From: Aurelien Degremont <adegremont@nvidia.com>
Date: Mon, 5 May 2025 14:36:16 +0000 (+0200)
Subject: LU-18976 gss: detect dns error in lsvcgssd
X-Git-Tag: 2.16.56~41
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=refs%2Fchanges%2F95%2F59095%2F2;p=fs%2Flustre-release.git

LU-18976 gss: detect dns error in lsvcgssd

Use proper NI_NAMEREQD flag with getnameinfo() in lsvcgssd when
resolving IP addresses, for it to return an error if DNS resolution fails.

That way, the error is propagated and Lustre knows a DNS failure happens
and can report it better. If not, it fails latter and reports a very unclear
message.

Test-Parameters: kerberos=true testlist=sanity-krb5
Change-Id: Iaa9e718c056ea742d8695048e43bdeeb3205f0dd
Signed-off-by: Aurelien Degremont <adegremont@nvidia.com>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/59095
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Bruno Faccini <bfaccini@nvidia.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
---

diff --git a/lustre/utils/gss/lsupport.c b/lustre/utils/gss/lsupport.c
index 4126fee..39a4d89 100644
--- a/lustre/utils/gss/lsupport.c
+++ b/lustre/utils/gss/lsupport.c
@@ -228,6 +228,7 @@ out:
 static int getaddrcanonname(const uint32_t addr, char *buf, int buflen)
 {
 	struct sockaddr_in srcaddr;
+	char ipstr[INET_ADDRSTRLEN] = "\0";
 	int err = 0;
 	int rc = -1;
 
@@ -248,13 +249,18 @@ static int getaddrcanonname(const uint32_t addr, char *buf, int buflen)
 	srcaddr.sin_addr.s_addr = (in_addr_t)addr;
 
 	err = getnameinfo((struct sockaddr *)&srcaddr, sizeof(srcaddr),
-			  buf, buflen, NULL, 0, 0);
+			  buf, buflen, NULL, 0, NI_NAMEREQD);
 	if (err != 0) {
-		printerr(LL_ERR,
-			 "failed to get nameinfo for 0x%x: %s\n",
-			 addr, gai_strerror(err));
+		if (inet_ntop(srcaddr.sin_family, &srcaddr.sin_addr, ipstr,
+			      INET_ADDRSTRLEN))
+			printerr(LL_ERR, "failed to get name for %s: %s\n",
+				 ipstr, gai_strerror(err));
+		else
+			printerr(LL_ERR, "failed to get name for 0x%x: %s\n",
+				 addr, gai_strerror(err));
 		goto out;
 	}
+
 	rc = 0;
 
 out: