[RFC PATCH 08/19] tools/vhost-user-rpmb: connect to fd and instantiate basic run loop

["Alex Bennée" <alex.bennee@linaro.org>]

Again doesn't do much on it's own but will create a socket and wait on
messages coming in from the vhost-user message socket.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tools/vhost-user-rpmb/main.c      | 211 +++++++++++++++++++++++++++++-
 tools/vhost-user-rpmb/meson.build |   2 +-
 2 files changed, 210 insertions(+), 3 deletions(-)

diff --git a/tools/vhost-user-rpmb/main.c b/tools/vhost-user-rpmb/main.c
index 6b1989125bd6..269c86cbb633 100644
--- a/tools/vhost-user-rpmb/main.c
+++ b/tools/vhost-user-rpmb/main.c
@@ -7,10 +7,23 @@
  */
 
 #include <glib.h>
+#include <gio/gio.h>
+#include <gio/gunixsocketaddress.h>
 #include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "contrib/libvhost-user/libvhost-user-glib.h"
+#include "contrib/libvhost-user/libvhost-user.h"
+
+#ifndef container_of
+#define container_of(ptr, type, member) ({                      \
+        const typeof(((type *) 0)->member) *__mptr = (ptr);     \
+        (type *) ((char *) __mptr - offsetof(type, member));})
+#endif
 
 static gchar *socket_path;
-static gint socket_fd;
+static gint socket_fd = -1;
 static gboolean print_cap;
 
 static GOptionEntry options[] =
@@ -21,6 +34,147 @@ static GOptionEntry options[] =
     { NULL }
 };
 
+enum {
+    VHOST_USER_RPMB_MAX_QUEUES = 1,
+};
+
+/* These structures are defined in the specification */
+
+struct virtio_rpmb_config {
+    uint8_t capacity;
+    uint8_t max_wr_cnt;
+    uint8_t max_rd_cnt;
+};
+
+struct virtio_rpmb_frame {
+    uint8_t stuff[196];
+    uint8_t key_mac[32];
+    uint8_t data[256];
+    uint8_t nonce[16];
+    /* remaining fields are big-endian */
+    uint32_t write_counter;
+    uint16_t address;
+    uint16_t block_count;
+    uint16_t result;
+    uint16_t req_resp;
+};
+
+/*
+ * Structure to track internal state of RPMB Device
+ */
+
+typedef struct VuRpmb {
+    VugDev dev;
+    struct virtio_rpmb_config virtio_config;
+} VuRpmb;
+
+struct virtio_rpmb_ctrl_command {
+    VuVirtqElement elem;
+    VuVirtq *vq;
+    struct virtio_rpmb_frame frame;
+    uint32_t error;
+    bool finished;
+};
+
+static void vrpmb_panic(VuDev *dev, const char *msg)
+{
+    g_critical("%s\n", msg);
+    exit(EXIT_FAILURE);
+}
+
+static uint64_t vrpmb_get_features(VuDev *dev)
+{
+    return 0;
+}
+
+static void vrpmb_set_features(VuDev *dev, uint64_t features)
+{
+    if (features) {
+        g_autoptr(GString) s = g_string_new("Requested un-handled feature");
+        g_string_append_printf(s, " 0x%" PRIx64 "", features);
+        g_info("%s: %s", __func__, s->str);
+    }
+}
+
+/*
+ * The configuration of the device is static and set when we start the
+ * daemon.
+ */
+static int
+vrpmb_get_config(VuDev *dev, uint8_t *config, uint32_t len)
+{
+    VuRpmb *r = container_of(dev, VuRpmb, dev.parent);
+    g_return_val_if_fail(len <= sizeof(struct virtio_rpmb_config), -1);
+    memcpy(config, &r->virtio_config, len);
+    return 0;
+}
+
+static int
+vrpmb_set_config(VuDev *dev, const uint8_t *data,
+                 uint32_t offset, uint32_t size,
+                 uint32_t flags)
+{
+    /* ignore */
+    return 0;
+}
+
+static void
+vrpmb_handle_ctrl(VuDev *dev, int qidx)
+{
+    VuVirtq *vq = vu_get_queue(dev, qidx);
+    struct virtio_rpmb_ctrl_command *cmd = NULL;
+
+    for (;;) {
+        cmd = vu_queue_pop(dev, vq, sizeof(struct virtio_rpmb_ctrl_command));
+        if (!cmd) {
+            break;
+        }
+
+        g_debug("un-handled cmd: %p", cmd);
+    }
+}
+
+static void
+vrpmb_queue_set_started(VuDev *dev, int qidx, bool started)
+{
+    VuVirtq *vq = vu_get_queue(dev, qidx);
+
+    g_debug("queue started %d:%d\n", qidx, started);
+
+    switch (qidx) {
+    case 0:
+        vu_set_queue_handler(dev, vq, started ? vrpmb_handle_ctrl : NULL);
+        break;
+    default:
+        break;
+    }
+}
+
+static int
+vrpmb_process_msg(VuDev *dev, VhostUserMsg *msg, int *do_reply)
+{
+    switch (msg->request) {
+    default:
+        return 0;
+    }
+
+    return 0;
+}
+
+static const VuDevIface vuiface = {
+    .set_features = vrpmb_set_features,
+    .get_features = vrpmb_get_features,
+    .queue_set_started = vrpmb_queue_set_started,
+    .process_msg = vrpmb_process_msg,
+    .get_config = vrpmb_get_config,
+    .set_config = vrpmb_set_config,
+};
+
+static void vrpmb_destroy(VuRpmb *r)
+{
+    vug_deinit(&r->dev);
+}
+
 /* Print vhost-user.json backend program capabilities */
 static void print_capabilities(void)
 {
@@ -33,8 +187,11 @@ int main (int argc, char *argv[])
 {
     GError *error = NULL;
     GOptionContext *context;
+    g_autoptr(GMainLoop) loop = NULL;
+    g_autoptr(GSocket) socket = NULL;
+    VuRpmb rpmb = {  };
 
