ovn-controller: Add 'put_dhcpv6_opts' action in ovn-controller

This patch adds a new OVN action 'put_dhcpv6_opts' to support native
DHCPv6 in OVN.

ovn-controller parses this action and adds a NXT_PACKET_IN2
OF flow with 'pause' flag set and the DHCPv6 options stored in
'userdata' field.

When the valid DHCPv6 packet is received by ovn-controller, it frames a
new DHCPv6 reply packet with the DHCPv6 options present in the
'userdata' field and resumes the packet and stores 1 in the 1-bit subfield.
If the packet is invalid, it resumes the packet without any modifying and
stores 0 in the 1-bit subfield.

Eg. reg0[3] = put_dhcpv6_opts(ia_addr = aef0::4, server_id = 00:00:00:00:10:02,
                     dns_server = {ae70::1,ae70::2}....)

A new 'DHCPv6_Options' table is added in SB DB which stores
the supported DHCPv6 options with DHCPv6 code and type. ovn-northd is
expected to popule this table.

Upcoming patch will add logical flows using this action.

Signed-off-by: Numan Siddique <[email protected]>
Signed-off-by: Ben Pfaff <[email protected]>

include/ovn/actions.h

@@ -90,6 +90,15 @@ enum action_opcode {
      *     MFF_ETH_SRC = mac
      */
     ACTION_OPCODE_PUT_ND,
+
+    /* "result = put_dhcpv6_opts(option, ...)".
+     *
+     * Arguments follow the action_header, in this format:
+     *   - A 32-bit or 64-bit OXM header designating the result field.
+     *   - A 32-bit integer specifying a bit offset within the result field.
+     *   - Any number of DHCPv6 options.
+     */
+    ACTION_OPCODE_PUT_DHCPV6_OPTS,
 };
 
 /* Header. */
@@ -107,6 +116,9 @@ struct action_params {
     /* hmap of 'struct dhcp_opts_map'  to support 'put_dhcp_opts' action */
     const struct hmap *dhcp_opts;
 
+    /* hmap of 'struct dhcp_opts_map'  to support 'put_dhcpv6_opts' action */
+    const struct hmap *dhcpv6_opts;
+
     /* Looks up logical port 'port_name'.  If found, stores its port number in
      * '*portp' and returns true; otherwise, returns false. */
     bool (*lookup_port)(const void *aux, const char *port_name,

ovn/controller/lflow.c

@@ -218,6 +218,7 @@ static void consider_logical_flow(const struct lport_index *lports,
                                   struct group_table *group_table,
                                   const struct simap *ct_zones,
                                   struct hmap *dhcp_opts_p,
+                                  struct hmap *dhcpv6_opts_p,
                                   uint32_t *conj_id_ofs_p);
 
 static bool
@@ -271,17 +272,25 @@ add_logical_flows(struct controller_ctx *ctx, const struct lport_index *lports,
     }
 
     struct hmap dhcp_opts = HMAP_INITIALIZER(&dhcp_opts);
+    struct hmap dhcpv6_opts = HMAP_INITIALIZER(&dhcpv6_opts);
     const struct sbrec_dhcp_options *dhcp_opt_row;
     SBREC_DHCP_OPTIONS_FOR_EACH(dhcp_opt_row, ctx->ovnsb_idl) {
         dhcp_opt_add(&dhcp_opts, dhcp_opt_row->name, dhcp_opt_row->code,
                      dhcp_opt_row->type);
     }
 
+
+    const struct sbrec_dhcpv6_options *dhcpv6_opt_row;
+    SBREC_DHCPV6_OPTIONS_FOR_EACH(dhcpv6_opt_row, ctx->ovnsb_idl) {
+       dhcp_opt_add(&dhcpv6_opts, dhcpv6_opt_row->name, dhcpv6_opt_row->code,
+                    dhcpv6_opt_row->type);
+    }
+
     if (full_logical_flow_processing) {
         SBREC_LOGICAL_FLOW_FOR_EACH (lflow, ctx->ovnsb_idl) {
             consider_logical_flow(lports, mcgroups, lflow, local_datapaths,
                                   patched_datapaths, group_table, ct_zones,
-                                  &dhcp_opts, &conj_id_ofs);
+                                  &dhcp_opts, &dhcpv6_opts, &conj_id_ofs);
         }
         full_logical_flow_processing = false;
     } else {
@@ -299,12 +308,13 @@ add_logical_flows(struct controller_ctx *ctx, const struct lport_index *lports,
                 consider_logical_flow(lports, mcgroups, lflow,
                                       local_datapaths, patched_datapaths,
                                       group_table, ct_zones,
-                                      &dhcp_opts, &conj_id_ofs);
+                                      &dhcp_opts, &dhcpv6_opts, &conj_id_ofs);
             }
         }
     }
 
     dhcp_opts_destroy(&dhcp_opts);
+    dhcp_opts_destroy(&dhcpv6_opts);
 }
 
 static void
@@ -316,6 +326,7 @@ consider_logical_flow(const struct lport_index *lports,
                       struct group_table *group_table,
                       const struct simap *ct_zones,
                       struct hmap *dhcp_opts_p,
+                      struct hmap *dhcpv6_opts_p,
                       uint32_t *conj_id_ofs_p)
 {
     /* Determine translation of logical table IDs to physical table IDs. */
@@ -388,6 +399,7 @@ consider_logical_flow(const struct lport_index *lports,
     struct action_params ap = {
         .symtab = &symtab,
         .dhcp_opts = dhcp_opts_p,
+        .dhcpv6_opts = dhcpv6_opts_p,
         .lookup_port = lookup_port_cb,
         .aux = &aux,
         .ct_zones = ct_zones,