Spawn swaynag as a wayland client

This spawns swaynag as a wayland client similar to how swaybar and
swaybg are already done

1 files changed, 95 insertions, 29 deletions

diff --git a/sway/swaynag.c b/sway/swaynag.c
index 49027f5d..0fca6c71 100644
--- a/sway/swaynag.c
+++ b/sway/swaynag.c
@@ -1,16 +1,32 @@
 #define _POSIX_C_SOURCE 200809L
-#include <fcntl.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <sys/socket.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <unistd.h>
 #include "log.h"
+#include "sway/server.h"
 #include "sway/swaynag.h"
+#include "util.h"
+
+static void handle_swaynag_client_destroy(struct wl_listener *listener,
+                void *data) {
+        struct swaynag_instance *swaynag =
+                wl_container_of(listener, swaynag, client_destroy);
+        wl_list_remove(&swaynag->client_destroy.link);
+        wl_list_init(&swaynag->client_destroy.link);
+        swaynag->client = NULL;
+}
 
 bool swaynag_spawn(const char *swaynag_command,
                 struct swaynag_instance *swaynag) {
+        if (swaynag->client != NULL) {
+                wl_client_destroy(swaynag->client);
+        }
+
         if (!swaynag_command) {
                 return true;
         }
@@ -20,44 +36,94 @@ bool swaynag_spawn(const char *swaynag_command,
                         sway_log(SWAY_ERROR, "Failed to create pipe for swaynag");
                         return false;
                 }
-                fcntl(swaynag->fd[1], F_SETFD, FD_CLOEXEC);
+                if (!set_cloexec(swaynag->fd[1], true)) {
+                        goto failed;
+                }
         }
 
-        pid_t pid;
-        if ((pid = fork()) == 0) {
-                if (swaynag->detailed) {
-                        close(swaynag->fd[1]);
-                        dup2(swaynag->fd[0], STDIN_FILENO);
-                        close(swaynag->fd[0]);
-                }
+        int sockets[2];
+        if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockets) != 0) {
+                sway_log_errno(SWAY_ERROR, "socketpair failed");
+                goto failed;
+        }
+        if (!set_cloexec(sockets[0], true) || !set_cloexec(sockets[1], true)) {
+                goto failed;
+        }
 
-                size_t length = strlen(swaynag_command) + strlen(swaynag->args) + 2;
-                char *cmd = malloc(length);
-                snprintf(cmd, length, "%s %s", swaynag_command, swaynag->args);
-                execl("/bin/sh", "/bin/sh", "-c", cmd, NULL);
-                _exit(0);
-        } else if (pid < 0) {
+        swaynag->client = wl_client_create(server.wl_display, sockets[0]);
+        if (swaynag->client == NULL) {
+                sway_log_errno(SWAY_ERROR, "wl_client_create failed");
+                goto failed;
+        }
+
+        swaynag->client_destroy.notify = handle_swaynag_client_destroy;
+        wl_client_add_destroy_listener(swaynag->client, &swaynag->client_destroy);
+
+        pid_t pid = fork();
+        if (pid < 0) {
                 sway_log(SWAY_ERROR, "Failed to create fork for swaynag");
-                if (swaynag->detailed) {
-                        close(swaynag->fd[0]);
-                        close(swaynag->fd[1]);
+                goto failed;
+        } else if (pid == 0) {
+                pid = fork();
+                if (pid < 0) {
+                        sway_log_errno(SWAY_ERROR, "fork failed");
+                        _exit(EXIT_FAILURE);
+                } else if (pid == 0) {
+                        if (!set_cloexec(sockets[1], false)) {
+                                _exit(EXIT_FAILURE);
+                        }
+
+                        if (swaynag->detailed) {
+                                close(swaynag->fd[1]);
+                                dup2(swaynag->fd[0], STDIN_FILENO);
+                                close(swaynag->fd[0]);
+                        }
+
+                        char wayland_socket_str[16];
+                        snprintf(wayland_socket_str, sizeof(wayland_socket_str),
+                                        "%d", sockets[1]);
+                        setenv("WAYLAND_SOCKET", wayland_socket_str, true);
+
+                        size_t length = strlen(swaynag_command) + strlen(swaynag->args) + 2;
+                        char *cmd = malloc(length);
+                        snprintf(cmd, length, "%s %s", swaynag_command, swaynag->args);
+                        execl("/bin/sh", "/bin/sh", "-c", cmd, NULL);
+                        sway_log_errno(SWAY_ERROR, "execl failed");
+                        _exit(EXIT_FAILURE);
                 }
-                return false;
+                _exit(EXIT_SUCCESS);
         }
 
         if (swaynag->detailed) {
-                close(swaynag->fd[0]);
+                if (close(swaynag->fd[0]) != 0) {
+                        sway_log_errno(SWAY_ERROR, "close failed");
+                        return false;
+                }
         }
-        swaynag->pid = pid;
-        return true;
-}
 
+        if (close(sockets[1]) != 0) {
+                sway_log_errno(SWAY_ERROR, "close failed");
+                return false;
+        }
+
+        if (waitpid(pid, NULL, 0) < 0) {
+                sway_log_errno(SWAY_ERROR, "waitpid failed");
+                return false;
+        }
 
-void swaynag_kill(struct swaynag_instance *swaynag) {
-        if (swaynag->pid > 0) {
-                kill(swaynag->pid, SIGTERM);
-                swaynag->pid = -1;
+        return true;
+
+failed:
+        if (swaynag->detailed) {
+                if (close(swaynag->fd[0]) != 0) {
+                        sway_log_errno(SWAY_ERROR, "close failed");
+                        return false;
+                }
+                if (close(swaynag->fd[1]) != 0) {
+                        sway_log_errno(SWAY_ERROR, "close failed");
+                }
         }
+        return false;
 }
 
 void swaynag_log(const char *swaynag_command, struct swaynag_instance *swaynag,
@@ -71,7 +137,7 @@ void swaynag_log(const char *swaynag_command, struct swaynag_instance *swaynag,
                 return;
         }
 
-        if (swaynag->pid <= 0 && !swaynag_spawn(swaynag_command, swaynag)) {
+        if (swaynag->client == NULL && !swaynag_spawn(swaynag_command, swaynag)) {
                 return;
         }
 
@@ -96,7 +162,7 @@ void swaynag_log(const char *swaynag_command, struct swaynag_instance *swaynag,
 }
 
 void swaynag_show(struct swaynag_instance *swaynag) {
-        if (swaynag->detailed && swaynag->pid > 0) {
+        if (swaynag->detailed && swaynag->client != NULL) {
                 close(swaynag->fd[1]);
         }
 }