Plugin infrastructure improvements

This patch replaces requirement for vlib_plugin_register function
in the plugin so file and introduces new macro:

VLIB_PLUGIN_REGISTER () = {
  .version = "version string",
  .version_required = "requred version",
  .default_disabled = 1,
  .early_init = "early_init_function_name",
};

Plugin will nor be loaded if .default_disabled is set to 1
unless explicitely enabled in startup.conf.

If .verstion_required is set, plugin will not be loaded if there
is version mismatch between plugin and vpp. This can be bypassed
by setting "skip-version-check" for specific plugin.

If .early-init string is present, plugin loader will try to resolve
this specific symbol in the plugin namespace and make a function call.

Following startup.conf configuration is added:

plugins {
  path /path/to/plugin/directory
  plugin ila_plugin.so { enable skip-version-check }
  plugin acl_plugin.so { disable }
}

Change-Id: I706c691dd34d94ffe9e02b59831af8859a95f061
Signed-off-by: Damjan Marion <damarion@cisco.com>

16 files changed, 367 insertions, 210 deletions

diff --git a/src/plugins/acl/acl.c b/src/plugins/acl/acl.c
index f4db2013769..85c9113b25b 100644
--- a/src/plugins/acl/acl.c
+++ b/src/plugins/acl/acl.c
@@ -22,6 +22,7 @@
 
 #include <vnet/l2/l2_classify.h>
 #include <vnet/classify/input_acl.h>
+#include <vpp/app/version.h>
 
 #include <vlibapi/api.h>
 #include <vlibmemory/api.h>
@@ -128,29 +129,11 @@ _(MACIP_ACL_INTERFACE_ADD_DEL, macip_acl_interface_add_del) \
 _(MACIP_ACL_DUMP, macip_acl_dump) \
 _(MACIP_ACL_INTERFACE_GET, macip_acl_interface_get)
 
-/*
- * This routine exists to convince the vlib plugin framework that
- * we haven't accidentally copied a random .dll into the plugin directory.
- *
- * Also collects global variable pointers passed from the vpp engine
- */
-
-clib_error_t *
-vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
-		      int from_early_init)
-{
-  acl_main_t *am = &acl_main;
-  clib_error_t *error = 0;
-
-  am->vlib_main = vm;
-  am->vnet_main = h->vnet_main;
-  am->ethernet_main = h->ethernet_main;
-
-  l2sess_vlib_plugin_register(vm, h, from_early_init);
-
-  return error;
-}
-
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
 
 static void
 vl_api_acl_plugin_get_version_t_handler (vl_api_acl_plugin_get_version_t * mp)
diff --git a/src/plugins/acl/acl.h b/src/plugins/acl/acl.h
index afc9b289cee..62046788660 100644
--- a/src/plugins/acl/acl.h
+++ b/src/plugins/acl/acl.h
@@ -17,7 +17,6 @@
 
 #include <vnet/vnet.h>
 #include <vnet/ip/ip.h>
-#include <vnet/ethernet/ethernet.h>
 #include <vnet/l2/l2_output.h>
 
 
@@ -139,7 +138,6 @@ typedef struct {
   /* convenience */
   vlib_main_t * vlib_main;
   vnet_main_t * vnet_main;
-  ethernet_main_t * ethernet_main;
 } acl_main_t;
 
 extern acl_main_t acl_main;
diff --git a/src/plugins/acl/l2sess.c b/src/plugins/acl/l2sess.c
index cc9bde4417d..b0385be13df 100644
--- a/src/plugins/acl/l2sess.c
+++ b/src/plugins/acl/l2sess.c
@@ -31,19 +31,6 @@
 #include <vnet/l2/l2_input.h>
 
