]> git.proxmox.com Git - mirror_lxc.git/blobdiff - src/lxc/start.c
start: unify and simplify network creation
[mirror_lxc.git] / src / lxc / start.c
index 89262c736804565be132929a8e321881f0bc33e3..335f6d6fc3624c3a57c6bd6129ec32bc87f4a4f2 100644 (file)
@@ -97,7 +97,7 @@ static void lxc_destroy_container_on_signal(struct lxc_handler *handler,
 
 static void print_top_failing_dir(const char *path)
 {
-       __do_free char *copy;
+       __do_free char *copy = NULL;
        int ret;
        char *e, *p, saved;
 
@@ -406,14 +406,26 @@ static int signal_handler(int fd, uint32_t events, void *data,
        }
 
        if (siginfo.ssi_signo == SIGHUP) {
-               kill(hdlr->pid, SIGTERM);
+               if (hdlr->pidfd >= 0)
+                       lxc_raw_pidfd_send_signal(hdlr->pidfd, SIGTERM, NULL, 0);
+               else if (hdlr->proc_pidfd >= 0)
+                       lxc_raw_pidfd_send_signal(hdlr->proc_pidfd, SIGTERM, NULL, 0);
+               else
+                       kill(hdlr->pid, SIGTERM);
                INFO("Killing %d since terminal hung up", hdlr->pid);
                return hdlr->init_died ? LXC_MAINLOOP_CLOSE
                                       : LXC_MAINLOOP_CONTINUE;
        }
 
        if (siginfo.ssi_signo != SIGCHLD) {
-               kill(hdlr->pid, siginfo.ssi_signo);
+               if (hdlr->pidfd >= 0)
+                       lxc_raw_pidfd_send_signal(hdlr->pidfd,
+                                                 siginfo.ssi_signo, NULL, 0);
+               else if (hdlr->proc_pidfd >= 0)
+                       lxc_raw_pidfd_send_signal(hdlr->proc_pidfd,
+                                                 siginfo.ssi_signo, NULL, 0);
+               else
+                       kill(hdlr->pid, siginfo.ssi_signo);
                INFO("Forwarded signal %d to pid %d", siginfo.ssi_signo, hdlr->pid);
                return hdlr->init_died ? LXC_MAINLOOP_CLOSE
                                       : LXC_MAINLOOP_CONTINUE;
@@ -452,7 +464,6 @@ int lxc_serve_state_clients(const char *name, struct lxc_handler *handler,
        size_t retlen;
        ssize_t ret;
        struct lxc_list *cur, *next;
-       struct lxc_state_client *client;
        struct lxc_msg msg = {.type = lxc_msg_state, .value = state};
 
        if (state == THAWED)
@@ -472,7 +483,7 @@ int lxc_serve_state_clients(const char *name, struct lxc_handler *handler,
                return -E2BIG;
 
        lxc_list_for_each_safe(cur, &handler->conf->state_clients, next) {
-               client = cur->elem;
+               struct lxc_state_client *client = cur->elem;
 
                if (client->states[state] == 0) {
                        TRACE("State %s not registered for state client %d",
@@ -592,6 +603,12 @@ int lxc_poll(const char *name, struct lxc_handler *handler)
                goto out_mainloop_console;
        }
 
+       ret = lxc_seccomp_setup_proxy(&handler->conf->seccomp, &descr, handler);
+       if (ret < 0) {
+               ERROR("Failed to setup seccomp proxy");
+               goto out_mainloop_console;
+       }
+
        if (has_console) {
                struct lxc_terminal *console = &handler->conf->console;
 
@@ -653,6 +670,10 @@ void lxc_zero_handler(struct lxc_handler *handler)
 
        handler->pinfd = -1;
 
+       handler->pidfd = -EBADF;
+
+       handler->proc_pidfd = -EBADF;
+
        handler->sigfd = -1;
 
        for (i = 0; i < LXC_NS_MAX; i++)
@@ -673,6 +694,12 @@ void lxc_free_handler(struct lxc_handler *handler)
        if (handler->pinfd >= 0)
                close(handler->pinfd);
 
