babeld/xroute.c

   1 /*
   2 Copyright (c) 2007, 2008 by Juliusz Chroboczek
   3 Copyright 2011 by Matthieu Boutier and Juliusz Chroboczek
   4
   5 Permission is hereby granted, free of charge, to any person obtaining a copy
   6 of this software and associated documentation files (the "Software"), to deal
   7 in the Software without restriction, including without limitation the rights
   8 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9 copies of the Software, and to permit persons to whom the Software is
  10 furnished to do so, subject to the following conditions:
  11
  12 The above copyright notice and this permission notice shall be included in
  13 all copies or substantial portions of the Software.
  14
  15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  18 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21 THE SOFTWARE.
  22 */
  23
  24 #include <zebra.h>
  25 #include "if.h"
  26 #include "log.h"
  27
  28 #include "babeld.h"
  29 #include "kernel.h"
  30 #include "neighbour.h"
  31 #include "message.h"
  32 #include "route.h"
  33 #include "xroute.h"
  34 #include "util.h"
  35 #include "babel_interface.h"
  36
  37 static int xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
  38                                 unsigned short metric, unsigned int ifindex,
  39                                 int proto, int send_updates);
  40
  41 static struct xroute *xroutes;
  42 static int numxroutes = 0, maxxroutes = 0;
  43
  44 /* Add redistributed route to Babel table. */
  45 int
  46 babel_ipv4_route_add (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
  47                       unsigned int ifindex, struct in_addr *nexthop)
  48 {
  49     unsigned char uchar_prefix[16];
  50
  51     inaddr_to_uchar(uchar_prefix, &prefix->prefix);
  52     debugf(BABEL_DEBUG_ROUTE, "Adding new ipv4 route coming from Zebra.");
  53     xroute_add_new_route(uchar_prefix, prefix->prefixlen + 96,
  54                          api->metric, ifindex, 0, 1);
  55     return 0;
  56 }
  57
  58 /* Remove redistributed route from Babel table. */
  59 int
  60 babel_ipv4_route_delete (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
  61                          unsigned int ifindex)
  62 {
  63     unsigned char uchar_prefix[16];
  64     struct xroute *xroute = NULL;
  65
  66     inaddr_to_uchar(uchar_prefix, &prefix->prefix);
  67     xroute = find_xroute(uchar_prefix, prefix->prefixlen + 96);
  68     if (xroute != NULL) {
  69         debugf(BABEL_DEBUG_ROUTE, "Removing ipv4 route (from zebra).");
  70         flush_xroute(xroute);
  71     }
  72     return 0;
  73 }
  74
  75 /* Add redistributed route to Babel table. */
  76 int
  77 babel_ipv6_route_add (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
  78                       unsigned int ifindex, struct in6_addr *nexthop)
  79 {
  80     unsigned char uchar_prefix[16];
  81
  82     in6addr_to_uchar(uchar_prefix, &prefix->prefix);
  83     debugf(BABEL_DEBUG_ROUTE, "Adding new route coming from Zebra.");
  84     xroute_add_new_route(uchar_prefix, prefix->prefixlen, api->metric, ifindex,
  85                          0, 1);
  86     return 0;
  87 }
  88
  89 /* Remove redistributed route from Babel table. */
  90 int
  91 babel_ipv6_route_delete (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
  92                          unsigned int ifindex)
  93 {
  94     unsigned char uchar_prefix[16];
  95     struct xroute *xroute = NULL;
  96
  97     in6addr_to_uchar(uchar_prefix, &prefix->prefix);
  98     xroute = find_xroute(uchar_prefix, prefix->prefixlen);
  99     if (xroute != NULL) {
 100         debugf(BABEL_DEBUG_ROUTE, "Removing route (from zebra).");
 101         flush_xroute(xroute);
 102     }
 103     return 0;
 104 }
 105
 106 struct xroute *
 107 find_xroute(const unsigned char *prefix, unsigned char plen)
 108 {
 109     int i;
