/branches/18.06.1/target/linux/generic/backport-4.14/322-v4.16-netfilter-add-generic-flow-table-infrastructure.patch |
@@ -0,0 +1,586 @@ |
From: Pablo Neira Ayuso <pablo@netfilter.org> |
Date: Sun, 7 Jan 2018 01:04:11 +0100 |
Subject: [PATCH] netfilter: add generic flow table infrastructure |
|
This patch defines the API to interact with flow tables, this allows to |
add, delete and lookup for entries in the flow table. This also adds the |
generic garbage code that removes entries that have expired, ie. no |
traffic has been seen for a while. |
|
Users of the flow table infrastructure can delete entries via |
flow_offload_dead(), which sets the dying bit, this signals the garbage |
collector to release an entry from user context. |
|
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
--- |
create mode 100644 net/netfilter/nf_flow_table.c |
|
--- a/include/net/netfilter/nf_flow_table.h |
+++ b/include/net/netfilter/nf_flow_table.h |
@@ -1,7 +1,12 @@ |
#ifndef _NF_FLOW_TABLE_H |
#define _NF_FLOW_TABLE_H |
|
+#include <linux/in.h> |
+#include <linux/in6.h> |
+#include <linux/netdevice.h> |
#include <linux/rhashtable.h> |
+#include <linux/rcupdate.h> |
+#include <net/dst.h> |
|
struct nf_flowtable; |
|
@@ -20,4 +25,93 @@ struct nf_flowtable { |
struct delayed_work gc_work; |
}; |
|
+enum flow_offload_tuple_dir { |
+ FLOW_OFFLOAD_DIR_ORIGINAL, |
+ FLOW_OFFLOAD_DIR_REPLY, |
+ __FLOW_OFFLOAD_DIR_MAX = FLOW_OFFLOAD_DIR_REPLY, |
+}; |
+#define FLOW_OFFLOAD_DIR_MAX (__FLOW_OFFLOAD_DIR_MAX + 1) |
+ |
+struct flow_offload_tuple { |
+ union { |
+ struct in_addr src_v4; |
+ struct in6_addr src_v6; |
+ }; |
+ union { |
+ struct in_addr dst_v4; |
+ struct in6_addr dst_v6; |
+ }; |
+ struct { |
+ __be16 src_port; |
+ __be16 dst_port; |
+ }; |
+ |
+ int iifidx; |
+ |
+ u8 l3proto; |
+ u8 l4proto; |
+ u8 dir; |
+ |
+ int oifidx; |
+ |
+ struct dst_entry *dst_cache; |
+}; |
+ |
+struct flow_offload_tuple_rhash { |
+ struct rhash_head node; |
+ struct flow_offload_tuple tuple; |
+}; |
+ |
+#define FLOW_OFFLOAD_SNAT 0x1 |
+#define FLOW_OFFLOAD_DNAT 0x2 |
+#define FLOW_OFFLOAD_DYING 0x4 |
+ |
+struct flow_offload { |
+ struct flow_offload_tuple_rhash tuplehash[FLOW_OFFLOAD_DIR_MAX]; |
+ u32 flags; |
+ union { |
+ /* Your private driver data here. */ |
+ u32 timeout; |
+ }; |
+}; |
+ |
+#define NF_FLOW_TIMEOUT (30 * HZ) |
+ |
+struct nf_flow_route { |
+ struct { |
+ struct dst_entry *dst; |
+ int ifindex; |
+ } tuple[FLOW_OFFLOAD_DIR_MAX]; |
+}; |
+ |
+struct flow_offload *flow_offload_alloc(struct nf_conn *ct, |
+ struct nf_flow_route *route); |
+void flow_offload_free(struct flow_offload *flow); |
+ |
+int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow); |
+void flow_offload_del(struct nf_flowtable *flow_table, struct flow_offload *flow); |
+struct flow_offload_tuple_rhash *flow_offload_lookup(struct nf_flowtable *flow_table, |
+ struct flow_offload_tuple *tuple); |
+int nf_flow_table_iterate(struct nf_flowtable *flow_table, |
+ void (*iter)(struct flow_offload *flow, void *data), |
+ void *data); |
+void nf_flow_offload_work_gc(struct work_struct *work); |
+extern const struct rhashtable_params nf_flow_offload_rhash_params; |
+ |
+void flow_offload_dead(struct flow_offload *flow); |
+ |
+int nf_flow_snat_port(const struct flow_offload *flow, |
+ struct sk_buff *skb, unsigned int thoff, |
+ u8 protocol, enum flow_offload_tuple_dir dir); |
