Adding a URL max length error.

- Also increasing the post.url max length to 2000 (seems standard)
- I ran into this when fixing torrent support, which often use longer
  urls.

crates/api_crud/src/post/create.rs

@@ -35,11 +35,11 @@ use lemmy_utils::{
   utils::{
     slurs::check_slurs,
     validation::{
-      check_url_scheme,
       is_url_blocked,
       is_valid_alt_text_field,
       is_valid_body_field,
       is_valid_post_title,
+      is_valid_url,
     },
   },
 };
@@ -69,11 +69,11 @@ pub async fn create_post(
 
   if let Some(url) = &url {
     is_url_blocked(url, &url_blocklist)?;
-    check_url_scheme(url)?;
+    is_valid_url(url)?;
   }
 
   if let Some(custom_thumbnail) = &custom_thumbnail {
-    check_url_scheme(custom_thumbnail)?;
+    is_valid_url(custom_thumbnail)?;
   }
 
   if let Some(alt_text) = &data.alt_text {

crates/api_crud/src/post/update.rs

@@ -28,11 +28,11 @@ use lemmy_utils::{
   utils::{
     slurs::check_slurs,
     validation::{
-      check_url_scheme,
       is_url_blocked,
       is_valid_alt_text_field,
       is_valid_body_field,
       is_valid_post_title,
+      is_valid_url,
     },
   },
 };
@@ -77,11 +77,11 @@ pub async fn update_post(
 
   if let Some(Some(url)) = &url {
     is_url_blocked(url, &url_blocklist)?;
-    check_url_scheme(url)?;
+    is_valid_url(url)?;
   }
 
   if let Some(Some(custom_thumbnail)) = &custom_thumbnail {
-    check_url_scheme(custom_thumbnail)?;
+    is_valid_url(custom_thumbnail)?;
   }
 
   let post_id = data.post_id;

crates/apub/src/objects/post.rs

@@ -41,7 +41,7 @@ use lemmy_db_views_actor::structs::CommunityModeratorView;
 use lemmy_utils::{
   error::{LemmyError, LemmyErrorType, LemmyResult},
   spawn_try_task,
-  utils::{markdown::markdown_to_html, slurs::check_slurs_opt, validation::check_url_scheme},
+  utils::{markdown::markdown_to_html, slurs::check_slurs_opt, validation::is_valid_url},
 };
 use std::ops::Deref;
 use stringreader::StringReader;
@@ -221,7 +221,7 @@ impl Object for ApubPost {
     };
 
     if let Some(url) = &url {
-      check_url_scheme(url)?;
+      is_valid_url(url)?;
     }
 
     let alt_text = first_attachment.cloned().and_then(Attachment::alt_text);

crates/db_schema/src/schema.rs

@@ -711,7 +711,7 @@ diesel::table! {
         id -> Int4,
         #[max_length = 200]
         name -> Varchar,
-        #[max_length = 512]
+        #[max_length = 2000]
         url -> Nullable<Varchar>,
         body -> Nullable<Text>,
         creator_id -> Int4,

crates/utils/src/error.rs

@@ -180,6 +180,7 @@ pub enum LemmyErrorType {
   InboxTimeout,
   Unknown(String),
   CantDeleteSite,
+  UrlLengthOverflow,
 }
 
 cfg_if! {

crates/utils/src/utils/validation.rs

@@ -21,6 +21,7 @@ const ALLOWED_POST_URL_SCHEMES: [&str; 3] = ["http", "https", "magnet"];
 const BODY_MAX_LENGTH: usize = 10000;
 const POST_BODY_MAX_LENGTH: usize = 50000;
 const BIO_MAX_LENGTH: usize = 300;
+const URL_MAX_LENGTH: usize = 2000;
 const ALT_TEXT_MAX_LENGTH: usize = 1500;
 const SITE_NAME_MAX_LENGTH: usize = 20;
 const SITE_NAME_MIN_LENGTH: usize = 1;
@@ -284,11 +285,17 @@ pub fn check_site_visibility_valid(
   }
 }
 
