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523 lines
14 KiB
523 lines
14 KiB
![]()
7 years ago
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From: Felix Fietkau <nbd@nbd.name>
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Date: Sat, 17 Feb 2018 11:49:44 +0100
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Subject: [PATCH] netfilter: nf_flow_table: move ipv4 offload hook code to
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nf_flow_table
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Allows some minor code sharing with the ipv6 hook code and is also
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useful as preparation for adding iptables support for offload
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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create mode 100644 net/netfilter/nf_flow_table_ip.c
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--- a/net/ipv4/netfilter/nf_flow_table_ipv4.c
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+++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c
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@@ -2,248 +2,8 @@
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netfilter.h>
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-#include <linux/rhashtable.h>
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-#include <linux/ip.h>
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-#include <linux/netdevice.h>
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-#include <net/ip.h>
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-#include <net/neighbour.h>
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#include <net/netfilter/nf_flow_table.h>
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#include <net/netfilter/nf_tables.h>
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-/* For layer 4 checksum field offset. */
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-#include <linux/tcp.h>
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-#include <linux/udp.h>
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-
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-static int nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff,
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- __be32 addr, __be32 new_addr)
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-{
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- struct tcphdr *tcph;
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-
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- if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) ||
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- skb_try_make_writable(skb, thoff + sizeof(*tcph)))
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- return -1;
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-
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- tcph = (void *)(skb_network_header(skb) + thoff);
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- inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr, true);
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-
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- return 0;
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-}
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-
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-static int nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff,
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- __be32 addr, __be32 new_addr)
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-{
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- struct udphdr *udph;
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-
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- if (!pskb_may_pull(skb, thoff + sizeof(*udph)) ||
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- skb_try_make_writable(skb, thoff + sizeof(*udph)))
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- return -1;
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-
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- udph = (void *)(skb_network_header(skb) + thoff);
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- if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
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- inet_proto_csum_replace4(&udph->check, skb, addr,
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- new_addr, true);
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- if (!udph->check)
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- udph->check = CSUM_MANGLED_0;
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- }
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-
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- return 0;
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-}
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-
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-static int nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph,
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- unsigned int thoff, __be32 addr,
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- __be32 new_addr)
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-{
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- switch (iph->protocol) {
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- case IPPROTO_TCP:
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- if (nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr) < 0)
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- return NF_DROP;
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- break;
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- case IPPROTO_UDP:
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- if (nf_flow_nat_ip_udp(skb, thoff, addr, new_addr) < 0)
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- return NF_DROP;
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- break;
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- }
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-
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- return 0;
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-}
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-
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-static int nf_flow_snat_ip(const struct flow_offload *flow, struct sk_buff *skb,
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- struct iphdr *iph, unsigned int thoff,
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- enum flow_offload_tuple_dir dir)
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-{
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- __be32 addr, new_addr;
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-
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- switch (dir) {
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- case FLOW_OFFLOAD_DIR_ORIGINAL:
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- addr = iph->saddr;
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- new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4.s_addr;
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- iph->saddr = new_addr;
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- break;
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- case FLOW_OFFLOAD_DIR_REPLY:
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- addr = iph->daddr;
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- new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4.s_addr;
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- iph->daddr = new_addr;
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- break;
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- default:
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- return -1;
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- }
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- csum_replace4(&iph->check, addr, new_addr);
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-
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- return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
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-}
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-
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-static int nf_flow_dnat_ip(const struct flow_offload *flow, struct sk_buff *skb,