 void
-l2sess_vlib_plugin_register (vlib_main_t * vm, void* hh,
-		      int from_early_init)
-{
-  l2sess_main_t *sm = &l2sess_main;
-  vnet_plugin_handoff_t * h = hh;
-  memset (sm, 0, sizeof (*sm));
-
-  sm->vlib_main = vm;
-  sm->vnet_main = h->vnet_main;
-  sm->ethernet_main = h->ethernet_main;
-}
-
-void
 l2sess_init_next_features_input (vlib_main_t * vm, l2sess_main_t * sm)
 {
 #define _(node_name, node_var, is_out, is_ip6, is_track) \
diff --git a/src/plugins/acl/l2sess.h b/src/plugins/acl/l2sess.h
index db899917113..888b53011dd 100644
--- a/src/plugins/acl/l2sess.h
+++ b/src/plugins/acl/l2sess.h
@@ -132,7 +132,6 @@ foreach_l2sess_node
     /* convenience */
     vlib_main_t * vlib_main;
     vnet_main_t * vnet_main;
-    ethernet_main_t * ethernet_main;
 
     /* Counter(s) */
     u64 counter_attempted_delete_free_session;
diff --git a/src/plugins/flowperpkt/flowperpkt.c b/src/plugins/flowperpkt/flowperpkt.c
index cc35159906d..6b292eef3cc 100644
--- a/src/plugins/flowperpkt/flowperpkt.c
+++ b/src/plugins/flowperpkt/flowperpkt.c
@@ -24,6 +24,7 @@
  */
 
 #include <vnet/vnet.h>
+#include <vpp/app/version.h>
 #include <vnet/plugin/plugin.h>
 #include <flowperpkt/flowperpkt.h>
 
@@ -479,30 +480,11 @@ static void *vl_api_flowperpkt_tx_interface_add_del_t_print
 #define foreach_flowperpkt_plugin_api_msg                           \
 _(FLOWPERPKT_TX_INTERFACE_ADD_DEL, flowperpkt_tx_interface_add_del)
 
-/**
- * @brief plugin-api required function
- * @param vm vlib_main_t * vlib main data structure pointer
- * @param h vlib_plugin_handoff_t * handoff structure
- * @param from_early_init int notused
- *
- * <em>Notes:</em>
- * This routine exists to convince the vlib plugin framework that
- * we haven't accidentally copied a random .dll into the plugin directory.
- *
- * Also collects global variable pointers passed from the vpp engine
- */
-clib_error_t *
-vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
-		      int from_early_init)
-{
-  flowperpkt_main_t *fm = &flowperpkt_main;
-  clib_error_t *error = 0;
-
-  fm->vlib_main = vm;
-  fm->vnet_main = h->vnet_main;
-
-  return error;
-}
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
 
 static clib_error_t *
 flowperpkt_tx_interface_add_del_feature_command_fn (vlib_main_t * vm,
@@ -627,6 +609,8 @@ flowperpkt_init (vlib_main_t * vm)
   u32 num_threads;
   u8 *name;
 
+  fm->vnet_main = vnet_get_main ();
+
   /* Construct the API name */
   name = format (0, "flowperpkt_%08x%c", api_version, 0);
 
diff --git a/src/plugins/ila/ila.c b/src/plugins/ila/ila.c
index 336f4cf560c..e0f3907f5d7 100644
--- a/src/plugins/ila/ila.c
+++ b/src/plugins/ila/ila.c
@@ -18,6 +18,7 @@
 #include <vnet/ip/lookup.h>
 #include <vnet/dpo/dpo.h>
 #include <vnet/fib/fib_table.h>
+#include <vpp/app/version.h>
 
 static ila_main_t ila_main;
 
@@ -821,14 +822,11 @@ ila_interface (u32 sw_if_index, u8 disable)
   return 0;
 }
 
