ENH: Initial import

1 files changed, 829 insertions, 0 deletions

diff --git a/Utilities/cmxmlrpc/xmlrpc_registry.c b/Utilities/cmxmlrpc/xmlrpc_registry.c
new file mode 100644
index 0000000..41e5ac1
--- /dev/null
+++ b/Utilities/cmxmlrpc/xmlrpc_registry.c
@@ -0,0 +1,829 @@
+/* Copyright (C) 2001 by First Peer, Inc. All rights reserved.
+** Copyright (C) 2001 by Eric Kidd. All rights reserved.
+** Copyright (C) 2001 by Luke Howard. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions
+** are met:
+** 1. Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+** 2. Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in the
+**    documentation and/or other materials provided with the distribution.
+** 3. The name of the author may not be used to endorse or promote products
+**    derived from this software without specific prior written permission. 
+**  
+** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+** SUCH DAMAGE. */
+
+#include "xmlrpc_config.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "xmlrpc.h"
+#include "xmlrpc_server.h"
+#include "xmlrpc_int.h"
+
+/*=========================================================================
+**  XML-RPC Server Method Registry
+**=========================================================================
+**  A method registry maintains a list of functions, and handles
+**  dispatching. To build an XML-RPC server, just add a communications
+**  protocol. :-)
+*/
+
+static void
+install_system_methods (xmlrpc_env *env, xmlrpc_registry *registry);
+
+xmlrpc_registry *
+xmlrpc_registry_new(xmlrpc_env *env) {
+
+    xmlrpc_value *methods;
+    xmlrpc_registry *registry;
+    int registry_valid;
+    
+    XMLRPC_ASSERT_ENV_OK(env);
+    
+    /* Error-handling preconditions. */
+    methods = NULL;
+    registry = NULL;
+    registry_valid = 0;
+
+    /* Allocate our memory. */
+    methods = xmlrpc_struct_new(env);
+    XMLRPC_FAIL_IF_FAULT(env);
+    registry = (xmlrpc_registry*) malloc(sizeof(xmlrpc_registry));
+    XMLRPC_FAIL_IF_NULL(registry, env, XMLRPC_INTERNAL_ERROR,
+                        "Could not allocate memory for registry");
+    
+    /* Set everything up. */
+    registry->_introspection_enabled = 1;
+    registry->_methods = methods;
+    registry->_default_method = NULL;
+    registry->_preinvoke_method = NULL;
+    registry_valid = 1;
+
+    /* Install our system methods. */
+    install_system_methods(env, registry);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+ cleanup:
+    if (env->fault_occurred) {
+        if (registry_valid) {
+            xmlrpc_registry_free(registry);
+        } else {
+            if (methods)
+                xmlrpc_DECREF(methods);
+            if (registry)
+                free(registry);
+        }
+        return NULL;
+    }
+    return registry;
+}
+
+
+
+void 
+xmlrpc_registry_free(xmlrpc_registry * registry) {
+
+    XMLRPC_ASSERT_PTR_OK(registry);
+    XMLRPC_ASSERT(registry->_methods != XMLRPC_BAD_POINTER);
+
+    xmlrpc_DECREF(registry->_methods);
+    registry->_methods = XMLRPC_BAD_POINTER;
+    if (registry->_default_method != NULL)
+        xmlrpc_DECREF(registry->_default_method);
+    if (registry->_preinvoke_method != NULL)
+        xmlrpc_DECREF(registry->_preinvoke_method);
+    free(registry);
+}
+
+
+
+/*=========================================================================
+**  xmlrpc_registry_disable_introspection
+**=========================================================================
+**  See xmlrpc.h for more documentation.
+*/
+
+void 
+xmlrpc_registry_disable_introspection(xmlrpc_registry * registry) {
+    XMLRPC_ASSERT_PTR_OK(registry);
+    registry->_introspection_enabled = 0;
+}
+
+
+
+/*=========================================================================
+**  xmlrpc_registry_add_method
+**=========================================================================
+**  See xmlrpc.h for more documentation.
