babeld/xroute.c

   1 /*
   2  *  This file is free software: you may copy, redistribute and/or modify it
   3  *  under the terms of the GNU General Public License as published by the
   4  *  Free Software Foundation, either version 2 of the License, or (at your
   5  *  option) any later version.
   6  *
   7  *  This file is distributed in the hope that it will be useful, but
   8  *  WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  10  *  General Public License for more details.
  11  *
  12  *  You should have received a copy of the GNU General Public License
  13  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  14  *
  15  * This file incorporates work covered by the following copyright and
  16  * permission notice:
  17  *
  18 Copyright (c) 2007, 2008 by Juliusz Chroboczek
  19 Copyright 2011 by Matthieu Boutier and Juliusz Chroboczek
  20
  21 Permission is hereby granted, free of charge, to any person obtaining a copy
  22 of this software and associated documentation files (the "Software"), to deal
  23 in the Software without restriction, including without limitation the rights
  24 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  25 copies of the Software, and to permit persons to whom the Software is
  26 furnished to do so, subject to the following conditions:
  27
  28 The above copyright notice and this permission notice shall be included in
  29 all copies or substantial portions of the Software.
  30
  31 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  32 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  33 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  34 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  35 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  36 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  37 THE SOFTWARE.
  38 */
  39
  40 #include <stdlib.h>
  41 #include <stdio.h>
  42 #include <string.h>
  43 #include <errno.h>
  44 #include <assert.h>
  45 #include <sys/time.h>
  46 #include <netinet/in.h>
  47
  48 #include <zebra.h>
  49 #include "if.h"
  50 #include "log.h"
  51
  52 #include "babeld.h"
  53 #include "kernel.h"
  54 #include "neighbour.h"
  55 #include "message.h"
  56 #include "route.h"
  57 #include "xroute.h"
  58 #include "util.h"
  59 #include "babel_interface.h"
  60
  61 struct xroute *xroutes;
  62 int numxroutes = 0;
  63 int maxxroutes = 0;
  64
  65 /* Add redistributed route to Babel table. */
  66 int
  67 babel_ipv4_route_add (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
  68                       unsigned int ifindex, struct in_addr *nexthop)
  69 {
  70     unsigned char uchar_prefix[16];
  71
  72     inaddr_to_uchar(uchar_prefix, &prefix->prefix);
  73     debugf(BABEL_DEBUG_ROUTE, "Adding new ipv4 route comming from Zebra.");
  74     xroute_add_new_route(uchar_prefix, prefix->prefixlen, api->metric, ifindex,
  75                          0, 1);
  76     return 0;
  77 }
  78
  79 /* Remove redistributed route from Babel table. */
  80 int
  81 babel_ipv4_route_delete (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
  82                          unsigned int ifindex)
  83 {
  84     unsigned char uchar_prefix[16];
  85     struct xroute *xroute = NULL;
  86
  87     inaddr_to_uchar(uchar_prefix, &prefix->prefix);
  88     xroute = find_xroute(uchar_prefix, prefix->prefixlen);
  89     if (xroute != NULL) {
  90         debugf(BABEL_DEBUG_ROUTE, "Removing ipv4 route (from zebra).");
  91         flush_xroute(xroute);
  92     }
  93     return 0;
  94 }
  95
  96 /* Add redistributed route to Babel table. */
  97 int
  98 babel_ipv6_route_add (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
  99                       unsigned int ifindex, struct in6_addr *nexthop)
 100 {
 101     unsigned char uchar_prefix[16];
 102
 103     in6addr_to_uchar(uchar_prefix, &prefix->prefix);
 104     debugf(BABEL_DEBUG_ROUTE, "Adding new route comming from Zebra.");
 105     xroute_add_new_route(uchar_prefix, prefix->prefixlen, api->metric, ifindex,
