From 147cdce70b22ae7cee9fb4fe123db40952f31c9e Mon Sep 17 00:00:00 2001

From: David Zeuthen <zeuthen@chromium.org>

Date: Tue, 5 Mar 2013 11:52:38 -0800

Subject: [PATCH 8/8] avahi-daemon: add option "host-name-from-machine-id="

Signed-off-by: David Zeuthen <zeuthen@chromium.org>

---

 avahi-daemon/main.c            | 33 +++++++++++++++++++++++++++++++++

 man/avahi-daemon.conf.5.xml.in |  6 ++++++

 2 files changed, 39 insertions(+)

diff --git a/avahi-daemon/main.c b/avahi-daemon/main.c

index d46f40a..8c28fd6 100644

--- a/avahi-daemon/main.c

+++ b/avahi-daemon/main.c

@@ -65,6 +65,7 @@

 #include <avahi-core/publish.h>

 #include <avahi-core/dns-srv-rr.h>

 #include <avahi-core/log.h>

+#include <avahi-core/util.h>

 #ifdef ENABLE_CHROOT

 #include "chroot.h"

@@ -576,6 +577,29 @@ static int parse_usec(const char *s, AvahiUsec *u) {

     return 0;

 }

+static char *get_machine_id(void) {

+    int fd;

+    char buf[32];

+

+    fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);

+    if (fd == -1 && errno == ENOENT)

+        fd = open("/var/lib/dbus/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);

+    if (fd == -1)

+        return NULL;

+

+    /* File is on a filesystem so we never get EINTR or partial reads */

+    if (read(fd, buf, sizeof buf) != sizeof buf) {

+        close(fd);

+        return NULL;

+    }

+    close(fd);

+

+    /* Contents can be lower, upper and even mixed case so normalize */

+    avahi_strdown(buf);

+

+    return avahi_strndup(buf, sizeof buf);

+}

+

 static int load_config_file(DaemonConfig *c) {

     int r = -1;

     AvahiIniFile *f;

@@ -631,6 +655,15 @@ static int load_config_file(DaemonConfig *c) {

                     c->server_config.use_iff_running = is_yes(p->value);

                 else if (strcasecmp(p->key, "disallow-other-stacks") == 0)

                     c->server_config.disallow_other_stacks = is_yes(p->value);

+                else if (strcasecmp(p->key, "host-name-from-machine-id") == 0) {

+                    if (*(p->value) == 'y' || *(p->value) == 'Y') {

+                        char *machine_id = get_machine_id();

+                        if (machine_id != NULL) {

+                            avahi_free(c->server_config.host_name);

+                            c->server_config.host_name = machine_id;

+                        }

+                    }

+                }

 #ifdef HAVE_DBUS

                 else if (strcasecmp(p->key, "enable-dbus") == 0) {

diff --git a/man/avahi-daemon.conf.5.xml.in b/man/avahi-daemon.conf.5.xml.in

index bea7ed5..2d15017 100644

--- a/man/avahi-daemon.conf.5.xml.in

+++ b/man/avahi-daemon.conf.5.xml.in

@@ -40,6 +40,12 @@

     </option>

     <option>

+      
<opt>host-name-from-machine-id=</opt> Takes a boolean

+      value ("yes" or "no"). If set to "yes" avahi-daemon

+      will use the machine-id as name on the LAN.

+    </option>

+

+    <option>

       
<opt>domain-name=</opt> Set the default domain name avahi-daemon

       tries to register its host name and services on the LAN in. If

       omitted defaults to ".local".

-- 

1.9.3