babeld: add remove_interface function

Add the ubus function to remove an interface from babeld:
    ubus call babeld remove_interface '{"ifname":"eth0"}'

Signed-off-by: Nick Hainke <[email protected]>

babeld/patches/100-interface-local-add-remove-interface-function.patch

@@ -0,0 +1,78 @@
+From 2f75f3d7073bad9b4b0c031aa792013fd6b61c19 Mon Sep 17 00:00:00 2001
+From: Polynomialdivision <[email protected]>
+Date: Tue, 1 Feb 2022 22:37:29 +0100
+Subject: [PATCH] interface/local: add remove_interface function
+
+Babeld can add interfaces dynamically. However, babeld is missing a
+function to remove interfaces and stop meshing on them. Add a function
+that can do it.
+
+Signed-off-by: Nick Hainke <[email protected]>
+---
+ interface.c | 33 +++++++++++++++++++++++++++++++++
+ interface.h |  1 +
+ local.h     |  1 +
+ 3 files changed, 35 insertions(+)
+
+--- a/interface.c
++++ b/interface.c
+@@ -94,6 +94,39 @@ add_interface(char *ifname, struct inter
+     return ifp;
+ }
+
++void
++remove_interface(char *ifname)
++{
++    struct interface *tmp_ifp, *ifp = NULL;
++
++    if(interfaces == NULL)
++        return;
++
++    if(strcmp(interfaces->name, ifname) == 0) {
++        tmp_ifp = interfaces;
++        interface_updown(tmp_ifp, 0);
++        interfaces = tmp_ifp->next;
++        free(tmp_ifp);
++        return;
++    }
++
++    FOR_ALL_INTERFACES(ifp) {
++        if(ifp->next == NULL)
++            break;
++        if(strcmp(ifp->next->name, ifname) == 0) {
++            break;
++        }
++    }
++
++    if(ifp->next == NULL)
++        return;
++
++    tmp_ifp = ifp->next;
++    interface_updown(tmp_ifp, 0);
++    ifp->next = tmp_ifp->next;
++    free(tmp_ifp);
++}
++
+ int
+ flush_interface(char *ifname)
+ {
+--- a/interface.h
++++ b/interface.h
+@@ -147,6 +147,7 @@ if_up(struct interface *ifp)
+ }
+
+ struct interface *add_interface(char *ifname, struct interface_conf *if_conf);
++void remove_interface(char *ifname);
+ int flush_interface(char *ifname);
+ unsigned jitter(struct buffered *buf, int urgent);
+ unsigned update_jitter(struct interface *ifp, int urgent);
+--- a/local.h
++++ b/local.h
+@@ -27,6 +27,7 @@ struct xroute;
+ #define LOCAL_FLUSH 0
+ #define LOCAL_ADD 1
+ #define LOCAL_CHANGE 2
++#define LOCAL_REMOVE 3
+
+ #ifndef MAX_LOCAL_SOCKETS
+ #define MAX_LOCAL_SOCKETS 4

babeld/src/ubus.c

@@ -89,6 +89,30 @@ static int babeld_ubus_add_interface(struct ubus_context *ctx_local,
   return UBUS_STATUS_OK;
 }
 
+// Remove an inteface (ubus equivalent to "interface"-function).
+static int babeld_ubus_remove_interface(struct ubus_context *ctx_local,
+                                        struct ubus_object *obj,
+                                        struct ubus_request_data *req,
+                                        const char *method,
+                                        struct blob_attr *msg) {
+  struct blob_attr *tb[__INTERFACE_MAX];
+  struct blob_buf b = {0};
+  struct interface *ifp = NULL;
+  char *ifname;
+
+  blobmsg_parse(interface_policy, __INTERFACE_MAX, tb, blob_data(msg),
+                blob_len(msg));
+
+  if (!tb[INTERFACE_IFNAME])
+    return UBUS_STATUS_INVALID_ARGUMENT;
+
+  ifname = blobmsg_get_string(tb[INTERFACE_IFNAME]);
+
+  remove_interface(ifname);
+
+  return UBUS_STATUS_OK;
+}
+
 // Sends a babel info message on ubus socket.
 static int babeld_ubus_babeld_info(struct ubus_context *ctx_local,
                                    struct ubus_object *obj,
@@ -364,6 +388,8 @@ static int babeld_ubus_get_neighbours(struct ubus_context *ctx_local,
 // List of functions we expose via the ubus bus.
 static const struct ubus_method babeld_methods[] = {
     UBUS_METHOD("add_interface", babeld_ubus_add_interface, interface_policy),
+    UBUS_METHOD("remove_interface", babeld_ubus_remove_interface,
+                interface_policy),
     UBUS_METHOD_NOARG("get_info", babeld_ubus_babeld_info),
     UBUS_METHOD_NOARG("get_xroutes", babeld_ubus_get_xroutes),
     UBUS_METHOD_NOARG("get_routes", babeld_ubus_get_routes),