[ovs-dev] [packet_in v2 16/18] nx-match: Optionally allow unknown NXM headers in nx_pull_match().

[Ethan Jackson]

Future patches will need the ability to skip over unsupported NXM
headers in nx_pull_match().

Signed-off-by: Ethan Jackson <ethan at nicira.com>
---
 lib/nx-match.c        |   13 ++++++++++---
 lib/nx-match.h        |    6 ++++--
 lib/ofp-util.c        |   15 ++++++++-------
 utilities/ovs-ofctl.c |    2 +-
 4 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/lib/nx-match.c b/lib/nx-match.c
index a93a693..3de2363 100644
--- a/lib/nx-match.c
+++ b/lib/nx-match.c
@@ -102,11 +102,14 @@ nx_entry_ok(const void *p, unsigned int match_len)
  * pointers, then the cookie and mask will be stored in them if a
  * "NXM_NX_COOKIE*" match is defined.  Otherwise, 0 is stored in both.
  *
+ * If 'strict' is true, will fail with an error when encountering unknown NXM
+ * headers.
+ *
  * Returns 0 if successful, otherwise an OpenFlow error code.
  */
 int
-nx_pull_match(struct ofpbuf *b, unsigned int match_len, uint16_t priority,
-              struct cls_rule *rule,
+nx_pull_match(struct ofpbuf *b, unsigned int match_len, bool strict,
+              uint16_t priority, struct cls_rule *rule,
               ovs_be64 *cookie, ovs_be64 *cookie_mask)
 {
     uint32_t header;
@@ -133,7 +136,11 @@ nx_pull_match(struct ofpbuf *b, unsigned int match_len, uint16_t priority,
 
         mf = mf_from_nxm_header(header);
         if (!mf) {
-            error = NXM_BAD_TYPE;
+            if (strict) {
+                error = NXM_BAD_TYPE;
+            } else {
+                continue;
+            }
         } else if (!mf_are_prereqs_ok(mf, &rule->flow)) {
             error = NXM_BAD_PREREQ;
         } else if (!mf_is_all_wild(mf, &rule->wc)) {
diff --git a/lib/nx-match.h b/lib/nx-match.h
index c7ee0f8..7093637 100644
--- a/lib/nx-match.h
+++ b/lib/nx-match.h
@@ -17,6 +17,7 @@
 #ifndef NX_MATCH_H
 #define NX_MATCH_H 1
 
+#include <stdbool.h>
 #include <stdint.h>
 #include <sys/types.h>
 #include <netinet/in.h>
@@ -34,8 +35,9 @@ struct nx_action_reg_move;
  * See include/openflow/nicira-ext.h for NXM specification.
  */
 
-int nx_pull_match(struct ofpbuf *, unsigned int match_len, uint16_t priority,
-                  struct cls_rule *, ovs_be64 *cookie, ovs_be64 *cookie_mask);
+int nx_pull_match(struct ofpbuf *, unsigned int match_len, bool strict,
+                  uint16_t priority, struct cls_rule *,
+                  ovs_be64 *cookie, ovs_be64 *cookie_mask);
 int nx_put_match(struct ofpbuf *, const struct cls_rule *,
                  ovs_be64 cookie, ovs_be64 cookie_mask);
 
diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index 6873842..842a843 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -1001,8 +1001,9 @@ ofputil_decode_flow_mod(struct ofputil_flow_mod *fm,
 
         /* Dissect the message. */
         nfm = ofpbuf_pull(&b, sizeof *nfm);
-        error = nx_pull_match(&b, ntohs(nfm->match_len), ntohs(nfm->priority),
-                              &fm->cr, &fm->cookie, &fm->cookie_mask);
+        error = nx_pull_match(&b, ntohs(nfm->match_len), true,
+                              ntohs(nfm->priority), &fm->cr,
+                              &fm->cookie, &fm->cookie_mask);
         if (error) {
             return error;
         }
@@ -1137,7 +1138,7 @@ ofputil_decode_nxst_flow_request(struct ofputil_flow_stats_request *fsr,
     ofpbuf_use_const(&b, oh, ntohs(oh->length));
 
     nfsr = ofpbuf_pull(&b, sizeof *nfsr);
-    error = nx_pull_match(&b, ntohs(nfsr->match_len), 0, &fsr->match,
+    error = nx_pull_match(&b, ntohs(nfsr->match_len), true, 0, &fsr->match,
                           &fsr->cookie, &fsr->cookie_mask);
     if (error) {
         return error;
@@ -1309,8 +1310,8 @@ ofputil_decode_flow_stats_reply(struct ofputil_flow_stats *fs,
                          "claims invalid length %zu", match_len, length);
             return EINVAL;
         }
-        if (nx_pull_match(msg, match_len, ntohs(nfs->priority), &fs->rule,
-                          NULL, NULL)) {
+        if (nx_pull_match(msg, match_len, true, ntohs(nfs->priority),
+                          &fs->rule, NULL, NULL)) {
             return EINVAL;
         }
 
@@ -1472,8 +1473,8 @@ ofputil_decode_flow_removed(struct ofputil_flow_removed *fr,
         ofpbuf_use_const(&b, oh, ntohs(oh->length));
 
         nfr = ofpbuf_pull(&b, sizeof *nfr);
-        error = nx_pull_match(&b, ntohs(nfr->match_len), ntohs(nfr->priority),
-                              &fr->rule, NULL, NULL);
+        error = nx_pull_match(&b, ntohs(nfr->match_len), true,
+                              ntohs(nfr->priority), &fr->rule, NULL, NULL);
         if (error) {
             return error;
         }
diff --git a/utilities/ovs-ofctl.c b/utilities/ovs-ofctl.c
index 044f74c..51dd92f 100644
--- a/utilities/ovs-ofctl.c
+++ b/utilities/ovs-ofctl.c
@@ -1539,7 +1539,7 @@ do_parse_nx_match(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
         match_len = nx_match_from_string(ds_cstr(&in), &nx_match);
 
         /* Convert nx_match to cls_rule. */
-        error = nx_pull_match(&nx_match, match_len, 0, &rule,
+        error = nx_pull_match(&nx_match, match_len, true, 0, &rule,
                               &cookie, &cookie_mask);
         if (!error) {
             char *out;
-- 
1.7.7.1