diff mbox series

[ovs-dev,v2,3/4] netdev-offload-tc: Add don't fragment support to encap action.

Message ID 7b6d177d692fd08b64a5b15828238ec1dd6440f2.1728907640.git.echaudro@redhat.com
State New
Delegated to: Simon Horman
Headers show
Series Add missing TC flower tunnel match and encap flags. | expand

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Commit Message

Eelco Chaudron Oct. 14, 2024, 12:09 p.m. UTC 
This patch adds "Don't Fragment" (DF) flag support to the encap action,
if supported by the kernel. If the kernel does not support this,
it falls back to the previous behavior of ignoring the DF request.

Acked-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
---
 acinclude.m4                         |  6 +++---
 include/linux/tc_act/tc_tunnel_key.h |  3 ++-
 lib/netdev-offload-tc.c              | 16 +++++++++++-----
 lib/tc.c                             |  6 ++++++
 lib/tc.h                             |  1 +
 5 files changed, 23 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/acinclude.m4 b/acinclude.m4
index f4cb4a146..8658bcfcb 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -193,10 +193,10 @@  AC_DEFUN([OVS_CHECK_LINUX_TC], [
 
   AC_COMPILE_IFELSE([
     AC_LANG_PROGRAM([#include <linux/tc_act/tc_tunnel_key.h>], [
-        int x = TCA_TUNNEL_KEY_ENC_OPTS_VXLAN;
+        int x = TCA_TUNNEL_KEY_NO_FRAG;
     ])],
-    [AC_DEFINE([HAVE_TCA_TUNNEL_KEY_ENC_OPTS_VXLAN], [1],
-               [Define to 1 if TCA_TUNNEL_KEY_ENC_OPTS_VXLAN is available.])])
+    [AC_DEFINE([HAVE_TCA_TUNNEL_KEY_NO_FRAG], [1],
+               [Define to 1 if TCA_TUNNEL_KEY_NO_FRAG is available.])])
 
   AC_COMPILE_IFELSE([
     AC_LANG_PROGRAM([#include <linux/tc_act/tc_pedit.h>], [
diff --git a/include/linux/tc_act/tc_tunnel_key.h b/include/linux/tc_act/tc_tunnel_key.h
index 17291b90b..edb64262e 100644
--- a/include/linux/tc_act/tc_tunnel_key.h
+++ b/include/linux/tc_act/tc_tunnel_key.h
@@ -1,7 +1,7 @@ 
 #ifndef __LINUX_TC_ACT_TC_TUNNEL_KEY_WRAPPER_H
 #define __LINUX_TC_ACT_TC_TUNNEL_KEY_WRAPPER_H 1
 
-#if defined(__KERNEL__) || defined(HAVE_TCA_TUNNEL_KEY_ENC_OPTS_VXLAN)
+#if defined(__KERNEL__) || defined(HAVE_TCA_TUNNEL_KEY_NO_FRAG)
 #include_next <linux/tc_act/tc_tunnel_key.h>
 #else
 
@@ -42,6 +42,7 @@  enum {
                                      */
 	TCA_TUNNEL_KEY_ENC_TOS,		    /* u8 */
 	TCA_TUNNEL_KEY_ENC_TTL,		    /* u8 */
+	TCA_TUNNEL_KEY_NO_FRAG,		    /* flag */
 	__TCA_TUNNEL_KEY_MAX,
 };
 
