/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include "fd-util.h" #include "format-util.h" #include "missing_sched.h" #include "namespace-util.h" #include "nsresource.h" #include "process-util.h" #include "varlink.h" static int make_pid_name(char **ret) { char comm[TASK_COMM_LEN]; assert(ret); if (prctl(PR_GET_NAME, comm) < 0) return -errno; /* So the namespace name should be 16 chars at max (because we want that it is usable in usernames, * which have a limit of 31 chars effectively, and the nsresourced service wants to prefix/suffix * some bits). But it also should be unique if we are called multiple times in a row. Hence we take * the "comm" name (which is 15 chars), and suffix it with the UID, possibly overriding the end. */ assert_cc(TASK_COMM_LEN == 15 + 1); char spid[DECIMAL_STR_MAX(pid_t)]; xsprintf(spid, PID_FMT, getpid_cached()); assert(strlen(spid) <= 16); strshorten(comm, 16 - strlen(spid)); _cleanup_free_ char *s = strjoin(comm, spid); if (!s) return -ENOMEM; *ret = TAKE_PTR(s); return 0; } int nsresource_allocate_userns(const char *name, uint64_t size) { _cleanup_(varlink_unrefp) Varlink *vl = NULL; _cleanup_close_ int userns_fd = -EBADF; _cleanup_free_ char *_name = NULL; const char *error_id; int r, userns_fd_idx; /* Allocate a new dynamic user namespace via the userdb registry logic */ if (!name) { r = make_pid_name(&_name); if (r < 0) return r; name = _name; } if (size <= 0 || size > UINT64_C(0x100000000)) /* Note: the server actually only allows allocating 1 or 64K right now */ return -EINVAL; r = varlink_connect_address(&vl, "/run/systemd/io.systemd.NamespaceResource"); if (r < 0) return log_debug_errno(r, "Failed to connect to namespace resource manager: %m"); r = varlink_set_allow_fd_passing_output(vl, true); if (r < 0) return log_debug_errno(r, "Failed to enable varlink fd passing for write: %m"); userns_fd = userns_acquire_empty(); if (userns_fd < 0) return log_debug_errno(userns_fd, "Failed to acquire empty user namespace: %m"); userns_fd_idx = varlink_push_dup_fd(vl, userns_fd); if (userns_fd_idx < 0) return log_debug_errno(userns_fd_idx, "Failed to push userns fd into varlink connection: %m"); JsonVariant *reply = NULL; r = varlink_callb(vl, "io.systemd.NamespaceResource.AllocateUserRange", &reply, &error_id, JSON_BUILD_OBJECT( JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name)), JSON_BUILD_PAIR("size", JSON_BUILD_UNSIGNED(size)), JSON_BUILD_PAIR("userNamespaceFileDescriptor", JSON_BUILD_UNSIGNED(userns_fd_idx)))); if (r < 0) return log_debug_errno(r, "Failed to call AllocateUserRange() varlink call: %m"); if (error_id) return log_debug_errno(varlink_error_to_errno(error_id, reply), "Failed to allocate user namespace with %" PRIu64 " users: %s", size, error_id); return TAKE_FD(userns_fd); } int nsresource_register_userns(const char *name, int userns_fd) { _cleanup_(varlink_unrefp) Varlink *vl = NULL; _cleanup_close_ int _userns_fd = -EBADF; _cleanup_free_ char *_name = NULL; const char *error_id; int r, userns_fd_idx; /* Register the specified user namespace with userbd. */ if (!name) { r = make_pid_name(&_name); if (r < 0) return r; name = _name; } if (userns_fd < 0) { _userns_fd = namespace_open_by_type(NAMESPACE_USER); if (_userns_fd < 0) return -errno; userns_fd = _userns_fd; } r = varlink_connect_address(&vl, "/run/systemd/io.systemd.NamespaceResource"); if (r < 0) return log_debug_errno(r, "Failed to connect to namespace resource manager: %m"); r = varlink_set_allow_fd_passing_output(vl, true); if (r < 0) return