From 7a3f5b0de3647c854e34269c3332d7a1e902901a Mon Sep 17 00:00:00 2001 From: Ryoga Saito Date: Tue, 17 Aug 2021 08:39:37 +0000 Subject: netfilter: add netfilter hooks to SRv6 data plane This patch introduces netfilter hooks for solving the problem that conntrack couldn't record both inner flows and outer flows. This patch also introduces a new sysctl toggle for enabling lightweight tunnel netfilter hooks. Signed-off-by: Ryoga Saito Signed-off-by: Pablo Neira Ayuso --- net/ipv6/seg6_iptunnel.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 72 insertions(+), 3 deletions(-) (limited to 'net/ipv6/seg6_iptunnel.c') diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index 897fa59c47de..6ebc7aa24466 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -26,6 +26,8 @@ #ifdef CONFIG_IPV6_SEG6_HMAC #include #endif +#include +#include static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo) { @@ -295,11 +297,19 @@ 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 +347,41 @@ 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 +428,40 @@ 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, -- cgit v1.2.3