diff --git a/lib/netdev-offload-tc.c b/lib/netdev-offload-tc.c
index c6aa51c68..dd2afc64f 100644
--- a/lib/netdev-offload-tc.c
+++ b/lib/netdev-offload-tc.c
@@ -919,6 +919,9 @@  parse_tc_flower_to_actions__(struct tc_flower *flower, struct ofpbuf *buf,
             if (!action->encap.no_csum) {
                 nl_msg_put_flag(buf, OVS_TUNNEL_KEY_ATTR_CSUM);
             }
+            if (action->encap.dont_fragment) {
+                nl_msg_put_flag(buf, OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT);
+            }
             ret = parse_tc_flower_vxlan_tun_opts(action, buf);
             if (ret) {
                 return ret;
@@ -1641,11 +1644,14 @@  parse_put_flow_set_action(struct tc_flower *flower, struct tc_action *action,
         }
         break;
         case OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT: {
-            /* XXX: This is wrong!  We're ignoring the DF flag configuration
-             * requested by the user.  However, TC for now has no way to pass
-             * that flag and it is set by default, meaning tunnel offloading
-             * will not work if 'options:df_default=false' is not set.
-             * Keeping incorrect behavior for now. */
+            if (enc_flags_support) {
+                action->encap.dont_fragment = true;
+            } else {
+                /* For kernels not supporting the DF flag, we ignoring the
+                 * configuration requested by the user. This to keep the old,
+                 * incorrect behaviour, and allow tunnels to be offloaded by
+                 * TC with these kernels.  */
+            }
         }
         break;
         case OVS_TUNNEL_KEY_ATTR_CSUM: {
diff --git a/lib/tc.c b/lib/tc.c
index 6c853b8e6..175e770d4 100644
--- a/lib/tc.c
+++ b/lib/tc.c
@@ -1229,6 +1229,7 @@  static const struct nl_policy tunnel_key_policy[] = {
     [TCA_TUNNEL_KEY_ENC_TTL] = { .type = NL_A_U8, .optional = true, },
     [TCA_TUNNEL_KEY_ENC_OPTS] = { .type = NL_A_NESTED, .optional = true, },
     [TCA_TUNNEL_KEY_NO_CSUM] = { .type = NL_A_U8, .optional = true, },
+    [TCA_TUNNEL_KEY_NO_FRAG] = { .type = NL_A_FLAG, .optional = true, },
 };
 
 static int
@@ -1394,6 +1395,7 @@  nl_parse_act_tunnel_key(struct nlattr *options, struct tc_flower *flower)
         struct nlattr *ttl = tun_attrs[TCA_TUNNEL_KEY_ENC_TTL];
         struct nlattr *tun_opt = tun_attrs[TCA_TUNNEL_KEY_ENC_OPTS];
         struct nlattr *no_csum = tun_attrs[TCA_TUNNEL_KEY_NO_CSUM];
+        struct nlattr *no_frag = tun_attrs[TCA_TUNNEL_KEY_NO_FRAG];
 
         action = &flower->actions[flower->action_count++];
         action->type = TC_ACT_ENCAP;
@@ -1411,6 +1413,7 @@  nl_parse_act_tunnel_key(struct nlattr *options, struct tc_flower *flower)
         action->encap.tos = tos ? nl_attr_get_u8(tos) : 0;
         action->encap.ttl = ttl ? nl_attr_get_u8(ttl) : 0;
         action->encap.no_csum = no_csum ? nl_attr_get_u8(no_csum) : 0;
+        action->encap.dont_fragment = no_frag ? true : false;
 
         err = nl_parse_act_tunnel_opts(tun_opt, action);
         if (err) {
@@ -2747,6 +2750,9 @@  nl_msg_put_act_tunnel_key_set(struct ofpbuf *request,
             nl_msg_put_be16(request, TCA_TUNNEL_KEY_ENC_DST_PORT,
                             encap->tp_dst);
         }
+        if (encap->dont_fragment) {
+            nl_msg_put_flag(request, TCA_TUNNEL_KEY_NO_FRAG);
+        }
         nl_msg_put_act_tunnel_vxlan_opts(request, encap);
         nl_msg_put_act_tunnel_geneve_option(request, &encap->data);
         nl_msg_put_u8(request, TCA_TUNNEL_KEY_NO_CSUM, encap->no_csum);
diff --git a/lib/tc.h b/lib/tc.h
index c0a1d5d0e..8b9a1655a 100644
--- a/lib/tc.h
+++ b/lib/tc.h
@@ -229,6 +229,7 @@  struct tc_action_encap {
     uint8_t tos;
     uint8_t ttl;
     uint8_t no_csum;
+    bool dont_fragment;
     struct {
         ovs_be32 ipv4_src;
         ovs_be32 ipv4_dst;