mirror of
https://github.com/haproxy/haproxy.git
synced 2026-02-20 00:10:41 -05:00
BUG/MINOR: hlua: don't use lua_tostring() from unprotected contexts
As per lua documentation, lua_tostring() may raise a memory error. However, we're often using it to fetch the error message at the top of the stack (ie: after a failing lua call) from unprotected environments. In practise, lua_tostring() has rare chances of failing, but still, if it happens to be the case, it could crash the process and we better not risk it. So here, we add hlua_tostring_safe() function, which works exactly as lua_tostring(), but the function cannot LJMP as it will catch lua_tostring() exceptions to return NULL instead. Everywhere lua_tostring() was used to retrieve error string from such unprotected contexts, we now rely on hlua_tostring_safe(). This should be backported to all stable versions. [ada: ctx adj will be required, for versions prior to 2.8 event_hdl API didn't exist so some chunks won't apply, and prior to 2.5 filters API didn't exist either, so again, some chunks should be ignored]
This commit is contained in:
Aurelien DARRAGON
parent
5508db9a20
commit
369bfa0b50
1 changed files with 86 additions and 34 deletions
120
src/hlua.c
120
src/hlua.c
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@ -208,6 +208,58 @@ static inline void hlua_unlock(struct hlua *hlua)
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lua_drop_global_lock();
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}
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/* below is an helper function to retrieve string on on Lua stack at <index>
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* in a safe way (function may not LJMP). It can be useful to retrieve errors
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* at the top of the stack from an unprotected environment.
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*
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* The returned string will is only valid as long as the value at <index> is
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* not removed from the stack.
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*
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* It is assumed that the calling function is allowed to manipulate <L>
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*/
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__LJMP static int _hlua_tostring_safe(lua_State *L)
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{
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const char **str = lua_touserdata(L, 1);
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const char *cur_str = MAY_LJMP(lua_tostring(L, 2));
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if (cur_str)
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*str = cur_str;
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return 0;
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}
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static const char *hlua_tostring_safe(lua_State *L, int index)
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{
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const char *str = NULL;
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if (!lua_checkstack(L, 4))
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return NULL;
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/* before any stack modification, save the targeted value on the top of
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* the stack: this will allow us to use relative index to target it.
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*/
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lua_pushvalue(L, index);
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/* push our custom _hlua_tostring_safe() function on the stack, then push
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* our own string pointer and targeted value (at <index>) as argument
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*/
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lua_pushcfunction(L, _hlua_tostring_safe);
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lua_pushlightuserdata(L, &str); // 1st func argument = string pointer
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lua_pushvalue(L, -3); // 2nd func argument = targeted value
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lua_remove(L, -4); // remove <index> copy as we're done using it
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/* call our custom function with proper arguments using pcall() to catch
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* exceptions (if any)
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*/
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switch (lua_pcall(L, 2, 0, 0)) {
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case LUA_OK:
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break;
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default:
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/* error was caught */
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return NULL;
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}
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return str;
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}
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#define SET_SAFE_LJMP_L(__L, __HLUA) \
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({ \
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int ret; \
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@ -1820,7 +1872,7 @@ resume_execution:
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ret = HLUA_E_ERR;
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break;
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}
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msg = lua_tostring(lua->T, -1);
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msg = hlua_tostring_safe(lua->T, -1);
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trace = hlua_traceback(lua->T, ", ");
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if (msg)
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lua_pushfstring(lua->T, "[state-id %d] runtime error: %s from %s", lua->state_id, msg, trace);
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@ -1845,7 +1897,7 @@ resume_execution:
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ret = HLUA_E_ERR;
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break;
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}
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msg = lua_tostring(lua->T, -1);
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msg = hlua_tostring_safe(lua->T, -1);
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if (msg)
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lua_pushfstring(lua->T, "[state-id %d] message handler error: %s", lua->state_id, msg);
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else
