Refactor netlink: routes import.

babeld.c

@@ -94,11 +94,17 @@ struct timeval check_neighbours_timeout, check_interfaces_timeout;
 static volatile sig_atomic_t exiting = 0, dumping = 0, reopening = 0;
 
 static int accept_local_connections(fd_set *readfds);
-static int kernel_routes_callback(int changed, void *closure);
 static void init_signals(void);
 static void dump_tables(FILE *out);
 static int reopen_logfile(void);
 
+static int
+kernel_route_notify(struct kernel_route *route, void *closure)
+{
+    kernel_routes_changed = 1;
+    return -1;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -588,8 +594,11 @@ main(int argc, char **argv)
         if(exiting)
             break;
 
-        if(kernel_socket >= 0 && FD_ISSET(kernel_socket, &readfds))
-            kernel_callback(kernel_routes_callback, NULL);
+        if(kernel_socket >= 0 && FD_ISSET(kernel_socket, &readfds)) {
+            struct kernel_filter filter = {0};
+            filter.route = kernel_route_notify;
+            kernel_callback(&filter);
+        }
 
         if(FD_ISSET(protocol_socket, &readfds)) {
             rc = babel_recv(protocol_socket,
@@ -1108,17 +1117,3 @@ reopen_logfile()
 
     return 1;
 }
-
-static int
-kernel_routes_callback(int changed, void *closure)
-{
-    if(changed & CHANGE_LINK)
-        kernel_link_changed = 1;
-    if(changed & CHANGE_ADDR)
-        kernel_addr_changed = 1;
-    if(changed & CHANGE_ROUTE)
-        kernel_routes_changed = 1;
-    if(changed & CHANGE_RULE)
-        kernel_rules_changed = 1;
-    return 1;
-}

kernel.h

@@ -36,6 +36,12 @@ struct kernel_route {
     unsigned char gw[16];
 };
 
+struct kernel_filter {
+    /* return -1 to interrupt search. */
+    int (*route)(struct kernel_route *, void *);
+    void *route_closure;
+};
+
 #define ROUTE_FLUSH 0
 #define ROUTE_ADD 1
 #define ROUTE_MODIFY 2
@@ -71,8 +77,8 @@ int kernel_route(int operation, const unsigned char *dest, unsigned short plen,
                  const unsigned char *gate, int ifindex, unsigned int metric,
                  const unsigned char *newgate, int newifindex,
                  unsigned int newmetric);
-int kernel_routes(struct kernel_route *routes, int maxroutes);
-int kernel_callback(int (*fn)(int, void*), void *closure);
+int kernel_dump(int operation, struct kernel_filter *filter);
+int kernel_callback(struct kernel_filter *filter);
 int kernel_addresses(char *ifname, int ifindex, int ll,
                      struct kernel_route *routes, int maxroutes);
 int if_eui64(char *ifname, int ifindex, unsigned char *eui);

kernel_netlink.c

@@ -89,6 +89,7 @@ static int dgram_socket = -1;
 #define NO_ARPHRD
 #endif
 
+static int filter_netlink(struct nlmsghdr *nh, struct kernel_filter *filter);
 
 static int find_table(const unsigned char *src, unsigned short src_plen);
 static void release_tables(void);
@@ -899,7 +900,7 @@ kernel_route(int operation, const unsigned char *dest, unsigned short plen,
     struct rtmsg *rtm;
     struct rtattr *rta;
     int len = sizeof(buf.raw);
-    int rc, ipv4, table, use_src = 0;
+    int rc, ipv4, use_src = 0;
 
     if(!nl_setup) {
         fprintf(stderr,"kernel_route: netlink not initialized.\n");
@@ -1170,34 +1171,15 @@ print_kernel_route(int add, int protocol, int type,
 }
 
 static int
-filter_kernel_routes(struct nlmsghdr *nh, void *data)
+filter_kernel_routes(struct nlmsghdr *nh, struct kernel_route *route)
 {
-    int rc;
-
-    struct kernel_route *current_route;
-    struct kernel_route route;
-
-    int maxroutes = 0;
-    struct kernel_route *routes = NULL;
-    int *found = NULL;
-    int len;
-
+    int rc, len;
     struct rtmsg *rtm;
 
-    if(data) {
-        void **args = (void**)data;
-        maxroutes = *(int*)args[0];
-        routes = (struct kernel_route *)args[1];
-        found = (int*)args[2];
-    }
-
     len = nh->nlmsg_len;
 
-    if(data && *found >= maxroutes)
-        return 0;
-
     if(nh->nlmsg_type != RTM_NEWROUTE &&
-       (data || nh->nlmsg_type != RTM_DELROUTE))
+       nh->nlmsg_type != RTM_DELROUTE)
         return 0;
 
     rtm = (struct rtmsg*)NLMSG_DATA(nh);
@@ -1210,50 +1192,35 @@ filter_kernel_routes(struct nlmsghdr *nh, void *data)
     if(rtm->rtm_flags & RTM_F_CLONED)
         return 0;
 
