/branches/18.06.1/target/linux/generic/backport-4.14/324-v4.16-netfilter-flow-table-support-for-IPv6.patch |
@@ -0,0 +1,354 @@ |
From: Pablo Neira Ayuso <pablo@netfilter.org> |
Date: Sun, 7 Jan 2018 01:04:19 +0100 |
Subject: [PATCH] netfilter: flow table support for IPv6 |
|
This patch adds the IPv6 flow table type, that implements the datapath |
flow table to forward IPv6 traffic. |
|
This patch exports ip6_dst_mtu_forward() that is required to check for |
mtu to pass up packets that need PMTUD handling to the classic |
forwarding path. |
|
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
--- |
create mode 100644 net/ipv6/netfilter/nf_flow_table_ipv6.c |
|
--- a/include/net/ipv6.h |
+++ b/include/net/ipv6.h |
@@ -889,6 +889,8 @@ static inline struct sk_buff *ip6_finish |
&inet6_sk(sk)->cork); |
} |
|
+unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst); |
+ |
int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, |
struct flowi6 *fl6); |
struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6, |
--- a/net/ipv6/ip6_output.c |
+++ b/net/ipv6/ip6_output.c |
@@ -381,7 +381,7 @@ static inline int ip6_forward_finish(str |
return dst_output(net, sk, skb); |
} |
|
-static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) |
+unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) |
{ |
unsigned int mtu; |
struct inet6_dev *idev; |
@@ -401,6 +401,7 @@ static unsigned int ip6_dst_mtu_forward( |
|
return mtu; |
} |
+EXPORT_SYMBOL_GPL(ip6_dst_mtu_forward); |
|
static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) |
{ |
--- a/net/ipv6/netfilter/Kconfig |
+++ b/net/ipv6/netfilter/Kconfig |
@@ -99,6 +99,14 @@ config NFT_FIB_IPV6 |
endif # NF_TABLES_IPV6 |
endif # NF_TABLES |
|
+config NF_FLOW_TABLE_IPV6 |
+ select NF_FLOW_TABLE |
+ tristate "Netfilter flow table IPv6 module" |
+ help |
+ This option adds the flow table IPv6 support. |
+ |
+ To compile it as a module, choose M here. |
+ |
config NF_DUP_IPV6 |
tristate "Netfilter IPv6 packet duplication to alternate destination" |
depends on !NF_CONNTRACK || NF_CONNTRACK |
--- a/net/ipv6/netfilter/Makefile |
+++ b/net/ipv6/netfilter/Makefile |
@@ -45,6 +45,9 @@ obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redi |
obj-$(CONFIG_NFT_DUP_IPV6) += nft_dup_ipv6.o |
obj-$(CONFIG_NFT_FIB_IPV6) += nft_fib_ipv6.o |
|
+# flow table support |
+obj-$(CONFIG_NF_FLOW_TABLE_IPV6) += nf_flow_table_ipv6.o |
+ |
# matches |
obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o |
obj-$(CONFIG_IP6_NF_MATCH_EUI64) += ip6t_eui64.o |
--- /dev/null |
+++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c |
@@ -0,0 +1,277 @@ |
+#include <linux/kernel.h> |
+#include <linux/init.h> |
+#include <linux/module.h> |
+#include <linux/netfilter.h> |
+#include <linux/rhashtable.h> |
+#include <linux/ipv6.h> |
+#include <linux/netdevice.h> |
+#include <linux/ipv6.h> |
+#include <net/ipv6.h> |
+#include <net/ip6_route.h> |
+#include <net/neighbour.h> |
+#include <net/netfilter/nf_flow_table.h> |
+#include <net/netfilter/nf_tables.h> |
+/* For layer 4 checksum field offset. */ |
+#include <linux/tcp.h> |
+#include <linux/udp.h> |
+ |
+static int nf_flow_nat_ipv6_tcp(struct sk_buff *skb, unsigned int thoff, |
+ struct in6_addr *addr, |
+ struct in6_addr *new_addr) |
+{ |
+ struct tcphdr *tcph; |
+ |
