#include <linux/kernel.h>
#include <linux/if_vlan.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nft_meta.h>
#include <net/netfilter/nf_tables_offload.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <net/gre.h>
#include <net/geneve.h>
#include <net/ip.h>
#include <linux/icmpv6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
struct nft_inner_tun_ctx_locked {
struct nft_inner_tun_ctx ctx;
local_lock_t bh_lock;
};
static DEFINE_PER_CPU(struct nft_inner_tun_ctx_locked, nft_pcpu_tun_ctx) = {
.bh_lock = INIT_LOCAL_LOCK(bh_lock),
};
struct __nft_expr {
const struct nft_expr_ops *ops;
union {
struct nft_payload payload;
struct nft_meta meta;
} __attribute__((aligned(__alignof__(u64))));
};
enum {
NFT_INNER_EXPR_PAYLOAD,
NFT_INNER_EXPR_META,
};
struct nft_inner {
u8 flags;
u8 hdrsize;
u8 type;
u8 expr_type;
struct __nft_expr expr;
};
static int nft_inner_parse_l2l3(const struct nft_inner *priv,
const struct nft_pktinfo *pkt,
struct nft_inner_tun_ctx *ctx, u32 off)
{
__be16 llproto, outer_llproto;
u32 nhoff, thoff;
if (priv->flags & NFT_INNER_LL) {
struct vlan_ethhdr *veth, _veth;
struct ethhdr *eth, _eth;
u32 hdrsize;
eth = skb_header_pointer(pkt->skb, off, sizeof(_eth), &_eth);
if (!eth)
return -1;
switch (eth->h_proto) {
case htons(ETH_P_IP):
case htons(ETH_P_IPV6):
llproto = eth->h_proto;
hdrsize = sizeof(_eth);
break;
case htons(ETH_P_8021Q):
veth = skb_header_pointer(pkt->skb, off, sizeof(_veth), &_veth);
if (!veth)
return -1;
outer_llproto = veth->h_vlan_encapsulated_proto;
llproto = veth->h_vlan_proto;
hdrsize = sizeof(_veth);
break;
default:
return -1;
}
ctx->inner_lloff = off;
ctx->flags |= NFT_PAYLOAD_CTX_INNER_LL;
off += hdrsize;
} else {
struct iphdr *iph;
u32 _version;
iph = skb_header_pointer(pkt->skb, off, sizeof(_version), &_version);
if (!iph)
return -1;
switch (iph->version) {
case 4:
llproto = htons(ETH_P_IP);
break;
case 6:
llproto = htons(ETH_P_IPV6);
break;
default:
return -1;
}
}
ctx->llproto = llproto;
if (llproto == htons(ETH_P_8021Q))
llproto = outer_llproto;
nhoff = off;
switch (llproto) {
case htons(ETH_P_IP): {
struct iphdr *iph, _iph;
iph = skb_header_pointer(pkt->skb, nhoff, sizeof(_iph), &_iph);
if (!iph)
return -1;
if (iph->ihl < 5 || iph->version != 4)
return -1;
ctx->inner_nhoff = nhoff;
ctx->flags |= NFT_PAYLOAD_CTX_INNER_NH;
thoff = nhoff + (iph->ihl * 4);
if ((ntohs(iph->frag_off) & IP_OFFSET) == 0) {
ctx->flags |= NFT_PAYLOAD_CTX_INNER_TH;
ctx->inner_thoff = thoff;
ctx->l4proto = iph->protocol;
}
}
break;
case htons(ETH_P_IPV6): {
struct ipv6hdr *ip6h, _ip6h;
int fh_flags = IP6_FH_F_AUTH;
unsigned short fragoff;
int l4proto;
ip6h = skb_header_pointer(pkt->skb, nhoff, sizeof(_ip6h), &_ip6h);
if (!ip6h)
return -1;
if (ip6h->version != 6)
return -1;
ctx->inner_nhoff = nhoff;
ctx->flags |= NFT_PAYLOAD_CTX_INNER_NH;
thoff = nhoff;
l4proto = ipv6_find_hdr(pkt->skb, &thoff, -1, &fragoff, &fh_flags);
if (l4proto < 0 || thoff > U16_MAX)
return -1;
if (fragoff == 0) {
thoff = nhoff + sizeof(_ip6h);
