From 8b6a26d6b6e71d353a56720e70e786ade69a81de Mon Sep 17 00:00:00 2001
From: tastytea <tastytea@tastytea.de>
Date: Sun, 17 Jan 2021 17:01:46 +0100
Subject: [PATCH] Catch non-targeted spam.

---
 src/cgi.cpp  | 13 +++++++++++++
 src/cgi.hpp  | 10 +++++++++-
 src/main.cpp |  7 ++++++-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/cgi.cpp b/src/cgi.cpp
index a9088a1..b58abab 100644
--- a/src/cgi.cpp
+++ b/src/cgi.cpp
@@ -61,6 +61,13 @@ entry_type parse_formdata()
     entry_type entry;
 
     cgicc::Cgicc cgi;
+
+    // Catch non-targeted spam.
+    if (!cgi("url").empty())
+    {
+        throw SpamException{};
+    }
+
     entry.instance = cgi("instance");
     entry.tags = string_to_vector(cgi("tags"));
     transform(entry.tags.begin(), entry.tags.end(), entry.tags.begin(),
@@ -176,4 +183,10 @@ string text2html(string text)
 
     return text;
 }
+
 } // namespace FediBlock::cgi
+
+const char *SpamException::what() const noexcept
+{
+    return "Spam detected.";
+}
diff --git a/src/cgi.hpp b/src/cgi.hpp
index cb48eff..28b81c1 100644
--- a/src/cgi.hpp
+++ b/src/cgi.hpp
@@ -1,5 +1,5 @@
 /*  This file is part of FediBlock-backend.
- *  Copyright © 2020 tastytea <tastytea@tastytea.de>
+ *  Copyright © 2020, 2021 tastytea <tastytea@tastytea.de>
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU Affero General Public License as published by
@@ -19,6 +19,7 @@
 
 #include "types.hpp"
 
+#include <exception>
 #include <string>
 #include <string_view>
 #include <vector>
@@ -53,4 +54,11 @@ string text2html(string text);
 
 } // namespace FediBlock::cgi
 
+class SpamException : public std::exception
+{
+public:
+    // NOLINTNEXTLINE(modernize-use-nodiscard)
+    const char *what() const noexcept override;
+};
+
 #endif // FEDIBLOCK_BACKEND_CGI_HPP
diff --git a/src/main.cpp b/src/main.cpp
index 7bd9c8d..e78e8ff 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,5 +1,5 @@
 /*  This file is part of FediBlock-backend.
- *  Copyright © 2020 tastytea <tastytea@tastytea.de>
+ *  Copyright © 2020, 2021 tastytea <tastytea@tastytea.de>
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU Affero General Public License as published by
@@ -79,6 +79,11 @@ int main()
 
         files::remove_tmpdir();
     }
+    catch (const SpamException &e)
+    {
+        cerr << e.what() << '\n';
+        cout << e.what() << "\r\n";
+    }
     catch (const exception &e)
     {
         cerr << e.what() << '\n';