-    if(data)
-        current_route = &routes[*found];
-    else
-        current_route = &route;
-
-    rc = parse_kernel_route_rta(rtm, len, current_route);
+    rc = parse_kernel_route_rta(rtm, len, route);
     if(rc < 0)
         return 0;
 
-    if(martian_prefix(current_route->prefix, current_route->plen) ||
-       martian_prefix(current_route->src_prefix, current_route->src_plen))
-        return 0;
-
     /* Ignore default unreachable routes; no idea where they come from. */
-    if(current_route->plen == 0 && current_route->metric >= KERNEL_INFINITY)
+    if(route->plen == 0 && route->metric >= KERNEL_INFINITY)
         return 0;
 
     if(debug >= 2) {
         if(rc >= 0) {
             print_kernel_route(nh->nlmsg_type, rtm->rtm_protocol,
-                               rtm->rtm_type, current_route);
+                               rtm->rtm_type, route);
         }
     }
 
-    if(data) *found = (*found)+1;
-
     return 1;
 
 }
 
 /* This function should not return routes installed by us. */
 int
-kernel_routes(struct kernel_route *routes, int maxroutes)
+kernel_dump(int operation, struct kernel_filter *filter)
 {
     int i, rc;
-    int maxr = maxroutes;
-    int found = 0;
-    void *data[3] = { &maxr, routes, &found };
     int families[2] = { AF_INET6, AF_INET };
-    char rule_exists[SRC_TABLE_NUM] = {0};
     struct rtgenmsg g;
 
     if(!nl_setup) {
-        fprintf(stderr,"kernel_routes: netlink not initialized.\n");
+        fprintf(stderr,"kernel_dump: netlink not initialized.\n");
         errno = EIO;
         return -1;
     }
@@ -1261,7 +1228,7 @@ kernel_routes(struct kernel_route *routes, int maxroutes)
     if(nl_command.sock < 0) {
         rc = netlink_socket(&nl_command, 0);
         if(rc < 0) {
-            perror("kernel_routes: netlink_socket()");
+            perror("kernel_dump: netlink_socket()");
             return -1;
         }
     }
@@ -1269,28 +1236,32 @@ kernel_routes(struct kernel_route *routes, int maxroutes)
     for(i = 0; i < 2; i++) {
         memset(&g, 0, sizeof(g));
         g.rtgen_family = families[i];
-        rc = netlink_send_dump(RTM_GETROUTE, &g, sizeof(g));
-        if(rc < 0)
-            return -1;
-
-        rc = netlink_read(&nl_command, NULL, 1,
-                          filter_kernel_routes, (void *)data);
-        if(rc < 0)
-            return -1;
+        if(operation & CHANGE_ROUTE) {
+            rc = netlink_send_dump(RTM_GETROUTE, &g, sizeof(g));
+            if(rc < 0)
+                return -1;
 
-        rc = netlink_send_dump(RTM_GETRULE, &g, sizeof(g));
-        if(rc < 0)
-            return -1;
+            rc = netlink_read(&nl_command, NULL, 1,
+                              filter_netlink, (void *)filter);
+            if(rc < 0)
+                return -1;
+        }
 
-        rc = netlink_read(&nl_command, NULL, 1,
-                          filter_kernel_rules, rule_exists);
-        if(rc < 0)
-            return -1;
+        memset(&g, 0, sizeof(g));
+        g.rtgen_family = families[i];
+        if(operation & CHANGE_RULE) {
+            rc = netlink_send_dump(RTM_GETRULE, &g, sizeof(g));
+            if(rc < 0)
+                return -1;
 
-        install_missing_rules(rule_exists, families[i] == AF_INET);
+            rc = netlink_read(&nl_command, NULL, 1,
+                              filter_kernel_rules, rule_exists);
+            if(rc < 0)
+                return -1;
+        }
     }
 
-    return found;
+    return 0;
 }
 
 static char *
@@ -1450,18 +1421,21 @@ filter_addresses(struct nlmsghdr *nh, void *data)
 }
 
 static int
-filter_netlink(struct nlmsghdr *nh, void *data)
+filter_netlink(struct nlmsghdr *nh, struct kernel_filter *filter)
 {
     int rc;
     int *changed = data;
+    union {
+        struct kernel_route route;
+    } u;
 
     switch(nh->nlmsg_type) {
     case RTM_NEWROUTE:
     case RTM_DELROUTE:
-        rc = filter_kernel_routes(nh, NULL);
-        if(changed && rc > 0)
-            *changed |= CHANGE_ROUTE;
-        return rc;
+        if(!filter->route) break;
+        rc = filter_kernel_routes(nh, &u.route);
+        if(rc <= 0) break;
+        return filter->route(&u.route, filter->route_closure);
     case RTM_NEWLINK:
     case RTM_DELLINK:
         rc = filter_link(nh, NULL);
@@ -1470,7 +1444,7 @@ filter_netlink(struct nlmsghdr *nh, void *data)
         return rc;
     case RTM_NEWADDR:
     case RTM_DELADDR:
-        rc = filter_addresses(nh, NULL);
+        rc = filter_addresses(nh, &kernel_addr);
         if(changed && rc > 0)
             *changed |= CHANGE_ADDR;
         return rc;
@@ -1529,10 +1503,9 @@ kernel_addresses(char *ifname, int ifindex, int ll,
 }
 
 int
-kernel_callback(int (*fn)(int, void*), void *closure)
+kernel_callback(struct kernel_filter *filter)
 {
     int rc;
-    int changed = 0;
 
     kdebugf("\nReceived changes in kernel tables.\n");
 