-    context = g_option_context_new ("vhost-user-rpmb - vhost-user emulation of RPBM device");
+    context = g_option_context_new ("vhost-user emulation of RPBM device");
     g_option_context_add_main_entries (context, options, "vhost-user-rpmb");
     if (!g_option_context_parse (context, &argc, &argv, &error))
     {
@@ -47,4 +204,54 @@ int main (int argc, char *argv[])
         exit(0);
     }
 
+    if (!socket_path && socket_fd < 0) {
+        g_printerr("Please specify either --fd or --socket-path\n");
+        exit(EXIT_FAILURE);
+    }
+
+    /*
+     * Now create a vhost-user socket that we will receive messages
+     * on. Once we have our handler set up we can enter the glib main
+     * loop.
+     */
+    if (socket_path) {
+        g_autoptr(GSocketAddress) addr = g_unix_socket_address_new(socket_path);
+        g_autoptr(GSocket) bind_socket = g_socket_new(G_SOCKET_FAMILY_UNIX, G_SOCKET_TYPE_STREAM,
+                                                      G_SOCKET_PROTOCOL_DEFAULT, &error);
+
+        if (!g_socket_bind(bind_socket, addr, false, &error)) {
+            g_printerr("Failed to bind to socket at %s (%s).\n",
+                       socket_path, error->message);
+            exit(EXIT_FAILURE);
+        }
+        if (!g_socket_listen(bind_socket, &error)) {
+            g_printerr("Failed to listen on socket %s (%s).\n",
+                       socket_path, error->message);
+        }
+        g_message("awaiting connection to %s", socket_path);
+        socket = g_socket_accept(bind_socket, NULL, &error);
+        if (!socket) {
+            g_printerr("Failed to accept on socket %s (%s).\n",
+                       socket_path, error->message);
+        }
+    } else {
+        socket = g_socket_new_from_fd(socket_fd, &error);
+        if (!socket) {
+            g_printerr("Failed to connect to FD %d (%s).\n",
+                       socket_fd, error->message);
+            exit(EXIT_FAILURE);
+        }
+    }
+
+    if (!vug_init(&rpmb.dev, VHOST_USER_RPMB_MAX_QUEUES, g_socket_get_fd(socket),
+                  vrpmb_panic, &vuiface)) {
+        g_printerr("Failed to initialize libvhost-user-glib.\n");
+        exit(EXIT_FAILURE);
+    }
+
+    loop = g_main_loop_new(NULL, FALSE);
+    g_main_loop_run(loop);
+    g_main_loop_unref(loop);
+
+    vrpmb_destroy(&rpmb);
 }
diff --git a/tools/vhost-user-rpmb/meson.build b/tools/vhost-user-rpmb/meson.build
index e0df1b69a3fb..cf80bedd99ac 100644
--- a/tools/vhost-user-rpmb/meson.build
+++ b/tools/vhost-user-rpmb/meson.build
@@ -1,6 +1,6 @@
 executable('vhost-user-rpmb', files(
   'main.c'),
-  dependencies: [glib],
+  dependencies: [qemuutil, glib, gio],
   link_with: [libvhost_user],
   install: true,
   install_dir: get_option('libexecdir'))
-- 
2.20.1