[ovs-dev] [RFC v2 02/11] ovn: Add bridge mappings to ovn-controller.

[Russell Bryant]

Add a new OVN configuration entry in the Open_vSwitch database called
"ovn-bridge-mappings".  This allows the configuration of mappings
between a physical network name and an OVS bridge that provides
connectivity to that network.

For example, if you wanted to configure "physnet1" to map to "br-eth0"
and "physnet2" to map to "br-eth1", the configuration would be:

  $ ovs-vsctl set open . \
  > external-ids:ovn-bridge-mappings=physnet1:br-eth0,physnet2:br-eth1

In this patch, the configuration option is only parsed and validated
to make sure the referenced bridges actually exist.  Later patches
will make use of the bridge mappings.

Signed-off-by: Russell Bryant <rbryant at redhat.com>
---
 ovn/controller/ovn-controller.c | 61 ++++++++++++++++++++++++++++++++++++++++-
 ovn/controller/ovn-controller.h |  7 +++++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/ovn/controller/ovn-controller.c b/ovn/controller/ovn-controller.c
index fda1534..31f66a9 100644
--- a/ovn/controller/ovn-controller.c
+++ b/ovn/controller/ovn-controller.c
@@ -33,6 +33,8 @@
 #include "poll-loop.h"
 #include "fatal-signal.h"
 #include "lib/vswitch-idl.h"
+#include "hash.h"
+#include "hmap.h"
 #include "smap.h"
 #include "stream.h"
 #include "stream-ssl.h"
@@ -85,6 +87,50 @@ get_bridge(struct controller_ctx *ctx, const char *name)
     return NULL;
 }
 
+static int
+parse_bridge_mappings(struct controller_ctx *ctx, const char *bridge_mappings_)
+{
+    char *cur, *next, *start;
+    int res = 0;
+
+    next = start = xstrdup(bridge_mappings_);
+
+    while ((cur = strsep(&next, ","))) {
+        char *network, *bridge = cur;
+        const struct ovsrec_bridge *ovs_bridge;
+
+        network = strsep(&bridge, ":");
+        if (!bridge || !*network || !*bridge) {
+            VLOG_ERR("Invalid ovn-bridge-mappings configuration: '%s'", bridge_mappings_);
+            res = -1;
+            break;
+        }
+
+        VLOG_DBG("Bridge mapping - network '%s' to bridge '%s'", network, bridge);
+
+        ovs_bridge = get_bridge(ctx, bridge);
+        if (!ovs_bridge) {
+            VLOG_WARN("Bridge '%s' not found for network '%s'", bridge, network);
+            res = -1;
+            break;
+        }
+
+        if (create_patch_ports(ctx, ovs_bridge)) {
+            VLOG_WARN("Failed to create patch ports between '%s' and '%s'",
+                    ctx->br_int_name, bridge);
+            res = -1;
+            break;
+        }
+
+        smap_add(&ctx->localnet_mappings, network, bridge);
+        smap_add(&ctx->bridge_mappings, bridge, network);
+    }
+
+    free(start);
+
+    return res;
+}
+
 /* Retrieve the OVN integration bridge from the "external-ids:ovn-bridge"
  * key, the remote location from the "external-ids:ovn-remote" key, and
  * the chassis name from the "external-ids:system-id" key in the
@@ -106,7 +152,7 @@ get_core_config(struct controller_ctx *ctx)
 
     while (1) {
         const struct ovsrec_bridge *br_int;
-        const char *remote, *system_id, *br_int_name;
+        const char *remote, *system_id, *br_int_name, *bridge_mappings;
 
         ovsdb_idl_run(ctx->ovs_idl);
 
@@ -135,6 +181,17 @@ get_core_config(struct controller_ctx *ctx)
             goto try_again;
         }
 
+        smap_init(&ctx->bridge_mappings);
+        smap_init(&ctx->localnet_mappings);
+        bridge_mappings = smap_get(&cfg->external_ids, "ovn-bridge-mappings");
+        if (bridge_mappings) {
+            int res = parse_bridge_mappings(ctx, bridge_mappings);
+            if (res) {
+                VLOG_INFO("Error parsing ovn-bridge-mappings.  Waiting ...");
+                goto try_again;
+            }
+        }
+
         ovnsb_remote = xstrdup(remote);
         ctx->chassis_id = xstrdup(system_id);
         return;
@@ -260,6 +317,8 @@ main(int argc, char *argv[])
     free(ctx.chassis_id);
     free(ovnsb_remote);
     free(ovs_remote);
+    smap_destroy(&ctx.bridge_mappings);
+    smap_destroy(&ctx.localnet_mappings);
 
     exit(retval);
 }
diff --git a/ovn/controller/ovn-controller.h b/ovn/controller/ovn-controller.h
index 6f98658..98bf248 100644
--- a/ovn/controller/ovn-controller.h
+++ b/ovn/controller/ovn-controller.h
@@ -19,6 +19,8 @@
 
 #include "ovn/lib/ovn-sb-idl.h"
 
+struct smap;
+
 struct controller_ctx {
     char *chassis_id;               /* ID for this chassis. */
     char *br_int_name;              /* Name of local integration bridge. */
@@ -26,6 +28,11 @@ struct controller_ctx {
     struct ovsdb_idl *ovs_idl;
 
     const struct ovsrec_bridge *br_int;
+
+    /* Map bridges to local nets from ovn-bridge-mappings */
+    struct smap bridge_mappings;
+    /* Map local nets to bridges from ovn-bridge-mappings */
+    struct smap localnet_mappings;
 };
 
 static inline const struct sbrec_chassis *
-- 
2.4.3