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 <simon.horman@netronome.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Simon Horman 2017-01-11 14:05:42 +01:00 committed by David S. Miller
parent 380043b9de
commit 55733350e5
2 changed files with 76 additions and 0 deletions

View File

@ -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 */

View File

@ -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;
}