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 <zebra.h>
  41 #include "if.h"
  42 #include "log.h"
  43
  44 #include "babeld.h"
  45 #include "kernel.h"
  46 #include "neighbour.h"
  47 #include "message.h"
  48 #include "route.h"
  49 #include "xroute.h"
  50 #include "util.h"
  51 #include "babel_interface.h"
  52
  53 static int xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
  54                                 unsigned short metric, unsigned int ifindex,
  55                                 int proto, int send_updates);
  56
  57 static struct xroute *xroutes;
  58 static int numxroutes = 0, maxxroutes = 0;
  59
  60 /* Add redistributed route to Babel table. */
  61 int
  62 babel_ipv4_route_add (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
  63                       unsigned int ifindex, struct in_addr *nexthop)
  64 {
  65     unsigned char uchar_prefix[16];
  66
  67     inaddr_to_uchar(uchar_prefix, &prefix->prefix);
  68     debugf(BABEL_DEBUG_ROUTE, "Adding new ipv4 route comming from Zebra.");
  69     xroute_add_new_route(uchar_prefix, prefix->prefixlen + 96,
  70                          api->metric, ifindex, 0, 1);
  71     return 0;
  72 }
  73
  74 /* Remove redistributed route from Babel table. */
  75 int
  76 babel_ipv4_route_delete (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
  77                          unsigned int ifindex)
  78 {
  79     unsigned char uchar_prefix[16];
  80     struct xroute *xroute = NULL;
  81
  82     inaddr_to_uchar(uchar_prefix, &prefix->prefix);
  83     xroute = find_xroute(uchar_prefix, prefix->prefixlen + 96);
  84     if (xroute != NULL) {
  85         debugf(BABEL_DEBUG_ROUTE, "Removing ipv4 route (from zebra).");
  86         flush_xroute(xroute);
  87     }
  88     return 0;
  89 }
  90
  91 /* Add redistributed route to Babel table. */
  92 int
  93 babel_ipv6_route_add (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
  94                       unsigned int ifindex, struct in6_addr *nexthop)
  95 {
  96     unsigned char uchar_prefix[16];
  97
  98     in6addr_to_uchar(uchar_prefix, &prefix->prefix);
  99     debugf(BABEL_DEBUG_ROUTE, "Adding new route comming from Zebra.");
 100     xroute_add_new_route(uchar_prefix, prefix->prefixlen, api->metric, ifindex,
 101                          0, 1);
 102     return 0;
 103 }
 104
 105 /* Remove redistributed route from Babel table. */
 106 int
 107 babel_ipv6_route_delete (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
 108                          unsigned int ifindex)
 109 {
 110     unsigned char uchar_prefix[16];
 111     struct xroute *xroute = NULL;
 112
 113     in6addr_to_uchar(uchar_prefix, &prefix->prefix);
 114     xroute = find_xroute(uchar_prefix, prefix->prefixlen);
 115     if (xroute != NULL) {
 116         debugf(BABEL_DEBUG_ROUTE, "Removing route (from zebra).");
 117         flush_xroute(xroute);
 118     }
 119     return 0;
 120 }
 121
 122 struct xroute *
 123 find_xroute(const unsigned char *prefix, unsigned char plen)
 124 {
 125     int i;
 126     for(i = 0; i < numxroutes; i++) {
 127         if(xroutes[i].plen == plen &&
 128            memcmp(xroutes[i].prefix, prefix, 16) == 0)
 129             return &xroutes[i];
 130     }
 131     return NULL;
 132 }
 133
 134 void
 135 flush_xroute(struct xroute *xroute)
 136 {
 137     int i;
 138
 139     i = xroute - xroutes;
 140     assert(i >= 0 && i < numxroutes);
 141
 142     if(i != numxroutes - 1)
 143         memcpy(xroutes + i, xroutes + numxroutes - 1, sizeof(struct xroute));
 144     numxroutes--;
 145     VALGRIND_MAKE_MEM_UNDEFINED(xroutes + numxroutes, sizeof(struct xroute));
 146
 147     if(numxroutes == 0) {
 148         free(xroutes);
 149         xroutes = NULL;
 150         maxxroutes = 0;
 151     } else if(maxxroutes > 8 && numxroutes < maxxroutes / 4) {
 152         struct xroute *new_xroutes;
 153         int n = maxxroutes / 2;
 154         new_xroutes = realloc(xroutes, n * sizeof(struct xroute));
 155         if(new_xroutes == NULL)
 156             return;
 157         xroutes = new_xroutes;
 158         maxxroutes = n;
 159     }
 160 }
 161
 162 static int
 163 add_xroute(unsigned char prefix[16], unsigned char plen,
 164            unsigned short metric, unsigned int ifindex, int proto)
 165 {
 166     struct xroute *xroute = find_xroute(prefix, plen);
 167     if(xroute) {
 168         if(xroute->metric <= metric)
 169             return 0;
 170         xroute->metric = metric;
 171         return 1;
 172     }
 173
 174     if(numxroutes >= maxxroutes) {
 175         struct xroute *new_xroutes;
 176         int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;
 177         new_xroutes = xroutes == NULL ?
 178             malloc(n * sizeof(struct xroute)) :
 179             realloc(xroutes, n * sizeof(struct xroute));
 180         if(new_xroutes == NULL)
 181             return -1;
 182         maxxroutes = n;
 183         xroutes = new_xroutes;
 184     }
 185
 186     memcpy(xroutes[numxroutes].prefix, prefix, 16);
 187     xroutes[numxroutes].plen = plen;
 188     xroutes[numxroutes].metric = metric;
 189     xroutes[numxroutes].ifindex = ifindex;
 190     xroutes[numxroutes].proto = proto;
 191     numxroutes++;
 192     return 1;
 193 }
 194
 195 /* Returns an overestimate of the number of xroutes. */
 196 int
 197 xroutes_estimate()
 198 {
 199     return numxroutes;
 200 }
 201
 202 void
 203 for_all_xroutes(void (*f)(struct xroute*, void*), void *closure)
 204 {
 205     int i;
 206
 207     for(i = 0; i < numxroutes; i++)
 208         (*f)(&xroutes[i], closure);
 209 }
 210
 211 /* add an xroute, verifying some conditions; return 0 if there is no changes */
 212 static int
 213 xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
 214                      unsigned short metric, unsigned int ifindex,
 215                      int proto, int send_updates)
 216 {
 217     int rc;
 218     if(martian_prefix(prefix, plen))
 219         return 0;
 220     metric = redistribute_filter(prefix, plen, ifindex, proto);
 221     if(metric < INFINITY) {
 222         rc = add_xroute(prefix, plen, metric, ifindex, proto);
 223         if(rc > 0) {
 224             struct babel_route *route;
 225             route = find_installed_route(prefix, plen);
 226             if(route) {
 227                 if(allow_duplicates < 0 ||
 228                    metric < allow_duplicates)
 229                     uninstall_route(route);
 230             }
 231             if(send_updates)
 232                 send_update(NULL, 0, prefix, plen);
 233             return 1;
 234         }
 235     }
 236     return 0;
 237 }