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Message-ID: <20130930021246.GC4768@verge.net.au>
Date: Mon, 30 Sep 2013 11:12:49 +0900
From: Simon Horman <horms@...ge.net.au>
To: Ben Pfaff <blp@...ira.com>
Cc: dev@...nvswitch.org, netdev@...r.kernel.org,
Jesse Gross <jesse@...ira.com>,
Pravin B Shelar <pshelar@...ira.com>,
Ravi K <rkerur@...il.com>,
Isaku Yamahata <yamahata@...inux.co.jp>,
Joe Stringer <joe@...d.net.nz>
Subject: Re: [PATCH v2.40 4/7] ofp-actions: Add separate OpenFlow 1.3 action
parser
On Fri, Sep 27, 2013 at 12:41:19PM -0700, Ben Pfaff wrote:
> On Fri, Sep 27, 2013 at 09:18:33AM +0900, Simon Horman wrote:
> > From: Joe Stringer <joe@...d.net.nz>
> >
> > This patch adds new ofpact_from_openflow13() and
> > ofpacts_from_openflow13() functions parallel to the existing ofpact
> > handling code. In the OpenFlow 1.3 version, push_mpls is handled
> > differently, but all other actions are handled by the existing code.
> >
> > For push_mpls, ofpact_push_mpls.ofpact.compat is set to
> > OFPUTIL_OFPAT13_PUSH_MPLS, which allows correct VLAN+MPLS datapath
> > behaviour to be determined at odp translation time.
> >
> > Signed-off-by: Joe Stringer <joe@...d.net.nz>
> > Signed-off-by: Simon Horman <horms@...ge.net.au>
>
> I am nervous about this idea of having ofpacts_pull_openflow11_actions()
> and ofpacts_pull_openflow11_instructions() try to figure out what
> version of OpenFlow is involved. It is a new and somewhat surprising
> requirements that the callers provide not just actions or instructions
> but a complete OpenFlow message. I see that the callers in ovs-ofctl.c
> don't satisfy this requirement.
Thanks, sorry for overlooking that.
I believe that Joe was worried about this at the time he implemented
this patch but for some reason I was not.
> I think that it would be better to make these functions' callers say
> what version of OpenFlow they are working with. One could provide a
> helper function like get_version_from_ofpbuf(), which should probably go
> in ofp-util.c, but I would want it to fail (assert-fail or segfault or
> whatever) if there is no L2 header pointer, instead of returning a
> default value (that, in this case anyway, we know must be wrong because
> OF1.0 never contains OF1.1+ actions or instructions).
I have written an incremental patch to implement your suggestion
and it seems that a helper function is not necessary.
For reference the incremental change that I currently have is as follows.
It is a bit noisy but seems clean to me.
diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
index 0c4a98b..e94f189 100644
--- a/lib/ofp-actions.c
+++ b/lib/ofp-actions.c
@@ -1119,22 +1119,14 @@ get_actions_from_instruction(const struct ofp11_instruction *inst,
*n_actions = (ntohs(inst->len) - sizeof *inst) / OFP11_INSTRUCTION_ALIGN;
}
-static uint8_t
-get_version_from_ofpbuf(const struct ofpbuf *openflow)
-{
- if (openflow && openflow->l2) {
- struct ofp_header *oh = openflow->l2;
- return oh->version;
- }
-
- return OFP10_VERSION;
-}
-
-/* Attempts to convert 'actions_len' bytes of OpenFlow 1.1 actions from the
+/* Attempts to convert 'actions_len' bytes of OpenFlow actions from the
* front of 'openflow' into ofpacts. On success, replaces any existing content
* in 'ofpacts' by the converted ofpacts; on failure, clears 'ofpacts'.
* Returns 0 if successful, otherwise an OpenFlow error.
*
+ * Actions are processed according to their OpenFlow version which
+ * is provided in the 'version' parameter.
+ *
* In most places in OpenFlow 1.1 and 1.2, actions appear encapsulated in
* instructions, so you should call ofpacts_pull_openflow11_instructions()
* instead of this function.
@@ -1146,22 +1138,27 @@ get_version_from_ofpbuf(const struct ofpbuf *openflow)
* valid in a specific context. */
enum ofperr
ofpacts_pull_openflow11_actions(struct ofpbuf *openflow,
+ enum ofp_version version,
unsigned int actions_len,
struct ofpbuf *ofpacts)
{
- uint8_t version = get_version_from_ofpbuf(openflow);
-
- if (version < OFP13_VERSION) {
+ switch (version) {
+ case OFP10_VERSION:
+ case OFP11_VERSION:
+ case OFP12_VERSION:
return ofpacts_pull_actions(openflow, actions_len, ofpacts,
ofpacts_from_openflow11);
- } else {
+ case OFP13_VERSION:
return ofpacts_pull_actions(openflow, actions_len, ofpacts,
ofpacts_from_openflow13);
+ default:
+ NOT_REACHED();
}
}
enum ofperr
ofpacts_pull_openflow11_instructions(struct ofpbuf *openflow,
+ enum ofp_version version,
unsigned int instructions_len,
struct ofpbuf *ofpacts)
{
@@ -1209,7 +1206,6 @@ ofpacts_pull_openflow11_instructions(struct ofpbuf *openflow,
if (insts[OVSINST_OFPIT11_APPLY_ACTIONS]) {
const union ofp_action *actions;
size_t n_actions;
- uint8_t version = get_version_from_ofpbuf(openflow);
get_actions_from_instruction(insts[OVSINST_OFPIT11_APPLY_ACTIONS],
&actions, &n_actions);
diff --git a/lib/ofp-actions.h b/lib/ofp-actions.h
index 2184489..d67fc3f 100644
--- a/lib/ofp-actions.h
+++ b/lib/ofp-actions.h
@@ -511,9 +511,11 @@ enum ofperr ofpacts_pull_openflow10(struct ofpbuf *openflow,
unsigned int actions_len,
struct ofpbuf *ofpacts);
enum ofperr ofpacts_pull_openflow11_actions(struct ofpbuf *openflow,
+ enum ofp_version version,
unsigned int actions_len,
struct ofpbuf *ofpacts);
enum ofperr ofpacts_pull_openflow11_instructions(struct ofpbuf *openflow,
+ enum ofp_version version,
unsigned int instructions_len,
struct ofpbuf *ofpacts);
enum ofperr ofpacts_check(const struct ofpact[], size_t ofpacts_len,
diff --git a/lib/ofp-print.c b/lib/ofp-print.c
index 6fe1cee..a0615b5 100644
--- a/lib/ofp-print.c
+++ b/lib/ofp-print.c
@@ -2224,7 +2224,7 @@ ofp_print_group_desc(struct ds *s, const struct ofp_header *oh)
struct ofputil_group_desc gd;
int retval;
- retval = ofputil_decode_group_desc_reply(&gd, &b);
+ retval = ofputil_decode_group_desc_reply(&gd, &b, oh->version);
if (retval) {
if (retval != EOF) {
ds_put_cstr(s, " ***parse error***");
diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index 173b534..570447a 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -1504,7 +1504,8 @@ ofputil_decode_flow_mod(struct ofputil_flow_mod *fm,
return error;
}
- error = ofpacts_pull_openflow11_instructions(&b, b.size, ofpacts);
+ error = ofpacts_pull_openflow11_instructions(&b, oh->version,
+ b.size, ofpacts);
if (error) {
return error;
}
@@ -2360,7 +2361,8 @@ ofputil_decode_flow_stats_reply(struct ofputil_flow_stats *fs,
return EINVAL;
}
- if (ofpacts_pull_openflow11_instructions(msg, length - sizeof *ofs -
+ if (ofpacts_pull_openflow11_instructions(msg, oh->version,
+ length - sizeof *ofs -
padded_match_len, ofpacts)) {
VLOG_WARN_RL(&bad_ofmsg_rl, "OFPST_FLOW reply bad instructions");
return EINVAL;
@@ -3092,7 +3094,8 @@ ofputil_decode_packet_out(struct ofputil_packet_out *po,
return error;
}
- error = ofpacts_pull_openflow11_actions(&b, ntohs(opo->actions_len),
+ error = ofpacts_pull_openflow11_actions(&b, oh->version,
+ ntohs(opo->actions_len),
ofpacts);
if (error) {
return error;
@@ -5674,8 +5677,8 @@ ofputil_append_group_desc_reply(const struct ofputil_group_desc *gds,
}
static enum ofperr
-ofputil_pull_buckets(struct ofpbuf *msg, size_t buckets_length,
- struct list *buckets)
+ofputil_pull_buckets(struct ofpbuf *msg, enum ofp_version version,
+ size_t buckets_length, struct list *buckets)
{
struct ofp11_bucket *ob;
@@ -5708,8 +5711,8 @@ ofputil_pull_buckets(struct ofpbuf *msg, size_t buckets_length,
buckets_length -= ob_len;
ofpbuf_init(&ofpacts, 0);
- error = ofpacts_pull_openflow11_actions(msg, ob_len - sizeof *ob,
- &ofpacts);
+ error = ofpacts_pull_openflow11_actions(msg, version,
+ ob_len - sizeof *ob, &ofpacts);
if (error) {
ofpbuf_uninit(&ofpacts);
ofputil_bucket_list_destroy(buckets);
@@ -5745,7 +5748,7 @@ ofputil_pull_buckets(struct ofpbuf *msg, size_t buckets_length,
* otherwise a positive errno value. */
int
ofputil_decode_group_desc_reply(struct ofputil_group_desc *gd,
- struct ofpbuf *msg)
+ struct ofpbuf *msg, enum ofp_version version)
{
struct ofp11_group_desc_stats *ogds;
size_t length;
@@ -5774,7 +5777,8 @@ ofputil_decode_group_desc_reply(struct ofputil_group_desc *gd,
return OFPERR_OFPBRC_BAD_LEN;
}
- return ofputil_pull_buckets(msg, length - sizeof *ogds, &gd->buckets);
+ return ofputil_pull_buckets(msg, version, length - sizeof *ogds,
+ &gd->buckets);
}
/* Converts abstract group mod 'gm' into a message for OpenFlow version
@@ -5857,7 +5861,7 @@ ofputil_decode_group_mod(const struct ofp_header *oh,
gm->type = ogm->type;
gm->group_id = ntohl(ogm->group_id);
- return ofputil_pull_buckets(&msg, msg.size, &gm->buckets);
+ return ofputil_pull_buckets(&msg, oh->version, msg.size, &gm->buckets);
}
/* Parse a queue status request message into 'oqsr'.
diff --git a/lib/ofp-util.h b/lib/ofp-util.h
index d5f34d7..5fa8fee 100644
--- a/lib/ofp-util.h
+++ b/lib/ofp-util.h
@@ -973,7 +973,7 @@ int ofputil_decode_group_stats_reply(struct ofpbuf *,
struct ofputil_group_stats *);
int ofputil_decode_group_desc_reply(struct ofputil_group_desc *,
- struct ofpbuf *);
+ struct ofpbuf *, enum ofp_version);
void ofputil_append_group_desc_reply(const struct ofputil_group_desc *,
struct list *buckets,
diff --git a/utilities/ovs-ofctl.c b/utilities/ovs-ofctl.c
index c2cc1f6..00d35aa 100644
--- a/utilities/ovs-ofctl.c
+++ b/utilities/ovs-ofctl.c
@@ -2968,8 +2968,8 @@ ofctl_parse_ofp11_actions(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
/* Convert to ofpacts. */
ofpbuf_init(&ofpacts, 0);
size = of11_in.size;
- error = ofpacts_pull_openflow11_actions(&of11_in, of11_in.size,
- &ofpacts);
+ error = ofpacts_pull_openflow11_actions(&of11_in, OFP11_VERSION,
+ of11_in.size, &ofpacts);
if (error) {
printf("bad OF1.1 actions: %s\n\n", ofperr_get_name(error));
ofpbuf_uninit(&ofpacts);
@@ -3036,8 +3036,8 @@ ofctl_parse_ofp11_instructions(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
/* Convert to ofpacts. */
ofpbuf_init(&ofpacts, 0);
size = of11_in.size;
- error = ofpacts_pull_openflow11_instructions(&of11_in, of11_in.size,
- &ofpacts);
+ error = ofpacts_pull_openflow11_instructions(&of11_in, OFP11_VERSION,
+ of11_in.size, &ofpacts);
if (!error) {
/* Verify actions. */
struct flow flow;
--
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