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@ -8984,7 +9036,7 @@ struct task *hlua_process_task(struct task *task, void *context, unsigned int st
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SEND_ERR(NULL, "Lua task: execution timeout.\n");
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goto err_task_abort;
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case HLUA_E_ERRMSG:
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SEND_ERR(NULL, "Lua task: %s.\n", lua_tostring(hlua->T, -1));
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SEND_ERR(NULL, "Lua task: %s.\n", hlua_tostring_safe(hlua->T, -1));
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goto err_task_abort;
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case HLUA_E_ERR:
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default:
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@ -9259,7 +9311,7 @@ static void hlua_event_handler(struct hlua *hlua)
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break;
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case HLUA_E_ERRMSG:
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SEND_ERR(NULL, "Lua event_hdl: %s.\n", lua_tostring(hlua->T, -1));
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SEND_ERR(NULL, "Lua event_hdl: %s.\n", hlua_tostring_safe(hlua->T, -1));
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break;
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case HLUA_E_ERR:
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@ -9598,7 +9650,7 @@ static struct task *hlua_event_runner(struct task *task, void *context, unsigned
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(hlua_sub->hlua)) {
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if (lua_type(hlua_sub->hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(hlua_sub->hlua->T, -1);
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error = hlua_tostring_safe(hlua_sub->hlua->T, -1);
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else
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error = "critical error";
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ha_alert("Lua event_hdl: %s.\n", error);
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@ -9893,7 +9945,7 @@ static int hlua_sample_conv_wrapper(const struct arg *arg_p, struct sample *smp,
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(stream->hlua)) {
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if (lua_type(stream->hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(stream->hlua->T, -1);
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error = hlua_tostring_safe(stream->hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(stream->be, "Lua converter '%s': %s.\n", fcn->name, error);
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@ -9965,7 +10017,7 @@ static int hlua_sample_conv_wrapper(const struct arg *arg_p, struct sample *smp,
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case HLUA_E_ERRMSG:
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/* Display log. */
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SEND_ERR(stream->be, "Lua converter '%s': %s.\n",
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fcn->name, lua_tostring(stream->hlua->T, -1));
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fcn->name, hlua_tostring_safe(stream->hlua->T, -1));
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lua_pop(stream->hlua->T, 1);
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return 0;
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@ -10018,7 +10070,7 @@ static int hlua_sample_fetch_wrapper(const struct arg *arg_p, struct sample *smp
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(stream->hlua)) {
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if (lua_type(stream->hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(stream->hlua->T, -1);
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error = hlua_tostring_safe(stream->hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(smp->px, "Lua sample-fetch '%s': %s.\n", fcn->name, error);
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@ -10091,7 +10143,7 @@ static int hlua_sample_fetch_wrapper(const struct arg *arg_p, struct sample *smp
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case HLUA_E_ERRMSG:
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/* Display log. */
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SEND_ERR(smp->px, "Lua sample-fetch '%s': %s.\n",
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fcn->name, lua_tostring(stream->hlua->T, -1));
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fcn->name, hlua_tostring_safe(stream->hlua->T, -1));
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lua_pop(stream->hlua->T, 1);
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return 0;
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@ -10348,7 +10400,7 @@ static enum act_return hlua_action(struct act_rule *rule, struct proxy *px,
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(s->hlua)) {
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if (lua_type(s->hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(s->hlua->T, -1);
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error = hlua_tostring_safe(s->hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(px, "Lua function '%s': %s.\n",
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@ -10442,7 +10494,7 @@ static enum act_return hlua_action(struct act_rule *rule, struct proxy *px,
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case HLUA_E_ERRMSG:
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/* Display log. */
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SEND_ERR(px, "Lua function '%s': %s.\n",
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rule->arg.hlua_rule->fcn->name, lua_tostring(s->hlua->T, -1));
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rule->arg.hlua_rule->fcn->name, hlua_tostring_safe(s->hlua->T, -1));
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lua_pop(s->hlua->T, 1);
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goto end;
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@ -10534,7 +10586,7 @@ static int hlua_applet_tcp_init(struct appctx *ctx)
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(hlua)) {
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if (lua_type(hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(hlua->T, -1);
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error = hlua_tostring_safe(hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(strm->be, "Lua applet tcp '%s': %s.\n",
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@ -10617,7 +10669,7 @@ void hlua_applet_tcp_fct(struct appctx *ctx)
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case HLUA_E_ERRMSG:
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/* Display log. */
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SEND_ERR(px, "Lua applet tcp '%s': %s.\n",
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rule->arg.hlua_rule->fcn->name, lua_tostring(hlua->T, -1));
