Add back 802.1D Spanning Tree Protocol (STP) library code.

[openvswitch] / lib / stp.h

diff --git a/lib/stp.h b/lib/stp.h
new file mode 100644 (file)
index 0000000..7eb2cb9
--- /dev/null
+++ b/lib/stp.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2008, 2011 Nicira Networks.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef STP_H
+#define STP_H 1
+
+/* This is an implementation of Spanning Tree Protocol as described in IEEE
+ * 802.1D-1998, clauses 8 and 9.  Section numbers refer to this standard.  */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "compiler.h"
+#include "util.h"
+
+struct ofpbuf;
+
+/* LLC field values used for STP frames. */
+#define STP_LLC_SSAP 0x42
+#define STP_LLC_DSAP 0x42
+#define STP_LLC_CNTL 0x03
+
+/* Bridge and port priorities that should be used by default. */
+#define STP_DEFAULT_BRIDGE_PRIORITY 32768
+#define STP_DEFAULT_PORT_PRIORITY 128
+
+/* Bridge identifier.  Top 16 bits are a priority value (numerically lower
+ * values are higher priorities).  Bottom 48 bits are MAC address of bridge. */
+typedef uint64_t stp_identifier;
+
+/* Basic STP functionality. */
+#define STP_MAX_PORTS 255
+struct stp *stp_create(const char *name, stp_identifier bridge_id,
+                       void (*send_bpdu)(struct ofpbuf *bpdu, int port_no,
+                                         void *aux),
+                       void *aux);
+void stp_destroy(struct stp *);
+void stp_tick(struct stp *, int ms);
+void stp_set_bridge_id(struct stp *, stp_identifier bridge_id);
+void stp_set_bridge_priority(struct stp *, uint16_t new_priority);
+void stp_set_hello_time(struct stp *, int ms);
+void stp_set_max_age(struct stp *, int ms);
+void stp_set_forward_delay(struct stp *, int ms);
+
+/* STP properties. */
+const char *stp_get_name(const struct stp *);
+stp_identifier stp_get_bridge_id(const struct stp *);
+stp_identifier stp_get_designated_root(const struct stp *);
+bool stp_is_root_bridge(const struct stp *);
+int stp_get_root_path_cost(const struct stp *);
+int stp_get_hello_time(const struct stp *);
+int stp_get_max_age(const struct stp *);
+int stp_get_forward_delay(const struct stp *);
+
+/* Obtaining STP ports. */
+struct stp_port *stp_get_port(struct stp *, int port_no);
+struct stp_port *stp_get_root_port(struct stp *);
+bool stp_get_changed_port(struct stp *, struct stp_port **portp);
+
+/* State of an STP port.
+ *
+ * A port is in exactly one state at any given time, but distinct bits are used
+ * for states to allow testing for more than one state with a bit mask. */
+enum stp_state {
+    STP_DISABLED = 1 << 0,       /* 8.4.5: Disabled by management. */
+    STP_LISTENING = 1 << 1,      /* 8.4.2: Not learning or relaying frames. */
+    STP_LEARNING = 1 << 2,       /* 8.4.3: Learning but not relaying frames. */
+    STP_FORWARDING = 1 << 3,     /* 8.4.4: Learning and relaying frames. */
+    STP_BLOCKING = 1 << 4        /* 8.4.1: Initial boot state. */
+};
+const char *stp_state_name(enum stp_state);
+bool stp_forward_in_state(enum stp_state);
+bool stp_learn_in_state(enum stp_state);
+
+void stp_received_bpdu(struct stp_port *, const void *bpdu, size_t bpdu_size);
+
+struct stp *stp_port_get_stp(struct stp_port *);
+int stp_port_no(const struct stp_port *);
+enum stp_state stp_port_get_state(const struct stp_port *);
+void stp_port_enable(struct stp_port *);
+void stp_port_disable(struct stp_port *);
+void stp_port_set_priority(struct stp_port *, uint8_t new_priority);
+void stp_port_set_path_cost(struct stp_port *, uint16_t path_cost);
+void stp_port_set_speed(struct stp_port *, unsigned int speed);
+void stp_port_enable_change_detection(struct stp_port *);
+void stp_port_disable_change_detection(struct stp_port *);
+
+#endif /* stp.h */