From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Tue, 2 Mar 2021 13:15:09 +0000 (+0200)
Subject: lib-smtp: Standardize iostream error handling
X-Git-Tag: 2.3.15~262
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5e34090a35cfeff373b18bce33a72bf4332d289a;p=thirdparty%2Fdovecot%2Fcore.git

lib-smtp: Standardize iostream error handling

Use [io]_stream_get_disconnect_reason() for logging all errors.
None of the iostream errors are logged as error level anymore. This way
for example TLS connection problems caused by broken clients aren't
logged as errors.
---

diff --git a/src/lib-smtp/smtp-command-parser.c b/src/lib-smtp/smtp-command-parser.c
index e3a321d5b5..32a53cc2ac 100644
--- a/src/lib-smtp/smtp-command-parser.c
+++ b/src/lib-smtp/smtp-command-parser.c
@@ -387,8 +387,7 @@ static int smtp_command_parse(struct smtp_command_parser *parser)
 		} else {
 			smtp_command_parser_error(
 				parser, SMTP_COMMAND_PARSE_ERROR_BROKEN_STREAM,
-				"Stream error: %s",
-				i_stream_get_error(parser->input));
+				"%s", i_stream_get_disconnect_reason(parser->input));
 		}
 	}
 	return ret;
@@ -431,8 +430,7 @@ static int smtp_command_parse_finish_data(struct smtp_command_parser *parser)
 		default:
 			smtp_command_parser_error(
 				parser, SMTP_COMMAND_PARSE_ERROR_BROKEN_STREAM,
-				"Stream error while skipping command data: "
-				"%s", i_stream_get_error(parser->data));
+				"%s", i_stream_get_disconnect_reason(parser->data));
 		}
 		return -1;
 	}
diff --git a/src/lib-smtp/smtp-server-cmd-auth.c b/src/lib-smtp/smtp-server-cmd-auth.c
index 616b9c040b..841e1866b2 100644
--- a/src/lib-smtp/smtp-server-cmd-auth.c
+++ b/src/lib-smtp/smtp-server-cmd-auth.c
@@ -76,22 +76,8 @@ static void cmd_auth_input(struct smtp_server_cmd_ctx *cmd)
 		&auth_response, &error_code, &error)) <= 0) {
 		/* check for disconnect */
 		if (conn->conn.input->eof) {
-			switch (conn->conn.input->stream_errno) {
-			case 0:
-			case EPIPE:
-			case ECONNRESET:
-				smtp_server_connection_close(&conn,
-					"Remote closed connection unexpectedly during AUTH");
-				break;
-			default:
-				e_error(conn->event,
-					"Connection lost during AUTH: "
-					"read(%s) failed: %s",
-					i_stream_get_name(conn->conn.input),
-					i_stream_get_error(conn->conn.input));
-				smtp_server_connection_close(&conn,
-					"Read failure");
-			}
+			smtp_server_connection_close(&conn,
+				i_stream_get_disconnect_reason(conn->conn.input));
 			return;
 		}
 		/* handle syntax error */
diff --git a/src/lib-smtp/smtp-server-cmd-data.c b/src/lib-smtp/smtp-server-cmd-data.c
index 1979a5001e..572b52dee9 100644
--- a/src/lib-smtp/smtp-server-cmd-data.c
+++ b/src/lib-smtp/smtp-server-cmd-data.c
@@ -244,7 +244,7 @@ static void cmd_data_input_error(struct smtp_server_cmd_ctx *cmd)
 	struct smtp_server_command *command = cmd->cmd;
 	struct cmd_data_context *data_cmd = command->data;
 	struct istream *data_input = conn->state.data_input;
-	unsigned int stream_errno = data_input->stream_errno;
+	const char *error;
 
 	conn->state.data_failed = TRUE;
 
@@ -256,18 +256,9 @@ static void cmd_data_input_error(struct smtp_server_cmd_ctx *cmd)
 		return;
 	}
 