+*/
+
+void 
+xmlrpc_registry_add_method(xmlrpc_env *env,
+                           xmlrpc_registry *registry,
+                           const char *host,
+                           const char *method_name,
+                           xmlrpc_method method,
+                           void *user_data) {
+
+    xmlrpc_registry_add_method_w_doc (env, registry, host, method_name,
+                      method, user_data, "?",
+                      "No help is available for this method.");
+}
+
+
+
+void 
+xmlrpc_registry_add_method_w_doc(xmlrpc_env *env,
+                                 xmlrpc_registry *registry,
+                                 const char *host,
+                                 const char *method_name,
+                                 xmlrpc_method method,
+                                 void *user_data,
+                                 const char *signature,
+                                 const char *help) {
+    xmlrpc_value *method_info;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_PTR_OK(registry);
+    XMLRPC_ASSERT(host == NULL);
+    XMLRPC_ASSERT_PTR_OK(method_name);
+    XMLRPC_ASSERT_PTR_OK(method);
+
+    /* Error-handling preconditions. */
+    method_info = NULL;
+
+    /* Store our method and user data into our hash table. */
+    method_info = xmlrpc_build_value(env, "(ppss)", (void*) method, user_data,
+                                     signature, help);
+    XMLRPC_FAIL_IF_FAULT(env);
+    xmlrpc_struct_set_value(env, registry->_methods, method_name, method_info);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+ cleanup:
+    if (method_info)
+    xmlrpc_DECREF(method_info);
+
+}
+
+
+
+/*=========================================================================
+**  xmlrpc_registry_set_default_method
+**=========================================================================
+**  See xmlrpc.h for more documentation.
+*/
+
+void 
+xmlrpc_registry_set_default_method(xmlrpc_env *env,
+                                   xmlrpc_registry *registry,
+                                   xmlrpc_default_method handler,
+                                   void *user_data) {
+    xmlrpc_value *method_info;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_PTR_OK(registry);
+    XMLRPC_ASSERT_PTR_OK(handler);
+
+    /* Error-handling preconditions. */
+    method_info = NULL;
+    
+    /* Store our method and user data into our hash table. */
+    method_info = xmlrpc_build_value(env, "(pp)", (void*) handler, user_data);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+    /* Dispose of any pre-existing default method and install ours. */
+    if (registry->_default_method)
+        xmlrpc_DECREF(registry->_default_method);
+    registry->_default_method = method_info;
+    
+cleanup:
+    if (env->fault_occurred) {
+        if (method_info)
+            xmlrpc_DECREF(method_info);
+    }
+}
+
+
+
+/*=========================================================================
+**  xmlrpc_registry_set_preinvoke_method
+**=========================================================================
+**  See xmlrpc.h for more documentation.
+*/
+
+void 
+xmlrpc_registry_set_preinvoke_method(xmlrpc_env *env,
+                                     xmlrpc_registry *registry,
+                                     xmlrpc_preinvoke_method handler,
+                                     void *user_data) {
+    xmlrpc_value *method_info;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_PTR_OK(registry);
+    XMLRPC_ASSERT_PTR_OK(handler);
+
+    /* Error-handling preconditions. */
+    method_info = NULL;
+
+    /* Store our method and user data into our hash table. */
+    method_info = xmlrpc_build_value(env, "(pp)", (void*) handler, user_data);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+    /* Dispose of any pre-existing preinvoke method and install ours. */
+    if (registry->_preinvoke_method)
+        xmlrpc_DECREF(registry->_preinvoke_method);
+    registry->_preinvoke_method = method_info;
+
+ cleanup:
+    if (env->fault_occurred) {
+        if (method_info)
+            xmlrpc_DECREF(method_info);
+    }
+}
+
+
+
+/*=========================================================================
+**  dispatch_call
+**=========================================================================
+**  An internal method which actually does the dispatch. This may get
+**  prettified and exported at some point in the future.
