All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ryoga Saito <contact@proelbtn.com>
To: netfilter-devel@vger.kernel.org
Cc: pablo@netfilter.org, stefano.salsano@uniroma2.it,
	andrea.mayer@uniroma2.it, davem@davemloft.net, kuba@kernel.org,
	yoshfuji@linux-ipv6.org, dsahern@kernel.org,
	Ryoga Saito <contact@proelbtn.com>
Subject: [PATCH v2 2/2] netfilter: add netfilter hooks to SRv6 data plane
Date: Thu, 29 Jul 2021 08:37:13 +0000	[thread overview]
Message-ID: <7b59389116e4609487fe9a5696993727f3f82a72.1627546390.git.contact@proelbtn.com> (raw)
In-Reply-To: <cover.1627546390.git.contact@proelbtn.com>

This patch introduces netfilter hooks for solving the problem that
conntrack couldn't record both inner flows and outer flows.

Signed-off-by: Ryoga Saito <contact@proelbtn.com>
---
 net/ipv6/seg6_iptunnel.c |  68 +++++++++++++++++++++--
 net/ipv6/seg6_local.c    | 115 +++++++++++++++++++++++++++------------
 2 files changed, 141 insertions(+), 42 deletions(-)

diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index 897fa59c47de..77a2aafcb52f 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -26,6 +26,7 @@
 #ifdef CONFIG_IPV6_SEG6_HMAC
 #include <net/seg6_hmac.h>
 #endif
+#include <net/netfilter/nf_conntrack.h>
 
 static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo)
 {
@@ -295,25 +296,33 @@ static int seg6_do_srh(struct sk_buff *skb)
 
 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
+	nf_reset_ct(skb);
 
 	return 0;
 }
 
-static int seg6_input(struct sk_buff *skb)
+static int seg6_input_finish(struct net *net, struct sock *sk,
+			     struct sk_buff *skb)
+{
+	return dst_input(skb);
+}
+
+static int seg6_input_core(struct net *net, struct sock *sk,
+			   struct sk_buff *skb)
 {
 	struct dst_entry *orig_dst = skb_dst(skb);
 	struct dst_entry *dst = NULL;
-	struct seg6_lwt *slwt;
+	struct seg6_lwt *slwt = NULL;
 	int err;
 
+	slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
+
 	err = seg6_do_srh(skb);
 	if (unlikely(err)) {
 		kfree_skb(skb);
 		return err;
 	}
 
-	slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
-
 	preempt_disable();
 	dst = dst_cache_get(&slwt->cache);
 	preempt_enable();
@@ -337,10 +346,35 @@ static int seg6_input(struct sk_buff *skb)
 	if (unlikely(err))
 		return err;
 
-	return dst_input(skb);
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
+			       dev_net(skb->dev), NULL, skb, NULL,
+			       skb_dst(skb)->dev, seg6_input_finish);
+
+	return seg6_input_finish(dev_net(skb->dev), NULL, skb);
 }
 
-static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+static int seg6_input(struct sk_buff *skb)
+{
+	int proto;
+
+	if (skb->protocol == htons(ETH_P_IPV6))
+		proto = NFPROTO_IPV6;
+	else if (skb->protocol == htons(ETH_P_IP))
+		proto = NFPROTO_IPV4;
+	else
+		return -EINVAL;
+
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(proto, NF_INET_POST_ROUTING, dev_net(skb->dev),
+			       NULL, skb, NULL, skb_dst(skb)->dev,
+			       seg6_input_core);
+
+	return seg6_input_core(dev_net(skb->dev), NULL, skb);
+}
+
+static int seg6_output_core(struct net *net, struct sock *sk,
+			    struct sk_buff *skb)
 {
 	struct dst_entry *orig_dst = skb_dst(skb);
 	struct dst_entry *dst = NULL;
@@ -387,12 +421,34 @@ static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	if (unlikely(err))
 		goto drop;
 
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,
+			       NULL, skb_dst(skb)->dev, dst_output);
+
 	return dst_output(net, sk, skb);
 drop:
 	kfree_skb(skb);
 	return err;
 }
 
+static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	int proto;
+
+	if (skb->protocol == htons(ETH_P_IPV6))
+		proto = NFPROTO_IPV6;
+	else if (skb->protocol == htons(ETH_P_IP))
+		proto = NFPROTO_IPV4;
+	else
+		return -EINVAL;
+
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(proto, NF_INET_POST_ROUTING, net, sk, skb, NULL,
+			       skb_dst(skb)->dev, seg6_output_core);
+
+	return seg6_output_core(net, sk, skb);
+}
+
 static int seg6_build_state(struct net *net, struct nlattr *nla,
 			    unsigned int family, const void *cfg,
 			    struct lwtunnel_state **ts,
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index 60bf3b877957..d883475be043 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -30,6 +30,7 @@
 #include <net/seg6_local.h>
 #include <linux/etherdevice.h>
 #include <linux/bpf.h>
+#include <net/netfilter/nf_conntrack.h>
 
 #define SEG6_F_ATTR(i)		BIT(i)
 
@@ -413,12 +414,33 @@ static int input_action_end_dx2(struct sk_buff *skb,
 	return -EINVAL;
 }
 
+static int input_action_end_dx6_finish(struct net *net, struct sock *sk,
+				       struct sk_buff *skb)
+{
+	struct dst_entry *orig_dst = skb_dst(skb);
+	struct seg6_local_lwt *slwt = NULL;
+	struct in6_addr *nhaddr = NULL;
+
+	slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
+
+	/* The inner packet is not associated to any local interface,
+	 * so we do not call netif_rx().
+	 *
+	 * If slwt->nh6 is set to ::, then lookup the nexthop for the
+	 * inner packet's DA. Otherwise, use the specified nexthop.
+	 */
+	if (!ipv6_addr_any(&slwt->nh6))
+		nhaddr = &slwt->nh6;
+
+	seg6_lookup_nexthop(skb, nhaddr, 0);
+
+	return dst_input(skb);
+}
+
 /* decapsulate and forward to specified nexthop */
 static int input_action_end_dx6(struct sk_buff *skb,
 				struct seg6_local_lwt *slwt)
 {
-	struct in6_addr *nhaddr = NULL;
-
 	/* this function accepts IPv6 encapsulated packets, with either
 	 * an SRH with SL=0, or no SRH.
 	 */
@@ -429,55 +451,64 @@ static int input_action_end_dx6(struct sk_buff *skb,
 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 		goto drop;
 
-	/* The inner packet is not associated to any local interface,
-	 * so we do not call netif_rx().
-	 *
-	 * If slwt->nh6 is set to ::, then lookup the nexthop for the
-	 * inner packet's DA. Otherwise, use the specified nexthop.
-	 */
-
-	if (!ipv6_addr_any(&slwt->nh6))
-		nhaddr = &slwt->nh6;
-
 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
+	nf_reset_ct(skb);
 
-	seg6_lookup_nexthop(skb, nhaddr, 0);
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
+			       dev_net(skb->dev), NULL, skb, NULL,
+			       skb_dst(skb)->dev, input_action_end_dx6_finish);
 
-	return dst_input(skb);
+	return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb);
 drop:
 	kfree_skb(skb);
 	return -EINVAL;
 }
 
-static int input_action_end_dx4(struct sk_buff *skb,
-				struct seg6_local_lwt *slwt)
+static int input_action_end_dx4_finish(struct net *net, struct sock *sk,
+				       struct sk_buff *skb)
 {
+	struct dst_entry *orig_dst = skb_dst(skb);
+	struct seg6_local_lwt *slwt = NULL;
 	struct iphdr *iph;
 	__be32 nhaddr;
 	int err;
 
