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 <contact@proelbtn.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Ryoga Saito
Pablo Neira Ayuso
Родитель
7bc416f147
Коммит
7a3f5b0de3
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@ -184,6 +184,13 @@ nf_conntrack_gre_timeout_stream - INTEGER (seconds)
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This extended timeout will be used in case there is an GRE stream
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detected.
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nf_hooks_lwtunnel - BOOLEAN
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- 0 - disabled (default)
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- not 0 - enabled
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If this option is enabled, the lightweight tunnel netfilter hooks are
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enabled. This option cannot be disabled once it is enabled.
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nf_flowtable_tcp_timeout - INTEGER (seconds)
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default 30
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@ -51,6 +51,9 @@ struct lwtunnel_encap_ops {
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};
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#ifdef CONFIG_LWTUNNEL
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DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
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void lwtstate_free(struct lwtunnel_state *lws);
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static inline struct lwtunnel_state *
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@ -0,0 +1,7 @@
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#include <linux/sysctl.h>
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#include <linux/types.h>
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#ifdef CONFIG_SYSCTL
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int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
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void *buffer, size_t *lenp, loff_t *ppos);
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#endif
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@ -23,6 +23,9 @@
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#include <net/ip6_fib.h>
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#include <net/rtnh.h>
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DEFINE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
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EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_enabled);
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#ifdef CONFIG_MODULES
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static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
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@ -26,6 +26,8 @@
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#ifdef CONFIG_IPV6_SEG6_HMAC
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#include <net/seg6_hmac.h>
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#endif
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#include <net/lwtunnel.h>
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#include <linux/netfilter.h>
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static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo)
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{
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@ -295,11 +297,19 @@ static int seg6_do_srh(struct sk_buff *skb)
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ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
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skb_set_transport_header(skb, sizeof(struct ipv6hdr));
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nf_reset_ct(skb);
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return 0;
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}
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static int seg6_input(struct sk_buff *skb)
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static int seg6_input_finish(struct net *net, struct sock *sk,
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struct sk_buff *skb)
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{
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return dst_input(skb);
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}
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static int seg6_input_core(struct net *net, struct sock *sk,
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struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct dst_entry *dst = NULL;
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@ -337,10 +347,41 @@ static int seg6_input(struct sk_buff *skb)
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if (unlikely(err))
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return err;
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return dst_input(skb);
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
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dev_net(skb->dev), NULL, skb, NULL,
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skb_dst(skb)->dev, seg6_input_finish);
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return seg6_input_finish(dev_net(skb->dev), NULL, skb);
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}
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static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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static int seg6_input_nf(struct sk_buff *skb)
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{
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struct net_device *dev = skb_dst(skb)->dev;
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struct net *net = dev_net(skb->dev);
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switch (skb->protocol) {
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case htons(ETH_P_IP):
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return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, NULL,
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skb, NULL, dev, seg6_input_core);
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case htons(ETH_P_IPV6):
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return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, NULL,
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skb, NULL, dev, seg6_input_core);
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}
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return -EINVAL;
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}
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static int seg6_input(struct sk_buff *skb)
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{
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return seg6_input_nf(skb);
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return seg6_input_core(dev_net(skb->dev), NULL, skb);
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}
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static int seg6_output_core(struct net *net, struct sock *sk,
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struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct dst_entry *dst = NULL;
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@ -387,12 +428,40 @@ static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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if (unlikely(err))
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goto drop;
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,
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NULL, skb_dst(skb)->dev, dst_output);
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return dst_output(net, sk, skb);
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drop:
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kfree_skb(skb);
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return err;
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}
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static int seg6_output_nf(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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struct net_device *dev = skb_dst(skb)->dev;
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switch (skb->protocol) {
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case htons(ETH_P_IP):
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return NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
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NULL, dev, seg6_output_core);
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case htons(ETH_P_IPV6):
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return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
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NULL, dev, seg6_output_core);
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}
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return -EINVAL;
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}
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static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return seg6_output_nf(net, sk, skb);
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return seg6_output_core(net, sk, skb);
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}
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static int seg6_build_state(struct net *net, struct nlattr *nla,
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unsigned int family, const void *cfg,
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struct lwtunnel_state **ts,
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@ -30,6 +30,8 @@
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#include <net/seg6_local.h>
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#include <linux/etherdevice.h>
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#include <linux/bpf.h>
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#include <net/lwtunnel.h>
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#include <linux/netfilter.h>
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#define SEG6_F_ATTR(i) BIT(i)
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@ -413,12 +415,33 @@ drop:
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return -EINVAL;
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}
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static int input_action_end_dx6_finish(struct net *net, struct sock *sk,
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struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct in6_addr *nhaddr = NULL;
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struct seg6_local_lwt *slwt;
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slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
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/* The inner packet is not associated to any local interface,
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* so we do not call netif_rx().
