wlroots/backend/session/session.c

438 lines
10 KiB
C

#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <libudev.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <wayland-server-core.h>
#include <wlr/backend/session.h>
#include <wlr/backend/session/interface.h>
#include <wlr/config.h>
#include <wlr/util/log.h>
#include <xf86drm.h>
#include <xf86drmMode.h>
#include "backend/session/session.h"
#include "util/signal.h"
extern const struct session_impl session_libseat;
extern const struct session_impl session_logind;
extern const struct session_impl session_direct;
extern const struct session_impl session_noop;
static const struct session_impl *impls[] = {
#if WLR_HAS_LIBSEAT
&session_libseat,
#endif
#if WLR_HAS_SYSTEMD || WLR_HAS_ELOGIND
&session_logind,
#endif
&session_direct,
NULL,
};
static bool is_drm_card(const char *sysname) {
const char prefix[] = "card";
if (strncmp(sysname, prefix, strlen(prefix)) != 0) {
return false;
}
for (size_t i = strlen(prefix); sysname[i] != '\0'; i++) {
if (sysname[i] < '0' || sysname[i] > '9') {
return false;
}
}
return true;
}
static int udev_event(int fd, uint32_t mask, void *data) {
struct wlr_session *session = data;
struct udev_device *udev_dev = udev_monitor_receive_device(session->mon);
if (!udev_dev) {
return 1;
}
const char *sysname = udev_device_get_sysname(udev_dev);
const char *devnode = udev_device_get_devnode(udev_dev);
const char *action = udev_device_get_action(udev_dev);
wlr_log(WLR_DEBUG, "udev event for %s (%s)", sysname, action);
if (!is_drm_card(sysname) || !action || !devnode) {
goto out;
}
const char *seat = udev_device_get_property_value(udev_dev, "ID_SEAT");
if (!seat) {
seat = "seat0";
}
if (session->seat[0] != '\0' && strcmp(session->seat, seat) != 0) {
goto out;
}
if (strcmp(action, "add") == 0) {
wlr_log(WLR_DEBUG, "DRM device %s added", sysname);
struct wlr_session_add_event event = {
.path = devnode,
};
wlr_signal_emit_safe(&session->events.add_drm_card, &event);
} else if (strcmp(action, "change") == 0) {
dev_t devnum = udev_device_get_devnum(udev_dev);
struct wlr_device *dev;
wl_list_for_each(dev, &session->devices, link) {
if (dev->dev == devnum) {
wlr_log(WLR_DEBUG, "DRM device %s changed", sysname);
wlr_signal_emit_safe(&dev->events.change, NULL);
break;
}
}
}
out:
udev_device_unref(udev_dev);
return 1;
}
static void handle_display_destroy(struct wl_listener *listener, void *data) {
struct wlr_session *session =
wl_container_of(listener, session, display_destroy);
wlr_session_destroy(session);
}
void session_init(struct wlr_session *session) {
wl_signal_init(&session->session_signal);
wl_signal_init(&session->events.add_drm_card);
wl_signal_init(&session->events.destroy);
wl_list_init(&session->devices);
}
struct wlr_session *wlr_session_create(struct wl_display *disp) {
struct wlr_session *session = NULL;
const char *env_wlr_session = getenv("WLR_SESSION");
if (env_wlr_session) {
if (strcmp(env_wlr_session, "libseat") == 0) {
#if WLR_HAS_LIBSEAT
session = session_libseat.create(disp);
#else
wlr_log(WLR_ERROR, "wlroots is not compiled with libseat support");
#endif
