Add IP bans

Users can be banned by IP address now, either by singular IP or in an IP
range. If they are banned and attempt to post, they will be met with a
"you are banned until X date" screen.

There are a few loose threads with this, and IP bans may be obsolete if
I decide to go the accounts-required-for-posting route. But I think this
is a good start for 4chan style posting.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/admin.py

@@ -1,6 +1,6 @@
 from django.contrib import admin
 from django.utils.safestring import mark_safe
-from board.models import Board, Post, ReportReason, ReportRecord
+from board.models import Ban, Board, Post, RangeBan, ReportReason, ReportRecord
 
 
 @admin.register(Board)
@@ -45,3 +45,13 @@ class ReportRecordAdmin(admin.ModelAdmin):
         html += f"<p>{obj.post.text}</p>"
         html += "</div>"
         return mark_safe(html)
+
+
+@admin.register(RangeBan)
+class RangeBanAdmin(admin.ModelAdmin):
+    pass
+
+
+@admin.register(Ban)
+class BanAdmin(admin.ModelAdmin):
+    pass

board/models.py

@@ -264,32 +264,50 @@ def report_created(sender, instance, created, **kwargs):
 # board =
 
 
-class RangeBan(models.Model):
-    # Starting IP address of the ban
-    start = models.GenericIPAddressField()
-    # Ending IP address of the ban
-    end = models.GenericIPAddressField()
-    # The reason for this ban
-    ban_reason = models.TextField(blank=False)
-    # The time that this ban was created.
-    created = models.DateTimeField(auto_now_add=True)
-    # Expiration date of this ban. If it is null, it is permanent.
-    expires = models.DateTimeField(null=True)
-
-
-class Ban(models.Model):
-    # IP address of the ban
-    ip = models.GenericIPAddressField()
+class BanCommon(models.Model):
     # The reason for this ban
     ban_reason = models.TextField(blank=False)
     # Board that this ban is for. If null, then all boards.
     # Even though this is nullable, we just want to delete all reports for a
     # board if that board is deleted.
-    board = models.ForeignKey("Board", on_delete=models.CASCADE, null=True)
+    board = models.ForeignKey("Board", on_delete=models.CASCADE, null=True, blank=True)
     # The time that this ban was created.
     created = models.DateTimeField(auto_now_add=True)
     # Expiration date of this ban. If it is null, it is permanent.
-    expires = models.DateTimeField(null=True)
+    expires = models.DateTimeField(null=True, blank=True)
+
+    class Meta:
+        abstract = True
+
+
+class RangeBan(BanCommon):
+    # Starting IP address of the ban
+    start = models.GenericIPAddressField()
+    # Ending IP address of the ban
+    end = models.GenericIPAddressField()
+
+    def clean(self):
+        import ipaddress
+
+        start = ipaddress.ip_address(self.start)
+        end = ipaddress.ip_address(self.end)
+        if start.version != end.version:
+            raise ValidationError(
+                _("Start and end IP address must be the same protocol (IPv4 or IPv6)")
+            )
+        if start >= end:
+            raise ValidationError(_("Start IP must be lower than end IP"))
+
+    def __str__(self):
+        return f"Range ban for {self.start}-{self.end}"
+
+
+class Ban(BanCommon):
+    # IP address of the ban
+    ip = models.GenericIPAddressField(unique=True)
+
+    def __str__(self):
+        return f"Ban for {self.ip}"
 
 
 class BanTemplate(models.Model):

board/templates/board/banned.html

@@ -0,0 +1,81 @@
+{% extends "board/base.html" %}
+
+{% block title %}
+    {% if bans %}
+        {% with title="Banned" %}
+            {{ block.super }}
+        {% endwith %}
+    {% else %}
+        {% with title="Not banned" %}
+            {{ block.super }}
+        {% endwith %}
+    {% endif %}
+{% endblock title %}
+
+{% block extrastyle %}
+{{block.super}}
+<style>
+.blankcolumn {
+    float: left;
+    width: 20%;
+}
+.bancolumn {
+    float: left;
+    width: 60%;
+}
+</style>
+{% endblock extrastyle %}
+
+{% block content %}
+<div class="row">
+    <div class="blankcolumn">&nbsp;</div>
+    <div class="bancolumn">
+        {% if bans %}
+            <div class="row">
+                <h2>You are banned.</h2>
+            </div>
+            <div class="row">
+                <p>
+                You have been banned, and you are not allowed to post until your
+                bans have expired.
+                </p>
+                <p>
+                    <strong>Your IP address:</strong> {{ip}}
+                </p>
+            </div>
+            <hr />
+            {% for ban in bans %}
+            <div class="row">
+                <p>
+                    <strong>Board:</strong>
+                    {% if ban.board %}
+                        /{{ ban.board.url }}/ - {{ ban.board.name }}
+                    {% else %}
+                        All boards
+                    {% endif %}
+                </p>
+                <p>
+                    <strong>Ban reason:</strong>
+                </p>
+                <p>{{ban.ban_reason}}</p>
+                <p><strong>
+                {% if ban.expires %}
+                    This ban will expire on {{ban.expires|date:"M dS"}} at {{ban.expires|date:"P e"}}
+                {% else %}
+                    This ban will not expire.
+                {% endif %}
+                </strong></p>
+            </div>
+            <hr />
+            {% endfor %}
+        {% else %}
+            <div class="row">
+                <h2>You are not banned.</h2>
+            </div>
+            <div class="row">
+                <p>You have no bans recorded for your IP address.</p>
+            </div>
+        {% endif %}
+    </div>
+    <div class="blankcolumn">&nbsp;</div>
+{% endblock %}

