ovn: add is_chassis_resident match expression component

This patch introduces a new match expression component
is_chassis_resident().  Unlike match expression comparisons,
is_chassis_resident is not pushed down to OpenFlow.  It is a
conditional that is evaluated in the controller during expr_simplify(),
when it is replaced by a boolean expression.  The is_chassis_resident
conditional evaluates to "true" when the specified string identifies a
port name that is resident on this controller chassis, i.e., the
corresponding southbound database Port_Binding has a chassis column
that matches this chassis.  Otherwise it evaluates to "false".

This allows higher level features to specify flows that are only
installed on some chassis rather than on all chassis with the
corresponding datapath.

Suggested-by: Ben Pfaff <blp@ovn.org>
Signed-off-by: Mickey Spiegel <mickeys.dev@gmail.com>
Acked-by: Ben Pfaff <blp@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>

include/ovn/expr.h

@@ -292,6 +292,15 @@ enum expr_type {
     EXPR_T_AND,                 /* Logical AND of 2 or more subexpressions. */
     EXPR_T_OR,                  /* Logical OR of 2 or more subexpressions. */
     EXPR_T_BOOLEAN,             /* True or false constant. */
+    EXPR_T_CONDITION,           /* Conditional to be evaluated in the
+                                 * controller during expr_simplify(),
+                                 * prior to constructing OpenFlow matches. */
+};
+
+/* Expression condition type. */
+enum expr_cond_type {
+    EXPR_COND_CHASSIS_RESIDENT, /* Check if specified logical port name is
+                                 * resident on the controller chassis. */
 };
 
 /* Relational operator. */
@@ -349,6 +358,14 @@ struct expr {
 
         /* EXPR_T_BOOLEAN. */
         bool boolean;
+
+        /* EXPR_T_CONDITION. */
+        struct {
+            enum expr_cond_type type;
+            bool not;
+            /* XXX Should arguments for conditions be generic? */
+            char *string;
+        } cond;
     };
 };
 
@@ -375,7 +392,10 @@ void expr_destroy(struct expr *);
 
 struct expr *expr_annotate(struct expr *, const struct shash *symtab,
                            char **errorp);
-struct expr *expr_simplify(struct expr *);
+struct expr *expr_simplify(struct expr *,
+                           bool (*is_chassis_resident)(const void *c_aux,
+                                                       const char *port_name),
+                           const void *c_aux);
 struct expr *expr_normalize(struct expr *);
 
 bool expr_honors_invariants(const struct expr *);

ovn/controller/lflow.c

@@ -50,12 +50,18 @@ struct lookup_port_aux {
     const struct sbrec_datapath_binding *dp;
 };
 
+struct condition_aux {
+    const struct lport_index *lports;
+    const struct sbrec_chassis *chassis;
+};
+
 static void consider_logical_flow(const struct lport_index *lports,
                                   const struct mcgroup_index *mcgroups,
                                   const struct sbrec_logical_flow *lflow,
                                   const struct hmap *local_datapaths,
                                   struct group_table *group_table,
                                   const struct simap *ct_zones,
+                                  const struct sbrec_chassis *chassis,
                                   struct hmap *dhcp_opts,
                                   struct hmap *dhcpv6_opts,
                                   uint32_t *conj_id_ofs,
@@ -84,6 +90,16 @@ lookup_port_cb(const void *aux_, const char *port_name, unsigned int *portp)
     return false;
 }
 
+static bool
+is_chassis_resident_cb(const void *c_aux_, const char *port_name)
+{
+    const struct condition_aux *c_aux = c_aux_;
+
+    const struct sbrec_port_binding *pb
+        = lport_lookup_by_name(c_aux->lports, port_name);
+    return pb && pb->chassis && pb->chassis == c_aux->chassis;
+}
+
 static bool
 is_switch(const struct sbrec_datapath_binding *ldp)
 {
@@ -98,6 +114,7 @@ add_logical_flows(struct controller_ctx *ctx, const struct lport_index *lports,
                   const struct hmap *local_datapaths,
                   struct group_table *group_table,
                   const struct simap *ct_zones,
+                  const struct sbrec_chassis *chassis,
                   const struct shash *addr_sets,
                   struct hmap *flow_table)
 {
@@ -121,7 +138,7 @@ add_logical_flows(struct controller_ctx *ctx, const struct lport_index *lports,
 
