netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.
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@strlen.de> Signed-off-by: Jack Ma <jack.ma@alliedtelesis.co.nz> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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d72133e628
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472a73e007
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@ -19,11 +19,21 @@ enum {
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XT_CONNMARK_RESTORE
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};
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enum {
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D_SHIFT_LEFT = 0,
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D_SHIFT_RIGHT,
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};
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struct xt_connmark_tginfo1 {
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__u32 ctmark, ctmask, nfmask;
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__u8 mode;
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};
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struct xt_connmark_tginfo2 {
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__u32 ctmark, ctmask, nfmask;
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__u8 shift_dir, shift_bits, mode;
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};
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struct xt_connmark_mtinfo1 {
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__u32 mark, mask;
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__u8 invert;
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@ -36,9 +36,10 @@ MODULE_ALIAS("ipt_connmark");
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MODULE_ALIAS("ip6t_connmark");
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static unsigned int
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connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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connmark_tg_shift(struct sk_buff *skb,
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const struct xt_connmark_tginfo1 *info,
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u8 shift_bits, u8 shift_dir)
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{
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const struct xt_connmark_tginfo1 *info = par->targinfo;
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enum ip_conntrack_info ctinfo;
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struct nf_conn *ct;
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u_int32_t newmark;
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@ -50,6 +51,10 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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switch (info->mode) {
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case XT_CONNMARK_SET:
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newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
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if (shift_dir == D_SHIFT_RIGHT)
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newmark >>= shift_bits;
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else
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newmark <<= shift_bits;
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if (ct->mark != newmark) {
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ct->mark = newmark;
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nf_conntrack_event_cache(IPCT_MARK, ct);
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@ -57,7 +62,11 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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break;
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case XT_CONNMARK_SAVE:
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newmark = (ct->mark & ~info->ctmask) ^
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(skb->mark & info->nfmask);
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(skb->mark & info->nfmask);
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if (shift_dir == D_SHIFT_RIGHT)
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newmark >>= shift_bits;
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else
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newmark <<= shift_bits;
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if (ct->mark != newmark) {
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ct->mark = newmark;
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nf_conntrack_event_cache(IPCT_MARK, ct);
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@ -65,14 +74,34 @@ connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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break;
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case XT_CONNMARK_RESTORE:
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newmark = (skb->mark & ~info->nfmask) ^
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(ct->mark & info->ctmask);
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(ct->mark & info->ctmask);
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if (shift_dir == D_SHIFT_RIGHT)
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newmark >>= shift_bits;
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else
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newmark <<= shift_bits;
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skb->mark = newmark;
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break;
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}
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return XT_CONTINUE;
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}
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static unsigned int
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connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_connmark_tginfo1 *info = par->targinfo;
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return connmark_tg_shift(skb, info, 0, 0);
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}
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static unsigned int
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connmark_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
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{
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const struct xt_connmark_tginfo2 *info = par->targinfo;
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return connmark_tg_shift(skb, (const struct xt_connmark_tginfo1 *)info,
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info->shift_bits, info->shift_dir);
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}
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static int connmark_tg_check(const struct xt_tgchk_param *par)
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{
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int ret;
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@ -119,15 +148,27 @@ static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
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nf_ct_netns_put(par->net, par->family);
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}
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static struct xt_target connmark_tg_reg __read_mostly = {
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.name = "CONNMARK",
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.revision = 1,
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.family = NFPROTO_UNSPEC,
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.checkentry = connmark_tg_check,
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.target = connmark_tg,
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.targetsize = sizeof(struct xt_connmark_tginfo1),
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.destroy = connmark_tg_destroy,
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.me = THIS_MODULE,
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static struct xt_target connmark_tg_reg[] __read_mostly = {
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{
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.name = "CONNMARK",
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.revision = 1,
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.family = NFPROTO_UNSPEC,
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.checkentry = connmark_tg_check,
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.target = connmark_tg,
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.targetsize = sizeof(struct xt_connmark_tginfo1),
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.destroy = connmark_tg_destroy,
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.me = THIS_MODULE,
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},
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{
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.name = "CONNMARK",
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.revision = 2,
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.family = NFPROTO_UNSPEC,
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.checkentry = connmark_tg_check,
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.target = connmark_tg_v2,
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.targetsize = sizeof(struct xt_connmark_tginfo2),
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.destroy = connmark_tg_destroy,
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.me = THIS_MODULE,
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}
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};
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static struct xt_match connmark_mt_reg __read_mostly = {
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@ -145,12 +186,14 @@ static int __init connmark_mt_init(void)
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{
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int ret;
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ret = xt_register_target(&connmark_tg_reg);
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ret = xt_register_targets(connmark_tg_reg,
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ARRAY_SIZE(connmark_tg_reg));
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if (ret < 0)
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return ret;
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ret = xt_register_match(&connmark_mt_reg);
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if (ret < 0) {
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xt_unregister_target(&connmark_tg_reg);
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xt_unregister_targets(connmark_tg_reg,
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ARRAY_SIZE(connmark_tg_reg));
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return ret;
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}
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return 0;
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@ -159,7 +202,7 @@ static int __init connmark_mt_init(void)
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static void __exit connmark_mt_exit(void)
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{
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xt_unregister_match(&connmark_mt_reg);
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xt_unregister_target(&connmark_tg_reg);
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xt_unregister_target(connmark_tg_reg);
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}
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module_init(connmark_mt_init);
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