Update IPv6 related readme files

Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1388760580-7548-1-git-send-email-arne@rfc2549.org>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8167

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Make tls_ctx_restrict_ciphers accept NULL as char *cipher_list.

This adds some ifs to check for NULL in tls_ctx_restrict_ciphers() to
prepare
for disabling export ciphers by default in OpenVPN 2.4+.

Also let tls_ctx_restrict_ciphers always be called, also when *cipher_list
is
NULL.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <52C8922E.3030607@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8173
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Disable export ciphers by default for OpenSSL builds.

Export ciphers are deliberately weak ciphers, and not fully supported by
OpenVPN since ephemeral RSA support has been removed a few commits ago.
This commit removes them from the default cipher list to avoid confusion.

PolarSSL does not support export ciphers, so no action required there.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1388607026-12297-7-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8146
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Implement LZ4 compression.

Implement LZ4 compression, similar to the existing snappy / push-peer-info
model: a LZ4 capable client will send IV_LZ4=1 to the server, and the
algorithm is selected by pushing "compress lz4" back.

LZ4 does not compress as well as LZO or Snappy, but needs far less CPU
and is much faster, thus better suited for mobile devices.  See
https://code.google.com/p/lz4/ for more details.

LZ4 include and library path can be specified by specifying LZ4_LIBS=...
and LZ4_CFLAGS=... on the configure command line.

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1388613479-22377-1-git-send-email-gert@greenie.muc.de>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8153
Provide LZ4 sources in src/compat/ and use if no system lz4 library found.

Bundle lz4.c and lz4.h from http://code.google.com/p/lz4/ (r109) as
src/compat/compat-lz4.[ch], and use that (via #define NEED_COMPAT_LZ4)
if autoconf cannot find lz4.h or -llz4 in the system.

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1388613479-22377-2-git-send-email-gert@greenie.muc.de>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8154