flow: New FLOW_WC_SEQ build assertion.

Changing "struct flow" or its wildcards requires minor adjustments
in many places in the code.  This patch adds a new FLOW_WC_SEQ
sequence number which when incremented will cause build assertion
failures aiding the developer in finding code which needs to
change.

diff --git a/lib/classifier.c b/lib/classifier.c
index 730cae8..d1f9d5d 100644 (file)
--- a/lib/classifier.c
+++ b/lib/classifier.c
@@ -467,6 +467,8 @@ cls_rule_format(const struct cls_rule *rule, struct ds *s)
 
     int i;
 
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
+
     if (rule->priority != OFP_DEFAULT_PRIORITY) {
         ds_put_format(s, "priority=%d,", rule->priority);
     }
@@ -1138,7 +1140,7 @@ flow_equal_except(const struct flow *a, const struct flow *b,
     const flow_wildcards_t wc = wildcards->wildcards;
     int i;
 
-    BUILD_ASSERT_DECL(FLOW_SIG_SIZE == 100 + FLOW_N_REGS * 4);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
 
     for (i = 0; i < FLOW_N_REGS; i++) {
         if ((a->regs[i] ^ b->regs[i]) & wildcards->reg_masks[i]) {
@@ -1182,7 +1184,7 @@ zero_wildcards(struct flow *flow, const struct flow_wildcards *wildcards)
     const flow_wildcards_t wc = wildcards->wildcards;
     int i;
 
-    BUILD_ASSERT_DECL(FLOW_SIG_SIZE == 100 + 4 * FLOW_N_REGS);
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
 
     for (i = 0; i < FLOW_N_REGS; i++) {
         flow->regs[i] &= wildcards->reg_masks[i];

diff --git a/lib/flow.h b/lib/flow.h
index ba2d806..d049e7e 100644 (file)
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -33,6 +33,11 @@ struct flow_wildcards;
 struct ofp_match;
 struct ofpbuf;
 
+/* This sequence number should be incremented whenever anything involving flows
+ * or the wildcarding of flows changes.  This will cause build assertion
+ * failures in places which likely need to be updated. */
+#define FLOW_WC_SEQ 1
+
 #define FLOW_N_REGS 4
 BUILD_ASSERT_DECL(FLOW_N_REGS <= NXM_NX_MAX_REGS);
 
@@ -70,6 +75,9 @@ BUILD_ASSERT_DECL(offsetof(struct flow, nd_target) == FLOW_SIG_SIZE - 16);
 BUILD_ASSERT_DECL(sizeof(((struct flow *)0)->nd_target) == 16);
 BUILD_ASSERT_DECL(sizeof(struct flow) == FLOW_SIG_SIZE + FLOW_PAD_SIZE);
 
+/* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
+BUILD_ASSERT_DECL(FLOW_SIG_SIZE == 116 && FLOW_WC_SEQ == 1);
+
 int flow_extract(struct ofpbuf *, ovs_be64 tun_id, uint16_t in_port,
                  struct flow *);
 void flow_extract_stats(const struct flow *flow, struct ofpbuf *packet,
@@ -126,6 +134,9 @@ typedef unsigned int OVS_BITWISE flow_wildcards_t;
 #define FWW_ND_TARGET   ((OVS_FORCE flow_wildcards_t) (1 << 11))
 #define FWW_ALL         ((OVS_FORCE flow_wildcards_t) (((1 << 12)) - 1))
 
+/* Remember to update FLOW_WC_SEQ when adding or removing FWW_*. */
+BUILD_ASSERT_DECL(FWW_ALL == ((1 << 12) - 1) && FLOW_WC_SEQ == 1);
+
 /* Information on wildcards for a flow, as a supplement to "struct flow".
  *
  * Note that the meaning of 1-bits in 'wildcards' is opposite that of 1-bits in
@@ -142,6 +153,9 @@ struct flow_wildcards {
     uint16_t zero;              /* Padding field set to zero. */
 };
 
+/* Remember to update FLOW_WC_SEQ when updating struct flow_wildcards. */
+BUILD_ASSERT_DECL(sizeof(struct flow_wildcards) == 72 && FLOW_WC_SEQ == 1);
+
 void flow_wildcards_init_catchall(struct flow_wildcards *);
 void flow_wildcards_init_exact(struct flow_wildcards *);
 

diff --git a/lib/nx-match.c b/lib/nx-match.c
index e698cc6..ecc284e 100644 (file)
--- a/lib/nx-match.c
+++ b/lib/nx-match.c
@@ -162,6 +162,8 @@ parse_nxm_entry(struct cls_rule *rule, const struct nxm_field *f,
     struct flow_wildcards *wc = &rule->wc;
     struct flow *flow = &rule->flow;
 
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
+
     switch (f->index) {
         /* Metadata. */
     case NFI_NXM_OF_IN_PORT:
@@ -706,6 +708,8 @@ nx_put_match(struct ofpbuf *b, const struct cls_rule *cr)
     int match_len;
     int i;
 
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
+
     /* Metadata. */
     if (!(wc & FWW_IN_PORT)) {
         uint16_t in_port = flow->in_port;

diff --git a/lib/ofp-parse.c b/lib/ofp-parse.c
index e6a6af1..c938400 100644 (file)
--- a/lib/ofp-parse.c
+++ b/lib/ofp-parse.c
@@ -613,6 +613,7 @@ parse_protocol(const char *name, const struct protocol **p_out)
     return false;
 }
 
+BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
 #define FIELDS                                              \
     FIELD(F_TUN_ID,      "tun_id",      0)                  \
     FIELD(F_IN_PORT,     "in_port",     FWW_IN_PORT)        \

diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index 71c28b2..b0aeaf4 100644 (file)
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -108,6 +108,8 @@ static const flow_wildcards_t WC_INVARIANTS = 0
 void
 ofputil_wildcard_from_openflow(uint32_t ofpfw, struct flow_wildcards *wc)
 {
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
+
     /* Initialize most of rule->wc. */
     flow_wildcards_init_catchall(wc);
     wc->wildcards = (OVS_FORCE flow_wildcards_t) ofpfw & WC_INVARIANTS;
@@ -800,6 +802,8 @@ ofputil_min_flow_format(const struct cls_rule *rule)
 {
     const struct flow_wildcards *wc = &rule->wc;
 
+    BUILD_ASSERT_DECL(FLOW_WC_SEQ == 1);
+
     /* Only NXM supports separately wildcards the Ethernet multicast bit. */
     if (!(wc->wildcards & FWW_DL_DST) != !(wc->wildcards & FWW_ETH_MCAST)) {
         return NXFF_NXM;