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Message-Id: <4781b55b0b7498c574ace703a1481e3688e3f18d.1663946157.git.lucien.xin@gmail.com>
Date: Fri, 23 Sep 2022 11:28:27 -0400
From: Xin Long <lucien.xin@...il.com>
To: network dev <netdev@...r.kernel.org>
Cc: davem@...emloft.net, kuba@...nel.org,
Jamal Hadi Salim <jhs@...atatu.com>,
Cong Wang <xiyou.wangcong@...il.com>,
Jiri Pirko <jiri@...nulli.us>,
Marcelo Ricardo Leitner <marcelo.leitner@...il.com>,
Davide Caratti <dcaratti@...hat.com>,
Oz Shlomo <ozsh@...dia.com>, Paul Blakey <paulb@...dia.com>,
Ilya Maximets <i.maximets@....org>
Subject: [PATCH net-next 2/2] net: sched: add helper support in act_ct
This patch is to add helper support in act_ct for OVS actions=ct(alg=xxx)
offloading, which is corresponding to Commit cae3a2627520 ("openvswitch:
Allow attaching helpers to ct action") in OVS kernel part.
The difference is when adding TC actions family and proto cannot be got
from the filter/match, other than helper name in tb[TCA_CT_HELPER_NAME],
we also need to send the family in tb[TCA_CT_HELPER_FAMILY] and the
proto in tb[TCA_CT_HELPER_PROTO] to kernel.
Note when calling helper->help() in tcf_ct_act(), the packet will be
dropped if skb's family and proto do not match the helper's.
Reported-by: Ilya Maximets <i.maximets@....org>
Signed-off-by: Xin Long <lucien.xin@...il.com>
---
include/net/tc_act/tc_ct.h | 1 +
include/uapi/linux/tc_act/tc_ct.h | 3 +
net/sched/act_ct.c | 163 +++++++++++++++++++++++++++++-
3 files changed, 165 insertions(+), 2 deletions(-)
diff --git a/include/net/tc_act/tc_ct.h b/include/net/tc_act/tc_ct.h
index 8250d6f0a462..b24ea2d9400b 100644
--- a/include/net/tc_act/tc_ct.h
+++ b/include/net/tc_act/tc_ct.h
@@ -10,6 +10,7 @@
#include <net/netfilter/nf_conntrack_labels.h>
struct tcf_ct_params {
+ struct nf_conntrack_helper *helper;
struct nf_conn *tmpl;
u16 zone;
diff --git a/include/uapi/linux/tc_act/tc_ct.h b/include/uapi/linux/tc_act/tc_ct.h
index 5fb1d7ac1027..6c5200f0ed38 100644
--- a/include/uapi/linux/tc_act/tc_ct.h
+++ b/include/uapi/linux/tc_act/tc_ct.h
@@ -22,6 +22,9 @@ enum {
TCA_CT_NAT_PORT_MIN, /* be16 */
TCA_CT_NAT_PORT_MAX, /* be16 */
TCA_CT_PAD,
+ TCA_CT_HELPER_NAME, /* string */
+ TCA_CT_HELPER_FAMILY, /* u8 */
+ TCA_CT_HELPER_PROTO, /* u8 */
__TCA_CT_MAX
};
diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 193a460a9d7f..771cf72ee9e1 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -33,6 +33,7 @@
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
#include <net/netfilter/nf_conntrack_act_ct.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
#include <uapi/linux/netfilter/nf_nat.h>
static struct workqueue_struct *act_ct_wq;
@@ -832,6 +833,13 @@ static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
static void tcf_ct_params_free(struct tcf_ct_params *params)
{
+ if (params->helper) {
+#if IS_ENABLED(CONFIG_NF_NAT)
+ if (params->ct_action & TCA_CT_ACT_NAT)
+ nf_nat_helper_put(params->helper);
+#endif
+ nf_conntrack_helper_put(params->helper);
+ }
if (params->ct_ft)
tcf_ct_flow_table_put(params->ct_ft);
if (params->tmpl)
@@ -1022,6 +1030,69 @@ static int tcf_ct_act_nat(struct sk_buff *skb,
#endif
}
+static int tcf_ct_helper(struct sk_buff *skb, u8 family)
+{
+ const struct nf_conntrack_helper *helper;
+ const struct nf_conn_help *help;
+ enum ip_conntrack_info ctinfo;
+ unsigned int protoff;
+ struct nf_conn *ct;
+ u8 proto;
+ int err;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct || ctinfo == IP_CT_RELATED_REPLY)
+ return NF_ACCEPT;
+
+ help = nfct_help(ct);
+ if (!help)
+ return NF_ACCEPT;
+
+ helper = rcu_dereference(help->helper);
+ if (!helper)
+ return NF_ACCEPT;
+
+ if (helper->tuple.src.l3num != NFPROTO_UNSPEC &&
+ helper->tuple.src.l3num != family)
+ return NF_DROP;
+
+ switch (family) {
+ case NFPROTO_IPV4:
+ protoff = ip_hdrlen(skb);
+ proto = ip_hdr(skb)->protocol;
+ break;
+ case NFPROTO_IPV6: {
+ __be16 frag_off;
+ int ofs;
+
+ proto = ipv6_hdr(skb)->nexthdr;
+ ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto, &frag_off);
+ if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
+ pr_debug("proto header not found\n");
+ return NF_DROP;
+ }
+ protoff = ofs;
+ break;
+ }
+ default:
+ WARN_ONCE(1, "helper invoked on non-IP family!");
+ return NF_DROP;
+ }
+
+ if (helper->tuple.dst.protonum != proto)
+ return NF_DROP;
+
+ err = helper->help(skb, protoff, ct, ctinfo);
+ if (err != NF_ACCEPT)
+ return NF_DROP;
+
+ if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
+ !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
+ return NF_DROP;
+
+ return NF_ACCEPT;
+}
+
static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
@@ -1033,6 +1104,7 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
struct nf_hook_state state;
int nh_ofs, err, retval;
struct tcf_ct_params *p;
+ bool add_helper = false;
bool skip_add = false;
bool defrag = false;
struct nf_conn *ct;
@@ -1119,6 +1191,22 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
if (err != NF_ACCEPT)
goto drop;
+ if (commit && p->helper && !nfct_help(ct)) {
+ err = __nf_ct_try_assign_helper(ct, p->tmpl, GFP_ATOMIC);
+ if (err)
+ goto drop;
+ add_helper = true;
+ if (p->ct_action & TCA_CT_ACT_NAT && !nfct_seqadj(ct)) {
+ if (!nfct_seqadj_ext_add(ct))
+ return -EINVAL;
+ }
+ }
+
+ if (nf_ct_is_confirmed(ct) ? (!cached || add_helper) : commit) {
+ if (tcf_ct_helper(skb, family) != NF_ACCEPT)
+ goto drop;
+ }
+
if (commit) {
tcf_ct_act_set_mark(ct, p->mark, p->mark_mask);
tcf_ct_act_set_labels(ct, p->labels, p->labels_mask);
@@ -1167,6 +1255,9 @@ static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
[TCA_CT_NAT_IPV6_MAX] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
[TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 },
[TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 },
+ [TCA_CT_HELPER_NAME] = { .type = NLA_STRING, .len = NF_CT_HELPER_NAME_LEN },
+ [TCA_CT_HELPER_FAMILY] = { .type = NLA_U8 },
+ [TCA_CT_HELPER_PROTO] = { .type = NLA_U8 },
};
static int tcf_ct_fill_params_nat(struct tcf_ct_params *p,
@@ -1248,6 +1339,39 @@ static void tcf_ct_set_key_val(struct nlattr **tb,
nla_memcpy(mask, tb[mask_type], len);
}
+static int tcf_ct_add_helper(struct tcf_ct_params *p, const char *name, u8 family,
+ u8 proto, struct netlink_ext_ack *extack)
+{
+ struct nf_conntrack_helper *helper;
+ struct nf_conn_help *help;
+ int err;
+
+ helper = nf_conntrack_helper_try_module_get(name, family, proto);
+ if (!helper) {
+ NL_SET_ERR_MSG_MOD(extack, "Unknown helper");
+ return -EINVAL;
+ }
+
+ help = nf_ct_helper_ext_add(p->tmpl, GFP_KERNEL);
+ if (!help) {
+ nf_conntrack_helper_put(helper);
+ return -ENOMEM;
+ }
+#if IS_ENABLED(CONFIG_NF_NAT)
+ if (p->ct_action & TCA_CT_ACT_NAT) {
+ err = nf_nat_helper_try_module_get(name, family, proto);
+ if (err) {
+ nf_conntrack_helper_put(helper);
+ NL_SET_ERR_MSG_MOD(extack, "Failed to load NAT helper");
+ return err;
+ }
+ }
+#endif
+ rcu_assign_pointer(help->helper, helper);
+ p->helper = helper;
+ return 0;
+}
+
static int tcf_ct_fill_params(struct net *net,
struct tcf_ct_params *p,
struct tc_ct *parm,
@@ -1256,8 +1380,9 @@ static int tcf_ct_fill_params(struct net *net,
{
struct tc_ct_action_net *tn = net_generic(net, act_ct_ops.net_id);
struct nf_conntrack_zone zone;
+ int err, family, proto, len;
struct nf_conn *tmpl;
- int err;
+ char *name;
p->zone = NF_CT_DEFAULT_ZONE_ID;
@@ -1318,10 +1443,28 @@ static int tcf_ct_fill_params(struct net *net,
NL_SET_ERR_MSG_MOD(extack, "Failed to allocate conntrack template");
return -ENOMEM;
}
- __set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
p->tmpl = tmpl;
+ if (tb[TCA_CT_HELPER_NAME]) {
+ name = nla_data(tb[TCA_CT_HELPER_NAME]);
+ len = nla_len(tb[TCA_CT_HELPER_NAME]);
+ if (len > 16 || name[len - 1] != '\0') {
+ NL_SET_ERR_MSG_MOD(extack, "Failed to parse helper name.");
+ err = -EINVAL;
+ goto err;
+ }
+ family = tb[TCA_CT_HELPER_FAMILY] ? nla_get_u8(tb[TCA_CT_HELPER_FAMILY]) : AF_INET;
+ proto = tb[TCA_CT_HELPER_PROTO] ? nla_get_u8(tb[TCA_CT_HELPER_PROTO]) : IPPROTO_TCP;
+ err = tcf_ct_add_helper(p, name, family, proto, extack);
+ if (err)
+ goto err;
+ }
+ __set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
return 0;
+err:
+ nf_ct_put(p->tmpl);
+ p->tmpl = NULL;
+ return err;
}
static int tcf_ct_init(struct net *net, struct nlattr *nla,
@@ -1490,6 +1633,19 @@ static int tcf_ct_dump_nat(struct sk_buff *skb, struct tcf_ct_params *p)
return 0;
}
+static int tcf_ct_dump_helper(struct sk_buff *skb, struct nf_conntrack_helper *helper)
+{
+ if (!helper)
+ return 0;
+
+ if (nla_put_string(skb, TCA_CT_HELPER_NAME, helper->name) ||
+ nla_put_u8(skb, TCA_CT_HELPER_FAMILY, helper->tuple.src.l3num) ||
+ nla_put_u8(skb, TCA_CT_HELPER_PROTO, helper->tuple.dst.protonum))
+ return -1;
+
+ return 0;
+}
+
static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
@@ -1542,6 +1698,9 @@ static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a,
if (tcf_ct_dump_nat(skb, p))
goto nla_put_failure;
+ if (tcf_ct_dump_helper(skb, p->helper))
+ goto nla_put_failure;
+
skip_dump:
if (nla_put(skb, TCA_CT_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
--
2.31.1
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