+int nf_flow_dnat_port(const struct flow_offload *flow, |
+ struct sk_buff *skb, unsigned int thoff, |
+ u8 protocol, enum flow_offload_tuple_dir dir); |
+ |
+struct flow_ports { |
+ __be16 source, dest; |
+}; |
+ |
+#define MODULE_ALIAS_NF_FLOWTABLE(family) \ |
+ MODULE_ALIAS("nf-flowtable-" __stringify(family)) |
+ |
#endif /* _FLOW_OFFLOAD_H */ |
--- a/net/netfilter/Kconfig |
+++ b/net/netfilter/Kconfig |
@@ -667,6 +667,13 @@ endif # NF_TABLES_NETDEV |
|
endif # NF_TABLES |
|
+config NF_FLOW_TABLE |
+ tristate "Netfilter flow table module" |
+ help |
+ This option adds the flow table core infrastructure. |
+ |
+ To compile it as a module, choose M here. |
+ |
config NETFILTER_XTABLES |
tristate "Netfilter Xtables support (required for ip_tables)" |
default m if NETFILTER_ADVANCED=n |
--- a/net/netfilter/Makefile |
+++ b/net/netfilter/Makefile |
@@ -110,6 +110,9 @@ obj-$(CONFIG_NFT_FIB_NETDEV) += nft_fib_ |
obj-$(CONFIG_NFT_DUP_NETDEV) += nft_dup_netdev.o |
obj-$(CONFIG_NFT_FWD_NETDEV) += nft_fwd_netdev.o |
|
+# flow table infrastructure |
+obj-$(CONFIG_NF_FLOW_TABLE) += nf_flow_table.o |
+ |
# generic X tables |
obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o |
|
--- /dev/null |
+++ b/net/netfilter/nf_flow_table.c |
@@ -0,0 +1,429 @@ |
+#include <linux/kernel.h> |
+#include <linux/init.h> |
+#include <linux/module.h> |
+#include <linux/netfilter.h> |
+#include <linux/rhashtable.h> |
+#include <linux/netdevice.h> |
+#include <net/netfilter/nf_flow_table.h> |
+#include <net/netfilter/nf_conntrack.h> |
+#include <net/netfilter/nf_conntrack_core.h> |
+#include <net/netfilter/nf_conntrack_tuple.h> |
+ |
+struct flow_offload_entry { |
+ struct flow_offload flow; |
+ struct nf_conn *ct; |
+ struct rcu_head rcu_head; |
+}; |
+ |
+struct flow_offload * |
+flow_offload_alloc(struct nf_conn *ct, struct nf_flow_route *route) |
+{ |
+ struct flow_offload_entry *entry; |
+ struct flow_offload *flow; |
+ |
+ if (unlikely(nf_ct_is_dying(ct) || |
+ !atomic_inc_not_zero(&ct->ct_general.use))) |
+ return NULL; |
+ |
+ entry = kzalloc(sizeof(*entry), GFP_ATOMIC); |
+ if (!entry) |
+ goto err_ct_refcnt; |
+ |
+ flow = &entry->flow; |
+ |
+ if (!dst_hold_safe(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst)) |
+ goto err_dst_cache_original; |
+ |
+ if (!dst_hold_safe(route->tuple[FLOW_OFFLOAD_DIR_REPLY].dst)) |
+ goto err_dst_cache_reply; |
+ |
+ entry->ct = ct; |
+ |
+ switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num) { |
+ case NFPROTO_IPV4: |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4 = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4 = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4 = |
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4 = |
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in; |
+ break; |
+ case NFPROTO_IPV6: |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6 = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.in6; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6 = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.in6; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6 = |
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.in6; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6 = |
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.in6; |
+ break; |
+ } |