log_debug_errno(r, "Failed to enable varlink fd passing for write: %m"); userns_fd_idx = varlink_push_dup_fd(vl, userns_fd); if (userns_fd_idx < 0) return log_debug_errno(userns_fd_idx, "Failed to push userns fd into varlink connection: %m"); JsonVariant *reply = NULL; r = varlink_callb(vl, "io.systemd.NamespaceResource.RegisterUserNamespace", &reply, &error_id, JSON_BUILD_OBJECT( JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name)), JSON_BUILD_PAIR("userNamespaceFileDescriptor", JSON_BUILD_UNSIGNED(userns_fd_idx)))); if (r < 0) return log_debug_errno(r, "Failed to call RegisterUserNamespace() varlink call: %m"); if (error_id) return log_debug_errno(varlink_error_to_errno(error_id, reply), "Failed to register user namespace: %s", error_id); return 0; } int nsresource_add_mount(int userns_fd, int mount_fd) { _cleanup_(varlink_unrefp) Varlink *vl = NULL; _cleanup_close_ int _userns_fd = -EBADF; int r, userns_fd_idx, mount_fd_idx; const char *error_id; assert(mount_fd >= 0); if (userns_fd < 0) { _userns_fd = namespace_open_by_type(NAMESPACE_USER); if (_userns_fd < 0) return _userns_fd; userns_fd = _userns_fd; } r = varlink_connect_address(&vl, "/run/systemd/io.systemd.NamespaceResource"); if (r < 0) return log_error_errno(r, "Failed to connect to namespace resource manager: %m"); r = varlink_set_allow_fd_passing_output(vl, true); if (r < 0) return log_error_errno(r, "Failed to enable varlink fd passing for write: %m"); userns_fd_idx = varlink_push_dup_fd(vl, userns_fd); if (userns_fd_idx < 0) return log_error_errno(userns_fd_idx, "Failed to push userns fd into varlink connection: %m"); mount_fd_idx = varlink_push_dup_fd(vl, mount_fd); if (mount_fd_idx < 0) return log_error_errno(mount_fd_idx, "Failed to push mount fd into varlink connection: %m"); JsonVariant *reply = NULL; r = varlink_callb(vl, "io.systemd.NamespaceResource.AddMountToUserNamespace", &reply, &error_id, JSON_BUILD_OBJECT( JSON_BUILD_PAIR("userNamespaceFileDescriptor", JSON_BUILD_UNSIGNED(userns_fd_idx)), JSON_BUILD_PAIR("mountFileDescriptor", JSON_BUILD_UNSIGNED(mount_fd_idx)))); if (r < 0) return log_error_errno(r, "Failed to call AddMountToUserNamespace() varlink call: %m"); if (streq_ptr(error_id, "io.systemd.NamespaceResource.UserNamespaceNotRegistered")) { log_notice("User namespace has not been allocated via namespace resource registry, not adding mount to registration."); return 0; } if (error_id) return log_error_errno(varlink_error_to_errno(error_id, reply), "Failed to mount image: %s", error_id); return 1; } int nsresource_add_cgroup(int userns_fd, int cgroup_fd) { _cleanup_(varlink_unrefp) Varlink *vl = NULL; _cleanup_close_ int _userns_fd = -EBADF; int r, userns_fd_idx, cgroup_fd_idx; const char *error_id; assert(cgroup_fd >= 0); if (userns_fd < 0) { _userns_fd = namespace_open_by_type(NAMESPACE_USER); if (_userns_fd < 0) return -errno; userns_fd = _userns_fd; } r = varlink_connect_address(&vl, "/run/systemd/io.systemd.NamespaceResource"); if (r < 0) return log_debug_errno(r, "Failed to connect to namespace resource manager: %m"); r = varlink_set_allow_fd_passing_output(vl, true); if (r < 0) return log_debug_errno(r, "Failed to enable varlink fd passing for write: %m"); userns_fd_idx = varlink_push_dup_fd(vl, userns_fd); if (userns_fd_idx < 0) return log_debug_errno(userns_fd_idx, "Failed to push userns fd into varlink connection: %m"); cgroup_fd_idx = varlink_push_dup_fd(vl, cgroup_fd); if (cgroup_fd_idx < 0) return log_debug_errno(userns_fd_idx, "Failed to push cgroup fd into varlink