diff mbox

[ovs-dev,v1,1/2] nsh: enable struct ovs_action_encap_nsh to support variable length

Message ID 1502279114-60206-2-git-send-email-yi.y.yang@intel.com
State Changes Requested
Headers show

Commit Message

Yang, Yi Aug. 9, 2017, 11:45 a.m. UTC 
In order to adapt to MD type 1 and MD type 2 at the same
time and avoid breaking Linux kernel uAPI later, we change
struct ovs_action_encap_nsh to the below format.

struct ovs_action_encap_nsh {
    uint8_t flags;
    uint8_t mdtype;
    uint8_t mdlen;
    uint8_t np;
    __be32 path_hdr;
    uint8_t metadata[];
};

struct ovs_action_encap_nsh will be allocated dynamically when
it is used.

The following patch will change encap_nsh and decap_nsh into
push_nsh and pop_nsh, respectively, Linux kernel guys prefer
push_* and pop_*.

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
---
 datapath/linux/compat/include/linux/openvswitch.h |   4 +-
 lib/odp-util.c                                    | 101 +++++++++++++---------
 tests/nsh.at                                      |  10 +--
 3 files changed, 65 insertions(+), 50 deletions(-)

Comments

Ben Pfaff Aug. 9, 2017, 6:01 p.m. UTC | #1 
On Wed, Aug 09, 2017 at 07:45:13PM +0800, Yi Yang wrote:
> In order to adapt to MD type 1 and MD type 2 at the same
> time and avoid breaking Linux kernel uAPI later, we change
> struct ovs_action_encap_nsh to the below format.
> 
> struct ovs_action_encap_nsh {
>     uint8_t flags;
>     uint8_t mdtype;
>     uint8_t mdlen;
>     uint8_t np;
>     __be32 path_hdr;
>     uint8_t metadata[];
> };
> 
> struct ovs_action_encap_nsh will be allocated dynamically when
> it is used.
> 
> The following patch will change encap_nsh and decap_nsh into
> push_nsh and pop_nsh, respectively, Linux kernel guys prefer
> push_* and pop_*.
> 
> Signed-off-by: Yi Yang <yi.y.yang@intel.com>

This is an unusual format for a Netlink attribute.  More commonly, one
would put variable-length data into an attribute of its own, which
allows that data to be handled using the regular Netlink means.  Then
the mdlen and metadata members could be removed, since they would be
part of the additional attribute, and one might expect the mdtype member
to be removed as well since each type of metadata would be in a
different attribute type.
Yang, Yi Aug. 9, 2017, 7:52 p.m. UTC | #2 
Ben, no matter it is MD type 1 or MD type 2, we use the same netlink attribute OVS_ACTION_ATTR_ENCAP_NSH to transfer these data, another netlink attribute OVS_KEY_ATTR_NSH is for struct ovs_key_nsh. So I can't catch your point, can you explain it more?

-----Original Message-----
From: Ben Pfaff [mailto:blp@ovn.org] 
Sent: Thursday, August 10, 2017 2:01 AM
To: Yang, Yi Y <yi.y.yang@intel.com>
Cc: dev@openvswitch.org
Subject: Re: [PATCH v1 1/2] nsh: enable struct ovs_action_encap_nsh to support variable length

On Wed, Aug 09, 2017 at 07:45:13PM +0800, Yi Yang wrote:
> In order to adapt to MD type 1 and MD type 2 at the same time and 
> avoid breaking Linux kernel uAPI later, we change struct 
> ovs_action_encap_nsh to the below format.
> 
> struct ovs_action_encap_nsh {
>     uint8_t flags;
>     uint8_t mdtype;
>     uint8_t mdlen;
>     uint8_t np;
>     __be32 path_hdr;
>     uint8_t metadata[];
> };
> 
> struct ovs_action_encap_nsh will be allocated dynamically when it is 
> used.
> 
> The following patch will change encap_nsh and decap_nsh into push_nsh 
> and pop_nsh, respectively, Linux kernel guys prefer
> push_* and pop_*.
> 
> Signed-off-by: Yi Yang <yi.y.yang@intel.com>

