path: root/epan/wslua/wslua_pref.c

/*
 * wslua_pref.c
 *
 * Wireshark's interface to the Lua Programming Language
 *
 * (c) 2006, Luis E. Garcia Ontanon <luis@ontanon.org>
 * (c) 2008, Balint Reczey <balint.reczey@ericsson.com>
 * (c) 2011, Stig Bjorlykke <stig@bjorlykke.org>
 * (c) 2014, Hadriel Kaplan <hadrielk@yahoo.com>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include "wslua.h"

/* WSLUA_CONTINUE_MODULE Proto */


WSLUA_CLASS_DEFINE(Pref,NOP,NOP); /* A preference of a Protocol. */

static range_t* get_range(lua_State *L, int idx_r, int idx_m);

static enum_val_t* get_enum(lua_State *L, int idx)
{
    double seq;
    const gchar *str1, *str2;
    enum_val_t *ret, last = {NULL, NULL, -1};
    GArray* es = g_array_new(TRUE,TRUE,sizeof(enum_val_t));

    luaL_checktype(L, idx, LUA_TTABLE);
    lua_pushnil(L);  /* first key */

    while (lua_next(L, idx)) {
        enum_val_t e = {NULL, NULL, -1};

        luaL_checktype(L, -1, LUA_TTABLE);
        lua_pushnil(L);
        lua_next(L, -2);
        if (! lua_isstring(L,-1)) {
            luaL_argerror(L,idx,"First value of an enum table must be string");
            g_array_free(es,TRUE);
            return NULL;
        }
        str1 = lua_tostring(L, -1);

        lua_pop(L, 1);
        lua_next(L, -2);
        if (! lua_isstring(L,-1)) {
            luaL_argerror(L,idx,"Second value of an enum table must be string");
            g_array_free(es,TRUE);
            return NULL;
        }
        str2 = lua_tostring(L, -1);

        lua_pop(L, 1);
        lua_next(L, -2);
        if (! lua_isnumber(L,-1)) {
            luaL_argerror(L,idx,"Third value of an enum table must be an integer");
            g_array_free(es,TRUE);
            return NULL;
        }
        seq = lua_tonumber(L, -1);

        e.name = g_strdup(str1);
        e.description = g_strdup(str2);
        e.value = (guint32)seq;

        g_array_append_val(es,e);

        lua_pop(L, 3);  /* removes 'value'; keeps 'key' for next iteration */
    }

    g_array_append_val(es,last);

    ret = (enum_val_t*)(void*)es->data;

    g_array_free(es,FALSE);

    return ret;
}

static int new_pref(lua_State* L, pref_type_t type) {
    const gchar* label = luaL_optstring(L,1,NULL);
    const gchar* descr = luaL_optstring(L,3,"");

    Pref pref = (wslua_pref_t *)g_malloc0(sizeof(wslua_pref_t));
    pref->label = g_strdup(label);
    pref->desc = g_strdup(descr);
    pref->type = type;

    switch(type) {
        case PREF_BOOL: {
            gboolean def = wslua_toboolean(L,2);
            pref->value.b = def;
            break;
        }
        case PREF_UINT: {
            guint32 def = wslua_optgint32(L,2,0);
            pref->value.u = def;
            break;
        }
        case PREF_STRING: {
            gchar* def = g_strdup(luaL_optstring(L,2,""));
            /*
             * prefs_register_string_preference() assumes that the
             * variable for the preference points to a static
             * string that is the initial (default) value of the
             * preference.  It makes a g_strdup()ed copy of that
             * string, and assigns a pointer to that string to
             * the variable.
             *
             * Our default string is *not* a static string, it's
             * a g_strdup()ed copy of a string from Lua, so it would
             * be leaked.
             *
             * We save it in info.default_s, as well as setting the
             * initial value of the preference from it, so that we
             * can free it after prefs_register_string_preference()
             * returns.
             *
             * (Would that we were programming in a language where
             * the details of memory management were handled by the
             * compiler and language support....)
             */
            pref->value.s = def;
            pref->info.default_s = def;
            break;
        }
        case PREF_ENUM: {
            guint32 def = wslua_optgint32(L,2,0);
            enum_val_t *enum_val = get_enum(L,4);
            gboolean radio = wslua_toboolean(L,5);
            pref->value.e = def;
            pref->info.enum_info.enumvals = enum_val;
            pref->info.enum_info.radio_buttons = radio;
            break;
        }
        case PREF_RANGE: {
            range_t *range = get_range(L,2,4);
            guint32 max = wslua_optgint32(L,4,0);
            pref->value.r = range;
            pref->info.max_value = max;
            break;
        }
        case PREF_STATIC_TEXT: {
            /* This is just a static text. */
            break;
        }
        default:
            g_assert_not_reached();
            break;

