From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 4 Dec 2018 22:18:50 +0000 (+0100)
Subject: resolved: request incoming ifindex for DNS UDP packets, too
X-Git-Tag: v240~122^2~8
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c9e6918257d983d1e8ed3d69420544b05b13ef85;p=thirdparty%2Fsystemd.git

resolved: request incoming ifindex for DNS UDP packets, too

This information is useful to pass back to the caller, as it tells us
where we found the answer.

(While we are at it, fix the socket level for the RECVERR logic)

Fixes: #9778
---

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index ee204435b33..35c3804dbab 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -413,9 +413,25 @@ 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_int(fd, SOL_IP, sa.sa.sa_family == AF_INET ? IP_RECVERR : IPV6_RECVERR, true);
-                if (r < 0)
-                        return r;
+
+                if (sa.sa.sa_family == AF_INET) {
+                        r = setsockopt_int(fd, IPPROTO_IP, IP_RECVERR, true);
+                        if (r < 0)
+                                return r;
+
+                        r = setsockopt_int(fd, IPPROTO_IP, IP_PKTINFO, true);
+                        if (r < 0)
+                                return r;
+
+                } else if (sa.sa.sa_family == AF_INET6) {
+                        r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_RECVERR, true);
+                        if (r < 0)
+                                return r;
+
+                        r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, true);
+                        if (r < 0)
+                                return r;
+                }
         }
 
         if (ret_socket_address)