+*/
+
+static void
+callPreinvokeMethodIfAny(xmlrpc_env *      const envP,
+                         xmlrpc_registry * const registryP,
+                         const char *      const methodName,
+                         xmlrpc_value *    const paramArrayP) {
+
+    /* Get the preinvoke method, if it is set. */
+    if (registryP->_preinvoke_method) {
+        xmlrpc_preinvoke_method preinvoke_method;
+        void * user_data;
+
+        xmlrpc_parse_value(envP, registryP->_preinvoke_method, "(pp)",
+                           &preinvoke_method, &user_data);
+        if (!envP->fault_occurred)
+            (*preinvoke_method)(envP, methodName,
+                                paramArrayP, user_data);
+    }
+}
+
+
+
+static void
+callDefaultMethod(xmlrpc_env *    const envP,
+                  xmlrpc_value *  const defaultMethodInfo,
+                  const char *    const methodName,
+                  xmlrpc_value *  const paramArrayP,
+                  xmlrpc_value ** const resultPP) {
+
+    xmlrpc_default_method default_method;
+    void * user_data;
+
+    xmlrpc_parse_value(envP, defaultMethodInfo, "(pp)",
+                       &default_method, &user_data);
+
+    if (!envP->fault_occurred)
+        *resultPP = (*default_method)(envP, NULL, methodName,
+                                      paramArrayP, user_data);
+}
+    
+
+
+static void
+callNamedMethod(xmlrpc_env *    const envP,
+                xmlrpc_value *  const methodInfo,
+                xmlrpc_value *  const paramArrayP,
+                xmlrpc_value ** const resultPP) {
+
+    xmlrpc_method method;
+    void * user_data;
+    
+    xmlrpc_parse_value(envP, methodInfo, "(pp*)", &method, &user_data);
+    if (!envP->fault_occurred)
+        *resultPP = (*method)(envP, paramArrayP, user_data);
+}
+
+
+
+static void
+dispatch_call(xmlrpc_env *      const envP, 
+              xmlrpc_registry * const registryP,
+              const char *      const methodName, 
+              xmlrpc_value *    const paramArrayP,
+              xmlrpc_value **   const resultPP) {
+
+    callPreinvokeMethodIfAny(envP, registryP, methodName, paramArrayP);
+    if (!envP->fault_occurred) {
+        xmlrpc_value * method_info;
+
+        /* Look up the method info for the named method. */
+        xmlrpc_struct_find_value(envP, registryP->_methods,
+                                 methodName, &method_info);
+        if (!envP->fault_occurred) {
+            if (method_info)
+                callNamedMethod(envP, method_info, paramArrayP, resultPP);
+            else {
+                if (registryP->_default_method)
+                    callDefaultMethod(envP, registryP->_default_method, 
+                                      methodName, paramArrayP,
+                                      resultPP);
+                else {
+                    /* No matching method, and no default. */
+                    xmlrpc_env_set_fault_formatted(
+                        envP, XMLRPC_NO_SUCH_METHOD_ERROR,
+                        "Method '%s' not defined", methodName);
+                }
+            } 
+        }
+    }
+    /* For backward compatibility, for sloppy users: */
+    if (envP->fault_occurred)
+        *resultPP = NULL;
+}
+
+
+
+/*=========================================================================
+**  xmlrpc_registry_process_call
+**=========================================================================
+**
+*/
+
+xmlrpc_mem_block *
+xmlrpc_registry_process_call(xmlrpc_env *      const envP,
+                             xmlrpc_registry * const registryP,
+                             const char *      const host ATTR_UNUSED,
+                             const char *      const xml_data,
+                             size_t            const xml_len) {
+
+    xmlrpc_mem_block * output;
+
+    XMLRPC_ASSERT_ENV_OK(envP);
+    XMLRPC_ASSERT_PTR_OK(xml_data);
+    
+    xmlrpc_traceXml("XML-RPC CALL", xml_data, xml_len);
+
+    /* Allocate our output buffer.
