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- fix a sure crash after an error in lua code lua_tap_draw. 

- make sure no reference to a Tvb in lua is used after the lua dissector has returned.


svn path=/trunk/; revision=17296
This commit is contained in:
Luis Ontanon 2006-02-14 01:29:55 +00:00
parent ad9da9fccb
commit 0980473a80
4 changed files with 113 additions and 62 deletions
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1
plugins/lua/lua_tap.c
View File

@ -301,6 +301,7 @@ void lua_tap_draw(void *tapdata) {
/* OK */
break;
case LUA_ERRRUN:
error = lua_tostring(tap->L,-1);
g_warning("Runtime error while calling %s.draw(): %s",tap->name,error);
break;
case LUA_ERRMEM:

171
plugins/lua/lua_tvb.c
View File

@ -26,26 +26,8 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
* XXX: TODO
*
* having Tvbs and TvbRanges have a lifetime of just the dissector callback
* but being user able to save them in global variables for later use
* every lua value created with these should be NULLified after the dissector's
* callback, pushXxx() gives back a pointer to the pointer it saves that has to be pushed
* to a queue and NULLified before returning from packet_lua.
*
* in order to do that we need to verify that every function in this file yields an
* error if the Xxx ptr it uses is NULL.
*
* the same would applies to Pinfo, Item and Tree
* Item and Tree are protected in the sense that the callbacks to these
*/
#include "packet-lua.h"
LUA_CLASS_DEFINE(Tvb,TVB,if (! *p) luaL_error(L,"null tvb"))
LUA_CLASS_DEFINE(TvbRange,TVB_RANGE,NOP)
LUA_CLASS_DEFINE(ByteArray,BYTE_ARRAY,if (! *p) luaL_argerror(L,index,"null bytearray"))
static int ByteArray_new(lua_State* L) {
@ -287,10 +269,51 @@ int ByteArray_register(lua_State* L) {
/*
* Tvb class
* Tvb & TvbRange
*
* a Tvb represents a tvbuff_t in Lua.
* a TvbRange represents a range in a tvb (tvb,offset,lenght) it's main purpose is to do bounds checking,
* it helps too simplifing argument passing to Tree. In ethereal terms this is worthless nothing
* not already done by the TVB itself. In lua's terms is necessary to avoid abusing TRY{}CATCH(){}
* via preemptive bounds checking.
*
* These lua objects have to be "NULLified after use", that is, we cannot leave pointers in the
* lua machine to a tvb or a tvbr that might exist anymore.
*
* To do so we are going to keep a pointer to every "box" in which lua has placed a pointer to our object
* and then NULLify the object lua points to.
*
* Other than that we are going to check every instance of a potentialy NULLified object before using it
* and report an error to the lua machine if it happens to be NULLified.
*/
LUA_CLASS_DEFINE(Tvb,TVB,if (! *p) luaL_error(L,"expired tvb"))
LUA_CLASS_DEFINE(TvbRange,TVB_RANGE,if (! *p) luaL_error(L,"expired tvbrange"))
GPtrArray* allocated_tvbs = NULL;
GPtrArray* allocated_tvbrs = NULL;
#define PUSH_TVB(L,t) g_ptr_array_add(allocated_tvbs,pushTvb(L,t))
#define PUSH_TVBRANGE(L,t) g_ptr_array_add(allocated_tvbs,pushTvbRange(L,t))
void clear_outstanding_tvbs(void) {
while (allocated_tvbrs->len) {
Tvb* p = (Tvb*)g_ptr_array_remove_index_fast(allocated_tvbs,0);
*p = NULL;
}
while (allocated_tvbrs->len) {
TvbRange* p = (TvbRange*)g_ptr_array_remove_index_fast(allocated_tvbrs,0);
if (p) g_free(*p);
*p = NULL;
}
}
/*
* Tvb_new_real(bytearray,name)
* Creates a new Tvb from a bytearray (adds it to the frame too)
*/
static int Tvb_new_real (lua_State *L) {
ByteArray ba = checkByteArray(L,1);
