zebra/zebra_mpls_netlink.c

   1 /* MPLS forwarding table updates using netlink over GNU/Linux system.
   2  * Copyright (C) 2016  Cumulus Networks, Inc.
   3  *
   4  * This file is part of Quagga.
   5  *
   6  * Quagga is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * Quagga is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22
  23 #ifdef HAVE_NETLINK
  24
  25 #include "zebra/rt.h"
  26 #include "zebra/rt_netlink.h"
  27 #include "zebra/zebra_mpls.h"
  28
  29 /*
  30  * Install Label Forwarding entry into the kernel.
  31  */
  32 void kernel_add_lsp(zebra_lsp_t *lsp)
  33 {
  34         int ret;
  35
  36         if (!lsp || !lsp->best_nhlfe) { // unexpected
  37                 kernel_lsp_pass_fail(lsp, SOUTHBOUND_INSTALL_FAILURE);
  38                 return;
  39         }
  40
  41         ret = netlink_mpls_multipath(RTM_NEWROUTE, lsp);
  42
  43         kernel_lsp_pass_fail(lsp,
  44                              (!ret) ? SOUTHBOUND_INSTALL_SUCCESS
  45                                     : SOUTHBOUND_INSTALL_FAILURE);
  46 }
  47
  48 /*
  49  * Update Label Forwarding entry in the kernel. This means that the Label
  50  * forwarding entry is already installed and needs an update - either a new
  51  * path is to be added, an installed path has changed (e.g., outgoing label)
  52  * or an installed path (but not all paths) has to be removed.
  53  * TODO: Performs a DEL followed by ADD now, need to change to REPLACE. Note
  54  * that REPLACE was originally implemented for IPv4 nexthops but removed as
  55  * it was not functioning when moving from swap to PHP as that was signaled
  56  * through the metric field (before kernel-MPLS). This shouldn't be an issue
  57  * any longer, so REPLACE can be reintroduced.
  58  */
  59 void kernel_upd_lsp(zebra_lsp_t *lsp)
  60 {
  61         int ret;
  62
  63         if (!lsp || !lsp->best_nhlfe) { // unexpected
  64                 kernel_lsp_pass_fail(lsp, SOUTHBOUND_INSTALL_FAILURE);
  65                 return;
  66         }
  67
  68         ret = netlink_mpls_multipath(RTM_NEWROUTE, lsp);
  69
  70         kernel_lsp_pass_fail(lsp,
  71                              (!ret) ? SOUTHBOUND_INSTALL_SUCCESS
  72                                     : SOUTHBOUND_INSTALL_FAILURE);
  73 }
  74
  75 /*
  76  * Delete Label Forwarding entry from the kernel.
  77  */
  78 void kernel_del_lsp(zebra_lsp_t *lsp)
  79 {
  80         int ret;
  81
  82         if (!lsp) { // unexpected
  83                 kernel_lsp_pass_fail(lsp, SOUTHBOUND_DELETE_FAILURE);
  84                 return;
  85         }
  86
  87         if (!CHECK_FLAG(lsp->flags, LSP_FLAG_INSTALLED)) {
  88                 kernel_lsp_pass_fail(lsp, SOUTHBOUND_DELETE_FAILURE);
  89                 return;
  90         }
  91
  92         ret = netlink_mpls_multipath(RTM_DELROUTE, lsp);
  93
  94         kernel_lsp_pass_fail(lsp,
  95                              (!ret) ? SOUTHBOUND_DELETE_SUCCESS
  96                                     : SOUTHBOUND_DELETE_FAILURE);
  97 }
  98
  99 int mpls_kernel_init(void)
 100 {
 101         struct stat st;
 102
 103         /*
 104          * Check if the MPLS module is loaded in the kernel.
 105          */
 106         if (stat("/proc/sys/net/mpls", &st) != 0)
 107                 return -1;
 108
 109         return 0;
 110 };
 111
 112 #endif /* HAVE_NETLINK */