openflow_input: add bsn_gentable extension and tests

See the documentation in openflow_input/bsn_gentable.
diff --git a/openflow_input/bsn_gentable b/openflow_input/bsn_gentable
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+// Copyright 2013, Big Switch Networks, Inc.
+//
+// LoxiGen is licensed under the Eclipse Public License,
+// version 1.0 (EPL), with the following special exception:
+//
+// LOXI Exception
+//
+// As a special exception to the terms of the EPL, you may
+// distribute libraries generated by LoxiGen (LoxiGen Libraries)
+// under the terms of your choice, provided that copyright and
+// licensing notices generated by LoxiGen are not altered or removed
+// from the LoxiGen Libraries and the notice provided below is (i)
+// included in the LoxiGen Libraries, if distributed in source code
+// form and (ii) included in any documentation for the LoxiGen
+// Libraries, if distributed in binary form.
+//
+// Notice: "Copyright 2013, Big Switch Networks, Inc.
+// This library was generated by the LoxiGen Compiler."
+//
+// You may not use this file except in compliance with the EPL or
+// LOXI Exception. You may obtain a copy of the EPL at:
+//
+// http://www.eclipse.org/legal/epl-v10.html
+//
+// 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 EPL for the specific language
+// governing permissions and limitations under the EPL.
+
+#version 4
+
+// We have a number of switch agents that need to be configured by the
+// controller and report stats. Some of them will have large tables (1000+
+// entries) and so need an efficient synchronization mechanism (as can be
+// accomplished using the cookie field in flowtable entries). It's a
+// significant amount of work to do this from scratch for each new table.
+// This extension (and the corresponding Indigo code) provides a framework
+// to ease implementing new tables.
+
+// We don't plan on replacing our use of the OpenFlow flow table and group
+// table with this scheme. This is intended for controlling switch
+// functionality like the ARP and LACP agents which don't map at all to
+// flow-mods.
+
+// Each switch will have a number of tables indexed by a 16-bit table ID. Each
+// table has a name, id, a set of entries, and an array of checksum buckets.
+// There is no order to the entries; stats requests will return them in an
+// arbitrary order. The controller is expected to use the table name to
+// determine the semantics of a table.
+
+// Each entry has a key, value, stats, and checksum. The key and value are TLV
+// lists given by the controller in a gentable_entry_add message. The switch must
+// return these lists in stats replies exactly as it received them. The stats
+// are a list of TLVs controlled by the switch. The stats are expected to
+// include more than simple counters (for example, last hit time or seen TCP
+// flags). The checksum is an opaque value used for table synchronization.
+
+// LOXI includes a built-in type of_checksum_128_t, which is 128 bits but
+// only requires 32-bit alignment.
+
+
+// These TLV classes are used for keys, values, and stats. Like OXM, lists of
+// TLVs are tightly packed without padding. TLV lists may include duplicates
+// and the semantics of this is left to the particular table.
+//
+// If this is eventually standardized it would be good to add a "class" type
+// member as in OXM.
+struct of_bsn_tlv {
+    uint16_t type == ?;
+    uint16_t length;
+};
+
+
+// This message sets key=value in the given table. If key already exists in the
+// table then it modifies the value, preserving stats.
+//
+// If the switch cannot process the message then it should reply with an error
+// message. The contents of the table must not be changed in case of an error.
+struct of_bsn_gentable_entry_add : of_bsn_header {
+    uint8_t version;
+    uint8_t type == 4;
+    uint16_t length;
+    uint32_t xid;
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 46;
+    uint16_t table_id;
+    uint16_t key_length;
+    of_checksum_128_t checksum;
+    list(of_bsn_tlv_t) key;
+    list(of_bsn_tlv_t) value;
+};
+
+
+// This message deletes the entry with the given key in the given table.
+//
+// If the switch cannot process the message then it should reply with an error
+// message. The contents of the table must not be changed in case of an error.
+struct of_bsn_gentable_entry_delete : of_bsn_header {
+    uint8_t version;
+    uint8_t type == 4;
+    uint16_t length;
+    uint32_t xid;
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 47;
+    uint16_t table_id;
+    list(of_bsn_tlv_t) key;
+};
+
+
+// This message deletes a range of table entries. The checksum_mask must be a
+// prefix mask. The checksum must be zero in the bits where the checksum_mask
+// is zero.
+//
+// The switch may fail to delete some table entries. No error messages will be
+// sent, but the error_count in the reply message will be incremented.
+struct of_bsn_gentable_clear_request : of_bsn_header {
+    uint8_t version;
+    uint8_t type == 4;
+    uint16_t length;
+    uint32_t xid;
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 48;
+    uint16_t table_id;
+    pad(2);
+    of_checksum_128_t checksum;
+    of_checksum_128_t checksum_mask;
+};
+
+struct of_bsn_gentable_clear_reply : of_bsn_header {
+    uint8_t version;
+    uint8_t type == 4;
+    uint16_t length;
+    uint32_t xid;
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 49;
+    uint16_t table_id;
+    pad(2);
+    uint32_t deleted_count;
+    uint32_t error_count;
+};
+
+
+// This message sets the size of the buckets array. The switch may reject this
+// message if the table has entries.
+struct of_bsn_gentable_set_buckets_size : of_bsn_header {
+    uint8_t version;
+    uint8_t type == 4;
+    uint16_t length;
+    uint32_t xid;
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 50;
+    uint16_t table_id;
+    pad(2);
+    uint32_t buckets_size;
+};
+
+
+// Retrieve the configuration state (key, value, and checksum) for each table
+// entry in a range of buckets.
+//
+// The checksum_mask must be a prefix mask. The checksum must be zero in the
+// bits where the checksum_mask is zero.
+struct of_bsn_gentable_entry_desc_stats_request : of_bsn_stats_request {
+    uint8_t version;
+    uint8_t type == 18;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_request_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 2;
+    uint16_t table_id;
+    pad(2);
+    of_checksum_128_t checksum;
+    of_checksum_128_t checksum_mask;
+};
+
+struct of_bsn_gentable_entry_desc_stats_entry {
+    uint16_t length;
+    uint16_t key_length;
+    of_checksum_128_t checksum;
+    list(of_bsn_tlv_t) key;
+    list(of_bsn_tlv_t) value;
+};
+
+struct of_bsn_gentable_entry_desc_stats_reply : of_bsn_stats_reply {
+    uint8_t version;
+    uint8_t type == 19;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_reply_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 2;
+    list(of_bsn_gentable_entry_desc_stats_entry_t) entries;
+};
+
+
+// Retrieve the runtime state (key and stats) for each table entry in a range
+// of buckets.
+//
+// The checksum_mask must be a prefix mask. The checksum must be zero in the
+// bits where the checksum_mask is zero.
+struct of_bsn_gentable_entry_stats_request : of_bsn_stats_request {
+    uint8_t version;
+    uint8_t type == 18;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_request_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 3;
+    uint16_t table_id;
+    pad(2);
+    of_checksum_128_t checksum;
+    of_checksum_128_t checksum_mask;
+};
+
+struct of_bsn_gentable_entry_stats_entry {
+    uint16_t length;
+    uint16_t key_length;
+    list(of_bsn_tlv_t) key;
+    list(of_bsn_tlv_t) stats;
+};
+
+struct of_bsn_gentable_entry_stats_reply : of_bsn_stats_reply {
+    uint8_t version;
+    uint8_t type == 19;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_reply_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 3;
+    list(of_bsn_gentable_entry_stats_entry_t) entries;
+};
+
+
+// Retrieve the description for all tables.
+struct of_bsn_gentable_desc_stats_request : of_bsn_stats_request {
+    uint8_t version;
+    uint8_t type == 18;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_request_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 4;
+};
+
+struct of_bsn_gentable_desc_stats_entry {
+    uint16_t length;
+    uint16_t table_id;
+    of_table_name_t name;
+    uint32_t buckets_size;
+    /* TODO properties */
+};
+
+struct of_bsn_gentable_desc_stats_reply : of_bsn_stats_reply {
+    uint8_t version;
+    uint8_t type == 19;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_reply_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 4;
+    list(of_bsn_gentable_desc_stats_entry_t) entries;
+};
+
+
+// Retrieves stats for every table. This includes the total checksum, so the
+// controller can quickly check whether the whole table is in sync.
+//
+// The checksum of a table is the XOR of the checksums of all entries in the
+// table.
+struct of_bsn_gentable_stats_request : of_bsn_stats_request {
+    uint8_t version;
+    uint8_t type == 18;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_request_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 7;
+};
+
+struct of_bsn_gentable_stats_entry {
+    uint16_t table_id;
+    pad(2);
+    uint32_t entry_count;
+    of_checksum_128_t checksum;
+};
+
+struct of_bsn_gentable_stats_reply : of_bsn_stats_reply {
+    uint8_t version;
+    uint8_t type == 19;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_reply_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 7;
+    list(of_bsn_gentable_stats_entry_t) entries;
+};
+
+
+// Retrieves the checksum for every bucket in a table. The entries are ordered
+// by bucket index.
+//
+// The checksum of a bucket is the XOR of the checksums of all entries in the
+// bucket.
+struct of_bsn_gentable_bucket_stats_request : of_bsn_stats_request {
+    uint8_t version;
+    uint8_t type == 18;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_request_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 5;
+    uint16_t table_id;
+};
+
+struct of_bsn_gentable_bucket_stats_entry {
+    of_checksum_128_t checksum;
+};
+
+struct of_bsn_gentable_bucket_stats_reply : of_bsn_stats_reply {
+    uint8_t version;
+    uint8_t type == 19;
+    uint16_t length;
+    uint32_t xid;
+    uint16_t stats_type == 0xffff;
+    enum ofp_stats_reply_flags flags;
+    pad(4);
+    uint32_t experimenter == 0x5c16c7;
+    uint32_t subtype == 5;
+    list(of_bsn_gentable_bucket_stats_entry_t) entries;
+};