-	if (stream_errno != EPIPE && stream_errno != ECONNRESET) {
-		e_error(conn->event, "Connection lost during data transfer: "
-			"read(%s) failed: %s",
-			i_stream_get_name(data_input),
-			i_stream_get_error(data_input));
-		smtp_server_connection_close(&conn, "Read failure");
-	} else {
-		e_debug(conn->event, "Connection lost during data transfer: "
-			"Remote disconnected");
-		smtp_server_connection_close(&conn,
-			"Remote closed connection unexpectedly");
-	}
+	error = i_stream_get_disconnect_reason(data_input);
+	e_debug(conn->event, "Connection lost during data transfer: %s", error);
+	smtp_server_connection_close(&conn, error);
 }
 
 static int cmd_data_do_handle_input(struct smtp_server_cmd_ctx *cmd)
diff --git a/src/lib-smtp/smtp-server-connection.c b/src/lib-smtp/smtp-server-connection.c
index c462238f5a..5d3af14054 100644
--- a/src/lib-smtp/smtp-server-connection.c
+++ b/src/lib-smtp/smtp-server-connection.c
@@ -483,32 +483,22 @@ smtp_server_connection_handle_input(struct smtp_server_connection *conn)
 		}
 
 		if (ret < 0 && conn->conn.input->eof) {
-			int stream_errno = conn->conn.input->stream_errno;
-			if (stream_errno != 0 && stream_errno != EPIPE &&
-			    stream_errno != ECONNRESET) {
-				e_error(conn->event,
-					"Connection lost: read(%s) failed: %s",
-					i_stream_get_name(conn->conn.input),
-					i_stream_get_error(conn->conn.input));
-				smtp_server_connection_close(&conn,
-					"Read failure");
+			const char *error =
+				i_stream_get_disconnect_reason(conn->conn.input);
+			e_debug(conn->event, "Remote closed connection: %s",
+				error);
+
+			if (conn->command_queue_head == NULL ||
+			    conn->command_queue_head->state <
+			    SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY) {
+				/* No pending commands or unfinished
+				   command; close */
+				smtp_server_connection_close(&conn, error);
 			} else {
-				e_debug(conn->event,
-					"Connection lost: Remote disconnected");
-
-				if (conn->command_queue_head == NULL ||
-				    conn->command_queue_head->state <
-					SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY) {
-					/* No pending commands or unfinished
-					   command; close */
-					smtp_server_connection_close(&conn,
-						"Remote closed connection");
-				} else {
-					/* A command is still processing;
-					   only drop input io for now */
-					conn->input_broken = TRUE;
-					smtp_server_connection_input_halt(conn);
-				}
+				/* A command is still processing;
+				   only drop input io for now */
+				conn->input_broken = TRUE;
+				smtp_server_connection_input_halt(conn);
 			}
 			return;
 		}
@@ -544,8 +534,7 @@ smtp_server_connection_handle_input(struct smtp_server_connection *conn)
 					"Command data size exceeds absolute limit");
 				return;
 			case SMTP_COMMAND_PARSE_ERROR_BROKEN_STREAM:
-				smtp_server_connection_close(&conn,
-					"Command data ended prematurely");
+				smtp_server_connection_close(&conn, error);
 				return;
 			default:
 				i_unreached();
@@ -627,18 +616,8 @@ bool smtp_server_connection_pending_command_data(
 void smtp_server_connection_handle_output_error(
 	struct smtp_server_connection *conn)
 {
-	struct ostream *output = conn->conn.output;
-
-	if (output->stream_errno != EPIPE &&
-	    output->stream_errno != ECONNRESET) {
-		e_error(conn->event, "Connection lost: write(%s) failed: %s",
-			o_stream_get_name(output), o_stream_get_error(output));
-		smtp_server_connection_close(&conn, "Write failure");
-	} else {
-		e_debug(conn->event, "Connection lost: Remote disconnected");
-		smtp_server_connection_close(
-			&conn, "Remote closed connection unexpectedly");
-	}
+	smtp_server_connection_close(&conn,
+		o_stream_get_disconnect_reason(conn->conn.output));
 }
 
 static bool