interface, ubus: rework netns up/down

Let per-container netifd instance handle the netns bringdown, it makes
everything easier and gets rid of the fork() when bringing down
container network interfaces.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/interface.c b/interface.c
index f60b545c7f5688b2417ccd865e56ace02daa9889..b3bb60121306006b21c917dee4f446bb2d5b20e3 100644 (file)
--- a/interface.c
+++ b/interface.c
@@ -35,7 +35,9 @@ enum {
        IFACE_ATTR_PROTO,
        IFACE_ATTR_AUTO,
        IFACE_ATTR_JAIL,
+       IFACE_ATTR_JAIL_DEVICE,
        IFACE_ATTR_JAIL_IFNAME,
+       IFACE_ATTR_HOST_DEVICE,
        IFACE_ATTR_DEFAULTROUTE,
        IFACE_ATTR_PEERDNS,
        IFACE_ATTR_DNS,
@@ -61,7 +63,9 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
        [IFACE_ATTR_IFNAME] = { .name = "ifname", .type = BLOBMSG_TYPE_STRING },
        [IFACE_ATTR_AUTO] = { .name = "auto", .type = BLOBMSG_TYPE_BOOL },
        [IFACE_ATTR_JAIL] = { .name = "jail", .type = BLOBMSG_TYPE_STRING },
+       [IFACE_ATTR_JAIL_DEVICE] = { .name = "jail_device", .type = BLOBMSG_TYPE_STRING },
        [IFACE_ATTR_JAIL_IFNAME] = { .name = "jail_ifname", .type = BLOBMSG_TYPE_STRING },
+       [IFACE_ATTR_HOST_DEVICE] = { .name = "host_device", .type = BLOBMSG_TYPE_STRING },
        [IFACE_ATTR_DEFAULTROUTE] = { .name = "defaultroute", .type = BLOBMSG_TYPE_BOOL },
        [IFACE_ATTR_PEERDNS] = { .name = "peerdns", .type = BLOBMSG_TYPE_BOOL },
        [IFACE_ATTR_METRIC] = { .name = "metric", .type = BLOBMSG_TYPE_INT32 },
@@ -698,8 +702,10 @@ interface_do_free(struct interface *iface)
        avl_delete(&interfaces.avl, &iface->node.avl);
        if (iface->jail)
                free(iface->jail);
-       if (iface->jail_ifname)
-               free(iface->jail_ifname);
+       if (iface->jail_device)
+               free(iface->jail_device);
+       if (iface->host_device)
+               free(iface->host_device);
 
        free(iface);
 }
@@ -914,9 +920,15 @@ interface_alloc(const char *name, struct blob_attr *config, bool dynamic)
                iface->autostart = false;
        }
 
-       iface->jail_ifname = NULL;
-       if ((cur = tb[IFACE_ATTR_JAIL_IFNAME]))
-               iface->jail_ifname = strdup(blobmsg_get_string(cur));
+       iface->jail_device = NULL;
+       if ((cur = tb[IFACE_ATTR_JAIL_DEVICE]))
+               iface->jail_device = strdup(blobmsg_get_string(cur));
+       else if ((cur = tb[IFACE_ATTR_JAIL_IFNAME]))
+               iface->jail_device = strdup(blobmsg_get_string(cur));
+
+       iface->host_device = NULL;
+       if ((cur = tb[IFACE_ATTR_HOST_DEVICE]))
+               iface->host_device = strdup(blobmsg_get_string(cur));
 
        return iface;
 }
@@ -1162,70 +1174,29 @@ interface_start_pending(void)
 }
 
 void
-interface_start_jail(const char *jail, const pid_t netns_pid)
+interface_start_jail(int netns_fd, const char *jail)
 {
        struct interface *iface;
-       int netns_fd;
-       int wstatus;
-       pid_t pr = 0;
-
-       netns_fd = system_netns_open(netns_pid);
-       if (netns_fd < 0)
-               return;
 
        vlist_for_each_element(&interfaces, iface, node) {
                if (!iface->jail || strcmp(iface->jail, jail))
                        continue;
 
-               system_link_netns_move(iface->main_dev.dev, netns_fd, iface->jail_ifname);
+               system_link_netns_move(iface->main_dev.dev, netns_fd, iface->jail_device);
        }
-
-       close(netns_fd);
 }
 
 void
-interface_stop_jail(const char *jail, const pid_t netns_pid)
+interface_stop_jail(int netns_fd)
 {
        struct interface *iface;
-       int netns_fd, root_netns;
-       int wstatus;
-       pid_t parent_pid = getpid();
-       pid_t pr = 0;
-       const char *orig_ifname;
-
-       pr = fork();
-       if (pr) {
-               waitpid(pr, &wstatus, WUNTRACED | WCONTINUED);
-               return;
-       }
-
-       /* child process */
-       root_netns = system_netns_open(parent_pid);
-       if (root_netns < 0)
-               return;
-
-       netns_fd = system_netns_open(netns_pid);
-       if (netns_fd < 0)
-               return;
+       char *orig_ifname;
 
