[ovs-discuss] [PATCH] lib/ofp-util.c, lib/vconn.c, lib/rconn.c, lib/ofp-errors.c:: OFPERR_OFPBRC_BAD_VERSION generated from switch when there is version mismatch.
Amit Tewari
Amit.Tewari at nechclst.in
Wed Jul 4 07:05:39 UTC 2012
Hi Ben,
I am sending patch for generating OFPERR_OFPBRC_BAD_VERSION error in case of version mismatch in
openflow packets from controller to switch. This patch is for latest release 1.6.1.
I have also patched lib/ofp-errors.c file so that OFPERR_OFPBRC_BAD_VERSION error packet contains switch
supported version i.e OFP10_VERSION.
Design description and rationale -
---------------------------------------
We are returning OFPERR_OFPBRC_BAD_VERSION error in vconn.c file in do_recv routine
for version mismatch for all openflow packets from controller and we prevent reset of
connection in rconn.c file in rconn_recv routine by checking for OFPERR_OFPBRC_BAD_VERSION
error from do_recv routine.
Then we are checking the version mismatch between openflow packets in ofp util.c ofputil_lookup_openflow_message routine,
this routine was returning earlier BAD_SUBTYPE error so we put a check for version mistmatch in this routine and
return BAD_VERSION error and if version matches and if header type doesn't matches then still it returns BAD_SUBTYPE error.
When we return BAD_VERSION error the error packet was having version of controller request packet and
not switch supported version, so we put a check in ofp-errors.c file for setting version in error packet to switch
supported version i.e OFP10_VERSION for BAD_VERSION error.
Testing after merging patch in OVS 1.6.1
-------------------------------------------------
1. Verify OFPET_BAD_REQUEST OFPBRC_BAD_VERSION code message from
switch to controller for all openflow packets mentioned in file ofproto.c
in handle_openflow__ routine when there is "version mismatch".
2. Verify request and reply message from controller to switch for all openflow packets
mentioned in file ofproto.c in handle_openflow__ routine when there is "version matches".
Patch
---------
lib/ofp-util.c | 3 +++
lib/vconn.c | 2 ++
lib/rconn.c | 3 ++-
lib/ofp-errorc.c | 3 +++
4 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index 15340f6..7591f0f 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -355,6 +355,9 @@ ofputil_lookup_openflow_message(const struct ofputil_msg_category *cat,
}
}
+ if (version != type->ofp_version) {
+ return OFPERR_OFPBRC_BAD_VERSION;
+ }
VLOG_WARN_RL(&bad_ofmsg_rl, "received %s of unknown type %"PRIu32,
cat->name, value);
return cat->missing_error;
diff --git a/lib/vconn.c b/lib/vconn.c
index 5da5026..47622c6 100644
--- a/lib/vconn.c
+++ b/lib/vconn.c
@@ -555,6 +555,8 @@ do_recv(struct vconn *vconn, struct ofpbuf **msgp)
"%s: received OpenFlow version 0x%02"PRIx8" "
"!= expected %02x",
vconn->name, oh->version, vconn->version);
+ retval = OFPERR_OFPBRC_BAD_VERSION;
+ return retval;
}
ofpbuf_delete(*msgp);
retval = EPROTO;
diff --git a/lib/rconn.c b/lib/rconn.c
index 1b69b8f..097d5ae 100644
--- a/lib/rconn.c
+++ b/lib/rconn.c
@@ -24,6 +24,7 @@
#include "coverage.h"
#include "ofp-util.h"
#include "ofpbuf.h"
+#include "ofp-errors.h"
#include "openflow/openflow.h"
#include "poll-loop.h"
#include "sat-math.h"
@@ -521,7 +522,7 @@ rconn_recv(struct rconn *rc)
if (rc->state & (S_ACTIVE | S_IDLE)) {
struct ofpbuf *buffer;
int error = vconn_recv(rc->vconn, &buffer);
- if (!error) {
+ if (!error || error == OFPERR_OFPBRC_BAD_VERSION) {
copy_to_monitor(rc, buffer);
if (rc->probably_admitted || is_admitted_msg(buffer)
|| time_now() - rc->last_connected >= 30) {
diff --git a/lib/ofp-errors.c b/lib/ofp-errors.c
index 028475e..2af01ff 100644
--- a/lib/ofp-errors.c
+++ b/lib/ofp-errors.c
@@ -187,6 +187,9 @@ ofperr_encode_reply(enum ofperr error, const struct ofp_header *oh)
uint16_t len = ntohs(oh->length);
domain = ofperr_domain_from_version(oh->version);
+ if (error == OFPERR_OFPBRC_BAD_VERSION) {
+ domain = ofperr_domain_from_version(OFP10_VERSION);
+ }
return ofperr_encode_msg__(error, domain, oh->xid, oh, MIN(len, 64));
}
Regards
Amit Tewari
NEC HCL ST
-----Original Message-----
From: discuss-bounces at openvswitch.org [mailto:discuss-bounces at openvswitch.org] On Behalf Of Ben Pfaff
Sent: Thursday, June 28, 2012 8:54 PM
To: Amit Tewari
Cc: 'bugs at openvswitch.org'; 'discuss at openvswitch.org'
Subject: Re: [ovs-discuss] [PATCH] ofproto/ofproto.c, lib/vconn.c:: OFPBRC_BAD_VERSION generated from switch when there is version mismatch.
On Thu, Jun 28, 2012 at 06:16:06AM +0000, Amit Tewari wrote:
> As per our analysis and requirement we provided the patch for selected openflow messages which carry useful data in data field for controller from switch.
>
> Please confirm whether you have applied the patch we provided earlier?
No. It doesn't make sense to add a special case for every message in
the middle of the code. If we need to handle this at all, we should
handle it in a single place without duplicate special cases.
Also, your patch was against an old version of Open vSwitch. We only
accept patches against the newest version.
> Please let me know if am missing any openflow message.
See, that's the problem. You *can* miss some messages if you do it your
way.
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