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- struct iphdr *iph, unsigned int thoff,
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- enum flow_offload_tuple_dir dir)
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-{
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- __be32 addr, new_addr;
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-
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- switch (dir) {
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- case FLOW_OFFLOAD_DIR_ORIGINAL:
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- addr = iph->daddr;
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- new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4.s_addr;
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- iph->daddr = new_addr;
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- break;
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- case FLOW_OFFLOAD_DIR_REPLY:
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- addr = iph->saddr;
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- new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4.s_addr;
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- iph->saddr = new_addr;
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- break;
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- default:
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- return -1;
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- }
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-
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- return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
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-}
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-
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-static int nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb,
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- enum flow_offload_tuple_dir dir)
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-{
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- struct iphdr *iph = ip_hdr(skb);
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- unsigned int thoff = iph->ihl * 4;
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-
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- if (flow->flags & FLOW_OFFLOAD_SNAT &&
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- (nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
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- nf_flow_snat_ip(flow, skb, iph, thoff, dir) < 0))
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- return -1;
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- if (flow->flags & FLOW_OFFLOAD_DNAT &&
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- (nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
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- nf_flow_dnat_ip(flow, skb, iph, thoff, dir) < 0))
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- return -1;
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-
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- return 0;
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-}
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-
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-static bool ip_has_options(unsigned int thoff)
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-{
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- return thoff != sizeof(struct iphdr);
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-}
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-
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-static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
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- struct flow_offload_tuple *tuple)
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-{
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- struct flow_ports *ports;
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- unsigned int thoff;
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- struct iphdr *iph;
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-
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- if (!pskb_may_pull(skb, sizeof(*iph)))
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- return -1;
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-
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- iph = ip_hdr(skb);
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- thoff = iph->ihl * 4;
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-
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- if (ip_is_fragment(iph) ||
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- unlikely(ip_has_options(thoff)))
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- return -1;
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-
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- if (iph->protocol != IPPROTO_TCP &&
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- iph->protocol != IPPROTO_UDP)
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- return -1;
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-
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- thoff = iph->ihl * 4;
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- if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
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- return -1;
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-
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- ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
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-
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- tuple->src_v4.s_addr = iph->saddr;
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- tuple->dst_v4.s_addr = iph->daddr;
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- tuple->src_port = ports->source;
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- tuple->dst_port = ports->dest;
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- tuple->l3proto = AF_INET;
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- tuple->l4proto = iph->protocol;
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- tuple->iifidx = dev->ifindex;
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-
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- return 0;
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-}
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-
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-/* Based on ip_exceeds_mtu(). */
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-static bool nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
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-{
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- if (skb->len <= mtu)
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- return false;
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-
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- if ((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0)
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- return false;
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-
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- if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
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- return false;
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-
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- return true;
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-}
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-
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-unsigned int
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-nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
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- const struct nf_hook_state *state)
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-{
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- struct flow_offload_tuple_rhash *tuplehash;
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- struct nf_flowtable *flow_table = priv;
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- struct flow_offload_tuple tuple = {};
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- enum flow_offload_tuple_dir dir;
