netfilter: nf_tables: extend tracing infrastructure
nft monitor mode can then decode and display this trace data.
Parts of LL/Network/Transport headers are provided as separate
attributes.
Otherwise, printing IP address data becomes virtually impossible
for userspace since in the case of the netdev family we really don't
want userspace to have to know all the possible link layer types
and/or sizes just to display/print an ip address.
We also don't want userspace to have to follow ipv6 header chains
to get the s/dport info, the kernel already did this work for us.
To avoid bloating nft_do_chain all data required for tracing is
encapsulated in nft_traceinfo.
The structure is initialized unconditionally(!) for each nft_do_chain
invocation.
This unconditionall call will be moved under a static key in a
followup patch.
With lots of help from Patrick McHardy and Pablo Neira.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 5f3ecec..b48a3ab 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -83,6 +83,7 @@
* @NFT_MSG_DELSETELEM: delete a set element (enum nft_set_elem_attributes)
* @NFT_MSG_NEWGEN: announce a new generation, only for events (enum nft_gen_attributes)
* @NFT_MSG_GETGEN: get the rule-set generation (enum nft_gen_attributes)
+ * @NFT_MSG_TRACE: trace event (enum nft_trace_attributes)
*/
enum nf_tables_msg_types {
NFT_MSG_NEWTABLE,
@@ -102,6 +103,7 @@
NFT_MSG_DELSETELEM,
NFT_MSG_NEWGEN,
NFT_MSG_GETGEN,
+ NFT_MSG_TRACE,
NFT_MSG_MAX,
};
@@ -987,4 +989,54 @@
};
#define NFTA_GEN_MAX (__NFTA_GEN_MAX - 1)
+/**
+ * enum nft_trace_attributes - nf_tables trace netlink attributes
+ *
+ * @NFTA_TRACE_TABLE: name of the table (NLA_STRING)
+ * @NFTA_TRACE_CHAIN: name of the chain (NLA_STRING)
+ * @NFTA_TRACE_RULE_HANDLE: numeric handle of the rule (NLA_U64)
+ * @NFTA_TRACE_TYPE: type of the event (NLA_U32: nft_trace_types)
+ * @NFTA_TRACE_VERDICT: verdict returned by hook (NLA_NESTED: nft_verdicts)
+ * @NFTA_TRACE_ID: pseudo-id, same for each skb traced (NLA_U32)
+ * @NFTA_TRACE_LL_HEADER: linklayer header (NLA_BINARY)
+ * @NFTA_TRACE_NETWORK_HEADER: network header (NLA_BINARY)
+ * @NFTA_TRACE_TRANSPORT_HEADER: transport header (NLA_BINARY)
+ * @NFTA_TRACE_IIF: indev ifindex (NLA_U32)
+ * @NFTA_TRACE_IIFTYPE: netdev->type of indev (NLA_U16)
+ * @NFTA_TRACE_OIF: outdev ifindex (NLA_U32)
+ * @NFTA_TRACE_OIFTYPE: netdev->type of outdev (NLA_U16)
+ * @NFTA_TRACE_MARK: nfmark (NLA_U32)
+ * @NFTA_TRACE_NFPROTO: nf protocol processed (NLA_U32)
+ * @NFTA_TRACE_POLICY: policy that decided fate of packet (NLA_U32)
+ */
+enum nft_trace_attibutes {
+ NFTA_TRACE_UNSPEC,
+ NFTA_TRACE_TABLE,
+ NFTA_TRACE_CHAIN,
+ NFTA_TRACE_RULE_HANDLE,
+ NFTA_TRACE_TYPE,
+ NFTA_TRACE_VERDICT,
+ NFTA_TRACE_ID,
+ NFTA_TRACE_LL_HEADER,
+ NFTA_TRACE_NETWORK_HEADER,
+ NFTA_TRACE_TRANSPORT_HEADER,
+ NFTA_TRACE_IIF,
+ NFTA_TRACE_IIFTYPE,
+ NFTA_TRACE_OIF,
+ NFTA_TRACE_OIFTYPE,
+ NFTA_TRACE_MARK,
+ NFTA_TRACE_NFPROTO,
+ NFTA_TRACE_POLICY,
+ __NFTA_TRACE_MAX
+};
+#define NFTA_TRACE_MAX (__NFTA_TRACE_MAX - 1)
+
+enum nft_trace_types {
+ NFT_TRACETYPE_UNSPEC,
+ NFT_TRACETYPE_POLICY,
+ NFT_TRACETYPE_RETURN,
+ NFT_TRACETYPE_RULE,
+ __NFT_TRACETYPE_MAX
+};
+#define NFT_TRACETYPE_MAX (__NFT_TRACETYPE_MAX - 1)
#endif /* _LINUX_NF_TABLES_H */