-	if (!decap_and_validate(skb, IPPROTO_IPIP))
-		goto drop;
-
-	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
-		goto drop;
-
-	skb->protocol = htons(ETH_P_IP);
+	slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
 
 	iph = ip_hdr(skb);
-
 	nhaddr = slwt->nh4.s_addr ?: iph->daddr;
 
 	skb_dst_drop(skb);
 
-	skb_set_transport_header(skb, sizeof(struct iphdr));
-
 	err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
-	if (err)
-		goto drop;
+	if (err) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
 
 	return dst_input(skb);
+}
 
+static int input_action_end_dx4(struct sk_buff *skb,
+				struct seg6_local_lwt *slwt)
+{
+	if (!decap_and_validate(skb, IPPROTO_IPIP))
+		goto drop;
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto drop;
+
+	skb->protocol = htons(ETH_P_IP);
+	skb_set_transport_header(skb, sizeof(struct iphdr));
+	nf_reset_ct(skb);
+
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
+			       dev_net(skb->dev), NULL, skb, NULL,
+			       skb_dst(skb)->dev, input_action_end_dx4_finish);
+
+	return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb);
 drop:
 	kfree_skb(skb);
 	return -EINVAL;
@@ -645,6 +676,7 @@ static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,
 	skb_dst_drop(skb);
 
 	skb_set_transport_header(skb, hdrlen);
+	nf_reset_ct(skb);
 
 	return end_dt_vrf_rcv(skb, family, vrf);
 
@@ -1078,22 +1110,18 @@ static void seg6_local_update_counters(struct seg6_local_lwt *slwt,
 	u64_stats_update_end(&pcounters->syncp);
 }
 
-static int seg6_local_input(struct sk_buff *skb)
+static int seg6_local_input_core(struct net *net, struct sock *sk,
+				 struct sk_buff *skb)
 {
 	struct dst_entry *orig_dst = skb_dst(skb);
+	struct seg6_local_lwt *slwt = NULL;
 	struct seg6_action_desc *desc;
-	struct seg6_local_lwt *slwt;
 	unsigned int len = skb->len;
 	int rc;
 
-	if (skb->protocol != htons(ETH_P_IPV6)) {
-		kfree_skb(skb);
-		return -EINVAL;
-	}
-
 	slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
-	desc = slwt->desc;
 
+	desc = slwt->desc;
 	rc = desc->input(skb, slwt);
 
 	if (!seg6_lwtunnel_counters_enabled(slwt))
@@ -1104,6 +1132,21 @@ static int seg6_local_input(struct sk_buff *skb)
 	return rc;
 }
 
+static int seg6_local_input(struct sk_buff *skb)
+{
+	if (skb->protocol != htons(ETH_P_IPV6)) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
+			       dev_net(skb->dev), NULL, skb, skb->dev, NULL,
+			       seg6_local_input_core);
+
+	return seg6_local_input_core(dev_net(skb->dev), NULL, skb);
+}
+
 static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
 	[SEG6_LOCAL_ACTION]	= { .type = NLA_U32 },
 	[SEG6_LOCAL_SRH]	= { .type = NLA_BINARY },
-- 
2.25.1


      parent reply	other threads:[~2021-07-29  8:53 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-29  8:37 [PATCH v2 0/2] net: add netfilter hooks to track SRv6-encapsulated flows Ryoga Saito
2021-07-29  8:37 ` [PATCH v2 1/2] netfilter: add new sysctl toggle for lightweight tunnel netfilter hooks Ryoga Saito
2021-07-29 12:41   ` kernel test robot
2021-07-29 12:41     ` kernel test robot
2021-07-29  8:37 ` Ryoga Saito [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=7b59389116e4609487fe9a5696993727f3f82a72.1627546390.git.contact@proelbtn.com \
    --to=contact@proelbtn.com \
    --cc=andrea.mayer@uniroma2.it \
    --cc=davem@davemloft.net \
    --cc=dsahern@kernel.org \
    --cc=kuba@kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=pablo@netfilter.org \
    --cc=stefano.salsano@uniroma2.it \
    --cc=yoshfuji@linux-ipv6.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.