From 6f1326d6b68f6dcb83843374c876407ef2922bd1 Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Mon, 14 Feb 2022 19:07:29 +0100 Subject: tunnel: T4154: verify() no more then one GRE tunnel is used w/o "ip key" per interface It is impossible for the OS kernel to distinguish multiple GRE tunnels when no "gre key" is configured when sourcing tunnels from the same interface. --- src/conf_mode/interfaces-tunnel.py | 39 +++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-) diff --git a/src/conf_mode/interfaces-tunnel.py b/src/conf_mode/interfaces-tunnel.py index 30f57ec0c..c9267e749 100755 --- a/src/conf_mode/interfaces-tunnel.py +++ b/src/conf_mode/interfaces-tunnel.py @@ -103,19 +103,22 @@ def verify(tunnel): raise ConfigError('Tunnel parameters ip key must be set!') if tunnel['encapsulation'] in ['gre', 'gretap']: - if dict_search('parameters.ip.key', tunnel) != None: - # Check pairs tunnel source-address/encapsulation/key with exists tunnels. - # Prevent the same key for 2 tunnels with same source-address/encap. T2920 - for tunnel_if in Section.interfaces('tunnel'): - # It makes no sense to run the test for re-used GRE keys on our - # own interface we are currently working on - if tunnel['ifname'] == tunnel_if: - continue - tunnel_cfg = get_interface_config(tunnel_if) - # no match on encapsulation - bail out - if dict_search('linkinfo.info_kind', tunnel_cfg) != tunnel['encapsulation']: - continue - new_source_address = dict_search('source_address', tunnel) + # Check pairs tunnel source-address/encapsulation/key with exists tunnels. + # Prevent the same key for 2 tunnels with same source-address/encap. T2920 + for tunnel_if in Section.interfaces('tunnel'): + # It makes no sense to run the test against our own interface we + # are currently configuring + if tunnel['ifname'] == tunnel_if: + continue + + tunnel_cfg = get_interface_config(tunnel_if) + # no match on encapsulation - bail out + if dict_search('linkinfo.info_kind', tunnel_cfg) != tunnel['encapsulation']: + continue + + new_source_address = dict_search('source_address', tunnel) + new_source_interface = dict_search('source_interface', tunnel) + if dict_search('parameters.ip.key', tunnel) != None: # Convert tunnel key to ip key, format "ip -j link show" # 1 => 0.0.0.1, 999 => 0.0.3.231 orig_new_key = dict_search('parameters.ip.key', tunnel) @@ -125,6 +128,16 @@ def verify(tunnel): dict_search('linkinfo.info_data.ikey', tunnel_cfg) == new_key: raise ConfigError(f'Key "{orig_new_key}" for source-address "{new_source_address}" ' \ f'is already used for tunnel "{tunnel_if}"!') + else: + # If no IP GRE key is used we can not have more then one GRE tunnel + # bound to any one interface/IP address. This will result in a OS + # PermissionError: add tunnel "gre0" failed: File exists + if (dict_search('address', tunnel_cfg) == new_source_address or + (dict_search('address', tunnel_cfg) == '0.0.0.0' and + dict_search('link', tunnel_cfg) == new_source_interface)): + raise ConfigError(f'Missing required "ip key" parameter when \ + running more then one GRE based tunnel on the \ + same source-interface/source-address') # Keys are not allowed with ipip and sit tunnels if tunnel['encapsulation'] in ['ipip', 'sit']: -- cgit v1.2.3