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@xxxxxxxxxxxx>
---
net/ipv6/seg6_iptunnel.c | 74 ++++++++++++++++++++++++--
net/ipv6/seg6_local.c | 110 +++++++++++++++++++++++++++------------
2 files changed, 148 insertions(+), 36 deletions(-)
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index 897fa59c47de..f0288464a06f 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/lwtunnel.h>
static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo)
{
@@ -295,11 +296,19 @@ 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;
@@ -337,10 +346,41 @@ static int seg6_input(struct sk_buff *skb)
if (unlikely(err))
return err;
- return dst_input(skb);
+ if (static_branch_unlikely(&nf_hooks_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_nf(struct sk_buff *skb)
+{
+ struct net_device *dev = skb_dst(skb)->dev;
+ struct net *net = dev_net(skb->dev);
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, NULL,
+ skb, NULL, dev, seg6_input_core);
+ case htons(ETH_P_IPV6):
+ return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, NULL,
+ skb, NULL, dev, seg6_input_core);
+ }
+
+ return -EINVAL;
+}
+
+static int seg6_input(struct sk_buff *skb)
+{
+ if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
+ return seg6_input_nf(skb);
+
+ 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 +427,40 @@ static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
if (unlikely(err))
goto drop;
+ if (static_branch_unlikely(&nf_hooks_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_nf(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct net_device *dev = skb_dst(skb)->dev;
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
+ NULL, dev, seg6_output_core);
+ case htons(ETH_P_IPV6):
+ return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
+ NULL, dev, seg6_output_core);
+ }
+
+ return -EINVAL;
+}
+
+static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
+ return seg6_output_nf(net, sk, skb);
+
+ 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..cc9d573fc85a 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/lwtunnel.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 in6_addr *nhaddr = NULL;
+ struct seg6_local_lwt *slwt;
+
+ 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.
*/
@@ -429,40 +451,30 @@ 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_hooks_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;
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);
@@ -470,14 +482,34 @@ static int input_action_end_dx4(struct sk_buff *skb,
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_hooks_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 +677,7 @@ 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);
@@ -1078,7 +1111,8 @@ 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_action_desc *desc;
@@ -1086,11 +1120,6 @@ static int seg6_local_input(struct sk_buff *skb)
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;
@@ -1104,6 +1133,21 @@ 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_hooks_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
