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kernel: backport fix for nftables on big Endian 

nftables 0.8.1 generates some new commands which will not work without
this on big endian systems. This patch is included in Linux 4.11 and
later.

My rule matching a TCP port was not working:
nft add rule ip foo bar ct state new tcp dport 22 accept

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
openwrt-18.06
Hauke Mehrtens 2018-01-20 20:14:47 +01:00
parent e787ad5c96
commit f9aca01a53
1 changed files with 323 additions and 0 deletions
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323
target/linux/generic/backport-4.9/092-netfilter-nf_tables-fix-mismatch-in-big-endian-syste.patch Normal file
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@ -0,0 +1,323 @@
From 0bc01df3df7a88258148518eb9ce7f88c16a6106 Mon Sep 17 00:00:00 2001
From: Liping Zhang <zlpnobody@gmail.com>
Date: Wed, 8 Mar 2017 22:54:18 +0800
Subject: netfilter: nf_tables: fix mismatch in big-endian system
Currently, there are two different methods to store an u16 integer to
the u32 data register. For example:
u32 *dest = &regs->data[priv->dreg];
1. *dest = 0; *(u16 *) dest = val_u16;
2. *dest = val_u16;
For method 1, the u16 value will be stored like this, either in
big-endian or little-endian system:
0 15 31
+-+-+-+-+-+-+-+-+-+-+-+-+
| Value | 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+
For method 2, in little-endian system, the u16 value will be the same
as listed above. But in big-endian system, the u16 value will be stored
like this:
0 15 31
+-+-+-+-+-+-+-+-+-+-+-+-+
| 0 | Value |
+-+-+-+-+-+-+-+-+-+-+-+-+
So later we use "memcmp(&regs->data[priv->sreg], data, 2);" to do
compare in nft_cmp, nft_lookup expr ..., method 2 will get the wrong
result in big-endian system, as 0~15 bits will always be zero.
For the similar reason, when loading an u16 value from the u32 data
register, we should use "*(u16 *) sreg;" instead of "(u16)*sreg;",
the 2nd method will get the wrong value in the big-endian system.
So introduce some wrapper functions to store/load an u8 or u16
integer to/from the u32 data register, and use them in the right
place.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/net/netfilter/nf_tables.h | 29 +++++++++++++++++++++++++
net/ipv4/netfilter/nft_masq_ipv4.c | 8 +++----
net/ipv4/netfilter/nft_redir_ipv4.c | 8 +++----
net/ipv6/netfilter/nft_masq_ipv6.c | 8 +++----
net/ipv6/netfilter/nft_redir_ipv6.c | 8 +++----
net/netfilter/nft_ct.c | 10 ++++-----
net/netfilter/nft_meta.c | 42 +++++++++++++++++++------------------
net/netfilter/nft_nat.c | 8 +++----
8 files changed, 76 insertions(+), 45 deletions(-)
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -87,6 +87,35 @@ struct nft_regs {
};
};
+/* Store/load an u16 or u8 integer to/from the u32 data register.
+ *
+ * Note, when using concatenations, register allocation happens at 32-bit
+ * level. So for store instruction, pad the rest part with zero to avoid
+ * garbage values.
