diff --git a/CMake/FindLibcap.cmake b/CMake/FindLibcap.cmake new file mode 100644 index 00000000..b34e5e37 --- /dev/null +++ b/CMake/FindLibcap.cmake @@ -0,0 +1,56 @@ +#.rst: +# FindLibcap +# ------- +# +# Find Libcap library +# +# Try to find Libcap library. The following values are defined +# +# :: +# +# Libcap_FOUND - True if Libcap is available +# Libcap_INCLUDE_DIRS - Include directories for Libcap +# Libcap_LIBRARIES - List of libraries for Libcap +# Libcap_DEFINITIONS - List of definitions for Libcap +# +# and also the following more fine grained variables +# +# :: +# +# Libcap_VERSION +# Libcap_VERSION_MAJOR +# Libcap_VERSION_MINOR +# +#============================================================================= +# Copyright (c) 2017 Jerzi Kaminsky +# +# Distributed under the OSI-approved BSD License (the "License"); +# +# This software is distributed WITHOUT ANY WARRANTY; without even the +# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +# See the License for more information. +#============================================================================= + +include(FeatureSummary) +set_package_properties(Libcap PROPERTIES + URL "https://www.kernel.org/pub/linux/libs/security/linux-privs/libcap2" + DESCRIPTION "Library for getting and setting POSIX.1e capabilities") + +find_package(PkgConfig) +pkg_check_modules(PC_CAP QUIET Libcap) +find_library(Libcap_LIBRARIES NAMES cap HINTS ${PC_CAP_LIBRARY_DIRS}) +find_path(Libcap_INCLUDE_DIRS sys/capability.h HINTS ${PC_CAP_INCLUDE_DIRS}) + +set(Libcap_VERSION ${PC_CAP_VERSION}) +string(REPLACE "." ";" VERSION_LIST "${PC_CAP_VERSION}") + +LIST(LENGTH VERSION_LIST n) +if (n EQUAL 2) + list(GET VERSION_LIST 0 Libcap_VERSION_MAJOR) + list(GET VERSION_LIST 1 Libcap_VERSION_MINOR) +endif () + +include(FindPackageHandleStandardArgs) +find_package_handle_standard_args(Libcap DEFAULT_MSG Libcap_INCLUDE_DIRS Libcap_LIBRARIES) +mark_as_advanced(Libcap_INCLUDE_DIRS Libcap_LIBRARIES Libcap_DEFINITIONS + Libcap_VERSION Libcap_VERSION_MAJOR Libcap_VERSION_MICRO Libcap_VERSION_MINOR) diff --git a/CMakeLists.txt b/CMakeLists.txt index b15882ce..d1276f8b 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -50,6 +50,7 @@ find_package(GBM REQUIRED) find_package(LibInput REQUIRED) find_package(XKBCommon REQUIRED) find_package(Udev REQUIRED) +find_package(Libcap) find_package(Systemd) include(Wayland) diff --git a/README.md b/README.md index 75d191d4..4dcfed0e 100644 --- a/README.md +++ b/README.md @@ -18,6 +18,7 @@ Install dependencies: * libinput * udev * systemd (optional, for logind support) +* libcap (optional, for capability support) * asciidoc (optional, for man pages) Run these commands: diff --git a/examples/shared.c b/examples/shared.c index fbb6c559..6d225a85 100644 --- a/examples/shared.c +++ b/examples/shared.c @@ -466,6 +466,7 @@ void compositor_init(struct compositor_state *state) { struct wlr_backend *wlr = wlr_backend_autocreate( state->display, state->session); if (!wlr) { + wlr_session_finish(state->session); exit(1); } wl_signal_add(&wlr->events.input_add, &state->input_add); @@ -477,10 +478,19 @@ void compositor_init(struct compositor_state *state) { clock_gettime(CLOCK_MONOTONIC, &state->last_frame); const char *socket = wl_display_add_socket_auto(state->display); + if (!socket) { + wlr_log_errno(L_ERROR, "Unable to open wayland socket"); + wlr_backend_destroy(wlr); + wlr_session_finish(state->session); + exit(1); + } + wlr_log(L_INFO, "Running compositor on wayland display '%s'", socket); setenv("_WAYLAND_DISPLAY", socket, true); if (!wlr_backend_init(state->backend)) { wlr_log(L_ERROR, "Failed to