diff options
Diffstat (limited to 'epan/wslua/wslua_file_common.c')
-rw-r--r-- | epan/wslua/wslua_file_common.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/epan/wslua/wslua_file_common.c b/epan/wslua/wslua_file_common.c new file mode 100644 index 0000000..ab0f2a6 --- /dev/null +++ b/epan/wslua/wslua_file_common.c @@ -0,0 +1,196 @@ +/* + * wslua_file_common.c + * + * Wireshark's interface to the Lua Programming Language + * for file handling related source file internal functions. + * + * (c) 2014, Hadriel Kaplan <hadrielk@yahoo.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +/************ + * The following is for handling private data for the duration of the file + * read_open/read/close cycle, or write_open/write/write_close cycle. + * In other words it handles the "priv" member of wtap and wtap_dumper, + * but for the Lua script's use. A Lua script can set a Lua table + * to CaptureInfo/CaptureInfoConst and have it saved and retrievable this way. + * We need to offer that, because there needs to be a way for Lua scripts + * to save state for a given file's operations cycle. Since there can be + * two files opened at the same time for the same Lua script (due to reload + * and other such events), the script can't just have one file state. + */ +#include "config.h" + +#include "wslua_file_common.h" + + +/* create and set the wtap->priv private data for the file instance */ +void create_wth_priv(lua_State* L, wtap *wth) { + file_priv_t *priv = g_new(file_priv_t, 1); + + if (wth->priv != NULL) { + g_free(priv); + luaL_error(L, "Cannot create wtap private data because there already is private data"); + return; + } + priv->table_ref = LUA_NOREF; + wth->priv = (void*) priv; +} + +/* gets the private data table from wtap */ +int get_wth_priv_table_ref(lua_State* L, wtap *wth) { + file_priv_t *priv = (file_priv_t*) wth->priv; + + if (!priv) { + /* shouldn't be possible */ + luaL_error(L, "Cannot get wtap private data: it is null"); + return LUA_NOREF; + } + + /* the following might push a nil, but that's ok */ + lua_rawgeti(L, LUA_REGISTRYINDEX, priv->table_ref); + + return 1; +} + +/* sets the private data to wtap - the table is presumed on top of stack */ +int set_wth_priv_table_ref(lua_State* L, wtap *wth) { + file_priv_t *priv = (file_priv_t*) wth->priv; + + if (!priv) { + /* shouldn't be possible */ + luaL_error(L, "Cannot get wtap private data: it is null"); + return 0; + } + + if (lua_isnil(L, -1)){ + /* user is setting it nil - ok, de-ref any previous one */ + luaL_unref(L, LUA_REGISTRYINDEX, priv->table_ref); + priv->table_ref = LUA_NOREF; + return 0; + } + + if (!lua_istable(L, -1)) { + luaL_error(L, "The private_table member can only be set to a table or nil"); + return 0; + } + + /* if we had a table already referenced, de-ref it first */ + if (priv->table_ref != LUA_NOREF) { + luaL_unref(L, LUA_REGISTRYINDEX, priv->table_ref); + } + + priv->table_ref = luaL_ref(L, LUA_REGISTRYINDEX); + + return 0; +} + +/* remove, deref, and free the wtap->priv data */ +void remove_wth_priv(lua_State* L, wtap *wth) { + file_priv_t *priv = (file_priv_t*) wth->priv; + + if (!priv) { + /* shouldn't be possible */ + luaL_error(L, "Cannot remove wtap private data: it is null"); + return; + } + + luaL_unref(L, LUA_REGISTRYINDEX, priv->table_ref); + + g_free(wth->priv); + wth->priv = NULL; +} + +/* create and set the wtap_dumper->priv private data for the file instance */ +void create_wdh_priv(lua_State* L, wtap_dumper *wdh) { + file_priv_t *priv = g_new(file_priv_t, 1); + + if (wdh->priv != NULL) { + g_free(priv); + luaL_error(L, "Cannot create wtap_dumper private data because there already is private data"); + return; + } + priv->table_ref = LUA_NOREF; + wdh->priv = (void*) priv; +} + +/* get the private data from wtap_dumper */ +int get_wdh_priv_table_ref(lua_State* L, wtap_dumper *wdh) { + file_priv_t *priv = (file_priv_t*) wdh->priv; + + if (!priv) { + /* shouldn't be possible */ + luaL_error(L, "Cannot get wtap_dumper private data: it is null"); + return LUA_NOREF; + } + + /* the following might push a nil, but that's ok */ + lua_rawgeti(L, LUA_REGISTRYINDEX, priv->table_ref); + + return 1; +} + +/* sets the private data to wtap - the table is presumed on top of stack */ +int set_wdh_priv_table_ref(lua_State* L, wtap_dumper *wdh) { + file_priv_t *priv = (file_priv_t*) wdh->priv; + + if (!priv) { + /* shouldn't be possible */ + luaL_error(L, "Cannot get wtap private data: it is null"); + return 0; + } + + if (lua_isnil(L, -1)){ + /* user is setting it nil - ok, de-ref any previous one */ + luaL_unref(L, LUA_REGISTRYINDEX, priv->table_ref); + priv->table_ref = LUA_NOREF; + return 0; + } + + if (!lua_istable(L, -1)) { + luaL_error(L, "The private_table member can only be set to a table or nil"); + return 0; + } + + /* if we had a table already referenced, de-ref it first */ + if (priv->table_ref != LUA_NOREF) { + luaL_unref(L, LUA_REGISTRYINDEX, priv->table_ref); + } + + priv->table_ref = luaL_ref(L, LUA_REGISTRYINDEX); + + return 0; +} + +/* remove and deref the wtap_dumper->priv data */ +void remove_wdh_priv(lua_State* L, wtap_dumper *wdh) { + file_priv_t *priv = (file_priv_t*) wdh->priv; + + if (!priv) { + /* shouldn't be possible */ + luaL_error(L, "Cannot remove wtap_dumper private data: it is null"); + return; + } + + luaL_unref(L, LUA_REGISTRYINDEX, priv->table_ref); + /* we do NOT free wtap_dumper's priv member - wtap_dump_close() free's it */ +} + + +/* + * Editor modelines - https://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: + */ |