[Minor] Unify converters usage

src/libmime/archives.c

@@ -67,7 +67,8 @@ rspamd_archive_file_try_utf (struct rspamd_task *task,
 		struct rspamd_charset_converter *conv;
 		UConverter *utf8_converter;
 
-		conv = rspamd_mime_get_converter_cached (charset, &uc_err);
+		conv = rspamd_mime_get_converter_cached (charset, task->task_pool,
+				FALSE, &uc_err);
 		utf8_converter = rspamd_get_utf8_converter ();
 
 		if (conv == NULL) {

src/libmime/mime_encoding.c

@@ -135,7 +135,10 @@ rspamd_converter_to_uchars (struct rspamd_charset_converter *cnv,
 
 
 struct rspamd_charset_converter *
-rspamd_mime_get_converter_cached (const gchar *enc, UErrorCode *err)
+rspamd_mime_get_converter_cached (const gchar *enc,
+								  rspamd_mempool_t *pool,
+								  gboolean is_canon,
+								  UErrorCode *err)
 {
 	const gchar *canon_name;
 	static rspamd_lru_hash_t *cache;
@@ -147,7 +150,19 @@ rspamd_mime_get_converter_cached (const gchar *enc, UErrorCode *err)
 				rspamd_str_equal);
 	}
 
-	canon_name = ucnv_getStandardName (enc, "IANA", err);
+	if (enc == NULL) {
+		return NULL;
+	}
+
+	if (!is_canon) {
+		rspamd_ftok_t cset_tok;
+
+		RSPAMD_FTOK_FROM_STR (&cset_tok, enc);
+		canon_name = rspamd_mime_detect_charset (&cset_tok, pool);
+	}
+	else {
+		canon_name = enc;
+	}
 
 	if (canon_name == NULL) {
 		return NULL;
@@ -306,7 +321,7 @@ rspamd_mime_text_to_utf8 (rspamd_mempool_t *pool,
 	UConverter *utf8_converter;
 	struct rspamd_charset_converter *conv;
 
-	conv = rspamd_mime_get_converter_cached (in_enc, &uc_err);
+	conv = rspamd_mime_get_converter_cached (in_enc, pool, TRUE, &uc_err);
 	utf8_converter = rspamd_get_utf8_converter ();
 
 	if (conv == NULL) {
@@ -370,7 +385,8 @@ rspamd_mime_text_part_utf8_convert (struct rspamd_task *task,
 	UConverter *utf8_converter;
 	struct rspamd_charset_converter *conv;
 
-	conv = rspamd_mime_get_converter_cached (charset, &uc_err);
+	conv = rspamd_mime_get_converter_cached (charset, task->task_pool,
+			TRUE, &uc_err);
 	utf8_converter = rspamd_get_utf8_converter ();
 
 	if (conv == NULL) {
@@ -429,6 +445,7 @@ rspamd_mime_text_part_utf8_convert (struct rspamd_task *task,
 gboolean
 rspamd_mime_to_utf8_byte_array (GByteArray *in,
 		GByteArray *out,
+		rspamd_mempool_t *pool,
 		const gchar *enc)
 {
 	gint32 r, clen, dlen;
@@ -438,6 +455,24 @@ rspamd_mime_to_utf8_byte_array (GByteArray *in,
 	struct rspamd_charset_converter *conv;
 	rspamd_ftok_t charset_tok;
 
+	if (in == NULL || in->len == 0) {
+		return FALSE;
+	}
+
+	if (enc == NULL) {
+		/* Assume utf ? */
+		if (rspamd_fast_utf8_validate (in->data, in->len) == 0) {
+			g_byte_array_set_size (out, in->len);
+			memcpy (out->data, in->data, out->len);
+
+			return TRUE;
+		}
+		else {
+			/* Bad stuff, keep out */
+			return FALSE;
+		}
+	}
+
 	RSPAMD_FTOK_FROM_STR (&charset_tok, enc);
 
 	if (rspamd_mime_charset_utf_check (&charset_tok, (gchar *)in->data, in->len,
@@ -449,7 +484,7 @@ rspamd_mime_to_utf8_byte_array (GByteArray *in,
 	}
 
 	utf8_converter = rspamd_get_utf8_converter ();
-	conv = rspamd_mime_get_converter_cached (enc, &uc_err);
+	conv = rspamd_mime_get_converter_cached (enc, pool, TRUE, &uc_err);
 
 	if (conv == NULL) {
 		return FALSE;

src/libmime/mime_encoding.h

@@ -47,7 +47,7 @@ const gchar *rspamd_mime_detect_charset (const rspamd_ftok_t *in,
  * @param pool
  * @param input
  * @param len
- * @param in_enc
+ * @param in_enc canon charset
  * @param olen
  * @param err
  * @return
@@ -57,14 +57,20 @@ gchar *rspamd_mime_text_to_utf8 (rspamd_mempool_t *pool,
 								 gsize *olen, GError **err);
 
