[WIP] Add manual reload functionality to mrouted for hotplugged network interfaces

src/config.c

@@ -10,6 +10,7 @@
 #include <ifaddrs.h>
 #include "defs.h"
 
+static TAILQ_HEAD(, uvif) cvifs = TAILQ_HEAD_INITIALIZER(cvifs);
 static TAILQ_HEAD(, uvif) vifs = TAILQ_HEAD_INITIALIZER(vifs);
 
 void config_set_ifflag(uint32_t flag)
@@ -127,6 +128,22 @@ struct uvif *config_init_tunnel(in_addr_t lcl_addr, in_addr_t rmt_addr, uint32_t
     return uv;
 }
 
+/*
+ * Find index of an already installed vif.
+ */
+static vifi_t find_vifi(struct uvif *v)
+{
+    struct uvif *uv;
+    vifi_t vifi;
+
+    UVIF_FOREACH(vifi, uv) {
+        if (strcmp(v->uv_name, uv->uv_name) == 0) {
+            return vifi;
+        }
+    }
+    return NO_VIF;
+}
+
 /*
  * Ignore any kernel interface that is disabled, or connected to the
  * same subnet as one already installed in the uvifs[] array.
@@ -183,6 +200,61 @@ static vifi_t check_vif(struct uvif *v)
     return vifi;
 }
 
+static void reload_gone_vifs(void)
+{
+    struct uvif *uv;
+    struct uvif *nuv;
+
+    int found;
+    TAILQ_FOREACH(uv, &cvifs, uv_link) {
+        found = 0;
+        TAILQ_FOREACH(nuv, &vifs, uv_link) {	
+            if (uv->uv_ifindex == nuv->uv_ifindex) {
+                found = 1;
+                break;
+            }
+        }
+        if (!found) {
+			vifi_t vifi = find_vifi(uv);
+			if (vifi == NO_VIF) {
+                TAILQ_REMOVE(&vifs, uv, uv_link);
+                free(uv);
+                continue;
+            }
+            stop_vif(vifi);
+            uninstall_uvif(uv);
+        }
+    }
+}
+
+static void reload_new_vifs(void)
+{
+    struct uvif *uv;
+    struct uvif *nuv;
+
+    int found;
+    TAILQ_FOREACH(nuv, &vifs, uv_link) {
+        found = 0;
+        TAILQ_FOREACH(uv, &cvifs, uv_link) {	
+            if (uv->uv_ifindex == nuv->uv_ifindex) {
+                found = 1;
+                break;
+            }
+        }
+        if (!found) {
+            vifi_t vifi = check_vif(nuv);
+            if (vifi == NO_VIF || install_uvif(nuv)) {
+                TAILQ_REMOVE(&vifs, nuv, uv_link);
+                free(nuv);
+                continue;
+            }
+			init_installvif(nuv, vifi);
+			start_vif2(vifi);
+        }
+    }
+}
+
+
 void config_vifs_correlate(void)
 {
     struct listaddr *al, *al_tmp;
@@ -209,11 +281,19 @@ void config_vifs_correlate(void)
 		  vifi, v->uv_rate_limit);
     }
 
-    /*
-     * XXX: one future extension may be to keep this for adding/removing
-     *      dynamic interfaces at runtime.  Now we re-init and let SIGHUP
-     *      rebuild it to recheck since we tear down all vifs anyway.
-     */
+    TAILQ_FIRST(&cvifs) = TAILQ_FIRST(&vifs);
+    TAILQ_INIT(&vifs);
+}
+
+
+void config_vifs_from_reload()
+{
+    config_vifs_from_kernel();
+    reload_gone_vifs();
+    reload_new_vifs();
+
+    TAILQ_INIT(&cvifs);
+    TAILQ_FIRST(&cvifs) = TAILQ_FIRST(&vifs);
     TAILQ_INIT(&vifs);
 }
 

src/defs.h

@@ -256,6 +256,8 @@ extern int		mrt_table_id;
 extern int              debug_list(int, char *, size_t);
 extern int              debug_parse(char *);
 extern void             restart(void);
+extern void             reload_iface(void);
+extern void             reload_vifs(void);
 extern char *		scaletime(time_t);
 extern int		register_input_handler(int, ihfunc_t);
 extern void		deregister_input_handler(int);
@@ -311,17 +313,21 @@ extern void		report_to_all_neighbors(int);
 extern int		report_next_chunk(void);
 extern void		add_vif_to_routes(vifi_t);
 extern void		delete_vif_from_routes(vifi_t);
+extern void		discard_vif_from_routes(vifi_t);
 extern void		add_neighbor_to_routes(vifi_t, uint32_t);
 extern void		delete_neighbor_from_routes(uint32_t, vifi_t, uint32_t);
 extern void		dump_routes(FILE *, int);
 
