[PATCH net-next v6 1/2] flow dissector: ICMP support
From: Simon Horman <hidden>
Date: 2016-12-07 12:48:34
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Allow dissection of ICMP(V6) type and code. This should only occur if a packet is ICMP(V6) and the dissector has FLOW_DISSECTOR_KEY_ICMP set. There are currently no users of FLOW_DISSECTOR_KEY_ICMP. A follow-up patch will allow FLOW_DISSECTOR_KEY_ICMP to be used by the flower classifier. Signed-off-by: Simon Horman <redacted> --- v6 * Add signed-off-by line which went missing at some point v5 * Drop remaining helpers v4 * Do not add icmp to struct flow_keys, it is not needed * Do not test for ICMP protocols in packet in __skb_flow_dissect, this is also not needed * Drop now unnecessary helpers v3 * Add FLOW_DISSECTOR_KEY_ICMP and use separate structure for ICMP, struct flow_dissector_key_icmp, which is a union with struct flow_dissector_key_ports in struct flow_keys. * Drop checks for !ICMP before accessing port field v2 * Include all helpers in this patch --- include/net/flow_dissector.h | 17 +++++++++++++++++ net/core/flow_dissector.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+)
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index c4f31666afd2..d896a33e00d4 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h@@ -104,6 +104,22 @@ struct flow_dissector_key_ports { }; }; +/** + * flow_dissector_key_icmp: + * @ports: type and code of ICMP header + * icmp: ICMP type (high) and code (low) + * type: ICMP type + * code: ICMP code + */ +struct flow_dissector_key_icmp { + union { + __be16 icmp; + struct { + u8 type; + u8 code; + }; + }; +}; /** * struct flow_dissector_key_eth_addrs:
@@ -122,6 +138,7 @@ enum flow_dissector_key_id { FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */ FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */ FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */ + FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */ FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */ FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs */ FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 1eb6f949e5b2..d6447dc10371 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c@@ -58,6 +58,28 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, EXPORT_SYMBOL(skb_flow_dissector_init); /** + * skb_flow_get_be16 - extract be16 entity + * @skb: sk_buff to extract from + * @poff: offset to extract at + * @data: raw buffer pointer to the packet + * @hlen: packet header length + * + * The function will try to retrieve a be32 entity at + * offset poff + */ +__be16 skb_flow_get_be16(const struct sk_buff *skb, int poff, void *data, + int hlen) +{ + __be16 *u, _u; + + u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u); + if (u) + return *u; + + return 0; +} + +/** * __skb_flow_get_ports - extract the upper layer ports and return them * @skb: sk_buff to extract the ports from * @thoff: transport header offset
@@ -117,6 +139,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector_key_basic *key_basic; struct flow_dissector_key_addrs *key_addrs; struct flow_dissector_key_ports *key_ports; + struct flow_dissector_key_icmp *key_icmp; struct flow_dissector_key_tags *key_tags; struct flow_dissector_key_vlan *key_vlan; struct flow_dissector_key_keyid *key_keyid;
@@ -546,6 +569,14 @@ bool __skb_flow_dissect(const struct sk_buff *skb, data, hlen); } + if (dissector_uses_key(flow_dissector, + FLOW_DISSECTOR_KEY_ICMP)) { + key_icmp = skb_flow_dissector_target(flow_dissector, + FLOW_DISSECTOR_KEY_ICMP, + target_container); + key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen); + } + out_good: ret = true;
--
2.7.0.rc3.207.g0ac5344