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author | 2017-03-08 22:54:18 +0800 | |
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committer | 2017-03-13 13:30:28 +0100 | |
commit | 10596608c4d62cb8c1c2b806debcbd32fe657e71 (patch) | |
tree | 1b78903a75011a45b7b647096b1319aedb475d11 /net/netfilter/nft_ct.c | |
parent | netfilter: nft_set_bitmap: fetch the element key based on the set->klen (diff) | |
download | linux-10596608c4d62cb8c1c2b806debcbd32fe657e71.tar.gz linux-10596608c4d62cb8c1c2b806debcbd32fe657e71.tar.bz2 linux-10596608c4d62cb8c1c2b806debcbd32fe657e71.zip |
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 = ®s->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(®s->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>
Diffstat (limited to 'net/netfilter/nft_ct.c')
-rw-r--r-- | net/netfilter/nft_ct.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c index bf548a7a71ec..91585b5e5307 100644 --- a/net/netfilter/nft_ct.c +++ b/net/netfilter/nft_ct.c @@ -83,7 +83,7 @@ static void nft_ct_get_eval(const struct nft_expr *expr, switch (priv->key) { case NFT_CT_DIRECTION: - *dest = CTINFO2DIR(ctinfo); + nft_reg_store8(dest, CTINFO2DIR(ctinfo)); return; case NFT_CT_STATUS: *dest = ct->status; @@ -151,20 +151,22 @@ static void nft_ct_get_eval(const struct nft_expr *expr, 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; #ifdef CONFIG_NF_CONNTRACK_ZONES case NFT_CT_ZONE: { const struct nf_conntrack_zone *zone = nf_ct_zone(ct); + u16 zoneid; if (priv->dir < IP_CT_DIR_MAX) - *dest = nf_ct_zone_id(zone, priv->dir); + zoneid = nf_ct_zone_id(zone, priv->dir); else - *dest = zone->id; + zoneid = zone->id; + nft_reg_store16(dest, zoneid); return; } #endif @@ -183,10 +185,10 @@ static void nft_ct_get_eval(const struct nft_expr *expr, 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; @@ -205,7 +207,7 @@ static void nft_ct_set_zone_eval(const struct nft_expr *expr, const struct nft_ct *priv = nft_expr_priv(expr); struct sk_buff *skb = pkt->skb; enum ip_conntrack_info ctinfo; - u16 value = regs->data[priv->sreg]; + u16 value = nft_reg_load16(®s->data[priv->sreg]); struct nf_conn *ct; ct = nf_ct_get(skb, &ctinfo); |