kernel-netlink: Add global option to set MTU on installed routes

diff --git a/conf/plugins/kernel-netlink.opt b/conf/plugins/kernel-netlink.opt
index a8e421b..86cd92b 100644 (file)
--- a/conf/plugins/kernel-netlink.opt
+++ b/conf/plugins/kernel-netlink.opt
@@ -7,6 +7,9 @@ charon.plugins.kernel-netlink.fwmark =
        inverts the meaning (i.e. the rule only applies to packets that don't match
        the mark).
 
+charon.plugins.kernel-netlink.mtu = 0
+       MTU to set on installed routes, 0 to disable.
+
 charon.plugins.kernel-netlink.roam_events = yes
        Whether to trigger roam events when interfaces, addresses or routes change.
 

diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
index 82b637d..1b9dd84 100644 (file)
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
@@ -478,6 +478,11 @@ struct private_kernel_netlink_net_t {
         * list with routing tables to be excluded from route lookup
         */
        linked_list_t *rt_exclude;
+
+       /**
+        * MTU to set on installed routes
+        */
+       u_int32_t mtu;
 };
 
 /**
@@ -2055,6 +2060,7 @@ static status_t manage_srcroute(private_kernel_netlink_net_t *this,
        netlink_buf_t request;
        struct nlmsghdr *hdr;
        struct rtmsg *msg;
+       struct rtattr *rta;
        int ifindex;
        chunk_t chunk;
 
@@ -2107,6 +2113,17 @@ static status_t manage_srcroute(private_kernel_netlink_net_t *this,
        chunk.len = sizeof(ifindex);
        netlink_add_attribute(hdr, RTA_OIF, chunk, sizeof(request));
 
+       if (this->mtu)
+       {
+               chunk = chunk_alloca(RTA_LENGTH(sizeof(struct rtattr) +
+                                                                               sizeof(u_int32_t)));
+               rta = (struct rtattr*)chunk.ptr;
+               rta->rta_type = RTAX_MTU;
+               rta->rta_len = chunk.len;
+               memcpy(RTA_DATA(rta), &this->mtu, sizeof(u_int32_t));
+               netlink_add_attribute(hdr, RTA_METRICS, chunk, sizeof(request));
+       }
+
        return this->socket->send_ack(this->socket, hdr);
 }
 
@@ -2466,6 +2483,8 @@ kernel_netlink_net_t *kernel_netlink_net_create()
                                                "%s.prefer_temporary_addrs", FALSE, lib->ns),
                .roam_events = lib->settings->get_bool(lib->settings,
                                                "%s.plugins.kernel-netlink.roam_events", TRUE, lib->ns),
+               .mtu = lib->settings->get_int(lib->settings,
+                                               "%s.plugins.kernel-netlink.mtu", 0, lib->ns),
        );
        timerclear(&this->last_route_reinstall);
        timerclear(&this->next_roam);