Changeset 92108 in vbox

Timestamp:

Oct 27, 2021 2:54:48 PM (3 years ago)

Author:

vboxsync

Message:

Devics/Network/slirp: Switch to the DNS proxy in case the local resolv.conf contains the loopback interface as the nameserver when access to the loopback interface is blocked, bugref:9896

File:

• trunk/src/VBox/Devices/Network/slirp/slirp_dns.c (modified) (1 diff)

trunk/src/VBox/Devices/Network/slirp/slirp_dns.c

@@ -198 +198 @@
              * because DNS proxy we do revert it back actually.
              */
-            if (address->IPv4.u == RT_N2H_U32_C(INADDR_LOOPBACK))
+            if (   address->IPv4.u == RT_N2H_U32_C(INADDR_LOOPBACK)
+                && pData->fLocalhostReachable)
                 address->IPv4.u = RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) | CTL_ALIAS);
             else if (pData->fUseDnsProxy == 0) {
-                /* We detects that using some address in 127/8 network */
-                LogRel(("NAT: DNS server %RTnaipv4 registration detected, switching to the DNS proxy\n", address->IPv4));
+                /*
+                 * Either the resolver lives somewhere else on the 127/8 network or the loopback interface
+                 * is blocked for access from the guest, either way switch to the DNS proxy.
+                 */
+                if (pData->fLocalhostReachable)
+                    LogRel(("NAT: DNS server %RTnaipv4 registration detected, switching to the DNS proxy\n", address->IPv4));
+                else
+                    LogRel(("NAT: Switching to DNS proxying due to access to the loopback interface being blocked\n"));
                 pData->fUseDnsProxy = 1;
             }