initialize backend"); + wlr_backend_destroy(wlr); + wlr_session_finish(state->session); exit(1); } } diff --git a/include/session/direct-ipc.h b/include/session/direct-ipc.h new file mode 100644 index 00000000..96504f04 --- /dev/null +++ b/include/session/direct-ipc.h @@ -0,0 +1,12 @@ +#ifndef SESSION_DIRECT_IPC +#define SESSION_DIRECT_IPC + +#include + +int direct_ipc_open(int sock, const char *path); +void direct_ipc_setmaster(int sock, int fd); +void direct_ipc_dropmaster(int sock, int fd); +void direct_ipc_finish(int sock, pid_t pid); +int direct_ipc_start(pid_t *pid_out); + +#endif diff --git a/include/wlr/session.h b/include/wlr/session.h index 4a5b2174..7961e620 100644 --- a/include/wlr/session.h +++ b/include/wlr/session.h @@ -9,16 +9,57 @@ struct session_impl; struct wlr_session { const struct session_impl *impl; - - bool active; + /* + * Signal for when the session becomes active/inactive. + * It's called when we swap virtual terminal. + */ struct wl_signal session_signal; + bool active; + + int drm_fd; + unsigned vtnr; + char seat[8]; }; +/* + * Opens a session, taking control of the current virtual terminal. + * This should not be called if another program is already in control + * of the terminal (Xorg, another Wayland compositor, etc.). + * + * If logind support is not enabled, you must have CAP_SYS_ADMIN or be root. + * It is safe to drop priviledges after this is called. + * + * Returns NULL on error. + */ struct wlr_session *wlr_session_start(struct wl_display *disp); + +/* + * Closes a previously opened session and restores the virtual terminal. + * You should call wlr_session_close_file on each files you opened + * with wlr_session_open_file before you call this. + */ void wlr_session_finish(struct wlr_session *session); -int wlr_session_open_file(struct wlr_session *restrict session, - const char *restrict path); + +/* + * Opens the file at path. + * This can only be used to open DRM or evdev (input) devices. + * + * When the session becomes inactive: + * - DRM files lose their DRM master status + * - evdev files become invalid and should be closed + * + * Returns -errno on error. + */ +int wlr_session_open_file(struct wlr_session *session, const char *path); + +/* + * Closes a file previously opened with wlr_session_open_file. + */ void wlr_session_close_file(struct wlr_session *session, int fd); -bool wlr_session_change_vt(struct wlr_session *session, int vt); + +/* + * Changes the virtual terminal. + */ +bool wlr_session_change_vt(struct wlr_session *session, unsigned vt); #endif diff --git a/include/wlr/session/interface.h b/include/wlr/session/interface.h index f75acfa4..4938110d 100644 --- a/include/wlr/session/interface.h +++ b/include/wlr/session/interface.h @@ -6,10 +6,9 @@ struct session_impl { struct wlr_session *(*start)(struct wl_display *disp); void (*finish)(struct wlr_session *session); - int (*open)(struct wlr_session *restrict session, - const char *restrict path); + int (*open)(struct wlr_session *session, const char *path); void (*close)(struct wlr_session *session, int fd); - bool (*change_vt)(struct wlr_session *session, int vt); + bool (*change_vt)(struct wlr_session *session, unsigned vt); }; #endif diff --git a/session/CMakeLists.txt b/session/CMakeLists.txt index 23077c12..bacd412f 100644 --- a/session/CMakeLists.txt +++ b/session/CMakeLists.txt @@ -1,10 +1,12 @@ include_directories( - ${WAYLAND_INCLUDE_DIR} + ${WAYLAND_INCLUDE_DIR} + ${DRM_INCLUDE_DIRS} ) set(sources session.c direct.c + direct-ipc.c ) set(libs @@ -21,5 +23,13 @@ if (SYSTEMD_FOUND) list(APPEND libs ${SYSTEMD_LIBRARIES}) endif () +if (Libcap_FOUND) + add_definitions(${Libcap_DEFINITIONS}) + include_directories(${Libcap_INCLUDE_DIRS}) + + add_definitions(-DHAS_LIBCAP) + list(APPEND libs ${Libcap_LIBRARIES}) +endif () + add_library(wlr-session ${sources}) target_link_libraries(wlr-session ${libs}) diff --git a/session/direct-ipc.c b/session/direct-ipc.c new file mode 100644 index 00000000..fbbde02a --- /dev/null +++ b/session/direct-ipc.c @@ -0,0 +1,235 @@ +#define _POSIX_C_SOURCE 200809L +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "session/direct-ipc.h" + +enum { DRM_MAJOR = 226 }; + +#ifdef HAS_LIBCAP +#include + +static bool have_permissions(void) { + cap_t cap = cap_get_proc(); + cap_flag_value_t val; + + if (!cap || cap_get_flag(cap, CAP_SYS_ADMIN, CAP_PERMITTED, &val) || val != CAP_SET) { + wlr_log(L_ERROR, "Do not have CAP_SYS_ADMIN; cannot become DRM master"); + cap_free(cap); + return false; + } + + cap_free(cap); + return true; +} +#else +static bool have_permissions(void) { + if (geteuid() != 0) { + wlr_log(L_ERROR, "Do not have root privileges; cannot become DRM master"); + return false; + } + + return true; +} +#endif + +static void send_msg(int sock, int fd, void *buf, size_t buf_len) { + char control[CMSG_SPACE(sizeof(fd))] = {0}; + struct iovec iovec = { .iov_base = buf, .iov_len = buf_len }; + struct msghdr msghdr = {0}; + + if (buf) { + msghdr.msg_iov = &iovec; + msghdr.msg_iovlen = 1; + } + + if (fd >= 0) { + msghdr.msg_control = &control; + msghdr.msg_controllen = sizeof(control); + + struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msghdr); + *cmsg = (struct cmsghdr) { + .cmsg_level = SOL_SOCKET, + .cmsg_type = SCM_RIGHTS, + .cmsg_len = CMSG_LEN(sizeof(fd)), + }; + *(int *)CMSG_DATA(cmsg) = fd; + } + + ssize_t ret; + do { + ret = sendmsg(sock, &msghdr, 0); + } while (ret < 0 && errno == EINTR); +} + +static ssize_t recv_msg(int sock, int *fd_out, void *buf, size_t buf_len) { + char control[CMSG_SPACE(sizeof(*fd_out))] = {0}; + struct iovec iovec = { .iov_base = buf, .iov_len = buf_len }; + struct msghdr msghdr = {0}; + + if (buf) { + msghdr.msg_iov = &iovec; + msghdr.msg_iovlen = 1; + } + + if (fd_out) { + msghdr.msg_control = &control; + msghdr.msg_controllen = sizeof(control); + } + + ssize_t ret; + do { + ret = recvmsg(sock, &msghdr, MSG_CMSG_CLOEXEC); + } while (ret < 0 && errno == EINTR); + + if (fd_out) { + struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msghdr); + *fd_out = cmsg ? *(int *)CMSG_DATA(cmsg) : -1; + } + + return ret; +} + +enum msg_type { + MSG_OPEN, + MSG_SETMASTER, + MSG_DROPMASTER, + MSG_END, +}; + +struct msg { + enum msg_type type; + char path[256]; +}; + +static void communicate(int sock) { + struct msg msg; + int drm_fd = -1; + bool running = true; + + while (running && recv_msg(sock, &drm_fd, &msg, sizeof(msg)) >= 0) { + switch (msg.type) { + case MSG_OPEN: + errno = 0; + + // These are the same flags that logind opens files with + int fd = open(msg.path, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); + int ret = errno; + if (fd == -1) { + goto error; + } + + struct stat st; + if (fstat(fd, &st) < 0) { + ret = errno; + goto error; + } + + uint32_t maj = major(st.st_rdev); + if (maj != INPUT_MAJOR && maj != DRM_MAJOR) { + ret = ENOTSUP; + goto error; + } + + if (maj == DRM_MAJOR && drmSetMaster(fd)) { + ret = errno; + } +error: + send_msg(sock, ret ? -1 : fd, &ret, sizeof(ret)); + close(fd); + + break; + + case MSG_SETMASTER: + drmSetMaster(drm_fd); + close(drm_fd); + send_msg(sock, -1, NULL, 0); + break; + + case MSG_DROPMASTER: + drmDropMaster(drm_fd); + close(drm_fd); + send_msg(sock, -1, NULL, 0); + break; + + case