Add a note about aborts encountered while sending early_data

[openssl.git] / doc / man3 / SSL_write.pod

diff --git a/doc/man3/SSL_write.pod b/doc/man3/SSL_write.pod
index c860ed7978188d3d747bb40dbf133c16618fe5ba..d52844281fc703b05569ff32189bc0048a578d0b 100644 (file)
--- a/doc/man3/SSL_write.pod
+++ b/doc/man3/SSL_write.pod
@@ -25,7 +25,7 @@ SSL_write_ex(), or SSL_write().
 If necessary, a write function will negotiate a TLS/SSL session, if not already
 explicitly performed by L<SSL_connect(3)> or L<SSL_accept(3)>. If the peer
 requests a re-negotiation, it will be performed transparently during
-the write functio operation. The behaviour of the write functions depends on the
+the write function operation. The behaviour of the write functions depends on the
 underlying BIO.
 
 For the transparent negotiation to succeed, the B<ssl> must have been
@@ -34,10 +34,7 @@ L<SSL_set_connect_state(3)> or SSL_set_accept_state()
 before the first call to a write function.
 
 If the underlying BIO is B<blocking>, the write functions will only return, once
-the write operation has been finished or an error occurred, except when a
-renegotiation take place, in which case a SSL_ERROR_WANT_READ may occur.
-This behaviour can be controlled with the SSL_MODE_AUTO_RETRY flag of the
-L<SSL_CTX_set_mode(3)> call.
+the write operation has been finished or an error occurred.
 
 If the underlying BIO is B<non-blocking> the write functions will also return
 when the underlying BIO could not satisfy the needs of the function to continue
@@ -65,9 +62,13 @@ write is performed with the size of a message block, which is 16kB.
 When a write function call has to be repeated because L<SSL_get_error(3)>
 returned B<SSL_ERROR_WANT_READ> or B<SSL_ERROR_WANT_WRITE>, it must be repeated
 with the same arguments.
+The data that was passed might have been partially processed.
+When B<SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER> was set using L<SSL_CTX_set_mode(3)>
+the pointer can be different, but the data and length should still be the same.
 
-When calling the write functions with num=0 bytes to be sent the behaviour is
-undefined.
+You should not call SSL_write() with num=0, it will return an error.
+SSL_write_ex() can be called with num=0, but will not send application data to
+the peer.
 
 =head1 RETURN VALUES
 
@@ -86,33 +87,34 @@ For SSL_write() the following return values can occur:
 
 =over 4
 
-=item E<gt>0
+=item E<gt> 0
 
 The write operation was successful, the return value is the number of
 bytes actually written to the TLS/SSL connection.
 
-=item Z<>0
+=item Z<><= 0
 
-The write operation was not successful. Probably 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).
+The write operation was not successful, because either the connection was
+closed, an error occurred or action must be taken by the calling process.
+Call SSL_get_error() with the return value B<ret> to find out the reason.
 
-=item E<lt>0
-
-The write operation was not successful, because either an error occurred
-or action must be taken by the calling process. Call SSL_get_error() with the
-return value B<ret> to find out the reason.
+Old documentation indicated a difference between 0 and -1, and that -1 was
+retryable.
+You should instead call SSL_get_error() to find out if it's retryable.
 
 =back
 
+=head1 HISTORY
+
+SSL_write_ex() was added in OpenSSL 1.1.1.
+
 =head1 SEE ALSO
 
 L<SSL_get_error(3)>, L<SSL_read_ex(3)>, L<SSL_read(3)>
 L<SSL_CTX_set_mode(3)>, L<SSL_CTX_new(3)>,
 L<SSL_connect(3)>, L<SSL_accept(3)>
 L<SSL_set_connect_state(3)>,
-L<ssl(3)>, L<bio(3)>
+L<ssl(7)>, L<bio(7)>
 
 =head1 COPYRIGHT