netdev-linux: Allow meter to work in tc software datapath when tc-policy is specified

Add tc action flags when adding police action to offload meter table.

There is a restriction that the flag of skip_sw/skip_hw should be same for
filter rule and the independent created tc actions the rule uses. In this
case, if we configure the tc-policy as skip_hw, filter rule will be created
with skip_hw flag and the police action according to meter table will have
no action flag, then flower rule will fail to add to tc kernel system.

To fix this issue, we will add tc action flag when adding police action to
offload a meter table, so it will allow meter table to work in tc software
datapath.

Fixes: 5c039ddc64 ("netdev-linux: Add functions to manipulate tc police action")
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Acked-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Simon Horman <simon.horman@corigine.com>

acinclude.m4

@@ -163,10 +163,10 @@ dnl Configure Linux tc compat.
 AC_DEFUN([OVS_CHECK_LINUX_TC], [
   AC_COMPILE_IFELSE([
     AC_LANG_PROGRAM([#include <linux/pkt_cls.h>], [
-        int x = TCA_POLICE_PKTRATE64;
+        int x = TCA_ACT_FLAGS_SKIP_HW;
     ])],
-    [AC_DEFINE([HAVE_TCA_POLICE_PKTRATE64], [1],
+    [AC_DEFINE([HAVE_TCA_ACT_FLAGS_SKIP_HW], [1],
-               [Define to 1 if TCA_POLICE_PKTRATE64 is available.])])
+               [Define to 1 if TCA_ACT_FLAGS_SKIP_HW is available.])])
 
   AC_CHECK_MEMBERS([struct tcf_t.firstuse], [], [], [#include <linux/pkt_cls.h>])
 

include/linux/pkt_cls.h

@@ -1,7 +1,7 @@
 #ifndef __LINUX_PKT_CLS_WRAPPER_H
 #define __LINUX_PKT_CLS_WRAPPER_H 1
 
-#if defined(__KERNEL__) || defined(HAVE_TCA_POLICE_PKTRATE64)
+#if defined(__KERNEL__) || defined(HAVE_TCA_ACT_FLAGS_SKIP_HW)
 #include_next <linux/pkt_cls.h>
 #else
 
@@ -21,9 +21,12 @@ enum {
 	__TCA_ACT_MAX
 };
 
-#define TCA_ACT_FLAGS_NO_PERCPU_STATS 1 /* Don't use percpu allocator for
+/* See other TCA_ACT_FLAGS_ * flags in include/net/act_api.h. */
-                                         * actions stats.
+#define TCA_ACT_FLAGS_NO_PERCPU_STATS (1 << 0) /* Don't use percpu allocator for
-                                         */
+						* actions stats.
+						*/
+#define TCA_ACT_FLAGS_SKIP_HW	(1 << 1) /* don't offload action to HW */
+#define TCA_ACT_FLAGS_SKIP_SW	(1 << 2) /* don't use action in SW */
 
 #define TCA_ACT_MAX __TCA_ACT_MAX
 #define TCA_OLD_COMPAT (TCA_ACT_MAX+1)

lib/netdev-linux.c

@@ -2623,10 +2623,17 @@ tc_matchall_fill_police(uint32_t kbits_rate, uint32_t kbits_burst)
 
 static void
 nl_msg_act_police_start_nest(struct ofpbuf *request, uint32_t prio,
-                             size_t *offset, size_t *act_offset)
+                             size_t *offset, size_t *act_offset,
+                             bool single_action)
 {
     *act_offset = nl_msg_start_nested(request, prio);
     nl_msg_put_string(request, TCA_ACT_KIND, "police");
+
+    /* If police action is added independently from filter, we need to
+     * add action flag according to tc-policy. */
+    if (single_action) {
+        nl_msg_put_act_tc_policy_flag(request);
+    }
     *offset = nl_msg_start_nested(request, TCA_ACT_OPTIONS);
 }
 