MSG_END: + running = false; + send_msg(sock, -1, NULL, 0); + break; + } + } + + close(sock); +} + +int direct_ipc_open(int sock, const char *path) { + struct msg msg = { .type = MSG_OPEN }; + snprintf(msg.path, sizeof(msg.path), "%s", path); + + send_msg(sock, -1, &msg, sizeof(msg)); + + int fd, err; + recv_msg(sock, &fd, &err, sizeof(err)); + + return err ? -err : fd; +} + +void direct_ipc_setmaster(int sock, int fd) { + struct msg msg = { .type = MSG_SETMASTER }; + + send_msg(sock, fd, &msg, sizeof(msg)); + recv_msg(sock, NULL, NULL, 0); +} + +void direct_ipc_dropmaster(int sock, int fd) { + struct msg msg = { .type = MSG_DROPMASTER }; + + send_msg(sock, fd, &msg, sizeof(msg)); + recv_msg(sock, NULL, NULL, 0); +} + +void direct_ipc_finish(int sock, pid_t pid) { + struct msg msg = { .type = MSG_END }; + + send_msg(sock, -1, &msg, sizeof(msg)); + recv_msg(sock, NULL, NULL, 0); + + waitpid(pid, NULL, 0); +} + +int direct_ipc_start(pid_t *pid_out) { + if (!have_permissions()) { + return -1; + } + + int sock[2]; + if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sock) < 0) { + wlr_log_errno(L_ERROR, "Failed to create socket pair"); + return -1; + } + + pid_t pid = fork(); + if (pid < 0) { + wlr_log_errno(L_ERROR, "Fork failed"); + close(sock[0]); + close(sock[1]); + return -1; + } else if (pid == 0) { + close(sock[0]); + communicate(sock[1]); + _Exit(0); + } + + close(sock[1]); + *pid_out = pid; + return sock[0]; +} diff --git a/session/direct.c b/session/direct.c index 74f2faf1..1247663b 100644 --- a/session/direct.c +++ b/session/direct.c @@ -1,53 +1,238 @@ #define _POSIX_C_SOURCE 200809L #include #include +#include #include -#include -#include #include +#include +#include +#include +#include +#include +#include +#include +#include #include #include #include +#include "session/direct-ipc.h" + +enum { DRM_MAJOR = 226 }; const struct session_impl session_direct; struct direct_session { struct wlr_session base; + int tty_fd; + int old_kbmode; + int sock; + pid_t child; + + struct wl_event_source *vt_source; }; -static int direct_session_open(struct wlr_session *restrict base, - const char *restrict path) { - return open(path, O_RDWR | O_CLOEXEC); +static int direct_session_open(struct wlr_session *base, const char *path) { + struct direct_session *session = wl_container_of(base, session, base); + + int fd = direct_ipc_open(session->sock, path); + if (fd < 0) { + wlr_log(L_ERROR, "Failed to open %s: %s%s", path, strerror(-fd), + fd == -EINVAL ? "; is another display server running?" : ""); + return fd; + } + + struct stat st; + if (fstat(fd, &st) < 0) { + close(fd); + return -errno; + } + + if (major(st.st_rdev) == DRM_MAJOR) { + session->base.drm_fd = fd; + } + + return fd; } static void direct_session_close(struct wlr_session *base, int fd) { + struct direct_session *session = wl_container_of(base, session, base); + + struct stat st; + if (fstat(fd, &st) < 0) { + wlr_log_errno(L_ERROR, "Stat failed"); + close(fd); + return; + } + + if (major(st.st_rdev) == DRM_MAJOR) { + direct_ipc_dropmaster(session->sock, session->base.drm_fd); + session->base.drm_fd = -1; + } else if (major(st.st_rdev) == INPUT_MAJOR) { + ioctl(fd, EVIOCREVOKE, 0); + } + close(fd); } -static bool direct_change_vt(struct wlr_session *base, int vt) { - // TODO - return false; +static bool direct_change_vt(struct wlr_session *base, unsigned vt) { + struct direct_session *session = wl_container_of(base, session, base); + return ioctl(session->tty_fd, VT_ACTIVATE, (int)vt) == 0; } static void direct_session_finish(struct wlr_session *base) { struct direct_session *session = wl_container_of(base, session, base); + struct vt_mode mode = { + .mode = VT_AUTO, + }; + errno = 0; + + ioctl(session->tty_fd, KDSKBMODE, session->old_kbmode); + ioctl(session->tty_fd, KDSETMODE, KD_TEXT); + ioctl(session->tty_fd, VT_SETMODE, &mode); + + if (errno) { + wlr_log(L_ERROR, "Failed to restore tty"); + } + + direct_ipc_finish(session->sock, session->child); + close(session->sock); + + wl_event_source_remove(session->vt_source); + close(session->tty_fd); free(session); } +static int vt_handler(int signo, void *data) { + struct direct_session *session = data; + + if (session->base.active) { + session->base.active = false; + wl_signal_emit(&session->base.session_signal, session); + direct_ipc_dropmaster(session->sock, session->base.drm_fd); + ioctl(session->tty_fd, VT_RELDISP, 1); + } else { + ioctl(session->tty_fd, VT_RELDISP, VT_ACKACQ); + direct_ipc_setmaster(session->sock, session->base.drm_fd); + session->base.active = true; + wl_signal_emit(&session->base.session_signal, session); + } + + return 1; +} + +static bool setup_tty(struct direct_session *session, struct wl_display *display) { + int fd = dup(STDIN_FILENO); + if (fd == -1) { + wlr_log_errno(L_ERROR, "Cannot open tty"); + return false; + } + + struct stat st; + if (fstat(fd, &st) == -1 || major(st.st_rdev) != TTY_MAJOR || minor(st.st_rdev) == 0) { + wlr_log(L_ERROR, "Not running from a virtual terminal"); + goto error; + } + + int tty = minor(st.st_rdev); + int ret, kd_mode, old_kbmode; + + ret = ioctl(fd, KDGETMODE, &kd_mode); + if (ret) { + wlr_log_errno(L_ERROR, "Failed to get tty mode"); + goto error; + } + + if (kd_mode != KD_TEXT) { + wlr_log(L_ERROR, + "tty already in graphics mode; is another display server running?"); + goto error; + } + + ioctl(fd, VT_ACTIVATE, tty); + ioctl(fd, VT_WAITACTIVE, tty); + + if (ioctl(fd, KDGKBMODE, &old_kbmode)) { + wlr_log_errno(L_ERROR, "Failed to read keyboard mode"); + goto error; + } + + if (ioctl(fd, KDSKBMODE, K_OFF)) { + wlr_log_errno(L_ERROR, "Failed to set keyboard mode"); + goto error; + } + + if (ioctl(fd, KDSETMODE, KD_GRAPHICS)) { + wlr_log_errno(L_ERROR, "Failed to set graphics mode on tty"); + goto error; + } + + struct vt_mode mode = { + .mode = VT_PROCESS, + .relsig = SIGUSR1, + .acqsig = SIGUSR1, + }; + + if (ioctl(fd, VT_SETMODE, &mode) < 0) { + wlr_log(L_ERROR, "Failed to take control of tty"); + goto error; + } + + struct wl_event_loop *loop = wl_display_get_event_loop(display); + session->vt_source = wl_event_loop_add_signal(loop, SIGUSR1, + vt_handler, session); + if (!session->vt_source) { + goto error; + } + + session->base.vtnr = tty; + session->tty_fd = fd; + session->old_kbmode = old_kbmode; + + return true; + +error: + close(fd); + return false; +} + static struct wlr_session *direct_session_start(struct wl_display *disp) { struct direct_session *session = calloc(1, sizeof(*session)); if (!session) { - wlr_log(L_ERROR, "Allocation failed: %s", strerror(errno)); + wlr_log_errno(L_ERROR, "Allocation failed"); return NULL; } + session->sock = direct_ipc_start(&session->child); + if (session->sock == -1) { + goto error_session; + } + + if (!setup_tty(session, disp)) { + goto error_ipc; + } + + // XXX: Is it okay to trust the environment like this? + const char *seat = getenv("XDG_SEAT"); + if (!seat) { + seat = "seat0"; + } + wlr_log(L_INFO, "Successfully loaded direct session"); + snprintf(session->base.seat, sizeof(session->base.seat), "%s", seat); + session->base.drm_fd = -1; session->base.impl = &session_direct; session->base.active = true; wl_signal_init(&session->base.session_signal); return &session->base; + +error_ipc: + direct_ipc_finish(session->sock, session->child); + close(session->sock); +error_session: + free(session); + return NULL; } const struct session_impl session_direct = { diff --git a/session/logind.c b/session/logind.c index 6eb837ed..cfbdb4c7 100644 --- a/session/logind.c +++ b/session/logind.c @@ -26,13 +26,9 @@ struct logind_session { char *id; char *path; - char *seat; - - int drm_fd; }; -static int logind_take_device(struct wlr_session *restrict base, - const char *restrict path) { +static int logind_take_device(struct wlr_session *base, const char *path) { struct logind_session *session = wl_container_of(base, session, base); int ret; @@ -72,7 +68,7 @@ static int logind_take_device(struct wlr_session *restrict base, } if (major(st.st_rdev) == DRM_MAJOR) { - session->drm_fd = fd; + session->base.drm_fd = fd; } error: @@ -102,14 +98,14 @@ static void logind_release_device(struct wlr_session *base, int fd) { } if (major(st.st_rdev) == DRM_MAJOR) { - session->drm_fd = -1; + session->base.drm_fd = -1; } sd_bus_error_free(&error); sd_bus_message_unref(msg); } -static bool logind_change_vt(struct wlr_session *base, int vt) { +static bool logind_change_vt(struct wlr_session *base, unsigned vt) { struct logind_session *session = wl_container_of(base, session, base); int ret; @@ -187,7 +183,6 @@ static void logind_session_finish(struct wlr_session *base) { sd_bus_unref(session->bus); free(session->id); free(session->path); - free(session->seat); free(session); } @@ -242,7 +237,7 @@ static int resume_device(sd_bus_message *msg, void *userdata, sd_bus_error *ret_ } if (major == DRM_MAJOR) { - dup2(fd, session->drm_fd); + dup2(fd, session->base.drm_fd); session->base.active = true; wl_signal_emit(&session->base.session_signal, session); } @@ -305,11 +300,20 @@ static struct wlr_session *logind_session_start(struct wl_display *disp) { goto error; } - ret = sd_session_get_seat(session->id, &session->seat); + ret = sd_session_get_vt(session->id, &session->base.vtnr); + if (ret < 0) { + wlr_log(L_ERROR, "Session not running in virtual terminal"); + goto error; + } + + char *seat; + ret = sd_session_get_seat(session->id, &seat); if (ret < 0) { wlr_log(L_ERROR, "Failed to get seat id: %s", strerror(-ret)); goto error; } + snprintf(session->base.seat, sizeof(session->base.seat), "%s", seat); + free(seat); const char *fmt = "/org/freedesktop/login1/session/%s"; int len = snprintf(NULL, 0, fmt, session->id); @@ -345,7 +349,7 @@ static struct wlr_session *logind_session_start(struct wl_display *disp) { wlr_log(L_INFO, "Successfully loaded logind session"); - session->drm_fd = -1; + session->base.drm_fd = -1; session->base.impl = &session_logind; session->base.active = true; wl_signal_init(&session->base.session_signal); @@ -357,7 +361,6 @@ error_bus: error: free(session->path); free(session->id); - free(session->seat); return NULL; } diff --git a/session/session.c b/session/session.c index 9de93b1d..6f6aa2ea 100644 --- a/session/session.c +++ b/session/session.c @@ -33,9 +33,7 @@ void wlr_session_finish(struct wlr_session *session) { session->impl->finish(session); }; -int wlr_session_open_file(struct wlr_session *restrict session, - const char *restrict path) { - +int wlr_session_open_file(struct wlr_session *session, const char *path) { return session->impl->open(session, path); } @@ -43,6 +41,6 @@ void wlr_session_close_file(struct wlr_session *session, int fd) { session->impl->close(session, fd); } -bool wlr_session_change_vt(struct wlr_session *session, int vt) { +bool wlr_session_change_vt(struct wlr_session *session, unsigned vt) { return session->impl->change_vt(session, vt); }