BUG/MEDIUM: hlua: Check the calling direction in lua functions of the HTTP class

It is invalid to manipulate responses from http-request rules or to manipulate
requests from http-response rules. When http-request rules are evaluated, the
connection to server is not yet established, so there is no response at all. And
when http-response rules are evaluated, the request has already been sent to the
server.

Now, the calling direction is checked. So functions "txn.http:req_*" can now
only be called from http-request rules and the functions "txn.http:res_*" can
only be called from http-response rules.

This issue was reported on Github (#190).

This patch must be backported to all versions since the 1.6.

src/hlua.c

@@ -4766,6 +4766,9 @@ __LJMP static int hlua_http_req_get_headers(lua_State *L)
 	MAY_LJMP(check_args(L, 1, "req_get_headers"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	return hlua_http_get_headers(L, htxn, &htxn->s->txn->req);
 }
 
@@ -4776,6 +4779,9 @@ __LJMP static int hlua_http_res_get_headers(lua_State *L)
 	MAY_LJMP(check_args(L, 1, "res_get_headers"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	return hlua_http_get_headers(L, htxn, &htxn->s->txn->rsp);
 }
 
@@ -4809,6 +4815,9 @@ __LJMP static int hlua_http_req_rep_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 4, "req_rep_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	return MAY_LJMP(hlua_http_rep_hdr(L, htxn, &htxn->s->txn->req, ACT_HTTP_REPLACE_HDR));
 }
 
@@ -4819,6 +4828,9 @@ __LJMP static int hlua_http_res_rep_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 4, "res_rep_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	return MAY_LJMP(hlua_http_rep_hdr(L, htxn, &htxn->s->txn->rsp, ACT_HTTP_REPLACE_HDR));
 }
 
@@ -4829,6 +4841,9 @@ __LJMP static int hlua_http_req_rep_val(lua_State *L)
 	MAY_LJMP(check_args(L, 4, "req_rep_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	return MAY_LJMP(hlua_http_rep_hdr(L, htxn, &htxn->s->txn->req, ACT_HTTP_REPLACE_VAL));
 }
 
@@ -4839,6 +4854,9 @@ __LJMP static int hlua_http_res_rep_val(lua_State *L)
 	MAY_LJMP(check_args(L, 4, "res_rep_val"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	return MAY_LJMP(hlua_http_rep_hdr(L, htxn, &htxn->s->txn->rsp, ACT_HTTP_REPLACE_VAL));
 }
 
@@ -4865,6 +4883,9 @@ __LJMP static int hlua_http_req_del_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 2, "req_del_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	return hlua_http_del_hdr(L, htxn, &htxn->s->txn->req);
 }
 
@@ -4872,9 +4893,12 @@ __LJMP static int hlua_http_res_del_hdr(lua_State *L)
 {
 	struct hlua_txn *htxn;
 
-	MAY_LJMP(check_args(L, 2, "req_del_hdr"));
+	MAY_LJMP(check_args(L, 2, "res_del_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	return hlua_http_del_hdr(L, htxn, &htxn->s->txn->rsp);
 }
 
@@ -4901,6 +4925,9 @@ __LJMP static int hlua_http_req_add_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 3, "req_add_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	return hlua_http_add_hdr(L, htxn, &htxn->s->txn->req);
 }
 
@@ -4911,6 +4938,9 @@ __LJMP static int hlua_http_res_add_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 3, "res_add_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	return hlua_http_add_hdr(L, htxn, &htxn->s->txn->rsp);
 }
 
@@ -4921,6 +4951,9 @@ static int hlua_http_req_set_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 3, "req_set_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	hlua_http_del_hdr(L, htxn, &htxn->s->txn->req);
 	return hlua_http_add_hdr(L, htxn, &htxn->s->txn->req);
 }
@@ -4932,6 +4965,9 @@ static int hlua_http_res_set_hdr(lua_State *L)
 	MAY_LJMP(check_args(L, 3, "res_set_hdr"));
 	htxn = MAY_LJMP(hlua_checkhttp(L, 1));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	hlua_http_del_hdr(L, htxn, &htxn->s->txn->rsp);
 	return hlua_http_add_hdr(L, htxn, &htxn->s->txn->rsp);
 }
@@ -4943,6 +4979,9 @@ static int hlua_http_req_set_meth(lua_State *L)
 	size_t name_len;
 	const char *name = MAY_LJMP(luaL_checklstring(L, 2, &name_len));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	lua_pushboolean(L, http_req_replace_stline(0, name, name_len, htxn->p, htxn->s) != -1);
 	return 1;
 }
@@ -4954,6 +4993,9 @@ static int hlua_http_req_set_path(lua_State *L)
 	size_t name_len;
 	const char *name = MAY_LJMP(luaL_checklstring(L, 2, &name_len));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	lua_pushboolean(L, http_req_replace_stline(1, name, name_len, htxn->p, htxn->s) != -1);
 	return 1;
 }
@@ -4965,6 +5007,9 @@ static int hlua_http_req_set_query(lua_State *L)
 	size_t name_len;
 	const char *name = MAY_LJMP(luaL_checklstring(L, 2, &name_len));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	/* Check length. */
 	if (name_len > trash.size - 1) {
 		lua_pushboolean(L, 0);
@@ -4989,6 +5034,9 @@ static int hlua_http_req_set_uri(lua_State *L)
 	size_t name_len;
 	const char *name = MAY_LJMP(luaL_checklstring(L, 2, &name_len));
 
+	if (htxn->dir != SMP_OPT_DIR_REQ)
+		WILL_LJMP(lua_error(L));
+
 	lua_pushboolean(L, http_req_replace_stline(3, name, name_len, htxn->p, htxn->s) != -1);
 	return 1;
 }
@@ -5000,6 +5048,9 @@ static int hlua_http_res_set_status(lua_State *L)
 	unsigned int code = MAY_LJMP(luaL_checkinteger(L, 2));
 	const char *reason = MAY_LJMP(luaL_optlstring(L, 3, NULL, NULL));
 
+	if (htxn->dir != SMP_OPT_DIR_RES)
+		WILL_LJMP(lua_error(L));
+
 	http_res_set_status(code, reason, htxn->s);
 	return 0;
 }