ctx->flags |= NFT_PAYLOAD_CTX_INNER_TH;
ctx->inner_thoff = thoff;
ctx->l4proto = l4proto;
}
}
break;
default:
return -1;
}
return 0;
}
static int nft_inner_parse_tunhdr(const struct nft_inner *priv,
const struct nft_pktinfo *pkt,
struct nft_inner_tun_ctx *ctx, u32 *off)
{
if (pkt->tprot == IPPROTO_GRE) {
ctx->inner_tunoff = pkt->thoff;
ctx->flags |= NFT_PAYLOAD_CTX_INNER_TUN;
return 0;
}
if (pkt->tprot != IPPROTO_UDP)
return -1;
ctx->inner_tunoff = *off;
ctx->flags |= NFT_PAYLOAD_CTX_INNER_TUN;
*off += priv->hdrsize;
switch (priv->type) {
case NFT_INNER_GENEVE: {
struct genevehdr *gnvh, _gnvh;
gnvh = skb_header_pointer(pkt->skb, pkt->inneroff,
sizeof(_gnvh), &_gnvh);
if (!gnvh)
return -1;
*off += gnvh->opt_len * 4;
}
break;
default:
break;
}
return 0;
}
static int nft_inner_parse(const struct nft_inner *priv,
struct nft_pktinfo *pkt,
struct nft_inner_tun_ctx *tun_ctx)
{
u32 off = pkt->inneroff;
if (priv->flags & NFT_INNER_HDRSIZE &&
nft_inner_parse_tunhdr(priv, pkt, tun_ctx, &off) < 0)
return -1;
if (priv->flags & (NFT_INNER_LL | NFT_INNER_NH)) {
if (nft_inner_parse_l2l3(priv, pkt, tun_ctx, off) < 0)
return -1;
} else if (priv->flags & NFT_INNER_TH) {
tun_ctx->inner_thoff = off;
tun_ctx->flags |= NFT_PAYLOAD_CTX_INNER_TH;
}
tun_ctx->type = priv->type;
tun_ctx->cookie = (unsigned long)pkt->skb;
pkt->flags |= NFT_PKTINFO_INNER_FULL;
return 0;
}
static bool nft_inner_restore_tun_ctx(const struct nft_pktinfo *pkt,
struct nft_inner_tun_ctx *tun_ctx)
{
struct nft_inner_tun_ctx *this_cpu_tun_ctx;
local_bh_disable();
local_lock_nested_bh(&nft_pcpu_tun_ctx.bh_lock);
this_cpu_tun_ctx = this_cpu_ptr(&nft_pcpu_tun_ctx.ctx);
if (this_cpu_tun_ctx->cookie != (unsigned long)pkt->skb) {
local_bh_enable();
local_unlock_nested_bh(&nft_pcpu_tun_ctx.bh_lock);
return false;
}
*tun_ctx = *this_cpu_tun_ctx;
local_unlock_nested_bh(&nft_pcpu_tun_ctx.bh_lock);
local_bh_enable();
return true;
}
static void nft_inner_save_tun_ctx(const struct nft_pktinfo *pkt,
const struct nft_inner_tun_ctx *tun_ctx)
{
struct nft_inner_tun_ctx *this_cpu_tun_ctx;
local_bh_disable();
local_lock_nested_bh(&nft_pcpu_tun_ctx.bh_lock);
this_cpu_tun_ctx = this_cpu_ptr(&nft_pcpu_tun_ctx.ctx);
if (this_cpu_tun_ctx->cookie != tun_ctx->cookie)
*this_cpu_tun_ctx = *tun_ctx;
local_unlock_nested_bh(&nft_pcpu_tun_ctx.bh_lock);
local_bh_enable();
}
static bool nft_inner_parse_needed(const struct nft_inner *priv,
const struct nft_pktinfo *pkt,
struct nft_inner_tun_ctx *tun_ctx)
{
if (!(pkt->flags & NFT_PKTINFO_INNER_FULL))
return true;
if (!nft_inner_restore_tun_ctx(pkt, tun_ctx))
return true;
if (priv->type != tun_ctx->type)
return true;
return false;
}
static void nft_inner_eval(const struct nft_expr *expr, struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_inner *priv = nft_expr_priv(expr);
struct nft_inner_tun_ctx tun_ctx = {};
if (nft_payload_inner_offset(pkt) < 0)
goto err;
if (nft_inner_parse_needed(priv, pkt, &tun_ctx) &&
nft_inner_parse(priv, (struct nft_pktinfo *)pkt, &tun_ctx) < 0)
