From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 16 Oct 2018 17:32:26 +0000 (+0900)
Subject: resolve: set IP_RECVERR
X-Git-Tag: v240~526
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9fcdab9c8747ab092ac120b58de2ee7b1be9d7db;p=thirdparty%2Fsystemd.git

resolve: set IP_RECVERR

Closes #10345.
---

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 57af95c41f8..0c96332c75d 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -411,6 +411,13 @@ static int dns_scope_socket(
                 }
         }
 
+        if (type == SOCK_DGRAM) {
+                /* Set IP_RECVERR or IPV6_RECVERR to get ICMP error feedback. See discussion in #10345. */
+                r = setsockopt(fd, SOL_IP, sa.sa.sa_family == AF_INET ? IP_RECVERR : IPV6_RECVERR, &const_int_one, sizeof(const_int_one));
+                if (r < 0)
+                        return -errno;
+        }
+
         if (ret_socket_address)
                 *ret_socket_address = sa;
         else {