} else if (strcmp(env_wlr_session, "logind") == 0 ||
strcmp(env_wlr_session, "systemd") == 0) {
#if WLR_HAS_SYSTEMD || WLR_HAS_ELOGIND
session = session_logind.create(disp);
#else
wlr_log(WLR_ERROR, "wlroots is not compiled with logind support");
#endif
} else if (strcmp(env_wlr_session, "direct") == 0) {
session = session_direct.create(disp);
} else if (strcmp(env_wlr_session, "noop") == 0) {
session = session_noop.create(disp);
} else {
wlr_log(WLR_ERROR, "Unsupported WLR_SESSION: %s",
env_wlr_session);
}
} else {
const struct session_impl **iter;
for (iter = impls; !session && *iter; ++iter) {
session = (*iter)->create(disp);
}
}
if (!session) {
wlr_log(WLR_ERROR, "Failed to load session backend");
return NULL;
}
session->udev = udev_new();
if (!session->udev) {
wlr_log_errno(WLR_ERROR, "Failed to create udev context");
goto error_session;
}
session->mon = udev_monitor_new_from_netlink(session->udev, "udev");
if (!session->mon) {
wlr_log_errno(WLR_ERROR, "Failed to create udev monitor");
goto error_udev;
}
udev_monitor_filter_add_match_subsystem_devtype(session->mon, "drm", NULL);
udev_monitor_enable_receiving(session->mon);
struct wl_event_loop *event_loop = wl_display_get_event_loop(disp);
int fd = udev_monitor_get_fd(session->mon);
session->udev_event = wl_event_loop_add_fd(event_loop, fd,
WL_EVENT_READABLE, udev_event, session);
if (!session->udev_event) {
wlr_log_errno(WLR_ERROR, "Failed to create udev event source");
goto error_mon;
}
session->display = disp;
session->display_destroy.notify = handle_display_destroy;
wl_display_add_destroy_listener(disp, &session->display_destroy);
return session;
error_mon:
udev_monitor_unref(session->mon);
error_udev:
udev_unref(session->udev);
error_session:
session->impl->destroy(session);
return NULL;
}
void wlr_session_destroy(struct wlr_session *session) {
if (!session) {
return;
}
wlr_signal_emit_safe(&session->events.destroy, session);
wl_list_remove(&session->display_destroy.link);
wl_event_source_remove(session->udev_event);
udev_monitor_unref(session->mon);
udev_unref(session->udev);
session->impl->destroy(session);
}
struct wlr_device *wlr_session_open_file(struct wlr_session *session,
const char *path) {
int fd = session->impl->open(session, path);
if (fd < 0) {
return NULL;
}
struct wlr_device *dev = malloc(sizeof(*dev));
if (!dev) {
wlr_log_errno(WLR_ERROR, "Allocation failed");
goto error;
}
struct stat st;
if (fstat(fd, &st) < 0) {
wlr_log_errno(WLR_ERROR, "Stat failed");
goto error;
}
dev->fd = fd;
dev->dev = st.st_rdev;
wl_signal_init(&dev->events.change);
wl_list_insert(&session->devices, &dev->link);
return dev;
error:
free(dev);
close(fd);
return NULL;
}
void wlr_session_close_file(struct wlr_session *session,
struct wlr_device *dev) {
session->impl->close(session, dev->fd);
wl_list_remove(&dev->link);
free(dev);
}
bool wlr_session_change_vt(struct wlr_session *session, unsigned vt) {
if (!session) {
return false;
}
return session->impl->change_vt(session, vt);
}
/* Tests if 'path' is KMS compatible by trying to open it.
* It leaves the open device in *fd_out it it succeeds.