+    ** If this fails, we need to die in a special fashion. */
+    output = XMLRPC_MEMBLOCK_NEW(char, envP, 0);
+    if (!envP->fault_occurred) {
+        const char * methodName;
+        xmlrpc_value * paramArray;
+        xmlrpc_env fault;
+
+        xmlrpc_env_init(&fault);
+
+        xmlrpc_parse_call(&fault, xml_data, xml_len, 
+                          &methodName, &paramArray);
+
+        if (!fault.fault_occurred) {
+            xmlrpc_value * result;
+            
+            dispatch_call(&fault, registryP, methodName, paramArray, &result);
+
+            if (!fault.fault_occurred) {
+                xmlrpc_serialize_response(envP, output, result);
+
+                /* A comment here used to say that
+                   xmlrpc_serialize_response() could fail and "leave
+                   stuff in the buffer."  Don't know what that means,
+                   but it sounds like something that needs to be
+                   fixed.  The old code aborted the program here if
+                   xmlrpc_serialize_repsonse() failed.  04.11.17 
+                */
+                xmlrpc_DECREF(result);
+            } 
+            xmlrpc_strfree(methodName);
+            xmlrpc_DECREF(paramArray);
+        }
+        if (!envP->fault_occurred && fault.fault_occurred)
+            xmlrpc_serialize_fault(envP, output, &fault);
+
+        xmlrpc_env_clean(&fault);
+
+        if (envP->fault_occurred)
+            XMLRPC_MEMBLOCK_FREE(char, output);
+        else
+            xmlrpc_traceXml("XML-RPC RESPONSE", 
+                            XMLRPC_MEMBLOCK_CONTENTS(char, output),
+                            XMLRPC_MEMBLOCK_SIZE(char, output));
+    }
+    return output;
+}
+
+
+
+/*=========================================================================
+**  system.multicall
+**=========================================================================
+**  Low-tech support for transparent, boxed methods.
+*/
+
+static char *multicall_help =
+"Process an array of calls, and return an array of results. Calls should "
+"be structs of the form {'methodName': string, 'params': array}. Each "
+"result will either be a single-item array containg the result value, or "
+"a struct of the form {'faultCode': int, 'faultString': string}. This "
+"is useful when you need to make lots of small calls without lots of "
+"round trips.";
+
+static xmlrpc_value *
+call_one_method(xmlrpc_env *env, xmlrpc_registry *registry,
+                xmlrpc_value *method_info) {
+
+    xmlrpc_value *result_val, *result;
+    char *method_name;
+    xmlrpc_value *param_array;
+
+    /* Error-handling preconditions. */
+    result = result_val = NULL;
+    
+    /* Extract our method name and parameters. */
+    xmlrpc_parse_value(env, method_info, "{s:s,s:A,*}",
+                       "methodName", &method_name,
+                       "params", &param_array);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+    /* Watch out for a deep recursion attack. */
+    if (strcmp(method_name, "system.multicall") == 0)
+        XMLRPC_FAIL(env, XMLRPC_REQUEST_REFUSED_ERROR,
+                    "Recursive system.multicall strictly forbidden");
+    
+    /* Perform the call. */
+    dispatch_call(env, registry, method_name, param_array, &result_val);
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+    /* Build our one-item result array. */
+    result = xmlrpc_build_value(env, "(V)", result_val);
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+ cleanup:
+    if (result_val)
+        xmlrpc_DECREF(result_val);
+    if (env->fault_occurred) {
+        if (result)
+            xmlrpc_DECREF(result);
+        return NULL;
+    }
+    return result;
+}
+
+
+
+static xmlrpc_value *
+system_multicall(xmlrpc_env *env,
+                 xmlrpc_value *param_array,
+                 void *user_data) {
+
+    xmlrpc_registry *registry;
+    xmlrpc_value *methlist, *methinfo, *results, *result;
+    size_t size, i;
+    xmlrpc_env env2;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_VALUE_OK(param_array);
