1 files changed, 77 insertions, 0 deletions
diff --git a/doc/ssl/SSL_want.pod b/doc/ssl/SSL_want.pod
new file mode 100644
index 000000000000..c0059c0d4a56
--- /dev/null
+++ b/doc/ssl/SSL_want.pod
@@ -0,0 +1,77 @@
+=pod
+
+=head1 NAME
+
+SSL_want, SSL_want_nothing, SSL_want_read, SSL_want_write, SSL_want_x509_lookup - obtain state information TLS/SSL I/O operation
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ int SSL_want(const SSL *ssl);
+ int SSL_want_nothing(const SSL *ssl);
+ int SSL_want_read(const SSL *ssl);
+ int SSL_want_write(const SSL *ssl);
+ int SSL_want_x509_lookup(const SSL *ssl);
+
+=head1 DESCRIPTION
+
+SSL_want() returns state information for the SSL object B<ssl>.
+
+The other SSL_want_*() calls are shortcuts for the possible states returned
+by SSL_want().
+
+=head1 NOTES
+
+SSL_want() examines the internal state information of the SSL object. Its
+return values are similar to that of L<SSL_get_error(3)|SSL_get_error(3)>.
+Unlike L<SSL_get_error(3)|SSL_get_error(3)>, which also evaluates the
+error queue, the results are obtained by examining an internal state flag
+only. The information must therefore only be used for normal operation under
+non-blocking I/O. Error conditions are not handled and must be treated
+using L<SSL_get_error(3)|SSL_get_error(3)>.
+
+The result returned by SSL_want() should always be consistent with
+the result of L<SSL_get_error(3)|SSL_get_error(3)>.
+
+=head1 RETURN VALUES
+
+The following return values can currently occur for SSL_want():
+
+=over 4
+
+=item SSL_NOTHING
+
+There is no data to be written or to be read.
+
+=item SSL_WRITING
+
+There are data in the SSL buffer that must be written to the underlying
+B<BIO> layer in order to complete the actual SSL_*() operation.
+A call to L<SSL_get_error(3)|SSL_get_error(3)> should return
+SSL_ERROR_WANT_WRITE.
+
+=item SSL_READING
+
+More data must be read from the underlying B<BIO> layer in order to
+complete the actual SSL_*() operation.
+A call to L<SSL_get_error(3)|SSL_get_error(3)> should return
+SSL_ERROR_WANT_READ.
+
+=item SSL_X509_LOOKUP
+
+The operation did not complete because an application callback set by
+SSL_CTX_set_client_cert_cb() has asked to be called again.
+A call to L<SSL_get_error(3)|SSL_get_error(3)> should return
+SSL_ERROR_WANT_X509_LOOKUP.
+
+=back
+
+SSL_want_nothing(), SSL_want_read(), SSL_want_write(), SSL_want_x509_lookup()
+return 1, when the corresponding condition is true or 0 otherwise.
+
+=head1 SEE ALSO
+
+L<ssl(3)|ssl(3)>, L<err(3)|err(3)>, L<SSL_get_error(3)|SSL_get_error(3)>
+
+=cut