    }

    pushPref(L,pref);
    return 1;
}

WSLUA_CONSTRUCTOR Pref_bool(lua_State* L) {
    /* Creates a boolean preference to be added to a `Proto.prefs` Lua table. */
#define WSLUA_ARG_Pref_bool_LABEL 1 /* The Label (text in the right side of the
                                       preference input) for this preference. */
#define WSLUA_ARG_Pref_bool_DEFAULT 2 /* The default value for this preference. */
#define WSLUA_ARG_Pref_bool_DESCR 3 /* A description of what this preference is. */
    return new_pref(L,PREF_BOOL);
}

WSLUA_CONSTRUCTOR Pref_uint(lua_State* L) {
    /* Creates an (unsigned) integer preference to be added to a `Proto.prefs` Lua table. */
#define WSLUA_ARG_Pref_uint_LABEL 1 /* The Label (text in the right side of the
                                       preference input) for this preference. */
#define WSLUA_ARG_Pref_uint_DEFAULT 2 /* The default value for this preference. */
#define WSLUA_ARG_Pref_uint_DESCR 3 /* A description of what this preference is. */
    return new_pref(L,PREF_UINT);
}

WSLUA_CONSTRUCTOR Pref_string(lua_State* L) {
    /* Creates a string preference to be added to a `Proto.prefs` Lua table. */
#define WSLUA_ARG_Pref_string_LABEL 1 /* The Label (text in the right side of the
                                         preference input) for this preference. */
#define WSLUA_ARG_Pref_string_DEFAULT 2 /* The default value for this preference. */
#define WSLUA_ARG_Pref_string_DESCR 3 /* A description of what this preference is. */
    return new_pref(L,PREF_STRING);
}

WSLUA_CONSTRUCTOR Pref_enum(lua_State* L) {
    /* Creates an enum preference to be added to a `Proto.prefs` Lua table. */
#define WSLUA_ARG_Pref_enum_LABEL 1 /* The Label (text in the right side of the
                                       preference input) for this preference. */
#define WSLUA_ARG_Pref_enum_DEFAULT 2 /* The default value for this preference. */
#define WSLUA_ARG_Pref_enum_DESCR 3 /* A description of what this preference is. */
#define WSLUA_ARG_Pref_enum_ENUM 4 /* An enum Lua table. */
#define WSLUA_ARG_Pref_enum_RADIO 5 /* Radio button (true) or Combobox (false). */
    return new_pref(L,PREF_ENUM);
}

WSLUA_CONSTRUCTOR Pref_range(lua_State* L) {
    /* Creates a range preference to be added to a `Proto.prefs` Lua table. */
#define WSLUA_ARG_Pref_range_LABEL 1 /* The Label (text in the right side of the preference
                                        input) for this preference. */
#define WSLUA_ARG_Pref_range_DEFAULT 2 /* The default value for this preference, e.g., "53",
                                          "10-30", or "10-30,53,55,100-120". */
#define WSLUA_ARG_Pref_range_DESCR 3 /* A description of what this preference is. */
#define WSLUA_ARG_Pref_range_MAX 4 /* The maximum value. */
    return new_pref(L,PREF_RANGE);
}

WSLUA_CONSTRUCTOR Pref_statictext(lua_State* L) {
    /* Creates a static text string to be added to a `Proto.prefs` Lua table. */
#define WSLUA_ARG_Pref_statictext_LABEL 1 /* The static text. */
#define WSLUA_ARG_Pref_statictext_DESCR 2 /* The static text description. */
    return new_pref(L,PREF_STATIC_TEXT);
}

static range_t* get_range(lua_State *L, int idx_r, int idx_m)
{
    static range_t *ret = NULL;
    const gchar *pattern = luaL_checkstring(L, idx_r);

    switch (range_convert_str(&ret, pattern, wslua_togint32(L, idx_m))) {
        case CVT_NO_ERROR:
          break;
        case CVT_SYNTAX_ERROR:
          WSLUA_ARG_ERROR(Pref_range,DEFAULT,"syntax error in default range");
          return 0;
        case CVT_NUMBER_TOO_BIG:
          WSLUA_ARG_ERROR(Pref_range,DEFAULT,"value too large in default range");
          return 0;
        default:
          WSLUA_ARG_ERROR(Pref_range,DEFAULT,"unknown error in default range");
          return 0;
    }

    return ret;
}

/* Gets registered as metamethod automatically by WSLUA_REGISTER_CLASS/META */
static int Pref__gc(lua_State* L) {
    Pref pref = toPref(L,1);