+    XMLRPC_ASSERT_PTR_OK(user_data);
+
+    /* Error-handling preconditions. */
+    results = result = NULL;
+    xmlrpc_env_init(&env2);
+    
+    /* Turn our arguments into something more useful. */
+    registry = (xmlrpc_registry*) user_data;
+    xmlrpc_parse_value(env, param_array, "(A)", &methlist);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+    /* Create an empty result list. */
+    results = xmlrpc_build_value(env, "()");
+    XMLRPC_FAIL_IF_FAULT(env);
+
+    /* Loop over our input list, calling each method in turn. */
+    size = xmlrpc_array_size(env, methlist);
+    XMLRPC_ASSERT_ENV_OK(env);
+    for (i = 0; i < size; i++) {
+        methinfo = xmlrpc_array_get_item(env, methlist, i);
+        XMLRPC_ASSERT_ENV_OK(env);
+        
+        /* Call our method. */
+        xmlrpc_env_clean(&env2);
+        xmlrpc_env_init(&env2);
+        result = call_one_method(&env2, registry, methinfo);
+        
+        /* Turn any fault into a structure. */
+        if (env2.fault_occurred) {
+            XMLRPC_ASSERT(result == NULL);
+            result = 
+                xmlrpc_build_value(env, "{s:i,s:s}",
+                                   "faultCode", (xmlrpc_int32) env2.fault_code,
+                                   "faultString", env2.fault_string);
+            XMLRPC_FAIL_IF_FAULT(env);
+        }
+        
+        /* Append this method result to our master array. */
+        xmlrpc_array_append_item(env, results, result);
+        xmlrpc_DECREF(result);
+        result = NULL;
+        XMLRPC_FAIL_IF_FAULT(env);
+    }
+
+ cleanup:
+    xmlrpc_env_clean(&env2);
+    if (result)
+        xmlrpc_DECREF(result);
+    if (env->fault_occurred) {
+        if (results)
+            xmlrpc_DECREF(results);
+        return NULL;
+    }
+    return results;
+}
+
+
+
+/*=========================================================================
+**  system.listMethods
+**=========================================================================
+**  List all available methods by name.
+*/
+
+static char *listMethods_help =
+"Return an array of all available XML-RPC methods on this server.";
+
+static xmlrpc_value *
+system_listMethods(xmlrpc_env *env,
+                   xmlrpc_value *param_array,
+                   void *user_data) {
+
+    xmlrpc_registry *registry;
+    xmlrpc_value *method_names, *method_name, *method_info;
+    size_t size, i;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_VALUE_OK(param_array);
+    XMLRPC_ASSERT_PTR_OK(user_data);
+
+    /* Error-handling preconditions. */
+    method_names = NULL;
+
+    /* Turn our arguments into something more useful. */
+    registry = (xmlrpc_registry*) user_data;
+    xmlrpc_parse_value(env, param_array, "()");
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+    /* Make sure we're allowed to introspect. */
+    if (!registry->_introspection_enabled)
+        XMLRPC_FAIL(env, XMLRPC_INTROSPECTION_DISABLED_ERROR,
+                    "Introspection disabled for security reasons");
+    
+    /* Iterate over all the methods in the registry, adding their names
+    ** to a list. */
+    method_names = xmlrpc_build_value(env, "()");
+    XMLRPC_FAIL_IF_FAULT(env);
+    size = xmlrpc_struct_size(env, registry->_methods);
+    XMLRPC_FAIL_IF_FAULT(env);
+    for (i = 0; i < size; i++) {
+        xmlrpc_struct_get_key_and_value(env, registry->_methods, i,
+                                        &method_name, &method_info);
+        XMLRPC_FAIL_IF_FAULT(env);
+        xmlrpc_array_append_item(env, method_names, method_name);
+        XMLRPC_FAIL_IF_FAULT(env);
+    }
+
+ cleanup:
+    if (env->fault_occurred) {
+        if (method_names)
+            xmlrpc_DECREF(method_names);
+        return NULL;
+    }
+    return method_names;
+}
+
+
+
+/*=========================================================================
+**  system.methodHelp
+**=========================================================================
+**  Get the help string for a particular method.
