1 files changed, 179 insertions, 0 deletions
diff --git a/tools/xcs/bindings.c b/tools/xcs/bindings.c
new file mode 100644
index 0000000000..9b09f51568
--- /dev/null
+++ b/tools/xcs/bindings.c
@@ -0,0 +1,179 @@
+/* bindings.c
+ *
+ * Manage subscriptions for the control interface switch.
+ *
+ * (c) 2004, Andrew Warfield
+ *
+ */
+
+/* Interfaces:
+ *
+ * xcs_bind   (port, type, connection)
+ *   - Register connection to receive messages of this type.
+ * xcs_unbind (port, type, connection)
+ *   - Remove an existing registration. (Must be an exact match)
+ * xcs_lookup (port, type)
+ *   - Return a list of connections matching a registration.
+ * 
+ * - All connections have a connection.bindings list of current bindings.
+ * - (port, type) pairs may be wildcarded with -1.
+ */
+ 
+#include <stdio.h>
+#include <stdlib.h> 
+#include <errno.h>
+#include <string.h>
+#include "xcs.h"
+
+
+typedef struct binding_ent_st {
+    connection_t          *con;
+    struct binding_ent_st *next;
+} binding_ent_t;
+
+#define BINDING_TABLE_SIZE       1024
+
+static binding_ent_t *binding_table[BINDING_TABLE_SIZE];
+        
+#define PORT_WILD(_ent) ((_ent)->port == PORT_WILDCARD)
+#define TYPE_WILD(_ent) ((_ent)->type == TYPE_WILDCARD)
+#define FULLY_WILD(_ent) (PORT_WILD(_ent) && TYPE_WILD(_ent))
+
+#define BINDING_HASH(_key) \
+    ((((_key)->port * 11) ^ (_key)->type) % BINDING_TABLE_SIZE)
+    
+    
+void init_bindings(void)
+{
+    memset(binding_table, 0, sizeof(binding_table));
+}
+
+static int table_add(binding_ent_t *table[],
+                            connection_t *con, 
+                            binding_key_t *key)
+{
+    binding_ent_t **curs, *ent;
+        
+    curs = &table[BINDING_HASH(key)];
+    
+    while (*curs != NULL) {
+        if ((*curs)->con == con) {
+            DPRINTF("Tried to add an ent that already existed.\n");
+            goto done;
+        }
+        curs = &(*curs)->next;
+    }
+    
+    if (connection_add_binding(con, key) != 0)
+    {
+       DPRINTF("couldn't add binding on connection (%lu)\n", con->id);
+       goto fail;
+    }
+    ent = (binding_ent_t *)malloc(sizeof(binding_ent_t));
+    if (ent == 0) {
+       DPRINTF("couldn't alloc binding ent!\n");
+       goto fail;
+    }
+    ent->con = con;
+    ent->next = NULL;
+    *curs = ent;
+    
+done:
+    return 0;
+
+fail:
+    return -1;
+}
+
+
+static inline int binding_has_colliding_hashes(connection_t *con, 
+                                               binding_key_t *key)
+{
+    int hash, count = 0;
+    binding_key_ent_t *ent;
+    
+    ent = con->bindings; 
+    hash = BINDING_HASH(key);
+    
+    while (ent != NULL) {
+        if (BINDING_HASH(&ent->key) == hash) count ++;
+        ent = ent->next;
+    }
+    
+    return (count > 1);
+}
+static int table_remove(binding_ent_t *table[],
+                            connection_t *con, 
+                            binding_key_t *key)
+{
+    binding_ent_t **curs, *ent;
+    
+    if (!binding_has_colliding_hashes(con, key))
+    {
+    
+        curs = &table[BINDING_HASH(key)];
+
+        while ((*curs != NULL) && ((*curs)->con != con))
+           curs = &(*curs)->next;
+
+        if (*curs != NULL) {
+           ent = *curs;
+           *curs = (*curs)->next;
+           free(ent);
+        }
+    }
+    
+    connection_remove_binding(con, key);
+    
+    return 0;    
+}
+
+int xcs_bind(connection_t *con, int port, u16 type)
+{
+    binding_key_t  key;
+    
+    key.port = port;
+    key.type = type;
+    
+    return table_add(binding_table, con, &key);  
+}
+
+int xcs_unbind(connection_t *con, int port, u16 type)
+{
+    binding_key_t  key;
+    
+    key.port = port;
+    key.type = type;
+    
+    return table_remove(binding_table, con, &key); 
+}
+
+
+static void for_each_binding(binding_ent_t *list, binding_key_t *key, 
+                void (*f)(connection_t *, void *), void *arg)
+{
+    while (list != NULL) 
+    {
+        if (connection_has_binding(list->con, key))
+            f(list->con, arg);
+        list = list->next;
+    }  
+}
+
+void xcs_lookup(int port, u16 type, void (*f)(connection_t *, void *), 
+                void *arg)
+{
+    binding_key_t  key;
+            
+    key.port  = port; key.type = type;
+    for_each_binding(binding_table[BINDING_HASH(&key)], &key, f, arg);
+            
+    key.port  = port; key.type = TYPE_WILDCARD;
+    for_each_binding(binding_table[BINDING_HASH(&key)], &key, f, arg);
+            
+    key.port  = PORT_WILDCARD; key.type = type;
+    for_each_binding(binding_table[BINDING_HASH(&key)], &key, f, arg);
+            
+    key.port  = PORT_WILDCARD; key.type = TYPE_WILDCARD;
+    for_each_binding(binding_table[BINDING_HASH(&key)], &key, f, arg);
+}