    /*
     * Only free never-registered and registered-and-then-deregistered
     * Prefs; those have a null name pointer.
     *
     * If this has never been registered, it obviously has not been
     * deregistered, so, if it's a string preference, we need to
     * free the initial value in pref->info.default_s.  We don't
     * need to free the current value, as that's the same string
     * as the initial value.
     *
     * If this has been registred and deregistered, and the current
     * value was allocated, it was freed when it was deregistered,
     * so we don't need to free it.  If it's a string preference,
     * the initial value was freed and the pointer to it set to
     * NULL, so we can still call g_free() on it, as that won't
     * do anything.
     */
    if (! pref->name) {
        g_free(pref->label);
        g_free(pref->desc);
        switch (pref->type) {
            case PREF_STRING:
                /*
                 * Free the initial string value; if it's not NULL, that
                 * means this is a never-registered preference, so the
                 * initial value hasn't been freed.
                 */
                g_free(pref->info.default_s);
                break;
            case PREF_ENUM: {
                /*
                 * Free the enum values allocated in get_enum().
                 */
                const enum_val_t *enum_valp = pref->info.enum_info.enumvals;
                while (enum_valp->name) {
                    g_free((char *)enum_valp->name);
                    g_free((char *)enum_valp->description);
                    enum_valp++;
                }
                g_free ((enum_val_t *)pref->info.enum_info.enumvals);
                break;
            }
            default:
                break;
        }
        g_free(pref);
    }

    return 0;
}

WSLUA_METHODS Pref_methods[] = {
    WSLUA_CLASS_FNREG(Pref,bool),
    WSLUA_CLASS_FNREG(Pref,uint),
    WSLUA_CLASS_FNREG(Pref,string),
    WSLUA_CLASS_FNREG(Pref,enum),
    WSLUA_CLASS_FNREG(Pref,range),
    WSLUA_CLASS_FNREG(Pref,statictext),
    { NULL, NULL }
};

WSLUA_META Pref_meta[] = {
    { NULL, NULL }
};


WSLUA_REGISTER Pref_register(lua_State* L) {
    WSLUA_REGISTER_CLASS(Pref);
    return 0;
}

WSLUA_CLASS_DEFINE(Prefs,NOP,NOP); /* The table of preferences of a protocol. */

WSLUA_METAMETHOD Prefs__newindex(lua_State* L) {
    /* Creates a new preference. */
#define WSLUA_ARG_Prefs__newindex_NAME 2 /* The abbreviation of this preference. */
#define WSLUA_ARG_Prefs__newindex_PREF 3 /* A valid but still unassigned Pref object. */

    Pref prefs_p = checkPrefs(L,1);
    const gchar* name = luaL_checkstring(L,WSLUA_ARG_Prefs__newindex_NAME);
    Pref pref = checkPref(L,WSLUA_ARG_Prefs__newindex_PREF);
    Pref p;
    const gchar *c;

    if (! prefs_p ) return 0;

    if (! pref ) {
        WSLUA_ARG_ERROR(Prefs__newindex,PREF,"must be a valid Pref");
        return 0;
    }

    if (pref->name) {
        WSLUA_ARG_ERROR(Prefs__newindex,NAME,"cannot change existing preference");
        return 0;
    }

    if (pref->proto) {
        WSLUA_ARG_ERROR(Prefs__newindex,PREF,"cannot be added to more than one protocol");
        return 0;
    }

    p = prefs_p;

    do {
        if ( p->name && g_str_equal(p->name,name) ) {
            luaL_error(L,"a preference named %s exists already",name);
            return 0;
        }
        /*
         * Make sure that only lower-case ASCII letters, numbers,
         * underscores, and dots appear in the preference name.
         */
        for (c = name; *c != '\0'; c++) {
            if (!g_ascii_islower(*c) && !g_ascii_isdigit(*c) && *c != '_' && *c != '.')
            {
                luaL_error(L,"illegal preference name \"%s\", only lower-case ASCII letters, "
                             "numbers, underscores and dots may be used", name);
                return 0;
            }
        }

        if ( ! p->next) {
            p->next = pref;
            pref->name = g_strdup(name);