+*/
+
+static char *methodHelp_help =
+"Given the name of a method, return a help string.";
+
+static xmlrpc_value *
+system_methodHelp(xmlrpc_env *env,
+                  xmlrpc_value *param_array,
+                  void *user_data) {
+
+    xmlrpc_registry *registry;
+    char *method_name;
+    xmlrpc_value *ignored1, *ignored2, *ignored3, *help;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_VALUE_OK(param_array);
+    XMLRPC_ASSERT_PTR_OK(user_data);
+
+    /* Turn our arguments into something more useful. */
+    registry = (xmlrpc_registry*) user_data;
+    xmlrpc_parse_value(env, param_array, "(s)", &method_name);
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+    /* Make sure we're allowed to introspect. */
+    if (!registry->_introspection_enabled)
+        XMLRPC_FAIL(env, XMLRPC_INTROSPECTION_DISABLED_ERROR,
+                    "Introspection disabled for security reasons");
+    
+    /* Get our documentation string. */
+    xmlrpc_parse_value(env, registry->_methods, "{s:(VVVV*),*}",
+                       method_name, &ignored1, &ignored2, &ignored3, &help);
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+ cleanup:
+    if (env->fault_occurred)
+        return NULL;
+    xmlrpc_INCREF(help);
+    return help;
+}
+
+
+
+/*=========================================================================
+**  system.methodSignature
+**=========================================================================
+**  Return an array of arrays describing possible signatures for this
+**  method.
+**
+**  XXX - This is the ugliest function in the entire library.
+*/
+
+static char *methodSignature_help =
+"Given the name of a method, return an array of legal signatures. "
+"Each signature is an array of strings. The first item of each signature "
+"is the return type, and any others items are parameter types.";
+
+static char *bad_sig_str =
+"Application has incorrect method signature information";
+
+#define BAD_SIG(env) \
+    XMLRPC_FAIL((env), XMLRPC_INTERNAL_ERROR, bad_sig_str);
+
+static xmlrpc_value *
+system_methodSignature(xmlrpc_env *env,
+                       xmlrpc_value *param_array,
+                       void *user_data) {
+
+    xmlrpc_registry *registry;
+    char *method_name;
+    xmlrpc_value *ignored1, *ignored2, *ignored3;
+    xmlrpc_value *item, *current, *result;
+    int at_sig_start;
+    char *sig, *code;
+
+    XMLRPC_ASSERT_ENV_OK(env);
+    XMLRPC_ASSERT_VALUE_OK(param_array);
+    XMLRPC_ASSERT_PTR_OK(user_data);
+
+    /* Error-handling preconditions. */
+    item = current = result = NULL;
+
+    /* Turn our arguments into something more useful. */
+    registry = (xmlrpc_registry*) user_data;
+    xmlrpc_parse_value(env, param_array, "(s)", &method_name);
+    XMLRPC_FAIL_IF_FAULT(env);
+
+    /* Make sure we're allowed to introspect. */
+    if (!registry->_introspection_enabled)
+        XMLRPC_FAIL(env, XMLRPC_INTROSPECTION_DISABLED_ERROR,
+                    "Introspection disabled for security reasons");
+    
+    /* Get our signature string. */
+    xmlrpc_parse_value(env, registry->_methods, "{s:(VVsV*),*}",
+                       method_name, &ignored1, &ignored2, &sig, &ignored3);
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+    if (sig[0] == '?' && sig[1] == '\0') {
+        /* No signature supplied. */
+        result = xmlrpc_build_value(env, "s", "undef");
+        XMLRPC_FAIL_IF_FAULT(env);
+    } else {
+        /* Build an array of arrays. */
+        current = xmlrpc_build_value(env, "()");
+        XMLRPC_FAIL_IF_FAULT(env);
+        result = xmlrpc_build_value(env, "(V)", current);
