mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 21:21:41 +00:00
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>
This commit is contained in:
Pablo Neira Ayuso
parent
97add9f0d6
commit
0995210753
@ -969,6 +969,8 @@ static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
|
||||
&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,
|
||||
|
||||
@ -378,7 +378,7 @@ static inline int ip6_forward_finish(struct net *net, struct sock *sk,
|
||||
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;
|
||||
@ -398,6 +398,7 @@ static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
|
||||
|
||||
return mtu;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(ip6_dst_mtu_forward);
|
||||
|
||||
static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
|
||||
{
|
||||
|
||||
@ -71,6 +71,14 @@ 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
|
||||
|
||||
@ -45,6 +45,9 @@ obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redir_ipv6.o
|
||||
obj-$(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
|
||||
|
||||
277
net/ipv6/netfilter/nf_flow_table_ipv6.c
Normal file
277
net/ipv6/netfilter/nf_flow_table_ipv6.c
Normal file
@ -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);
|
||||
Loading…
Reference in New Issue
Block a user