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*
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* If slwt->nh6 is set to ::, then lookup the nexthop for the
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* inner packet's DA. Otherwise, use the specified nexthop.
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*/
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if (!ipv6_addr_any(&slwt->nh6))
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nhaddr = &slwt->nh6;
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seg6_lookup_nexthop(skb, nhaddr, 0);
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return dst_input(skb);
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}
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/* decapsulate and forward to specified nexthop */
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static int input_action_end_dx6(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
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{
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struct in6_addr *nhaddr = NULL;
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/* this function accepts IPv6 encapsulated packets, with either
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* an SRH with SL=0, or no SRH.
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*/
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@ -429,40 +452,30 @@ static int input_action_end_dx6(struct sk_buff *skb,
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if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
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goto drop;
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/* The inner packet is not associated to any local interface,
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* so we do not call netif_rx().
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*
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* If slwt->nh6 is set to ::, then lookup the nexthop for the
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* inner packet's DA. Otherwise, use the specified nexthop.
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*/
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if (!ipv6_addr_any(&slwt->nh6))
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nhaddr = &slwt->nh6;
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skb_set_transport_header(skb, sizeof(struct ipv6hdr));
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nf_reset_ct(skb);
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seg6_lookup_nexthop(skb, nhaddr, 0);
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
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dev_net(skb->dev), NULL, skb, NULL,
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skb_dst(skb)->dev, input_action_end_dx6_finish);
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return dst_input(skb);
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return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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static int input_action_end_dx4(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
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static int input_action_end_dx4_finish(struct net *net, struct sock *sk,
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struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct seg6_local_lwt *slwt;
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struct iphdr *iph;
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__be32 nhaddr;
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int err;
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if (!decap_and_validate(skb, IPPROTO_IPIP))
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goto drop;
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if (!pskb_may_pull(skb, sizeof(struct iphdr)))
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goto drop;
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skb->protocol = htons(ETH_P_IP);
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slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
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iph = ip_hdr(skb);
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@ -470,14 +483,34 @@ static int input_action_end_dx4(struct sk_buff *skb,
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skb_dst_drop(skb);
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skb_set_transport_header(skb, sizeof(struct iphdr));
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err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
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if (err)
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goto drop;
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if (err) {
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kfree_skb(skb);
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return -EINVAL;
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}
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return dst_input(skb);
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}
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static int input_action_end_dx4(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
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{
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if (!decap_and_validate(skb, IPPROTO_IPIP))
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goto drop;
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if (!pskb_may_pull(skb, sizeof(struct iphdr)))
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goto drop;
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skb->protocol = htons(ETH_P_IP);
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skb_set_transport_header(skb, sizeof(struct iphdr));
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nf_reset_ct(skb);
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
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dev_net(skb->dev), NULL, skb, NULL,
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skb_dst(skb)->dev, input_action_end_dx4_finish);
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return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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@ -645,6 +678,7 @@ static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,
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skb_dst_drop(skb);
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skb_set_transport_header(skb, hdrlen);
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nf_reset_ct(skb);
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return end_dt_vrf_rcv(skb, family, vrf);
