resolve: fix error handling of SSL_shutdown()

diff --git a/src/resolve/resolved-dnstls-openssl.c b/src/resolve/resolved-dnstls-openssl.c
index 6b765b58ecb8d52bb390ef17c6904b363d186213..c23211404b942bcb14529b39e0d2f2e470c63b8f 100644 (file)
--- a/src/resolve/resolved-dnstls-openssl.c
+++ b/src/resolve/resolved-dnstls-openssl.c
@@ -120,31 +120,42 @@ int dnstls_stream_on_io(DnsStream *stream, uint32_t revents) {
         if (stream->dnstls_data.shutdown) {
                 ERR_clear_error();
                 r = SSL_shutdown(stream->dnstls_data.ssl);
-                if (r <= 0) {
+                if (r == 0) {
+                        stream->dnstls_events = 0;
+
+                        r = dnstls_flush_write_buffer(stream);
+                        if (r < 0)
+                                return r;
+
+                        return -EAGAIN;
+                } else if (r < 0) {
                         error = SSL_get_error(stream->dnstls_data.ssl, r);
-                        if (r == 0 || IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) {
-                                if (r < 0)
-                                        stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT;
+                        if (IN_SET(error, SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE)) {
+                                stream->dnstls_events = error == SSL_ERROR_WANT_READ ? EPOLLIN : EPOLLOUT;
 
                                 r = dnstls_flush_write_buffer(stream);
                                 if (r < 0)
                                         return r;
 
                                 return -EAGAIN;
+                        } else if (error == SSL_ERROR_SYSCALL) {
+                                if (errno > 0)
+                                        log_debug_errno(errno, "Failed to invoke SSL_shutdown, ignoring: %m");
                         } else {
                                 char errbuf[256];
 
                                 ERR_error_string_n(error, errbuf, sizeof(errbuf));
-                                log_debug("Failed to invoke SSL_shutdown: %s", errbuf);
+                                log_debug("Failed to invoke SSL_shutdown, ignoring: %s", errbuf);
                         }
                 }
 
+                stream->dnstls_events = 0;
+                stream->dnstls_data.shutdown = false;
+
                 r = dnstls_flush_write_buffer(stream);
                 if (r < 0)
                         return r;
 
-                stream->dnstls_events = 0;
-                stream->dnstls_data.shutdown = false;
                 dns_stream_unref(stream);
                 return DNSTLS_STREAM_CLOSED;
         } else if (stream->dnstls_data.handshake <= 0) {
@@ -204,6 +215,8 @@ int dnstls_stream_shutdown(DnsStream *stream, int error) {
                                 dns_stream_ref(stream);
                         }
 
+                        stream->dnstls_events = 0;
+
                         r = dnstls_flush_write_buffer(stream);
                         if (r < 0)
                                 return r;
@@ -222,11 +235,14 @@ int dnstls_stream_shutdown(DnsStream *stream, int error) {
                                         dns_stream_ref(stream);
                                 }
                                 return -EAGAIN;
+                        } else if (ssl_error == SSL_ERROR_SYSCALL) {
+                                if (errno > 0)
+                                        log_debug_errno(errno, "Failed to invoke SSL_shutdown, ignoring: %m");
                         } else {
                                 char errbuf[256];
 
                                 ERR_error_string_n(ssl_error, errbuf, sizeof(errbuf));
-                                log_debug("Failed to invoke SSL_shutdown: %s", errbuf);
+                                log_debug("Failed to invoke SSL_shutdown, ignoring: %s", errbuf);
                         }
                 }