From 972d3876faa8a9195122b2d2bcd3155f904fff37 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Wed, 7 Dec 2016 13:48:27 +0100 Subject: [PATCH] flow dissector: ICMP support 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 Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- 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 @@ -57,6 +57,28 @@ 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 @@ -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 @@ ip_proto_again: 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; -- 2.20.1