goto err;
switch (priv->expr_type) {
case NFT_INNER_EXPR_PAYLOAD:
nft_payload_inner_eval((struct nft_expr *)&priv->expr, regs, pkt, &tun_ctx);
break;
case NFT_INNER_EXPR_META:
nft_meta_inner_eval((struct nft_expr *)&priv->expr, regs, pkt, &tun_ctx);
break;
default:
WARN_ON_ONCE(1);
goto err;
}
nft_inner_save_tun_ctx(pkt, &tun_ctx);
return;
err:
regs->verdict.code = NFT_BREAK;
}
static const struct nla_policy nft_inner_policy[NFTA_INNER_MAX + 1] = {
[NFTA_INNER_NUM] = { .type = NLA_U32 },
[NFTA_INNER_FLAGS] = { .type = NLA_U32 },
[NFTA_INNER_HDRSIZE] = { .type = NLA_U32 },
[NFTA_INNER_TYPE] = { .type = NLA_U32 },
[NFTA_INNER_EXPR] = { .type = NLA_NESTED },
};
struct nft_expr_info {
const struct nft_expr_ops *ops;
const struct nlattr *attr;
struct nlattr *tb[NFT_EXPR_MAXATTR + 1];
};
static int nft_inner_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_inner *priv = nft_expr_priv(expr);
u32 flags, hdrsize, type, num;
struct nft_expr_info expr_info;
int err;
if (!tb[NFTA_INNER_FLAGS] ||
!tb[NFTA_INNER_NUM] ||
!tb[NFTA_INNER_HDRSIZE] ||
!tb[NFTA_INNER_TYPE] ||
!tb[NFTA_INNER_EXPR])
return -EINVAL;
flags = ntohl(nla_get_be32(tb[NFTA_INNER_FLAGS]));
if (flags & ~NFT_INNER_MASK)
return -EOPNOTSUPP;
num = ntohl(nla_get_be32(tb[NFTA_INNER_NUM]));
if (num != 0)
return -EOPNOTSUPP;
hdrsize = ntohl(nla_get_be32(tb[NFTA_INNER_HDRSIZE]));
type = ntohl(nla_get_be32(tb[NFTA_INNER_TYPE]));
if (type > U8_MAX)
return -EINVAL;
if (flags & NFT_INNER_HDRSIZE) {
if (hdrsize == 0 || hdrsize > 64)
return -EOPNOTSUPP;
}
priv->flags = flags;
priv->hdrsize = hdrsize;
priv->type = type;
err = nft_expr_inner_parse(ctx, tb[NFTA_INNER_EXPR], &expr_info);
if (err < 0)
return err;
priv->expr.ops = expr_info.ops;
if (!strcmp(expr_info.ops->type->name, "payload"))
priv->expr_type = NFT_INNER_EXPR_PAYLOAD;
else if (!strcmp(expr_info.ops->type->name, "meta"))
priv->expr_type = NFT_INNER_EXPR_META;
else
return -EINVAL;
err = expr_info.ops->init(ctx, (struct nft_expr *)&priv->expr,
(const struct nlattr * const*)expr_info.tb);
if (err < 0)
return err;
return 0;
}
static int nft_inner_dump(struct sk_buff *skb,
const struct nft_expr *expr, bool reset)
{
const struct nft_inner *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_INNER_NUM, htonl(0)) ||
nla_put_be32(skb, NFTA_INNER_TYPE, htonl(priv->type)) ||
nla_put_be32(skb, NFTA_INNER_FLAGS, htonl(priv->flags)) ||
nla_put_be32(skb, NFTA_INNER_HDRSIZE, htonl(priv->hdrsize)))
goto nla_put_failure;
if (nft_expr_dump(skb, NFTA_INNER_EXPR,
(struct nft_expr *)&priv->expr, reset) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static const struct nft_expr_ops nft_inner_ops = {
.type = &nft_inner_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_inner)),
.eval = nft_inner_eval,
.init = nft_inner_init,
.dump = nft_inner_dump,
};
struct nft_expr_type nft_inner_type __read_mostly = {
.name = "inner",
.ops = &nft_inner_ops,
.policy = nft_inner_policy,
.maxattr = NFTA_INNER_MAX,
.owner = THIS_MODULE,
};
