More interdependencies with respect to shutdown behaviour.

[openssl.git] / doc / ssl / SSL_write.pod

diff --git a/doc/ssl/SSL_write.pod b/doc/ssl/SSL_write.pod
index da66f0f056fc2be2e63b90e7dfea8fc498a2ced1..7299f6e2ee28f9f96e36498cfa1d1aaa455149af 100644 (file)
--- a/doc/ssl/SSL_write.pod
+++ b/doc/ssl/SSL_write.pod
@@ -78,8 +78,18 @@ bytes actually written to the TLS/SSL connection.
 
 =item 0
 
-The write operation was not successful. Call SSL_get_error() with the return
-value B<ret> to find out, whether an error occurred.
+The write operation was not successful, because the write side of the
+SSL connection was shut down (the SSL_SENT_SHUTDOWN flag in the shutdown
+state is set) by calling L<SSL_shutdown(3)|SSL_shutdown(3)> or
+L<SSL_set_shutdown(3)|SSL_set_shutdown(3)>. It is also possible, that the
+underlying connection was closed.
+Call SSL_get_error() with the return value B<ret> to find out,
+whether an error occurred or the connection was shut down cleanly
+(SSL_ERROR_ZERO_RETURN).
+
+SSLv2 (deprecated) does not support a shutdown alert protocol, so it can
+only be detected, whether the underlying connection was closed. It cannot
+be checked, why the closure happened.
 
 =item E<lt>0