This is an unusual format for a Netlink attribute.  More commonly, one would put variable-length data into an attribute of its own, which allows that data to be handled using the regular Netlink means.  Then the mdlen and metadata members could be removed, since they would be part of the additional attribute, and one might expect the mdtype member to be removed as well since each type of metadata would be in a different attribute type.
Ben Pfaff Aug. 9, 2017, 8:03 p.m. UTC | #3 
I gave a more detailed explanation later:
https://mail.openvswitch.org/pipermail/ovs-dev/2017-August/337164.html

On Wed, Aug 09, 2017 at 07:52:38PM +0000, Yang, Yi Y wrote:
> Ben, no matter it is MD type 1 or MD type 2, we use the same netlink attribute OVS_ACTION_ATTR_ENCAP_NSH to transfer these data, another netlink attribute OVS_KEY_ATTR_NSH is for struct ovs_key_nsh. So I can't catch your point, can you explain it more?
> 
> -----Original Message-----
> From: Ben Pfaff [mailto:blp@ovn.org] 
> Sent: Thursday, August 10, 2017 2:01 AM
> To: Yang, Yi Y <yi.y.yang@intel.com>
> Cc: dev@openvswitch.org
> Subject: Re: [PATCH v1 1/2] nsh: enable struct ovs_action_encap_nsh to support variable length
> 
> On Wed, Aug 09, 2017 at 07:45:13PM +0800, Yi Yang wrote:
> > In order to adapt to MD type 1 and MD type 2 at the same time and 
> > avoid breaking Linux kernel uAPI later, we change struct 
> > ovs_action_encap_nsh to the below format.
> > 
> > struct ovs_action_encap_nsh {
> >     uint8_t flags;
> >     uint8_t mdtype;
> >     uint8_t mdlen;
> >     uint8_t np;
> >     __be32 path_hdr;
> >     uint8_t metadata[];
> > };
> > 
> > struct ovs_action_encap_nsh will be allocated dynamically when it is 
> > used.
> > 
> > The following patch will change encap_nsh and decap_nsh into push_nsh 
> > and pop_nsh, respectively, Linux kernel guys prefer
> > push_* and pop_*.
> > 
> > Signed-off-by: Yi Yang <yi.y.yang@intel.com>
> 
> This is an unusual format for a Netlink attribute.  More commonly, one would put variable-length data into an attribute of its own, which allows that data to be handled using the regular Netlink means.  Then the mdlen and metadata members could be removed, since they would be part of the additional attribute, and one might expect the mdtype member to be removed as well since each type of metadata would be in a different attribute type.
Yang, Yi Aug. 9, 2017, 8:14 p.m. UTC | #4 
Noticed, please check the reply for that one.

-----Original Message-----
From: Ben Pfaff [mailto:blp@ovn.org] 
Sent: Thursday, August 10, 2017 4:04 AM
To: Yang, Yi Y <yi.y.yang@intel.com>
Cc: dev@openvswitch.org
Subject: Re: [PATCH v1 1/2] nsh: enable struct ovs_action_encap_nsh to support variable length

I gave a more detailed explanation later:
https://mail.openvswitch.org/pipermail/ovs-dev/2017-August/337164.html

On Wed, Aug 09, 2017 at 07:52:38PM +0000, Yang, Yi Y wrote:
> Ben, no matter it is MD type 1 or MD type 2, we use the same netlink attribute OVS_ACTION_ATTR_ENCAP_NSH to transfer these data, another netlink attribute OVS_KEY_ATTR_NSH is for struct ovs_key_nsh. So I can't catch your point, can you explain it more?
> 
> -----Original Message-----
> From: Ben Pfaff [mailto:blp@ovn.org]
> Sent: Thursday, August 10, 2017 2:01 AM
> To: Yang, Yi Y <yi.y.yang@intel.com>
> Cc: dev@openvswitch.org
> Subject: Re: [PATCH v1 1/2] nsh: enable struct ovs_action_encap_nsh to 
> support variable length
> 
> On Wed, Aug 09, 2017 at 07:45:13PM +0800, Yi Yang wrote:
> > In order to adapt to MD type 1 and MD type 2 at the same time and 
> > avoid breaking Linux kernel uAPI later, we change struct 
> > ovs_action_encap_nsh to the below format.
> > 
> > struct ovs_action_encap_nsh {
> >     uint8_t flags;
> >     uint8_t mdtype;
> >     uint8_t mdlen;
> >     uint8_t np;
> >     __be32 path_hdr;
> >     uint8_t metadata[];
> > };
> > 
> > struct ovs_action_encap_nsh will be allocated dynamically when it is 
> > used.
> > 
> > The following patch will change encap_nsh and decap_nsh into 
> > push_nsh and pop_nsh, respectively, Linux kernel guys prefer
> > push_* and pop_*.
> > 
> > Signed-off-by: Yi Yang <yi.y.yang@intel.com>
> 
> This is an unusual format for a Netlink attribute.  More commonly, one would put variable-length data into an attribute of its own, which allows that data to be handled using the regular Netlink means.  Then the mdlen and metadata members could be removed, since they would be part of the additional attribute, and one might expect the mdtype member to be removed as well since each type of metadata would be in a different attribute type.
diff mbox

