Basic kernel routing table syncing implemented. Learning of routes installed

by other programs or the kernel itself is not supported yet, but it's not
needed for development of other protocols.

2 files changed, 91 insertions, 3 deletions

diff --git a/sysdep/unix/krt-set.c b/sysdep/unix/krt-set.c
index 9da836d8..2c355eee 100644
--- a/sysdep/unix/krt-set.c
+++ b/sysdep/unix/krt-set.c
@@ -10,7 +10,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <sys/ioctl.h>
-#include <errno.h>
+#include <net/route.h>
 
 #define LOCAL_DEBUG
 
@@ -18,18 +18,102 @@
 #include "nest/iface.h"
 #include "nest/route.h"
 #include "nest/protocol.h"
-#include "lib/timer.h"
 #include "lib/unix.h"
 #include "lib/krt.h"
 
+int
+krt_capable(net *net, rte *e)
+{
+  rta *a = e->attrs;
+
+  return
+    a->cast == RTC_UNICAST &&
+    (a->dest == RTD_ROUTER
+#ifndef CONFIG_AUTO_ROUTES
+     || a->dest == RTD_DEVICE
+#endif
+#ifdef RTF_REJECT
+     || a->dest == RTD_UNREACHABLE
+#endif
+     ) &&
+    !a->tos;
+}
+
+void
+krt_remove_route(net *net, rte *old)
+{
+  struct rtentry re;
+
+  if (old && !krt_capable(net, old))
+    {
+      DBG("krt_remove_route(ignored %I/%d)\n", net->n.prefix, net->n.pxlen);
+      return;
+    }
+  DBG("krt_remove_route(%I/%d)\n", net->n.prefix, net->n.pxlen);
+  bzero(&re, sizeof(re));
+  fill_in_sockaddr((struct sockaddr_in *) &re.rt_dst, net->n.prefix, 0);
+  fill_in_sockaddr((struct sockaddr_in *) &re.rt_genmask, ipa_mkmask(net->n.pxlen), 0);
+  if (ioctl(if_scan_sock, SIOCDELRT, &re) < 0)
+    log(L_ERR "SIOCDELRT(%I/%d): %m", net->n.prefix, net->n.pxlen);
+}
+
+void
+krt_add_route(net *net, rte *new)
+{
+  struct rtentry re;
+  rta *a = new->attrs;
+
+  if (!krt_capable(net, new))
+    {
+      DBG("krt_add_route(ignored %I/%d)\n", net->n.prefix, net->n.pxlen);
+      return;
+    }
+  DBG("krt_add_route(%I/%d)\n", net->n.prefix, net->n.pxlen);
+  bzero(&re, sizeof(re));
+  fill_in_sockaddr((struct sockaddr_in *) &re.rt_dst, net->n.prefix, 0);
+  fill_in_sockaddr((struct sockaddr_in *) &re.rt_genmask, ipa_mkmask(net->n.pxlen), 0);
+  re.rt_flags = RTF_UP;
+  if (net->n.pxlen == 32)
+    re.rt_flags |= RTF_HOST;
+  switch (a->dest)
+    {
+    case RTD_ROUTER:
+      fill_in_sockaddr((struct sockaddr_in *) &re.rt_gateway, a->gw, 0);
+      re.rt_flags |= RTF_GATEWAY;
+      break;
+#ifndef CONFIG_AUTO_ROUTES
+    case RTD_DEVICE:
+      re.rt_dev = a->iface->name;
+      break;
+#endif
+#ifdef RTF_REJECT
+    case RTD_UNREACHABLE:
+      re.rt_flags |= RTF_REJECT;
+      break;
+#endif
+    default:
+      die("krt set: unknown flags, but not filtered");
+    }
+
+  if (ioctl(if_scan_sock, SIOCADDRT, &re) < 0)
+    log(L_ERR "SIOCADDRT(%I/%d): %m", net->n.prefix, net->n.pxlen);
+}
+
 void
 krt_set_notify(struct proto *x, net *net, rte *new, rte *old)
 {
-  DBG("krt_set_notify(%I/%d)\n", net->n.prefix, net->n.pxlen);
+  if (x->state != PRS_UP)
+    return;
+  if (old)
+    krt_remove_route(net, old);
+  if (new)
+    krt_add_route(net, new);
 }
 
 void
 krt_set_preconfig(struct krt_proto *x)
 {
+  if (if_scan_sock < 0)
+    die("krt set: missing socket");
   x->p.rt_notify = krt_set_notify;
 }
diff --git a/sysdep/unix/krt-set.h b/sysdep/unix/krt-set.h
index 3b906baf..a2107e12 100644
--- a/sysdep/unix/krt-set.h
+++ b/sysdep/unix/krt-set.h
@@ -12,4 +12,8 @@
 struct krt_set_params {
 };
 
+void krt_remove_route(net *net, rte *old);
+void krt_add_route(net *net, rte *new);
+int krt_capable(net *net, rte *e);
+
 #endif