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Message-Id: <1385005606-30130-2-git-send-email-horms@verge.net.au>
Date: Thu, 21 Nov 2013 12:46:42 +0900
From: Simon Horman <horms@...ge.net.au>
To: dev@...nvswitch.org, netdev@...r.kernel.org,
Jesse Gross <jesse@...ira.com>, Ben Pfaff <blp@...ira.com>
Cc: Pravin B Shelar <pshelar@...ira.com>, Ravi K <rkerur@...il.com>,
Joe Stringer <joe@...d.net.nz>
Subject: [PATCH v2.51 1/5] ofp-actions: Allow Consistency checking of OF1.3+ VLAN actions after mpls_push
The aim of this patch is to support provide infrastructure for verification
of VLAN actions after an mpls_push action for OpenFlow1.3. This supplements
existing support for verifying these actions for pre-OpenFlow1.3.
In OpenFlow1.1 and 1.2 MPLS tags are pushed after any VLAN tags that
immediately follow the ethernet header. This is pre-OpenFlow1.3 tag
ordering. Open vSwitch also uses this ordering when supporting MPLS
actions via Nicira extensions to OpenFlow1.0.
When using pre-OpenFlow1.3 tag ordering an MPLS push action does not
affect the VLANs of a packet. If VLAN tags are present immediately after
the ethernet header then they remain present there.
In of OpenFlow1.3+ MPLS LSEs are pushed before any VLAN tags that
immediately follow the ethernet header. This is OpenFlow1.3+ tag
ordering.
When using OpenFlow1.3+ tag ordering an MPLS push action affects the
VLANs of a packet as any VLAN tags previously present after the ethernet
header are moved to be immediately after the newly pushed MPLS LSE. Thus
for the purpose of action consistency checking a packet may be changed
from a VLAN packet to a non-VLAN packet.
In this way the effective value of the VLAN TCI of a packet may differ
after an MPLS push depending on the OpenFlow version in use.
This patch does not enable the logic described above.
Rather it is disabled in ofpacts_check__(). It should
be enabled when support for OpenFlow1.3+ tag order is added
and enabled.
Signed-off-by: Simon Horman <horms@...ge.net.au>
---
v2.51
* First non-RFC post
---
lib/ofp-actions.c | 202 +++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 169 insertions(+), 33 deletions(-)
diff --git a/lib/ofp-actions.c b/lib/ofp-actions.c
index e07ea1d..6754939 100644
--- a/lib/ofp-actions.c
+++ b/lib/ofp-actions.c
@@ -1879,15 +1879,108 @@ inconsistent_match(enum ofputil_protocol *usable_protocols)
*usable_protocols &= OFPUTIL_P_OF10_ANY;
}
+/* Checks the consistency of a VLAN action by checking the state of the
+ * VLAN_CFI bit of the VLAN TCI against 'desired_cfi' and updating
+ * '*usable_protocols' accordingly.
+ *
+ * 'pre_of13_vlan_tci' is the VLAN TCI to check against for pre-OpenFlow1.3
+ * protocols. 'of13_vlan_tci' is the VLAN TCI to check against for
+ * OpenFlow1.3+ protocols.
+ *
+ * If the desired_cfi bit is in the desired state for any usable protocol
+ * then true is returned. Else false is returned.
+ *
+ * The check for consistent VLAN actions may depend on the OpenFlow version
+ * used and whether the VLAN action is preceded by an MPLS push action or
+ * not.
+ *
+ * In OpenFlow1.1 and 1.2 MPLS tags are pushed after any VLAN tags that
+ * immediately follow the ethernet header. This is pre-OpenFlow1.3 tag
+ * ordering. Open vSwitch also uses this ordering when supporting MPLS
+ * actions via Nicira extensions to OpenFlow1.0.
+ *
+ * When using pre-OpenFlow1.3 tag ordering an MPLS push action does not
+ * affect the VLANs of a packet. If VLAN tags are present immediately after
+ * the ethernet header then they remain present there.
+ *
+ * In of OpenFlow1.3+ MPLS LSEs are pushed before any VLAN tags that
+ * immediately follow the ethernet header. This is OpenFlow1.3+ tag
+ * ordering.
+ *
+ * When using OpenFlow1.3+ tag ordering an MPLS push action affects the
+ * VLANs of a packet as any VLAN tags previously present after the ethernet
+ * header are moved to be immediately after the newly pushed MPLS LSE. Thus
+ * for the purpose of action consistency checking a packet may be changed
+ * from a VLAN packet to a non-VLAN packet.
+ *
+ * In this way the effective value of the VLAN TCI of a packet may differ
+ * after an MPLS push depending on the OpenFlow version in use. This
+ * corresponds to the 'pre_of13_vlan_tci' and 'of13_vlan_tci' parameters of
+ * this function. */
+static bool
+ofpact_check_vlan(enum ofputil_protocol *usable_protocols,
+ ovs_be16 pre_of13_vlan_tci, ovs_be16 of13_vlan_tci,
+ bool desired_cfi)
+{
+ bool ok = false;
+ ovs_be16 tci, mask;
+
+ mask = htons(VLAN_CFI);
+ if (desired_cfi) {
+ tci = mask;
+ } else {
+ tci = htons(0);
+ }
+
+ if (*usable_protocols & OFPUTIL_P_OF13_UP) {
+ if ((of13_vlan_tci & mask) != tci) {
+ /* CFI miss-match for OpenFlow1.3+: clear those protocols */
+ *usable_protocols &= ~OFPUTIL_P_OF13_UP;
+ } else {
+ /* CFI bit is valid for a usable protocol:
+ * eventually return true */
+ ok = true;
+ }
+ }
+
+ if (*usable_protocols & ~OFPUTIL_P_OF13_UP) {
+ if ((pre_of13_vlan_tci & mask) != tci) {
+ enum ofputil_protocol of13_up;
+
+ /* CFI miss-match for pre-OpenFlow1.3: clear those protocols
+ * except OFPUTIL_P_OF10_ANY as it allows inconsistency. */
+ of13_up = *usable_protocols & OFPUTIL_P_OF13_UP;
+ inconsistent_match(usable_protocols);
+ *usable_protocols |= of13_up;
+ } else {
+ /* CFI bit is valid for a usable protocol:
+ * eventually return true */
+ ok = true;
+ }
+ }
+
+ return ok;
+}
+
+static enum ofperr ofpacts_check__(struct ofpact[], size_t ofpacts_len,
+ struct flow *, ofp_port_t max_ports,
+ uint8_t table_id, uint8_t n_tables,
+ enum ofputil_protocol *usable_protocols,
+ ovs_be16 *of13_vlan_tci);
+
/* May modify flow->dl_type, flow->nw_proto and flow->vlan_tci,
* caller must restore them.
*
+ * May also modify of13_vlan_tci which the caller should discard. On the
+ * first call to ofpact_check__() of13_vlan_tci should be set to
+ * flow->vlan_tci
+ *
* Modifies some actions, filling in fields that could not be properly set
* without context. */
static enum ofperr
ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
struct flow *flow, ofp_port_t max_ports,
- uint8_t table_id, uint8_t n_tables)
+ uint8_t table_id, uint8_t n_tables, ovs_be16 *of13_vlan_tci)
{
const struct ofpact_enqueue *enqueue;
const struct mf_field *mf;
@@ -1920,12 +2013,13 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
* OpenFlow 1.1+ if need be. */
ofpact_get_SET_VLAN_VID(a)->flow_has_vlan =
(flow->vlan_tci & htons(VLAN_CFI)) == htons(VLAN_CFI);
- if (!(flow->vlan_tci & htons(VLAN_CFI)) &&
- !ofpact_get_SET_VLAN_VID(a)->push_vlan_if_needed) {
- inconsistent_match(usable_protocols);
+ if (!ofpact_get_SET_VLAN_VID(a)->push_vlan_if_needed) {
+ ofpact_check_vlan(usable_protocols, flow->vlan_tci,
+ *of13_vlan_tci, true);
}
/* Temporary mark that we have a vlan tag. */
flow->vlan_tci |= htons(VLAN_CFI);
+ *of13_vlan_tci |= htons(VLAN_CFI);
return 0;
case OFPACT_SET_VLAN_PCP:
@@ -1933,29 +2027,31 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
* OpenFlow 1.1+ if need be. */
ofpact_get_SET_VLAN_PCP(a)->flow_has_vlan =
(flow->vlan_tci & htons(VLAN_CFI)) == htons(VLAN_CFI);
- if (!(flow->vlan_tci & htons(VLAN_CFI)) &&
- !ofpact_get_SET_VLAN_PCP(a)->push_vlan_if_needed) {
- inconsistent_match(usable_protocols);
+ if (!ofpact_get_SET_VLAN_PCP(a)->push_vlan_if_needed) {
+ ofpact_check_vlan(usable_protocols, flow->vlan_tci,
+ *of13_vlan_tci, true);
}
/* Temporary mark that we have a vlan tag. */
flow->vlan_tci |= htons(VLAN_CFI);
+ *of13_vlan_tci |= htons(VLAN_CFI);
return 0;
case OFPACT_STRIP_VLAN:
- if (!(flow->vlan_tci & htons(VLAN_CFI))) {
- inconsistent_match(usable_protocols);
- }
+ ofpact_check_vlan(usable_protocols, flow->vlan_tci, *of13_vlan_tci,
+ true);
/* Temporary mark that we have no vlan tag. */
- flow->vlan_tci = htons(0);
+ *of13_vlan_tci = flow->vlan_tci = htons(0);
return 0;
case OFPACT_PUSH_VLAN:
- if (flow->vlan_tci & htons(VLAN_CFI)) {
+ if (!ofpact_check_vlan(usable_protocols, flow->vlan_tci,
+ *of13_vlan_tci, false)) {
/* Multiple VLAN headers not supported. */
return OFPERR_OFPBAC_BAD_TAG;
}
/* Temporary mark that we have a vlan tag. */
flow->vlan_tci |= htons(VLAN_CFI);
+ *of13_vlan_tci |= htons(VLAN_CFI);
return 0;
case OFPACT_SET_ETH_SRC:
@@ -2012,9 +2108,9 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
mf = ofpact_get_SET_FIELD(a)->field;
/* Require OXM_OF_VLAN_VID to have an existing VLAN header. */
if (!mf_are_prereqs_ok(mf, flow) ||
- (mf->id == MFF_VLAN_VID && !(flow->vlan_tci & htons(VLAN_CFI)))) {
- VLOG_WARN_RL(&rl, "set_field %s lacks correct prerequisities",
- mf->name);
+ (mf->id == MFF_VLAN_VID &&
+ !ofpact_check_vlan(usable_protocols, flow->vlan_tci,
+ *of13_vlan_tci, true))) {
return OFPERR_OFPBAC_MATCH_INCONSISTENT;
}
/* Remember if we saw a vlan tag in the flow to aid translating to
@@ -2025,6 +2121,7 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
/* The set field may add or remove the vlan tag,
* Mark the status temporarily. */
flow->vlan_tci = ofpact_get_SET_FIELD(a)->value.be16;
+ *of13_vlan_tci = ofpact_get_SET_FIELD(a)->value.be16;
}
return 0;
@@ -2071,6 +2168,13 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
* Thus nothing can be assumed about the network protocol.
* Temporarily mark that we have no nw_proto. */
flow->nw_proto = 0;
+
+ /* In the case of OpenFlow1.3+ the MPLS LSE is pushed before
+ * any VLAN tags which were previously present immediately
+ * after the VLAN header.
+ * Temporarily mark that there is no VLAN tag in the case
+ * of OpenFlow1.3+ */
+ *of13_vlan_tci = htons(0);
return 0;
case OFPACT_POP_MPLS:
@@ -2091,8 +2195,9 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
* consistency of an action set. */
struct ofpact_nest *on = ofpact_get_WRITE_ACTIONS(a);
enum ofputil_protocol p = *usable_protocols;
- return ofpacts_check(on->actions, ofpact_nest_get_action_len(on),
- flow, max_ports, table_id, n_tables, &p);
+ return ofpacts_check__(on->actions, ofpact_nest_get_action_len(on),
+ flow, max_ports, table_id, n_tables, &p,
+ of13_vlan_tci);
}
case OFPACT_WRITE_METADATA:
@@ -2123,23 +2228,21 @@ ofpact_check__(enum ofputil_protocol *usable_protocols, struct ofpact *a,
}
}
-/* Checks that the 'ofpacts_len' bytes of actions in 'ofpacts' are
- * appropriate for a packet with the prerequisites satisfied by 'flow' in a
- * switch with no more than 'max_ports' ports.
- *
- * If 'ofpacts' and 'flow' are inconsistent with one another, un-sets in
- * '*usable_protocols' the protocols that forbid the inconsistency. (An
- * example of an inconsistency between match and actions is a flow that does
- * not match on an MPLS Ethertype but has an action that pops an MPLS label.)
+/* May modify flow->dl_type, flow->nw_proto and flow->vlan_tci,
+ * caller must restore them.
*
- * May annotate ofpacts with information gathered from the 'flow'.
+ * May also modify of13_vlan_tci which the caller should discard. On the
+ * first call to ofpacts_check__() of13_vlan_tci should be set to
+ * flow->vlan_tci
*
- * May temporarily modify 'flow', but restores the changes before returning. */
-enum ofperr
-ofpacts_check(struct ofpact ofpacts[], size_t ofpacts_len,
- struct flow *flow, ofp_port_t max_ports,
- uint8_t table_id, uint8_t n_tables,
- enum ofputil_protocol *usable_protocols)
+ * Modifies some actions, filling in fields that could not be properly set
+ * without context. */
+static enum ofperr
+ofpacts_check__(struct ofpact ofpacts[], size_t ofpacts_len,
+ struct flow *flow, ofp_port_t max_ports,
+ uint8_t table_id, uint8_t n_tables,
+ enum ofputil_protocol *usable_protocols,
+ ovs_be16 *of13_vlan_tci)
{
struct ofpact *a;
ovs_be16 dl_type = flow->dl_type;
@@ -2149,10 +2252,19 @@ ofpacts_check(struct ofpact ofpacts[], size_t ofpacts_len,
OFPACT_FOR_EACH (a, ofpacts, ofpacts_len) {
error = ofpact_check__(usable_protocols, a, flow,
- max_ports, table_id, n_tables);
+ max_ports, table_id, n_tables,
+ of13_vlan_tci);
if (error) {
break;
}
+ /* XXX
+ * OF1.3 tag order is not currently implemented.
+ * The following line effectively disables the
+ * use of 'of13_vlan_tci' to check OF1.3+ tag order
+ * consistency. This means that pre-OF1.3+ is always used.
+ * This line should be removed by a subequent
+ * patch which enables the use of OF1.3+ tag order */
+ *of13_vlan_tci = flow->vlan_tci;
}
/* Restore fields that may have been modified. */
flow->dl_type = dl_type;
@@ -2161,6 +2273,30 @@ ofpacts_check(struct ofpact ofpacts[], size_t ofpacts_len,
return error;
}
+/* Checks that the 'ofpacts_len' bytes of actions in 'ofpacts' are
+ * appropriate for a packet with the prerequisites satisfied by 'flow' in a
+ * switch with no more than 'max_ports' ports.
+ *
+ * If 'ofpacts' and 'flow' are inconsistent with one another, un-sets in
+ * '*usable_protocols' the protocols that forbid the inconsistency. (An
+ * example of an inconsistency between match and actions is a flow that does
+ * not match on an MPLS Ethertype but has an action that pops an MPLS label.)
+ *
+ * May annotate ofpacts with information gathered from the 'flow'.
+ *
+ * May temporarily modify 'flow', but restores the changes before returning. */
+enum ofperr
+ofpacts_check(struct ofpact ofpacts[], size_t ofpacts_len,
+ struct flow *flow, ofp_port_t max_ports,
+ uint8_t table_id, uint8_t n_tables,
+ enum ofputil_protocol *usable_protocols)
+{
+ ovs_be16 of13_vlan_tci = flow->vlan_tci;
+
+ return ofpacts_check__(ofpacts, ofpacts_len, flow, max_ports, table_id,
+ n_tables, usable_protocols, &of13_vlan_tci);
+}
+
/* Like ofpacts_check(), but reports inconsistencies as
* OFPERR_OFPBAC_MATCH_INCONSISTENT rather than clearing bits. */
enum ofperr
--
1.8.4
--
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