const gchar* name = luaL_optstring(L,2,"Unnamed") ;
@ -300,41 +323,31 @@ static int Tvb_new_real (lua_State *L) {
if (!ba) return 0;
if (!lua_tvb) {
/*
XXX: a tvb should only be used in the frame that created it
we need to find a way to disable those stored in Lua.
*/
luaL_error(L,"Tvb can only be used in dissectors");
luaL_error(L,"Tvbs can only be created and used in dissectors");
return 0;
}
if (! ba) return 0;
data = g_memdup(ba->data, ba->len);
tvb = tvb_new_real_data(data, ba->len,ba->len);
tvb_set_free_cb(tvb, g_free);
add_new_data_source(lua_pinfo, tvb, name);
pushTvb(L,tvb);
PUSH_TVB(L,tvb);
return 1;
}
/*
* creates a subtvb from a tvbrange
*
*/
static int Tvb_new_subset (lua_State *L) {
TvbRange tvbr = checkTvbRange(L,1);
if (! tvbr) return 0;
if (! lua_tvb ) {
/* XXX: incomplete check, a tvb should only be used in the frame that created it */
luaL_error(L,"Tvb can only be used in dissectors");
return 0;
}
if (tvb_offset_exists(tvbr->tvb, tvbr->offset + tvbr->len -1 )) {
pushTvb(L, tvb_new_subset(tvbr->tvb,tvbr->offset,tvbr->len, tvbr->len) );
PUSH_TVB(L, tvb_new_subset(tvbr->tvb,tvbr->offset,tvbr->len, tvbr->len) );
return 1;
} else {
luaL_error(L,"Out Of Bounds");
@ -342,7 +355,9 @@ static int Tvb_new_subset (lua_State *L) {
}
}
/*
* convert the bytes to string, mainly for debugging purposes (mind the ...)
*/
static int Tvb_tostring(lua_State* L) {
Tvb tvb = checkTvb(L,1);
int len;
@ -357,31 +372,26 @@ static int Tvb_tostring(lua_State* L) {
}
/*
* returns the length of a TVB
*/
static int Tvb_len(lua_State* L) {
Tvb tvb = checkTvb(L,1);
if (!tvb) return 0;
if (!lua_pinfo) {
luaL_error(L,"Tvb can only be used in dissectors");
return 0;
}
lua_pushnumber(L,tvb_length(tvb));
return 1;
}
/*
* returns the raw offset of a sub TVB
*/
static int Tvb_offset(lua_State* L) {
Tvb tvb = checkTvb(L,1);
if (!tvb) return 0;
if (!lua_pinfo) {
luaL_error(L,"Tvb can only be used in dissectors");
return 0;
}
lua_pushnumber(L,TVB_RAW_OFFSET(tvb));
return 1;
}
@ -403,6 +413,8 @@ static const luaL_reg Tvb_meta[] = {
int Tvb_register(lua_State* L) {
allocated_tvbs = g_ptr_array_new();
luaL_openlib(L, TVB, Tvb_methods, 0);
luaL_newmetatable(L, TVB);
luaL_openlib(L, 0, Tvb_meta, 0);
@ -417,6 +429,11 @@ int Tvb_register(lua_State* L) {
return 1;
}
/*
* TVB RAnge helper class
*
*/
TvbRange new_TvbRange(lua_State* L, tvbuff_t* tvb, int offset, int len) {
TvbRange tvbr;
@ -439,6 +456,9 @@ TvbRange new_TvbRange(lua_State* L, tvbuff_t* tvb, int offset, int len) {
return tvbr;
}
/*
* creates a tvbr given the triplet (tvb,offset,len)
*/
static int Tvb_range(lua_State* L) {
Tvb tvb = checkTvb(L,1);
int offset = luaL_optint(L,2,0);
@ -448,7 +468,7 @@ static int Tvb_range(lua_State* L) {
if (!tvb) return 0;
if ((tvbr = new_TvbRange(L,tvb,offset,len))) {
pushTvbRange(L,tvbr);
PUSH_TVBRANGE(L,tvbr);
return 1;
}
@ -457,17 +477,15 @@ static int Tvb_range(lua_State* L) {
}
static int TvbRange_gc(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
if (tvbr) g_free(tvbr);
return 0;
}
/*
* read access to tvbr's data
*/
static int TvbRange_get_index(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
const gchar* index = luaL_checkstring(L,2);
if (!(tvbr && index)) return 0;
if (g_str_equal(index,"offset")) {
lua_pushnumber(L,(lua_Number)tvbr->offset);
return 1;
@ -475,7 +493,7 @@ static int TvbRange_get_index(lua_State* L) {
lua_pushnumber(L,(lua_Number)tvbr->len);
return 1;
} else if (g_str_equal(index,"tvb")) {
pushTvb(L,tvbr->tvb);
PUSH_TVB(L,tvbr->tvb);
