* Beef up host name and address resolvers to notify about RR changes (Similar to what already is available for the service resolver)

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@388 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

4 files changed, 165 insertions, 60 deletions

diff --git a/avahi-core/core.h b/avahi-core/core.h
index 2f55d73..1cf35fc 100644
--- a/avahi-core/core.h
+++ b/avahi-core/core.h
@@ -506,7 +506,7 @@ typedef void (*AvahiSServiceResolverCallback)(
     AvahiSServiceResolver *r,
     AvahiIfIndex interface,
     AvahiProtocol protocol,
-    AvahiResolverEvent event,
+    AvahiResolverEvent event,  /**< Is AVAHI_RESOLVER_FOUND when the service was resolved successfully, and everytime it changes. Is AVAHI_RESOLVER_TIMOUT when the service failed to resolve or disappeared. */
     const char *name,       /**< Service name */
     const char *type,       /**< Service Type */
     const char *domain,
@@ -516,7 +516,7 @@ typedef void (*AvahiSServiceResolverCallback)(
     AvahiStringList *txt,    /**< TXT record data */
     void* userdata);
 
-/** Create a new AvahiSServiceResolver object */
+/** Create a new AvahiSServiceResolver object. The specified callback function will be called with the resolved service data. */
 AvahiSServiceResolver *avahi_s_service_resolver_new(
     AvahiServer *server,
     AvahiIfIndex interface,
diff --git a/avahi-core/resolve-address.c b/avahi-core/resolve-address.c
index 07902e6..fbf50ff 100644
--- a/avahi-core/resolve-address.c
+++ b/avahi-core/resolve-address.c
@@ -29,6 +29,8 @@
 
 #include "browse.h"
 
+#define TIMEOUT_MSEC 1000
+
 struct AvahiSAddressResolver {
     AvahiServer *server;
     AvahiAddress address;
@@ -38,54 +40,102 @@ struct AvahiSAddressResolver {
     AvahiSAddressResolverCallback callback;
     void* userdata;
 
+    AvahiRecord *ptr_record;
+    AvahiIfIndex interface;
+    AvahiProtocol protocol;
+
     AvahiTimeEvent *time_event;
 
     AVAHI_LLIST_FIELDS(AvahiSAddressResolver, resolver);
 };
 
-static void finish(AvahiSAddressResolver *r, AvahiIfIndex interface, AvahiProtocol protocol, AvahiResolverEvent event, AvahiRecord *record) {
+static void finish(AvahiSAddressResolver *r, AvahiResolverEvent event) {
     assert(r);
     
-    avahi_s_record_browser_free(r->record_browser);
-    r->record_browser = NULL;
-
     if (r->time_event) {
         avahi_time_event_free(r->time_event);
         r->time_event = NULL;
     }
 
-    r->callback(r, interface, protocol, event, &r->address, record ? record->data.ptr.name : NULL, r->userdata);
+    if (event == AVAHI_RESOLVER_TIMEOUT)
+        r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_TIMEOUT, &r->address, NULL, r->userdata);
+    else {
+
+        assert(event == AVAHI_RESOLVER_FOUND);
+        assert(r->ptr_record);
+
+        r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_FOUND, &r->address, r->ptr_record->data.ptr.name, r->userdata);
+    }
 }
 
-static void record_browser_callback(AvahiSRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, void* userdata) {
+static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
     AvahiSAddressResolver *r = userdata;
+    
+    assert(e);
+    assert(r);
 
-    assert(rr);
-    assert(record);
+    finish(r, AVAHI_RESOLVER_TIMEOUT);
+}
+
+static void start_timeout(AvahiSAddressResolver *r) {
+    struct timeval tv;
     assert(r);
 
-    if (!(event == AVAHI_BROWSER_NEW))
+    if (r->time_event)
         return;
 
-    assert(record->key->type == AVAHI_DNS_TYPE_PTR);
-
-    finish(r, interface, protocol, AVAHI_RESOLVER_FOUND, record);
+    avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
+    r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
 }
 
-static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
+static void record_browser_callback(AvahiSRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, void* userdata) {
     AvahiSAddressResolver *r = userdata;
-    
-    assert(e);
+
+    assert(rr);
+    assert(record);
     assert(r);
 
-    finish(r, -1, AVAHI_PROTO_UNSPEC, AVAHI_RESOLVER_TIMEOUT, NULL);
+    assert(record->key->type == AVAHI_DNS_TYPE_PTR);
+
+    if (event == AVAHI_BROWSER_NEW) {
+
+        if (r->interface > 0 && interface != r->interface)
+            return;
+        
+        if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
+            return;
+        
+        if (r->interface <= 0)
+            r->interface = interface;
+        
+        if (r->protocol == AVAHI_PROTO_UNSPEC)
+            r->protocol = protocol;
+        
+        if (!r->ptr_record) {
+            r->ptr_record = avahi_record_ref(record);
+
+            finish(r, AVAHI_RESOLVER_FOUND);
+        }
+
+    } else {
+        
+        assert(event == AVAHI_BROWSER_REMOVE);
+        
+        if (avahi_record_equal_no_ttl(record, r->ptr_record)) {
+            avahi_record_unref(r->ptr_record);
+            r->ptr_record = NULL;
+
+            /** Look for a replacement */
+            avahi_s_record_browser_restart(r->record_browser);
+            start_timeout(r);
+        }
+    }
 }
 
 AvahiSAddressResolver *avahi_s_address_resolver_new(AvahiServer *server, AvahiIfIndex interface, AvahiProtocol protocol, const AvahiAddress *address, AvahiSAddressResolverCallback callback, void* userdata) {
     AvahiSAddressResolver *r;
     AvahiKey *k;
     char *n;
-    struct timeval tv;
 
     assert(server);
     assert(address);
@@ -121,17 +171,15 @@ AvahiSAddressResolver *avahi_s_address_resolver_new(AvahiServer *server, AvahiIf
     r->address = *address;
     r->callback = callback;
     r->userdata = userdata;
+    r->ptr_record = NULL;
+    r->interface = interface;
+    r->protocol = protocol;
 
     r->record_browser = NULL;
     AVAHI_LLIST_PREPEND(AvahiSAddressResolver, resolver, server->address_resolvers, r);
 
-    avahi_elapse_time(&tv, 1000, 0);
-    if (!(r->time_event = avahi_time_event_new(server->time_event_queue, &tv, time_event_callback, r))) {
-        avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
-        avahi_s_address_resolver_free(r);
-        avahi_key_unref(k);
-        return NULL;
-    }
+    r->time_event = NULL;
+    start_timeout(r);
     
     r->record_browser = avahi_s_record_browser_new(server, interface, protocol, k, record_browser_callback, r);
     avahi_key_unref(k);
@@ -154,6 +202,9 @@ void avahi_s_address_resolver_free(AvahiSAddressResolver *r) {
 
     if (r->time_event)
         avahi_time_event_free(r->time_event);
+
+    if (r->ptr_record)
+        avahi_record_unref(r->ptr_record);
     
     avahi_free(r);
 }
diff --git a/avahi-core/resolve-host-name.c b/avahi-core/resolve-host-name.c
index 82b0ab4..ae7ef78 100644
--- a/avahi-core/resolve-host-name.c
+++ b/avahi-core/resolve-host-name.c
@@ -23,6 +23,8 @@
 #include <config.h>
 #endif
 
+#include <stdlib.h>
+
 #include <avahi-common/domain.h>
 #include <avahi-common/timeval.h>
 #include <avahi-common/malloc.h>
@@ -31,6 +33,8 @@
 #include "browse.h"
 #include "log.h"
 
+#define TIMEOUT_MSEC 1000
+
 struct AvahiSHostNameResolver {
     AvahiServer *server;
     char *host_name;
@@ -41,49 +45,68 @@ struct AvahiSHostNameResolver {
     AvahiSHostNameResolverCallback callback;
     void* userdata;
 
+    AvahiRecord *address_record;
+    AvahiIfIndex interface;
+    AvahiProtocol protocol;
+
     AvahiTimeEvent *time_event;
 
     AVAHI_LLIST_FIELDS(AvahiSHostNameResolver, resolver);
 };
 
-static void finish(AvahiSHostNameResolver *r, AvahiIfIndex interface, AvahiProtocol protocol, AvahiResolverEvent event, AvahiRecord *record) {
-    AvahiAddress a;
-    
+static void finish(AvahiSHostNameResolver *r, AvahiResolverEvent event) {
     assert(r);
 
-    if (r->record_browser_a) {
-        avahi_s_record_browser_free(r->record_browser_a);
-        r->record_browser_a = NULL;
-    }
-
-    if (r->record_browser_aaaa) {
-        avahi_s_record_browser_free(r->record_browser_aaaa);
-        r->record_browser_aaaa = NULL;
-    }
-
     if (r->time_event) {
         avahi_time_event_free(r->time_event);
         r->time_event = NULL;
     }
 
-    if (record) {
-        switch (record->key->type) {
+    if (event == AVAHI_RESOLVER_TIMEOUT)
+        r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_TIMEOUT, r->host_name, NULL, r->userdata);
+    else {
+        AvahiAddress a;
+    
+        assert(event == AVAHI_RESOLVER_FOUND);
+        assert(r->address_record);
+    
+        switch (r->address_record->key->type) {
             case AVAHI_DNS_TYPE_A:
                 a.family = AVAHI_PROTO_INET;
-                a.data.ipv4 = record->data.a.address;
+                a.data.ipv4 = r->address_record->data.a.address;
                 break;
                 
             case AVAHI_DNS_TYPE_AAAA:
                 a.family = AVAHI_PROTO_INET6;
-                a.data.ipv6 = record->data.aaaa.address;
+                a.data.ipv6 = r->address_record->data.aaaa.address;
                 break;
                 
             default:
-                assert(0);
+                abort();
         }
+
+        r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_FOUND, r->address_record->key->name, &a, r->userdata);
     }
+}
+
+static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
+    AvahiSHostNameResolver *r = userdata;
+    
+    assert(e);
+    assert(r);
 
