diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-02-10 12:08:17 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-02-12 14:45:11 +0100 |
| commit | 8c4d4e8b5626fec965fd5034e5bd5e57790f243f (patch) | |
| tree | e8ce0acf10108f74d0ce8cd150f061baff0686bf /include | |
| parent | 48656835c0405aa2e6c0d6a4305c77b70758d168 (diff) | |
netfilter: nfnetlink: allow to check for generation ID
This patch allows userspace to specify the generation ID that has been
used to build an incremental batch update.
If userspace specifies the generation ID in the batch message as
attribute, then nfnetlink compares it to the current generation ID so
you make sure that you work against the right baseline. Otherwise, bail
out with ERESTART so userspace knows that its changeset is stale and
needs to respin. Userspace can do this transparently at the cost of
taking slightly more time to refresh caches and rework the changeset.
This check is optional, if there is no NFNL_BATCH_GENID attribute in the
batch begin message, then no check is performed.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netfilter/nfnetlink.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/netfilter/nfnetlink.h | 12 |
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h index 1d82dd5e9a08..1b49209dd5c7 100644 --- a/include/linux/netfilter/nfnetlink.h +++ b/include/linux/netfilter/nfnetlink.h @@ -28,6 +28,7 @@ struct nfnetlink_subsystem { const struct nfnl_callback *cb; /* callback for individual types */ int (*commit)(struct net *net, struct sk_buff *skb); int (*abort)(struct net *net, struct sk_buff *skb); + bool (*valid_genid)(struct net *net, u32 genid); }; int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n); diff --git a/include/uapi/linux/netfilter/nfnetlink.h b/include/uapi/linux/netfilter/nfnetlink.h index 4bb8cb7730e7..a09906a30d77 100644 --- a/include/uapi/linux/netfilter/nfnetlink.h +++ b/include/uapi/linux/netfilter/nfnetlink.h @@ -65,4 +65,16 @@ struct nfgenmsg { #define NFNL_MSG_BATCH_BEGIN NLMSG_MIN_TYPE #define NFNL_MSG_BATCH_END NLMSG_MIN_TYPE+1 +/** + * enum nfnl_batch_attributes - nfnetlink batch netlink attributes + * + * @NFNL_BATCH_GENID: generation ID for this changeset (NLA_U32) + */ +enum nfnl_batch_attributes { + NFNL_BATCH_UNSPEC, + NFNL_BATCH_GENID, + __NFNL_BATCH_MAX +}; +#define NFNL_BATCH_MAX (__NFNL_BATCH_MAX - 1) + #endif /* _UAPI_NFNETLINK_H */ |