+ */
+
+static inline void nft_reg_store16(u32 *dreg, u16 val)
+{
+ *dreg = 0;
+ *(u16 *)dreg = val;
+}
+
+static inline void nft_reg_store8(u32 *dreg, u8 val)
+{
+ *dreg = 0;
+ *(u8 *)dreg = val;
+}
+
+static inline u16 nft_reg_load16(u32 *sreg)
+{
+ return *(u16 *)sreg;
+}
+
+static inline u8 nft_reg_load8(u32 *sreg)
+{
+ return *(u8 *)sreg;
+}
+
static inline void nft_data_copy(u32 *dst, const struct nft_data *src,
unsigned int len)
{
--- a/net/ipv4/netfilter/nft_masq_ipv4.c
+++ b/net/ipv4/netfilter/nft_masq_ipv4.c
@@ -26,10 +26,10 @@ static void nft_masq_ipv4_eval(const str
memset(&range, 0, sizeof(range));
range.flags = priv->flags;
if (priv->sreg_proto_min) {
- range.min_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_min];
- range.max_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_max];
+ range.min_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_min]);
+ range.max_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_max]);
}
regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, pkt->hook,
&range, pkt->out);
--- a/net/ipv4/netfilter/nft_redir_ipv4.c
+++ b/net/ipv4/netfilter/nft_redir_ipv4.c
@@ -26,10 +26,10 @@ static void nft_redir_ipv4_eval(const st
memset(&mr, 0, sizeof(mr));
if (priv->sreg_proto_min) {
- mr.range[0].min.all =
- *(__be16 *)&regs->data[priv->sreg_proto_min];
- mr.range[0].max.all =
- *(__be16 *)&regs->data[priv->sreg_proto_max];
+ mr.range[0].min.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_min]);
+ mr.range[0].max.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_max]);
mr.range[0].flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
}
--- a/net/ipv6/netfilter/nft_masq_ipv6.c
+++ b/net/ipv6/netfilter/nft_masq_ipv6.c
@@ -27,10 +27,10 @@ static void nft_masq_ipv6_eval(const str
memset(&range, 0, sizeof(range));
range.flags = priv->flags;
if (priv->sreg_proto_min) {
- range.min_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_min];
- range.max_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_max];
+ range.min_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_min]);
+ range.max_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_max]);
}
regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range, pkt->out);
}
--- a/net/ipv6/netfilter/nft_redir_ipv6.c
+++ b/net/ipv6/netfilter/nft_redir_ipv6.c
@@ -26,10 +26,10 @@ static void nft_redir_ipv6_eval(const st
memset(&range, 0, sizeof(range));
if (priv->sreg_proto_min) {
- range.min_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_min],
- range.max_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_max],
+ range.min_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_min]);
+ range.max_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_max]);
range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
}
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -77,7 +77,7 @@ static void nft_ct_get_eval(const struct
switch (priv->key) {
case NFT_CT_DIRECTION:
- *dest = CTINFO2DIR(ctinfo);
+ nft_reg_store8(dest, CTINFO2DIR(ctinfo));
return;
case NFT_CT_STATUS:
*dest = ct->status;
@@ -129,10 +129,10 @@ static void nft_ct_get_eval(const struct
return;
}
case NFT_CT_L3PROTOCOL:
- *dest = nf_ct_l3num(ct);
+ nft_reg_store8(dest, nf_ct_l3num(ct));
return;
case NFT_CT_PROTOCOL:
- *dest = nf_ct_protonum(ct);
+ nft_reg_store8(dest, nf_ct_protonum(ct));
return;
default:
break;
@@ -149,10 +149,10 @@ static void nft_ct_get_eval(const struct
nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
return;
case NFT_CT_PROTO_SRC:
