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Message-Id: <1583067523-1960-4-git-send-email-paulb@mellanox.com>
Date: Sun, 1 Mar 2020 14:58:43 +0200
From: Paul Blakey <paulb@...lanox.com>
To: Paul Blakey <paulb@...lanox.com>,
Saeed Mahameed <saeedm@...lanox.com>,
Oz Shlomo <ozsh@...lanox.com>,
Jakub Kicinski <jakub.kicinski@...ronome.com>,
Vlad Buslov <vladbu@...lanox.com>,
David Miller <davem@...emloft.net>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
Jiri Pirko <jiri@...lanox.com>, Roi Dayan <roid@...lanox.com>
Subject: [PATCH net-next v2 3/3] net/sched: act_ct: Software offload of established flows
Offload nf conntrack processing by looking up the 5-tuple in the
zone's flow table.
The nf conntrack module will process the packets until a connection is
in established state. Once in established state, the ct state pointer
(nf_conn) will be restored on the skb from a successful ft lookup.
Signed-off-by: Paul Blakey <paulb@...lanox.com>
Acked-by: Jiri Pirko <jiri@...lanox.com>
---
Changelog:
v1->v2:
Add !skip_add curly braces
Removed extra setting thoff again
Check tcp proto outside of tcf_ct_flow_table_check_tcp
net/sched/act_ct.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 158 insertions(+), 2 deletions(-)
diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index b512f20..c8b9837 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -195,6 +195,155 @@ static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft,
tcf_ct_flow_table_add(ct_ft, ct, tcp);
}
+static bool
+tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
+ struct flow_offload_tuple *tuple)
+{
+ struct flow_ports *ports;
+ unsigned int thoff;
+ struct iphdr *iph;
+
+ if (!pskb_may_pull(skb, sizeof(*iph)))
+ return false;
+
+ iph = ip_hdr(skb);
+ thoff = iph->ihl * 4;
+
+ if (ip_is_fragment(iph) ||
+ unlikely(thoff != sizeof(struct iphdr)))
+ return false;
+
+ if (iph->protocol != IPPROTO_TCP &&
+ iph->protocol != IPPROTO_UDP)
+ return false;
+
+ if (iph->ttl <= 1)
+ return false;
+
+ if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
+ return false;
+
+ ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+
+ tuple->src_v4.s_addr = iph->saddr;
+ tuple->dst_v4.s_addr = iph->daddr;
+ tuple->src_port = ports->source;
+ tuple->dst_port = ports->dest;
+ tuple->l3proto = AF_INET;
+ tuple->l4proto = iph->protocol;
+
+ return true;
+}
+
+static bool
+tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
+ struct flow_offload_tuple *tuple)
+{
+ struct flow_ports *ports;
+ struct ipv6hdr *ip6h;
+ unsigned int thoff;
+
+ if (!pskb_may_pull(skb, sizeof(*ip6h)))
+ return false;
+
+ ip6h = ipv6_hdr(skb);
+
+ if (ip6h->nexthdr != IPPROTO_TCP &&
+ ip6h->nexthdr != IPPROTO_UDP)
+ return false;
+
+ if (ip6h->hop_limit <= 1)
+ return false;
+
+ thoff = sizeof(*ip6h);
+ if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
+ return false;
+
+ ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+
+ tuple->src_v6 = ip6h->saddr;
+ tuple->dst_v6 = ip6h->daddr;
+ tuple->src_port = ports->source;
+ tuple->dst_port = ports->dest;
+ tuple->l3proto = AF_INET6;
+ tuple->l4proto = ip6h->nexthdr;
+
+ return true;
+}
+
+static bool tcf_ct_flow_table_check_tcp(struct flow_offload *flow,
+ struct sk_buff *skb,
+ unsigned int thoff)
+{
+ struct tcphdr *tcph;
+
+ if (!pskb_may_pull(skb, thoff + sizeof(*tcph)))
+ return false;
+
+ tcph = (void *)(skb_network_header(skb) + thoff);
+ if (unlikely(tcph->fin || tcph->rst)) {
+ flow_offload_teardown(flow);
+ return false;
+ }
+
+ return true;
+}
+
+static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
+ struct sk_buff *skb,
+ u8 family)
+{
+ struct nf_flowtable *nf_ft = &p->ct_ft->nf_ft;
+ struct flow_offload_tuple_rhash *tuplehash;
+ struct flow_offload_tuple tuple = {};
+ enum ip_conntrack_info ctinfo;
+ struct flow_offload *flow;
+ struct nf_conn *ct;
+ unsigned int thoff;
+ int ip_proto;
+ u8 dir;
+
+ /* Previously seen or loopback */
+ ct = nf_ct_get(skb, &ctinfo);
+ if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
+ return false;
+
+ switch (family) {
+ case NFPROTO_IPV4:
+ if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple))
+ return false;
+ break;
+ case NFPROTO_IPV6:
+ if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple))
+ return false;
+ break;
+ default:
+ return false;
+ }
+
+ tuplehash = flow_offload_lookup(nf_ft, &tuple);
+ if (!tuplehash)
+ return false;
+
+ dir = tuplehash->tuple.dir;
+ flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
+ ct = flow->ct;
+
+ ctinfo = dir == FLOW_OFFLOAD_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
+ IP_CT_ESTABLISHED_REPLY;
+
+ thoff = ip_hdr(skb)->ihl * 4;
+ ip_proto = ip_hdr(skb)->protocol;
+ if (ip_proto == IPPROTO_TCP &&
+ !tcf_ct_flow_table_check_tcp(flow, skb, thoff))
+ return false;
+
+ nf_conntrack_get(&ct->ct_general);
+ nf_ct_set(skb, ct, ctinfo);
+
+ return true;
+}
+
static int tcf_ct_flow_tables_init(void)
{
return rhashtable_init(&zones_ht, &zones_params);
@@ -563,6 +712,7 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
struct nf_hook_state state;
int nh_ofs, err, retval;
struct tcf_ct_params *p;
+ bool skip_add = false;
struct nf_conn *ct;
u8 family;
@@ -612,6 +762,11 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
*/
cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force);
if (!cached) {
+ if (!commit && tcf_ct_flow_table_lookup(p, skb, family)) {
+ skip_add = true;
+ goto do_nat;
+ }
+
/* Associate skb with specified zone. */
if (tmpl) {
ct = nf_ct_get(skb, &ctinfo);
@@ -629,6 +784,7 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
goto out_push;
}
+do_nat:
ct = nf_ct_get(skb, &ctinfo);
if (!ct)
goto out_push;
@@ -646,10 +802,10 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
* even if the connection is already confirmed.
*/
nf_conntrack_confirm(skb);
+ } else if (!skip_add) {
+ tcf_ct_flow_table_process_conn(p->ct_ft, ct, ctinfo);
}
- tcf_ct_flow_table_process_conn(p->ct_ft, ct, ctinfo);
-
out_push:
skb_push_rcsum(skb, nh_ofs);
--
1.8.3.1
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