babeld: Initial import, for Babel routing protocol.

* Initial import of the Babel routing protocol, ported to Quagga.
* LICENCE: Update the original LICENCE file to include all known potentially
  applicable copyright claims.  Ask that any future contributors to babeld/
  grant MIT/X11 licence to their work.
* *.{c,h}: Add GPL headers, in according with the SFLC guidance on
  dealing with potentially mixed GPL/other licensed work, at:

  https://www.softwarefreedom.org/resources/2007/gpl-non-gpl-collaboration.html

1 files changed, 226 insertions, 0 deletions

diff --git a/babeld/xroute.c b/babeld/xroute.c
new file mode 100644
index 00000000..42f83d07
--- /dev/null
+++ b/babeld/xroute.c
@@ -0,0 +1,226 @@
+/*  
+ *  This file is free software: you may copy, redistribute and/or modify it  
+ *  under the terms of the GNU General Public License as published by the  
+ *  Free Software Foundation, either version 2 of the License, or (at your  
+ *  option) any later version.  
+ *  
+ *  This file is distributed in the hope that it will be useful, but  
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of  
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  
+ *  General Public License for more details.  
+ *  
+ *  You should have received a copy of the GNU General Public License  
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  
+ *  
+ * This file incorporates work covered by the following copyright and  
+ * permission notice:  
+ *  
+Copyright (c) 2007, 2008 by Juliusz Chroboczek
+Copyright 2011 by Matthieu Boutier and Juliusz Chroboczek
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+
+#include <zebra.h>
+#include "if.h"
+#include "log.h"
+
+#include "babeld.h"
+#include "kernel.h"
+#include "neighbour.h"
+#include "message.h"
+#include "route.h"
+#include "xroute.h"
+#include "util.h"
+#include "babel_interface.h"
+
+struct xroute *xroutes;
+int numxroutes = 0;
+int maxxroutes = 0;
+
+/* Add redistributed route to Babel table. */
+int
+babel_ipv4_route_add (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
+                      unsigned int ifindex, struct in_addr *nexthop)
+{
+    unsigned char uchar_prefix[16];
+
+    inaddr_to_uchar(uchar_prefix, &prefix->prefix);
+    debugf(BABEL_DEBUG_ROUTE, "Adding new ipv4 route comming from Zebra.");
+    xroute_add_new_route(uchar_prefix, prefix->prefixlen, api->metric, ifindex,
+                         0, 1);
+    return 0;
+}
+
+/* Remove redistributed route from Babel table. */
+int
+babel_ipv4_route_delete (struct zapi_ipv4 *api, struct prefix_ipv4 *prefix,
+                         unsigned int ifindex)
+{
+    unsigned char uchar_prefix[16];
+    struct xroute *xroute = NULL;
+
+    inaddr_to_uchar(uchar_prefix, &prefix->prefix);
+    xroute = find_xroute(uchar_prefix, prefix->prefixlen);
+    if (xroute != NULL) {
+        debugf(BABEL_DEBUG_ROUTE, "Removing ipv4 route (from zebra).");
+        flush_xroute(xroute);
+    }
+    return 0;
+}
+
+/* Add redistributed route to Babel table. */
+int
+babel_ipv6_route_add (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
+                      unsigned int ifindex, struct in6_addr *nexthop)
+{
+    unsigned char uchar_prefix[16];
+
+    in6addr_to_uchar(uchar_prefix, &prefix->prefix);
+    debugf(BABEL_DEBUG_ROUTE, "Adding new route comming from Zebra.");
+    xroute_add_new_route(uchar_prefix, prefix->prefixlen, api->metric, ifindex,
+                         0, 1);
+    return 0;
+}
+
+/* Remove redistributed route from Babel table. */
+int
+babel_ipv6_route_delete (struct zapi_ipv6 *api, struct prefix_ipv6 *prefix,
+                         unsigned int ifindex)
+{
+    unsigned char uchar_prefix[16];
+    struct xroute *xroute = NULL;
+
+    in6addr_to_uchar(uchar_prefix, &prefix->prefix);
+    xroute = find_xroute(uchar_prefix, prefix->prefixlen);
+    if (xroute != NULL) {
+        debugf(BABEL_DEBUG_ROUTE, "Removing route (from zebra).");
+        flush_xroute(xroute);
+    }
+    return 0;
+}
+
+struct xroute *
+find_xroute(const unsigned char *prefix, unsigned char plen)
+{
+    int i;
+    for(i = 0; i < numxroutes; i++) {
+        if(xroutes[i].plen == plen &&
+           memcmp(xroutes[i].prefix, prefix, 16) == 0)
+            return &xroutes[i];
+    }
+    return NULL;
+}
+
+void
+flush_xroute(struct xroute *xroute)
+{
+    int i;
+
+    i = xroute - xroutes;
+    assert(i >= 0 && i < numxroutes);
+
+    if(i != numxroutes - 1)
+        memcpy(xroutes + i, xroutes + numxroutes - 1, sizeof(struct xroute));
+    numxroutes--;
+    VALGRIND_MAKE_MEM_UNDEFINED(xroutes + numxroutes, sizeof(struct xroute));
+
+    if(numxroutes == 0) {
+        free(xroutes);
+        xroutes = NULL;
+        maxxroutes = 0;
+    } else if(maxxroutes > 8 && numxroutes < maxxroutes / 4) {
+        struct xroute *new_xroutes;
+        int n = maxxroutes / 2;
+        new_xroutes = realloc(xroutes, n * sizeof(struct xroute));
+        if(new_xroutes == NULL)
+            return;
+        xroutes = new_xroutes;
+        maxxroutes = n;
+    }
+}
+
+static int
+add_xroute(unsigned char prefix[16], unsigned char plen,
+           unsigned short metric, unsigned int ifindex, int proto)
+{
+    struct xroute *xroute = find_xroute(prefix, plen);
+    if(xroute) {
+        if(xroute->metric <= metric)
+            return 0;
+        xroute->metric = metric;
+        return 1;
+    }
+
+    if(numxroutes >= maxxroutes) {
+        struct xroute *new_xroutes;
+        int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;
+        new_xroutes = xroutes == NULL ?
+            malloc(n * sizeof(struct xroute)) :
+            realloc(xroutes, n * sizeof(struct xroute));
+        if(new_xroutes == NULL)
+            return -1;
+        maxxroutes = n;
+        xroutes = new_xroutes;
+    }
+
+    memcpy(xroutes[numxroutes].prefix, prefix, 16);
+    xroutes[numxroutes].plen = plen;
+    xroutes[numxroutes].metric = metric;
+    xroutes[numxroutes].ifindex = ifindex;
+    xroutes[numxroutes].proto = proto;
+    numxroutes++;
+    return 1;
+}
+
+/* add an xroute, verifying some conditions; return 0 if there is no changes */
+int
+xroute_add_new_route(unsigned char prefix[16], unsigned char plen,
+                     unsigned short metric, unsigned int ifindex,
+                     int proto, int send_updates)
+{
+    int rc;
+    if(martian_prefix(prefix, plen))
+        return 0;
+    metric = redistribute_filter(prefix, plen, ifindex, proto);
+    if(metric < INFINITY) {
+        rc = add_xroute(prefix, plen, metric, ifindex, proto);
+        if(rc > 0) {
+            struct route *route;
+            route = find_installed_route(prefix, plen);
+            if(route) {
+                if(allow_duplicates < 0 ||
+                   metric < allow_duplicates)
+                    uninstall_route(route);
+            }
+            if(send_updates)
+                send_update(NULL, 0, prefix, plen);
+            return 1;
+        }
+    }
+    return 0;
+}