+       if (handler->pidfd >= 0)
+               close(handler->pidfd);
+
+       if (handler->proc_pidfd >= 0)
+               close(handler->proc_pidfd);
+
        if (handler->sigfd >= 0)
                close(handler->sigfd);
 
@@ -717,6 +744,8 @@ struct lxc_handler *lxc_init_handler(const char *name, struct lxc_conf *conf,
        handler->conf = conf;
        handler->lxcpath = lxcpath;
        handler->pinfd = -1;
+       handler->pidfd = -EBADF;
+       handler->proc_pidfd = -EBADF;
        handler->sigfd = -EBADF;
        handler->init_died = false;
        handler->state_socket_pair[0] = handler->state_socket_pair[1] = -1;
@@ -1027,6 +1056,9 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
                lxc_set_state(name, handler, STOPPED);
        }
 
+       /* Avoid lingering namespace references. */
+       lxc_put_nsfds(handler);
+
        ret = run_lxc_hooks(name, "post-stop", handler->conf, NULL);
        if (ret < 0) {
                ERROR("Failed to run lxc.hook.post-stop for container \"%s\"", name);
@@ -1075,23 +1107,30 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
 
 void lxc_abort(const char *name, struct lxc_handler *handler)
 {
-       int ret, status;
+       int ret = 0;
+       int status;
 
        lxc_set_state(name, handler, ABORTING);
 
-       if (handler->pid > 0) {
+       if (handler->pidfd > 0)
+               ret = lxc_raw_pidfd_send_signal(handler->pidfd, SIGKILL, NULL, 0);
+       else if (handler->proc_pidfd > 0)
+               ret = lxc_raw_pidfd_send_signal(handler->proc_pidfd, SIGKILL, NULL, 0);
+       else if (handler->pid > 0)
                ret = kill(handler->pid, SIGKILL);
-               if (ret < 0)
-                       SYSERROR("Failed to send SIGKILL to %d", handler->pid);
-       }
+       if (ret < 0)
+               SYSERROR("Failed to send SIGKILL to %d", handler->pid);
 
-       while ((ret = waitpid(-1, &status, 0)) > 0) {
-               ;
-       }
+       do {
+               ret = waitpid(-1, &status, 0);
+       } while (ret > 0);
 }
 
 static int do_start(void *data)
 {
+       struct lxc_handler *handler = data;
+       ATTR_UNUSED __do_close_prot_errno int data_sock0 = handler->data_sock[0],
+                                             data_sock1 = handler->data_sock[1];
        int ret;
        char path[PATH_MAX];
        uid_t new_uid;
@@ -1100,7 +1139,6 @@ static int do_start(void *data)
        uid_t nsuid = 0;
        gid_t nsgid = 0;
        int devnull_fd = -1;
-       struct lxc_handler *handler = data;
 
        lxc_sync_fini_parent(handler);
 
@@ -1110,7 +1148,7 @@ static int do_start(void *data)
         * exit before we set the pdeath signal leading to a unsupervized
         * container.
         */
-       ret = lxc_set_death_signal(SIGKILL, 0);
+       ret = lxc_set_death_signal(SIGKILL, handler->monitor_pid);
        if (ret < 0) {
                SYSERROR("Failed to set PR_SET_PDEATHSIG to SIGKILL");
                goto out_warn_father;
@@ -1156,10 +1194,12 @@ static int do_start(void *data)
        if (ret < 0)
                goto out_error;
 
-       ret = lxc_network_recv_veth_names_from_parent(handler);
-       if (ret < 0) {
-               ERROR("Failed to receive veth names from parent");
-               goto out_warn_father;
+       if (handler->ns_clone_flags & CLONE_NEWNET) {
+               ret = lxc_network_recv_veth_names_from_parent(handler);
+               if (ret < 0) {
+                       ERROR("Failed to receive veth names from parent");
+                       goto out_warn_father;
+               }
        }
 
