[Qemu-devel] [RFC][PATCH 02/10] virtagent: base definitions for host/guest RPC daemon

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Basic skeleton code for RPC daemon loop. This is shared by both the
guest-side RPC server as well as the host-side one (the advertised RPCs
for each by guest/host-specific arrays).

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 virtagent-daemon.c |  118 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 virtagent-daemon.h |   20 +++++++++
 2 files changed, 138 insertions(+), 0 deletions(-)
 create mode 100644 virtagent-daemon.c
 create mode 100644 virtagent-daemon.h

diff --git a/virtagent-daemon.c b/virtagent-daemon.c
new file mode 100644
index 0000000..998b025
--- /dev/null
+++ b/virtagent-daemon.c
@@ -0,0 +1,118 @@
+/*
+ * virt-agent - host/guest RPC daemon functions
+ *
+ * Copyright IBM Corp. 2010
+ *
+ * Authors:
+ *  Adam Litke        <aglitke@linux.vnet.ibm.com>
+ *  Michael Roth      <mdroth@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <xmlrpc-c/base.h>
+#include <xmlrpc-c/server.h>
+#include <xmlrpc-c/server_abyss.h>
+#include "qemu_socket.h"
+#include "virtagent-daemon.h"
+#include "virtagent-common.h"
+
+static int va_accept(int listen_fd) {
+    struct sockaddr_in saddr;
+    struct sockaddr *addr;
+    socklen_t len;
+    int fd;
+
+    while (1) {
+        len = sizeof(saddr);
+        addr = (struct sockaddr *)&saddr;
+        fd = qemu_accept(listen_fd, addr, &len);
+        if (fd < 0 && errno != EINTR) {
+            LOG("accept() failed");
+            break;
+        } else if (fd >= 0) {
+            TRACE("accepted connection");
+            break;
+        }
+    }
+    return fd;
+}
+
+typedef struct RPCFunction {
+    xmlrpc_value *(*func)(xmlrpc_env *env, xmlrpc_value *param, void *unused);
+    const char *func_name;
+} RPCFunction;
+
+static RPCFunction guest_functions[] = {
+    { NULL, NULL }
+};
+static RPCFunction host_functions[] = {
+    { NULL, NULL }
+};
+
+static void va_register_functions(xmlrpc_env *env, xmlrpc_registry *registry,
+                                  RPCFunction *list)
+{
+    int i;
+    for (i = 0; list[i].func != NULL; ++i) {
+        TRACE("adding func: %s", list[i].func_name);
+        xmlrpc_registry_add_method(env, registry, NULL, list[i].func_name,
+                                   list[i].func, NULL);
+    }
+}
+
+int va_server_loop(int listen_fd, bool is_host)
+{
+    xmlrpc_registry *registryP;
+    xmlrpc_env env;
+    int ret, fd;
+    char *rpc_request;
+    int rpc_request_len;
+    xmlrpc_mem_block *rpc_response;
+    RPCFunction *func_list = is_host ? host_functions : guest_functions;
+
+    xmlrpc_env_init(&env);
+    registryP = xmlrpc_registry_new(&env);
+    va_register_functions(&env, registryP, func_list);
+
+    while (1) {
+        TRACE("waiting for connection from RPC client");
+        fd = va_accept(listen_fd);
+        if (fd < 0) {
+            TRACE("connection error: %s", strerror(errno));
+            continue;
+        }
+        TRACE("RPC client connected, fetching RPC...");
+        ret = va_get_rpc_request(fd, &rpc_request, &rpc_request_len);
+        if (ret != 0 || rpc_request == NULL) {
+            LOG("error retrieving rpc request");
+            goto out;
+        }
+        TRACE("handling RPC request");
+        rpc_response = xmlrpc_registry_process_call(&env, registryP, NULL,
+                                                    rpc_request,
+                                                    rpc_request_len);
+        if (rpc_response == NULL) {
+            LOG("error handling rpc request");
+            goto out;
+        }
+
+        qemu_free(rpc_request);
+        TRACE("sending RPC response");
+        ret = va_send_rpc_response(fd, rpc_response);
+        if (ret != 0) {
+            LOG("error sending rpc response");
+            goto out;
+        }
+        TRACE("RPC completed");
+        XMLRPC_MEMBLOCK_FREE(char, rpc_response);
+out:
+        closesocket(fd);
+    }
+
+    return 0;
+}
diff --git a/virtagent-daemon.h b/virtagent-daemon.h
new file mode 100644
index 0000000..bb197d0
--- /dev/null
+++ b/virtagent-daemon.h
@@ -0,0 +1,20 @@
+/*
+ * virt-agent - host/guest RPC daemon functions
+ *
+ * Copyright IBM Corp. 2010
+ *
+ * Authors:
+ *  Michael Roth      <mdroth@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#define GUEST_AGENT_SERVICE_ID "virtagent"
+#define GUEST_AGENT_PATH "/tmp/virtagent-guest.sock"
+#define HOST_AGENT_SERVICE_ID "virtagent-host"
+#define HOST_AGENT_PATH "/tmp/virtagent-host.sock"
+#define VA_GETFILE_MAX 1 << 30
+#define VA_FILEBUF_LEN 16384
+
+int va_server_loop(int listen_fd, bool is_host);
-- 
1.7.0.4