+        XMLRPC_FAIL_IF_FAULT(env);
+        at_sig_start = 1;
+        
+        do {
+        next_loop:
+            
+            /* Process the current code. */
+            switch (*(sig++)) {
+            case 'i': code = "int"; break;
+            case 'b': code = "boolean"; break;
+            case 'd': code = "double"; break;
+            case 's': code = "string"; break;
+            case '8': code = "dateTime.iso8601"; break;
+            case '6': code = "base64"; break;
+            case 'S': code = "struct"; break;
+            case 'A': code = "array"; break;
+                
+            case ',':
+                /* Start a new signature array. */
+                if (at_sig_start)
+                    BAD_SIG(env);
+                xmlrpc_DECREF(current);
+                current = xmlrpc_build_value(env, "()");
+                XMLRPC_FAIL_IF_FAULT(env);
+                xmlrpc_array_append_item(env, result, current);
+                XMLRPC_FAIL_IF_FAULT(env);
+                at_sig_start = 1;
+                goto next_loop;
+                
+            default:
+            BAD_SIG(env);
+            }
+            
+            /* Append the appropriate string to our current signature. */
+            item = xmlrpc_build_value(env, "s", code);
+            XMLRPC_FAIL_IF_FAULT(env);
+            xmlrpc_array_append_item(env, current, item);
+            xmlrpc_DECREF(item);
+            item = NULL;
+            XMLRPC_FAIL_IF_FAULT(env);
+            
+            /* Advance to the next code, and skip over ':' if necessary. */
+            if (at_sig_start) {
+                if (*sig != ':')
+                    BAD_SIG(env);
+                sig++;
+                at_sig_start = 0;
+            }
+            
+        } while (*sig != '\0');
+    }
+    
+ cleanup:
+    if (item)
+        xmlrpc_DECREF(item);
+    if (current)
+        xmlrpc_DECREF(current);
+    if (env->fault_occurred) {
+        if (result)
+            xmlrpc_DECREF(result);
+        return NULL;
+    }
+    return result;
+}
+
+
+
+/*=========================================================================
+**  install_system_methods
+**=========================================================================
+**  Install the standard methods under system.*.
+**  This particular function is highly experimental, and may disappear
+**  without warning.
+*/
+
+static void
+install_system_methods(xmlrpc_env *env, xmlrpc_registry *registry) {
+
+    xmlrpc_registry_add_method_w_doc(env, registry, NULL,
+                                     "system.listMethods",
+                                     &system_listMethods, registry,
+                                     "A:", listMethods_help);
+    XMLRPC_FAIL_IF_FAULT(env);
+    xmlrpc_registry_add_method_w_doc(env, registry, NULL,
+                                     "system.methodSignature",
+                                     &system_methodSignature, registry,
+                                     "A:s", methodSignature_help);
+    XMLRPC_FAIL_IF_FAULT(env);
+    xmlrpc_registry_add_method_w_doc(env, registry, NULL,
+                                     "system.methodHelp",
+                                     &system_methodHelp, registry,
+                                     "s:s", methodHelp_help);
+    XMLRPC_FAIL_IF_FAULT(env);
+    xmlrpc_registry_add_method_w_doc(env, registry, NULL,
+                                     "system.multicall",
+                                     &system_multicall, registry,
+                                     "A:A", multicall_help);
+    XMLRPC_FAIL_IF_FAULT(env);
+    
+ cleanup:
+    return;
+}