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rule->arg.hlua_rule->fcn->name, hlua_tostring_safe(hlua->T, -1));
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lua_pop(hlua->T, 1);
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goto error;
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@ -10725,7 +10777,7 @@ static int hlua_applet_http_init(struct appctx *ctx)
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(hlua)) {
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if (lua_type(hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(hlua->T, -1);
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error = hlua_tostring_safe(hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(strm->be, "Lua applet http '%s': %s.\n",
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@ -10826,7 +10878,7 @@ void hlua_applet_http_fct(struct appctx *ctx)
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case HLUA_E_ERRMSG:
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/* Display log. */
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SEND_ERR(px, "Lua applet http '%s': %s.\n",
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rule->arg.hlua_rule->fcn->name, lua_tostring(hlua->T, -1));
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rule->arg.hlua_rule->fcn->name, hlua_tostring_safe(hlua->T, -1));
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lua_pop(hlua->T, 1);
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goto error;
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@ -11365,7 +11417,7 @@ static int hlua_cli_parse_fct(char **args, char *payload, struct appctx *appctx,
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/* The following Lua calls can fail. */
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if (!SET_SAFE_LJMP(hlua)) {
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if (lua_type(hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(hlua->T, -1);
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error = hlua_tostring_safe(hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(NULL, "Lua cli '%s': %s.\n", fcn->name, error);
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@ -11450,7 +11502,7 @@ static int hlua_cli_io_handler_fct(struct appctx *appctx)
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case HLUA_E_ERRMSG:
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/* Display log. */
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SEND_ERR(NULL, "Lua cli '%s': %s.\n",
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fcn->name, lua_tostring(hlua->T, -1));
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fcn->name, hlua_tostring_safe(hlua->T, -1));
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lua_pop(hlua->T, 1);
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return 1;
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@ -11704,21 +11756,21 @@ static int hlua_filter_init_per_thread(struct proxy *px, struct flt_conf *fconf)
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conf->ref[state_id] = flt_ref;
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break;
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case LUA_ERRRUN:
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ha_alert("Lua filter '%s' : runtime error : %s", conf->reg->name, lua_tostring(L, -1));
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ha_alert("Lua filter '%s' : runtime error : %s", conf->reg->name, hlua_tostring_safe(L, -1));
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goto error;
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case LUA_ERRMEM:
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ha_alert("Lua filter '%s' : out of memory error", conf->reg->name);
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goto error;
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case LUA_ERRERR:
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ha_alert("Lua filter '%s' : message handler error : %s", conf->reg->name, lua_tostring(L, -1));
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ha_alert("Lua filter '%s' : message handler error : %s", conf->reg->name, hlua_tostring_safe(L, -1));
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goto error;
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#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM <= 503
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case LUA_ERRGCMM:
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ha_alert("Lua filter '%s' : garbage collector error : %s", conf->reg->name, lua_tostring(L, -1));
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ha_alert("Lua filter '%s' : garbage collector error : %s", conf->reg->name, hlua_tostring_safe(L, -1));
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goto error;
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#endif
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default:
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ha_alert("Lua filter '%s' : unknown error : %s", conf->reg->name, lua_tostring(L, -1));
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ha_alert("Lua filter '%s' : unknown error : %s", conf->reg->name, hlua_tostring_safe(L, -1));
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goto error;
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}
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@ -11820,7 +11872,7 @@ static int hlua_filter_new(struct stream *s, struct filter *filter)
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const char *error;
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if (lua_type(s->hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(s->hlua->T, -1);
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error = hlua_tostring_safe(s->hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(s->be, "Lua filter '%s': %s.\n", conf->reg->name, error);
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@ -11875,7 +11927,7 @@ static int hlua_filter_new(struct stream *s, struct filter *filter)
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filter->ctx = flt_ctx;
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break;
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case HLUA_E_ERRMSG:
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SEND_ERR(s->be, "Lua filter '%s' : %s.\n", conf->reg->name, lua_tostring(s->hlua->T, -1));
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SEND_ERR(s->be, "Lua filter '%s' : %s.\n", conf->reg->name, hlua_tostring_safe(s->hlua->T, -1));
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ret = -1;
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goto end;
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case HLUA_E_ETMOUT:
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@ -11953,7 +12005,7 @@ static int hlua_filter_callback(struct stream *s, struct filter *filter, const c
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const char *error;
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if (lua_type(flt_hlua->T, -1) == LUA_TSTRING)
