zebra: add ZEBRA_IF_DUMMY flag for dummy interfaces

Introduce ZEBRA_IF_DUMMY interface flag to identify Linux dummy interfaces [0]. These interfaces behave similarly to loopback interfaces and can be specially handled by daemons. [0]: https://github.com/torvalds/linux/blob/master/drivers/net/dummy.c Signed-off-by: Gabriel Goller <[email protected]>
FRRouting · Feb 25, 2025 · 80e9671 · 80e9671
1 parent 3f290c9
commit 80e9671
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Showing 5 changed files with 19 additions and 1 deletion.
diff --git a/lib/if.h b/lib/if.h
@@ -242,6 +242,7 @@ struct interface {
 #define ZEBRA_INTERFACE_SUB        (1 << 1)
 #define ZEBRA_INTERFACE_LINKDETECTION (1 << 2)
 #define ZEBRA_INTERFACE_VRF_LOOPBACK (1 << 3)
+#define ZEBRA_INTERFACE_DUMMY (1 << 4)
 
 	/* Interface flags. */
 	uint64_t flags;

diff --git a/zebra/if_netlink.c b/zebra/if_netlink.c
@@ -221,6 +221,8 @@ static void netlink_determine_zebra_iftype(const char *kind,
 		*zif_type = ZEBRA_IF_BOND;
 	else if (strcmp(kind, "gre") == 0)
 		*zif_type = ZEBRA_IF_GRE;
+	else if (strcmp(kind, "dummy") == 0)
+		*zif_type = ZEBRA_IF_DUMMY;
 }
 
 static void netlink_vrf_change(struct nlmsghdr *h, struct rtattr *tb,
@@ -576,6 +578,7 @@ static void netlink_interface_update_l2info(struct zebra_dplane_ctx *ctx,
 	case ZEBRA_IF_MACVLAN:
 	case ZEBRA_IF_VETH:
 	case ZEBRA_IF_BOND:
+	case ZEBRA_IF_DUMMY:
 		break;
 	}
 }

diff --git a/zebra/interface.c b/zebra/interface.c
@@ -548,6 +548,9 @@ void if_add_update(struct interface *ifp)
 
 	zebra_interface_add_update(ifp);
 
+	if (IS_ZEBRA_IF_DUMMY(ifp))
+		SET_FLAG(ifp->status, ZEBRA_INTERFACE_DUMMY);
+
 	if (!CHECK_FLAG(ifp->status, ZEBRA_INTERFACE_ACTIVE)) {
 		SET_FLAG(ifp->status, ZEBRA_INTERFACE_ACTIVE);
 
@@ -1616,6 +1619,7 @@ static void interface_update_l2info(struct zebra_dplane_ctx *ctx,
 	case ZEBRA_IF_MACVLAN:
 	case ZEBRA_IF_VETH:
 	case ZEBRA_IF_BOND:
+	case ZEBRA_IF_DUMMY:
 		break;
 	}
 }
@@ -2369,6 +2373,9 @@ static const char *zebra_ziftype_2str(enum zebra_iftype zif_type)
 	case ZEBRA_IF_GRE:
 		return "GRE";
 
+	case ZEBRA_IF_DUMMY:
+		return "dummy";
+
 	default:
 		return "Unknown";
 	}

diff --git a/zebra/interface.h b/zebra/interface.h
@@ -39,7 +39,8 @@ enum zebra_iftype {
 	ZEBRA_IF_MACVLAN,   /* MAC VLAN interface*/
 	ZEBRA_IF_VETH,      /* VETH interface*/
 	ZEBRA_IF_BOND,	    /* Bond */
-	ZEBRA_IF_GRE,      /* GRE interface */
+	ZEBRA_IF_GRE,       /* GRE interface */
+	ZEBRA_IF_DUMMY,     /* Dummy interface */
 };
 
 /* Zebra "slave" interface type */
@@ -246,6 +247,9 @@ DECLARE_HOOK(zebra_if_extra_info, (struct vty * vty, struct interface *ifp),
 #define IS_ZEBRA_IF_GRE(ifp)                                               \
 	(((struct zebra_if *)(ifp->info))->zif_type == ZEBRA_IF_GRE)
 
+#define IS_ZEBRA_IF_DUMMY(ifp)                                               \
+	(((struct zebra_if *)(ifp->info))->zif_type == ZEBRA_IF_DUMMY)
+
 #define IS_ZEBRA_IF_BRIDGE_SLAVE(ifp)					\
 	(((struct zebra_if *)(ifp->info))->zif_slave_type                      \
 	 == ZEBRA_IF_SLAVE_BRIDGE)

diff --git a/zebra/zebra_nb_state.c b/zebra/zebra_nb_state.c
@@ -87,6 +87,9 @@ lib_interface_zebra_state_zif_type_get_elem(struct nb_cb_get_elem_args *args)
 	case ZEBRA_IF_GRE:
 		type = "frr-zebra:zif-gre";
 		break;
+	case ZEBRA_IF_DUMMY:
+		type = "frr-zebra:zif-dummy";
+		break;
 	}
 
 	if (!type)