From: Stefan Eissing <stefan@eissing.org>
Date: Mon, 29 Dec 2025 10:21:31 +0000 (+0100)
Subject: ratelimit blocking: fix busy loop
X-Git-Tag: curl-8_18_0~75
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=52ac8104e1396998110e0760ac780f4f2414831f;p=thirdparty%2Fcurl.git

ratelimit blocking: fix busy loop

Fix the pollset in perform state to not add sockets for directions
that are blocked. This otherwise will lead to busy loops for a
transfer that cannot be progressed.

Reported-by: Fizn-Ahmd on github
Fixes #20091
Closes #20109
---

diff --git a/lib/multi.c b/lib/multi.c
index 92f6ca764d..aec0739c39 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -1080,10 +1080,9 @@ static CURLcode mstate_perform_pollset(struct Curl_easy *data,
     result = conn->handler->perform_pollset(data, ps);
   else {
     /* Default is to obey the data->req.keepon flags for send/recv */
-    if(CURL_WANT_RECV(data) && CONN_SOCK_IDX_VALID(conn->recv_idx)) {
+    if(Curl_req_want_recv(data) && CONN_SOCK_IDX_VALID(conn->recv_idx)) {
       result = Curl_pollset_add_in(data, ps, conn->sock[conn->recv_idx]);
     }
-
     if(!result && Curl_req_want_send(data) &&
        CONN_SOCK_IDX_VALID(conn->send_idx)) {
       result = Curl_pollset_add_out(data, ps, conn->sock[conn->send_idx]);
diff --git a/lib/request.c b/lib/request.c
index 90c10af99c..ad7f628f1a 100644
--- a/lib/request.c
+++ b/lib/request.c
@@ -415,16 +415,25 @@ bool Curl_req_sendbuf_empty(struct Curl_easy *data)
 
 bool Curl_req_want_send(struct Curl_easy *data)
 {
-  /* Not done and
-   * - KEEP_SEND and not PAUSEd.
-   * - or request has buffered data to send
-   * - or transfer connection has pending data to send */
+  /* Not done and upload not blocked and either one of
+   * - KEEP_SEND
+   * - request has buffered data to send
+   * - connection has pending data to send */
   return !data->req.done &&
+         !Curl_rlimit_is_blocked(&data->progress.ul.rlimit) &&
          ((data->req.keepon & KEEP_SEND) ||
           !Curl_req_sendbuf_empty(data) ||
           Curl_xfer_needs_flush(data));
 }
 
+bool Curl_req_want_recv(struct Curl_easy *data)
+{
+  /* Not done and download not blocked and KEEP_RECV */
+  return !data->req.done &&
+         !Curl_rlimit_is_blocked(&data->progress.dl.rlimit) &&
+         (data->req.keepon & KEEP_RECV);
+}
+
 bool Curl_req_done_sending(struct Curl_easy *data)
 {
   return data->req.upload_done && !Curl_req_want_send(data);
diff --git a/lib/request.h b/lib/request.h
index 0b006dc77c..389ae4d8b1 100644
--- a/lib/request.h
+++ b/lib/request.h
@@ -193,11 +193,13 @@ bool Curl_req_done_sending(struct Curl_easy *data);
  */
 CURLcode Curl_req_send_more(struct Curl_easy *data);
 
-/**
- * TRUE iff the request wants to send, e.g. has buffered bytes.
- */
+/* TRUE if the request wants to send, e.g. is not done sending
+ * and is not blocked. */
 bool Curl_req_want_send(struct Curl_easy *data);
 
+/* TRUE if the request wants to receive and is not blocked. */
+bool Curl_req_want_recv(struct Curl_easy *data);
+
 /**
  * TRUE iff the request has no buffered bytes yet to send.
  */