@@ -2642,7 +2649,7 @@ nl_msg_act_police_end_nest(struct ofpbuf *request, size_t offset,
 static void
 nl_msg_put_act_police(struct ofpbuf *request, struct tc_police *police,
                       uint64_t pkts_rate, uint64_t pkts_burst,
-                      uint32_t notexceed_act)
+                      uint32_t notexceed_act, bool single_action)
 {
     size_t offset, act_offset;
     uint32_t prio = 0;
@@ -2651,7 +2658,8 @@ nl_msg_put_act_police(struct ofpbuf *request, struct tc_police *police,
         return;
     }
 
-    nl_msg_act_police_start_nest(request, ++prio, &offset, &act_offset);
+    nl_msg_act_police_start_nest(request, ++prio, &offset, &act_offset,
+                                 single_action);
     if (police->rate.rate) {
         tc_put_rtab(request, TCA_POLICE_RATE, &police->rate);
     }
@@ -2698,7 +2706,7 @@ tc_add_matchall_policer(struct netdev *netdev, uint32_t kbits_rate,
     basic_offset = nl_msg_start_nested(&request, TCA_OPTIONS);
     action_offset = nl_msg_start_nested(&request, TCA_MATCHALL_ACT);
     nl_msg_put_act_police(&request, &pol_act, kpkts_rate * 1000,
-                          kpkts_burst * 1000, TC_ACT_UNSPEC);
+                          kpkts_burst * 1000, TC_ACT_UNSPEC, false);
     nl_msg_end_nested(&request, action_offset);
     nl_msg_end_nested(&request, basic_offset);
 
@@ -5667,7 +5675,7 @@ tc_add_policer(struct netdev *netdev, uint32_t kbits_rate,
     police_offset = nl_msg_start_nested(&request, TCA_BASIC_ACT);
     tc_policer_init(&tc_police, kbits_rate, kbits_burst);
     nl_msg_put_act_police(&request, &tc_police, kpkts_rate * 1000ULL,
-                          kpkts_burst * 1000ULL, TC_ACT_UNSPEC);
+                          kpkts_burst * 1000ULL, TC_ACT_UNSPEC, false);
     nl_msg_end_nested(&request, police_offset);
     nl_msg_end_nested(&request, basic_offset);
 
@@ -5702,7 +5710,7 @@ tc_add_policer_action(uint32_t index, uint32_t kbits_rate,
 
     offset = nl_msg_start_nested(&request, TCA_ACT_TAB);
     nl_msg_put_act_police(&request, &tc_police, pkts_rate, pkts_burst,
-                          TC_ACT_PIPE);
+                          TC_ACT_PIPE, true);
     nl_msg_end_nested(&request, offset);
 
     error = tc_transact(&request, NULL);

lib/tc.c

@@ -3810,3 +3810,24 @@ tc_set_policy(const char *policy)
 
     VLOG_INFO("tc: Using policy '%s'", policy);
 }
+
+void
+nl_msg_put_act_tc_policy_flag(struct ofpbuf *request)
+{
+    int flag = 0;
+
+    if (!request) {
+        return;
+    }
+
+    if (tc_policy == TC_POLICY_SKIP_HW) {
+        flag = TCA_ACT_FLAGS_SKIP_HW;
+    } else if (tc_policy == TC_POLICY_SKIP_SW) {
+        flag = TCA_ACT_FLAGS_SKIP_SW;
+    }
+
+    if (flag) {
+        struct nla_bitfield32 flags = { flag, flag };
+        nl_msg_put_unspec(request, TCA_ACT_FLAGS, &flags, sizeof flags);
+    }
+}

lib/tc.h

@@ -399,4 +399,6 @@ int tc_parse_action_stats(struct nlattr *action,
 int tc_dump_tc_action_start(char *name, struct nl_dump *dump);
 int parse_netlink_to_tc_policer(struct ofpbuf *reply, uint32_t police_idx[]);
 
+void nl_msg_put_act_tc_policy_flag(struct ofpbuf *request);
+
 #endif /* tc.h */