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- struct flow_offload *flow;
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- struct net_device *outdev;
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- const struct rtable *rt;
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- struct iphdr *iph;
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- __be32 nexthop;
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-
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- if (skb->protocol != htons(ETH_P_IP))
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- return NF_ACCEPT;
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-
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- if (nf_flow_tuple_ip(skb, state->in, &tuple) < 0)
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- return NF_ACCEPT;
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-
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- tuplehash = flow_offload_lookup(flow_table, &tuple);
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- if (tuplehash == NULL)
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- return NF_ACCEPT;
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-
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- outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.oifidx);
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- if (!outdev)
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- return NF_ACCEPT;
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-
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- dir = tuplehash->tuple.dir;
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- flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
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- rt = (const struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
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-
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- if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
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- return NF_ACCEPT;
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-
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- if (skb_try_make_writable(skb, sizeof(*iph)))
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- return NF_DROP;
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-
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- if (flow->flags & (FLOW_OFFLOAD_SNAT | FLOW_OFFLOAD_DNAT) &&
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- nf_flow_nat_ip(flow, skb, dir) < 0)
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- return NF_DROP;
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-
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- flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT;
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- iph = ip_hdr(skb);
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- ip_decrease_ttl(iph);
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-
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- skb->dev = outdev;
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- nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
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- neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
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-
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- return NF_STOLEN;
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-}
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-EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);
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static struct nf_flowtable_type flowtable_ipv4 = {
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.family = NFPROTO_IPV4,
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--- a/net/netfilter/Makefile
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+++ b/net/netfilter/Makefile
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@@ -113,7 +113,7 @@ obj-$(CONFIG_NFT_FWD_NETDEV) += nft_fwd_
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# flow table infrastructure
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obj-$(CONFIG_NF_FLOW_TABLE) += nf_flow_table.o
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-nf_flow_table-objs := nf_flow_table_core.o
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+nf_flow_table-objs := nf_flow_table_core.o nf_flow_table_ip.o
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obj-$(CONFIG_NF_FLOW_TABLE_INET) += nf_flow_table_inet.o
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--- /dev/null
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+++ b/net/netfilter/nf_flow_table_ip.c
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@@ -0,0 +1,245 @@
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+#include <linux/kernel.h>
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+#include <linux/init.h>
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+#include <linux/module.h>
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+#include <linux/netfilter.h>
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+#include <linux/rhashtable.h>
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+#include <linux/ip.h>
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+#include <linux/netdevice.h>
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+#include <net/ip.h>
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+#include <net/neighbour.h>
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+#include <net/netfilter/nf_flow_table.h>
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+/* For layer 4 checksum field offset. */
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+#include <linux/tcp.h>
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+#include <linux/udp.h>
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+
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+static int nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff,
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+ __be32 addr, __be32 new_addr)
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+{
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+ struct tcphdr *tcph;
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+
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+ if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) ||
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+ skb_try_make_writable(skb, thoff + sizeof(*tcph)))
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+ return -1;
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+
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+ tcph = (void *)(skb_network_header(skb) + thoff);
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+ inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr, true);
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+
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+ return 0;
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+}
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+
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+static int nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff,
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+ __be32 addr, __be32 new_addr)
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+{
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+ struct udphdr *udph;
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+
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+ if (!pskb_may_pull(skb, thoff + sizeof(*udph)) ||
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+ skb_try_make_writable(skb, thoff + sizeof(*udph)))
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+ return -1;
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+
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+ udph = (void *)(skb_network_header(skb) + thoff);
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+ if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
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+ inet_proto_csum_replace4(&udph->check, skb, addr,
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+ new_addr, true);
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+ if (!udph->check)