 106                          0, 1);
 107     return 0;
 108 }
 109
 110 /* Remove redistributed route from Babel table. */
 111 int
 112 babel_ipv6_route_delete (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
 113                          unsigned int ifindex)
 114 {
 115     unsigned char uchar_prefix[16];
 116     struct xroute *xroute = NULL;
 117
 118     in6addr_to_uchar(uchar_prefix, &prefix->prefix);
 119     xroute = find_xroute(uchar_prefix, prefix->prefixlen);
 120     if (xroute != NULL) {
 121         debugf(BABEL_DEBUG_ROUTE, "Removing route (from zebra).");
 122         flush_xroute(xroute);
 123     }
 124     return 0;
 125 }
 126
 127 struct xroute *
 128 find_xroute(const unsigned char *prefix, unsigned char plen)
 129 {
 130     int i;
 131     for(i = 0; i < numxroutes; i++) {
 132         if(xroutes[i].plen == plen &&
 133            memcmp(xroutes[i].prefix, prefix, 16) == 0)
 134             return &xroutes[i];
 135     }
 136     return NULL;
 137 }
 138
 139 void
 140 flush_xroute(struct xroute *xroute)
 141 {
 142     int i;
 143
 144     i = xroute - xroutes;
 145     assert(i >= 0 && i < numxroutes);
 146
 147     if(i != numxroutes - 1)
 148         memcpy(xroutes + i, xroutes + numxroutes - 1, sizeof(struct xroute));
 149     numxroutes--;
 150     VALGRIND_MAKE_MEM_UNDEFINED(xroutes + numxroutes, sizeof(struct xroute));
 151
 152     if(numxroutes == 0) {
 153         free(xroutes);
 154         xroutes = NULL;
 155         maxxroutes = 0;
 156     } else if(maxxroutes > 8 && numxroutes < maxxroutes / 4) {
 157         struct xroute *new_xroutes;
 158         int n = maxxroutes / 2;
 159         new_xroutes = realloc(xroutes, n * sizeof(struct xroute));
 160         if(new_xroutes == NULL)
 161             return;
 162         xroutes = new_xroutes;
 163         maxxroutes = n;
 164     }
 165 }
 166
 167 static int
 168 add_xroute(unsigned char prefix[16], unsigned char plen,
 169            unsigned short metric, unsigned int ifindex, int proto)
 170 {
 171     struct xroute *xroute = find_xroute(prefix, plen);
 172     if(xroute) {
 173         if(xroute->metric <= metric)
 174             return 0;
 175         xroute->metric = metric;
 176         return 1;
 177     }
 178
 179     if(numxroutes >= maxxroutes) {
 180         struct xroute *new_xroutes;
 181         int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;
 182         new_xroutes = xroutes == NULL ?
 183             malloc(n * sizeof(struct xroute)) :
 184             realloc(xroutes, n * sizeof(struct xroute));
 185         if(new_xroutes == NULL)
 186             return -1;
 187         maxxroutes = n;
 188         xroutes = new_xroutes;
 189     }
 190
 191     memcpy(xroutes[numxroutes].prefix, prefix, 16);
 192     xroutes[numxroutes].plen = plen;
 193     xroutes[numxroutes].metric = metric;
 194     xroutes[numxroutes].ifindex = ifindex;
 195     xroutes[numxroutes].proto = proto;
 196     numxroutes++;
 197     return 1;
 198 }
 199
 200 /* add an xroute, verifying some conditions; return 0 if there is no changes */
 201 int
 202 xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
 203                      unsigned short metric, unsigned int ifindex,
 204                      int proto, int send_updates)
 205 {
 206     int rc;
 207     if(martian_prefix(prefix, plen))
 208         return 0;
 209     metric = redistribute_filter(prefix, plen, ifindex, proto);
 210     if(metric < INFINITY) {
 211         rc = add_xroute(prefix, plen, metric, ifindex, proto);
 212         if(rc > 0) {
 213             struct route *route;
 214             route = find_installed_route(prefix, plen);
 215             if(route) {
 216                 if(allow_duplicates < 0 ||
 217                    metric < allow_duplicates)
 218                     uninstall_route(route);
 219             }
 220             if(send_updates)
 221                 send_update(NULL, 0, prefix, plen);
 222             return 1;
 223         }
 224     }
 225     return 0;
 226 }