From: Eelco Chaudron echaudro@redhat.com
[ Upstream commit 69929d4c49e182f8526d42c43b37b460d562d3a0 ]
Currently, the openvswitch module is not accepting the correctly formated netlink message for the TTL decrement action. For both setting and getting the dec_ttl action, the actions should be nested in the OVS_DEC_TTL_ATTR_ACTION attribute as mentioned in the openvswitch.h uapi.
When the original patch was sent, it was tested with a private OVS userspace implementation. This implementation was unfortunately not upstreamed and reviewed, hence an erroneous version of this patch was sent out.
Leaving the patch as-is would cause problems as the kernel module could interpret additional attributes as actions and vice-versa, due to the actions not being encapsulated/nested within the actual attribute, but being concatinated after it.
Fixes: 744676e77720 ("openvswitch: add TTL decrement action") Signed-off-by: Eelco Chaudron echaudro@redhat.com Link: https://lore.kernel.org/r/160622121495.27296.888010441924340582.stgit@wsfd-n... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/uapi/linux/openvswitch.h | 2 + net/openvswitch/actions.c | 7 +-- net/openvswitch/flow_netlink.c | 74 ++++++++++++++++++++++++++++----------- 3 files changed, 60 insertions(+), 23 deletions(-)
--- a/include/uapi/linux/openvswitch.h +++ b/include/uapi/linux/openvswitch.h @@ -1058,4 +1058,6 @@ enum ovs_dec_ttl_attr { __OVS_DEC_TTL_ATTR_MAX };
+#define OVS_DEC_TTL_ATTR_MAX (__OVS_DEC_TTL_ATTR_MAX - 1) + #endif /* _LINUX_OPENVSWITCH_H */ --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -970,14 +970,13 @@ static int dec_ttl_exception_handler(str { /* The first action is always 'OVS_DEC_TTL_ATTR_ARG'. */ struct nlattr *dec_ttl_arg = nla_data(attr); - int rem = nla_len(attr);
if (nla_len(dec_ttl_arg)) { - struct nlattr *actions = nla_next(dec_ttl_arg, &rem); + struct nlattr *actions = nla_data(dec_ttl_arg);
if (actions) - return clone_execute(dp, skb, key, 0, actions, rem, - last, false); + return clone_execute(dp, skb, key, 0, nla_data(actions), + nla_len(actions), last, false); } consume_skb(skb); return 0; --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -2503,28 +2503,42 @@ static int validate_and_copy_dec_ttl(str __be16 eth_type, __be16 vlan_tci, u32 mpls_label_count, bool log) { - int start, err; - u32 nested = true; + const struct nlattr *attrs[OVS_DEC_TTL_ATTR_MAX + 1]; + int start, action_start, err, rem; + const struct nlattr *a, *actions; + + memset(attrs, 0, sizeof(attrs)); + nla_for_each_nested(a, attr, rem) { + int type = nla_type(a); + + /* Ignore unknown attributes to be future proof. */ + if (type > OVS_DEC_TTL_ATTR_MAX) + continue;
- if (!nla_len(attr)) - return ovs_nla_add_action(sfa, OVS_ACTION_ATTR_DEC_TTL, - NULL, 0, log); + if (!type || attrs[type]) + return -EINVAL; + + attrs[type] = a; + } + + actions = attrs[OVS_DEC_TTL_ATTR_ACTION]; + if (rem || !actions || (nla_len(actions) && nla_len(actions) < NLA_HDRLEN)) + return -EINVAL;
start = add_nested_action_start(sfa, OVS_ACTION_ATTR_DEC_TTL, log); if (start < 0) return start;
- err = ovs_nla_add_action(sfa, OVS_DEC_TTL_ATTR_ACTION, &nested, - sizeof(nested), log); - - if (err) - return err; + action_start = add_nested_action_start(sfa, OVS_DEC_TTL_ATTR_ACTION, log); + if (action_start < 0) + return start;
- err = __ovs_nla_copy_actions(net, attr, key, sfa, eth_type, + err = __ovs_nla_copy_actions(net, actions, key, sfa, eth_type, vlan_tci, mpls_label_count, log); if (err) return err;
+ add_nested_action_end(*sfa, action_start); add_nested_action_end(*sfa, start); return 0; } @@ -3487,20 +3501,42 @@ out: static int dec_ttl_action_to_attr(const struct nlattr *attr, struct sk_buff *skb) { - int err = 0, rem = nla_len(attr); - struct nlattr *start; + struct nlattr *start, *action_start; + const struct nlattr *a; + int err = 0, rem;
start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_DEC_TTL); - if (!start) return -EMSGSIZE;
- err = ovs_nla_put_actions(nla_data(attr), rem, skb); - if (err) - nla_nest_cancel(skb, start); - else - nla_nest_end(skb, start); + nla_for_each_attr(a, nla_data(attr), nla_len(attr), rem) { + switch (nla_type(a)) { + case OVS_DEC_TTL_ATTR_ACTION: + + action_start = nla_nest_start_noflag(skb, OVS_DEC_TTL_ATTR_ACTION); + if (!action_start) { + err = -EMSGSIZE; + goto out; + }
+ err = ovs_nla_put_actions(nla_data(a), nla_len(a), skb); + if (err) + goto out; + + nla_nest_end(skb, action_start); + break; + + default: + /* Ignore all other option to be future compatible */ + break; + } + } + + nla_nest_end(skb, start); + return 0; + +out: + nla_nest_cancel(skb, start); return err; }