     SBREC_LOGICAL_FLOW_FOR_EACH (lflow, ctx->ovnsb_idl) {
         consider_logical_flow(lports, mcgroups, lflow, local_datapaths,
-                              group_table, ct_zones,
+                              group_table, ct_zones, chassis,
                               &dhcp_opts, &dhcpv6_opts, &conj_id_ofs,
                               addr_sets, flow_table);
     }
@@ -137,6 +154,7 @@ consider_logical_flow(const struct lport_index *lports,
                       const struct hmap *local_datapaths,
                       struct group_table *group_table,
                       const struct simap *ct_zones,
+                      const struct sbrec_chassis *chassis,
                       struct hmap *dhcp_opts,
                       struct hmap *dhcpv6_opts,
                       uint32_t *conj_id_ofs,
@@ -235,7 +253,8 @@ consider_logical_flow(const struct lport_index *lports,
         return;
     }
 
-    expr = expr_simplify(expr);
+    struct condition_aux cond_aux = { lports, chassis };
+    expr = expr_simplify(expr, is_chassis_resident_cb, &cond_aux);
     expr = expr_normalize(expr);
     uint32_t n_conjs = expr_to_matches(expr, lookup_port_cb, &aux,
                                        &matches);
@@ -356,16 +375,18 @@ add_neighbor_flows(struct controller_ctx *ctx,
 /* Translates logical flows in the Logical_Flow table in the OVN_SB database
  * into OpenFlow flows.  See ovn-architecture(7) for more information. */
 void
-lflow_run(struct controller_ctx *ctx, const struct lport_index *lports,
+lflow_run(struct controller_ctx *ctx,
+          const struct sbrec_chassis *chassis,
+          const struct lport_index *lports,
           const struct mcgroup_index *mcgroups,
           const struct hmap *local_datapaths,
           struct group_table *group_table,
           const struct simap *ct_zones,
           const struct shash *addr_sets,
           struct hmap *flow_table)
 {
-    add_logical_flows(ctx, lports, mcgroups, local_datapaths,
-                      group_table, ct_zones, addr_sets, flow_table);
+    add_logical_flows(ctx, lports, mcgroups, local_datapaths, group_table,
+                      ct_zones, chassis, addr_sets, flow_table);
     add_neighbor_flows(ctx, lports, flow_table);
 }
 

ovn/controller/lflow.h

@@ -40,6 +40,7 @@ struct group_table;
 struct hmap;
 struct lport_index;
 struct mcgroup_index;
+struct sbrec_chassis;
 struct simap;
 struct uuid;
 
@@ -61,7 +62,9 @@ struct uuid;
 #define LOG_PIPELINE_LEN 16
 
 void lflow_init(void);
-void lflow_run(struct controller_ctx *, const struct lport_index *,
+void lflow_run(struct controller_ctx *,
+               const struct sbrec_chassis *chassis,
+               const struct lport_index *,
                const struct mcgroup_index *,
                const struct hmap *local_datapaths,
                struct group_table *group_table,

ovn/controller/ovn-controller.c

@@ -621,8 +621,9 @@ main(int argc, char *argv[])
                 commit_ct_zones(br_int, &pending_ct_zones);
 
                 struct hmap flow_table = HMAP_INITIALIZER(&flow_table);
-                lflow_run(&ctx, &lports, &mcgroups, &local_datapaths,
-                          &group_table, &ct_zones, &addr_sets, &flow_table);
+                lflow_run(&ctx, chassis, &lports, &mcgroups,
+                          &local_datapaths, &group_table, &ct_zones,
+                          &addr_sets, &flow_table);
 
                 physical_run(&ctx, mff_ovn_geneve,
                              br_int, chassis, &ct_zones, &lports,