@@ -1543,16 +1516,12 @@ kernel_callback(int (*fn)(int, void*), void *closure)
             return -1;
         }
     }
-    rc = netlink_read(&nl_listen, &nl_command, 0, filter_netlink, &changed);
+    rc = netlink_read(&nl_listen, &nl_command, 0, filter_netlink,
+                      (void*) filter);
 
     if(rc < 0 && nl_listen.sock < 0)
         kernel_setup_socket(1);
 
-    /* if netlink return 0 (found something interesting) */
-    /* or -1 (i.e. IO error), we call... back ! */
-    if(rc)
-        return fn(changed, closure);
-
     return 0;
 }
 

kernel_socket.c

@@ -688,13 +688,13 @@ parse_kernel_route(const struct rt_msghdr *rtm, struct kernel_route *route)
 }
 
 int
-kernel_routes(struct kernel_route *routes, int maxroutes)
+kernel_dump(int operation, struct kernel_filter *filter)
 {
     int mib[6];
     char *buf, *p;
     size_t len;
     struct rt_msghdr *rtm;
-    int rc, i;
+    int rc;
 
     mib[0] = CTL_NET;
     mib[1] = PF_ROUTE;
@@ -721,21 +721,23 @@ kernel_routes(struct kernel_route *routes, int maxroutes)
         goto fail;
     }
 
-    i = 0;
-    for(p = buf; p < buf + len && i < maxroutes; p += rtm->rtm_msglen) {
+    for(p = buf; p < buf + len; p += rtm->rtm_msglen) {
+        struct kernel_route route;
         rtm = (struct rt_msghdr*)p;
-        rc = parse_kernel_route(rtm, &routes[i]);
+        rc = parse_kernel_route(rtm, &route);
         if(rc < 0)
             continue;
 
         if(debug > 2)
-            print_kernel_route(1,&routes[i]);
+            print_kernel_route(1, &route);
 
-        i++;
+        rc = filter->route(&route, filter->route_closure);
+        if(rc < 0)
+            break;
     }
 
     free(buf);
-    return i;
+    return 0;
 
  fail:
     free(buf);
@@ -744,7 +746,7 @@ kernel_routes(struct kernel_route *routes, int maxroutes)
 }
 
 static int
-socket_read(int sock)
+socket_read(int sock, struct kernel_filter *filter)
 {
     int rc;
     struct {
@@ -774,6 +776,7 @@ socket_read(int sock)
         rc = parse_kernel_route(&buf.rtm, &route);
         if(rc < 0)
             return 0;
+        filter->route(&route, filter->route_closure);
         if(debug > 2)
             print_kernel_route(1,&route);
         return 1;
@@ -843,16 +846,12 @@ kernel_addresses(char *ifname, int ifindex, int ll,
 }
 
 int
-kernel_callback(int (*fn)(int, void*), void *closure)
+kernel_callback(struct kernel_filter *filter)
 {
-    int rc;
-
     if(kernel_socket < 0) kernel_setup_socket(1);
 
     kdebugf("Reading kernel table modification.");
-    rc = socket_read(kernel_socket);
-    if(rc)
-        return fn(~0, closure);
+    socket_read(kernel_socket, filter);
 
     return 0;
 

xroute.c

@@ -164,6 +164,40 @@ xroute_stream_done(struct xroute_stream *stream)
     free(stream);
 }
 
+static int
+filter_route(struct kernel_route *route, void *data) {
+    void **args = (void**)data;
+    int maxroutes = *(int*)args[0];
+    struct kernel_route *routes = (struct kernel_route *)args[1];
+    int *found = (int*)args[2];
+
+    if(*found >= maxroutes)
+        return -1;
+
+    if(martian_prefix(route->prefix, route->plen) ||
+       martian_prefix(route->src_prefix, route->src_plen))
+        return 0;
+
+    routes[*found] = *route;
+    ++ *found;
+
+    return 0;
+}
+
+static int
+kernel_routes(struct kernel_route *routes, int maxroutes)
+{
+    int found = 0;
+    void *data[3] = { &maxroutes, routes, &found };
+    struct kernel_filter filter = {0};
+    filter.route = filter_route;
+    filter.route_closure = data;
+
+    kernel_dump(CHANGE_ROUTE, &filter);
+
+    return found;
+}
+
 int
 check_xroutes(int send_updates)
 {