block future shitpost floods

app/activitypub/util.py

@@ -24,7 +24,8 @@ import pytesseract
 
 from app.utils import get_request, allowlist_html, html_to_markdown, get_setting, ap_datetime, markdown_to_html, \
     is_image_url, domain_from_url, gibberish, ensure_directory_exists, markdown_to_text, head_request, post_ranking, \
-    shorten_string, reply_already_exists, reply_is_just_link_to_gif_reaction, confidence, remove_tracking_from_link
+    shorten_string, reply_already_exists, reply_is_just_link_to_gif_reaction, confidence, remove_tracking_from_link, \
+    blocked_phrases
 
 
 def public_key():
@@ -1177,9 +1178,11 @@ def create_post_reply(activity_log: ActivityPubLog, community: Community, in_rep
             post_reply.body_html = allowlist_html(request_json['object']['content'])
             post_reply.body = html_to_markdown(post_reply.body_html)
         if post_id is not None:
-            # block shitpost flood
+            # Discard post_reply if it contains certain phrases. Good for stopping spam floods.
-            if post_reply.body and "SNEED'S" in post_reply.body:
+            if post_reply.body:
-                return None
+                for blocked_phrase in blocked_phrases():
+                    if blocked_phrase in post_reply.body:
+                        return None
             post = Post.query.get(post_id)
             if post.comments_enabled:
                 anchor = None
@@ -1273,6 +1276,15 @@ def create_post(activity_log: ActivityPubLog, community: Community, request_json
     elif 'content' in request_json['object'] and request_json['object']['content'] is not None: # Kbin
         post.body_html = allowlist_html(request_json['object']['content'])
         post.body = html_to_markdown(post.body_html)
+    # Discard post if it contains certain phrases. Good for stopping spam floods.
+    blocked_phrases_list = blocked_phrases()
+    for blocked_phrase in blocked_phrases_list:
+        if blocked_phrase in post.title:
+            return None
+    if post.body:
+        for blocked_phrase in blocked_phrases_list:
+            if blocked_phrase in post.body:
+                return None
     if 'attachment' in request_json['object'] and len(request_json['object']['attachment']) > 0 and \
             'type' in request_json['object']['attachment'][0]:
         if request_json['object']['attachment'][0]['type'] == 'Link':

app/admin/forms.py

@@ -41,6 +41,7 @@ class FederationForm(FlaskForm):
     allowlist = TextAreaField(_l('Allow federation with these instances'))
     use_blocklist = BooleanField(_l('Blocklist instead of allowlist'))
     blocklist = TextAreaField(_l('Deny federation with these instances'))
+    blocked_phrases = TextAreaField(_l('Discard all posts and comments with these phrases (one per line)'))
     submit = SubmitField(_l('Save'))
 
 

app/admin/routes.py

@@ -6,10 +6,10 @@ from flask_login import login_required, current_user
 from flask_babel import _
 from sqlalchemy import text, desc
 
-from app import db, celery
+from app import db, celery, cache
 from app.activitypub.routes import process_inbox_request, process_delete_request
 from app.activitypub.signature import post_request
-from app.activitypub.util import default_context
+from app.activitypub.util import default_context, instance_allowed, instance_blocked
 from app.admin.forms import FederationForm, SiteMiscForm, SiteProfileForm, EditCommunityForm, EditUserForm, \
     EditTopicForm, SendNewsletterForm, AddUserForm
 from app.admin.util import unsubscribe_from_everything_then_delete, unsubscribe_from_community, send_newsletter, \
@@ -18,7 +18,7 @@ from app.community.util import save_icon_file, save_banner_file
 from app.models import AllowedInstances, BannedInstances, ActivityPubLog, utcnow, Site, Community, CommunityMember, \
     User, Instance, File, Report, Topic, UserRegistration, Role, Post
 from app.utils import render_template, permission_required, set_setting, get_setting, gibberish, markdown_to_html, \
-    moderating_communities, joined_communities, finalize_user_setup, theme_list
+    moderating_communities, joined_communities, finalize_user_setup, theme_list, blocked_phrases
 from app.admin import bp
 
 
@@ -123,13 +123,18 @@ def admin_federation():
             for allow in form.allowlist.data.split('\n'):
                 if allow.strip():
                     db.session.add(AllowedInstances(domain=allow.strip()))
+                    cache.delete_memoized(instance_allowed, allow.strip())
         if form.use_blocklist.data:
             set_setting('use_allowlist', False)
             db.session.execute(text('DELETE FROM banned_instances'))
             for banned in form.blocklist.data.split('\n'):
                 if banned.strip():
                     db.session.add(BannedInstances(domain=banned.strip()))
+                    cache.delete_memoized(instance_blocked, banned.strip())
+        site.blocked_phrases = form.blocked_phrases.data
+        cache.delete_memoized(blocked_phrases)
         db.session.commit()
+
         flash(_('Admin settings saved'))
 
