[PATCH 17/29] netfilter: nf_tables: reject hook configuration updates on existing chains
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STALE3697d
SUPERSEDED
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2016-09-05 10:59:14
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v1 of 44 in this series.
Revisions (44)
Currently, if you add a base chain whose name clashes with an existing
non-base chain, nf_tables doesn't complain about this. Similarly, if you
update the chain type, the hook number and priority.
With this patch, nf_tables bails out in case any of this unsupported
operations occur by returning EBUSY.
# nft add table x
# nft add chain x y
# nft add chain x y { type nat hook input priority 0\; }
<cmdline>:1:1-49: Error: Could not process rule: Device or resource busy
add chain x y { type nat hook input priority 0; }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_tables_api.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 463fcad..221d27f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c@@ -1348,6 +1348,37 @@ static int nf_tables_newchain(struct net *net, struct sock *nlsk, if (nlh->nlmsg_flags & NLM_F_REPLACE) return -EOPNOTSUPP; + if (nla[NFTA_CHAIN_HOOK]) { + struct nft_base_chain *basechain; + struct nft_chain_hook hook; + struct nf_hook_ops *ops; + + if (!(chain->flags & NFT_BASE_CHAIN)) + return -EBUSY; + + err = nft_chain_parse_hook(net, nla, afi, &hook, + create); + if (err < 0) + return err; + + basechain = nft_base_chain(chain); + if (basechain->type != hook.type) { + nft_chain_release_hook(&hook); + return -EBUSY; + } + + for (i = 0; i < afi->nops; i++) { + ops = &basechain->ops[i]; + if (ops->hooknum != hook.num || + ops->priority != hook.priority || + ops->dev != hook.dev) { + nft_chain_release_hook(&hook); + return -EBUSY; + } + } + nft_chain_release_hook(&hook); + } + if (nla[NFTA_CHAIN_HANDLE] && name) { struct nft_chain *chain2;
--
2.1.4