From: Christopher Faulet <cfaulet@haproxy.com>
Date: Mon, 16 Jun 2025 13:48:04 +0000 (+0200)
Subject: BUG/MEDIUM: cli: Don't consume data if outbuf is full or not available
X-Git-Tag: v3.3-dev2~53
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=396f0252bf3a400c9dbfdaf730e994bb44f198dd;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: cli: Don't consume data if outbuf is full or not available

The output buffer must be available to process a command, at least to be
able to emit error messages. When this buffer is full or cannot be
allocated, we must wait. In that case, we must take care to notify the SE
will not consume input data. It is important to avoid wakeup in loop,
especially when the client aborts.

When the output buffer is available again and no longer full, and the CLI
applet is waiting for a command line, it must notify it will consume input
data.

This patch must be backported as far as 3.0.
---

diff --git a/src/cli.c b/src/cli.c
index 49e8e3502..f76a91dcf 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -1086,10 +1086,9 @@ int cli_parse_cmdline(struct appctx *appctx)
  */
 void cli_io_handler(struct appctx *appctx)
 {
-	if (applet_fl_test(appctx, APPCTX_FL_OUTBLK_ALLOC|APPCTX_FL_OUTBLK_FULL))
-		goto out;
-
-	if (!appctx_get_buf(appctx, &appctx->outbuf)) {
+	if (applet_fl_test(appctx, APPCTX_FL_OUTBLK_ALLOC|APPCTX_FL_OUTBLK_FULL) ||
+	    !appctx_get_buf(appctx, &appctx->outbuf)) {
+                applet_wont_consume(appctx);
 		goto out;
 	}
 
@@ -1108,6 +1107,7 @@ void cli_io_handler(struct appctx *appctx)
 			break;
 		}
 		else if (appctx->st0 == CLI_ST_PARSE_CMDLINE) {
+			applet_will_consume(appctx);
 			if (cli_parse_cmdline(appctx) == 0) {
 				/* Now we close the output if we're not in interactive
 				 * mode and the request buffer is empty. This still