From 71801cf3a9ee5cda62d830c46290ec77722eecb8 Mon Sep 17 00:00:00 2001
From: Lukas Arnold <lukas.arnold@stud.tu-darmstadt.de>
Date: Tue, 8 Nov 2022 22:10:54 +0100
Subject: libqmi-glib: allow qmux connection over unix domain socket

---
 src/libqmi-glib/qmi-endpoint-qmux.c | 67 +++++++++++++++++++++++++++++++++++++
 src/libqmi-glib/qmi-helpers.c       |  4 +++
 src/libqmi-glib/qmi-helpers.h       |  6 ++++
 3 files changed, 77 insertions(+)

(limited to 'src')

diff --git a/src/libqmi-glib/qmi-endpoint-qmux.c b/src/libqmi-glib/qmi-endpoint-qmux.c
index 444b8f6c..3a4cbdee 100644
--- a/src/libqmi-glib/qmi-endpoint-qmux.c
+++ b/src/libqmi-glib/qmi-endpoint-qmux.c
@@ -36,6 +36,7 @@
 #include "qmi-ctl.h"
 #include "qmi-errors.h"
 #include "qmi-error-types.h"
+#include "qmi-helpers.h"
 
 G_DEFINE_TYPE (QmiEndpointQmux, qmi_endpoint_qmux, QMI_TYPE_ENDPOINT)
 
@@ -342,6 +343,64 @@ create_iostream_with_socket (GTask *task)
     setup_iostream (task);
 }
 
+static void
+create_iostream_with_socket_direct (GTask *task)
+{
+    QmiEndpointQmux *self;
+    QmiFile *file;
+    GSocketAddress *socket_address;
+    GError *error = NULL;
+
+    self = g_task_get_source_object (task);
+
+    /* Create socket client */
+    self->priv->socket_client = g_socket_client_new ();
+    g_socket_client_set_family (self->priv->socket_client, G_SOCKET_FAMILY_UNIX);
+    g_socket_client_set_socket_type (self->priv->socket_client, G_SOCKET_TYPE_STREAM);
+    g_socket_client_set_protocol (self->priv->socket_client, G_SOCKET_PROTOCOL_DEFAULT);
+
+    /* Setup socket address (using a system path) */
+    g_object_get (self, QMI_ENDPOINT_FILE, &file, NULL);
+    socket_address = g_unix_socket_address_new_with_type (
+                         qmi_file_get_path (file),
+                         -1,
+                         G_UNIX_SOCKET_ADDRESS_PATH);
+
+    /* Connect to address */
+    self->priv->socket_connection = g_socket_client_connect (
+                                        self->priv->socket_client,
+                                        G_SOCKET_CONNECTABLE (socket_address),
+                                        NULL,
+                                        &error);
+    g_object_unref (socket_address);
+
+    /* Display an error if the socket is not reachable */
+    if (!self->priv->socket_connection) {
+        g_task_return_new_error (task,
+                            QMI_CORE_ERROR,
+                            QMI_CORE_ERROR_FAILED,
+                            "Cannot connect to the socket '%s': '%s'",
+                            qmi_file_get_path (file),
+                            error->message);
+        g_object_unref (file);
+        g_object_unref (task);
+        return;
+    }
+
+    g_object_unref (file);
+
+    /* Use the input and output streams of the socket */
+    self->priv->istream = g_io_stream_get_input_stream (G_IO_STREAM (self->priv->socket_connection));
+    if (self->priv->istream)
+        g_object_ref (self->priv->istream);
+
+    self->priv->ostream = g_io_stream_get_output_stream (G_IO_STREAM (self->priv->socket_connection));
+    if (self->priv->ostream)
+        g_object_ref (self->priv->ostream);
+
+    setup_iostream (task);
+}
+
 static void
 endpoint_open (QmiEndpoint         *endpoint,
                gboolean             use_proxy,
@@ -352,6 +411,7 @@ endpoint_open (QmiEndpoint         *endpoint,
 {
     QmiEndpointQmux *self;
     QmuxDeviceOpenContext *ctx;
+    QmiFile *file;
     GTask *task;
 
     ctx = g_slice_new (QmuxDeviceOpenContext);
@@ -373,10 +433,17 @@ endpoint_open (QmiEndpoint         *endpoint,
         return;
     }
 
+    /* Get the file name to determine whether a unix domain socket should be used instead of a device file */
+    g_object_get (self, QMI_ENDPOINT_FILE, &file, NULL);
+
     if (use_proxy)
         create_iostream_with_socket (task);
+    else if (g_strrstr (qmi_file_get_path (file), QMI_QMUX_SOCKET_FILE_NAME))
+        create_iostream_with_socket_direct (task);
     else
         create_iostream_with_fd (task);
+
+    g_object_unref (file);
 }
 
 /*****************************************************************************/
diff --git a/src/libqmi-glib/qmi-helpers.c b/src/libqmi-glib/qmi-helpers.c
index 4d93342c..2cd433fb 100644
--- a/src/libqmi-glib/qmi-helpers.c
+++ b/src/libqmi-glib/qmi-helpers.c
@@ -520,6 +520,10 @@ qmi_helpers_get_transport_type (const gchar  *path,
     if (g_file_test (rpmsg_sysfs_path, G_FILE_TEST_EXISTS))
         return QMI_HELPERS_TRANSPORT_TYPE_QMUX;
 
+    /* Allow libqmi to connect directly to a unix domain socket with a specific file name */
+    if (g_strrstr (device_basename, QMI_QMUX_SOCKET_FILE_NAME))
+        return QMI_HELPERS_TRANSPORT_TYPE_QMUX;
+
     g_set_error (error, QMI_CORE_ERROR, QMI_CORE_ERROR_FAILED,
                  "unexpected port subsystem");
     return QMI_HELPERS_TRANSPORT_TYPE_UNKNOWN;
diff --git a/src/libqmi-glib/qmi-helpers.h b/src/libqmi-glib/qmi-helpers.h
index 14fa6234..48b9f6df 100644
--- a/src/libqmi-glib/qmi-helpers.h
+++ b/src/libqmi-glib/qmi-helpers.h
@@ -60,6 +60,12 @@ typedef enum {
     QMI_HELPERS_TRANSPORT_TYPE_MBIM,
 } QmiHelpersTransportType;
 
+/*
+ * Symbol defining the file name for a unix domain socket used instead of a device file.
+ * The unix domain socket is addressed with the QMUX protocol.
+ */
+#define QMI_QMUX_SOCKET_FILE_NAME "qmux_socket"
+
 G_GNUC_INTERNAL
 QmiHelpersTransportType qmi_helpers_get_transport_type (const gchar  *path,
                                                         GError      **error);
-- 
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