-pub fn check_url_scheme(url: &Url) -> LemmyResult<()> {
+pub fn is_valid_url(url: &Url) -> LemmyResult<()> {
   if !ALLOWED_POST_URL_SCHEMES.contains(&url.scheme()) {
     Err(LemmyErrorType::InvalidUrlScheme)?
   }
 
+  max_length_check(
+    url.as_str(),
+    URL_MAX_LENGTH,
+    LemmyErrorType::UrlLengthOverflow,
+  )?;
+
   Ok(())
 }
 
@@ -349,7 +356,6 @@ mod tests {
     utils::validation::{
       build_and_check_regex,
       check_site_visibility_valid,
-      check_url_scheme,
       check_urls_are_valid,
       clean_url_params,
       is_url_blocked,
@@ -358,11 +364,13 @@ mod tests {
       is_valid_display_name,
       is_valid_matrix_id,
       is_valid_post_title,
+      is_valid_url,
       site_description_length_check,
       site_name_length_check,
       BIO_MAX_LENGTH,
       SITE_DESCRIPTION_MAX_LENGTH,
       SITE_NAME_MAX_LENGTH,
+      URL_MAX_LENGTH,
     },
   };
   use pretty_assertions::assert_eq;
@@ -580,15 +588,27 @@ mod tests {
   }
 
   #[test]
-  fn test_check_url_scheme() -> LemmyResult<()> {
-    assert!(check_url_scheme(&Url::parse("http://example.com")?).is_ok());
-    assert!(check_url_scheme(&Url::parse("https://example.com")?).is_ok());
-    assert!(check_url_scheme(&Url::parse("https://example.com")?).is_ok());
-    assert!(check_url_scheme(&Url::parse("ftp://example.com")?).is_err());
-    assert!(check_url_scheme(&Url::parse("javascript:void")?).is_err());
+  fn test_check_url_valid() -> LemmyResult<()> {
+    assert!(is_valid_url(&Url::parse("http://example.com")?).is_ok());
+    assert!(is_valid_url(&Url::parse("https://example.com")?).is_ok());
+    assert!(is_valid_url(&Url::parse("https://example.com")?).is_ok());
+    assert!(is_valid_url(&Url::parse("ftp://example.com")?)
+      .is_err_and(|e| e.error_type.eq(&LemmyErrorType::InvalidUrlScheme)));
+    assert!(is_valid_url(&Url::parse("javascript:void")?)
+      .is_err_and(|e| e.error_type.eq(&LemmyErrorType::InvalidUrlScheme)));
 
     let magnet_link="magnet:?xt=urn:btih:4b390af3891e323778959d5abfff4b726510f14c&dn=Ravel%20Complete%20Piano%20Sheet%20Music%20-%20Public%20Domain&tr=udp%3A%2F%2Fopen.tracker.cl%3A1337%2Fannounce";
-    assert!(check_url_scheme(&Url::parse(magnet_link)?).is_ok());
+    assert!(is_valid_url(&Url::parse(magnet_link)?).is_ok());
+
+    // Also make sure the length overflow hits an error
+    let mut long_str = "http://example.com/test=".to_string();
+    for _ in 1..URL_MAX_LENGTH {
+      long_str.push('X');
+    }
+    let long_url = Url::parse(&long_str)?;
+    assert!(
+      is_valid_url(&long_url).is_err_and(|e| e.error_type.eq(&LemmyErrorType::UrlLengthOverflow))
+    );
 
     Ok(())
   }

migrations/2024-08-03-155932_increase_post_url_max_length/down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE post
+    ALTER COLUMN url TYPE varchar(512);

migrations/2024-08-03-155932_increase_post_url_max_length/up.sql

@@ -0,0 +1,4 @@
+-- Change the post url max limit to 2000
+-- From here: https://stackoverflow.com/questions/417142/what-is-the-maximum-length-of-a-url-in-different-browsers#417184
+ALTER TABLE post
+    ALTER COLUMN url TYPE varchar(2000);