Consolidate DHCP v4 and V6 implementation. No functional change intended

The DHCP proxy and VSS information maintained by VPP is the same for v4 and v6, so we can manage this state using the same code.
Packet handling is cleary different, so this is kept separate.

Change-Id: I10f10cc1f7f19debcd4c4b099c6de64e56bb0c69
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 248 insertions, 0 deletions

diff --git a/src/vnet/dhcp/dhcp_proxy.h b/src/vnet/dhcp/dhcp_proxy.h
new file mode 100644
index 00000000000..c0d79c41af6
--- /dev/null
+++ b/src/vnet/dhcp/dhcp_proxy.h
@@ -0,0 +1,248 @@
+/*
+ * dhcp_proxy.h: DHCP v4 & v6 proxy common functions/types
+ *
+ * Copyright (c) 2013 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef included_dhcp_proxy_h
+#define included_dhcp_proxy_h
+
+#include <vnet/vnet.h>
+#include <vnet/dhcp/dhcp4_packet.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ip/ip4.h>
+#include <vnet/ip/ip4_packet.h>
+#include <vnet/pg/pg.h>
+#include <vnet/ip/format.h>
+#include <vnet/ip/udp.h>
+
+typedef enum {
+#define dhcp_proxy_error(n,s) DHCP_PROXY_ERROR_##n,
+#include <vnet/dhcp/dhcp4_proxy_error.def>
+#undef dhcp_proxy_error
+  DHCP_PROXY_N_ERROR,
+} dhcp_proxy_error_t;
+
+typedef enum {
+#define dhcpv6_proxy_error(n,s) DHCPV6_PROXY_ERROR_##n,
+#include <vnet/dhcp/dhcp6_proxy_error.def>
+#undef dhcpv6_proxy_error
+  DHCPV6_PROXY_N_ERROR,
+} dhcpv6_proxy_error_t;
+
+
+/**
+ * @brief The Virtual Sub-net Selection information for a given RX FIB
+ */
+typedef struct dhcp_vss_t_ {
+    /**
+     * @brief ?? RFC doesn't say
+     */
+    u32 oui;
+    /**
+     * @brief VPN-ID
+     */
+    u32 fib_id;
+} dhcp_vss_t;
+
+/**
+ * @brief A DHCP proxy server represenation
+ */
+typedef struct dhcp_server_t_ {
+    /**
+     * @brief The address of the DHCP server to which to relay the client's
+     *        messages
+     */
+    ip46_address_t dhcp_server;
+
+    /**
+     * @brief The source address to use in relayed messaes
+     */
+    ip46_address_t dhcp_src_address;
+
+    /**
+     * @brief The FIB index (not the external Table-ID) in which the server
+     *        is reachable.
+     */
+    u32 server_fib_index;
+
+    /**
+     * @brief The FIB index (not the external Table-ID) in which the client
+     *        is resides.
+     */
+    u32 rx_fib_index;
+} dhcp_server_t;
+
+#define DHCP_N_PROTOS (FIB_PROTOCOL_IP6 + 1)
+
+/**
+ * @brief Collection of global DHCP proxy data
+ */
+typedef struct {
+  /* Pool of DHCP servers */
+  dhcp_server_t *dhcp_servers[DHCP_N_PROTOS];
+
+  /* Pool of selected DHCP server. Zero is the default server */
+  u32 * dhcp_server_index_by_rx_fib_index[DHCP_N_PROTOS];
+
+  /* to drop pkts in server-to-client direction */
+  u32 error_drop_node_index;
+
+  dhcp_vss_t *vss[DHCP_N_PROTOS];
+
+  /* hash lookup specific vrf_id -> option 82 vss suboption  */
+  u32 *vss_index_by_rx_fib_index[DHCP_N_PROTOS];
+
+} dhcp_proxy_main_t;
+
+extern dhcp_proxy_main_t dhcp_proxy_main;
+
+/**
+ * @brief Send the details of a proxy session to the API client during a dump
+ */
+void dhcp_send_details (fib_protocol_t proto,
+                        void *opaque,
+                        u32 context,
+                        const ip46_address_t *server,
+                        const ip46_address_t *src,
+                        u32 server_fib_id,
+                        u32 rx_fib_id,
+                        u32 vss_fib_id,
+                        u32 vss_oui);
+
+/**
+ * @brief Show (on CLI) a VSS config during a show walk
+ */
+int dhcp_vss_show_walk (dhcp_vss_t *vss,
