Add BIO_bind function to bind local address for a socket.

Add -bind option to s_client application to allow specification of
local address for connection.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5272)

1 files changed, 10 insertions, 0 deletions

diff --git a/doc/man1/s_client.pod b/doc/man1/s_client.pod
index 8d8eac76f4..6e47140f41 100644
--- a/doc/man1/s_client.pod
+++ b/doc/man1/s_client.pod
@@ -10,6 +10,7 @@ s_client - SSL/TLS client program
 B<openssl> B<s_client>
 [B<-help>]
 [B<-connect host:port>]
+[B<-bind host:port>]
 [B<-proxy host:port>]
 [B<-unix path>]
 [B<-4>]
@@ -147,6 +148,12 @@ select the host and port using the optional target positional argument instead.
 If neither this nor the target positonal argument are specified then an attempt
 is made to connect to the local host on port 4433.
 
+=item B<-bind host:port>]
+
+This specifies the host address and or port to bind as the source for the
+connection.  For Unix-domain sockets the port is ignored and the host is
+used as the source socket address.
+
 =item B<-proxy host:port>
 
 When used with the B<-connect> flag, the program uses the host and port
@@ -686,6 +693,9 @@ applications should B<not> do this as it makes them vulnerable to a MITM
 attack. This behaviour can be changed by with the B<-verify_return_error>
 option: any verify errors are then returned aborting the handshake.
 
+The B<-bind> option may be useful if the server or a firewall requires
+connections to come from some particular address and or port.
+
 =head1 BUGS
 
 Because this program has a lot of options and also because some of the