+ |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l3proto = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l4proto = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.l3proto = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.l4proto = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum; |
+ |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache = |
+ route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache = |
+ route->tuple[FLOW_OFFLOAD_DIR_REPLY].dst; |
+ |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port = |
+ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u.tcp.port; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port = |
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.tcp.port; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port = |
+ ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port; |
+ |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dir = |
+ FLOW_OFFLOAD_DIR_ORIGINAL; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dir = |
+ FLOW_OFFLOAD_DIR_REPLY; |
+ |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.iifidx = |
+ route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].ifindex; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.oifidx = |
+ route->tuple[FLOW_OFFLOAD_DIR_REPLY].ifindex; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.iifidx = |
+ route->tuple[FLOW_OFFLOAD_DIR_REPLY].ifindex; |
+ flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.oifidx = |
+ route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].ifindex; |
+ |
+ if (ct->status & IPS_SRC_NAT) |
+ flow->flags |= FLOW_OFFLOAD_SNAT; |
+ else if (ct->status & IPS_DST_NAT) |
+ flow->flags |= FLOW_OFFLOAD_DNAT; |
+ |
+ return flow; |
+ |
+err_dst_cache_reply: |
+ dst_release(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst); |
+err_dst_cache_original: |
+ kfree(entry); |
+err_ct_refcnt: |
+ nf_ct_put(ct); |
+ |
+ return NULL; |
+} |
+EXPORT_SYMBOL_GPL(flow_offload_alloc); |
+ |
+void flow_offload_free(struct flow_offload *flow) |
+{ |
+ struct flow_offload_entry *e; |
+ |
+ dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache); |
+ dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache); |
+ e = container_of(flow, struct flow_offload_entry, flow); |
+ kfree(e); |
+} |
+EXPORT_SYMBOL_GPL(flow_offload_free); |
+ |
+void flow_offload_dead(struct flow_offload *flow) |
+{ |
+ flow->flags |= FLOW_OFFLOAD_DYING; |
+} |
+EXPORT_SYMBOL_GPL(flow_offload_dead); |
+ |
+int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow) |
+{ |
+ flow->timeout = (u32)jiffies; |
+ |
+ rhashtable_insert_fast(&flow_table->rhashtable, |
+ &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node, |
+ *flow_table->type->params); |
+ rhashtable_insert_fast(&flow_table->rhashtable, |
+ &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node, |
+ *flow_table->type->params); |
+ return 0; |
+} |
+EXPORT_SYMBOL_GPL(flow_offload_add); |
+ |
+void flow_offload_del(struct nf_flowtable *flow_table, |
+ struct flow_offload *flow) |
+{ |
+ struct flow_offload_entry *e; |
+ |
+ rhashtable_remove_fast(&flow_table->rhashtable, |
+ &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node, |
+ *flow_table->type->params); |
+ rhashtable_remove_fast(&flow_table->rhashtable, |
+ &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node, |
+ *flow_table->type->params); |
+ |
+ e = container_of(flow, struct flow_offload_entry, flow); |
+ kfree_rcu(e, rcu_head); |