+ if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) || |
+ skb_try_make_writable(skb, thoff + sizeof(*tcph))) |
+ return -1; |
+ |
+ tcph = (void *)(skb_network_header(skb) + thoff); |
+ inet_proto_csum_replace16(&tcph->check, skb, addr->s6_addr32, |
+ new_addr->s6_addr32, true); |
+ |
+ return 0; |
+} |
+ |
+static int nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff, |
+ struct in6_addr *addr, |
+ struct in6_addr *new_addr) |
+{ |
+ struct udphdr *udph; |
+ |
+ if (!pskb_may_pull(skb, thoff + sizeof(*udph)) || |
+ skb_try_make_writable(skb, thoff + sizeof(*udph))) |
+ return -1; |
+ |
+ udph = (void *)(skb_network_header(skb) + thoff); |
+ if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) { |
+ inet_proto_csum_replace16(&udph->check, skb, addr->s6_addr32, |
+ new_addr->s6_addr32, true); |
+ if (!udph->check) |
+ udph->check = CSUM_MANGLED_0; |
+ } |
+ |
+ return 0; |
+} |
+ |
+static int nf_flow_nat_ipv6_l4proto(struct sk_buff *skb, struct ipv6hdr *ip6h, |
+ unsigned int thoff, struct in6_addr *addr, |
+ struct in6_addr *new_addr) |
+{ |
+ switch (ip6h->nexthdr) { |
+ case IPPROTO_TCP: |
+ if (nf_flow_nat_ipv6_tcp(skb, thoff, addr, new_addr) < 0) |
+ return NF_DROP; |
+ break; |
+ case IPPROTO_UDP: |
+ if (nf_flow_nat_ipv6_udp(skb, thoff, addr, new_addr) < 0) |
+ return NF_DROP; |
+ break; |
+ } |
+ |
+ return 0; |
+} |
+ |
+static int nf_flow_snat_ipv6(const struct flow_offload *flow, |
+ struct sk_buff *skb, struct ipv6hdr *ip6h, |
+ unsigned int thoff, |
+ enum flow_offload_tuple_dir dir) |
+{ |
+ struct in6_addr addr, new_addr; |
+ |
+ switch (dir) { |
+ case FLOW_OFFLOAD_DIR_ORIGINAL: |
+ addr = ip6h->saddr; |
+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6; |
+ ip6h->saddr = new_addr; |
+ break; |
+ case FLOW_OFFLOAD_DIR_REPLY: |
+ addr = ip6h->daddr; |
+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6; |
+ ip6h->daddr = new_addr; |
+ break; |
+ default: |
+ return -1; |
+ } |
+ |
+ return nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); |
+} |
+ |
+static int nf_flow_dnat_ipv6(const struct flow_offload *flow, |
+ struct sk_buff *skb, struct ipv6hdr *ip6h, |
+ unsigned int thoff, |
+ enum flow_offload_tuple_dir dir) |
+{ |
+ struct in6_addr addr, new_addr; |
+ |
+ switch (dir) { |
+ case FLOW_OFFLOAD_DIR_ORIGINAL: |
+ addr = ip6h->daddr; |
+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6; |
+ ip6h->daddr = new_addr; |
+ break; |
+ case FLOW_OFFLOAD_DIR_REPLY: |
+ addr = ip6h->saddr; |
+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6; |
+ ip6h->saddr = new_addr; |
+ break; |
+ default: |
+ return -1; |
+ } |
+ |
+ return nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); |
+} |
+ |
+static int nf_flow_nat_ipv6(const struct flow_offload *flow, |
+ struct sk_buff *skb, |
+ enum flow_offload_tuple_dir dir) |
+{ |
+ struct ipv6hdr *ip6h = ipv6_hdr(skb); |
+ unsigned int thoff = sizeof(*ip6h); |
+ |
+ if (flow->flags & FLOW_OFFLOAD_SNAT && |
+ (nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 || |
+ nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir) < 0)) |
+ return -1; |
+ if (flow->flags & FLOW_OFFLOAD_DNAT && |
+ (nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 || |
+ nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir) < 0)) |
+ return -1; |
+ |
+ return 0; |
+} |
+ |
+static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev, |