Patch

diff --git a/datapath/linux/compat/include/linux/openvswitch.h b/datapath/linux/compat/include/linux/openvswitch.h
index bc6c94b..4936c12 100644
--- a/datapath/linux/compat/include/linux/openvswitch.h
+++ b/datapath/linux/compat/include/linux/openvswitch.h
@@ -793,7 +793,7 @@  struct ovs_action_push_eth {
 	struct ovs_key_ethernet addresses;
 };
 
-#define OVS_ENCAP_NSH_MAX_MD_LEN 16
+#define OVS_ENCAP_NSH_MAX_MD_LEN 248
 /*
  * struct ovs_action_encap_nsh - %OVS_ACTION_ATTR_ENCAP_NSH
  * @flags: NSH header flags.
@@ -809,7 +809,7 @@  struct ovs_action_encap_nsh {
     uint8_t mdlen;
     uint8_t np;
     __be32 path_hdr;
-    uint8_t metadata[OVS_ENCAP_NSH_MAX_MD_LEN];
+    uint8_t metadata[];
 };
 
 /**
diff --git a/lib/odp-util.c b/lib/odp-util.c
index ef8b39d..91452f5 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -1785,7 +1785,8 @@  parse_odp_encap_nsh_action(const char *s, struct ofpbuf *actions)
 {
     int n = 0;
     int ret = 0;
-    struct ovs_action_encap_nsh encap_nsh;
+    struct ovs_action_encap_nsh *encap_nsh =
+        xmalloc(sizeof *encap_nsh + OVS_ENCAP_NSH_MAX_MD_LEN);
     uint32_t spi;
     uint8_t si;
     uint32_t cd;
@@ -1796,11 +1797,11 @@  parse_odp_encap_nsh_action(const char *s, struct ofpbuf *actions)
     }
 
     /* The default is NSH_M_TYPE1 */
-    encap_nsh.flags = 0;
-    encap_nsh.mdtype = NSH_M_TYPE1;
-    encap_nsh.mdlen = NSH_M_TYPE1_MDLEN;
-    encap_nsh.path_hdr = htonl(255);
-    memset(encap_nsh.metadata, 0, NSH_M_TYPE1_MDLEN);
+    encap_nsh->flags = 0;
+    encap_nsh->mdtype = NSH_M_TYPE1;
+    encap_nsh->mdlen = NSH_M_TYPE1_MDLEN;
+    encap_nsh->path_hdr = htonl(255);
+    memset(encap_nsh->metadata, 0, encap_nsh->mdlen);
 
     for (;;) {
         n += strspn(s + n, delimiters);
@@ -1808,17 +1809,17 @@  parse_odp_encap_nsh_action(const char *s, struct ofpbuf *actions)
             break;
         }
 