return 1;
} else {
luaL_error(L,"TvbRange has no `%s' attribute",index);
@ -484,9 +502,14 @@ static int TvbRange_get_index(lua_State* L) {
return 0;
}
/*
* write access to tvbr's data
*/
static int TvbRange_set_index(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
const gchar* index = luaL_checkstring(L,2);
if (!tvbr) return 0;
if (g_str_equal(index,"offset")) {
int offset = lua_tonumber(L,3);
@ -496,7 +519,7 @@ static int TvbRange_set_index(lua_State* L) {
return 0;
} else {
tvbr->offset = offset;
pushTvbRange(L,tvbr);
PUSH_TVBRANGE(L,tvbr);
return 1;
}
} else if (g_str_equal(index,"len")) {
@ -507,7 +530,7 @@ static int TvbRange_set_index(lua_State* L) {
return 0;
} else {
tvbr->len = len;
pushTvbRange(L,tvbr);
PUSH_TVBRANGE(L,tvbr);
return 1;
}
} else {
@ -518,6 +541,9 @@ static int TvbRange_set_index(lua_State* L) {
return 0;
}
/*
* get a Blefuscuoan unsigned integer from a tvb
*/
static int TvbRange_get_uint(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
if (!tvbr) return 0;
@ -535,12 +561,22 @@ static int TvbRange_get_uint(lua_State* L) {
case 4:
lua_pushnumber(L,tvb_get_ntohl(tvbr->tvb,tvbr->offset));
return 1;
/*
* XXX:
* lua uses double so we have 52 bits to play with
* we are missing 5 and 6 byte integers within lua's range
* and 64 bit integers are not supported (there's a lib for
* lua that does).
*/
default:
luaL_error(L,"TvbRange:get_uint() does not handle %d byte integers",tvbr->len);
return 0;
}
}
/*
* get a Lilliputian unsigned integer from a tvb
*/
static int TvbRange_get_le_uint(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
if (!tvbr) return 0;
@ -565,13 +601,16 @@ static int TvbRange_get_le_uint(lua_State* L) {
}
}
/*
* get a Blefuscuoan float
*/
static int TvbRange_get_float(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
if (!tvbr) return 0;
switch (tvbr->len) {
case 4:
lua_pushnumber(L,tvb_get_ntohieee_float(tvbr->tvb,tvbr->offset));
lua_pushnumber(L,(double)tvb_get_ntohieee_float(tvbr->tvb,tvbr->offset));
return 1;
case 8:
lua_pushnumber(L,tvb_get_ntohieee_double(tvbr->tvb,tvbr->offset));
@ -582,6 +621,9 @@ static int TvbRange_get_float(lua_State* L) {
}
}
/*
* get a Lilliputian float
*/
static int TvbRange_get_le_float(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
if (!tvbr) return 0;
@ -661,6 +703,9 @@ static int TvbRange_get_bytes(lua_State* L) {
static int TvbRange_tostring(lua_State* L) {
TvbRange tvbr = checkTvbRange(L,1);
if (!tvbr) return 0;
lua_pushstring(L,tvb_bytes_to_str(tvbr->tvb,tvbr->offset,tvbr->len));
return 1;
}
@ -682,11 +727,13 @@ static const luaL_reg TvbRange_meta[] = {
{"__index", TvbRange_get_index},
{"__newindex", TvbRange_set_index},
{"__tostring", TvbRange_tostring},
{"__gc", TvbRange_gc},
{0, 0}
};
int TvbRange_register(lua_State* L) {
allocated_tvbrs = g_ptr_array_new();
luaL_openlib(L, TVB_RANGE, TvbRange_methods, 0);
luaL_newmetatable(L, TVB_RANGE);
luaL_openlib(L, 0, TvbRange_meta, 0);

2
plugins/lua/packet-lua.c
View File

@ -171,6 +171,8 @@ void dissect_lua(tvbuff_t* tvb, packet_info* pinfo, proto_tree* tree) {
expert_add_info_format(pinfo, pi, PI_DEBUG, PI_ERROR ,"Lua Error");
}
clear_outstanding_tvbs();
lua_pinfo = NULL;
lua_tree = NULL;
lua_tvb = NULL;

1
plugins/lua/packet-lua.h
View File

@ -255,5 +255,6 @@ extern void proto_register_lua(void);
extern GString* lua_register_all_taps(void);
extern void lua_prime_all_fields(proto_tree* tree);
extern void lua_register_subtrees(void);
extern void clear_outstanding_tvbs(void);
#endif