+                        u32 rx_table_id,
+                        void *ctx);
+
+/**
+ * @brief Configure/set a new VSS info
+ */
+int dhcp_proxy_set_vss(fib_protocol_t proto,
+                       u32 vrf_id,
+                       u32 oui,
+                       u32 fib_id,
+                       int is_del);
+
+/**
+ * @brief Dump the proxy configs to the API
+ */
+void dhcp_proxy_dump(fib_protocol_t proto,
+                     void *opaque,
+                     u32 context);
+
+/**
+ * @brief Add a new DHCP proxy server configuration.
+ * @return 1 is the config is new,
+ *         0 otherwise (implying a modify of an existing)
+ */
+int dhcp_proxy_server_add(fib_protocol_t proto,
+                          ip46_address_t *addr,
+                          ip46_address_t *src_address,
+                          u32 rx_fib_iindex,
+                          u32 server_table_id);
+
+/**
+ * @brief Delete a DHCP proxy config
+ * @return 0 is deleted, otherwise an error code
+ */
+int dhcp_proxy_server_del(fib_protocol_t proto,
+                          u32 rx_fib_index);
+
+/**
+ * @brief Callback function invoked for each DHCP proxy entry
+ *  return 0 to break the walk, non-zero otherwise.
+ */
+typedef int (*dhcp_proxy_walk_fn_t)(dhcp_server_t *server,
+                                    void *ctx);
+
+/**
+ * @brief Walk/Visit each DHCP proxy server
+ */
+void dhcp_proxy_walk(fib_protocol_t proto,
+                     dhcp_proxy_walk_fn_t fn,
+                     void *ctx);
+
+/**
+ * @brief Callback function invoked for each DHCP VSS entry
+ *  return 0 to break the walk, non-zero otherwise.
+ */
+typedef int (*dhcp_vss_walk_fn_t)(dhcp_vss_t *server,
+                                  u32 rx_table_id,
+                                  void *ctx);
+
+/**
+ * @brief Walk/Visit each DHCP proxy VSS
+ */
+void dhcp_vss_walk(fib_protocol_t proto,
+                   dhcp_vss_walk_fn_t fn,
+                   void *ctx);
+
+/**
+ * @brief Get the VSS data for the FIB index
+ */
+static inline dhcp_vss_t *
+dhcp_get_vss_info (dhcp_proxy_main_t *dm,
+                   u32 rx_fib_index,
+                   fib_protocol_t proto)
+{
+  dhcp_vss_t *v = NULL;
+
+  if (vec_len(dm->vss_index_by_rx_fib_index[proto]) > rx_fib_index &&
+      dm->vss_index_by_rx_fib_index[proto][rx_fib_index] != ~0)
+  {
+      v = pool_elt_at_index (
+              dm->vss[proto],
+              dm->vss_index_by_rx_fib_index[proto][rx_fib_index]);
+  }
+
+  return (v);
+}
+
+/**
+ * @brief Get the DHCP proxy server data for the FIB index
+ */
+static inline dhcp_server_t *
+dhcp_get_server (dhcp_proxy_main_t *dm,
+                 u32 rx_fib_index,
+                 fib_protocol_t proto)
+{
+  dhcp_server_t *s = NULL;
+
+  if (vec_len(dm->dhcp_server_index_by_rx_fib_index[proto]) > rx_fib_index &&
+      dm->dhcp_server_index_by_rx_fib_index[proto][rx_fib_index] != ~0)
+  {
+      s = pool_elt_at_index (
+              dm->dhcp_servers[proto],
+              dm->dhcp_server_index_by_rx_fib_index[proto][rx_fib_index]);
+  }
+
+  return (s);
+}
+
+int dhcp6_proxy_set_server (ip46_address_t *addr,
+                            ip46_address_t *src_addr,
+                            u32 rx_table_id,
+                            u32 server_table_id,
+                            int is_del);
+int dhcp4_proxy_set_server (ip46_address_t *addr,
+                            ip46_address_t *src_addr,
+                            u32 rx_table_id,
+                            u32 server_table_id,
+                            int is_del);
+
+#endif /* included_dhcp_proxy_h */