X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=mon%2Fmons_handlers.c;h=b546b89f82d603b3263b149d3bc60cfbb0d6e6b5;hb=733b18697117cbc63ab3d9e44510c9850916ec90;hp=68abd4858c5910626e2d0636842ffd382bbdc24a;hpb=3d175240ef0a8e0b465994e881ef98548a39091a;p=trust_router.git diff --git a/mon/mons_handlers.c b/mon/mons_handlers.c index 68abd48..b546b89 100644 --- a/mon/mons_handlers.c +++ b/mon/mons_handlers.c @@ -34,55 +34,190 @@ /* Handlers for monitoring requests */ +#include + #include #include -#include "mons_handlers.h" - -typedef MON_RESP *(MONS_HANDLER_FUNC)(TALLOC_CTX *, MONS_INSTANCE *, MON_REQ *); +#include -/* Prototypes for the dispatch table */ -static MON_RESP *mons_handle_reconfigure(TALLOC_CTX *mem_ctx, MONS_INSTANCE *mons, MON_REQ *req); +/* Static Prototypes */ +static int dispatch_entry_matches(MONS_DISPATCH_TABLE_ENTRY *e, MON_CMD command, MON_OPT_TYPE opt_type); +static MONS_HANDLER_FUNC *mons_find_handler(MONS_INSTANCE *mons, MON_CMD cmd, MON_OPT_TYPE opt_type); +static void request_helper(void *element, void *data); -struct dispatch_table_entry { +struct request_helper_data { MON_CMD command; - MONS_HANDLER_FUNC *handler; -}; - -static struct dispatch_table_entry dispatch_table[] = { - {MON_CMD_SHOW, mons_handle_show}, - {MON_CMD_RECONFIGURE, mons_handle_reconfigure}, - {MON_CMD_UNKNOWN} /* Must be the last entry in the table */ + MON_OPT_TYPE opt_type; + json_t *payload; }; /** * Call the appropriate handler for a request * + * TODO: report errors from handlers + * * @return a MON_RESP structure or null if there was a processing error */ MON_RESP *mons_handle_request(TALLOC_CTX *mem_ctx, MONS_INSTANCE *mons, MON_REQ *req) { - struct dispatch_table_entry *entry = dispatch_table; + MON_RESP *resp = NULL; + json_t *payload = NULL; + struct request_helper_data cookie; + size_t ii = 0; tr_debug("mons_handle_request: Handling a request"); - /* Find the handler */ - while ((entry->command != req->command) && (entry->command != MON_CMD_UNKNOWN)) { - entry++; + /* Start off by allocating our response with a generic error message */ + resp = mon_resp_new(mem_ctx, + MON_RESP_ERROR, + "Error processing show request", + NULL); + if (resp == NULL) { + /* we can't respond, just return */ + tr_crit("mons_handle_request: Error allocating response structure."); + goto cleanup; + } + + /* Now get a JSON object for our return payload */ + payload = json_object(); + if (payload == NULL) { + tr_crit("mons_handle_request: Error allocating response payload."); + goto cleanup; /* This will return the generic error message set earlier */ + } + + /* Now call handlers */ + cookie.command = req->command; + cookie.payload = payload; /* borrowed reference */ + + if (mon_req_opt_count(req) == 0) { + /* call every handler that matches the command */ + cookie.opt_type = OPT_TYPE_ANY; + g_ptr_array_foreach(mons->handlers, request_helper, &cookie); + } else { + /* call only those handlers that match an option */ + for (ii=0; ii < mon_req_opt_count(req); ii++) { + cookie.opt_type = mon_req_opt_index(req, ii)->type; + /* Loop over all handlers - we know we can only have one match for each opt type */ + g_ptr_array_foreach(mons->handlers, request_helper, &cookie); + } + } + + /* If we get here, then we successfully processed the request. Return a successful reply. */ + if (mon_resp_set_message(resp, "success") == 0) { + /* Failed to set the response message to success - fail ironically */ + tr_crit("mons_handle_request: Error setting response message to 'success'."); + goto cleanup; + } + + /* Attach the accumulated payload to the response */ + if (json_object_size(payload) > 0) + mon_resp_set_payload(resp, payload); + + resp->code = MON_RESP_SUCCESS; /* at last... */ + tr_debug("mons_handle_request: Successfully processed request."); + +cleanup: + if (payload) + json_decref(payload); + return resp; +} + +/** + * Register a handler for a command/option combination + * + * @param mons + * @param cmd + * @param opt_type + * @param f + * @param cookie + * @return + */ +MON_RC mons_register_handler(MONS_INSTANCE *mons, + MON_CMD cmd, + MON_OPT_TYPE opt_type, + MONS_HANDLER_FUNC *f, + void *cookie) +{ + MONS_DISPATCH_TABLE_ENTRY *entry = NULL; + + if (mons_find_handler(mons, cmd, opt_type) != NULL) { + return MON_ERROR; } - /* See if we found a handler */ - if (entry->command == MON_CMD_UNKNOWN) { - tr_info("mons_handle_request: Unknown or unsupported monitoring request received"); - return NULL; + /* Put these in the mons talloc context so we don't have to muck about with + * a free function for the GPtrArray */ + entry = talloc(mons, MONS_DISPATCH_TABLE_ENTRY); + if (entry == NULL) { + return MON_NOMEM; } + entry->command = cmd; + entry->opt_type = opt_type; + entry->handler = f; + entry->cookie = cookie; - /* Call the handler */ - tr_debug("mons_handle_request: Calling handler for %s command", mon_cmd_to_string(entry->command)); - return entry->handler(mem_ctx, mons, req); + g_ptr_array_add(mons->handlers, entry); + return MON_SUCCESS; } -static MON_RESP *mons_handle_reconfigure(TALLOC_CTX *mem_ctx, MONS_INSTANCE *mons, MON_REQ *req) +/** + * Two table entries match if none of the commands or opt_types are unknown, + * if the commands match, and if the opt types either match or at least one is + * OPT_TYPE_ANY. + * + * No comparison of the handler pointer is included. + * + * @return 1 if the two match, 0 if not + */ +static int dispatch_entry_matches(MONS_DISPATCH_TABLE_ENTRY *e, + MON_CMD command, + MON_OPT_TYPE opt_type) +{ + if ((command == MON_CMD_UNKNOWN) || (opt_type == OPT_TYPE_UNKNOWN)) + return 0; /* request is invalid */ + + if ((e->command == MON_CMD_UNKNOWN) || (e->opt_type == OPT_TYPE_UNKNOWN)) + return 0; /* e1 is invalid */ + + if (e->command != command) + return 0; /* commands do not match */ + + if (e->opt_type == opt_type) + return 1; /* exact match */ + + if ( (e->opt_type == OPT_TYPE_ANY) || (opt_type == OPT_TYPE_ANY) ) + return 1; /* one is a wildcard */ + + return 0; /* commands matched but opt_types did not */ +} + +static MONS_HANDLER_FUNC *mons_find_handler(MONS_INSTANCE *mons, MON_CMD cmd, MON_OPT_TYPE opt_type) { + guint index; + + for (index=0; index < mons->handlers->len; index++) { + if (dispatch_entry_matches(g_ptr_array_index(mons->handlers, index), cmd, opt_type)) + return g_ptr_array_index(mons->handlers, index); + } return NULL; } + +/** + * This calls every request handler that matches a command/opt_type, + * gathering their results. + * + * @param element + * @param data + */ +static void request_helper(void *element, void *data) +{ + MONS_DISPATCH_TABLE_ENTRY *entry = talloc_get_type_abort(element, MONS_DISPATCH_TABLE_ENTRY); + struct request_helper_data *helper_data = data; + + if (dispatch_entry_matches(entry, helper_data->command, helper_data->opt_type)) { + json_object_set(helper_data->payload, + mon_opt_type_to_string(entry->opt_type), + entry->handler(entry->cookie)); + } +} +