- *dest = (__force __u16)tuple->src.u.all;
+ nft_reg_store16(dest, (__force u16)tuple->src.u.all);
return;
case NFT_CT_PROTO_DST:
- *dest = (__force __u16)tuple->dst.u.all;
+ nft_reg_store16(dest, (__force u16)tuple->dst.u.all);
return;
default:
break;
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -45,16 +45,15 @@ void nft_meta_get_eval(const struct nft_
*dest = skb->len;
break;
case NFT_META_PROTOCOL:
- *dest = 0;
- *(__be16 *)dest = skb->protocol;
+ nft_reg_store16(dest, (__force u16)skb->protocol);
break;
case NFT_META_NFPROTO:
- *dest = pkt->pf;
+ nft_reg_store8(dest, pkt->pf);
break;
case NFT_META_L4PROTO:
if (!pkt->tprot_set)
goto err;
- *dest = pkt->tprot;
+ nft_reg_store8(dest, pkt->tprot);
break;
case NFT_META_PRIORITY:
*dest = skb->priority;
@@ -85,14 +84,12 @@ void nft_meta_get_eval(const struct nft_
case NFT_META_IIFTYPE:
if (in == NULL)
goto err;
- *dest = 0;
- *(u16 *)dest = in->type;
+ nft_reg_store16(dest, in->type);
break;
case NFT_META_OIFTYPE:
if (out == NULL)
goto err;
- *dest = 0;
- *(u16 *)dest = out->type;
+ nft_reg_store16(dest, out->type);
break;
case NFT_META_SKUID:
sk = skb_to_full_sk(skb);
@@ -142,22 +139,22 @@ void nft_meta_get_eval(const struct nft_
#endif
case NFT_META_PKTTYPE:
if (skb->pkt_type != PACKET_LOOPBACK) {
- *dest = skb->pkt_type;
+ nft_reg_store8(dest, skb->pkt_type);
break;
}
switch (pkt->pf) {
case NFPROTO_IPV4:
if (ipv4_is_multicast(ip_hdr(skb)->daddr))
- *dest = PACKET_MULTICAST;
+ nft_reg_store8(dest, PACKET_MULTICAST);
else
- *dest = PACKET_BROADCAST;
+ nft_reg_store8(dest, PACKET_BROADCAST);
break;
case NFPROTO_IPV6:
if (ipv6_hdr(skb)->daddr.s6_addr[0] == 0xFF)
- *dest = PACKET_MULTICAST;
+ nft_reg_store8(dest, PACKET_MULTICAST);
else
- *dest = PACKET_BROADCAST;
+ nft_reg_store8(dest, PACKET_BROADCAST);
break;
case NFPROTO_NETDEV:
switch (skb->protocol) {
@@ -171,14 +168,14 @@ void nft_meta_get_eval(const struct nft_
goto err;
if (ipv4_is_multicast(iph->daddr))
- *dest = PACKET_MULTICAST;
+ nft_reg_store8(dest, PACKET_MULTICAST);
else
- *dest = PACKET_BROADCAST;
+ nft_reg_store8(dest, PACKET_BROADCAST);
break;
}
case htons(ETH_P_IPV6):
- *dest = PACKET_MULTICAST;
+ nft_reg_store8(dest, PACKET_MULTICAST);
break;
default:
WARN_ON_ONCE(1);
@@ -233,7 +230,9 @@ void nft_meta_set_eval(const struct nft_
{
const struct nft_meta *meta = nft_expr_priv(expr);
struct sk_buff *skb = pkt->skb;
- u32 value = regs->data[meta->sreg];
+ u32 *sreg = &regs->data[meta->sreg];
+ u32 value = *sreg;
+ u8 pkt_type;
switch (meta->key) {
case NFT_META_MARK:
@@ -243,9 +242,12 @@ void nft_meta_set_eval(const struct nft_
skb->priority = value;
break;
case NFT_META_PKTTYPE:
- if (skb->pkt_type != value &&
- skb_pkt_type_ok(value) && skb_pkt_type_ok(skb->pkt_type))
- skb->pkt_type = value;
+ pkt_type = nft_reg_load8(sreg);
+
+ if (skb->pkt_type != pkt_type &&
+ skb_pkt_type_ok(pkt_type) &&
+ skb_pkt_type_ok(skb->pkt_type))
+ skb->pkt_type = pkt_type;
break;
case NFT_META_NFTRACE:
skb->nf_trace = !!value;
--- a/net/netfilter/nft_nat.c
+++ b/net/netfilter/nft_nat.c
@@ -65,10 +65,10 @@ static void nft_nat_eval(const struct nf
}
if (priv->sreg_proto_min) {
- range.min_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_min];
- range.max_proto.all =
- *(__be16 *)&regs->data[priv->sreg_proto_max];
+ range.min_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_min]);
+ range.max_proto.all = (__force __be16)nft_reg_load16(
+ &regs->data[priv->sreg_proto_max]);
range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
}