module/i3: break out get_socket_address()

modules/i3-common.c

@@ -0,0 +1,88 @@
+#include "i3-common.h"
+
+#include <stdlib.h>
+#include <assert.h>
+
+#if defined(ENABLE_X11)
+ #include <xcb/xcb.h>
+ #include <xcb/xcb_aux.h>
+#endif
+
+#define LOG_MODULE "i3:common"
+#include "../log.h"
+
+#if defined(ENABLE_X11)
+ #include "../xcb.h"
+#endif
+
+#if defined(ENABLE_X11)
+static bool
+get_socket_address_x11(struct sockaddr_un *addr)
+{
+    int default_screen;
+    xcb_connection_t *conn = xcb_connect(NULL, &default_screen);
+    if (xcb_connection_has_error(conn) > 0) {
+        LOG_ERR("failed to connect to X");
+        xcb_disconnect(conn);
+        return false;
+    }
+
+    xcb_screen_t *screen = xcb_aux_get_screen(conn, default_screen);
+
+    xcb_atom_t atom = get_atom(conn, "I3_SOCKET_PATH");
+    assert(atom != XCB_ATOM_NONE);
+
+    xcb_get_property_cookie_t cookie
+        = xcb_get_property_unchecked(
+            conn, false, screen->root, atom,
+            XCB_GET_PROPERTY_TYPE_ANY, 0, sizeof(addr->sun_path));
+
+    xcb_generic_error_t *err;
+    xcb_get_property_reply_t *reply =
+        xcb_get_property_reply(conn, cookie, &err);
+
+    if (err != NULL) {
+        LOG_ERR("failed to get i3 socket path: %s", xcb_error(err));
+        free(err);
+        free(reply);
+        return false;
+    }
+
+    const int len = xcb_get_property_value_length(reply);
+    assert(len < sizeof(addr->sun_path));
+
+    if (len == 0) {
+        LOG_ERR("failed to get i3 socket path: empty reply");
+        free(reply);
+        return false;
+    }
+
+    memcpy(addr->sun_path, xcb_get_property_value(reply), len);
+    addr->sun_path[len] = '\0';
+
+    free(reply);
+    xcb_disconnect(conn);
+    return true;
+}
+#endif
+
+bool
+i3_get_socket_address(struct sockaddr_un *addr)
+{
+    *addr = (struct sockaddr_un){.sun_family = AF_UNIX};
+
+    const char *sway_sock = getenv("SWAYSOCK");
+    if (sway_sock == NULL) {
+        sway_sock = getenv("I3SOCK");
+        if (sway_sock == NULL) {
+#if defined(ENABLE_X11)
+            return get_socket_address_x11(addr);
+#else
+            return false;
+#endif
+        }
+    }
+
+    strncpy(addr->sun_path, sway_sock, sizeof(addr->sun_path) - 1);
+    return true;
+}