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+ udph->check = CSUM_MANGLED_0;
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+ }
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+
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+ return 0;
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+}
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+
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+static int nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph,
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+ unsigned int thoff, __be32 addr,
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+ __be32 new_addr)
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+{
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+ switch (iph->protocol) {
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+ case IPPROTO_TCP:
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+ if (nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr) < 0)
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+ return NF_DROP;
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+ break;
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+ case IPPROTO_UDP:
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+ if (nf_flow_nat_ip_udp(skb, thoff, addr, new_addr) < 0)
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+ return NF_DROP;
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+ break;
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+ }
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+
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+ return 0;
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+}
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+
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+static int nf_flow_snat_ip(const struct flow_offload *flow, struct sk_buff *skb,
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+ struct iphdr *iph, unsigned int thoff,
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+ enum flow_offload_tuple_dir dir)
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+{
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+ __be32 addr, new_addr;
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+
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+ switch (dir) {
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+ case FLOW_OFFLOAD_DIR_ORIGINAL:
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+ addr = iph->saddr;
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+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4.s_addr;
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+ iph->saddr = new_addr;
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+ break;
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+ case FLOW_OFFLOAD_DIR_REPLY:
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+ addr = iph->daddr;
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+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4.s_addr;
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+ iph->daddr = new_addr;
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+ break;
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+ default:
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+ return -1;
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+ }
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+ csum_replace4(&iph->check, addr, new_addr);
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+
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+ return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
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+}
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+
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+static int nf_flow_dnat_ip(const struct flow_offload *flow, struct sk_buff *skb,
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+ struct iphdr *iph, unsigned int thoff,
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+ enum flow_offload_tuple_dir dir)
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+{
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+ __be32 addr, new_addr;
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+
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+ switch (dir) {
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+ case FLOW_OFFLOAD_DIR_ORIGINAL:
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+ addr = iph->daddr;
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+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4.s_addr;
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+ iph->daddr = new_addr;
|
||
|
+ break;
|
||
|
+ case FLOW_OFFLOAD_DIR_REPLY:
|
||
|
+ addr = iph->saddr;
|
||
|
+ new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4.s_addr;
|
||
|
+ iph->saddr = new_addr;
|
||
|
+ break;
|
||
|
+ default:
|
||
|
+ return -1;
|
||
|
+ }
|
||
|
+
|
||
|
+ return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
|
||
|
+}
|
||
|
+
|
||
|
+static int nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb,
|
||
|
+ enum flow_offload_tuple_dir dir)
|
||
|
+{
|
||
|
+ struct iphdr *iph = ip_hdr(skb);
|
||
|
+ unsigned int thoff = iph->ihl * 4;
|
||
|
+
|
||
|
+ if (flow->flags & FLOW_OFFLOAD_SNAT &&
|
||
|
+ (nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
|
||
|
+ nf_flow_snat_ip(flow, skb, iph, thoff, dir) < 0))
|
||
|
+ return -1;
|
||
|
+ if (flow->flags & FLOW_OFFLOAD_DNAT &&
|
||
|
+ (nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
|
||
|
+ nf_flow_dnat_ip(flow, skb, iph, thoff, dir) < 0))
|
||
|
+ return -1;
|
||
|
+
|
||
|
+ return 0;
|
||
|
+}
|
||
|
+
|
||
|
+static bool ip_has_options(unsigned int thoff)
|
||
|
+{
|
||
|
+ return thoff != sizeof(struct iphdr);
|
||
|
+}
|
||
|
+
|
||
|
+static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
|
||
|
+ struct flow_offload_tuple *tuple)
|
||
|
+{
|
||
|
+ struct flow_ports *ports;
|
||
|
+ unsigned int thoff;
|
||
|
+ struct iphdr *iph;
|
||
|
+
|
||
|
+ if (!pskb_may_pull(skb, sizeof(*iph)))
|
||
|
+ return -1;
|
||
|
+
|
||
|
+ iph = ip_hdr(skb);
|
||
|
+ thoff = iph->ihl * 4;
|
||
|
+
|
||
|
+ if (ip_is_fragment(iph) ||
|
||
|
+ unlikely(ip_has_options(thoff)))
|
||
|
+ return -1;
|
||
|
+
|
||
|
+ if (iph->protocol != IPPROTO_TCP &&
|
||
|
+ iph->protocol != IPPROTO_UDP)
|
||
|
+ return -1;
|
||
|
+
|
||
|
+ thoff = iph->ihl * 4;
|
||
|
+ if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
|
||
|
+ return -1;
|
||
|
+
|
||
|
+ ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
|
||
|
+
|
||
|
+ tuple->src_v4.s_addr = iph->saddr;
|
||
|
+ tuple->dst_v4.s_addr = iph->daddr;
|
||
|
+ tuple->src_port = ports->source;
|
||
|
+ tuple->dst_port = ports->dest;
|
||
|
+ tuple->l3proto = AF_INET;
|
||
|
+ tuple->l4proto = iph->protocol;
|
||
|
+ 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 ((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0)
|
||
|
+ return false;
|
||
|
+
|
||
|
+ if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
|
||
|
+ return false;
|
||
|
+
|
||
|
+ return true;
|
||
|
+}
|
||
|
+
|
||
|
+unsigned int
|
||
|
+nf_flow_offload_ip_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;
|
||
|
+ const struct rtable *rt;
|
||
|
+ struct iphdr *iph;
|
||
|
+ __be32 nexthop;
|
||
|
+
|
||
|
+ if (skb->protocol != htons(ETH_P_IP))
|
||
|
+ return NF_ACCEPT;
|
||
|
+
|
||
|
+ if (nf_flow_tuple_ip(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 = (const struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
|
||
|
+
|
||
|
+ if (unlikely(nf_flow_exceeds_mtu(skb, flow->tuplehash[dir].tuple.mtu)))
|
||
|
+ return NF_ACCEPT;
|
||
|
+
|
||
|
+ if (skb_try_make_writable(skb, sizeof(*iph)))
|
||
|
+ return NF_DROP;
|
||
|
+
|
||
|
+ if (flow->flags & (FLOW_OFFLOAD_SNAT | FLOW_OFFLOAD_DNAT) &&
|
||
|
+ nf_flow_nat_ip(flow, skb, dir) < 0)
|
||
|
+ return NF_DROP;
|
||
|
+
|
||
|
+ flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT;
|
||
|
+ iph = ip_hdr(skb);
|
||
|
+ ip_decrease_ttl(iph);
|
||
|
+
|
||
|
+ skb->dev = outdev;
|
||
|
+ nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
|
||
|
+ neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
|
||
|
+
|
||
|
+ return NF_STOLEN;
|
||
|
+}
|
||
|
+EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);
|