zebra: add module to communicate routes to FPM

Enhance zebra to send routes to the (optional) Forwarding Path Manager
component using the interface defined by fpm/fpm.h.

  * configure.ac

    - Add --enable-fpm flag.

      The FPM-related code in zebra is activated only if the build is
      configured with '--enable-fpm'.

    - Add HAVE_NETLINK automake conditional.

      This allows us to conditionally build netlink-dependent C code.

  * zebra/{rib.h,zebra_rib.c}

    - Add the 'fpm_q_entries' field to the rib_dest_t structure. This
      allows dests to be placed on the fpm queue.

    - Define a couple new rib_dest_t flags that hold FPM-related
      state.

    - Invoke the zfpm_trigger_update() function for a route_node
      whenever the information to be sent to the FPM changes.

    - rib_can_delete_dest(): Return FALSE if we have to update the FPM
      about the given dest. This ensures that the dest is not deleted
      even if there are no ribs hanging off of it.

  * zebra/zebra_fpm.c

    This file holds most of the code for interacting with the FPM.

    - If quagga was configured with '--enable-fpm', periodically try
      to connect to the FPM.

    - When the connection comes up, enqueue all relevent dests to the
      FPM queue.

    - When the FPM socket is readable, dequeue the next rib_dest_t
      from the FPM queue, encode it in to a message and send the
      message to the FPM.

    - When the connection to the FPM goes down, remove all dests from
      the FPM queue, and then start trying to connect to the FPM
      again.

    - Expose the following new operational commands:

      show zebra fpm stats
      clear zebra fpm stats

  * zebra/zebra_fpm_netlink.c

    - zfpm_netlink_encode_route(): Function to encode information
      about a rib_dest_t in netlink format.

  * zebra/zebra_fpm_private.h

    Private header file for the zebra FPM module.

  * zebra/zebra_fpm.h

    Header file exported by zebra FPM module to the rest of zebra.

  * zebra/debug.c

    Add the 'debug zebra fpm' command.

  * zebra/main.c

    Initialize the zebra-FPM code on startup.

  * zebra/misc_null.c

    Add stub for zfpm_trigger_update().

  * zebra/Makefile.am

    - Include new file zebra_fpm.c in build.

    - Include zebra_fpm_netlink.c in build if HAVE_NETLINK is defined.

  * vtysh/Makefile.am

    Include zebra_fpm.c in list of files that define cli commands.

Signed-off-by: Avneesh Sachdev <avneesh@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

configure.ac

@@ -272,6 +272,8 @@ AC_ARG_ENABLE(time-check,
 [  --disable-time-check          disable slow thread warning messages])
 AC_ARG_ENABLE(pcreposix,
 [  --enable-pcreposix          enable using PCRE Posix libs for regex functions])
+AC_ARG_ENABLE(fpm,
+[  --enable-fpm            enable Forwarding Plane Manager support])
 
 if test x"${enable_gcc_ultra_verbose}" = x"yes" ; then
   CFLAGS="${CFLAGS} -W -Wcast-qual -Wstrict-prototypes"
@@ -292,6 +294,10 @@ if test x"${enable_time_check}" != x"no" ; then
   fi
 fi
 
+if test "${enable_fpm}" = "yes"; then
+   AC_DEFINE(HAVE_FPM,,Forwarding Plane Manager support)
+fi
+
 if test "${enable_broken_aliases}" = "yes"; then
   if test "${enable_netlink}" = "yes"
   then
@@ -828,6 +834,7 @@ fi
 AC_SUBST(RT_METHOD)
 AC_SUBST(KERNEL_METHOD)
 AC_SUBST(OTHER_METHOD)
+AM_CONDITIONAL([HAVE_NETLINK], [test "x$netlink" = "xyes"])
 
 dnl --------------------------
 dnl Determine IS-IS I/O method

vtysh/Makefile.am

@@ -33,7 +33,8 @@ vtysh_cmd_FILES = $(top_srcdir)/bgpd/*.c $(top_srcdir)/isisd/*.c \
 		  $(top_srcdir)/zebra/irdp_interface.c \
 		  $(top_srcdir)/zebra/rtadv.c $(top_srcdir)/zebra/zebra_vty.c \
 		  $(top_srcdir)/zebra/zserv.c $(top_srcdir)/zebra/router-id.c \
-		  $(top_srcdir)/zebra/zebra_routemap.c
+		  $(top_srcdir)/zebra/zebra_routemap.c \
+	          $(top_srcdir)/zebra/zebra_fpm.c
 
 vtysh_cmd.c: $(vtysh_cmd_FILES)
 	./$(EXTRA_DIST) $(vtysh_cmd_FILES) > vtysh_cmd.c

zebra/Makefile.am

@@ -19,6 +19,10 @@ ioctl_method = @IOCTL_METHOD@
 otherobj = $(ioctl_method) $(ipforward) $(if_method) $(if_proc) \
 	$(rt_method) $(rtread_method) $(kernel_method) $(other_method)
 
+if HAVE_NETLINK
+othersrc = zebra_fpm_netlink.c
+endif
+
 AM_CFLAGS = $(PICFLAGS)
 AM_LDFLAGS = $(PILDFLAGS)
 
@@ -29,7 +33,8 @@ noinst_PROGRAMS = testzebra
 zebra_SOURCES = \
 	zserv.c main.c interface.c connected.c zebra_rib.c zebra_routemap.c \
 	redistribute.c debug.c rtadv.c zebra_snmp.c zebra_vty.c \
-	irdp_main.c irdp_interface.c irdp_packet.c router-id.c
+	irdp_main.c irdp_interface.c irdp_packet.c router-id.c zebra_fpm.c \
+	$(othersrc)
 
 testzebra_SOURCES = test_main.c zebra_rib.c interface.c connected.c debug.c \
 	zebra_vty.c \

zebra/debug.c

@@ -29,6 +29,7 @@ unsigned long zebra_debug_event;
 unsigned long zebra_debug_packet;
 unsigned long zebra_debug_kernel;
 unsigned long zebra_debug_rib;
+unsigned long zebra_debug_fpm;
 
 DEFUN (show_debugging_zebra,
        show_debugging_zebra_cmd,
@@ -71,6 +72,9 @@ DEFUN (show_debugging_zebra,
   if (IS_ZEBRA_DEBUG_RIB_Q)
     vty_out (vty, "  Zebra RIB queue debugging is on%s", VTY_NEWLINE);
 
+  if (IS_ZEBRA_DEBUG_FPM)
+    vty_out (vty, "  Zebra FPM debugging is on%s", VTY_NEWLINE);
+
   return CMD_SUCCESS;
 }
 
@@ -169,6 +173,17 @@ DEFUN (debug_zebra_rib_q,
   return CMD_SUCCESS;
 }
 
+DEFUN (debug_zebra_fpm,
+       debug_zebra_fpm_cmd,
+       "debug zebra fpm",
+       DEBUG_STR
+       "Zebra configuration\n"
+       "Debug zebra FPM events\n")
+{
+  SET_FLAG (zebra_debug_fpm, ZEBRA_DEBUG_FPM);
+  return CMD_SUCCESS;
+}
+
 DEFUN (no_debug_zebra_events,
        no_debug_zebra_events_cmd,
        "no debug zebra events",
@@ -247,6 +262,18 @@ DEFUN (no_debug_zebra_rib_q,
   return CMD_SUCCESS;
 }
 
+DEFUN (no_debug_zebra_fpm,
+       no_debug_zebra_fpm_cmd,
+       "no debug zebra fpm",
+       NO_STR
+       DEBUG_STR
+       "Zebra configuration\n"
+       "Debug zebra FPM events\n")
+{
+  zebra_debug_fpm = 0;
+  return CMD_SUCCESS;
+}
+
 /* Debug node. */
 struct cmd_node debug_node =
 {
@@ -302,6 +329,11 @@ config_write_debug (struct vty *vty)
       vty_out (vty, "debug zebra rib queue%s", VTY_NEWLINE);
       write++;
     }
+  if (IS_ZEBRA_DEBUG_FPM)
+    {
+      vty_out (vty, "debug zebra fpm%s", VTY_NEWLINE);
+      write++;
+    }
   return write;
 }
 
@@ -312,6 +344,7 @@ zebra_debug_init (void)
   zebra_debug_packet = 0;
   zebra_debug_kernel = 0;
   zebra_debug_rib = 0;
+  zebra_debug_fpm = 0;
 
   install_node (&debug_node, config_write_debug);
 
@@ -325,11 +358,13 @@ zebra_debug_init (void)
   install_element (ENABLE_NODE, &debug_zebra_kernel_cmd);
   install_element (ENABLE_NODE, &debug_zebra_rib_cmd);
   install_element (ENABLE_NODE, &debug_zebra_rib_q_cmd);
+  install_element (ENABLE_NODE, &debug_zebra_fpm_cmd);
   install_element (ENABLE_NODE, &no_debug_zebra_events_cmd);
   install_element (ENABLE_NODE, &no_debug_zebra_packet_cmd);
   install_element (ENABLE_NODE, &no_debug_zebra_kernel_cmd);
   install_element (ENABLE_NODE, &no_debug_zebra_rib_cmd);
   install_element (ENABLE_NODE, &no_debug_zebra_rib_q_cmd);
+  install_element (ENABLE_NODE, &no_debug_zebra_fpm_cmd);
 
