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Date: Mon, 6 Mar 2017 16:39:51 +0100
From: Jiri Pirko <jiri@...nulli.us>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, tom@...bertland.com,
simon.horman@...ronome.com, eric.dumazet@...il.com,
dinan.gunawardena@...ronome.com, hadarh@...lanox.com, e@...g.me,
fgao@...ai8.com, mlxsw@...lanox.com
Subject: [patch net-next 1/5] flow_dissector: Move ARP dissection into a separate function
From: Jiri Pirko <jiri@...lanox.com>
Make the main flow_dissect function a bit smaller and move the ARP
dissection into a separate function. Along with that, do the ARP header
processing only in case the flow dissection user requires it.
Signed-off-by: Jiri Pirko <jiri@...lanox.com>
---
net/core/flow_dissector.c | 120 ++++++++++++++++++++++++++--------------------
1 file changed, 67 insertions(+), 53 deletions(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index c35aae1..d79fb8f 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -113,6 +113,66 @@ __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
}
EXPORT_SYMBOL(__skb_flow_get_ports);
+enum flow_dissect_ret {
+ FLOW_DISSECT_RET_OUT_GOOD,
+ FLOW_DISSECT_RET_OUT_BAD,
+};
+
+static enum flow_dissect_ret
+__skb_flow_dissect_arp(const struct sk_buff *skb,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data, int nhoff, int hlen)
+{
+ struct flow_dissector_key_arp *key_arp;
+ 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;
+
+ if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
+ return FLOW_DISSECT_RET_OUT_GOOD;
+
+ arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
+ hlen, &_arp);
+ if (!arp)
+ return FLOW_DISSECT_RET_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)))
+ return FLOW_DISSECT_RET_OUT_BAD;
+
+ arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
+ sizeof(_arp_eth), data,
+ hlen, &_arp_eth);
+ if (!arp_eth)
+ return FLOW_DISSECT_RET_OUT_BAD;
+
+ 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);
+
+ return FLOW_DISSECT_RET_OUT_GOOD;
+}
+
/**
* __skb_flow_dissect - extract the flow_keys struct and return it
* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
@@ -138,7 +198,6 @@ 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;
@@ -382,60 +441,15 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
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,
- &_arp_eth);
- if (!arp_eth)
+ case htons(ETH_P_RARP):
+ switch (__skb_flow_dissect_arp(skb, flow_dissector,
+ target_container, data,
+ nhoff, hlen)) {
+ case FLOW_DISSECT_RET_OUT_GOOD:
+ goto out_good;
+ case FLOW_DISSECT_RET_OUT_BAD:
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;
}
--
2.7.4
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