Send response on quota exceeded

So far, slcl would just close the connection with a client when the
Content-Length of an incoming request exceeded the user quota, without
any meaningful information given back to the user.

Now, slcl responds with a HTML file with meaningful information about
the error.

Limitations:

- While this commits has been successfully tested on ungoogled-chromium,
LibreWolf (and I assume Firefox and any other derivates too) does not
seem to receive the response from the server.
    - However, this issue only occurred during local testing, but not
on remote instances.

1 files changed, 12 insertions, 2 deletions

diff --git a/main.c b/main.c
index 6e461b3..89edae3 100644
--- a/main.c
+++ b/main.c
@@ -610,7 +610,8 @@ static int check_quota(const struct auth *const a, const char *const username,
 }
 
 static int check_length(const unsigned long long len,
-    const struct http_cookie *const c, void *const user)
+    const struct http_cookie *const c, struct http_response *const r,
+    void *const user)
 {
     struct auth *const a = user;
     const char *const username = c->field;
@@ -623,7 +624,16 @@ static int check_length(const unsigned long long len,
         return -1;
     }
     else if (has_quota)
-        return check_quota(a, username, len, quota);
+    {
+        int res = check_quota(a, username, len, quota);
+
+        if (res < 0)
+            fprintf(stderr, "%s: check_quota failed\n", __func__);
+        else if (res > 0 && page_quota_exceeded(r, len, quota) < 0)
+            return -1;
+
+        return res;
+    }
 
     return 0;
 }