commit dc2ee27c7a1908ca3157a10ad131f13644bcaea3
Author: Christopher Faulet <cfaulet@haproxy.com>
Date:   Fri Jul 26 16:17:01 2019 +0200

    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.
    
    (cherry picked from commit 84a6d5bc217a418db8efc4e76a0a32860db2c608)
    Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/hlua.c b/src/hlua.c
index f9d1d699..21351cd6 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -5346,6 +5346,9 @@ __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);
 }
 
@@ -5356,6 +5359,9 @@ __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);
 }
 
@@ -5393,6 +5399,9 @@ __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));
 }
 
@@ -5403,6 +5412,9 @@ __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));
 }
 
@@ -5413,6 +5425,9 @@ __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));
 }
 
@@ -5423,6 +5438,9 @@ __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));
 }
 
@@ -5462,6 +5480,9 @@ __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);
 }
 
@@ -5469,9 +5490,12 @@ __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);
 }
 
@@ -5523,6 +5547,9 @@ __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);
 }
 
@@ -5533,6 +5560,9 @@ __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);
 }
 
@@ -5543,6 +5573,9 @@ 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);
 }
@@ -5554,6 +5587,9 @@ 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);
 }
@@ -5565,6 +5601,9 @@ 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_replace_req_line(0, name, name_len, htxn->p, htxn->s) != -1);
 	return 1;
 }
@@ -5576,6 +5615,9 @@ 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_replace_req_line(1, name, name_len, htxn->p, htxn->s) != -1);
 	return 1;
 }
@@ -5587,6 +5629,9 @@ 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);
@@ -5611,6 +5656,9 @@ 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_replace_req_line(3, name, name_len, htxn->p, htxn->s) != -1);
 	return 1;
 }
@@ -5622,6 +5670,9 @@ 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_set_status(code, reason, htxn->s);
 	return 0;
 }