MFC r292539:

  If we end up following a CNAME chain that does not find
  any data return that instead of internal error.

PR:		156684

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/libc/net/getaddrinfo.c b/lib/libc/net/getaddrinfo.c
index 4d1972d..4733e51 100644
--- a/lib/libc/net/getaddrinfo.c
+++ b/lib/libc/net/getaddrinfo.c
@@ -2166,7 +2166,11 @@ getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
 		return sentinel.ai_next;
 	}
 
-	RES_SET_H_ERRNO(res, NO_RECOVERY);
+	/*
+	 * We could have walked a CNAME chain, but the ultimate target
+	 * may not have what we looked for.
+	 */
+	RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : NO_RECOVERY);
 	return NULL;
 }
 
@@ -2343,6 +2347,7 @@ _dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
 	if (sentinel.ai_next == NULL)
 		switch (res->res_h_errno) {
 		case HOST_NOT_FOUND:
+		case NO_DATA:
 			return NS_NOTFOUND;
 		case TRY_AGAIN:
 			return NS_TRYAGAIN;