connection: %m"); JsonVariant *reply = NULL; r = varlink_callb(vl, "io.systemd.NamespaceResource.AddControlGroupToUserNamespace", &reply, &error_id, JSON_BUILD_OBJECT( JSON_BUILD_PAIR("userNamespaceFileDescriptor", JSON_BUILD_UNSIGNED(userns_fd_idx)), JSON_BUILD_PAIR("controlGroupFileDescriptor", JSON_BUILD_UNSIGNED(cgroup_fd_idx)))); if (r < 0) return log_debug_errno(r, "Failed to call AddControlGroupToUserNamespace() varlink call: %m"); if (streq_ptr(error_id, "io.systemd.NamespaceResource.UserNamespaceNotRegistered")) { log_notice("User namespace has not been allocated via namespace resource registry, not adding cgroup to registration."); return 0; } if (error_id) return log_debug_errno(varlink_error_to_errno(error_id, reply), "Failed to add cgroup to user namespace: %s", error_id); return 1; } int nsresource_add_netif( int userns_fd, int netns_fd, const char *namespace_ifname, char **ret_host_ifname, char **ret_namespace_ifname) { _cleanup_close_ int _userns_fd = -EBADF, _netns_fd = -EBADF; _cleanup_(varlink_unrefp) Varlink *vl = NULL; int r, userns_fd_idx, netns_fd_idx; const char *error_id; if (userns_fd < 0) { _userns_fd = namespace_open_by_type(NAMESPACE_USER); if (_userns_fd < 0) return -errno; userns_fd = _userns_fd; } if (netns_fd < 0) { _netns_fd = namespace_open_by_type(NAMESPACE_NET); if (_netns_fd < 0) return -errno; netns_fd = _netns_fd; } r = varlink_connect_address(&vl, "/run/systemd/io.systemd.NamespaceResource"); if (r < 0) return log_debug_errno(r, "Failed to connect to namespace resource manager: %m"); r = varlink_set_allow_fd_passing_output(vl, true); if (r < 0) return log_debug_errno(r, "Failed to enable varlink fd passing for write: %m"); userns_fd_idx = varlink_push_dup_fd(vl, userns_fd); if (userns_fd_idx < 0) return log_debug_errno(userns_fd_idx, "Failed to push userns fd into varlink connection: %m"); netns_fd_idx = varlink_push_dup_fd(vl, netns_fd); if (netns_fd_idx < 0) return log_debug_errno(netns_fd_idx, "Failed to push netns fd into varlink connection: %m"); JsonVariant *reply = NULL; r = varlink_callb(vl, "io.systemd.NamespaceResource.AddNetworkToUserNamespace", &reply, &error_id, JSON_BUILD_OBJECT( JSON_BUILD_PAIR("userNamespaceFileDescriptor", JSON_BUILD_UNSIGNED(userns_fd_idx)), JSON_BUILD_PAIR("networkNamespaceFileDescriptor", JSON_BUILD_UNSIGNED(netns_fd_idx)), JSON_BUILD_PAIR("mode", JSON_BUILD_CONST_STRING("veth")), JSON_BUILD_PAIR_CONDITION(namespace_ifname, "namespaceInterfaceName", JSON_BUILD_STRING(namespace_ifname)))); if (r < 0) return log_debug_errno(r, "Failed to call AddNetworkToUserNamespace() varlink call: %m"); if (streq_ptr(error_id, "io.systemd.NamespaceResource.UserNamespaceNotRegistered")) { log_notice("User namespace has not been allocated via namespace resource registry, not adding network to registration."); return 0; } if (error_id) return log_debug_errno(varlink_error_to_errno(error_id, reply), "Failed to add network to user namespace: %s", error_id); _cleanup_free_ char *host_interface_name = NULL, *namespace_interface_name = NULL; r = json_dispatch( reply, (const JsonDispatch[]) { { "hostInterfaceName", JSON_VARIANT_STRING, json_dispatch_string, PTR_TO_SIZE(&host_interface_name) }, { "namespaceInterfaceName", JSON_VARIANT_STRING, json_dispatch_string, PTR_TO_SIZE(&namespace_interface_name) }, }, JSON_ALLOW_EXTENSIONS, /* userdata= */ NULL); if (ret_host_ifname) *ret_host_ifname = TAKE_PTR(host_interface_name); if (ret_namespace_ifname) *ret_namespace_ifname = TAKE_PTR(namespace_interface_name); return 1; }