-        if (ovs_scan_len(s, &n, "flags=%"SCNi8, &encap_nsh.flags)) {
+        if (ovs_scan_len(s, &n, "flags=%"SCNi8, &encap_nsh->flags)) {
             continue;
         }
-        if (ovs_scan_len(s, &n, "mdtype=%"SCNi8, &encap_nsh.mdtype)) {
-            switch (encap_nsh.mdtype) {
+        if (ovs_scan_len(s, &n, "mdtype=%"SCNi8, &encap_nsh->mdtype)) {
+            switch (encap_nsh->mdtype) {
             case NSH_M_TYPE1:
                 /* This is the default format. */;
                 break;
             case NSH_M_TYPE2:
                 /* Length will be updated later. */
-                encap_nsh.mdlen = 0;
+                encap_nsh->mdlen = 0;
                 break;
             default:
                 ret = -EINVAL;
@@ -1826,24 +1827,24 @@  parse_odp_encap_nsh_action(const char *s, struct ofpbuf *actions)
             }
             continue;
         }
-        if (ovs_scan_len(s, &n, "np=%"SCNi8, &encap_nsh.np)) {
+        if (ovs_scan_len(s, &n, "np=%"SCNi8, &encap_nsh->np)) {
             continue;
         }
         if (ovs_scan_len(s, &n, "spi=0x%"SCNx32, &spi)) {
-            encap_nsh.path_hdr =
+            encap_nsh->path_hdr =
                     htonl(((spi << NSH_SPI_SHIFT) & NSH_SPI_MASK) |
-                            (ntohl(encap_nsh.path_hdr) & ~NSH_SPI_MASK));
+                            (ntohl(encap_nsh->path_hdr) & ~NSH_SPI_MASK));
             continue;
         }
         if (ovs_scan_len(s, &n, "si=%"SCNi8, &si)) {
-            encap_nsh.path_hdr =
+            encap_nsh->path_hdr =
                     htonl((si << NSH_SI_SHIFT) |
-                            (ntohl(encap_nsh.path_hdr) & ~NSH_SI_MASK));
+                            (ntohl(encap_nsh->path_hdr) & ~NSH_SI_MASK));
             continue;
         }
-        if (encap_nsh.mdtype == NSH_M_TYPE1) {
+        if (encap_nsh->mdtype == NSH_M_TYPE1) {
             struct nsh_md1_ctx *md1 =
-                ALIGNED_CAST(struct nsh_md1_ctx *, encap_nsh.metadata);
+                ALIGNED_CAST(struct nsh_md1_ctx *, encap_nsh->metadata);
             if (ovs_scan_len(s, &n, "c1=0x%"SCNx32, &cd)) {
                 put_16aligned_be32(&md1->c[0], htonl(cd));
                 continue;
@@ -1861,30 +1862,34 @@  parse_odp_encap_nsh_action(const char *s, struct ofpbuf *actions)
                 continue;
             }
         }
-        else if (encap_nsh.mdtype == NSH_M_TYPE2) {
+        else if (encap_nsh->mdtype == NSH_M_TYPE2) {
             struct ofpbuf b;
             char buf[512];
             size_t mdlen;
             if (ovs_scan_len(s, &n, "md2=0x%511[0-9a-fA-F]", buf)) {
-                ofpbuf_use_stub(&b, encap_nsh.metadata,
+                ofpbuf_use_stub(&b, encap_nsh->metadata,
                                 OVS_ENCAP_NSH_MAX_MD_LEN);
                 ofpbuf_put_hex(&b, buf, &mdlen);
-                encap_nsh.mdlen = mdlen;
+                encap_nsh->mdlen = mdlen;
                 ofpbuf_uninit(&b);
             }
             continue;
         }
     }
 out:
-    if (ret < 0) {
-        return ret;
-    } else {
-        size_t size = offsetof(struct ovs_action_encap_nsh, metadata)
-                + ROUND_UP(encap_nsh.mdlen, 4);
-        nl_msg_put_unspec(actions, OVS_ACTION_ATTR_ENCAP_NSH,
-                          &encap_nsh, size);
-        return n;
+    if (ret >= 0) {
+        size_t size = sizeof(struct ovs_action_encap_nsh)
+                      + ROUND_UP(encap_nsh->mdlen, 4);
+        size_t pad_len = size - sizeof(struct ovs_action_encap_nsh)
+                         - encap_nsh->mdlen;
+        if (encap_nsh->mdlen > NSH_M_TYPE1_MDLEN && pad_len > 0) {
+            memset(encap_nsh->metadata + encap_nsh->mdlen, 0, pad_len);
+        }
+        nl_msg_put_unspec(actions, OVS_ACTION_ATTR_ENCAP_NSH, encap_nsh, size);
+        ret = n;
     }
+    free(encap_nsh);
+    return ret;
 }
 
