From: Jack Ma <jack.ma@xxxxxxxxxxxxxxxxxxx>
This patch introduces a new feature that allows bitshifting (left
and right) operations to co-operate with existing iptables options.
Reviewed-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Jack Ma <jack.ma@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/uapi/linux/netfilter/xt_connmark.h | 10 ++++
net/netfilter/xt_connmark.c | 77 +++++++++++++++++++++++-------
2 files changed, 70 insertions(+), 17 deletions(-)
diff --git a/include/uapi/linux/netfilter/xt_connmark.h b/include/uapi/linux/netfilter/xt_connmark.h
index 408a9654f05c..1aa5c955ee1e 100644
--- a/include/uapi/linux/netfilter/xt_connmark.h
+++ b/include/uapi/linux/netfilter/xt_connmark.h
@@ -19,11 +19,21 @@ enum {
XT_CONNMARK_RESTORE
};
+enum {
+ D_SHIFT_LEFT = 0,
+ D_SHIFT_RIGHT,
+};
+
struct xt_connmark_tginfo1 {
__u32 ctmark, ctmask, nfmask;
__u8 mode;
};
+struct xt_connmark_tginfo2 {
+ __u32 ctmark, ctmask, nfmask;
+ __u8 shift_dir, shift_bits, mode;
+};
+
struct xt_connmark_mtinfo1 {
__u32 mark, mask;
__u8 invert;
diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index 809639ce6f5a..773da82190dc 100644
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -36,9 +36,10 @@ MODULE_ALIAS("ipt_connmark");
MODULE_ALIAS("ip6t_connmark");
static unsigned int
-connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
+connmark_tg_shift(struct sk_buff *skb,
+ const struct xt_connmark_tginfo1 *info,
+ u8 shift_bits, u8 shift_dir)
{
- const struct xt_connmark_tginfo1 *info = par->targinfo;
enum ip_conntrack_info ctinfo;
struct nf_conn *ct;
u_int32_t newmark;
@@ -50,6 +51,10 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
switch (info->mode) {
case XT_CONNMARK_SET:
newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
+ if (shift_dir == D_SHIFT_RIGHT)
+ newmark >>= shift_bits;
+ else
+ newmark <<= shift_bits;
if (ct->mark != newmark) {
ct->mark = newmark;
nf_conntrack_event_cache(IPCT_MARK, ct);
@@ -57,7 +62,11 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
break;
case XT_CONNMARK_SAVE:
newmark = (ct->mark & ~info->ctmask) ^
- (skb->mark & info->nfmask);
+ (skb->mark & info->nfmask);
+ if (shift_dir == D_SHIFT_RIGHT)
+ newmark >>= shift_bits;
+ else
+ newmark <<= shift_bits;
if (ct->mark != newmark) {
ct->mark = newmark;
nf_conntrack_event_cache(IPCT_MARK, ct);
@@ -65,14 +74,34 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
break;
case XT_CONNMARK_RESTORE:
newmark = (skb->mark & ~info->nfmask) ^
- (ct->mark & info->ctmask);
+ (ct->mark & info->ctmask);
+ if (shift_dir == D_SHIFT_RIGHT)
+ newmark >>= shift_bits;
+ else
+ newmark <<= shift_bits;
skb->mark = newmark;
break;
}
-
return XT_CONTINUE;
}
+static unsigned int
+connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct xt_connmark_tginfo1 *info = par->targinfo;
+
+ return connmark_tg_shift(skb, info, 0, 0);
+}
+
+static unsigned int
+connmark_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
+{
+ const struct xt_connmark_tginfo2 *info = par->targinfo;
+
+ return connmark_tg_shift(skb, (const struct xt_connmark_tginfo1 *)info,
+ info->shift_bits, info->shift_dir);
+}
+
static int connmark_tg_check(const struct xt_tgchk_param *par)
{
int ret;
@@ -119,15 +148,27 @@ static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
nf_ct_netns_put(par->net, par->family);
}
-static struct xt_target connmark_tg_reg __read_mostly = {
- .name = "CONNMARK",
- .revision = 1,
- .family = NFPROTO_UNSPEC,
- .checkentry = connmark_tg_check,
- .target = connmark_tg,
- .targetsize = sizeof(struct xt_connmark_tginfo1),
- .destroy = connmark_tg_destroy,
- .me = THIS_MODULE,
+static struct xt_target connmark_tg_reg[] __read_mostly = {
+ {
+ .name = "CONNMARK",
+ .revision = 1,
+ .family = NFPROTO_UNSPEC,
+ .checkentry = connmark_tg_check,
+ .target = connmark_tg,
+ .targetsize = sizeof(struct xt_connmark_tginfo1),
+ .destroy = connmark_tg_destroy,
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "CONNMARK",
+ .revision = 2,
+ .family = NFPROTO_UNSPEC,
+ .checkentry = connmark_tg_check,
+ .target = connmark_tg_v2,
+ .targetsize = sizeof(struct xt_connmark_tginfo2),
+ .destroy = connmark_tg_destroy,
+ .me = THIS_MODULE,
+ }
};
static struct xt_match connmark_mt_reg __read_mostly = {
@@ -145,12 +186,14 @@ static int __init connmark_mt_init(void)
{
int ret;
- ret = xt_register_target(&connmark_tg_reg);
+ ret = xt_register_targets(connmark_tg_reg,
+ ARRAY_SIZE(connmark_tg_reg));
if (ret < 0)
return ret;
ret = xt_register_match(&connmark_mt_reg);
if (ret < 0) {
- xt_unregister_target(&connmark_tg_reg);
+ xt_unregister_targets(connmark_tg_reg,
+ ARRAY_SIZE(connmark_tg_reg));
return ret;
}
return 0;
@@ -159,7 +202,7 @@ static int __init connmark_mt_init(void)
static void __exit connmark_mt_exit(void)
{
xt_unregister_match(&connmark_mt_reg);
- xt_unregister_target(&connmark_tg_reg);
+ xt_unregister_target(connmark_tg_reg);
}
module_init(connmark_mt_init);
--
2.11.0
--
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