bgpd: Add new configuration cli for eBGP and iBGP multipath.

There is support to configure this for each (AFI,SAFI), but
currently this configuration is only present for IPv4 unicast:

 maximum-paths [ibgp] <1-255>
 no maximum-paths [ibgp] [<1-255>]

* bgpd/Makefile.am
  * Add bgp_mpath.h and bgp_mpath.c to build
* bgpd/bgp_mpath.h
  * New file for bgp multipath declarations
  * define BGP_DEFAULT_MAXPATHS
* bgpd/bgp_mpath.c
  * bgp_maximum_paths_set(): Configure maximum paths for the given
    afi, safi and bgp instance
  * bgp_maximum_paths_unset(): Return maximum paths configuration to
    the default setting for the given afi, safi and bgp instance
* bgpd/bgp_vty.c
  * Define command strings for above CLI
  * bgp_config_write_maxpaths(): Outputs configuration for the given
    afi, safi and bgp instance
  * Install command elements for IPv4 unicast
* bgpd/bgp_zebra.h
  * bgp_config_write_maxpaths(): External declaration
* bgpd/bgpd.c
  * bgp_create(): Initialize bgp instance to default maximum paths setting
  * bgp_config_write_family(): Output maximum paths configuration
    for the given address family
  * bgp_config_write(): Output maximum paths configuration for
    IPv4 unicast address family
* bgpd/bgpd.h
  * struct bgp: Add storage for maximum paths configuration for
    each afi, safi

1 files changed, 158 insertions, 0 deletions

diff --git a/bgpd/bgp_vty.c b/bgpd/bgp_vty.c
index e7e7dba1..2c44efc2 100644
--- a/bgpd/bgp_vty.c
+++ b/bgpd/bgp_vty.c
@@ -48,6 +48,7 @@ Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 #include "bgpd/bgp_zebra.h"
 #include "bgpd/bgp_table.h"
 #include "bgpd/bgp_vty.h"
+#include "bgpd/bgp_mpath.h"
 
 extern struct in_addr router_id_zebra;
 
@@ -650,6 +651,149 @@ DEFUN (no_bgp_confederation_peers,
   return CMD_SUCCESS;
 }
 