+ struct flow_offload_tuple *tuple) |
+{ |
+ struct flow_ports *ports; |
+ struct ipv6hdr *ip6h; |
+ unsigned int thoff; |
+ |
+ if (!pskb_may_pull(skb, sizeof(*ip6h))) |
+ return -1; |
+ |
+ ip6h = ipv6_hdr(skb); |
+ |
+ if (ip6h->nexthdr != IPPROTO_TCP && |
+ ip6h->nexthdr != IPPROTO_UDP) |
+ return -1; |
+ |
+ thoff = sizeof(*ip6h); |
+ if (!pskb_may_pull(skb, thoff + sizeof(*ports))) |
+ return -1; |
+ |
+ 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; |
+ tuple->iifidx = dev->ifindex; |
+ |
+ return 0; |
+} |
+ |
+/* Based on ip_exceeds_mtu(). */ |
+static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu) |
+{ |
+ if (skb->len <= mtu) |
+ return false; |
+ |
+ if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu)) |
+ return false; |
+ |
+ return true; |
+} |
+ |
+static bool nf_flow_exceeds_mtu(struct sk_buff *skb, const struct rt6_info *rt) |
+{ |
+ u32 mtu; |
+ |
+ mtu = ip6_dst_mtu_forward(&rt->dst); |
+ if (__nf_flow_exceeds_mtu(skb, mtu)) |
+ return true; |
+ |
+ return false; |
+} |
+ |
+static unsigned int |
+nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, |
+ const struct nf_hook_state *state) |
+{ |
+ struct flow_offload_tuple_rhash *tuplehash; |
+ struct nf_flowtable *flow_table = priv; |
+ struct flow_offload_tuple tuple = {}; |
+ enum flow_offload_tuple_dir dir; |
+ struct flow_offload *flow; |
+ struct net_device *outdev; |
+ struct in6_addr *nexthop; |
+ struct ipv6hdr *ip6h; |
+ struct rt6_info *rt; |
+ |
+ if (skb->protocol != htons(ETH_P_IPV6)) |
+ return NF_ACCEPT; |
+ |
+ if (nf_flow_tuple_ipv6(skb, state->in, &tuple) < 0) |
+ return NF_ACCEPT; |
+ |
+ tuplehash = flow_offload_lookup(flow_table, &tuple); |
+ if (tuplehash == NULL) |
+ return NF_ACCEPT; |
+ |
+ outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.oifidx); |
+ if (!outdev) |
+ return NF_ACCEPT; |
+ |
+ dir = tuplehash->tuple.dir; |
+ flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]); |
+ |
+ rt = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache; |
+ if (unlikely(nf_flow_exceeds_mtu(skb, rt))) |
+ return NF_ACCEPT; |
+ |
+ if (skb_try_make_writable(skb, sizeof(*ip6h))) |
+ return NF_DROP; |
+ |
+ if (flow->flags & (FLOW_OFFLOAD_SNAT | FLOW_OFFLOAD_DNAT) && |
+ nf_flow_nat_ipv6(flow, skb, dir) < 0) |
+ return NF_DROP; |
+ |
+ flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT; |
+ ip6h = ipv6_hdr(skb); |
+ ip6h->hop_limit--; |
+ |
+ skb->dev = outdev; |
+ nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6); |
+ neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb); |
+ |
+ return NF_STOLEN; |
+} |
+ |
+static struct nf_flowtable_type flowtable_ipv6 = { |
+ .family = NFPROTO_IPV6, |
+ .params = &nf_flow_offload_rhash_params, |
+ .gc = nf_flow_offload_work_gc, |
+ .hook = nf_flow_offload_ipv6_hook, |
+ .owner = THIS_MODULE, |
+}; |
+ |
+static int __init nf_flow_ipv6_module_init(void) |
+{ |
+ nft_register_flowtable_type(&flowtable_ipv6); |
+ |
+ return 0; |
+} |
+ |
+static void __exit nf_flow_ipv6_module_exit(void) |
+{ |
+ nft_unregister_flowtable_type(&flowtable_ipv6); |
+} |
+ |
+module_init(nf_flow_ipv6_module_init); |
+module_exit(nf_flow_ipv6_module_exit); |
+ |
+MODULE_LICENSE("GPL"); |
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); |
+MODULE_ALIAS_NF_FLOWTABLE(AF_INET6); |