 110     for(i = 0; i < numxroutes; i++) {
 111         if(xroutes[i].plen == plen &&
 112            memcmp(xroutes[i].prefix, prefix, 16) == 0)
 113             return &xroutes[i];
 114     }
 115     return NULL;
 116 }
 117
 118 void
 119 flush_xroute(struct xroute *xroute)
 120 {
 121     int i;
 122
 123     i = xroute - xroutes;
 124     assert(i >= 0 && i < numxroutes);
 125
 126     if(i != numxroutes - 1)
 127         memcpy(xroutes + i, xroutes + numxroutes - 1, sizeof(struct xroute));
 128     numxroutes--;
 129     VALGRIND_MAKE_MEM_UNDEFINED(xroutes + numxroutes, sizeof(struct xroute));
 130
 131     if(numxroutes == 0) {
 132         free(xroutes);
 133         xroutes = NULL;
 134         maxxroutes = 0;
 135     } else if(maxxroutes > 8 && numxroutes < maxxroutes / 4) {
 136         struct xroute *new_xroutes;
 137         int n = maxxroutes / 2;
 138         new_xroutes = realloc(xroutes, n * sizeof(struct xroute));
 139         if(new_xroutes == NULL)
 140             return;
 141         xroutes = new_xroutes;
 142         maxxroutes = n;
 143     }
 144 }
 145
 146 static int
 147 add_xroute(unsigned char prefix[16], unsigned char plen,
 148            unsigned short metric, unsigned int ifindex, int proto)
 149 {
 150     struct xroute *xroute = find_xroute(prefix, plen);
 151     if(xroute) {
 152         if(xroute->metric <= metric)
 153             return 0;
 154         xroute->metric = metric;
 155         return 1;
 156     }
 157
 158     if(numxroutes >= maxxroutes) {
 159         struct xroute *new_xroutes;
 160         int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;
 161         new_xroutes = xroutes == NULL ?
 162             malloc(n * sizeof(struct xroute)) :
 163             realloc(xroutes, n * sizeof(struct xroute));
 164         if(new_xroutes == NULL)
 165             return -1;
 166         maxxroutes = n;
 167         xroutes = new_xroutes;
 168     }
 169
 170     memcpy(xroutes[numxroutes].prefix, prefix, 16);
 171     xroutes[numxroutes].plen = plen;
 172     xroutes[numxroutes].metric = metric;
 173     xroutes[numxroutes].ifindex = ifindex;
 174     xroutes[numxroutes].proto = proto;
 175     numxroutes++;
 176     return 1;
 177 }
 178
 179 /* Returns an overestimate of the number of xroutes. */
 180 int
 181 xroutes_estimate()
 182 {
 183     return numxroutes;
 184 }
 185
 186 struct xroute_stream {
 187     int index;
 188 };
 189
 190 struct
 191 xroute_stream *
 192 xroute_stream(void)
 193 {
 194     struct xroute_stream *stream = malloc(sizeof(struct xroute_stream));
 195     if(stream == NULL)
 196        return NULL;
 197
 198     stream->index = 0;
 199     return stream;
 200 }
 201
 202 struct xroute *
 203 xroute_stream_next(struct xroute_stream *stream)
 204 {
 205     if(stream->index < numxroutes)
 206         return &xroutes[stream->index++];
 207     else
 208         return NULL;
 209 }
 210
 211 void
 212 xroute_stream_done(struct xroute_stream *stream)
 213 {
 214     free(stream);
 215 }
 216
 217 /* add an xroute, verifying some conditions; return 0 if there is no changes */
 218 static int
 219 xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
 220                      unsigned short metric, unsigned int ifindex,
 221                      int proto, int send_updates)
 222 {
 223     int rc;
 224     if(martian_prefix(prefix, plen))
 225         return 0;
 226     metric = redistribute_filter(prefix, plen, ifindex, proto);
 227     if(metric < INFINITY) {
 228         rc = add_xroute(prefix, plen, metric, ifindex, proto);
 229         if(rc > 0) {
 230             struct babel_route *route;
 231             route = find_installed_route(prefix, plen);
 232             if(route)
 233                 uninstall_route(route);
 234             if(send_updates)
 235                 send_update(NULL, 0, prefix, plen);
 236             return 1;
 237         }
 238     }
 239     return 0;
 240 }