 /**
- * Converts data from `in` to `out`, returns `FALSE` if `enc` is not a valid iconv charset
+ * Converts data from `in` to `out`,
+ * returns `FALSE` if `enc` is not a valid iconv charset
+ *
+ * This function, in fact, copies `in` from `out` replacing out content in
+ * total.
  * @param in
  * @param out
- * @param enc
+ * @param enc validated canonical charset name. If NULL, then utf8 check is done only
  * @return
  */
 gboolean rspamd_mime_to_utf8_byte_array (GByteArray *in,
-										 GByteArray *out, const gchar *enc);
+										 GByteArray *out,
+										 rspamd_mempool_t *pool,
+										 const gchar *enc);
 
 /**
  * Maybe convert part to utf-8
@@ -83,7 +89,8 @@ void rspamd_mime_text_part_maybe_convert (struct rspamd_task *task,
  * @return
  */
 gboolean rspamd_mime_charset_utf_check (rspamd_ftok_t *charset,
-										gchar *in, gsize len, gboolean content_check);
+										gchar *in, gsize len,
+										gboolean content_check);
 
 /**
  * Ensure that all characters in string are valid utf8 chars or replace them
@@ -93,14 +100,18 @@ gboolean rspamd_mime_charset_utf_check (rspamd_ftok_t *charset,
  */
 void rspamd_mime_charset_utf_enforce (gchar *in, gsize len);
 
-/**
- * Gets cached converter
- * @param enc
- * @param err
- * @return
- */
+ /**
+  * Gets cached converter
+  * @param enc input encoding
+  * @param pool pool to use for temporary normalisation
+  * @param is_canon TRUE if normalisation is needed
+  * @param err output error
+  * @return converter
+  */
 struct rspamd_charset_converter *rspamd_mime_get_converter_cached (
 		const gchar *enc,
+		rspamd_mempool_t *pool,
+		gboolean is_canon,
 		UErrorCode *err);
 
 /**

src/libmime/mime_headers.c

@@ -512,9 +512,12 @@ rspamd_mime_headers_process (struct rspamd_task *task,
 }
 
 static void
-rspamd_mime_header_maybe_save_token (rspamd_mempool_t *pool, GString *out,
-		GByteArray *token, GByteArray *decoded_token,
-		rspamd_ftok_t *old_charset, rspamd_ftok_t *new_charset)
+rspamd_mime_header_maybe_save_token (rspamd_mempool_t *pool,
+									 GString *out,
+									 GByteArray *token,
+									 GByteArray *decoded_token,
+									 rspamd_ftok_t *old_charset,
+									 rspamd_ftok_t *new_charset)
 {
 	if (new_charset->len == 0) {
 		g_assert_not_reached ();
@@ -538,14 +541,22 @@ rspamd_mime_header_maybe_save_token (rspamd_mempool_t *pool, GString *out,
 	}
 
 	/* We need to flush and decode old token to out string */
-	if (rspamd_mime_to_utf8_byte_array (token, decoded_token,
+	if (rspamd_mime_to_utf8_byte_array (token, decoded_token, pool,
 			rspamd_mime_detect_charset (new_charset, pool))) {
 		g_string_append_len (out, decoded_token->data, decoded_token->len);
 	}
 
 	/* We also reset buffer */
 	g_byte_array_set_size (token, 0);
-	/* Propagate charset */
+	/*
+	 * Propagate charset
+	 *
+	 * Here are dragons: we save the original charset to allow buffers concat
+	 * in the condition at the beginning of the function.
+	 * However, it will likely cause unnecessary calls for
+	 * `rspamd_mime_detect_charset` which could be relatively expensive.
+	 * But we ignore that for now...
+	 */
 	memcpy (old_charset, new_charset, sizeof (*old_charset));
 }