 static int
@@ -6798,19 +6803,22 @@  odp_put_encap_nsh_action(struct ofpbuf *odp_actions,
                          const struct flow *flow,
                          struct ofpbuf *encap_data)
 {
-    struct ovs_action_encap_nsh encap_nsh;
-
-    encap_nsh.flags = flow->nsh.flags;
-    encap_nsh.mdtype = flow->nsh.mdtype;
-    encap_nsh.np = flow->nsh.np;
-    encap_nsh.path_hdr = htonl((ntohl(flow->nsh.spi) << NSH_SPI_SHIFT) |
+    size_t size;
+    size_t pad_len;
+    struct ovs_action_encap_nsh *encap_nsh =
+        xmalloc(sizeof *encap_nsh + OVS_ENCAP_NSH_MAX_MD_LEN);
+
+    encap_nsh->flags = flow->nsh.flags;
+    encap_nsh->mdtype = flow->nsh.mdtype;
+    encap_nsh->np = flow->nsh.np;
+    encap_nsh->path_hdr = htonl((ntohl(flow->nsh.spi) << NSH_SPI_SHIFT) |
                                    flow->nsh.si);
 
-    switch (encap_nsh.mdtype) {
+    switch (encap_nsh->mdtype) {
     case NSH_M_TYPE1: {
         struct nsh_md1_ctx *md1 =
-            ALIGNED_CAST(struct nsh_md1_ctx *, encap_nsh.metadata);
-        encap_nsh.mdlen = NSH_M_TYPE1_MDLEN;
+            ALIGNED_CAST(struct nsh_md1_ctx *, encap_nsh->metadata);
+        encap_nsh->mdlen = NSH_M_TYPE1_MDLEN;
         for (int i = 0; i < 4; i++) {
             put_16aligned_be32(&md1->c[i], flow->nsh.c[i]);
         }
@@ -6819,18 +6827,25 @@  odp_put_encap_nsh_action(struct ofpbuf *odp_actions,
     case NSH_M_TYPE2:
         if (encap_data) {
             ovs_assert(encap_data->size < OVS_ENCAP_NSH_MAX_MD_LEN);
-            encap_nsh.mdlen = encap_data->size;
-            memcpy(encap_nsh.metadata, encap_data->data, encap_data->size);
+            encap_nsh->mdlen = encap_data->size;
+            memcpy(encap_nsh->metadata, encap_data->data, encap_data->size);
         } else {
-            encap_nsh.mdlen = 0;
+            encap_nsh->mdlen = 0;
         }
         break;
     default:
-        encap_nsh.mdlen = 0;
+        encap_nsh->mdlen = 0;
         break;
     }
-    nl_msg_put_unspec(odp_actions, OVS_ACTION_ATTR_ENCAP_NSH,
-                      &encap_nsh, sizeof(encap_nsh));
+    size = sizeof(struct ovs_action_encap_nsh)
+           + ROUND_UP(encap_nsh->mdlen, 4);
+    pad_len = size - sizeof(struct ovs_action_encap_nsh)
+              - encap_nsh->mdlen;
+    if (pad_len > 0) {
+        memset(encap_nsh->metadata + encap_nsh->mdlen, 0, pad_len);
+    }
+    nl_msg_put_unspec(odp_actions, OVS_ACTION_ATTR_ENCAP_NSH, encap_nsh, size);
+    free(encap_nsh);
 }
 
 static void
diff --git a/tests/nsh.at b/tests/nsh.at
index aa80a2a..cf567e7 100644
--- a/tests/nsh.at
+++ b/tests/nsh.at
@@ -195,7 +195,7 @@  ovs-vsctl set bridge br0 datapath_type=dummy \
         add-port br0 v4 -- set Interface v4 type=patch options:peer=v3 ofport_request=4])
 
 AT_DATA([flows.txt], [dnl
-    table=0,in_port=1,ip,actions=encap(nsh(md_type=2,tlv(0x1000,10,0x12345678))),set_field:0x1234->nsh_spi,encap(ethernet),set_field:11:22:33:44:55:66->dl_dst,3
+    table=0,in_port=1,ip,actions=encap(nsh(md_type=2,tlv(0x1000,10,0x12345678),tlv(0x2000,20,0xfedcba9876543210))),set_field:0x1234->nsh_spi,encap(ethernet),set_field:11:22:33:44:55:66->dl_dst,3
     table=0,in_port=4,dl_type=0x894f,nsh_mdtype=2,nsh_spi=0x1234,actions=decap(),decap(),2
 ])
 