-clib_error_t *
-vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
-		      int from_early_init)
-{
-  clib_error_t *error = 0;
-
-  return error;
-}
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
 
 u8 *format_ila_dpo (u8 * s, va_list * va)
 {
diff --git a/src/plugins/ioam/encap/ip6_ioam_trace.c b/src/plugins/ioam/encap/ip6_ioam_trace.c
index 3a6758cd859..a836dfe817b 100644
--- a/src/plugins/ioam/encap/ip6_ioam_trace.c
+++ b/src/plugins/ioam/encap/ip6_ioam_trace.c
@@ -16,6 +16,7 @@
 #include <vnet/vnet.h>
 #include <vnet/pg/pg.h>
 #include <vppinfra/error.h>
+#include <vpp/app/version.h>
 
 #include <vnet/ip/ip6.h>
 #include <vnet/ip/ip6_hop_by_hop.h>
@@ -349,18 +350,11 @@ VLIB_CLI_COMMAND (ip6_show_ioam_trace_cmd, static) = {
 };
 /* *INDENT-ON* */
 
-/*
- * This routine exists to convince the vlib plugin framework that
- * we haven't accidentally copied a random .dll into the plugin directory.
- *
- * Also collects global variable pointers passed from the vpp engine
- */
-clib_error_t *
-vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
-		      int from_early_init)
-{
-  return 0;
-}
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
 
 static clib_error_t *
 ip6_hop_by_hop_ioam_trace_init (vlib_main_t * vm)
diff --git a/src/plugins/lb/lb.c b/src/plugins/lb/lb.c
index 1d9b987095b..dc3f5be1b1b 100644
--- a/src/plugins/lb/lb.c
+++ b/src/plugins/lb/lb.c
@@ -15,6 +15,7 @@
 
 #include <lb/lb.h>
 #include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
 #include <vnet/api_errno.h>
 
 //GC runs at most once every so many seconds
@@ -730,15 +731,11 @@ int lb_vip_del(u32 vip_index)
   return 0;
 }
 
-clib_error_t *
-vlib_plugin_register (vlib_main_t * vm,
-                      vnet_plugin_handoff_t * h,
-                      int from_early_init)
-{
-  clib_error_t *error = 0;
-  return error;
-}
-
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
 
 u8 *format_lb_dpo (u8 * s, va_list * va)
 {
diff --git a/src/plugins/sixrd/sixrd.c b/src/plugins/sixrd/sixrd.c
index 66e631a2b6a..71fc181f2b7 100644
--- a/src/plugins/sixrd/sixrd.c
+++ b/src/plugins/sixrd/sixrd.c
@@ -19,6 +19,7 @@
 #include <vnet/fib/fib_table.h>
 #include <vnet/fib/ip6_fib.h>
 #include <vnet/adj/adj.h>
+#include <vpp/app/version.h>
 
 /*
  * This code supports the following sixrd modes:
@@ -340,27 +341,19 @@ VLIB_CLI_COMMAND(show_sixrd_stats_command, static) = {
   .function = show_sixrd_stats_command_fn,
 };
 
-/* 
- * This routine exists to convince the vlib plugin framework that
- * we haven't accidentally copied a random .dll into the plugin directory.
- *
- * Also collects global variable pointers passed from the vpp engine
- */
-clib_error_t * 
-vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
-                      int from_early_init)
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
+
+static clib_error_t * sixrd_init (vlib_main_t * vm)
 {
-  clib_error_t * error = 0;
   sixrd_main_t *mm = &sixrd_main;
 
   mm->vnet_main = vnet_get_main();
   mm->vlib_main = vm;
 
-  return error;
-}
-
-static clib_error_t * sixrd_init (vlib_main_t * vm)
-{
   sixrd_dpo_module_init ();
 
   return (NULL);
diff --git a/src/plugins/snat/snat.c b/src/plugins/snat/snat.c
index 0fcd6ce8606..750cc925d7f 100644
--- a/src/plugins/snat/snat.c
+++ b/src/plugins/snat/snat.c
@@ -28,6 +28,7 @@
 #include <vlibapi/api.h>
 #include <vlibmemory/api.h>
 #include <vlibsocket/api.h>
+#include <vpp/app/version.h>
 
 snat_main_t snat_main;
 
