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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-12-14 12:15:49 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2016-12-14 23:39:11 +0100 |
| commit | 053d20f5712529016eae10356e0dea9b360325bd (patch) | |
| tree | 9a023b68011891b0bb3b8f94d2d786735c6ae35b /net | |
| parent | 3e38df136e453aa69eb4472108ebce2fb00b1ba6 (diff) | |
| download | linux-053d20f5712529016eae10356e0dea9b360325bd.tar.gz linux-053d20f5712529016eae10356e0dea9b360325bd.tar.bz2 linux-053d20f5712529016eae10356e0dea9b360325bd.zip | |
netfilter: nft_payload: mangle ckecksum if NFT_PAYLOAD_L4CSUM_PSEUDOHDR is set
If the NFT_PAYLOAD_L4CSUM_PSEUDOHDR flag is set, then mangle layer 4
checksum. This should not depend on csum_type NFT_PAYLOAD_CSUM_INET
since IPv6 header has no checksum field, but still an update of any of
the pseudoheader fields may trigger a layer 4 checksum update.
Fixes: 1814096980bb ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_payload.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 36d2b1096546..7d699bbd45b0 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -250,6 +250,22 @@ static int nft_payload_l4csum_update(const struct nft_pktinfo *pkt, return 0; } +static int nft_payload_csum_inet(struct sk_buff *skb, const u32 *src, + __wsum fsum, __wsum tsum, int csum_offset) +{ + __sum16 sum; + + if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) + return -1; + + nft_csum_replace(&sum, fsum, tsum); + if (!skb_make_writable(skb, csum_offset + sizeof(sum)) || + skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) + return -1; + + return 0; +} + static void nft_payload_set_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) @@ -259,7 +275,6 @@ static void nft_payload_set_eval(const struct nft_expr *expr, const u32 *src = ®s->data[priv->sreg]; int offset, csum_offset; __wsum fsum, tsum; - __sum16 sum; switch (priv->base) { case NFT_PAYLOAD_LL_HEADER: @@ -282,18 +297,14 @@ static void nft_payload_set_eval(const struct nft_expr *expr, csum_offset = offset + priv->csum_offset; offset += priv->offset; - if (priv->csum_type == NFT_PAYLOAD_CSUM_INET && + if ((priv->csum_type == NFT_PAYLOAD_CSUM_INET || priv->csum_flags) && (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER || skb->ip_summed != CHECKSUM_PARTIAL)) { - if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) - goto err; - fsum = skb_checksum(skb, offset, priv->len, 0); tsum = csum_partial(src, priv->len, 0); - nft_csum_replace(&sum, fsum, tsum); - if (!skb_make_writable(skb, csum_offset + sizeof(sum)) || - skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) + if (priv->csum_type == NFT_PAYLOAD_CSUM_INET && + nft_payload_csum_inet(skb, src, fsum, tsum, csum_offset)) goto err; if (priv->csum_flags && |