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@ -1078,7 +1112,8 @@ static void seg6_local_update_counters(struct seg6_local_lwt *slwt,
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u64_stats_update_end(&pcounters->syncp);
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}
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static int seg6_local_input(struct sk_buff *skb)
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static int seg6_local_input_core(struct net *net, struct sock *sk,
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struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct seg6_action_desc *desc;
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@ -1086,11 +1121,6 @@ static int seg6_local_input(struct sk_buff *skb)
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unsigned int len = skb->len;
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int rc;
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if (skb->protocol != htons(ETH_P_IPV6)) {
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kfree_skb(skb);
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return -EINVAL;
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}
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slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
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desc = slwt->desc;
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@ -1104,6 +1134,21 @@ static int seg6_local_input(struct sk_buff *skb)
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return rc;
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}
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static int seg6_local_input(struct sk_buff *skb)
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{
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if (skb->protocol != htons(ETH_P_IPV6)) {
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kfree_skb(skb);
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return -EINVAL;
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}
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if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
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return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
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dev_net(skb->dev), NULL, skb, skb->dev, NULL,
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seg6_local_input_core);
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return seg6_local_input_core(dev_net(skb->dev), NULL, skb);
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}
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static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
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[SEG6_LOCAL_ACTION] = { .type = NLA_U32 },
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[SEG6_LOCAL_SRH] = { .type = NLA_BINARY },
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|
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|
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@ -212,3 +212,6 @@ obj-$(CONFIG_IP_SET) += ipset/
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# IPVS
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obj-$(CONFIG_IP_VS) += ipvs/
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# lwtunnel
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obj-$(CONFIG_LWTUNNEL) += nf_hooks_lwtunnel.o
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|
|
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|
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@ -22,6 +22,9 @@
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#include <net/netfilter/nf_conntrack_acct.h>
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#include <net/netfilter/nf_conntrack_zones.h>
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#include <net/netfilter/nf_conntrack_timestamp.h>
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#ifdef CONFIG_LWTUNNEL
|
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#include <net/netfilter/nf_hooks_lwtunnel.h>
|
||||
#endif
|
||||
#include <linux/rculist_nulls.h>
|
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|
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static bool enable_hooks __read_mostly;
|
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|
|
@ -612,6 +615,9 @@ enum nf_ct_sysctl_index {
|
|||
NF_SYSCTL_CT_PROTO_TIMEOUT_GRE,
|
||||
NF_SYSCTL_CT_PROTO_TIMEOUT_GRE_STREAM,
|
||||
#endif
|
||||
#ifdef CONFIG_LWTUNNEL
|
||||
NF_SYSCTL_CT_LWTUNNEL,
|
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#endif
|
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|
||||
__NF_SYSCTL_CT_LAST_SYSCTL,
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||||
};
|
||||
|
|
@ -958,6 +964,15 @@ static struct ctl_table nf_ct_sysctl_table[] = {
|
|||
.mode = 0644,
|
||||
.proc_handler = proc_dointvec_jiffies,
|
||||
},
|
||||
#endif
|
||||
#ifdef CONFIG_LWTUNNEL
|
||||
[NF_SYSCTL_CT_LWTUNNEL] = {
|
||||
.procname = "nf_hooks_lwtunnel",
|
||||
.data = NULL,
|
||||
.maxlen = sizeof(int),
|
||||
.mode = 0644,
|
||||
.proc_handler = nf_hooks_lwtunnel_sysctl_handler,
|
||||
},
|
||||
#endif
|
||||
{}
|
||||
};
|
||||
|
|
|
|||
|
|
@ -0,0 +1,53 @@
|
|||
// SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
#include <linux/sysctl.h>
|
||||
#include <net/lwtunnel.h>
|
||||
#include <net/netfilter/nf_hooks_lwtunnel.h>
|
||||
|
||||
static inline int nf_hooks_lwtunnel_get(void)
|
||||
{
|
||||
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
|
||||
return 1;
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int nf_hooks_lwtunnel_set(int enable)
|
||||
{
|
||||
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) {
|
||||
if (!enable)
|
||||
return -EBUSY;
|
||||
} else if (enable) {
|
||||
static_branch_enable(&nf_hooks_lwtunnel_enabled);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_SYSCTL
|
||||
int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
|
||||
void *buffer, size_t *lenp, loff_t *ppos)
|
||||
{
|
||||
int proc_nf_hooks_lwtunnel_enabled = 0;
|
||||
struct ctl_table tmp = {
|
||||
.procname = table->procname,
|
||||
.data = &proc_nf_hooks_lwtunnel_enabled,
|
||||
.maxlen = sizeof(int),
|
||||
.mode = table->mode,
|
||||
.extra1 = SYSCTL_ZERO,
|
||||
.extra2 = SYSCTL_ONE,
|
||||
};
|
||||
int ret;
|
||||
|
||||
if (!write)
|
||||
proc_nf_hooks_lwtunnel_enabled = nf_hooks_lwtunnel_get();
|
||||
|
||||
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
|
||||
|
||||
if (write && ret == 0)
|
||||
ret = nf_hooks_lwtunnel_set(proc_nf_hooks_lwtunnel_enabled);
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_sysctl_handler);
|
||||
#endif /* CONFIG_SYSCTL */
|
||||
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