Implement basec alert sending

lib/backends/native/alert_io.c

@@ -19,3 +19,46 @@
 #include "alert_messages.h"
 #include "sln_tok.h"
 
+static selene_error_t *
+sln_io_alert(selene_t *s, sln_alert_level_e level, sln_alert_description_e desc)
+{
+  selene_error_t *err;
+  sln_bucket_t *btls = NULL;
+  sln_bucket_t *balert = NULL;
+  sln_msg_alert_t alert;
+  sln_native_msg_tls_t tls;
+
+  alert.level =  level;
+  alert.description = desc;
+
+  SELENE_ERR(sln_alert_unparse(&alert, &balert));
+
+  if (err) {
+    return err;
+  }
+
+  tls.content_type = SLN_NATIVE_CONTENT_TYPE_ALERT;
+  tls.version_major = 3;
+  tls.version_minor = 1;
+  tls.length = balert->size;
+
+  SELENE_ERR(sln_tls_unparse_header(&tls, &btls));
+
+  SLN_BRIGADE_INSERT_TAIL(s->bb.out_enc, btls);
+
+  SLN_BRIGADE_INSERT_TAIL(s->bb.out_enc, balert);
+
+  return err;
+}
+
+selene_error_t *
+sln_io_alert_fatal(selene_t *s, sln_alert_description_e desc)
+{
+  return sln_io_alert(s, SLN_ALERT_LEVEL_FATAL, desc);
+}
+
+selene_error_t *
+sln_io_alert_warning(selene_t *s, sln_alert_description_e desc)
+{
+  return sln_io_alert(s, SLN_ALERT_LEVEL_WARNING, desc);
+}

lib/backends/native/alert_messages.h

@@ -59,4 +59,10 @@ typedef struct sln_msg_alert_t {
 selene_error_t*
 sln_alert_unparse(sln_msg_alert_t *alert, sln_bucket_t **p_b);
 
+selene_error_t*
+sln_io_alert_fatal(selene_t *s, sln_alert_description_e desc);
+
+selene_error_t*
+sln_io_alert_warning(selene_t *s, sln_alert_description_e desc);
+
 #endif

lib/backends/native/tls_io.c

@@ -17,6 +17,7 @@
 
 #include "native.h"
 #include "sln_tok.h"
+#include "alert_messages.h"
 #include <string.h>
 #include <stdio.h>
 
@@ -171,7 +172,8 @@ sln_native_io_tls_read(selene_t *s, sln_native_baton_t *baton)
   err = sln_tok_parser(s->bb.in_enc, read_tls, &rtls);
 
   if (err) {
-    /* TODO: send alert message, abort connection? */
+    /* TODO: logging here? */
+    sln_io_alert_fatal(s, SLN_ALERT_DESC_INTERNAL_ERROR);
     return err;
   }