     elif request.method == 'GET':
@@ -139,6 +144,7 @@ def admin_federation():
         form.blocklist.data = '\n'.join([instance.domain for instance in instances])
         instances = AllowedInstances.query.all()
         form.allowlist.data = '\n'.join([instance.domain for instance in instances])
+        form.blocked_phrases.data = site.blocked_phrases
 
     return render_template('admin/federation.html', title=_('Federation settings'), form=form,
                            moderating_communities=moderating_communities(current_user.get_id()),

app/community/util.py

@@ -16,7 +16,7 @@ from app.models import Community, File, BannedInstances, PostReply, PostVote, Po
     Instance, Notification, User, ActivityPubLog
 from app.utils import get_request, gibberish, markdown_to_html, domain_from_url, allowlist_html, \
     html_to_markdown, is_image_url, ensure_directory_exists, inbox_domain, post_ranking, shorten_string, parse_page, \
-    remove_tracking_from_link, ap_datetime, instance_banned
+    remove_tracking_from_link, ap_datetime, instance_banned, blocked_phrases
 from sqlalchemy import func, desc
 import os
 
@@ -299,6 +299,19 @@ def save_post(form, post: Post):
         if current_user.reputation < -100:
             post.score = -1
         post.ranking = post_ranking(post.score, utcnow())
+
+        # Filter by phrase
+        blocked_phrases_list = blocked_phrases()
+        for blocked_phrase in blocked_phrases_list:
+            if blocked_phrase in post.title:
+                abort(401)
+                return
+        if post.body:
+            for blocked_phrase in blocked_phrases_list:
+                if blocked_phrase in post.body:
+                    abort(401)
+                    return
+
         db.session.add(post)
 
     g.site.last_active = utcnow()

app/models.py

@@ -1170,7 +1170,8 @@ class Site(db.Model):
     allow_or_block_list = db.Column(db.Integer, default=2)  # 1 = allow list, 2 = block list
     allowlist = db.Column(db.Text, default='')
     blocklist = db.Column(db.Text, default='')
-    auto_decline_referrers = db.Column(db.Text, default='rdrama.net')
+    blocked_phrases = db.Column(db.Text, default='')                     # discard incoming content with these phrases
+    auto_decline_referrers = db.Column(db.Text, default='rdrama.net')   # automatically decline registration requests if the referrer is one of these
     created_at = db.Column(db.DateTime, default=utcnow)
     updated = db.Column(db.DateTime, default=utcnow)
     last_active = db.Column(db.DateTime, default=utcnow)

app/post/routes.py

@@ -24,7 +24,7 @@ from app.utils import get_setting, render_template, allowlist_html, markdown_to_
     shorten_string, markdown_to_text, gibberish, ap_datetime, return_304, \
     request_etag_matches, ip_address, user_ip_banned, instance_banned, can_downvote, can_upvote, post_ranking, \
     reply_already_exists, reply_is_just_link_to_gif_reaction, confidence, moderating_communities, joined_communities, \
-    blocked_instances, blocked_domains, community_moderators
+    blocked_instances, blocked_domains, community_moderators, blocked_phrases
 
 
 def show_post(post_id: int):
@@ -466,6 +466,10 @@ def add_reply(post_id: int, comment_id: int):
                           body_html=markdown_to_html(form.body.data), body_html_safe=True,
                           from_bot=current_user.bot, nsfw=post.nsfw, nsfl=post.nsfl,
                           notify_author=form.notify_author.data, instance_id=1)
+        if reply.body:
+            for blocked_phrase in blocked_phrases():
+                if blocked_phrase in reply.body:
+                    abort(401)
         db.session.add(reply)
         if in_reply_to.notify_author and current_user.id != in_reply_to.user_id and in_reply_to.author.ap_id is None:    # todo: check if replier is blocked
             notification = Notification(title=shorten_string(_('Reply from %(name)s on %(post_title)s',

app/utils.py

@@ -330,6 +330,15 @@ def blocked_instances(user_id) -> List[int]:
     return [block.instance_id for block in blocks]
 
 
+@cache.memoize(timeout=86400)
+def blocked_phrases() -> List[str]:
+    site = Site.query.get(1)
+    if site.blocked_phrases:
+        return [phrase for phrase in site.blocked_phrases.split('\n') if phrase != '']
+    else:
+        return []
+
+
 def retrieve_block_list():
     try:
         response = requests.get('https://raw.githubusercontent.com/rimu/no-qanon/master/domains.txt', timeout=1)

migrations/versions/2b028a70bd7a_blocked_phrases.py

@@ -0,0 +1,32 @@
+"""blocked phrases
+
+Revision ID: 2b028a70bd7a
+Revises: 12d60b9d5417
+Create Date: 2024-03-22 11:50:15.405786
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '2b028a70bd7a'
+down_revision = '12d60b9d5417'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('site', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('blocked_phrases', sa.Text(), nullable=True))
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('site', schema=None) as batch_op:
+        batch_op.drop_column('blocked_phrases')
+
+    # ### end Alembic commands ###