fix bad memory access

[catta] / avahi-core / server.c

diff --git a/avahi-core/server.c b/avahi-core/server.c
index dbb861d254e4ed230e9d1885775182ac8ce5d8c1..625af50f349cbe911ef9043721e6eb7ea5695f6f 100644 (file)
--- 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>
@@ -295,7 +296,30 @@ static int handle_conflict(AvahiServer *s, AvahiInterface *i, AvahiRecord *recor
     for (e = avahi_hashmap_lookup(s->entries_by_key, record->key); e; e = n) {
         n = e->by_key_next;
 
-        if (e->dead || (!(e->flags & AVAHI_ENTRY_UNIQUE) && !unique))
+        if (e->dead)
+            continue;
+
+        /* Check if the incoming is a goodbye record */
+        if (avahi_record_is_goodbye(record)) {
+
+            if (avahi_record_equal_no_ttl(e->record, record)) {
+                char *t;
+
+                /* Refresh */
+                t = avahi_record_to_string(record); 
+                avahi_log_debug("Recieved goodbye record for one of our records [%s]. Refreshing.", t);
+                avahi_server_prepare_matching_responses(s, i, e->record->key, 0);
+
+                valid = 0;
+                avahi_free(t);
+                break;
+            }
+
+            /* If the goodybe packet doesn't match one of our own RRs, we simply ignore it. */
+            continue;
+        }
+        
+        if (!(e->flags & AVAHI_ENTRY_UNIQUE) && !unique)
             continue;
 
         /* Either our entry or the other is intended to be unique, so let's check */
@@ -1388,6 +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();
@@ -1826,6 +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,
@@ -1896,6 +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;
 
@@ -2366,6 +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;
 }
@@ -2412,3 +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;
+}