@@ -205,7 +205,7 @@  AT_CHECK([
     ovs-ofctl -Oopenflow13 dump-flows br0 | ofctl_strip | sort | grep actions
 ], [0], [dnl
  in_port=4,dl_type=0x894f,nsh_mdtype=2,nsh_spi=0x1234 actions=decap(),decap(),output:2
- ip,in_port=1 actions=encap(nsh(md_type=2,tlv(0x1000,10,0x12345678))),set_field:0x1234->nsh_spi,encap(ethernet),set_field:11:22:33:44:55:66->eth_dst,output:3
+ ip,in_port=1 actions=encap(nsh(md_type=2,tlv(0x1000,10,0x12345678),tlv(0x2000,20,0xfedcba9876543210))),set_field:0x1234->nsh_spi,encap(ethernet),set_field:11:22:33:44:55:66->eth_dst,output:3
 ])
 
 AT_CHECK([
@@ -216,7 +216,7 @@  Flow: icmp,in_port=1,vlan_tci=0x0000,dl_src=00:11:22:33:44:55,dl_dst=66:77:88:99
 bridge("br0")
 -------------
  0. ip,in_port=1, priority 32768
-    encap(nsh(md_type=2,tlv(0x1000,10,0x12345678)))
+    encap(nsh(md_type=2,tlv(0x1000,10,0x12345678),tlv(0x2000,20,0xfedcba9876543210)))
     set_field:0x1234->nsh_spi
     encap(ethernet)
     set_field:11:22:33:44:55:66->eth_dst
@@ -230,7 +230,7 @@  bridge("br0")
 
 Final flow: in_port=1,vlan_tci=0x0000,dl_src=00:00:00:00:00:00,dl_dst=11:22:33:44:55:66,dl_type=0x894f,nsh_flags=0,nsh_mdtype=2,nsh_np=3,nsh_spi=0x1234,nsh_si=255,nw_proto=0,nw_tos=0,nw_ecn=0,nw_ttl=0
 Megaflow: recirc_id=0,eth,ip,in_port=1,dl_dst=66:77:88:99:aa:bb,nw_frag=no
-Datapath actions: encap_nsh(flags=0,mdtype=2,np=3,spi=0x1234,si=255,md2=0x10000a0412345678),push_eth(src=00:00:00:00:00:00,dst=11:22:33:44:55:66),pop_eth,decap_nsh(),set(eth(dst=11:22:33:44:55:66)),recirc(0x1)
+Datapath actions: encap_nsh(flags=0,mdtype=2,np=3,spi=0x1234,si=255,md2=0x10000a041234567820001408fedcba9876543210),push_eth(src=00:00:00:00:00:00,dst=11:22:33:44:55:66),pop_eth,decap_nsh(),set(eth(dst=11:22:33:44:55:66)),recirc(0x1)
 ])
 
 AT_CHECK([
@@ -264,7 +264,7 @@  ovs-appctl time/warp 1000
 AT_CHECK([
     ovs-appctl dpctl/dump-flows dummy@ovs-dummy | strip_used | grep -v ipv6 | sort
 ], [0], [flow-dump from non-dpdk interfaces:
-recirc_id(0),in_port(1),packet_type(ns=0,id=0),eth(dst=1e:2c:e9:2a:66:9e),eth_type(0x0800),ipv4(frag=no), packets:1, bytes:98, used:0.0s, actions:encap_nsh(flags=0,mdtype=2,np=3,spi=0x1234,si=255,md2=0x10000a0412345678),push_eth(src=00:00:00:00:00:00,dst=11:22:33:44:55:66),pop_eth,decap_nsh(),set(eth(dst=11:22:33:44:55:66)),recirc(0x3)
+recirc_id(0),in_port(1),packet_type(ns=0,id=0),eth(dst=1e:2c:e9:2a:66:9e),eth_type(0x0800),ipv4(frag=no), packets:1, bytes:98, used:0.0s, actions:encap_nsh(flags=0,mdtype=2,np=3,spi=0x1234,si=255,md2=0x10000a041234567820001408fedcba9876543210),push_eth(src=00:00:00:00:00:00,dst=11:22:33:44:55:66),pop_eth,decap_nsh(),set(eth(dst=11:22:33:44:55:66)),recirc(0x3)
 recirc_id(0x3),in_port(1),packet_type(ns=0,id=0),eth_type(0x0800),ipv4(frag=no), packets:1, bytes:98, used:0.0s, actions:2
 ])