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error = lua_tostring(flt_hlua->T, -1);
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error = hlua_tostring_safe(flt_hlua->T, -1);
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else
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error = "critical error";
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SEND_ERR(s->be, "Lua filter '%s': %s.\n", conf->reg->name, error);
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@ -12061,7 +12113,7 @@ static int hlua_filter_callback(struct stream *s, struct filter *filter, const c
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ret = 0;
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goto end;
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case HLUA_E_ERRMSG:
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SEND_ERR(s->be, "Lua filter '%s' : %s.\n", conf->reg->name, lua_tostring(flt_hlua->T, -1));
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SEND_ERR(s->be, "Lua filter '%s' : %s.\n", conf->reg->name, hlua_tostring_safe(flt_hlua->T, -1));
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ret = -1;
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goto end;
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case HLUA_E_ETMOUT:
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@ -12550,7 +12602,7 @@ static int hlua_load_state(char **args, lua_State *L, char **err)
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/* Just load and compile the file. */
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error = luaL_loadfile(L, args[0]);
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if (error) {
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memprintf(err, "error in Lua file '%s': %s", args[0], lua_tostring(L, -1));
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memprintf(err, "error in Lua file '%s': %s", args[0], hlua_tostring_safe(L, -1));
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lua_pop(L, 1);
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return -1;
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}
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@ -12572,24 +12624,24 @@ static int hlua_load_state(char **args, lua_State *L, char **err)
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case LUA_OK:
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break;
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case LUA_ERRRUN:
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memprintf(err, "Lua runtime error: %s", lua_tostring(L, -1));
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memprintf(err, "Lua runtime error: %s", hlua_tostring_safe(L, -1));
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lua_pop(L, 1);
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return -1;
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case LUA_ERRMEM:
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memprintf(err, "Lua out of memory error");
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return -1;
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case LUA_ERRERR:
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memprintf(err, "Lua message handler error: %s", lua_tostring(L, -1));
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memprintf(err, "Lua message handler error: %s", hlua_tostring_safe(L, -1));
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lua_pop(L, 1);
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return -1;
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#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM <= 503
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case LUA_ERRGCMM:
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memprintf(err, "Lua garbage collector error: %s", lua_tostring(L, -1));
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memprintf(err, "Lua garbage collector error: %s", hlua_tostring_safe(L, -1));
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lua_pop(L, 1);
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return -1;
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#endif
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default:
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memprintf(err, "Lua unknown error: %s", lua_tostring(L, -1));
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memprintf(err, "Lua unknown error: %s", hlua_tostring_safe(L, -1));
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lua_pop(L, 1);
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return -1;
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}
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@ -12741,7 +12793,7 @@ static int hlua_config_prepend_path(char **args, int section_type, struct proxy
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if (setjmp(safe_ljmp_env) != 0) {
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lua_atpanic(L, hlua_panic_safe);
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if (lua_type(L, -1) == LUA_TSTRING)
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error = lua_tostring(L, -1);
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error = hlua_tostring_safe(L, -1);
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else
|
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error = "critical error";
|
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fprintf(stderr, "lua-prepend-path: %s.\n", error);
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@ -13010,7 +13062,7 @@ int hlua_post_init_state(lua_State *L)
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if (setjmp(safe_ljmp_env) != 0) {
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lua_atpanic(L, hlua_panic_safe);
|
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if (lua_type(L, -1) == LUA_TSTRING)
|
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error = lua_tostring(L, -1);
|
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error = hlua_tostring_safe(L, -1);
|
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else
|
||||
error = "critical error";
|
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fprintf(stderr, "Lua post-init: %s.\n", error);
|
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|
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@ -13044,7 +13096,7 @@ int hlua_post_init_state(lua_State *L)
|
|||
case LUA_ERRRUN:
|
||||
if (!kind)
|
||||
kind = "runtime error";
|
||||
msg = lua_tostring(L, -1);
|
||||
msg = hlua_tostring_safe(L, -1);
|
||||
trace = hlua_traceback(L, ", ");
|
||||
if (msg)
|
||||
ha_alert("Lua init: %s: '%s' from %s\n", kind, msg, trace);
|
||||
|
|
@ -13305,7 +13357,7 @@ lua_State *hlua_init_state(int thread_num)
|
|||
if (setjmp(safe_ljmp_env) != 0) {
|
||||
lua_atpanic(L, hlua_panic_safe);
|
||||
if (lua_type(L, -1) == LUA_TSTRING)
|
||||
error_msg = lua_tostring(L, -1);
|
||||
error_msg = hlua_tostring_safe(L, -1);
|
||||
else
|
||||
error_msg = "critical error";
|
||||
fprintf(stderr, "Lua init: %s.\n", error_msg);
|
||||
|
|
|
|||
Loading…
Reference in a new issue