In documentation, consistently refer to OpenSSL 3.0

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

diff --git a/doc/man3/SSL_write.pod b/doc/man3/SSL_write.pod
index 2a751107bb95af8ce38d64d2cb2586234554bf7c..04cc46b27a5c3b7ec5f0bb8e1262de867d87f0f5 100644 (file)
--- a/doc/man3/SSL_write.pod
+++ b/doc/man3/SSL_write.pod
@@ -2,12 +2,13 @@
 
 =head1 NAME
 
-SSL_write_ex, SSL_write - write bytes to a TLS/SSL connection
+SSL_write_ex, SSL_write, SSL_sendfile - write bytes to a TLS/SSL connection
 
 =head1 SYNOPSIS
 
  #include <openssl/ssl.h>
 
+ ossl_ssize_t SSL_sendfile(SSL *s, int fd, off_t offset, size_t size, int flags);
  int SSL_write_ex(SSL *s, const void *buf, size_t num, size_t *written);
  int SSL_write(SSL *ssl, const void *buf, int num);
 
@@ -17,6 +18,14 @@ SSL_write_ex() and SSL_write() write B<num> bytes from the buffer B<buf> into
 the specified B<ssl> connection. On success SSL_write_ex() will store the number
 of bytes written in B<*written>.
 
+SSL_sendfile() writes B<size> bytes from offset B<offset> in the file
+descriptor B<fd> to the specified SSL connection B<s>. This function provides
+efficient zero-copy semantics. SSL_sendfile() is available only when
+Kernel TLS is enabled, which can be checked by calling BIO_get_ktls_send().
+It is provided here to allow users to maintain the same interface.
+The meaning of B<flags> is platform dependent.
+Currently, under Linux it is ignored.
+
 =head1 NOTES
 
 In the paragraphs below a "write function" is defined as one of either
@@ -25,7 +34,7 @@ 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 +43,7 @@ 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 +71,13 @@ 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
 
@@ -103,19 +113,41 @@ You should instead call SSL_get_error() to find out if it's retryable.
 
 =back
 
+For SSL_sendfile(), the following return values can occur:
+
+=over 4
+
+=item Z<>>= 0
+
+The write operation was successful, the return value is the number
+of bytes of the file written to the TLS/SSL connection.
+
+=item E<lt> 0
+
+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 to find out the reason.
+
+=back
+
 =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_set_connect_state(3)>, L<BIO_ctrl(3)>,
 L<ssl(7)>, L<bio(7)>
 
+=head1 HISTORY
+
+The SSL_write_ex() function was added in OpenSSL 1.1.1.
+The SSL_sendfile() function was added in OpenSSL 3.0.
+
 =head1 COPYRIGHT
 
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
 
-Licensed under the OpenSSL license (the "License").  You may not use
+Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy
 in the file LICENSE in the source distribution or at
 L<https://www.openssl.org/source/license.html>.