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.

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/include/net/tc_act/tc_ct.h b/include/net/tc_act/tc_ct.h
index 8250d6f..b24ea2d 100644 (file)
--- 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 5fb1d7a..6c5200f 100644 (file)
--- 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 193a460..da0b7f6 100644 (file)
--- 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;
@@ -655,7 +656,7 @@ struct tc_ct_action_net {
 
 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
 static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
-                                  u16 zone_id, bool force)
+                                  struct tcf_ct_params *p)
 {
        enum ip_conntrack_info ctinfo;
        struct nf_conn *ct;
@@ -665,11 +666,19 @@ static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
                return false;
        if (!net_eq(net, read_pnet(&ct->ct_net)))
                goto drop_ct;
-       if (nf_ct_zone(ct)->id != zone_id)
+       if (nf_ct_zone(ct)->id != p->zone)
                goto drop_ct;
+       if (p->helper) {
+               struct nf_conn_help *help;
+
+               help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
+               if (help && rcu_access_pointer(help->helper) != p->helper)
+                       goto drop_ct;
+       }
 
        /* Force conntrack entry direction. */
-       if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
+       if ((p->ct_action & TCA_CT_ACT_FORCE) &&
+           CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
                if (nf_ct_is_confirmed(ct))
                        nf_ct_kill(ct);
 
@@ -832,6 +841,13 @@ out_free:
 
 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)
@@ -1026,13 +1042,14 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
                      struct tcf_result *res)
 {
        struct net *net = dev_net(skb->dev);
-       bool cached, commit, clear, force;
        enum ip_conntrack_info ctinfo;
        struct tcf_ct *c = to_ct(a);
        struct nf_conn *tmpl = NULL;
        struct nf_hook_state state;
+       bool cached, commit, clear;
        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;
@@ -1043,7 +1060,6 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
        retval = READ_ONCE(c->tcf_action);
        commit = p->ct_action & TCA_CT_ACT_COMMIT;
        clear = p->ct_action & TCA_CT_ACT_CLEAR;
-       force = p->ct_action & TCA_CT_ACT_FORCE;
        tmpl = p->tmpl;
 
        tcf_lastuse_update(&c->tcf_tm);
@@ -1086,7 +1102,7 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
         * actually run the packet through conntrack twice unless it's for a
         * different zone.
         */
-       cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force);
+       cached = tcf_ct_skb_nfct_cached(net, skb, p);
        if (!cached) {
                if (tcf_ct_flow_table_lookup(p, skb, family)) {
                        skip_add = true;
@@ -1119,6 +1135,22 @@ do_nat:
        if (err != NF_ACCEPT)
                goto drop;
 
+       if (!nf_ct_is_confirmed(ct) && 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))
+                               goto drop;
+               }
+       }
+
+       if (nf_ct_is_confirmed(ct) ? ((!cached && !skip_add) || add_helper) : commit) {
+               if (nf_ct_helper(skb, ct, ctinfo, 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 +1199,9 @@ 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,
@@ -1256,8 +1291,9 @@ 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 +1354,31 @@ 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 = nf_ct_add_helper(tmpl, name, family, proto,
+                                      p->ct_action & TCA_CT_ACT_NAT, &p->helper);
+               if (err) {
+                       NL_SET_ERR_MSG_MOD(extack, "Failed to add helper");
+                       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 +1547,19 @@ 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 +1612,9 @@ 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;