From: Christopher Faulet <cfaulet@haproxy.com>
Date: Tue, 12 Jan 2021 16:29:45 +0000 (+0100)
Subject: BUG/MINOR: check: Don't perform any check on servers defined in a frontend
X-Git-Tag: v2.4-dev6~66
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6ecd59326f7416dcba215f05a6674d4b9f970749;p=thirdparty%2Fhaproxy.git

BUG/MINOR: check: Don't perform any check on servers defined in a frontend

If a server is defined in a frontend, thus a proxy without the backend
capability, the 'check' and 'agent-check' keywords are ignored. This way, no
check is performed on an ignored server. This avoids a segfault because some
part of the tcpchecks are not fully initialized (or released for frontends
during the post-check).

In addition, an test on the server's proxy capabilities is performed when
checks or agent-checks are initialized and nothing is performed for servers
attached to a non-backend proxy.

This patch should fix the issue #1043. It must be backported as far as 2.2.
---

diff --git a/src/check.c b/src/check.c
index 51ae99ebfc..55470d5515 100644
--- a/src/check.c
+++ b/src/check.c
@@ -1272,7 +1272,7 @@ static int init_srv_check(struct server *srv)
 	int ret = ERR_NONE;
 	int check_type;
 
-	if (!srv->do_check)
+	if (!srv->do_check || !(srv->proxy->cap & PR_CAP_BE))
 		goto out;
 
 	check_type = srv->check.tcpcheck_rules->flags & TCPCHK_RULES_PROTO_CHK;
@@ -1397,7 +1397,7 @@ static int init_srv_agent_check(struct server *srv)
 	const char *err;
 	int ret = ERR_NONE;
 
-	if (!srv->do_agent)
+	if (!srv->do_agent || !(srv->proxy->cap & PR_CAP_BE))
 		goto out;
 
 	/* If there is no connect rule preceding all send / expect rules, an
@@ -1551,6 +1551,12 @@ static int srv_parse_agent_check(char **args, int *cur_arg, struct proxy *curpx,
 	if (srv->do_agent)
 		goto out;
 
+	if (!(curpx->cap & PR_CAP_BE)) {
+		memprintf(errmsg, "'%s' ignored because %s '%s' has no backend capability",
+			  args[*cur_arg], proxy_type_str(curpx), curpx->id);
+		return ERR_WARN;
+	}
+
 	if (!rules) {
 		rules = calloc(1, sizeof(*rules));
 		if (!rules) {
@@ -1750,6 +1756,12 @@ static int srv_parse_no_agent_check(char **args, int *cur_arg, struct proxy *cur
 static int srv_parse_check(char **args, int *cur_arg, struct proxy *curpx, struct server *srv,
 			   char **errmsg)
 {
+	if (!(curpx->cap & PR_CAP_BE)) {
+		memprintf(errmsg, "'%s' ignored because %s '%s' has no backend capability",
+			  args[*cur_arg], proxy_type_str(curpx), curpx->id);
+		return ERR_WARN;
+	}
+
 	srv->do_check = 1;
 	return 0;
 }