core: better handle sd-resolved errors when resolving hostnames

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/833
This commit is contained in:
Beniamino Galvani 2021-10-29 17:00:59 +02:00
parent 8594b59280
commit 0130e35f80
2 changed files with 61 additions and 2 deletions

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@ -0,0 +1,56 @@
From 61239e69c698b1aff96a3510b6a2324316017693 Mon Sep 17 00:00:00 2001
From: Beniamino Galvani <bgalvani@redhat.com>
Date: Thu, 28 Oct 2021 17:20:12 +0200
Subject: [PATCH] core: better handle sd-resolved errors when resolving
hostnames
If NM tries to resolve a link-local address, systemd-resolved returns
error "org.freedesktop.resolve1.NoNameServers" because those addresses
can only be resolved via other protocols like LLMNR or mDNS.
Previously NM would fall back to spawning the helper, which would ask
again to systemd-resolved via /etc/resolv.conf. In this way, a
synthetic result (or one obtained not from DNS) would be returned.
We must avoid non-DNS results. When systemd-resolved returns an error
that is not a D-Bus one (as MethodNotFound) but is a
"org.fd.resolve1.*" [1], we can assume that systemd-resolved is
running properly and we shall never fall back to spawning the helper.
[1] https://www.freedesktop.org/wiki/Software/systemd/resolved/#commonerrors
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues/833
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1006
(cherry picked from commit d8186b1253a2e0fe88eb06bede17f4892b4270c1)
(cherry picked from commit 77a2a53e8abf25b57fd9dc16ca6a81b6f609d6c1)
---
src/core/devices/nm-device-utils.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/src/core/devices/nm-device-utils.c b/src/core/devices/nm-device-utils.c
index f40ca570f6..75b803de4f 100644
--- a/src/core/devices/nm-device-utils.c
+++ b/src/core/devices/nm-device-utils.c
@@ -267,7 +267,18 @@ resolve_addr_resolved_cb(NMDnsSystemdResolved * resolved,
_LOG2D(info, "error resolving via systemd-resolved: %s", error->message);
dbus_error = g_dbus_error_get_remote_error(error);
- if (nm_streq0(dbus_error, "org.freedesktop.resolve1.DnsError.NXDOMAIN")) {
+ if (NM_STR_HAS_PREFIX(dbus_error, "org.freedesktop.resolve1.")) {
+ /* systemd-resolved is enabled but it couldn't resolve the
+ * address via DNS. Don't fall back to spawning the helper,
+ * because the helper will possibly ask again to
+ * systemd-resolved (via /etc/resolv.conf), potentially using
+ * other protocols than DNS or returning synthetic results.
+ *
+ * Consider the error as the final indication that the address
+ * can't be resolved.
+ *
+ * See: https://www.freedesktop.org/wiki/Software/systemd/resolved/#commonerrors
+ */
resolve_addr_complete(info, NULL, g_error_copy(error));
return;
}
--
2.31.1

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@ -7,7 +7,7 @@
%global epoch_version 1 %global epoch_version 1
%global rpm_version 1.32.12 %global rpm_version 1.32.12
%global real_version 1.32.12 %global real_version 1.32.12
%global release_version 1 %global release_version 2
%global snapshot %{nil} %global snapshot %{nil}
%global git_sha %{nil} %global git_sha %{nil}
@ -185,7 +185,7 @@ Source4: 20-connectivity-fedora.conf
Source5: 20-connectivity-redhat.conf Source5: 20-connectivity-redhat.conf
Source6: 70-nm-connectivity.conf Source6: 70-nm-connectivity.conf
# Patch0001: 0001-some.patch Patch0001: 0001-core-better-handle-sd-resolved-errors-when-resolving.patch
Requires(post): systemd Requires(post): systemd
Requires(post): /usr/sbin/update-alternatives Requires(post): /usr/sbin/update-alternatives
@ -1149,6 +1149,9 @@ fi
%changelog %changelog
* Fri Oct 29 2021 Beniamino Galvani <bgalvani@redhat.com> - 1:1.32.12-2
- better handle systemd-resolved errors when resolving hostnames
* Wed Sep 22 2021 Beniamino Galvani <bgalvani@redhat.com> - 1:1.32.12-1 * Wed Sep 22 2021 Beniamino Galvani <bgalvani@redhat.com> - 1:1.32.12-1
- update to 1.32.12 release - update to 1.32.12 release