board/templates/board/base.html

@@ -7,9 +7,11 @@
         <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
         <title>{% block title %}{% if title %}{{title}}{% else %}Index{% endif %}{% endblock %}</title>
         <link rel="stylesheet" href="{% static 'board/style.css' %}">
+        {% block extrastyle %}{% endblock %}
         <script src="{% static 'board/jquery.js' %}"></script>
         <script src="{% static 'board/winbox.bundle.js' %}"></script>
         <script src="{% static 'board/post.js' %}"></script>
+        {% block extrajs %}{% endblock %}
     </head>
     <body>
         <main>

board/urls.py

@@ -16,6 +16,11 @@ urlpatterns = [
         TemplateView.as_view(template_name="board/report_success.html"),
         name="report_success",
     ),
+    path(
+        "banned",
+        BannedView.as_view(),
+        name="banned",
+    ),
 ]
 # TODO - make this conditional so we can serve images up with whatever server we want
 urlpatterns += static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

board/utils.py

@@ -0,0 +1,26 @@
+from board.models import Ban, RangeBan
+import ipaddress
+
+
+def get_client_ip(request):
+    "Get the IP address of a client-side request. Shamelessly copy/pasted from StackOverflow."
+    x_forwarded_for = request.META.get("HTTP_X_FORWARDED_FOR")
+    if x_forwarded_for:
+        ip = x_forwarded_for.split(",")[0]
+    else:
+        ip = request.META.get("REMOTE_ADDR")
+    return ip
+
+
+def get_ip_bans(ip: str) -> list:
+    bans = list(Ban.objects.filter(ip=ip))
+
+    ip_addr = ipaddress.ip_address(ip)
+    for rangeban in RangeBan.objects.all():
+        start = ipaddress.ip_address(rangeban.start)
+        end = ipaddress.ip_address(rangeban.end)
+        if ip_addr.version != start.version or ip_addr.version != end.version:
+            continue
+        if start <= ip_addr <= end:  # type: ignore
+            bans += [rangeban]
+    return bans

board/views.py

@@ -1,23 +1,27 @@
 from django.conf import settings
 from django.http import Http404, HttpResponseRedirect
-from django.shortcuts import render, get_object_or_404
+from django.shortcuts import get_object_or_404
 from django.views.generic import DetailView
+from django.views.generic.base import TemplateView
 from django.views.generic.edit import CreateView
 from django.urls import reverse, reverse_lazy
-from board.models import Post, Board, Report, ReportRecord
 from board.forms import PostForm, ReplyForm, ReportForm
+from board.models import Ban, Post, Board, Report
+from board.utils import get_client_ip, get_ip_bans
 
-__all__ = ("BoardView", "PostView", "ReportView")
+__all__ = ("BannedView", "BoardView", "PostView", "ReportView")
 
 
-def get_client_ip(request):
-    "Get the IP address of a client-side request. Shamelessly copy/pasted from StackOverflow."
-    x_forwarded_for = request.META.get("HTTP_X_FORWARDED_FOR")
-    if x_forwarded_for:
-        ip = x_forwarded_for.split(",")[0]
-    else:
-        ip = request.META.get("REMOTE_ADDR")
-    return ip
+class BannedView(TemplateView):
+    template_name = "board/banned.html"
+
+    def get_context_data(self, **kwargs):
+        context = super(TemplateView, self).get_context_data(**kwargs)
+        ip = get_client_ip(self.request)
+        bans = get_ip_bans(ip)
+        context["bans"] = bans
+        context["ip"] = ip
+        return context
 
 
 class CreatePostView(CreateView):
@@ -46,6 +50,20 @@ class CreatePostView(CreateView):
         kwargs["ip"] = get_client_ip(self.request)
         return kwargs
 
+    def dispatch(self, request, *args, **kwargs):
+        self._set_board(kwargs["url"])
+        if request.method == "POST":
+            ip = get_client_ip(request)
+            bans = [
+                ban
+                for ban in get_ip_bans(ip)
+                if ban.board == self.board or not ban.board
+            ]
+            if bans:
+                return HttpResponseRedirect(reverse("board:banned"))
+
+        return super(CreatePostView, self).dispatch(request, *args, **kwargs)
+
 
 class BoardView(CreatePostView):
     model = Post