Disable neighbour acquisition

babeld.c

@@ -70,6 +70,7 @@ int resend_delay = -1;
 int random_id = 0;
 int do_daemonise = 0;
 int skip_kernel_setup = 0;
+int neighbour_acquisition = 1;
 const char *logfile = NULL,
     *pidfile = "/var/run/babeld.pid",
     *state_file = "/var/lib/babel-state";

babeld.h

@@ -92,6 +92,7 @@ extern const char *logfile, *pidfile, *state_file;
 extern int link_detect;
 extern int all_wireless;
 extern int has_ipv6_subtrees;
+extern int neighbour_acquisition;
 
 extern unsigned char myid[8];
 extern int have_id;

babeld.man

@@ -317,6 +317,19 @@ source-specific routes.  The default is 10.
 .BI first-rule-priority " priority"
 This specifies smallest (highest) rule priority used with source-specific
 routes.  The default is 100.
+.TP
+.BR neighbour-acquisition " {" true | false }
+If this flag is set to
+.BR false ,
+no neighbour acquisition is done (e.g., via Multicast Hellos), and
+neighbours must be added via an external mechanism. The default is
+.BR true .
+.TP
+.BI neighbour " address ifname"
+Add the neighbour with given
+.I address
+to the interface
+.IR ifname .
 .SS Interface configuration
 An interface is configured by a line with the following format:
 .IP
@@ -614,6 +627,9 @@ any configuration file directive, including
 .IP \(bu
 .BR "flush interface" ;
 .IP \(bu
+.B "flush neighbour"
+.IR "address ifname" ;
+.IP \(bu
 .BR dump ;
 .IP \(bu
 .B monitor

configuration.c

@@ -37,6 +37,7 @@ THE SOFTWARE.
 #include "babeld.h"
 #include "util.h"
 #include "interface.h"
+#include "neighbour.h"
 #include "route.h"
 #include "kernel.h"
 #include "configuration.h"
@@ -850,7 +851,8 @@ parse_option(int c, gnc_t gnc, void *closure, char *token)
               strcmp(token, "daemonise") == 0 ||
               strcmp(token, "skip-kernel-setup") == 0 ||
               strcmp(token, "ipv6-subtrees") == 0 ||
-              strcmp(token, "reflect-kernel-metric") == 0) {
+              strcmp(token, "reflect-kernel-metric") == 0 ||
+              strcmp(token, "neighbour-acquisition") == 0) {
         int b;
         c = getbool(c, &b, gnc, closure);
         if(c < -1)
@@ -868,6 +870,8 @@ parse_option(int c, gnc_t gnc, void *closure, char *token)
             has_ipv6_subtrees = b;
         else if(strcmp(token, "reflect-kernel-metric") == 0)
             reflect_kernel_metric = b;
+        else if(strcmp(token, "neighbour-acquisition") == 0)
+            neighbour_acquisition = b;
         else
             abort();
     } else if(strcmp(token, "protocol-group") == 0) {
@@ -969,6 +973,41 @@ parse_option(int c, gnc_t gnc, void *closure, char *token)
 
