diff --git a/include/server-unpriv.h b/include/server-unpriv.h new file mode 100644 index 00000000..d8c8eee0 --- /dev/null +++ b/include/server-unpriv.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef LABWC_SERVER_UNPRIV_H +#define LABWC_SERVER_UNPRIV_H + +struct server; +struct wl_client; + +void unpriv_socket_start(struct server *server); +bool is_unpriv_client(const struct wl_client *wl_client); + +#endif /* LABWC_UNPRIV_H */ diff --git a/src/meson.build b/src/meson.build index 391e9cdc..9c0f505c 100644 --- a/src/meson.build +++ b/src/meson.build @@ -19,6 +19,7 @@ labwc_sources = files( 'resistance.c', 'seat.c', 'server.c', + 'server-unpriv.c', 'session-lock.c', 'touch.c', 'theme.c', diff --git a/src/server-unpriv.c b/src/server-unpriv.c new file mode 100644 index 00000000..98549070 --- /dev/null +++ b/src/server-unpriv.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include "common/list.h" +#include "common/mem.h" +#include "labwc.h" +#include "server-unpriv.h" + +static struct unpriv_socket { + char *path; + int listen_fd; + struct wl_event_source *event_source; + struct wl_listener on_display_destroy; + + struct wl_list clients; +} unpriv_socket; + +struct unpriv_client { + struct wl_client *wl_client; + struct wl_listener on_destroy; + + struct wl_list link; +}; + +static void +unpriv_socket_finish(void) +{ + if (unpriv_socket.listen_fd > 0) { + close(unpriv_socket.listen_fd); + unpriv_socket.listen_fd = 0; + } + if (unpriv_socket.event_source) { + wl_event_source_remove(unpriv_socket.event_source); + unpriv_socket.event_source = NULL; + } + if (unpriv_socket.path) { + unlink(unpriv_socket.path); + zfree(unpriv_socket.path); + } +} + +static void +on_unpriv_client_destroy(struct wl_listener *listener, void *data) +{ + struct unpriv_client *client = wl_container_of(listener, client, on_destroy); + wl_list_remove(&client->on_destroy.link); + wl_list_remove(&client->link); + free(client); + wlr_log(WLR_DEBUG, "unpriv client destroyed"); +} + +static int +on_unpriv_socket_connect(int fd, uint32_t mask, void *data) +{ + struct wl_display *display = data; + + if (mask & (WL_EVENT_HANGUP | WL_EVENT_ERROR)) { + wlr_log(WLR_DEBUG, "unpriv socket going down, cleaning up"); + unpriv_socket_finish(); + return 0; + } + + /* FIXME: cloexec / accept4 */ + if (mask & WL_EVENT_READABLE) { + int client_fd = accept(fd, NULL, NULL); + if (client_fd < 0) { + wlr_log(WLR_ERROR, "Failed to accept unpriv client"); + return 0; + }; + + struct unpriv_client *client = znew(*client); + client->wl_client = wl_client_create(display, client_fd); + if (!client->wl_client) { + wlr_log(WLR_ERROR, "Failed to create unpriv client"); + close(client_fd); + free(client); + return 0; + } + + wlr_log(WLR_DEBUG, "Accepted new unpriv client: %i", client_fd); + wl_list_append(&unpriv_socket.clients, &client->link); + client->on_destroy.notify = on_unpriv_client_destroy; + wl_client_add_destroy_listener(client->wl_client, &client->on_destroy); + } + return 0; +} + +static void +on_display_destroy(struct wl_listener *listener, void *data) +{ + wl_list_remove(&unpriv_socket.on_display_destroy.link); + unpriv_socket_finish(); +} + +void +unpriv_socket_start(struct server *server) +{ + wl_list_init(&unpriv_socket.clients); + + /* FIXME: lockfile, CLOEXEC fallback */ + + struct sockaddr_un addr = { .sun_family = AF_LOCAL }; + int addr_size = snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", + getenv("XDG_RUNTIME_DIR"), "wayland-unpriv") + 1; + + if (addr_size > (int)sizeof(addr.sun_path)) { + addr.sun_path[sizeof(addr.sun_path) - 1] = '\0'; + wlr_log(WLR_ERROR, "Truncated unpriv socket path to %s", addr.sun_path); + } + + /* + * TODO: use close-on-exec fallback like + * https://gitlab.freedesktop.org/wayland/wayland/-/blob/main/src/wayland-os.c#L74 + */ + int fd = socket(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (fd < 0) { + wlr_log(WLR_ERROR, "Failed to create unpriv socket"); + return; + } + unpriv_socket.listen_fd = fd; + wlr_log(WLR_ERROR, "Got unpriv fd: %i", fd); + + /* TODO: why offsetof(addr, sun_path) + strlen(addr.sun_path) ? */ + if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + wlr_log(WLR_ERROR, "Failed to bind unpriv socket"); + goto error; + } + unpriv_socket.path = xstrdup(addr.sun_path); + + /* A Backlog of 16 seems more than enough for a unprivileged socket */ + if (listen(fd, 16) < 0) { + wlr_log(WLR_ERROR, "Failed to listen in unpriv socket"); + goto error; + } + + unpriv_socket.event_source = wl_event_loop_add_fd( + server->wl_event_loop, fd, WL_EVENT_READABLE, + on_unpriv_socket_connect, server->wl_display); + if (!unpriv_socket.event_source) { + wlr_log(WLR_ERROR, "Failed to add unpriv socket to loop"); + goto error; + } + + unpriv_socket.on_display_destroy.notify = on_display_destroy; + wl_display_add_destroy_listener(server->wl_display, &unpriv_socket.on_display_destroy); + + wlr_log(WLR_INFO, "Unprivileged socket opened at '%s'", addr.sun_path); + return; + +error: + unpriv_socket_finish(); +} + +bool +is_unpriv_client(const struct wl_client *wl_client) +{ + if (unpriv_socket.listen_fd <= 0) { + /* TODO: we could return true here to block the protocols for the main socket */ + return false; + } + struct unpriv_client *unpriv_client; + wl_list_for_each(unpriv_client, &unpriv_socket.clients, link) { + if (wl_client == unpriv_client->wl_client) { + return true; + } + } + return false; +} diff --git a/src/server.c b/src/server.c index 620c7fb9..63a7bf8c 100644 --- a/src/server.c +++ b/src/server.c @@ -24,6 +24,7 @@ #include "layers.h" #include "menu/menu.h" #include "regions.h" +#include "server-unpriv.h" #include "theme.h" #include "view.h" #include "workspaces.h" @@ -180,11 +181,14 @@ server_global_filter(const struct wl_client *client, const struct wl_global *glo } } #endif - struct blocked_protocol *proto; - wl_list_for_each(proto, &rc.blocked_protocols, link) { - if (!strcmp(iface->name, proto->interface_name)) { - wlr_log(WLR_INFO, "blocking protocol %s", proto->interface_name); - return false; + if (is_unpriv_client(client)) { + struct blocked_protocol *proto; + wl_list_for_each(proto, &rc.blocked_protocols, link) { + if (!strcmp(iface->name, proto->interface_name)) { + wlr_log(WLR_INFO, "blocking protocol %s", + proto->interface_name); + return false; + } } } @@ -485,6 +489,10 @@ server_start(struct server *server) } else { wlr_log(WLR_DEBUG, "WAYLAND_DISPLAY=%s", socket); } + + if (!wl_list_empty(&rc.blocked_protocols)) { + unpriv_socket_start(server); + } } void