-       system_netns_set(netns_fd);
-       system_init();
        vlist_for_each_element(&interfaces, iface, node) {
-               if (!iface->jail || strcmp(iface->jail, jail))
-                       continue;
-
-               orig_ifname = iface->device;
-               if (iface->jail_ifname)
-                       iface->device = iface->jail_ifname;
-
-               interface_do_reload(iface);
+               orig_ifname = iface->host_device;
                interface_set_down(iface);
-               system_link_netns_move(iface->main_dev.dev, root_netns, orig_ifname);
+               system_link_netns_move(iface->main_dev.dev, netns_fd, orig_ifname);
        }
-
-       close(root_netns);
-       close(netns_fd);
-       _exit(0);
 }
 
 static void
@@ -1343,10 +1314,15 @@ interface_change_config(struct interface *if_old, struct interface *if_new)
        if (if_old->jail)
                if_old->autostart = false;
 
-       if (if_old->jail_ifname)
-               free(if_old->jail_ifname);
+       if (if_old->jail_device)
+               free(if_old->jail_device);
+
+       if_old->jail_device = if_new->jail_device;
+
+       if (if_old->host_device)
+               free(if_old->host_device);
 
-       if_old->jail_ifname = if_new->jail_ifname;
+       if_old->host_device = if_new->host_device;
 
        if_old->device = if_new->device;
        if_old->parent_ifname = if_new->parent_ifname;

diff --git a/interface.h b/interface.h
index 1767bf1dd63c8fd5423f8b6118e05c2da87ebd38..73a907059b8b605f27189b5cfeb6e45b5d40dc1b 100644 (file)
--- a/interface.h
+++ b/interface.h
@@ -109,7 +109,8 @@ struct interface {
        const char *name;
        const char *device;
        char *jail;
-       char *jail_ifname;
+       char *jail_device;
+       char *host_device;
        int netns_fd;
 
        bool available;
@@ -208,7 +209,7 @@ void interface_update_start(struct interface *iface, const bool keep_old);
 void interface_update_complete(struct interface *iface);
 
 void interface_start_pending(void);
-void interface_start_jail(const char *jail, const pid_t netns_pid);
-void interface_stop_jail(const char *jail, const pid_t netns_pid);
+void interface_start_jail(int netns_fd, const char *jail);
+void interface_stop_jail(int netns_fd);
 
 #endif

diff --git a/ubus.c b/ubus.c
index 4770cb686534ae37f230b3067e638ed16373d1f1..a38617928b415c7540338684a1402785d83dd416 100644 (file)
--- a/ubus.c
+++ b/ubus.c
@@ -159,14 +159,12 @@ error:
 
 enum {
        NETNS_UPDOWN_JAIL,
-       NETNS_UPDOWN_PID,
        NETNS_UPDOWN_START,
        __NETNS_UPDOWN_MAX
 };
 
 static const struct blobmsg_policy netns_updown_policy[__NETNS_UPDOWN_MAX] = {
        [NETNS_UPDOWN_JAIL] = { .name = "jail", .type = BLOBMSG_TYPE_STRING },
-       [NETNS_UPDOWN_PID] = { .name = "pid", .type = BLOBMSG_TYPE_INT32 },
        [NETNS_UPDOWN_START] = { .name = "start", .type = BLOBMSG_TYPE_BOOL },
 };
 
@@ -175,23 +173,26 @@ netifd_netns_updown(struct ubus_context *ctx, struct ubus_object *obj,
                  struct ubus_request_data *req, const char *method,
                  struct blob_attr *msg)
 {
+       int target_netns_fd = ubus_request_get_caller_fd(req);
        struct blob_attr *tb[__NETNS_UPDOWN_MAX];
-       char *jail;
-       pid_t netns_pid;
        bool start;
 
-       blobmsg_parse(netns_updown_policy, __NETNS_UPDOWN_MAX, tb, blob_data(msg), blob_len(msg));
-       if (!tb[NETNS_UPDOWN_JAIL] || !tb[NETNS_UPDOWN_PID])
+       if (target_netns_fd < 0)
                return UBUS_STATUS_INVALID_ARGUMENT;
 
+       blobmsg_parse(netns_updown_policy, __NETNS_UPDOWN_MAX, tb, blob_data(msg), blob_len(msg));
+
        start = tb[NETNS_UPDOWN_START] && blobmsg_get_bool(tb[NETNS_UPDOWN_START]);
-       jail = blobmsg_get_string(tb[NETNS_UPDOWN_JAIL]);
-       netns_pid = blobmsg_get_u32(tb[NETNS_UPDOWN_PID]);
 
-       if (start)
-               interface_start_jail(jail, netns_pid);
-       else
-               interface_stop_jail(jail, netns_pid);
+       if (start) {
+               if (!tb[NETNS_UPDOWN_JAIL])
+                       return UBUS_STATUS_INVALID_ARGUMENT;
+
+               interface_start_jail(target_netns_fd, blobmsg_get_string(tb[NETNS_UPDOWN_JAIL]));
+       } else {
+               interface_stop_jail(target_netns_fd);
+       }
+       close(target_netns_fd);
 
        return UBUS_STATUS_OK;
 }
@@ -823,8 +824,8 @@ netifd_dump_status(struct interface *iface)
        if (iface->jail)
                blobmsg_add_string(&b, "jail", iface->jail);
 
-       if (iface->jail_ifname)
-               blobmsg_add_string(&b, "jail_ifname", iface->jail_ifname);
+       if (iface->jail_device)
+               blobmsg_add_string(&b, "jail_device", iface->jail_device);
 
        if (iface->state == IFS_UP) {
                if (iface->updated) {