 }
 
+static int
+parse_neighbour(int c, gnc_t gnc, void *closure,
+                unsigned char **address_return, struct interface **ifp_return)
+{
+    char *ifname = NULL;
+    struct interface *ifp;
+    *address_return = NULL;
+    *ifp_return = NULL;
+
+    c = skip_whitespace(c, gnc, closure);
+    c = getip(c, address_return, NULL, gnc, closure);
+    if(c < -1)
+        return c;
+    c = getword(c, &ifname, gnc, closure);
+    c = skip_eol(c, gnc, closure);
+    if(c < -1) {
+        free(*address_return);
+        *address_return = NULL;
+        return c;
+    }
+
+    FOR_ALL_INTERFACES(ifp) {
+        if(strcmp(ifp->name, ifname) == 0)
+            break;
+    }
+    *ifp_return = ifp;
+    if(ifp == NULL) {
+        fprintf(stderr, "Couldn't find interface %s.\n", ifname);
+        free(*address_return);
+        *address_return = NULL;
+    }
+    free(ifname);
+    return c;
+}
+
 static int
 parse_config_line(int c, gnc_t gnc, void *closure,
                   int *action_return, const char **message_return)
@@ -1068,6 +1107,19 @@ parse_config_line(int c, gnc_t gnc, void *closure,
                          if_conf, default_interface_conf);
             free(if_conf);
         }
+    } else if(strcmp(token, "neighbour") == 0) {
+        unsigned char *address;
+        struct interface *ifp;
+        struct neighbour *neigh;
+        c = parse_neighbour(c, gnc, closure, &address, &ifp);
+        if(c < -1 || address == NULL || ifp == NULL)
+            goto fail;
+        neigh = find_neighbour(address, ifp);
+        free(address);
+        if(neigh == NULL) {
+            fprintf(stderr, "Couldn't allocate neighbour.\n");
+            goto fail;
+        }
     } else if(strcmp(token, "flush") == 0) {
         char *token2;
         c = skip_whitespace(c, gnc, closure);
@@ -1097,6 +1149,22 @@ parse_config_line(int c, gnc_t gnc, void *closure,
             }
             free(token2);
             free(ifname);
+        } else if(strcmp(token2, "neighbour") == 0) {
+            unsigned char *address;
+            struct interface *ifp;
+            int rc;
+            free(token2);
+            c = parse_neighbour(c, gnc, closure, &address, &ifp);
+            if(c < -1 || address == NULL || ifp == NULL)
+                goto fail;
+            rc = flush_neighbour2(address, ifp);
+            if(rc) {
+                if(action_return)
+                    *action_return = CONFIG_ACTION_NO;
+                if(message_return)
+                    *message_return = "No such neighbour";
+            }
+            free(address);
         } else {
             free(token2);
             goto fail;

message.c

@@ -495,10 +495,19 @@ parse_packet(const unsigned char *from, struct interface *ifp,
         bodylen = packetlen - 4;
     }
 
-    neigh = find_neighbour(from, ifp);
-    if(neigh == NULL) {
-        fprintf(stderr, "Couldn't allocate neighbour.\n");
-        return;
+    if(neighbour_acquisition) {
+        neigh = find_neighbour(from, ifp);
+        if(neigh == NULL) {
+            fprintf(stderr, "Couldn't allocate neighbour.\n");
+            return;
+        }
+    } else {
+        neigh = find_neighbour_nocreate(from, ifp);
+        if(neigh == NULL) {
+            fprintf(stderr, "Couldn't find neighbour %s on %s.\n",
+                    format_address(from), ifp->name);
+            return;
+        }
     }
 
     i = 0;
@@ -1082,7 +1091,7 @@ buffer_hello(struct buffered *buf, struct interface *ifp,
 void
 send_multicast_hello(struct interface *ifp, unsigned interval, int force)
 {
-    if(!if_up(ifp))
+    if(!neighbour_acquisition || !if_up(ifp))
         return;
 
     if(interval == 0 && (ifp->flags & IF_RFC6126) != 0)

neighbour.c

@@ -41,7 +41,7 @@ THE SOFTWARE.
 
 struct neighbour *neighs = NULL;
 
-static struct neighbour *
+struct neighbour *
 find_neighbour_nocreate(const unsigned char *address, struct interface *ifp)
 {
     struct neighbour *neigh;
@@ -72,6 +72,27 @@ flush_neighbour(struct neighbour *neigh)
     free(neigh);
 }
 
+int
+flush_neighbour2(const unsigned char *address, const struct interface *ifp)
+{
+    struct neighbour **neigh = &neighs, *flush;
+
+    while(*neigh != NULL &&
+          memcmp(address, (*neigh)->address, 16) != 0 &&
+          ifp != (*neigh)->ifp)
+        neigh = &(*neigh)->next;
+    flush = *neigh;
+    if(flush == NULL)
+        return -1;
+    *neigh = flush->next;
+    flush_neighbour_routes(flush);
+    flush_resends(flush);
+    local_notify_neighbour(flush, LOCAL_FLUSH);
+    free(flush->buf.buf);
+    free(flush);
+    return 0;
+}
+
 struct neighbour *
 find_neighbour(const unsigned char *address, struct interface *ifp)
 {

neighbour.h

@@ -54,6 +54,9 @@ extern struct neighbour *neighs;
     for(_neigh = neighs; _neigh; _neigh = _neigh->next)
 
 void flush_neighbour(struct neighbour *neigh);
+int flush_neighbour2(const unsigned char *address, const struct interface *ifp);
+struct neighbour *find_neighbour_nocreate(const unsigned char *address,
+                                          struct interface *ifp);
 struct neighbour *find_neighbour(const unsigned char *address,
                                  struct interface *ifp);
 int update_neighbour(struct neighbour *neigh, struct hello_history *hist,