@@ -129,27 +130,11 @@ VNET_FEATURE_INIT (ip4_snat_out2in_fast, static) = {
   .runs_before = VNET_FEATURES ("ip4-lookup"),
 };
 
-
-/* 
- * This routine exists to convince the vlib plugin framework that
- * we haven't accidentally copied a random .dll into the plugin directory.
- *
- * Also collects global variable pointers passed from the vpp engine
- */
-
-clib_error_t * 
-vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h,
-                      int from_early_init)
-{
-  snat_main_t * sm = &snat_main;
-  clib_error_t * error = 0;
-
-  sm->vlib_main = vm;
-  sm->vnet_main = h->vnet_main;
-  sm->ethernet_main = h->ethernet_main;
-
-  return error;
-}
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+};
+/* *INDENT-ON* */
 
 /*$$$$$ move to an installed header file */
 #if (1 || CLIB_DEBUG > 0)       /* "trust, but verify" */
diff --git a/src/plugins/snat/snat.h b/src/plugins/snat/snat.h
index 32dc9f9e0a6..39cbd3f8e0f 100644
--- a/src/plugins/snat/snat.h
+++ b/src/plugins/snat/snat.h
@@ -233,7 +233,6 @@ typedef struct {
   vnet_main_t * vnet_main;
   ip4_main_t * ip4_main;
   ip_lookup_main_t * ip4_lookup_main;
-  ethernet_main_t * ethernet_main;  
   api_main_t * api_main;
 } snat_main_t;
 
diff --git a/src/vlib/unix/main.c b/src/vlib/unix/main.c
index 562778e0e5d..a04d9f9c6ab 100644
--- a/src/vlib/unix/main.c
+++ b/src/vlib/unix/main.c
@@ -503,6 +503,14 @@ vlib_unix_main (int argc, char *argv[])
   vm->heap_base = clib_mem_get_heap ();
   ASSERT (vm->heap_base);
 
+  unformat_init_command_line (&input, (char **) vm->argv);
+  if ((e = vlib_plugin_config (vm, &input)))
+    {
+      clib_error_report (e);
+      return 1;
+    }
+  unformat_free (&input);
+
   i = vlib_plugin_early_init (vm);
   if (i)
     return i;
diff --git a/src/vlib/unix/plugin.c b/src/vlib/unix/plugin.c
index 40399090983..4aba95c863e 100644
--- a/src/vlib/unix/plugin.c
+++ b/src/vlib/unix/plugin.c
@@ -16,29 +16,16 @@
  */
 
 #include <vlib/unix/plugin.h>
+#include <vppinfra/elf.h>
 #include <dlfcn.h>
 #include <dirent.h>
 
 plugin_main_t vlib_plugin_main;
 
-void
-vlib_set_get_handoff_structure_cb (void *cb)
-{
-  plugin_main_t *pm = &vlib_plugin_main;
-  pm->handoff_structure_get_cb = cb;
-}
-
-static void *
-vnet_get_handoff_structure (void)
-{
-  void *(*fp) (void);
-
-  fp = vlib_plugin_main.handoff_structure_get_cb;
-  if (fp == 0)
-    return 0;
-  else
-    return (*fp) ();
-}
+char *vlib_plugin_path __attribute__ ((weak));
+char *vlib_plugin_path = "";
+char *vlib_plugin_app_version __attribute__ ((weak));
+char *vlib_plugin_app_version = "";
 
 void *
 vlib_get_plugin_symbol (char *plugin_name, char *symbol_name)
@@ -54,13 +41,99 @@ vlib_get_plugin_symbol (char *plugin_name, char *symbol_name)
   return dlsym (pi->handle, symbol_name);
 }
 
