
''' a remote instance changed a book (Document) '''
activitypub.Work(**activity['object']).to_model(models.Work)