   install_element (CONFIG_NODE, &debug_zebra_events_cmd);
   install_element (CONFIG_NODE, &debug_zebra_packet_cmd);
@@ -338,9 +373,11 @@ zebra_debug_init (void)
   install_element (CONFIG_NODE, &debug_zebra_kernel_cmd);
   install_element (CONFIG_NODE, &debug_zebra_rib_cmd);
   install_element (CONFIG_NODE, &debug_zebra_rib_q_cmd);
+  install_element (CONFIG_NODE, &debug_zebra_fpm_cmd);
   install_element (CONFIG_NODE, &no_debug_zebra_events_cmd);
   install_element (CONFIG_NODE, &no_debug_zebra_packet_cmd);
   install_element (CONFIG_NODE, &no_debug_zebra_kernel_cmd);
   install_element (CONFIG_NODE, &no_debug_zebra_rib_cmd);
   install_element (CONFIG_NODE, &no_debug_zebra_rib_q_cmd);
+  install_element (CONFIG_NODE, &no_debug_zebra_fpm_cmd);
 }

zebra/debug.h

@@ -36,6 +36,8 @@
 #define ZEBRA_DEBUG_RIB     0x01
 #define ZEBRA_DEBUG_RIB_Q   0x02
 
+#define ZEBRA_DEBUG_FPM     0x01
+
 /* Debug related macro. */
 #define IS_ZEBRA_DEBUG_EVENT  (zebra_debug_event & ZEBRA_DEBUG_EVENT)
 
@@ -49,10 +51,13 @@
 #define IS_ZEBRA_DEBUG_RIB  (zebra_debug_rib & ZEBRA_DEBUG_RIB)
 #define IS_ZEBRA_DEBUG_RIB_Q  (zebra_debug_rib & ZEBRA_DEBUG_RIB_Q)
 
+#define IS_ZEBRA_DEBUG_FPM (zebra_debug_fpm & ZEBRA_DEBUG_FPM)
+
 extern unsigned long zebra_debug_event;
 extern unsigned long zebra_debug_packet;
 extern unsigned long zebra_debug_kernel;
 extern unsigned long zebra_debug_rib;
+extern unsigned long zebra_debug_fpm;
 
 extern void zebra_debug_init (void);
 

zebra/main.c

@@ -39,6 +39,7 @@
 #include "zebra/router-id.h"
 #include "zebra/irdp.h"
 #include "zebra/rtadv.h"
+#include "zebra/zebra_fpm.h"
 
 /* Zebra instance */
 struct zebra_t zebrad =
@@ -349,6 +350,12 @@ main (int argc, char **argv)
   zebra_snmp_init ();
 #endif /* HAVE_SNMP */
 
+#ifdef HAVE_FPM
+  zfpm_init (zebrad.master, 1, 0);
+#else
+  zfpm_init (zebrad.master, 0, 0);
+#endif
+
   /* Process the configuration file. Among other configuration
   *  directives we can meet those installing static routes. Such
   *  requests will not be executed immediately, but queued in

zebra/misc_null.c

@@ -4,8 +4,15 @@
 #include "zebra/rtadv.h"
 #include "zebra/irdp.h"
 #include "zebra/interface.h"
+#include "zebra/zebra_fpm.h"
 
 void ifstat_update_proc (void) { return; }
 #pragma weak rtadv_config_write = ifstat_update_proc
 #pragma weak irdp_config_write = ifstat_update_proc
 #pragma weak ifstat_update_sysctl = ifstat_update_proc
+
+void
+zfpm_trigger_update (struct route_node *rn, const char *reason)
+{
+  return;
+}

zebra/rib.h

@@ -25,6 +25,7 @@
 
 #include "prefix.h"
 #include "table.h"
+#include "queue.h"
 
 #define DISTANCE_INFINITY  255
 
@@ -116,6 +117,11 @@ typedef struct rib_dest_t_
    */
   u_int32_t flags;
 
+  /*
+   * Linkage to put dest on the FPM processing queue.
+   */
+  TAILQ_ENTRY(rib_dest_t_) fpm_q_entries;
+
 } rib_dest_t;
 
 #define RIB_ROUTE_QUEUED(x)	(1 << (x))
@@ -125,6 +131,18 @@ typedef struct rib_dest_t_
  */
 #define ZEBRA_MAX_QINDEX        (MQ_SIZE - 1)
 
+/*
+ * This flag indicates that a given prefix has been 'advertised' to
+ * the FPM to be installed in the forwarding plane.
+ */
+#define RIB_DEST_SENT_TO_FPM   (1 << (ZEBRA_MAX_QINDEX + 1))
+
+/*
+ * This flag is set when we need to send an update to the FPM about a
+ * dest.
+ */
+#define RIB_DEST_UPDATE_FPM    (1 << (ZEBRA_MAX_QINDEX + 2))
+
 /*
  * Macro to iterate over each route for a destination (prefix).
  */