/* conditions.c * Implementation for condition handler. * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include #include #include #include #include "conditions.h" #include "ws_attributes.h" /* container for condition classes */ static GHashTable *classes = NULL; /* condition data structure declaration */ struct condition{ char *class_id; void *user_data; _cnd_eval eval_func; _cnd_reset reset_func; }; /* structure used to store class functions in GHashTable */ typedef struct _cnd_class{ _cnd_constr constr_func; _cnd_destr destr_func; _cnd_eval eval_func; _cnd_reset reset_func; } _cnd_class; /* helper function prototypes */ static void _cnd_init(void); static void _cnd_find_hash_key_for_class_id(gpointer, gpointer, gpointer); condition *cnd_new(const char *class_id, ...) { va_list ap; condition *cnd = NULL; condition *cnd_ref = NULL; _cnd_class *cls = NULL; char *id = NULL; /* check if hash table is already initialized */ _cnd_init(); /* get class structure for this id */ if ((cls = (_cnd_class *)g_hash_table_lookup(classes, class_id)) == NULL) { g_warning("cnd_new: Couldn't find class ID \"%s\"", class_id); return NULL; } /* initialize the basic structure */ if ((cnd_ref = (condition *)g_malloc(sizeof(condition))) == NULL) return NULL; cnd_ref->user_data = NULL; cnd_ref->eval_func = cls->eval_func; cnd_ref->reset_func = cls->reset_func; cnd_ref->class_id = g_strdup(class_id); /* perform class specific initialization */ va_start(ap, class_id); cnd = (cls->constr_func)(cnd_ref, ap); va_end(ap); /* check for successful construction */ if (cnd == NULL) { g_free(cnd_ref); g_free(id); } return cnd; } /* END cnd_new() */ void cnd_delete(condition *cnd) { _cnd_class *cls = NULL; const char* class_id; /* check for valid pointer */ if (cnd == NULL) return; class_id = cnd->class_id; /* check if hash table is already initialized */ _cnd_init(); /* get the condition class */ cls = (_cnd_class *)g_hash_table_lookup(classes, class_id); /* call class specific destructor */ if (cls != NULL) (cls->destr_func)(cnd); /* free memory */ g_free(cnd->class_id); /* free basic structure */ g_free(cnd); } /* END cnd_delete() */ gboolean cnd_eval(condition *cnd, ...) { va_list ap; gboolean ret_val = FALSE; /* validate cnd */ if (cnd == NULL) return FALSE; /* call specific handler */ va_start(ap, cnd); ret_val = (cnd->eval_func)(cnd, ap); va_end(ap); return ret_val; } /* END cnd_eval() */ void cnd_reset(condition *cnd) { if (cnd != NULL) (cnd->reset_func)(cnd); } /* END cnd_reset() */ void* cnd_get_user_data(condition *cnd) { return cnd->user_data; } /* END cnd_get_user_data() */ void cnd_set_user_data(condition *cnd, void *user_data) { cnd->user_data = user_data; } /* END cnd_set_user_data() */ gboolean cnd_register_class(const char *class_id, _cnd_constr constr_func, _cnd_destr destr_func, _cnd_eval eval_func, _cnd_reset reset_func) { char *key = NULL; _cnd_class *cls = NULL; /* check for valid parameters */ if ((constr_func == NULL) || (destr_func == NULL) || (eval_func == NULL) || (reset_func == NULL) || (class_id == NULL)) return FALSE; /* check if hash table is already initialized */ _cnd_init(); /* check for unique class id */ if (g_hash_table_lookup(classes, class_id) != NULL) { g_warning("cnd_register_class: Duplicate class ID \"%s\"", class_id); return FALSE; } /* GHashTable keys need to be persistent for the lifetime of the hash table. Allocate memory and copy the class id which we use as key. */ key = g_strdup(class_id); /* initialize class structure */ if ((cls = (_cnd_class*)g_malloc(sizeof(_cnd_class))) == NULL) { g_free(key); return FALSE; } cls->constr_func = constr_func; cls->destr_func = destr_func; cls->eval_func = eval_func; cls->reset_func = reset_func; /* insert new class */ g_hash_table_insert(classes, key, cls); return TRUE; } /* END cnd_register_class() */ static char *pkey = NULL; void cnd_unregister_class(const char* class_id) { const char *key = (const char*)class_id; _cnd_class *cls = NULL; /* check if hash table is already initialized */ _cnd_init(); /* find the key for this class id and store it in 'pkey' */ g_hash_table_foreach(classes, _cnd_find_hash_key_for_class_id, (gpointer)key); /* find the class structure for this class id */ cls = (_cnd_class*)g_hash_table_lookup(classes, class_id); /* remove constructor from hash table */ g_hash_table_remove(classes, class_id); /* free the key */ g_free(pkey); pkey = NULL; /* free the value */ g_free(cls); } /* END cnd_unregister_class() */ /* * Initialize hash table. */ static void _cnd_init(void) { if (classes != NULL) return; /* create hash table, we use strings as keys */ classes = g_hash_table_new(g_str_hash, g_str_equal); } /* END _cnd_init() */ /* * Callback for function 'g_hash_table_foreach()'. * We don't keep references to hash table keys. Keys have memory allocated * which must be freed when they are not used anymore. This function finds * the reference to a key corresponding to a particular class id. The reference * to the key is stored in a global variable. */ void _cnd_find_hash_key_for_class_id(gpointer key, gpointer value _U_, gpointer user_data) { char *class_id = (char *)user_data; char *key_value = (char *)key; if (strcmp(class_id, key_value) == 0) pkey = key_value; } /* END _cnd_find_hash_key_for_class_id() */ /* * Editor modelines * * Local Variables: * c-basic-offset: 2 * tab-width: 8 * indent-tabs-mode: nil * End: * * ex: set shiftwidth=2 tabstop=8 expandtab: * :indentSize=2:tabSize=8:noTabs=true: */