*/
static struct wlr_device *open_if_kms(struct wlr_session *restrict session,
const char *restrict path) {
if (!path) {
return NULL;
}
struct wlr_device *dev = wlr_session_open_file(session, path);
if (!dev) {
return NULL;
}
drmVersion *ver = drmGetVersion(dev->fd);
if (!ver) {
goto out_dev;
}
drmFreeVersion(ver);
return dev;
out_dev:
wlr_session_close_file(session, dev);
return NULL;
}
static size_t explicit_find_gpus(struct wlr_session *session,
size_t ret_len, struct wlr_device *ret[static ret_len], const char *str) {
char *gpus = strdup(str);
if (!gpus) {
wlr_log_errno(WLR_ERROR, "Allocation failed");
return 0;
}
size_t i = 0;
char *save;
char *ptr = strtok_r(gpus, ":", &save);
do {
if (i >= ret_len) {
break;
}
ret[i] = open_if_kms(session, ptr);
if (!ret[i]) {
wlr_log(WLR_ERROR, "Unable to open %s as DRM device", ptr);
} else {
++i;
}
} while ((ptr = strtok_r(NULL, ":", &save)));
free(gpus);
return i;
}
static struct udev_enumerate *enumerate_drm_cards(struct udev *udev) {
struct udev_enumerate *en = udev_enumerate_new(udev);
if (!en) {
wlr_log(WLR_ERROR, "udev_enumerate_new failed");
return NULL;
}
udev_enumerate_add_match_subsystem(en, "drm");
udev_enumerate_add_match_sysname(en, "card[0-9]*");
if (udev_enumerate_scan_devices(en) != 0) {
wlr_log(WLR_ERROR, "udev_enumerate_scan_devices failed");
udev_enumerate_unref(en);
return NULL;
}
return en;
}
struct find_gpus_add_handler {
bool added;
struct wl_listener listener;
};
static void find_gpus_handle_add(struct wl_listener *listener, void *data) {
struct find_gpus_add_handler *handler =
wl_container_of(listener, handler, listener);
handler->added = true;
}
/* Tries to find the primary GPU by checking for the "boot_vga" attribute.
* If it's not found, it returns the first valid GPU it finds.
*/
size_t wlr_session_find_gpus(struct wlr_session *session,
size_t ret_len, struct wlr_device **ret) {
const char *explicit = getenv("WLR_DRM_DEVICES");
if (explicit) {
return explicit_find_gpus(session, ret_len, ret, explicit);
}
struct udev_enumerate *en = enumerate_drm_cards(session->udev);
if (!en) {
return -1;
}
if (udev_enumerate_get_list_entry(en) == NULL) {
udev_enumerate_unref(en);
wlr_log(WLR_INFO, "Waiting for a DRM card device");
struct find_gpus_add_handler handler = {0};
handler.listener.notify = find_gpus_handle_add;
wl_signal_add(&session->events.add_drm_card, &handler.listener);
struct wl_event_loop *event_loop =
wl_display_get_event_loop(session->display);
while (!handler.added) {
int ret = wl_event_loop_dispatch(event_loop, -1);
if (ret < 0) {
wlr_log_errno(WLR_ERROR, "Failed to wait for DRM card device: "
"wl_event_loop_dispatch failed");
udev_enumerate_unref(en);
return -1;
}
}
wl_list_remove(&handler.listener.link);
en = enumerate_drm_cards(session->udev);
if (!en) {
return -1;
}
}
struct udev_list_entry *entry;
size_t i = 0;
udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(en)) {
if (i == ret_len) {
break;
}
bool is_boot_vga = false;
const char *path = udev_list_entry_get_name(entry);
struct udev_device *dev = udev_device_new_from_syspath(session->udev, path);
if (!dev) {
continue;
}
const char *seat = udev_device_get_property_value(dev, "ID_SEAT");
if (!seat) {
seat = "seat0";
}
if (session->seat[0] && strcmp(session->seat, seat) != 0) {
udev_device_unref(dev);
continue;
}
// This is owned by 'dev', so we don't need to free it
struct udev_device *pci =
udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
if (pci) {
const char *id = udev_device_get_sysattr_value(pci, "boot_vga");
if (id && strcmp(id, "1") == 0) {
is_boot_vga = true;
}
}
struct wlr_device *wlr_dev =
open_if_kms(session, udev_device_get_devnode(dev));
if (!wlr_dev) {
udev_device_unref(dev);
continue;
}
udev_device_unref(dev);
ret[i] = wlr_dev;
if (is_boot_vga) {
struct wlr_device *tmp = ret[0];
ret[0] = ret[i];
ret[i] = tmp;
}
++i;
}
udev_enumerate_unref(en);
return i;
}