From 55733350e5e8b70c5e54a30dbf98148c695f21f5 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Wed, 11 Jan 2017 14:05:42 +0100 Subject: [PATCH] flow disector: ARP support Allow dissection of (R)ARP operation hardware and protocol addresses for Ethernet hardware and IPv4 protocol addresses. There are currently no users of FLOW_DISSECTOR_KEY_ARP. A follow-up patch will allow FLOW_DISSECTOR_KEY_ARP 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 | 19 ++++++++++++ net/core/flow_dissector.c | 57 ++++++++++++++++++++++++++++++++++++ 2 files changed, 76 insertions(+) diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h index d896a33e00d4..ac9703018a3a 100644 --- a/include/net/flow_dissector.h +++ b/include/net/flow_dissector.h @@ -88,6 +88,24 @@ struct flow_dissector_key_addrs { }; }; +/** + * flow_dissector_key_arp: + * @ports: Operation, source and target addresses for an ARP header + * for Ethernet hardware addresses and IPv4 protocol addresses + * sip: Sender IP address + * tip: Target IP address + * op: Operation + * sha: Sender hardware address + * tpa: Target hardware address + */ +struct flow_dissector_key_arp { + __u32 sip; + __u32 tip; + __u8 op; + unsigned char sha[ETH_ALEN]; + unsigned char tha[ETH_ALEN]; +}; + /** * flow_dissector_key_tp_ports: * @ports: port numbers of Transport header @@ -141,6 +159,7 @@ enum flow_dissector_key_id { 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_ARP, /* struct flow_dissector_key_arp */ FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_flow_vlan */ FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */ FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */ diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index fe4e1531976c..5b3800fe20f3 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -138,6 +138,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector_key_control *key_control; struct flow_dissector_key_basic *key_basic; struct flow_dissector_key_addrs *key_addrs; + struct flow_dissector_key_arp *key_arp; struct flow_dissector_key_ports *key_ports; struct flow_dissector_key_icmp *key_icmp; struct flow_dissector_key_tags *key_tags; @@ -379,6 +380,62 @@ mpls: nhoff += FCOE_HEADER_LEN; goto out_good; + + case htons(ETH_P_ARP): + case htons(ETH_P_RARP): { + struct { + unsigned char ar_sha[ETH_ALEN]; + unsigned char ar_sip[4]; + unsigned char ar_tha[ETH_ALEN]; + unsigned char ar_tip[4]; + } *arp_eth, _arp_eth; + const struct arphdr *arp; + struct arphdr *_arp; + + arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data, + hlen, &_arp); + if (!arp) + goto out_bad; + + if (arp->ar_hrd != htons(ARPHRD_ETHER) || + arp->ar_pro != htons(ETH_P_IP) || + arp->ar_hln != ETH_ALEN || + arp->ar_pln != 4 || + (arp->ar_op != htons(ARPOP_REPLY) && + arp->ar_op != htons(ARPOP_REQUEST))) + goto out_bad; + + arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp), + sizeof(_arp_eth), data, + hlen - sizeof(_arp), + &_arp_eth); + if (!arp) + goto out_bad; + + if (dissector_uses_key(flow_dissector, + FLOW_DISSECTOR_KEY_ARP)) { + + key_arp = skb_flow_dissector_target(flow_dissector, + FLOW_DISSECTOR_KEY_ARP, + target_container); + + memcpy(&key_arp->sip, arp_eth->ar_sip, + sizeof(key_arp->sip)); + memcpy(&key_arp->tip, arp_eth->ar_tip, + sizeof(key_arp->tip)); + + /* Only store the lower byte of the opcode; + * this covers ARPOP_REPLY and ARPOP_REQUEST. + */ + key_arp->op = ntohs(arp->ar_op) & 0xff; + + ether_addr_copy(key_arp->sha, arp_eth->ar_sha); + ether_addr_copy(key_arp->tha, arp_eth->ar_tha); + } + + goto out_good; + } + default: goto out_bad; } -- 2.20.1