            if (!pref->label)
                pref->label = g_strdup(name);

            if (!prefs_p->proto->prefs_module) {
                prefs_p->proto->prefs_module = prefs_register_protocol(prefs_p->proto->hfid,
                                                                       wslua_prefs_changed);
            }

            switch(pref->type) {
                case PREF_BOOL:
                    prefs_register_bool_preference(prefs_p->proto->prefs_module,
                                                   pref->name,
                                                   pref->label,
                                                   pref->desc,
                                                   &(pref->value.b));
                    break;
                case PREF_UINT:
                    prefs_register_uint_preference(prefs_p->proto->prefs_module,
                                                   pref->name,
                                                   pref->label,
                                                   pref->desc,
                                                   10,
                                                   &(pref->value.u));
                    break;
                case PREF_STRING:
                    prefs_register_string_preference(prefs_p->proto->prefs_module,
                                                     pref->name,
                                                     pref->label,
                                                     pref->desc,
                                                     (const char **)(&(pref->value.s)));
                    /*
                     * We're finished with the initial string value; see
                     * the comment in new_pref().
                     */
                    g_free(pref->info.default_s);
                    pref->info.default_s = NULL;
                    break;
                case PREF_ENUM:
                    prefs_register_enum_preference(prefs_p->proto->prefs_module,
                                                     pref->name,
                                                     pref->label,
                                                     pref->desc,
                                                     &(pref->value.e),
                                                     pref->info.enum_info.enumvals,
                                                     pref->info.enum_info.radio_buttons);
                    break;
                case PREF_RANGE:
                    prefs_register_range_preference(prefs_p->proto->prefs_module,
                                                     pref->name,
                                                     pref->label,
                                                     pref->desc,
                                                     &(pref->value.r),
                                                     pref->info.max_value);
                    break;
                case PREF_STATIC_TEXT:
                    prefs_register_static_text_preference(prefs_p->proto->prefs_module,
                                                     pref->name,
                                                     pref->label,
                                                     pref->desc);
                    break;
                default:
                    WSLUA_ERROR(Prefs__newindex,"Unknow Pref type");
                    break;
            }

            pref->proto = p->proto;

            WSLUA_RETURN(0);
        }
    } while (( p = p->next ));

    luaL_error(L,"this should not happen!");

    WSLUA_RETURN(0);
}

WSLUA_METAMETHOD Prefs__index(lua_State* L) {
    /* Get the value of a preference setting. */
#define WSLUA_ARG_Prefs__index_NAME 2 /* The abbreviation of this preference. */

    Pref prefs_p = checkPrefs(L,1);
    const gchar* name = luaL_checkstring(L,WSLUA_ARG_Prefs__index_NAME);

    if (! prefs_p ) return 0;

    if (!prefs_p->next) {
        luaL_error(L,"No preference is registered yet");
        return 0;
    }

    prefs_p = prefs_p->next;

    do {
        if ( g_str_equal(prefs_p->name,name) ) {
            switch (prefs_p->type) {
                case PREF_BOOL: lua_pushboolean(L, prefs_p->value.b); break;
                case PREF_UINT: lua_pushnumber(L,(lua_Number)prefs_p->value.u); break;
                case PREF_STRING: lua_pushstring(L,prefs_p->value.s); break;
                case PREF_ENUM: lua_pushnumber(L,(lua_Number)prefs_p->value.e); break;
                case PREF_RANGE:
                    {
                    char *push_str = range_convert_range(NULL, prefs_p->value.r);
                    lua_pushstring(L, push_str);
                    wmem_free(NULL, push_str);
                    }
                    break;
                default: WSLUA_ERROR(Prefs__index,"Unknow Pref type"); return 0;
            }
            WSLUA_RETURN(1); /* The current value of the preference. */
        }
    } while (( prefs_p = prefs_p->next ));

    WSLUA_ARG_ERROR(Prefs__index,NAME,"no preference named like this");
    return 0;
}

/* Gets registered as metamethod automatically by WSLUA_REGISTER_CLASS/META */
static int Prefs__gc(lua_State* L _U_) {
    /* do NOT free Prefs, it's a static part of Proto */
    return 0;
}

WSLUA_META Prefs_meta[] = {
    WSLUA_CLASS_MTREG(Prefs,newindex),
    WSLUA_CLASS_MTREG(Prefs,index),
    { NULL, NULL }
};

WSLUA_REGISTER Prefs_register(lua_State* L) {
    WSLUA_REGISTER_META(Prefs);
    return 0;
}


/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */