From e8edcf439d2ce1593af11c357893681b6b3c0bb4 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Sat, 10 Sep 2005 00:22:30 +0000
Subject: * add magic identification cookies to service TXT records
 automatically * add an API to query the local service cookie * add a DBUS
 interface to query the local service cookie * wrap that in avahi-client

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@555 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe
---
 avahi-core/core.h   |  4 ++++
 avahi-core/server.c | 29 +++++++++++++++++++++++++++++
 avahi-core/server.h |  2 ++
 3 files changed, 35 insertions(+)

(limited to 'avahi-core')

diff --git a/avahi-core/core.h b/avahi-core/core.h
index 1cf35fc..427a09a 100644
--- a/avahi-core/core.h
+++ b/avahi-core/core.h
@@ -85,6 +85,7 @@ typedef struct AvahiServerConfig {
     int use_iff_running;              /**< Require IFF_RUNNING on local network interfaces. This is the official way to check for link beat. Unfortunately this doesn't work with all drivers. So bettere leave this off. */
     int enable_reflector;             /**< Reflect incoming mDNS traffic to all local networks. This allows mDNS based network browsing beyond ethernet borders */
     int reflect_ipv;                  /**< if enable_reflector is 1, enable/disable reflecting between IPv4 and IPv6 */
+    int add_service_cookie;           /**< Add magic service cookie to all locally generated records implicitly */
 } AvahiServerConfig;
 
 /** Allocate a new mDNS responder object. */
@@ -564,6 +565,9 @@ void avahi_s_dns_server_browser_free(AvahiSDNSServerBrowser *b);
 /** Return the last error code */
 int avahi_server_errno(AvahiServer *s);
 
+/** Return the local service cookie */
+uint32_t avahi_server_get_local_service_cookie(AvahiServer *s);
+
 #ifndef DOXYGEN_SHOULD_SKIP_THIS
 AVAHI_C_DECL_END
 #endif
diff --git a/avahi-core/server.c b/avahi-core/server.c
index 66cc705..625af50 100644
--- a/avahi-core/server.c
+++ b/avahi-core/server.c
@@ -31,6 +31,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <assert.h>
+#include <stdlib.h>
 
 #include <avahi-common/domain.h>
 #include <avahi-common/timeval.h>
@@ -1411,6 +1412,10 @@ AvahiServer *avahi_server_new(const AvahiPoll *poll_api, const AvahiServerConfig
 
     s->legacy_unicast_reflect_slots = NULL;
     s->legacy_unicast_reflect_id = 0;
+
+    do {
+        s->local_service_cookie = (uint32_t) rand() * (uint32_t) rand();
+    } while (s->local_service_cookie == AVAHI_SERVICE_COOKIE_INVALID);
     
     /* Get host name */
     s->host_name = s->config.host_name ? avahi_normalize_name(s->config.host_name) : avahi_get_host_name();
@@ -1849,6 +1854,22 @@ static void escape_service_name(char *d, size_t size, const char *s) {
     *(d++) = 0;
 }
 
+static AvahiStringList *add_magic_cookie(
+    AvahiServer *s,
+    AvahiStringList *strlst) {
+
+    assert(s);
+
+    if (!s->config.add_service_cookie)
+        return strlst;
+
+    if (avahi_string_list_find(strlst, AVAHI_SERVICE_COOKIE))
+        /* This string list already contains a magic cookie */
+        return strlst;
+
+    return avahi_string_list_add_printf(strlst, AVAHI_SERVICE_COOKIE"=%u", s->local_service_cookie);
+}
+
 static int server_add_service_strlst_nocopy(
     AvahiServer *s,
     AvahiSEntryGroup *g,
@@ -1919,6 +1940,8 @@ static int server_add_service_strlst_nocopy(
     if (ret < 0)
         goto fail;
 
+    strlst = add_magic_cookie(s, strlst);
+    
     ret = server_add_txt_strlst_nocopy(s, g, interface, protocol, AVAHI_ENTRY_UNIQUE, AVAHI_DEFAULT_TTL, svc_name, strlst);
     strlst = NULL;
 
@@ -2389,6 +2412,7 @@ AvahiServerConfig* avahi_server_config_init(AvahiServerConfig *c) {
     c->use_iff_running = 0;
     c->enable_reflector = 0;
     c->reflect_ipv = 0;
+    c->add_service_cookie = 1;
     
     return c;
 }
@@ -2435,3 +2459,8 @@ int avahi_server_set_errno(AvahiServer *s, int error) {
     return s->error = error;
 }
 
+uint32_t avahi_server_get_local_service_cookie(AvahiServer *s) {
+    assert(s);
+
+    return s->local_service_cookie;
+}
diff --git a/avahi-core/server.h b/avahi-core/server.h
index 6ceab42..7384e98 100644
--- a/avahi-core/server.h
+++ b/avahi-core/server.h
@@ -139,6 +139,8 @@ struct AvahiServer {
     uint16_t legacy_unicast_reflect_id;
 
     int error;
+
+    uint32_t local_service_cookie;
 };
 
 int avahi_server_entry_match_interface(AvahiEntry *e, AvahiInterface *i);
-- 
cgit