        /* If we are in a new user namespace, become root there to have
@@ -1188,7 +1228,7 @@ static int do_start(void *data)
                        goto out_warn_father;
 
                /* set{g,u}id() clears deathsignal */
-               ret = lxc_set_death_signal(SIGKILL, 0);
+               ret = lxc_set_death_signal(SIGKILL, handler->monitor_pid);
                if (ret < 0) {
                        SYSERROR("Failed to set PR_SET_PDEATHSIG to SIGKILL");
                        goto out_warn_father;
@@ -1276,8 +1316,6 @@ static int do_start(void *data)
 
        /* Setup the container, ip, names, utsname, ... */
        ret = lxc_setup(handler);
-       close(handler->data_sock[1]);
-       close(handler->data_sock[0]);
        if (ret < 0) {
                ERROR("Failed to setup container \"%s\"", handler->name);
                goto out_warn_father;
@@ -1328,6 +1366,12 @@ static int do_start(void *data)
        if (ret < 0)
                goto out_warn_father;
 
+       ret = lxc_seccomp_send_notifier_fd(&handler->conf->seccomp, data_sock0);
+       if (ret < 0) {
+               SYSERROR("Failed to send seccomp notify fd to parent");
+               goto out_warn_father;
+       }
+
        ret = run_lxc_hooks(handler->name, "start", handler->conf, NULL);
        if (ret < 0) {
                ERROR("Failed to run lxc.hook.start for container \"%s\"",
@@ -1436,7 +1480,7 @@ static int do_start(void *data)
        }
 
        if (handler->conf->monitor_signal_pdeath != SIGKILL) {
-               ret = lxc_set_death_signal(handler->conf->monitor_signal_pdeath, 0);
+               ret = lxc_set_death_signal(handler->conf->monitor_signal_pdeath, handler->monitor_pid);
                if (ret < 0) {
                        SYSERROR("Failed to set PR_SET_PDEATHSIG to %d",
                                 handler->conf->monitor_signal_pdeath);
@@ -1574,13 +1618,35 @@ static inline int do_share_ns(void *arg)
 
        flags = handler->ns_on_clone_flags;
        flags |= CLONE_PARENT;
-       handler->pid = lxc_raw_clone_cb(do_start, handler, flags);
+       handler->pid = lxc_raw_clone_cb(do_start, handler, CLONE_PIDFD | flags,
+                                       &handler->pidfd);
        if (handler->pid < 0)
                return -1;
 
        return 0;
 }
 
+static int proc_pidfd_open(pid_t pid)
+{
+       __do_close_prot_errno int proc_pidfd = -EBADF;
+       char path[100];
+
+       snprintf(path, sizeof(path), "/proc/%d", pid);
+       proc_pidfd = open(path, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+       if (proc_pidfd < 0) {
+               SYSERROR("Failed to open %s", path);
+               return -1;
+       }
+
+       /* Test whether we can send signals. */
+       if (lxc_raw_pidfd_send_signal(proc_pidfd, 0, NULL, 0)) {
+               SYSERROR("Failed to send signal through pidfd");
+               return -1;
+       }
+
+       return move_fd(proc_pidfd);
+}
+
 /* lxc_spawn() performs crucial setup tasks and clone()s the new process which
  * exec()s the requested container binary.
  * Note that lxc_spawn() runs in the parent namespaces. Any operations performed
@@ -1590,6 +1656,7 @@ static inline int do_share_ns(void *arg)
  */
 static int lxc_spawn(struct lxc_handler *handler)
 {
+       __do_close_prot_errno int data_sock0 = -EBADF, data_sock1 = -EBADF;
        int i, ret;
        char pidstr[20];
        bool wants_to_map_ids;
@@ -1622,36 +1689,13 @@ static int lxc_spawn(struct lxc_handler *handler)
                         handler->data_sock);
        if (ret < 0)
                goto out_sync_fini;
+       data_sock0 = handler->data_sock[0];
+       data_sock1 = handler->data_sock[1];
 
        ret = resolve_clone_flags(handler);
        if (ret < 0)
                goto out_sync_fini;
 
