BUG/MEDIUM: lua: the function txn_done() from sample fetches can crash
The function txn_done() ends a transaction. It does not make
sense to call this function from a lua sample-fetch wrapper,
because the role of a sample-fetch is not to terminate a
transaction.
This patch modify the role of the fucntion txn_done() if it
is called from a sample-fetch wrapper, now it just ends the
execution of the Lua code like the done() function.
Must be backported in 1.6
diff --git a/doc/lua-api/index.rst b/doc/lua-api/index.rst
index 2bca4d0..dccf415 100644
--- a/doc/lua-api/index.rst
+++ b/doc/lua-api/index.rst
@@ -1460,6 +1460,11 @@
session. It can be used when a critical error is detected or to terminate
processing after some data have been returned to the client (eg: a redirect).
+ *Warning*: It not make sense to call this function from sample-fetches. In
+ this case the behaviour of this one is the same than core.done(): it quit
+ the Lua execution. The transaction is really aborted only from an action
+ registered function.
+
:param class_txn txn: The class txn object containing the data.
.. js:function:: TXN.set_loglevel(txn, loglevel)
diff --git a/include/types/hlua.h b/include/types/hlua.h
index 43e9f1a..b22e03e 100644
--- a/include/types/hlua.h
+++ b/include/types/hlua.h
@@ -35,6 +35,8 @@
#define HLUA_F_AS_STRING 0x01
#define HLUA_F_MAY_USE_HTTP 0x02
+#define HLUA_TXN_NOTERM 0x00000001
+
#define HLUA_CONCAT_BLOCSZ 2048
enum hlua_exec {
@@ -109,6 +111,7 @@
struct stream *s;
struct proxy *p;
int dir; /* SMP_OPT_DIR_{REQ,RES} */
+ int flags;
};
/* This struct contains the applet context. */
diff --git a/src/hlua.c b/src/hlua.c
index 953c219..f9a317d 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -4601,7 +4601,7 @@
* return 0 if the stack does not contains free slots,
* otherwise it returns 1.
*/
-static int hlua_txn_new(lua_State *L, struct stream *s, struct proxy *p, int dir)
+static int hlua_txn_new(lua_State *L, struct stream *s, struct proxy *p, int dir, int flags)
{
struct hlua_txn *htxn;
@@ -4621,6 +4621,7 @@
htxn->s = s;
htxn->p = p;
htxn->dir = dir;
+ htxn->flags = flags;
/* Create the "f" field that contains a list of fetches. */
lua_pushstring(L, "f");
@@ -4814,6 +4815,15 @@
MAY_LJMP(check_args(L, 1, "close"));
htxn = MAY_LJMP(hlua_checktxn(L, 1));
+ /* If the flags NOTERM is set, we cannot terminate the http
+ * session, so we just end the execution of the current
+ * lua code.
+ */
+ if (htxn->flags & HLUA_TXN_NOTERM) {
+ WILL_LJMP(hlua_done(L));
+ return 0;
+ }
+
ic = &htxn->s->req;
oc = &htxn->s->res;
@@ -5265,7 +5275,8 @@
lua_rawgeti(stream->hlua.T, LUA_REGISTRYINDEX, fcn->function_ref);
/* push arguments in the stack. */
- if (!hlua_txn_new(stream->hlua.T, stream, smp->px, smp->opt & SMP_OPT_DIR)) {
+ if (!hlua_txn_new(stream->hlua.T, stream, smp->px, smp->opt & SMP_OPT_DIR,
+ HLUA_TXN_NOTERM)) {
SEND_ERR(smp->px, "Lua sample-fetch '%s': full stack.\n", fcn->name);
RESET_SAFE_LJMP(stream->hlua.T);
return 0;
@@ -5511,7 +5522,7 @@
lua_rawgeti(s->hlua.T, LUA_REGISTRYINDEX, rule->arg.hlua_rule->fcn.function_ref);
/* Create and and push object stream in the stack. */
- if (!hlua_txn_new(s->hlua.T, s, px, dir)) {
+ if (!hlua_txn_new(s->hlua.T, s, px, dir, 0)) {
SEND_ERR(px, "Lua function '%s': full stack.\n",
rule->arg.hlua_rule->fcn.name);
RESET_SAFE_LJMP(s->hlua.T);