+/* Maximum-paths configuration */
+DEFUN (bgp_maxpaths,
+       bgp_maxpaths_cmd,
+       "maximum-paths <1-255>",
+       "Forward packets over multiple paths\n"
+       "Number of paths\n")
+{
+  struct bgp *bgp;
+  u_int16_t maxpaths;
+  int ret;
+
+  bgp = vty->index;
+
+  VTY_GET_INTEGER_RANGE ("maximum-paths", maxpaths, argv[0], 1, 255);
+
+  ret = bgp_maximum_paths_set (bgp, bgp_node_afi (vty), bgp_node_safi(vty),
+			       BGP_PEER_EBGP, maxpaths);
+  if (ret < 0)
+    {
+      vty_out (vty,
+	       "%% Failed to set maximum-paths %u for afi %u, safi %u%s",
+	       maxpaths, bgp_node_afi (vty), bgp_node_safi(vty), VTY_NEWLINE);
+      return CMD_WARNING;
+    }
+
+  return CMD_SUCCESS;
+}
+
+DEFUN (bgp_maxpaths_ibgp,
+       bgp_maxpaths_ibgp_cmd,
+       "maximum-paths ibgp <1-255>",
+       "Forward packets over multiple paths\n"
+       "iBGP-multipath\n"
+       "Number of paths\n")
+{
+  struct bgp *bgp;
+  u_int16_t maxpaths;
+  int ret;
+
+  bgp = vty->index;
+
+  VTY_GET_INTEGER_RANGE ("maximum-paths", maxpaths, argv[0], 1, 255);
+
+  ret = bgp_maximum_paths_set (bgp, bgp_node_afi (vty), bgp_node_safi(vty),
+			       BGP_PEER_IBGP, maxpaths);
+  if (ret < 0)
+    {
+      vty_out (vty,
+	       "%% Failed to set maximum-paths ibgp %u for afi %u, safi %u%s",
+	       maxpaths, bgp_node_afi (vty), bgp_node_safi(vty), VTY_NEWLINE);
+      return CMD_WARNING;
+    }
+
+  return CMD_SUCCESS;
+}
+
+DEFUN (no_bgp_maxpaths,
+       no_bgp_maxpaths_cmd,
+       "no maximum-paths",
+       NO_STR
+       "Forward packets over multiple paths\n"
+       "Number of paths\n")
+{
+  struct bgp *bgp;
+  int ret;
+
+  bgp = vty->index;
+
+  ret = bgp_maximum_paths_unset (bgp, bgp_node_afi (vty), bgp_node_safi(vty),
+				 BGP_PEER_EBGP);
+  if (ret < 0)
+    {
+      vty_out (vty,
+	       "%% Failed to unset maximum-paths for afi %u, safi %u%s",
+	       bgp_node_afi (vty), bgp_node_safi(vty), VTY_NEWLINE);
+      return CMD_WARNING;
+    }
+
+  return CMD_SUCCESS;
+}
+
+ALIAS (no_bgp_maxpaths,
+       no_bgp_maxpaths_arg_cmd,
+       "no maximum-paths <1-255>",
+       NO_STR
+       "Forward packets over multiple paths\n"
+       "Number of paths\n")
+
+DEFUN (no_bgp_maxpaths_ibgp,
+       no_bgp_maxpaths_ibgp_cmd,
+       "no maximum-paths ibgp",
+       NO_STR
+       "Forward packets over multiple paths\n"
+       "iBGP-multipath\n"
+       "Number of paths\n")
+{
+  struct bgp *bgp;
+  int ret;
+
+  bgp = vty->index;
+
+  ret = bgp_maximum_paths_unset (bgp, bgp_node_afi (vty), bgp_node_safi(vty),
+				 BGP_PEER_IBGP);
+  if (ret < 0)
+    {
+      vty_out (vty,
+	       "%% Failed to unset maximum-paths ibgp for afi %u, safi %u%s",
+	       bgp_node_afi (vty), bgp_node_safi(vty), VTY_NEWLINE);
+      return CMD_WARNING;
+    }
+
+  return CMD_SUCCESS;
+}
+
+ALIAS (no_bgp_maxpaths_ibgp,
+       no_bgp_maxpaths_ibgp_arg_cmd,
+       "no maximum-paths ibgp <1-255>",
+       NO_STR
+       "Forward packets over multiple paths\n"
+       "iBGP-multipath\n"
+       "Number of paths\n")
+
+int
+bgp_config_write_maxpaths (struct vty *vty, struct bgp *bgp, afi_t afi,
+			   safi_t safi, int *write)
+{
+  if (bgp->maxpaths[afi][safi].maxpaths_ebgp != BGP_DEFAULT_MAXPATHS)
+    {
+      bgp_config_write_family_header (vty, afi, safi, write);
+      vty_out (vty, " maximum-paths %d%s",
+	       bgp->maxpaths[afi][safi].maxpaths_ebgp, VTY_NEWLINE);
+    }
+
+  if (bgp->maxpaths[afi][safi].maxpaths_ibgp != BGP_DEFAULT_MAXPATHS)
+    {
+      bgp_config_write_family_header (vty, afi, safi, write);
+      vty_out (vty, " maximum-paths ibgp %d%s",
+	       bgp->maxpaths[afi][safi].maxpaths_ibgp, VTY_NEWLINE);
+    }
+
+  return 0;
+}
+
 /* BGP timers.  */
 
 DEFUN (bgp_timers,
@@ -9062,6 +9206,20 @@ bgp_vty_init (void)
   install_element (BGP_NODE, &bgp_confederation_peers_cmd);
   install_element (BGP_NODE, &no_bgp_confederation_peers_cmd);
 
+  /* "maximum-paths" commands. */
+  install_element (BGP_NODE, &bgp_maxpaths_cmd);
+  install_element (BGP_NODE, &no_bgp_maxpaths_cmd);
+  install_element (BGP_NODE, &no_bgp_maxpaths_arg_cmd);
+  install_element (BGP_IPV4_NODE, &bgp_maxpaths_cmd);
+  install_element (BGP_IPV4_NODE, &no_bgp_maxpaths_cmd);
+  install_element (BGP_IPV4_NODE, &no_bgp_maxpaths_arg_cmd);
+  install_element (BGP_NODE, &bgp_maxpaths_ibgp_cmd);
+  install_element (BGP_NODE, &no_bgp_maxpaths_ibgp_cmd);
+  install_element (BGP_NODE, &no_bgp_maxpaths_ibgp_arg_cmd);
+  install_element (BGP_IPV4_NODE, &bgp_maxpaths_ibgp_cmd);
+  install_element (BGP_IPV4_NODE, &no_bgp_maxpaths_ibgp_cmd);
+  install_element (BGP_IPV4_NODE, &no_bgp_maxpaths_ibgp_arg_cmd);
+
   /* "timers bgp" commands. */
   install_element (BGP_NODE, &bgp_timers_cmd);
   install_element (BGP_NODE, &no_bgp_timers_cmd);