Add support for advertising services on the local machine only

This patch is not merged upstream yet. However, Ubuntu is already
shipping it. Let's merge it to Fedora too so ippusbxd (which depends on
this functionality) can get packaged to Fedora.

https://github.com/lathiat/avahi/issues/125
https://github.com/lathiat/avahi/pull/161

0001-Add-support-to-advertise-local-services-localhost-on.patch

@@ -0,0 +1,86 @@
+From 9283ba29b23dd6dc7faaf138188fd02ab38b30e8 Mon Sep 17 00:00:00 2001
+From: Till Kamppeter <till.kamppeter@gmail.com>
+Date: Fri, 15 Dec 2017 10:16:28 -0200
+Subject: [PATCH] Add support to advertise local services ("localhost") on the
+ local machine only
+
+This is the patch attached to Issue #125 (on Dec 6, 2017) and also
+shown in the readme.md of ippusbxd
+(https://github.com/OpenPrinting/ippusbxd).
+
+It makes also services on the loopback ("lo") interface being
+advertised and these records use "localhost" instead of the network
+host name of the machine as server host name. This way clients, like
+for example CUPS or cups-browsed will find these local services and be
+able to work with them as they were network services.
+---
+ avahi-core/iface-linux.c     | 4 ++--
+ avahi-core/iface-pfroute.c   | 8 ++++----
+ avahi-core/resolve-service.c | 3 ++-
+ 3 files changed, 8 insertions(+), 7 deletions(-)
+
+diff --git a/avahi-core/iface-linux.c b/avahi-core/iface-linux.c
+index c6c5f77..e116c7b 100644
+--- a/avahi-core/iface-linux.c
++++ b/avahi-core/iface-linux.c
+@@ -104,8 +104,8 @@ static void netlink_callback(AvahiNetlink *nl, struct nlmsghdr *n, void* userdat
+         hw->flags_ok =
+             (ifinfomsg->ifi_flags & IFF_UP) &&
+             (!m->server->config.use_iff_running || (ifinfomsg->ifi_flags & IFF_RUNNING)) &&
+-            !(ifinfomsg->ifi_flags & IFF_LOOPBACK) &&
+-            (ifinfomsg->ifi_flags & IFF_MULTICAST) &&
++            ((ifinfomsg->ifi_flags & IFF_LOOPBACK) ||
++             (ifinfomsg->ifi_flags & IFF_MULTICAST)) &&
+             (m->server->config.allow_point_to_point || !(ifinfomsg->ifi_flags & IFF_POINTOPOINT));
+ 
+         /* Handle interface attributes */
+diff --git a/avahi-core/iface-pfroute.c b/avahi-core/iface-pfroute.c
+index 9a2e953..27c3443 100644
+--- a/avahi-core/iface-pfroute.c
++++ b/avahi-core/iface-pfroute.c
+@@ -80,8 +80,8 @@ static void rtm_info(struct rt_msghdr *rtm, AvahiInterfaceMonitor *m)
+   hw->flags_ok =
+     (ifm->ifm_flags & IFF_UP) &&
+     (!m->server->config.use_iff_running || (ifm->ifm_flags & IFF_RUNNING)) &&
+-    !(ifm->ifm_flags & IFF_LOOPBACK) &&
+-    (ifm->ifm_flags & IFF_MULTICAST) &&
++    ((ifm->ifm_flags & IFF_LOOPBACK) ||
++     (ifm->ifm_flags & IFF_MULTICAST)) &&
+     (m->server->config.allow_point_to_point || !(ifm->ifm_flags & IFF_POINTOPOINT));
+ 
+   avahi_free(hw->name);
+@@ -427,8 +427,8 @@ static void if_add_interface(struct lifreq *lifreq, AvahiInterfaceMonitor *m, in
+         hw->flags_ok =
+             (flags & IFF_UP) &&
+             (!m->server->config.use_iff_running || (flags & IFF_RUNNING)) &&
+-            !(flags & IFF_LOOPBACK) &&
+-            (flags & IFF_MULTICAST) &&
++            ((flags & IFF_LOOPBACK) ||
++             (flags & IFF_MULTICAST)) &&
+             (m->server->config.allow_point_to_point || !(flags & IFF_POINTOPOINT));
+         hw->name = avahi_strdup(lifreq->lifr_name);
+         hw->mtu = mtu;
+diff --git a/avahi-core/resolve-service.c b/avahi-core/resolve-service.c
+index 3377a50..3311b6b 100644
+--- a/avahi-core/resolve-service.c
++++ b/avahi-core/resolve-service.c
+@@ -24,6 +24,7 @@
+ #include <string.h>
+ #include <stdio.h>
+ #include <stdlib.h>
++#include <net/if.h>
+ 
+ #include <avahi-common/domain.h>
+ #include <avahi-common/timeval.h>
+@@ -129,7 +130,7 @@ static void finish(AvahiSServiceResolver *r, AvahiResolverEvent event) {
+                 r->service_name,
+                 r->service_type,
+                 r->domain_name,
+-                r->srv_record->data.srv.name,
++                (r->interface == if_nametoindex("lo")) ? "localhost" : r->srv_record->data.srv.name,
+                 r->address_record ? &a : NULL,
+                 r->srv_record->data.srv.port,
+                 r->txt_record ? r->txt_record->data.txt.string_list : NULL,
+-- 
+2.17.2
+

avahi.spec

@@ -26,7 +26,7 @@
 
 Name:             avahi
 Version:          0.7
-Release:          18%{?dist}
+Release:          19%{?dist}
 Summary:          Local network service discovery
 License:          LGPLv2+
 URL:              http://avahi.org
@@ -92,6 +92,7 @@ Source0:          https://github.com/lathiat/avahi/releases/download/v%{version}
 
 ## downstream patches
 Patch100:         avahi-0.6.30-mono-libdir.patch
+Patch101:         0001-Add-support-to-advertise-local-services-localhost-on.patch
 
 %description
 Avahi is a system which facilitates service discovery on
@@ -697,6 +698,9 @@ exit 0
 
 
 %changelog
+* Fri Feb 22 2019 Michal Sekletár <msekleta@redhat.com> - 0.7-19
+- add support for advertising services on the local machine only (i.e. on loopback)
+
 * Mon Feb 04 2019 Kalev Lember <klember@redhat.com> - 0.7-18
 - Update requires for pygobject3 -> python2-gobject rename