 /* vif.c */
 extern void		init_vifs(void);
+extern void     start_vif2(vifi_t);
+extern void     stop_vif(vifi_t);
 extern void		blaster_alloc(struct uvif *);
 extern void		blaster_free(struct uvif *);
 extern void		zero_vif(struct uvif *, int);
 extern void		init_installvifs(void);
 extern int		install_uvif(struct uvif *);
+extern int      uninstall_uvif(struct uvif *);
 extern void		check_vif_state(void);
 extern void		send_on_vif(struct uvif *, uint32_t, int, size_t);
 extern struct uvif     *find_uvif(vifi_t);
@@ -357,6 +363,7 @@ extern struct uvif     *config_find_ifaddr(in_addr_t addr);
 extern struct uvif     *config_init_tunnel(in_addr_t lcl_addr, in_addr_t rmt_addr, uint32_t flags);
 extern void		config_vifs_correlate(void);
 extern void		config_vifs_from_kernel(void);
+extern void     config_vifs_from_reload(void);
 
 /* cfparse.y */
 extern void		config_vifs_from_file(void);
@@ -452,6 +459,7 @@ extern int		pidfile(const char *basename);
 #define IPC_SHOW_MFC_CMD          21
 #define IPC_SHOW_NEIGH_CMD        22
 #define IPC_SHOW_ROUTES_CMD       23
+#define IPC_RELOAD_IFACE_CMD      30
 #define IPC_SHOW_COMPAT_CMD       250
 #define IPC_EOF_CMD               254
 #define IPC_ERR_CMD               255

src/ipc.c

@@ -618,6 +618,10 @@ static void ipc_handle(int sd)
 		restart();
 		break;
 
+	case IPC_RELOAD_IFACE_CMD:
+		reload_iface();
+		break;
+
 	case IPC_DEBUG_CMD:
 		ipc_generic(client, &msg, do_debug, &msg);
 		break;

src/main.c

@@ -504,7 +504,7 @@ int main(int argc, char *argv[])
     }
 
     logit(LOG_NOTICE, 0, "%s exiting", versionstring);
-    free(pfd);
+	free(pfd);
     cleanup();
 
     return 0;
@@ -803,6 +803,22 @@ void restart(void)
     timer_set(TIMER_INTERVAL, timer, NULL);
 }
 
+/*
+ * Reload ifaces
+ */
+void reload_iface(void)
+{
+    FILE *fp = NULL;
+    char *s = NULL;
+
+    s = strdup (" reload ifaces");
+    if (s == NULL)
+	logit(LOG_ERR, 0, "out of memory");
+
+    reload_vifs();
+}
+
+
 #define SCALETIMEBUFLEN 27
 char *scaletime(time_t t)
 {

src/mroutectl.c

@@ -320,6 +320,7 @@ static int usage(int rc)
 	       "  kill                    Kill running mrouted, like SIGTERM\n"
 	       "  log [? | none | LEVEL]  Set log level: none, err, notice*, info, debug\n"
 	       "  restart                 Restart mrouted and reload .conf file, like SIGHUP\n"
+	       "  reload ifaces           Reload listening interfaces\n"
 	       "  show version            Show version, and uptime (-d), of running mrouted\n"
 	       "  show status             Show status summary, default\n"
 	       "  show compat             Show status, compat mode, previously `mrouted -r`\n"
@@ -416,13 +417,18 @@ int main(int argc, char *argv[])
 		{ "version",    NULL, NULL,         IPC_VERSION_CMD         },
 		{ NULL, NULL, NULL, 0 }
 	};
+	struct cmd reload[] = {
+		{ "ifaces",     NULL, NULL,         IPC_RELOAD_IFACE_CMD    },
+		{ NULL, NULL, NULL, 0 }
+	};
 	struct cmd command[] = {
-		{ "debug",      NULL, set_debug,    0                       },
-		{ "help",       NULL, help,         0                       },
-		{ "kill",       NULL, NULL,         IPC_KILL_CMD            },
-		{ "log",        NULL, set_loglevel, 0                       },
-		{ "restart",    NULL, NULL,         IPC_RESTART_CMD         },
-		{ "show",       show, show_status,  0                       },
+		{ "debug",      NULL,   set_debug,    0                     },
+		{ "help",       NULL,   help,         0                     },
+		{ "kill",       NULL,   NULL,         IPC_KILL_CMD          },
+		{ "log",        NULL,   set_loglevel, 0                     },
+		{ "restart",    NULL,   NULL,         IPC_RESTART_CMD       },
+		{ "show",       show,   show_status,  0                     },
+		{ "reload",     reload, NULL,         0                     },
 		{ NULL, NULL, NULL, 0 }
 	};
 	int c;

src/route.c

@@ -163,6 +163,17 @@ void delete_vif_from_routes(vifi_t vifi)
 }
 
 
+void discard_vif_from_routes(vifi_t vifi)
+{
+    struct rtentry *r, *tmp;
+
+    TAILQ_FOREACH_SAFE(r, &rtable, rt_link, tmp) {
+		if (r->rt_parent == vifi || VIFM_ISSET(vifi, r->rt_children))
+            discard_route(r);
+    }
+}
+
+
 /*
  * A new neighbor has come up.  If we're flooding on the neighbor's
  * vif, mark that neighbor as subordinate for all routes whose parent
@@ -325,7 +336,6 @@ static void create_route(uint32_t origin, uint32_t mask)
     ++nroutes;
 }
 
-
 /*
  * Discard the routing table entry following the one to which 'rt' points.
  *         [.|prev|.]--->[.|rt|.]<---[.|next|.]