+static char *
+str_array_to_vec (char *array, int len)
+{
+  char c, *r = 0;
+  int n = 0;
+
+  do
+    {
+      c = array[n];
+      vec_add1 (r, c);
+    }
+  while (c && ++n < len);
+
+  if (c)
+    vec_add1 (r, 0);
+
+  return r;
+}
+
 static int
 load_one_plugin (plugin_main_t * pm, plugin_info_t * pi, int from_early_init)
 {
-  void *handle, *register_handle;
-  clib_error_t *(*fp) (vlib_main_t *, void *, int);
+  void *handle;
   clib_error_t *error;
-  void *handoff_structure;
+  elf_main_t em = { 0 };
+  elf_section_t *section;
+  u8 *data;
+  char *version_required;
+  vlib_plugin_registration_t *reg;
+  plugin_config_t *pc = 0;
+  uword *p;
+
+  if (elf_read_file (&em, (char *) pi->filename))
+    return -1;
+
+  error = elf_get_section_by_name (&em, ".vlib_plugin_registration",
+				   &section);
+  if (error)
+    {
+      clib_warning ("Not a plugin: %s\n", (char *) pi->name);
+      return -1;
+    }
+
+  data = elf_get_section_contents (&em, section->index, 1);
+  reg = (vlib_plugin_registration_t *) data;
+
+  if (vec_len (data) != sizeof (*reg))
+    {
+      clib_warning ("vlib_plugin_registration size mismatch in plugin %s\n",
+		    (char *) pi->name);
+      goto error;
+    }
+
+  p = hash_get_mem (pm->config_index_by_name, pi->name);
+  if (p)
+    {
+      pc = vec_elt_at_index (pm->configs, p[0]);
+      if (pc->is_disabled)
+	{
+	  clib_warning ("Plugin disabled: %s", pi->name);
+	  goto error;
+	}
+      if (reg->default_disabled && pc->is_enabled == 0)
+	{
+	  clib_warning ("Plugin disabled: %s (default)", pi->name);
+	  goto error;
+	}
+    }
+  else if (reg->default_disabled)
+    {
+      clib_warning ("Plugin disabled: %s (default)", pi->name);
+      goto error;
+    }
+
+  version_required = str_array_to_vec ((char *) &reg->version_required,
+				       sizeof (reg->version_required));
+
+  if ((strlen (version_required) > 0) &&
+      (strncmp (vlib_plugin_app_version, version_required,
+		strlen (version_required))))
+    {
+      clib_warning ("Plugin %s version mismatch: %s != %s",
+		    pi->name, vlib_plugin_app_version, reg->version_required);
+      if (!(pc && pc->skip_version_check == 1))
+	{
+	  vec_free (version_required);
+	  goto error;
+	}
+    }
+
+  vec_free (version_required);
+  vec_free (data);
+  elf_main_free (&em);
 
   handle = dlopen ((char *) pi->filename, RTLD_LAZY);
 
@@ -77,35 +150,47 @@ load_one_plugin (plugin_main_t * pm, plugin_info_t * pi, int from_early_init)
 
   pi->handle = handle;
 
+  reg = dlsym (pi->handle, "vlib_plugin_registration");
 
-  register_handle = dlsym (pi->handle, "vlib_plugin_register");
-  if (register_handle == 0)
+  if (reg == 0)
     {
-      dlclose (handle);
-      clib_warning ("Plugin missing vlib_plugin_register: %s\n",
-		    (char *) pi->name);
-      return 1;
+      /* This should never happen unless somebody chagnes registration macro */
+      clib_warning ("Missing plugin registration in plugin '%s'", pi->name);
+      os_exit (1);
     }
 
-  fp = register_handle;
-
-  handoff_structure = vnet_get_handoff_structure ();
+  pi->reg = reg;
+  pi->version = str_array_to_vec ((char *) &reg->version,
+				  sizeof (reg->version));
 
-  if (handoff_structure == 0)
-    error = clib_error_return (0, "handoff structure callback returned 0");
-  else
-    error = (*fp) (pm->vlib_main, handoff_structure, from_early_init);
-
-  if (error)
+  if (reg && reg->early_init)
     {
-      clib_error_report (error);
-      dlclose (handle);
-      return 1;
+      clib_error_t *(*ei) (vlib_main_t *);
+      void *h;
+
+      h = dlsym (pi->handle, reg->early_init);
+      if (h)
+	{
+	  ei = h;
+	  error = (*ei) (pm->vlib_main);
+	  if (error)
+	    {
+	      clib_error_report (error);
+	      os_exit (1);
+	    }
+	}
+      else
+	clib_warning ("Plugin %s: early init function %s set but not found",
+		      (char *) pi->name, reg->early_init);
     }
 
   clib_warning ("Loaded plugin: %s", pi->name);
 
   return 0;
+error:
+  vec_free (data);
+  elf_main_free (&em);
+  return -1;
 }
 
 static u8 **
@@ -215,23 +300,16 @@ vlib_load_new_plugins (plugin_main_t * pm, int from_early_init)
   return 0;
 }
 
-char *vlib_plugin_path __attribute__ ((weak));
-char *vlib_plugin_path = "";
-char *vlib_plugin_name_filter __attribute__ ((weak));
-char *vlib_plugin_name_filter = 0;
-
 int
 vlib_plugin_early_init (vlib_main_t * vm)
 {
   plugin_main_t *pm = &vlib_plugin_main;
 
-  pm->plugin_path = format (0, "%s%c", vlib_plugin_path, 0);
+  if (pm->plugin_path == 0)
+    pm->plugin_path = format (0, "%s%c", vlib_plugin_path, 0);
 
   clib_warning ("plugin path %s", pm->plugin_path);
 
-  if (vlib_plugin_name_filter)
-    pm->plugin_name_filter = format (0, "%s%c", vlib_plugin_name_filter, 0);
-
   pm->plugin_by_name_hash = hash_create_string (0, sizeof (uword));
   pm->vlib_main = vm;
 
@@ -245,19 +323,24 @@ vlib_plugins_show_cmd_fn (vlib_main_t * vm,
   plugin_main_t *pm = &vlib_plugin_main;
   u8 *s = 0;
   u8 *key = 0;
-  uword *value = 0;
+  uword value = 0;
   int index = 1;
+  plugin_info_t *pi;
 
-  s = format (s, " Plugin path is: %s\n", pm->plugin_path);
-  if (vlib_plugin_name_filter)
-    s = format (s, " Plugin filter: %s\n", vlib_plugin_name_filter);
+  s = format (s, " Plugin path is: %s\n\n", pm->plugin_path);
+  s = format (s, "     %-41s%s\n", "Plugin", "Version");
 
-  s = format (s, " Plugins loaded: \n");
+  /* *INDENT-OFF* */
   hash_foreach_mem (key, value, pm->plugin_by_name_hash,
-		    {
-		    if (key != 0)
-		    s = format (s, "  %d.%s\n", index, key); index++;}
-  );
+    {
+      if (key != 0)
+        {
+          pi = vec_elt_at_index (pm->plugin_info, value);
+          s = format (s, "%3d. %-40s %s\n", index, key, pi->version);
+	  index++;
+        }
+    });
+  /* *INDENT-ON* */
 
   vlib_cli_output (vm, "%v", s);
   vec_free (s);
@@ -273,6 +356,148 @@ VLIB_CLI_COMMAND (plugins_show_cmd, static) =
 };
 /* *INDENT-ON* */
 
+static clib_error_t *
+config_one_plugin (vlib_main_t * vm, char *name, unformat_input_t * input)
+{
+  plugin_main_t *pm = &vlib_plugin_main;
+  plugin_config_t *pc;
+  clib_error_t *error = 0;
+  uword *p;
+  int is_enable = 0;
+  int is_disable = 0;
+  int skip_version_check = 0;
+
+  if (pm->config_index_by_name == 0)
+    pm->config_index_by_name = hash_create_string (0, sizeof (uword));
+
+  p = hash_get_mem (pm->config_index_by_name, name);
+
+  if (p)
+    {
+      error = clib_error_return (0, "plugin '%s' already configured", name);
+      goto done;
+    }
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "enable"))
+	is_enable = 1;
+      else if (unformat (input, "disable"))
+	is_disable = 1;
+      else if (unformat (input, "skip-version-check"))
+	skip_version_check = 1;
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, input);
+	  goto done;
+	}
+    }
+
+  if (is_enable && is_disable)
+    {
+      error = clib_error_return (0, "please specify either enable or disable"
+				 " for plugin '%s'", name);
+      goto done;
+    }
+
+  vec_add2 (pm->configs, pc, 1);
+  hash_set_mem (pm->config_index_by_name, name, pc - pm->configs);
+  pc->is_enabled = is_enable;
+  pc->is_disabled = is_disable;
+  pc->skip_version_check = skip_version_check;
+  pc->name = name;
+
+done:
+  return error;
+}
+
+clib_error_t *
+vlib_plugin_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  plugin_main_t *pm = &vlib_plugin_main;
+  clib_error_t *error = 0;
+  unformat_input_t in;
+
+  unformat_init (&in, 0, 0);
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      u8 *s, *v;
+      if (unformat (input, "%s %v", &s, &v))
+	{
+	  if (strncmp ((const char *) s, "plugins", 8) == 0)
+	    {
+	      if (vec_len (in.buffer) > 0)
+		vec_add1 (in.buffer, ' ');
+	      vec_add (in.buffer, v, vec_len (v));
+	    }
+	}
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, input);
+	  goto done;
+	}
+
+      vec_free (v);
+      vec_free (s);
+    }
+done:
+  input = &in;
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      unformat_input_t sub_input;
+      u8 *s = 0;
+      if (unformat (input, "path %s", &s))
+	pm->plugin_path = s;
+      else if (unformat (input, "plugin %s %U", &s,
+			 unformat_vlib_cli_sub_input, &sub_input))
+	{
+	  error = config_one_plugin (vm, (char *) s, &sub_input);
+	  unformat_free (&sub_input);
+	  if (error)
+	    goto done2;
+	}
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, input);
+	  {
+	    vec_free (s);
+	    goto done2;
+	  }
+	}
+    }
+
+done2:
+  unformat_free (&in);
+  return error;
+}
+
+/* discard whole 'plugins' section, as it is already consumed prior to
+   plugin load */
+static clib_error_t *
+plugins_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  u8 *junk;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "%s", &junk))
+	{
+	  vec_free (junk);
+	  return 0;
+	}
+      else
+	return clib_error_return (0, "unknown input '%U'",
+				  format_unformat_error, input);
+    }
+  return 0;
+}
+
+VLIB_CONFIG_FUNCTION (plugins_config, "plugins");
+
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vlib/unix/plugin.h b/src/vlib/unix/plugin.h
index 1c74cdd241b..01fec3564fc 100644
--- a/src/vlib/unix/plugin.h
+++ b/src/vlib/unix/plugin.h
@@ -56,7 +56,14 @@
  * vlib_load_new_plugins().
  */
 
-
+/* *INDENT-OFF* */
+typedef CLIB_PACKED(struct {
+  u8 default_disabled;
+  const char version[32];
+  const char version_required[32];
+  const char *early_init;
+}) vlib_plugin_registration_t;
+/* *INDENT-ON* */
 
 typedef struct
 {
@@ -64,10 +71,22 @@ typedef struct
   u8 *filename;
   struct stat file_info;
   void *handle;
+
+  /* plugin registration */
+  vlib_plugin_registration_t *reg;
+  char *version;
 } plugin_info_t;
 
 typedef struct
 {
+  char *name;
+  u8 is_disabled;
+  u8 is_enabled;
+  u8 skip_version_check;
+} plugin_config_t;
+
+typedef struct
+{
   /* loaded plugin info */
   plugin_info_t *plugin_info;
   uword *plugin_by_name_hash;
@@ -76,8 +95,9 @@ typedef struct
   u8 *plugin_path;
   u8 *plugin_name_filter;
 
-  /* handoff structure get callback */
-  void *handoff_structure_get_cb;
+  /* plugin configs and hash by name */
+  plugin_config_t *configs;
+  uword *config_index_by_name;
 
   /* usual */
   vlib_main_t *vlib_main;
@@ -85,10 +105,15 @@ typedef struct
 
 extern plugin_main_t vlib_plugin_main;
 
+clib_error_t *vlib_plugin_config (vlib_main_t * vm, unformat_input_t * input);
 int vlib_plugin_early_init (vlib_main_t * vm);
 int vlib_load_new_plugins (plugin_main_t * pm, int from_early_init);
 void *vlib_get_plugin_symbol (char *plugin_name, char *symbol_name);
 
+#define VLIB_PLUGIN_REGISTER() \
+  vlib_plugin_registration_t vlib_plugin_registration \
+  __attribute__((__section__(".vlib_plugin_registration")))
+
 #endif /* __included_plugin_h__ */
 
 /*
diff --git a/src/vnet/plugin/plugin.h b/src/vnet/plugin/plugin.h
index a14a5932b50..6e1a3264654 100644
--- a/src/vnet/plugin/plugin.h
+++ b/src/vnet/plugin/plugin.h
@@ -20,13 +20,6 @@
 #include <vnet/pg/pg.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vppinfra/error.h>
-
-/* Pointers to Genuine Vnet data structures handed to plugin .dll's */
-typedef struct {
-  vnet_main_t * vnet_main;
-  ethernet_main_t * ethernet_main;
-} vnet_plugin_handoff_t;
-
-void * vnet_get_handoff_structure (void);
+#include <vlib/unix/plugin.h>
 
 #endif /* included_vnet_plugin_h */
diff --git a/src/vpp/vnet/main.c b/src/vpp/vnet/main.c
index a252b84663a..4a96ca94321 100644
--- a/src/vpp/vnet/main.c
+++ b/src/vpp/vnet/main.c
@@ -18,7 +18,7 @@
 #include <vlib/unix/unix.h>
 #include <vnet/plugin/plugin.h>
 #include <vnet/ethernet/ethernet.h>
-
+#include <vpp/app/version.h>
 #include <vpp/api/vpe_msg_enum.h>
 
 
@@ -39,16 +39,7 @@ vpe_main_init (vlib_main_t * vm)
  * Load plugins from /usr/lib/vpp_plugins by default
  */
 char *vlib_plugin_path = "/usr/lib/vpp_plugins";
-
-void *
-vnet_get_handoff_structure (void)
-{
-  static vnet_plugin_handoff_t _rv, *rv = &_rv;
-
-  rv->vnet_main = vnet_get_main ();
-  rv->ethernet_main = &ethernet_main;
-  return (void *) rv;
-}
+char *vlib_plugin_app_version = VPP_BUILD_VER;
 
 int
 main (int argc, char *argv[])
@@ -59,7 +50,6 @@ main (int argc, char *argv[])
   uword main_heap_size = (1ULL << 30);
   u8 *sizep;
   u32 size;
-  void vlib_set_get_handoff_structure_cb (void *cb);
 
 #if __x86_64__
   CLIB_UNUSED (const char *msg)
@@ -206,7 +196,6 @@ defaulted:
 #if DPDK == 0
       unix_physmem_init (vm, 0 /* fail_if_physical_memory_not_present */ );
 #endif
-      vlib_set_get_handoff_structure_cb (&vnet_get_handoff_structure);
       return vlib_unix_main (argc, argv);
     }
   else