* Add limit of maximum allowed smtp session errors

4 files changed, 27 insertions, 0 deletions

diff --git a/src/smtp.c b/src/smtp.c
index 7860f1ac5..c5abf5eec 100644
--- a/src/smtp.c
+++ b/src/smtp.c
@@ -175,6 +175,7 @@ read_smtp_command (struct smtp_session *session, f_str_t *line)
 	
 	if (! parse_smtp_command (session, line, &cmd)) {
 		session->error = SMTP_ERROR_BAD_COMMAND;
+		session->errors ++;
 		return FALSE;
 	}
 	
@@ -185,6 +186,9 @@ read_smtp_command (struct smtp_session *session, f_str_t *line)
 				if (parse_smtp_helo (session, cmd)) {
 					session->state = SMTP_STATE_FROM;
 				}
+				else {
+					session->errors ++;
+				}
 				return TRUE;
 			}
 			else {
@@ -203,6 +207,7 @@ read_smtp_command (struct smtp_session *session, f_str_t *line)
 					session->state = SMTP_STATE_RCPT;
 				}
 				else {
+					session->errors ++;
 					return FALSE;
 				}
 			}
@@ -235,6 +240,7 @@ read_smtp_command (struct smtp_session *session, f_str_t *line)
 					return TRUE;
 				}
 				else {
+					session->errors ++;
 					return FALSE;
 				}
 			}
@@ -257,6 +263,7 @@ read_smtp_command (struct smtp_session *session, f_str_t *line)
 			if (session->state == SMTP_STATE_RCPT) {
 				if (session->rcpt == NULL) {
 					session->error = SMTP_ERROR_RECIPIENTS;
+					session->errors ++;
 					return FALSE;
 				}
 				if (session->upstream == NULL) {
@@ -287,6 +294,7 @@ read_smtp_command (struct smtp_session *session, f_str_t *line)
 	return TRUE;
 
 improper_sequence:
+	session->errors ++;
 	session->error = SMTP_ERROR_SEQUENCE;
 	return FALSE;
 }
@@ -420,6 +428,13 @@ smtp_read_socket (f_str_t * in, void *arg)
 		case SMTP_STATE_DATA:
 			read_smtp_command (session, in);
 			if (session->state != SMTP_STATE_WAIT_UPSTREAM) {
+				if (session->errors > session->ctx->max_errors) {
+					session->error = SMTP_ERROR_LIMIT;
+					session->state = SMTP_STATE_CRITICAL_ERROR;
+					rspamd_dispatcher_write (session->dispatcher, session->error, 0, FALSE, TRUE);
+					destroy_session (session->s);
+					return FALSE;
+				}
 				smtp_write_socket (session);
 			}
 			break;
@@ -987,6 +1002,12 @@ config_smtp_worker (struct rspamd_worker *worker)
 	else {
 		ctx->metric = DEFAULT_METRIC;
 	}
+	if ((value = g_hash_table_lookup (worker->cf->params, "smtp_max_errors")) != NULL) {
+		ctx->max_errors = strtoul (value, NULL, 10);
+	}
+	else {
+		ctx->max_errors = DEFAULT_MAX_ERRORS;
+	}
 	if ((value = g_hash_table_lookup (worker->cf->params, "smtp_reject_message")) != NULL) {
 		ctx->reject_message = memory_pool_strdup (ctx->pool, value);
 	}
diff --git a/src/smtp.h b/src/smtp.h
index 83d89c5aa..11062543d 100644
--- a/src/smtp.h
+++ b/src/smtp.h
@@ -15,6 +15,7 @@ struct smtp_upstream {
 }; 
 
 #define MAX_UPSTREAM 128
+#define DEFAULT_MAX_ERRORS 10
 
 struct smtp_worker_ctx {
 	struct smtp_upstream upstreams[MAX_UPSTREAM];
@@ -31,6 +32,7 @@ struct smtp_worker_ctx {
 	char *smtp_capabilities;
 	char *reject_message;
 	size_t max_size;
+	guint max_errors;
 	char *metric;
 };
 
@@ -76,6 +78,8 @@ struct smtp_session {
 	GList *from;
 	GList *rcpt;
 	GList *cur_rcpt;
+
+	guint errors;
 	
 	struct rspamd_async_session *s;
 	rspamd_io_dispatcher_t *dispatcher;
diff --git a/src/smtp_proto.c b/src/smtp_proto.c
index b80573276..e372cec55 100644
--- a/src/smtp_proto.c
+++ b/src/smtp_proto.c
@@ -511,6 +511,7 @@ smtp_upstream_read_socket (f_str_t * in, void *arg)
 				else {
 					session->rcpt = g_list_delete_link (session->rcpt, session->rcpt);
 				}
+				session->errors ++;
 				session->state = SMTP_STATE_RCPT;
 				return TRUE;
 			}
diff --git a/src/smtp_proto.h b/src/smtp_proto.h
index f451f3abf..d44cbe7b1 100644
--- a/src/smtp_proto.h
+++ b/src/smtp_proto.h
@@ -10,6 +10,7 @@
 #define SMTP_ERROR_SEQUENCE "503 Bad sequence of commands" CRLF
 #define SMTP_ERROR_RECIPIENTS "554 No valid recipients" CRLF
 #define SMTP_ERROR_UNIMPLIMENTED "502 Command not implemented" CRLF
+#define SMTP_ERROR_LIMIT "505 Too many errors. Aborting." CRLF
 #define SMTP_ERROR_UPSTREAM "421 Service not available, closing transmission channel" CRLF
 #define SMTP_ERROR_FILE "420 Service not available, filesystem error" CRLF
 #define SMTP_ERROR_OK "250 Requested mail action okay, completed" CRLF