BUG/MEDIUM: hlua: Fix end of request detection when retrieving payload

When the lua HTTP applet was refactored to use its own buffers, a bug was
introduced in receive() and getline() function. We rely on HTX_FL_EOM flag
to detect the end of the request. But there is nothing preventing extra
calls to these function, when the whole request was consumed. If this
happens, the call will yield waiting for more data with no way to stop it.

To fix the issue, APPLET_REQ_RECV flag was added to know the whole request
was received.

This patch should fix #3293. It must be backported to 3.3.

diff --git a/src/hlua.c b/src/hlua.c
index a31ada50fa2c71385002f1732e542e579c714aae..950751b46f0f2daa5e210f2df2b7c2fd01d247e3 100644 (file)
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -381,6 +381,7 @@ static const char *hlua_pushfstring_safe(lua_State *L, const char *fmt, ...)
 
 /* Applet status flags */
 #define APPLET_DONE     0x01 /* applet processing is done. */
+#define APPLET_REQ_RECV 0x02 /* The request was fully received */
 /* unused: 0x02 */
 #define APPLET_HDR_SENT 0x04 /* Response header sent. */
 /* unused: 0x08, 0x10 */
@@ -5770,11 +5771,15 @@ __LJMP static int hlua_applet_http_get_priv(lua_State *L)
 __LJMP static int hlua_applet_http_getline_yield(lua_State *L, int status, lua_KContext ctx)
 {
        struct hlua_appctx *luactx = MAY_LJMP(hlua_checkapplet_http(L, 1));
+       struct hlua_http_ctx *http_ctx = luactx->appctx->svcctx;
        struct buffer *inbuf = applet_get_inbuf(luactx->appctx);
        struct htx *htx;
        struct htx_blk *blk;
        int stop = 0;
 
+       if (http_ctx->flags & APPLET_REQ_RECV)
+               goto end;
+
        if (!inbuf)
                goto wait;
 
@@ -5823,8 +5828,10 @@ __LJMP static int hlua_applet_http_getline_yield(lua_State *L, int status, lua_K
        /* The message was fully consumed and no more data are expected
         * (EOM flag set).
         */
-       if (htx_is_empty(htx) && (htx->flags & HTX_FL_EOM))
+       if (htx_is_empty(htx) && (htx->flags & HTX_FL_EOM)) {
+               http_ctx->flags |= APPLET_REQ_RECV;
                stop = 1;
+       }
 
        htx_to_buf(htx, inbuf);
        if (!stop) {
@@ -5833,6 +5840,7 @@ __LJMP static int hlua_applet_http_getline_yield(lua_State *L, int status, lua_K
                MAY_LJMP(hlua_yieldk(L, 0, 0, hlua_applet_http_getline_yield, TICK_ETERNITY, 0));
        }
 
+  end:
        /* Stop to consume until the next receive or the end of the response */
        applet_wont_consume(luactx->appctx);
 
@@ -5863,11 +5871,15 @@ __LJMP static int hlua_applet_http_getline(lua_State *L)
 __LJMP static int hlua_applet_http_recv_yield(lua_State *L, int status, lua_KContext ctx)
 {
        struct hlua_appctx *luactx = MAY_LJMP(hlua_checkapplet_http(L, 1));
+       struct hlua_http_ctx *http_ctx = luactx->appctx->svcctx;
        struct buffer *inbuf = applet_get_inbuf(luactx->appctx);
        struct htx *htx;
        struct htx_blk *blk;
        int len;
 
+       if (http_ctx->flags & APPLET_REQ_RECV)
+               goto end;
+
        if (!inbuf)
                goto wait;
 
@@ -5915,8 +5927,10 @@ __LJMP static int hlua_applet_http_recv_yield(lua_State *L, int status, lua_KCon
        /* The message was fully consumed and no more data are expected
         * (EOM flag set).
         */
-       if (htx_is_empty(htx) && (htx->flags & HTX_FL_EOM))
+       if (htx_is_empty(htx) && (htx->flags & HTX_FL_EOM)) {
+               http_ctx->flags |= APPLET_REQ_RECV;
                len = 0;
+       }
 
        htx_to_buf(htx, inbuf);
        applet_fl_clr(luactx->appctx, APPCTX_FL_INBLK_FULL);
@@ -5932,6 +5946,7 @@ __LJMP static int hlua_applet_http_recv_yield(lua_State *L, int status, lua_KCon
                MAY_LJMP(hlua_yieldk(L, 0, 0, hlua_applet_http_recv_yield, TICK_ETERNITY, 0));
        }
 
+  end:
        /* Stop to consume until the next receive or the end of the response */
        applet_wont_consume(luactx->appctx);