+} |
+EXPORT_SYMBOL_GPL(flow_offload_del); |
+ |
+struct flow_offload_tuple_rhash * |
+flow_offload_lookup(struct nf_flowtable *flow_table, |
+ struct flow_offload_tuple *tuple) |
+{ |
+ return rhashtable_lookup_fast(&flow_table->rhashtable, tuple, |
+ *flow_table->type->params); |
+} |
+EXPORT_SYMBOL_GPL(flow_offload_lookup); |
+ |
+static void nf_flow_release_ct(const struct flow_offload *flow) |
+{ |
+ struct flow_offload_entry *e; |
+ |
+ e = container_of(flow, struct flow_offload_entry, flow); |
+ nf_ct_delete(e->ct, 0, 0); |
+ nf_ct_put(e->ct); |
+} |
+ |
+int nf_flow_table_iterate(struct nf_flowtable *flow_table, |
+ void (*iter)(struct flow_offload *flow, void *data), |
+ void *data) |
+{ |
+ struct flow_offload_tuple_rhash *tuplehash; |
+ struct rhashtable_iter hti; |
+ struct flow_offload *flow; |
+ int err; |
+ |
+ err = rhashtable_walk_init(&flow_table->rhashtable, &hti, GFP_KERNEL); |
+ if (err) |
+ return err; |
+ |
+ rhashtable_walk_start(&hti); |
+ |
+ while ((tuplehash = rhashtable_walk_next(&hti))) { |
+ if (IS_ERR(tuplehash)) { |
+ err = PTR_ERR(tuplehash); |
+ if (err != -EAGAIN) |
+ goto out; |
+ |
+ continue; |
+ } |
+ if (tuplehash->tuple.dir) |
+ continue; |
+ |
+ flow = container_of(tuplehash, struct flow_offload, tuplehash[0]); |
+ |
+ iter(flow, data); |
+ } |
+out: |
+ rhashtable_walk_stop(&hti); |
+ rhashtable_walk_exit(&hti); |
+ |
+ return err; |
+} |
+EXPORT_SYMBOL_GPL(nf_flow_table_iterate); |
+ |
+static inline bool nf_flow_has_expired(const struct flow_offload *flow) |
+{ |
+ return (__s32)(flow->timeout - (u32)jiffies) <= 0; |
+} |
+ |
+static inline bool nf_flow_is_dying(const struct flow_offload *flow) |
+{ |
+ return flow->flags & FLOW_OFFLOAD_DYING; |
+} |
+ |
+void nf_flow_offload_work_gc(struct work_struct *work) |
+{ |
+ struct flow_offload_tuple_rhash *tuplehash; |
+ struct nf_flowtable *flow_table; |
+ struct rhashtable_iter hti; |
+ struct flow_offload *flow; |
+ int err; |
+ |
+ flow_table = container_of(work, struct nf_flowtable, gc_work.work); |
+ |
+ err = rhashtable_walk_init(&flow_table->rhashtable, &hti, GFP_KERNEL); |
+ if (err) |
+ goto schedule; |
+ |
+ rhashtable_walk_start(&hti); |
+ |
+ while ((tuplehash = rhashtable_walk_next(&hti))) { |
+ if (IS_ERR(tuplehash)) { |
+ err = PTR_ERR(tuplehash); |
+ if (err != -EAGAIN) |
+ goto out; |
+ |
+ continue; |
+ } |
+ if (tuplehash->tuple.dir) |
+ continue; |
+ |
+ flow = container_of(tuplehash, struct flow_offload, tuplehash[0]); |
+ |
+ if (nf_flow_has_expired(flow) || |
+ nf_flow_is_dying(flow)) { |
+ flow_offload_del(flow_table, flow); |
+ nf_flow_release_ct(flow); |
+ } |
+ } |
+out: |
+ rhashtable_walk_stop(&hti); |
+ rhashtable_walk_exit(&hti); |
+schedule: |
+ queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ); |
+} |
+EXPORT_SYMBOL_GPL(nf_flow_offload_work_gc); |
+ |
+static u32 flow_offload_hash(const void *data, u32 len, u32 seed) |
+{ |
+ const struct flow_offload_tuple *tuple = data; |
+ |
+ return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed); |
+} |
+ |
+static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed) |
+{ |
+ const struct flow_offload_tuple_rhash *tuplehash = data; |
+ |
+ return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed); |
+} |
+ |
+static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg, |
+ const void *ptr) |
+{ |
+ const struct flow_offload_tuple *tuple = arg->key; |
+ const struct flow_offload_tuple_rhash *x = ptr; |
+ |
+ if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir))) |
+ return 1; |
+ |
+ return 0; |
+} |
+ |
+const struct rhashtable_params nf_flow_offload_rhash_params = { |
+ .head_offset = offsetof(struct flow_offload_tuple_rhash, node), |
+ .hashfn = flow_offload_hash, |
+ .obj_hashfn = flow_offload_hash_obj, |
+ .obj_cmpfn = flow_offload_hash_cmp, |
+ .automatic_shrinking = true, |
+}; |
+EXPORT_SYMBOL_GPL(nf_flow_offload_rhash_params); |
+ |
+static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff, |
+ __be16 port, __be16 new_port) |
+{ |
+ 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_replace2(&tcph->check, skb, port, new_port, true); |
+ |
+ return 0; |
+} |
+ |
+static int nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff, |
+ __be16 port, __be16 new_port) |
+{ |
+ 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_replace2(&udph->check, skb, port, |
+ new_port, true); |
+ if (!udph->check) |
+ udph->check = CSUM_MANGLED_0; |
+ } |
+ |
+ return 0; |
+} |
+ |
+static int nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff, |
+ u8 protocol, __be16 port, __be16 new_port) |
+{ |
+ switch (protocol) { |
+ case IPPROTO_TCP: |
+ if (nf_flow_nat_port_tcp(skb, thoff, port, new_port) < 0) |
+ return NF_DROP; |
+ break; |
+ case IPPROTO_UDP: |
+ if (nf_flow_nat_port_udp(skb, thoff, port, new_port) < 0) |
+ return NF_DROP; |
+ break; |
+ } |
+ |
+ return 0; |
+} |
+ |
+int nf_flow_snat_port(const struct flow_offload *flow, |
+ struct sk_buff *skb, unsigned int thoff, |
+ u8 protocol, enum flow_offload_tuple_dir dir) |
+{ |
+ struct flow_ports *hdr; |
+ __be16 port, new_port; |
+ |
+ if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) || |
+ skb_try_make_writable(skb, thoff + sizeof(*hdr))) |
+ return -1; |
+ |
+ hdr = (void *)(skb_network_header(skb) + thoff); |
+ |
+ switch (dir) { |
+ case FLOW_OFFLOAD_DIR_ORIGINAL: |
+ port = hdr->source; |
+ new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port; |
+ hdr->source = new_port; |
+ break; |
+ case FLOW_OFFLOAD_DIR_REPLY: |
+ port = hdr->dest; |
+ new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port; |
+ hdr->dest = new_port; |
+ break; |
+ default: |
+ return -1; |
+ } |
+ |
+ return nf_flow_nat_port(skb, thoff, protocol, port, new_port); |
+} |
+EXPORT_SYMBOL_GPL(nf_flow_snat_port); |
+ |
+int nf_flow_dnat_port(const struct flow_offload *flow, |
+ struct sk_buff *skb, unsigned int thoff, |
+ u8 protocol, enum flow_offload_tuple_dir dir) |
+{ |
+ struct flow_ports *hdr; |
+ __be16 port, new_port; |
+ |
+ if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) || |
+ skb_try_make_writable(skb, thoff + sizeof(*hdr))) |
+ return -1; |
+ |
+ hdr = (void *)(skb_network_header(skb) + thoff); |
+ |
+ switch (dir) { |
+ case FLOW_OFFLOAD_DIR_ORIGINAL: |
+ port = hdr->dest; |
+ new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port; |
+ hdr->dest = new_port; |
+ break; |
+ case FLOW_OFFLOAD_DIR_REPLY: |
+ port = hdr->source; |
+ new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port; |
+ hdr->source = new_port; |
+ break; |
+ default: |
+ return -1; |
+ } |
+ |
+ return nf_flow_nat_port(skb, thoff, protocol, port, new_port); |
+} |
+EXPORT_SYMBOL_GPL(nf_flow_dnat_port); |
+ |
+MODULE_LICENSE("GPL"); |
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); |