1 files changed, 166 insertions, 0 deletions
diff --git a/tests/auto/client/reconnect/wl-socket.c b/tests/auto/client/reconnect/wl-socket.c
new file mode 100644
index 000000000..3d4491622
--- /dev/null
+++ b/tests/auto/client/reconnect/wl-socket.c
@@ -0,0 +1,166 @@
+// Copyright (C) 2023 David Edmundson <davidedmundson@kde.org>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#define _DEFAULT_SOURCE
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/file.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+/* This is the size of the char array in struct sock_addr_un.
+ * No Wayland socket can be created with a path longer than this,
+ * including the null terminator.
+ */
+#ifndef UNIX_PATH_MAX
+#define UNIX_PATH_MAX 108
+#endif
+
+#define LOCK_SUFFIX ".lock"
+#define LOCK_SUFFIXLEN 5
+
+struct wl_socket {
+    int fd;
+    int fd_lock;
+    struct sockaddr_un addr;
+    char lock_addr[UNIX_PATH_MAX + LOCK_SUFFIXLEN];
+    char display_name[16];
+};
+
+static struct wl_socket *wl_socket_alloc(void)
+{
+    struct wl_socket *s;
+
+    s = malloc(sizeof *s);
+    if (!s)
+        return NULL;
+
+    s->fd = -1;
+    s->fd_lock = -1;
+
+    return s;
+}
+
+static int wl_socket_lock(struct wl_socket *socket)
+{
+    struct stat socket_stat;
+
+    snprintf(socket->lock_addr, sizeof socket->lock_addr, "%s%s", socket->addr.sun_path, LOCK_SUFFIX);
+
+    // differening from kwin, we're back to setting CLOEXEC as we're all in process
+    socket->fd_lock = open(socket->lock_addr, O_CREAT | O_RDWR | O_CLOEXEC, (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
+
+    if (socket->fd_lock < 0) {
+        printf("unable to open lockfile %s check permissions\n", socket->lock_addr);
+        goto err;
+    }
+
+    if (flock(socket->fd_lock, LOCK_EX | LOCK_NB) < 0) {
+        printf("unable to lock lockfile %s, maybe another compositor is running\n", socket->lock_addr);
+        goto err_fd;
+    }
+
+    if (lstat(socket->addr.sun_path, &socket_stat) < 0) {
+        if (errno != ENOENT) {
+            printf("did not manage to stat file %s\n", socket->addr.sun_path);
+            goto err_fd;
+        }
+    } else if (socket_stat.st_mode & S_IWUSR || socket_stat.st_mode & S_IWGRP) {
+        unlink(socket->addr.sun_path);
+    }
+
+    return 0;
+err_fd:
+    close(socket->fd_lock);
+    socket->fd_lock = -1;
+err:
+    *socket->lock_addr = 0;
+    /* we did not set this value here, but without lock the
+     * socket won't be created anyway. This prevents the
+     * wl_socket_destroy from unlinking already existing socket
+     * created by other compositor */
+    *socket->addr.sun_path = 0;
+
+    return -1;
+}
+
+void wl_socket_destroy(struct wl_socket *s)
+{
+    if (s->addr.sun_path[0])
+        unlink(s->addr.sun_path);
+    if (s->fd >= 0)
+        close(s->fd);
+    if (s->lock_addr[0])
+        unlink(s->lock_addr);
+    if (s->fd_lock >= 0)
+        close(s->fd_lock);
+
+    free(s);
+}
+
+const char *wl_socket_get_display_name(struct wl_socket *s)
+{
+    return s->display_name;
+}
+
+int wl_socket_get_fd(struct wl_socket *s)
+{
+    return s->fd;
+}
+
+struct wl_socket *wl_socket_create()
+{
+    struct wl_socket *s;
+    int displayno = 0;
+    int name_size;
+
+    /* A reasonable number of maximum default sockets. If
+     * you need more than this, use the explicit add_socket API. */
+    const int MAX_DISPLAYNO = 32;
+    const char *runtime_dir = getenv("XDG_RUNTIME_DIR");
+    if (!runtime_dir) {
+        printf("XDG_RUNTIME_DIR not set");
+        return NULL;
+    }
+
+    s = wl_socket_alloc();
+    if (s == NULL)
+        return NULL;
+
+    do {
+        snprintf(s->display_name, sizeof s->display_name, "wayland-%d", displayno);
+        s->addr.sun_family = AF_LOCAL;
+        name_size = snprintf(s->addr.sun_path, sizeof s->addr.sun_path, "%s/%s", runtime_dir, s->display_name) + 1;
+        assert(name_size > 0);
+
+        if (name_size > (int)sizeof s->addr.sun_path) {
+            goto fail;
+        }
+
+        if (wl_socket_lock(s) < 0)
+            continue;
+
+        s->fd = socket(PF_LOCAL, SOCK_STREAM, 0);
+
+        int size = SUN_LEN(&s->addr);
+        int ret = bind(s->fd, (struct sockaddr*)&s->addr, size);
+        if (ret < 0) {
+            goto fail;
+        }
+        ret = listen(s->fd, 128);
+        if (ret < 0) {
+            goto fail;
+        }
+        return s;
+    } while (displayno++ < MAX_DISPLAYNO);
+
+fail:
+    wl_socket_destroy(s);
+    return NULL;
+}