-       if (handler->ns_clone_flags & CLONE_NEWNET) {
-               if (!lxc_list_empty(&conf->network)) {
-
-                       /* Find gateway addresses from the link device, which is
-                        * no longer accessible inside the container. Do this
-                        * before creating network interfaces, since goto
-                        * out_delete_net does not work before lxc_clone.
-                        */
-                       ret = lxc_find_gateway_addresses(handler);
-                       if (ret < 0) {
-                               ERROR("Failed to find gateway addresses");
-                               goto out_sync_fini;
-                       }
-
-                       /* That should be done before the clone because we will
-                        * fill the netdev index and use them in the child.
-                        */
-                       ret = lxc_create_network_priv(handler);
-                       if (ret < 0) {
-                               ERROR("Failed to create the network");
-                               goto out_delete_net;
-                       }
-               }
-       }
-
        if (!cgroup_ops->payload_create(cgroup_ops, handler)) {
                ERROR("Failed creating cgroups");
                goto out_delete_net;
@@ -1684,7 +1728,7 @@ static int lxc_spawn(struct lxc_handler *handler)
                pid_t attacher_pid;
 
                attacher_pid = lxc_clone(do_share_ns, handler,
-                                        CLONE_VFORK | CLONE_VM | CLONE_FILES);
+                                        CLONE_VFORK | CLONE_VM | CLONE_FILES, NULL);
                if (attacher_pid < 0) {
                        SYSERROR(LXC_CLONE_ERROR);
                        goto out_delete_net;
@@ -1697,7 +1741,8 @@ static int lxc_spawn(struct lxc_handler *handler)
                }
        } else {
                handler->pid = lxc_raw_clone_cb(do_start, handler,
-                                               handler->ns_on_clone_flags);
+                                               CLONE_PIDFD | handler->ns_on_clone_flags,
+                                               &handler->pidfd);
        }
        if (handler->pid < 0) {
                SYSERROR(LXC_CLONE_ERROR);
@@ -1705,6 +1750,12 @@ static int lxc_spawn(struct lxc_handler *handler)
        }
        TRACE("Cloned child process %d", handler->pid);
 
+       if (handler->pidfd < 0) {
+               handler->proc_pidfd = proc_pidfd_open(handler->pid);
+               if (handler->proc_pidfd < 0 && (errno != ENOSYS))
+                       goto out_delete_net;
+       }
+
        for (i = 0; i < LXC_NS_MAX; i++)
                if (handler->ns_on_clone_flags & ns_info[i].clone_flag)
                        INFO("Cloned %s", ns_info[i].flag_name);
@@ -1752,49 +1803,40 @@ static int lxc_spawn(struct lxc_handler *handler)
        if (!cgroup_ops->chown(cgroup_ops, handler->conf))
                goto out_delete_net;
 
-       /* Now we're ready to preserve the network namespace */
-       ret = lxc_try_preserve_ns(handler->pid, "net");
-       if (ret < 0) {
-               if (ret != -EOPNOTSUPP) {
-                       SYSERROR("Failed to preserve net namespace");
-                       goto out_delete_net;
+       /* If not done yet, we're now ready to preserve the network namespace */
+       if (handler->nsfd[LXC_NS_NET] < 0) {
+               ret = lxc_try_preserve_ns(handler->pid, "net");
+               if (ret < 0) {
+                       if (ret != -EOPNOTSUPP) {
+                               SYSERROR("Failed to preserve net namespace");
+                               goto out_delete_net;
+                       }
+               } else {
+                       handler->nsfd[LXC_NS_NET] = ret;
+                       DEBUG("Preserved net namespace via fd %d", ret);
                }
-       } else {
-               handler->nsfd[LXC_NS_NET] = ret;
-               DEBUG("Preserved net namespace via fd %d", ret);
-
-               ret = lxc_netns_set_nsid(handler->nsfd[LXC_NS_NET]);
-               if (ret < 0)
-                       SYSWARN("Failed to allocate new network namespace id");
-               else
-                       TRACE("Allocated new network namespace id");
        }
+       ret = lxc_netns_set_nsid(handler->nsfd[LXC_NS_NET]);
+       if (ret < 0)
+               SYSWARN("Failed to allocate new network namespace id");
+       else
+               TRACE("Allocated new network namespace id");
 
