1 files changed, 72 insertions, 19 deletions

diff --git a/sway/config/output.c b/sway/config/output.c
index 0f238715..513d03e0 100644
--- a/sway/config/output.c
+++ b/sway/config/output.c
@@ -1,16 +1,17 @@
 #define _POSIX_C_SOURCE 200809L
 #include <assert.h>
+#include <fcntl.h>
 #include <stdbool.h>
 #include <string.h>
-#include <signal.h>
+#include <sys/socket.h>
 #include <sys/wait.h>
 #include <unistd.h>
-#include <wlr/types/wlr_output.h>
 #include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_output.h>
+#include "log.h"
 #include "sway/config.h"
 #include "sway/output.h"
 #include "sway/tree/root.h"
-#include "log.h"
 
 int output_name_cmp(const void *item, const void *data) {
         const struct output_config *output = item;
@@ -165,14 +166,71 @@ static bool set_mode(struct wlr_output *output, int width, int height,
         return wlr_output_set_mode(output, best);
 }
 
-void terminate_swaybg(pid_t pid) {
-        int ret = kill(pid, SIGTERM);
-        if (ret != 0) {
-                sway_log(SWAY_ERROR, "Unable to terminate swaybg [pid: %d]", pid);
-        } else {
-                int status;
-                waitpid(pid, &status, 0);
+static void handle_swaybg_client_destroy(struct wl_listener *listener,
+                void *data) {
+        struct sway_output *output =
+                wl_container_of(listener, output, swaybg_client_destroy);
+        wl_list_remove(&output->swaybg_client_destroy.link);
+        wl_list_init(&output->swaybg_client_destroy.link);
+        output->swaybg_client = NULL;
+}
+
+static bool spawn_swaybg(struct sway_output *output, char *const cmd[]) {
+        int sockets[2];
+        if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, sockets) != 0) {
+                sway_log_errno(SWAY_ERROR, "socketpair failed");
+                return false;
+        }
+
+        output->swaybg_client = wl_client_create(server.wl_display, sockets[0]);
+        if (output->swaybg_client == NULL) {
+                sway_log_errno(SWAY_ERROR, "wl_client_create failed");
+                return false;
+        }
+
+        output->swaybg_client_destroy.notify = handle_swaybg_client_destroy;
+        wl_client_add_destroy_listener(output->swaybg_client,
+                &output->swaybg_client_destroy);
+
+        pid_t pid = fork();
+        if (pid < 0) {
+                sway_log_errno(SWAY_ERROR, "fork failed");
+                return false;
+        } else if (pid == 0) {
+                pid = fork();
+                if (pid < 0) {
+                        sway_log_errno(SWAY_ERROR, "fork failed");
+                        exit(EXIT_FAILURE);
+                } else if (pid == 0) {
+                        // Remove the CLOEXEC flag
+                        int flags = fcntl(sockets[1], F_GETFD);
+                        if (flags == -1) {
+                                sway_log_errno(SWAY_ERROR, "fcntl() failed");
+                                exit(EXIT_FAILURE);
+                        }
+                        if (fcntl(sockets[1], F_SETFD, flags & ~FD_CLOEXEC) == -1) {
+                                sway_log_errno(SWAY_ERROR, "fcntl() failed");
+                                exit(EXIT_FAILURE);
+                        }
+
+                        char wayland_socket_str[16];
+                        snprintf(wayland_socket_str, sizeof(wayland_socket_str),
+                                "%d", sockets[1]);
+                        setenv("WAYLAND_SOCKET", wayland_socket_str, true);
+
+                        execvp(cmd[0], cmd);
+                        sway_log_errno(SWAY_ERROR, "execvp failed");
+                        exit(EXIT_FAILURE);
+                }
+                exit(EXIT_SUCCESS);
         }
+
+        if (waitpid(pid, NULL, 0) < 0) {
+                sway_log_errno(SWAY_ERROR, "waitpid failed");
+                return false;
+        }
+
+        return true;
 }
 
 bool apply_output_config(struct output_config *oc, struct sway_output *output) {
@@ -243,8 +301,8 @@ bool apply_output_config(struct output_config *oc, struct sway_output *output) {
                 wlr_output_layout_add_auto(root->output_layout, wlr_output);
         }
 
-        if (output->bg_pid != 0) {
-                terminate_swaybg(output->bg_pid);
+        if (output->swaybg_client != NULL) {
+                wl_client_destroy(output->swaybg_client);
         }
         if (oc && oc->background && config->swaybg_command) {
                 sway_log(SWAY_DEBUG, "Setting background for output %s to %s",
@@ -258,13 +316,8 @@ bool apply_output_config(struct output_config *oc, struct sway_output *output) {
                         oc->background_fallback ? oc->background_fallback : NULL,
                         NULL,
                 };
-
-                output->bg_pid = fork();
-                if (output->bg_pid < 0) {
-                        sway_log_errno(SWAY_ERROR, "fork failed");
-                } else if (output->bg_pid == 0) {
-                        execvp(cmd[0], cmd);
-                        sway_log_errno(SWAY_ERROR, "Failed to execute swaybg");
+                if (!spawn_swaybg(output, cmd)) {
+                        return false;
                 }
         }