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_route_add (struct zapi_route *api)
  47 {
  48     unsigned char uchar_prefix[16];
  49
  50     switch (api->prefix.family) {
  51     case AF_INET:
  52         inaddr_to_uchar(uchar_prefix, &api->prefix.u.prefix4);
  53         debugf(BABEL_DEBUG_ROUTE, "Adding new ipv4 route coming from Zebra.");
  54         xroute_add_new_route(uchar_prefix, api->prefix.prefixlen + 96,
  55                              api->metric, api->nexthops[0].ifindex, 0, 1);
  56         break;
  57     case AF_INET6:
  58         in6addr_to_uchar(uchar_prefix, &api->prefix.u.prefix6);
  59         debugf(BABEL_DEBUG_ROUTE, "Adding new ipv6 route coming from Zebra.");
  60         xroute_add_new_route(uchar_prefix, api->prefix.prefixlen,
  61                              api->metric, api->nexthops[0].ifindex, 0, 1);
  62         break;
  63     }
  64
  65     return 0;
  66 }
  67
  68 /* Remove redistributed route from Babel table. */
  69 int
  70 babel_route_delete (struct zapi_route *api)
  71 {
  72     unsigned char uchar_prefix[16];
  73     struct xroute *xroute = NULL;
  74
  75     switch (api->prefix.family) {
  76     case AF_INET:
  77         inaddr_to_uchar(uchar_prefix, &api->prefix.u.prefix4);
  78         xroute = find_xroute(uchar_prefix, api->prefix.prefixlen + 96);
  79         if (xroute != NULL) {
  80             debugf(BABEL_DEBUG_ROUTE, "Removing ipv4 route (from zebra).");
  81             flush_xroute(xroute);
  82         }
  83         break;
  84     case AF_INET6:
  85         in6addr_to_uchar(uchar_prefix, &api->prefix.u.prefix6);
  86         xroute = find_xroute(uchar_prefix, api->prefix.prefixlen);
  87         if (xroute != NULL) {
  88             debugf(BABEL_DEBUG_ROUTE, "Removing ipv6 route (from zebra).");
  89             flush_xroute(xroute);
  90         }
  91         break;
  92     }
  93
  94     return 0;
  95 }
  96
  97 struct xroute *
  98 find_xroute(const unsigned char *prefix, unsigned char plen)
  99 {
 100     int i;
 101     for(i = 0; i < numxroutes; i++) {
 102         if(xroutes[i].plen == plen &&
 103            memcmp(xroutes[i].prefix, prefix, 16) == 0)
 104             return &xroutes[i];
 105     }
 106     return NULL;
 107 }
 108
 109 void
 110 flush_xroute(struct xroute *xroute)
 111 {
 112     int i;
 113
 114     i = xroute - xroutes;
 115     assert(i >= 0 && i < numxroutes);
 116
 117     if(i != numxroutes - 1)
 118         memcpy(xroutes + i, xroutes + numxroutes - 1, sizeof(struct xroute));
 119     numxroutes--;
 120     VALGRIND_MAKE_MEM_UNDEFINED(xroutes + numxroutes, sizeof(struct xroute));
 121
 122     if(numxroutes == 0) {
 123         free(xroutes);
 124         xroutes = NULL;
 125         maxxroutes = 0;
 126     } else if(maxxroutes > 8 && numxroutes < maxxroutes / 4) {
 127         struct xroute *new_xroutes;
 128         int n = maxxroutes / 2;
 129         new_xroutes = realloc(xroutes, n * sizeof(struct xroute));
 130         if(new_xroutes == NULL)
 131             return;
 132         xroutes = new_xroutes;
 133         maxxroutes = n;
 134     }
 135 }
 136
 137 static int
 138 add_xroute(unsigned char prefix[16], unsigned char plen,
 139            unsigned short metric, unsigned int ifindex, int proto)
 140 {
 141     struct xroute *xroute = find_xroute(prefix, plen);
 142     if(xroute) {
 143         if(xroute->metric <= metric)
 144             return 0;
 145         xroute->metric = metric;
 146         return 1;
 147     }
 148
 149     if(numxroutes >= maxxroutes) {
 150         struct xroute *new_xroutes;
 151         int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;
 152         new_xroutes = xroutes == NULL ?
 153             malloc(n * sizeof(struct xroute)) :
 154             realloc(xroutes, n * sizeof(struct xroute));
 155         if(new_xroutes == NULL)
 156             return -1;
 157         maxxroutes = n;
 158         xroutes = new_xroutes;
 159     }
 160
 161     memcpy(xroutes[numxroutes].prefix, prefix, 16);
 162     xroutes[numxroutes].plen = plen;
 163     xroutes[numxroutes].metric = metric;
 164     xroutes[numxroutes].ifindex = ifindex;
 165     xroutes[numxroutes].proto = proto;
 166     numxroutes++;
 167     return 1;
 168 }
 169
 170 /* Returns an overestimate of the number of xroutes. */
 171 int
 172 xroutes_estimate()
 173 {
 174     return numxroutes;
 175 }
 176
 177 struct xroute_stream {
 178     int index;
 179 };
 180
 181 struct
 182 xroute_stream *
 183 xroute_stream(void)
 184 {
 185     struct xroute_stream *stream = malloc(sizeof(struct xroute_stream));
 186     if(stream == NULL)
 187        return NULL;
 188
 189     stream->index = 0;
 190     return stream;
 191 }
 192
 193 struct xroute *
 194 xroute_stream_next(struct xroute_stream *stream)
 195 {
 196     if(stream->index < numxroutes)
 197         return &xroutes[stream->index++];
 198     else
 199         return NULL;
 200 }
 201
 202 void
 203 xroute_stream_done(struct xroute_stream *stream)
 204 {
 205     free(stream);
 206 }
 207
 208 /* add an xroute, verifying some conditions; return 0 if there is no changes */
 209 static int
 210 xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
 211                      unsigned short metric, unsigned int ifindex,
 212                      int proto, int send_updates)
 213 {
 214     int rc;
 215     if(martian_prefix(prefix, plen))
 216         return 0;
 217     metric = redistribute_filter(prefix, plen, ifindex, proto);
 218     if(metric < INFINITY) {
 219         rc = add_xroute(prefix, plen, metric, ifindex, proto);
 220         if(rc > 0) {
 221             struct babel_route *route;
 222             route = find_installed_route(prefix, plen);
 223             if(route)
 224                 uninstall_route(route);
 225             if(send_updates)
 226                 send_update(NULL, 0, prefix, plen);
 227             return 1;
 228         }
 229     }
 230     return 0;
 231 }