        /* Create the network configuration. */
        if (handler->ns_clone_flags & CLONE_NEWNET) {
-               ret = lxc_network_move_created_netdev_priv(handler->lxcpath,
-                                                          handler->name,
-                                                          &conf->network,
-                                                          handler->pid);
+               ret = lxc_create_network(handler);
                if (ret < 0) {
-                       ERROR("Failed to create the configured network");
+                       ERROR("Failed to create the network");
                        goto out_delete_net;
                }
 
-               ret = lxc_create_network_unpriv(handler->lxcpath, handler->name,
-                                               &conf->network, handler->pid, conf->hooks_version);
+               ret = lxc_network_send_veth_names_to_child(handler);
                if (ret < 0) {
-                       ERROR("Failed to create the configured network");
+                       ERROR("Failed to send veth names to child");
                        goto out_delete_net;
                }
        }
 
-       ret = lxc_network_send_veth_names_to_child(handler);
-       if (ret < 0) {
-               ERROR("Failed to send veth names to child");
-               goto out_delete_net;
-       }
-
        if (!lxc_list_empty(&conf->procs)) {
                ret = setup_proc_filesystem(&conf->procs, handler->pid);
                if (ret < 0)
@@ -1865,11 +1907,12 @@ static int lxc_spawn(struct lxc_handler *handler)
        if (ret < 0)
                goto out_delete_net;
 
-       ret = lxc_network_recv_name_and_ifindex_from_child(handler);
-       if (ret < 0) {
-               ERROR("Failed to receive names and ifindices for network "
-                     "devices from child");
-               goto out_delete_net;
+       if (handler->ns_clone_flags & CLONE_NEWNET) {
+               ret = lxc_network_recv_name_and_ifindex_from_child(handler);
+               if (ret < 0) {
+                       ERROR("Failed to receive names and ifindices for network devices from child");
+                       goto out_delete_net;
+               }
        }
 
        /* Now all networks are created, network devices are moved into place,
@@ -1886,6 +1929,12 @@ static int lxc_spawn(struct lxc_handler *handler)
                goto out_delete_net;
        }
 
+       ret = lxc_seccomp_recv_notifier_fd(&handler->conf->seccomp, data_sock1);
+       if (ret < 0) {
+               SYSERROR("Failed to receive seccomp notify fd from child");
+               goto out_delete_net;
+       }
+
        ret = handler->ops->post_start(handler, handler->data);
        if (ret < 0)
                goto out_abort;
@@ -1928,7 +1977,7 @@ int __lxc_start(const char *name, struct lxc_handler *handler,
        ret = lxc_init(name, handler);
        if (ret < 0) {
                ERROR("Failed to initialize container \"%s\"", name);
-               return -1;
+               goto out_fini_nonet;
        }
        handler->ops = ops;
        handler->data = data;
@@ -1978,11 +2027,6 @@ int __lxc_start(const char *name, struct lxc_handler *handler,
                ERROR("Failed to spawn container \"%s\"", name);
                goto out_detach_blockdev;
        }
-       /* close parent side of data socket */
-       close(handler->data_sock[0]);
-       handler->data_sock[0] = -1;
-       close(handler->data_sock[1]);
-       handler->data_sock[1] = -1;
 
        handler->conf->reboot = REBOOT_NONE;