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author | Felix Fietkau <nbd@nbd.name> | 2018-02-26 10:15:15 +0100 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-04-24 10:28:18 +0200 |
commit | a908fdec3dda2902edef18658d5cb39127d1051e (patch) | |
tree | 1ebfe3f995351f878c7728454014e534305af2ce /net/netfilter/nf_flow_table_ip.c | |
parent | 3aeb51d7e7b8dcc641a4238b162ed72fdc2c0b23 (diff) | |
download | linux-stable-a908fdec3dda2902edef18658d5cb39127d1051e.tar.gz linux-stable-a908fdec3dda2902edef18658d5cb39127d1051e.tar.bz2 linux-stable-a908fdec3dda2902edef18658d5cb39127d1051e.zip |
netfilter: nf_flow_table: move ipv6 offload hook code to nf_flow_table
Useful as preparation for adding iptables support for offload.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nf_flow_table_ip.c')
-rw-r--r-- | net/netfilter/nf_flow_table_ip.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 103263e0c7c2..dc570fb7641d 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -4,8 +4,11 @@ #include <linux/netfilter.h> #include <linux/rhashtable.h> #include <linux/ip.h> +#include <linux/ipv6.h> #include <linux/netdevice.h> #include <net/ip.h> +#include <net/ipv6.h> +#include <net/ip6_route.h> #include <net/neighbour.h> #include <net/netfilter/nf_flow_table.h> /* For layer 4 checksum field offset. */ @@ -242,3 +245,215 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, return NF_STOLEN; } EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook); + +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; +} + +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, flow->tuplehash[dir].tuple.mtu))) + 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; +} +EXPORT_SYMBOL_GPL(nf_flow_offload_ipv6_hook); |