-    r->callback(r, interface, protocol, event, record ? record->key->name : r->host_name, record ? &a : NULL, r->userdata);
+    finish(r, AVAHI_RESOLVER_TIMEOUT);
+}
+
+static void start_timeout(AvahiSHostNameResolver *r) {
+    struct timeval tv;
+    assert(r);
+
+    if (r->time_event)
+        return;
+
+    avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
+    r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
 }
 
 static void record_browser_callback(AvahiSRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, void* userdata) {
@@ -93,26 +116,49 @@ static void record_browser_callback(AvahiSRecordBrowser*rr, AvahiIfIndex interfa
     assert(record);
     assert(r);
 
-    if (!(event == AVAHI_BROWSER_NEW))
-        return;
-    
     assert(record->key->type == AVAHI_DNS_TYPE_A || record->key->type == AVAHI_DNS_TYPE_AAAA);
-    finish(r, interface, protocol, AVAHI_RESOLVER_FOUND, record);
-}
-
-static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
-    AvahiSHostNameResolver *r = userdata;
     
-    assert(e);
-    assert(r);
+    if (event == AVAHI_BROWSER_NEW) {
 
-    finish(r, -1, AVAHI_PROTO_UNSPEC, AVAHI_RESOLVER_TIMEOUT, NULL);
+        if (r->interface > 0 && interface != r->interface)
+            return;
+        
+        if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
+            return;
+        
+        if (r->interface <= 0)
+            r->interface = interface;
+        
+        if (r->protocol == AVAHI_PROTO_UNSPEC)
+            r->protocol = protocol;
+        
+        if (!r->address_record) {
+            r->address_record = avahi_record_ref(record);
+            
+            finish(r, AVAHI_RESOLVER_FOUND);
+        }
+    } else {
+
+        assert(event == AVAHI_BROWSER_REMOVE);
+
+        if (avahi_record_equal_no_ttl(record, r->address_record)) {
+            avahi_record_unref(r->address_record);
+            r->address_record = NULL;
+
+            /** Look for a replacement */
+            if (r->record_browser_aaaa)
+                avahi_s_record_browser_restart(r->record_browser_aaaa);
+            if (r->record_browser_a)
+                avahi_s_record_browser_restart(r->record_browser_a);
+
+            start_timeout(r);
+        }
+    }
 }
 
 AvahiSHostNameResolver *avahi_s_host_name_resolver_new(AvahiServer *server, AvahiIfIndex interface, AvahiProtocol protocol, const char *host_name, AvahiProtocol aprotocol, AvahiSHostNameResolverCallback callback, void* userdata) {
     AvahiSHostNameResolver *r;
     AvahiKey *k;
-    struct timeval tv;
     
     assert(server);
     assert(host_name);
@@ -134,11 +180,14 @@ AvahiSHostNameResolver *avahi_s_host_name_resolver_new(AvahiServer *server, Avah
     r->host_name = avahi_normalize_name(host_name);
     r->callback = callback;
     r->userdata = userdata;
+    r->address_record = NULL;
+    r->interface = interface;
+    r->protocol = protocol;
 
     r->record_browser_a = r->record_browser_aaaa = NULL;
-        
-    avahi_elapse_time(&tv, 1000, 0);
-    r->time_event = avahi_time_event_new(server->time_event_queue, &tv, time_event_callback, r);
+
+    r->time_event = NULL;
+    start_timeout(r);
 
     AVAHI_LLIST_PREPEND(AvahiSHostNameResolver, resolver, server->host_name_resolvers, r);
 
@@ -184,6 +233,9 @@ void avahi_s_host_name_resolver_free(AvahiSHostNameResolver *r) {
 
     if (r->time_event)
         avahi_time_event_free(r->time_event);
+
+    if (r->address_record)
+        avahi_record_unref(r->address_record);
     
     avahi_free(r->host_name);
     avahi_free(r);
diff --git a/avahi-core/resolve-service.c b/avahi-core/resolve-service.c
index 347de77..333f257 100644
--- a/avahi-core/resolve-service.c
+++ b/avahi-core/resolve-service.c
@@ -75,6 +75,8 @@ static void finish(AvahiSServiceResolver *r, AvahiResolverEvent event) {
         AvahiAddress a;
         char sn[256], st[256];
         size_t i;
+
+        assert(event == AVAHI_RESOLVER_FOUND);
         
         assert(r->srv_record);
         assert(r->txt_record);