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 enum zebra_dplane_result 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, ZEBRA_DPLANE_INSTALL_FAILURE);
  38                 return ZEBRA_DPLANE_REQUEST_FAILURE;
  39         }
  40
  41         ret = netlink_mpls_multipath(RTM_NEWROUTE, lsp);
  42
  43         kernel_lsp_pass_fail(lsp,
  44                              (!ret) ? ZEBRA_DPLANE_INSTALL_SUCCESS
  45                                     : ZEBRA_DPLANE_INSTALL_FAILURE);
  46
  47         return ZEBRA_DPLANE_REQUEST_SUCCESS;
  48 }
  49
  50 /*
  51  * Update Label Forwarding entry in the kernel. This means that the Label
  52  * forwarding entry is already installed and needs an update - either a new
  53  * path is to be added, an installed path has changed (e.g., outgoing label)
  54  * or an installed path (but not all paths) has to be removed.
  55  * TODO: Performs a DEL followed by ADD now, need to change to REPLACE. Note
  56  * that REPLACE was originally implemented for IPv4 nexthops but removed as
  57  * it was not functioning when moving from swap to PHP as that was signaled
  58  * through the metric field (before kernel-MPLS). This shouldn't be an issue
  59  * any longer, so REPLACE can be reintroduced.
  60  */
  61 enum zebra_dplane_result kernel_upd_lsp(zebra_lsp_t *lsp)
  62 {
  63         int ret;
  64
  65         if (!lsp || !lsp->best_nhlfe) { // unexpected
  66                 kernel_lsp_pass_fail(lsp, ZEBRA_DPLANE_INSTALL_FAILURE);
  67                 return ZEBRA_DPLANE_REQUEST_FAILURE;
  68         }
  69
  70         ret = netlink_mpls_multipath(RTM_NEWROUTE, lsp);
  71
  72         kernel_lsp_pass_fail(lsp,
  73                              (!ret) ? ZEBRA_DPLANE_INSTALL_SUCCESS
  74                                     : ZEBRA_DPLANE_INSTALL_FAILURE);
  75
  76         return ZEBRA_DPLANE_REQUEST_SUCCESS;
  77 }
  78
  79 /*
  80  * Delete Label Forwarding entry from the kernel.
  81  */
  82 enum zebra_dplane_result kernel_del_lsp(zebra_lsp_t *lsp)
  83 {
  84         int ret;
  85
  86         if (!lsp) { // unexpected
  87                 kernel_lsp_pass_fail(lsp, ZEBRA_DPLANE_DELETE_FAILURE);
  88                 return ZEBRA_DPLANE_REQUEST_FAILURE;
  89         }
  90
  91         if (!CHECK_FLAG(lsp->flags, LSP_FLAG_INSTALLED)) {
  92                 kernel_lsp_pass_fail(lsp, ZEBRA_DPLANE_DELETE_FAILURE);
  93                 return ZEBRA_DPLANE_REQUEST_FAILURE;
  94         }
  95
  96         ret = netlink_mpls_multipath(RTM_DELROUTE, lsp);
  97
  98         kernel_lsp_pass_fail(lsp,
  99                              (!ret) ? ZEBRA_DPLANE_DELETE_SUCCESS
 100                                     : ZEBRA_DPLANE_DELETE_FAILURE);
 101
 102         return ZEBRA_DPLANE_REQUEST_SUCCESS;
 103 }
 104
 105 int mpls_kernel_init(void)
 106 {
 107         struct stat st;
 108
 109         /*
 110          * Check if the MPLS module is loaded in the kernel.
 111          */
 112         if (stat("/proc/sys/net/mpls", &st) != 0)
 113                 return -1;
 114
 115         return 0;
 116 };
 117
 118 #endif /* HAVE_NETLINK */