BUG/MEDIUM: check: tcp-check might miss some outgoing data when socket buffers are...

If a "tcp-check send" experiences an EAGAIN on a send() call, it will
nevertheless go to next rule, and will not try to send again if the next
rule is an expect.

Change this so that we always try to send whatever remains in the buffer
before doing anything else.

diff --git a/src/checks.c b/src/checks.c
index 1af672598af0a56b2258ccc2585685984b2d6911..6373783cf0cb7508eb232ac89da9e42d01047389 100644 (file)
--- a/src/checks.c
+++ b/src/checks.c
@@ -1981,7 +1981,23 @@ static void tcpcheck_main(struct connection *conn)
                cur = check->current_step;
        }
 
-       while (&cur->list != head) {
+       while (1) {
+               /* we must always ensure that nothing remains in the output buffer */
+               while (check->bo->o) {
+                       conn->xprt->snd_buf(conn, check->bo, MSG_DONTWAIT | MSG_NOSIGNAL);
+                       if (conn->flags & CO_FL_ERROR) {
+                               chk_report_conn_err(conn, errno, 0);
+                               __conn_data_stop_both(conn);
+                               goto out_end_tcpcheck;
+                       }
+                       if (conn->flags & CO_FL_WAIT_WR)
+                               goto out_incomplete;
+               }
+
+               /* did we reach the end ? */
+               if (&cur->list == head)
+                       break;
+
                if (check->current_step->action & TCPCHK_ACT_SEND) {
                        /* reset the read buffer */
                        if (*check->bi->data != '\0') {
@@ -1998,27 +2014,20 @@ static void tcpcheck_main(struct connection *conn)
                        if (conn->flags & (CO_FL_HANDSHAKE | CO_FL_WAIT_WR))
                                return;
 
-                       /* disable reading for now */
-                       __conn_data_stop_recv(conn);
+                       if (check->current_step->string_len >= check->bo->size) {
+                               chunk_printf(&trash, "tcp-check send : string too large (%d) for buffer size (%d) at step %d",
+                                            check->current_step->string_len, check->bo->size,
+                                            tcpcheck_get_step_id(s));
+                               set_server_check_status(check, HCHK_STATUS_L7RSP, trash.str);
+                               goto out_end_tcpcheck;
+                       }
 
                        bo_putblk(check->bo, check->current_step->string, check->current_step->string_len);
                        *check->bo->p = '\0'; /* to make gdb output easier to read */
 
-                       if (check->bo->o) {
-                               conn->xprt->snd_buf(conn, check->bo, MSG_DONTWAIT | MSG_NOSIGNAL);
-                               if (conn->flags & CO_FL_ERROR) {
-                                       chk_report_conn_err(conn, errno, 0);
-                                       __conn_data_stop_both(conn);
-                                       goto out_end_tcpcheck;
-                               }
-                       }
+                       /* go to next rule and try to send */
                        cur = (struct tcpcheck_rule *)cur->list.n;
                        check->current_step = cur;
-
-                       if (check->bo->o)
-                               goto out_incomplete;
-
-                       __conn_data_stop_send(conn);   /* nothing more to write */
                } /* end 'send' */
                else if (check->current_step->action & TCPCHK_ACT_EXPECT) {
                        if (unlikely(check->result & SRV_CHK_FAILED))