trema/trema-edge

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src/lib/openflow.h

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/*
 * Copyright (C) 2013 NEC Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */


/* OpenFlow: protocol between controller and datapath. */

#ifndef OPENFLOW_H
#define OPENFLOW_H 1

#include <stdint.h>


#if !defined(__cplusplus)
/* Build-time assertion for use in a declaration context. */
#define OFP_ASSERT(EXPR)                                                \
        extern int (*build_assert(void))[ sizeof(struct {               \
                    unsigned int build_assert_failed : (EXPR) ? 1 : -1; })]
#else
#define OFP_ASSERT(_EXPR) typedef int build_assert_failed[(_EXPR) ? 1 : -1]
#endif


/* Official IANA registered port for OpenFlow. */
#define OFP_TCP_PORT  6653
#define OFP_SSL_PORT  6653


// 7.1  OpenFlow Header

/* Header on all OpenFlow packets. */
struct ofp_header {
    uint8_t version;    /* OFP_VERSION. */
    uint8_t type;       /* One of the OFPT_ constants. */
    uint16_t length;    /* Length including this ofp_header. */
    uint32_t xid;       /* Transaction id associated with this packet.
                           Replies use the same id as was in the request
                           to facilitate pairing. */
};
OFP_ASSERT(sizeof(struct ofp_header) == 8);

/* Version number:
 * Non-experimental versions released: 0x01 = 1.0 ; 0x02 = 1.1 ; 0x03 = 1.2
 * 0x04 = 1.3
 * Experimental versions released: 0x81 -- 0x99
 */
/* The most significant bit being set in the version field indicates an
 * experimental OpenFlow version.
 */
#define OFP_VERSION 0x04

enum ofp_type {
    /* Immutable messages. */
    OFPT_HELLO              = 0,  /* Symmetric message */
    OFPT_ERROR              = 1,  /* Symmetric message */
    OFPT_ECHO_REQUEST       = 2,  /* Symmetric message */
    OFPT_ECHO_REPLY         = 3,  /* Symmetric message */
    OFPT_EXPERIMENTER       = 4,  /* Symmetric message */

    /* Switch configuration messages. */
    OFPT_FEATURES_REQUEST   = 5,  /* Controller/switch message */
    OFPT_FEATURES_REPLY     = 6,  /* Controller/switch message */
    OFPT_GET_CONFIG_REQUEST = 7,  /* Controller/switch message */
    OFPT_GET_CONFIG_REPLY   = 8,  /* Controller/switch message */
    OFPT_SET_CONFIG         = 9,  /* Controller/switch message */

    /* Asynchronous messages. */
    OFPT_PACKET_IN          = 10, /* Async message */
    OFPT_FLOW_REMOVED       = 11, /* Async message */
    OFPT_PORT_STATUS        = 12, /* Async message */

    /* Controller command messages. */
    OFPT_PACKET_OUT         = 13, /* Controller/switch message */
    OFPT_FLOW_MOD           = 14, /* Controller/switch message */
    OFPT_GROUP_MOD          = 15, /* Controller/switch message */
    OFPT_PORT_MOD           = 16, /* Controller/switch message */
    OFPT_TABLE_MOD          = 17, /* Controller/switch message */

    /* Multipart messages. */
    OFPT_MULTIPART_REQUEST  = 18, /* Controller/switch message */
    OFPT_MULTIPART_REPLY    = 19, /* Controller/switch message */

    /* Barrier messages. */
    OFPT_BARRIER_REQUEST    = 20, /* Controller/switch message */
    OFPT_BARRIER_REPLY      = 21, /* Controller/switch message */

    /* Queue Configuration messages. */
    OFPT_QUEUE_GET_CONFIG_REQUEST = 22, /* Controller/switch message */
    OFPT_QUEUE_GET_CONFIG_REPLY   = 23, /* Controller/switch message */

    /* Controller role change request messages. */
    OFPT_ROLE_REQUEST       = 24, /* Controller/switch message */
    OFPT_ROLE_REPLY         = 25, /* Controller/switch message */

    /* Asynchronous message configuration. */
    OFPT_GET_ASYNC_REQUEST  = 26, /* Controller/switch message */
    OFPT_GET_ASYNC_REPLY    = 27, /* Controller/switch message */
    OFPT_SET_ASYNC          = 28, /* Controller/switch message */

    /* Meters and rate limiters configuration messages. */
    OFPT_METER_MOD          = 29  /* Controller/switch message */
};


// 7.1.1  Padding

// 7.2  Common Structures

// 7.2.1  Port Structures

#define OFP_ETH_ALEN 6          /* Bytes in an Ethernet address. */
#define OFP_MAX_PORT_NAME_LEN  16

/* Description of a port */
struct ofp_port {
    uint32_t port_no;
    uint8_t pad[4];
    uint8_t hw_addr[OFP_ETH_ALEN];
    uint8_t pad2[2];                  /* Align to 64 bits. */
    char name[OFP_MAX_PORT_NAME_LEN]; /* Null-terminated */

    uint32_t config;        /* Bitmap of OFPPC_* flags. */
    uint32_t state;         /* Bitmap of OFPPS_* flags. */

    /* Bitmaps of OFPPF_* that describe features. All bits zeroed if
     * unsupported or unavailable. */
    uint32_t curr;          /* Current features. */
    uint32_t advertised;    /* Features being advertised by the port. */
    uint32_t supported;     /* Features supported by the port. */
    uint32_t peer;          /* Features advertised by peer. */

    uint32_t curr_speed;    /* Current port bitrate in kbps. */
    uint32_t max_speed;     /* Max port bitrate in kbps */
};
OFP_ASSERT(sizeof(struct ofp_port) == 64);

/* Flags to indicate behavior of the physical port. These flags are
 * used in ofp_port to describe the current configuration. They are
 * used in the ofp_port_mod message to configure the port's behavior.
 */
enum ofp_port_config {
    OFPPC_PORT_DOWN    = 1 << 0, /* Port is administratively down. */

    OFPPC_NO_RECV      = 1 << 2, /* Drop all packets received by port. */
    OFPPC_NO_FWD       = 1 << 5, /* Drop packets forwarded to port. */
    OFPPC_NO_PACKET_IN = 1 << 6  /* Do not send packet-in msgs for port. */
};

/* Current state of the physical port. These are not configurable from
 * the controller.
 */
enum ofp_port_state {
    OFPPS_LINK_DOWN = 1 << 0, /* No physical link present. */
    OFPPS_BLOCKED   = 1 << 1, /* Port is blocked */
    OFPPS_LIVE      = 1 << 2  /* Live for Fast Failover Group. */
};

/* Port numbering. Ports are numbered starting from 1. */
enum ofp_port_no {
    /* Maximum number of physical and logical switch ports. */
    OFPP_MAX        = 0xffffff00,

    /* Reserved OpenFlow Port (fake output "ports"). */
    OFPP_IN_PORT    = 0xfffffff8, /* Send the packet out the input port. This
                                     reserved port must be explicitly used
                                     in order to send back out of the input
                                     port. */
    OFPP_TABLE      = 0xfffffff9, /* Submit the packet to the first flow table
                                     NB: This destination port can only be
                                     used in packet-out messages. */
    OFPP_NORMAL     = 0xfffffffa, /* Process with normal L2/L3 switching. */
    OFPP_FLOOD      = 0xfffffffb, /* All physical ports in VLAN, except input
                                     port and those blocked or link down. */
    OFPP_ALL        = 0xfffffffc, /* All physical ports except input port. */
    OFPP_CONTROLLER = 0xfffffffd, /* Send to controller. */
    OFPP_LOCAL      = 0xfffffffe, /* Local openflow "port". */
    OFPP_ANY        = 0xffffffff  /* Wildcard port used only for flow mod
                                     (delete) and flow stats requests. Selects
                                     all flows regardless of output port
                                     (including flows with no output port). */
};

/* Features of ports available in a datapath. */
enum ofp_port_features {
    OFPPF_10MB_HD    = 1 << 0,  /* 10 Mb half-duplex rate support. */
    OFPPF_10MB_FD    = 1 << 1,  /* 10 Mb full-duplex rate support. */
    OFPPF_100MB_HD   = 1 << 2,  /* 100 Mb half-duplex rate support. */
    OFPPF_100MB_FD   = 1 << 3,  /* 100 Mb full-duplex rate support. */
    OFPPF_1GB_HD     = 1 << 4,  /* 1 Gb half-duplex rate support. */
    OFPPF_1GB_FD     = 1 << 5,  /* 1 Gb full-duplex rate support. */
    OFPPF_10GB_FD    = 1 << 6,  /* 10 Gb full-duplex rate support. */
    OFPPF_40GB_FD    = 1 << 7,  /* 40 Gb full-duplex rate support. */
    OFPPF_100GB_FD   = 1 << 8,  /* 100 Gb full-duplex rate support. */
    OFPPF_1TB_FD     = 1 << 9,  /* 1 Tb full-duplex rate support. */
    OFPPF_OTHER      = 1 << 10, /* Other rate, not in the list. */

    OFPPF_COPPER     = 1 << 11, /* Copper medium. */
    OFPPF_FIBER      = 1 << 12, /* Fiber medium. */
    OFPPF_AUTONEG    = 1 << 13, /* Auto-negotiation. */
    OFPPF_PAUSE      = 1 << 14, /* Pause. */
    OFPPF_PAUSE_ASYM = 1 << 15  /* Asymmetric pause. */
};


// 7.2.2  Queue Structures

/* Common description for a queue. */
struct ofp_queue_prop_header {
    uint16_t property;  /* One of OFPQT_. */
    uint16_t len;       /* Length of property, including this header. */
    uint8_t pad[4];     /* 64-bit alignemnt. */
};
OFP_ASSERT(sizeof(struct ofp_queue_prop_header) == 8);

/* Min-Rate queue property description. */
struct ofp_queue_prop_min_rate {
    struct ofp_queue_prop_header prop_header;   /* prop: OFPQT_MIN_RATE, len: 16. */
    uint16_t rate;      /* In 1/10 of a percent; >1000 -> disabled. */
    uint8_t pad[6];     /* 64-bit alignment */
};
OFP_ASSERT(sizeof(struct ofp_queue_prop_min_rate) == 16);

/* if minimum queue rate is not configured set to this */
#define OFPQ_MIN_RATE_UNCFG      0xffff

/* Max-Rate queue property description. */
struct ofp_queue_prop_max_rate {
    struct ofp_queue_prop_header prop_header;   /* prop: OFPQT_MAX_RATE, len: 16. */
    uint16_t rate;      /* In 1/10 of a percent; >1000 -> disabled. */
    uint8_t pad[6];     /* 64-bit alignment */
};
OFP_ASSERT(sizeof(struct ofp_queue_prop_max_rate) == 16);

/* if maximum queue rate is not configured set to this */
#define QFPQ_MAX_RATE_UNCFG      0xffff

/* Experimenter queue property description. */
struct ofp_queue_prop_experimenter {
    struct ofp_queue_prop_header prop_header; /* prop: OFPQT_EXPERIMENTER, len: 16. */
    uint32_t experimenter;  /* Experimenter ID which takes the same
                               form as in struct
                               ofp_experimenter_header. */
    uint8_t pad[4];         /* 64-bit alignment */
    uint8_t data[0];        /* Experimenter defined data. */
};
OFP_ASSERT(sizeof(struct ofp_queue_prop_experimenter) == 16);

/* Full description for a queue. */
struct ofp_packet_queue {
    uint32_t queue_id;  /* id for the specific queue. */
    uint32_t port;      /* Port this queue is attached to. */
    uint16_t len;       /* Length in bytes of this queue desc. */
    uint8_t pad[6];     /* 64-bit alignment. */
    struct ofp_queue_prop_header properties[0]; /* List of properties. */
};
OFP_ASSERT(sizeof(struct ofp_packet_queue) == 16);

enum ofp_queue_properties {
    OFPQT_MIN_RATE     = 1,     /* Minimum datarate guaranteed. */
    OFPQT_MAX_RATE     = 2,     /* Maximum datarate. */
    OFPQT_EXPERIMENTER = 0xffff /* Experimenter defined property. */
};


// 7.2.3  Flow Match Structures

// 7.2.3.1  Flow Match Header

/* Fields to match against flows */
struct ofp_match {
    uint16_t type;          /* One of OFPMT_* */
    uint16_t length;        /* Length of ofp_match (excluding padding) */
    /* Followed by:
     *  - Exactly (length - 4) (possibly 0) bytes containing OXM TLVs, then
     *  - Exactly ((length + 7)/8*8 - length) (between 0 and 7) bytes of
     *    all-zero bytes
     * In summary, ofp_match is padded as needed, to make its overall size
     * a multiple of 8, to preserve alignement in structures using it.
     */
    uint8_t oxm_fields[0];  /* 0 or more OXM match fields */
    uint8_t pad[4];         /* Zero bytes - see above for sizing */
};
OFP_ASSERT(sizeof(struct ofp_match) == 8);

/* The match type indicates the match structure (set of fields that compose the
 * match) in use. The match type is placed in the type field at the beginning
 * of all match structures. The "OpenFlow Extensible Match" type corresponds
 * to OXM TLV format described below and must be supported by all OpenFlow
 * switches. Extensions that define other match types may be published on the
 * ONF wiki. Support for extensions is optional.
 */
enum ofp_match_type {
    OFPMT_STANDARD = 0, /* Deprecated. */
    OFPMT_OXM      = 1  /* OpenFlow Extensible Match */
};


// 7.2.3.2  Flow Match Field Structures

// 7.2.3.3  OXM classes

/* OXM Class IDs.
 * The high order bit differentiate reserved classes from member classes.
 * Classes 0x0000 to 0x7FFF are member classes, allocated by ONF.
 * Classes 0x8000 to 0xFFFE are reserved classes, reserved for standardisation.
 */
enum ofp_oxm_class {
    OFPXMC_NXM_0          = 0x0000, /* Backward compatibility with NXM */
    OFPXMC_NXM_1          = 0x0001, /* Backward compatibility with NXM */
    OFPXMC_OPENFLOW_BASIC = 0x8000, /* Basic class for OpenFlow */
    OFPXMC_EXPERIMENTER   = 0xFFFF  /* Experimenter class */
};


// 7.2.3.4  Flow Matching

// 7.2.3.5  Flow Match Field Masking

// 7.2.3.6  Flow Match Field Prerequisite

// 7.2.3.7  Flow Match Fields

/* OXM Flow match field types for OpenFlow basic class. */
enum oxm_ofb_match_fields {
    OFPXMT_OFB_IN_PORT        = 0,  /* Switch input port. */
    OFPXMT_OFB_IN_PHY_PORT    = 1,  /* Switch physical input port. */
    OFPXMT_OFB_METADATA       = 2,  /* Metadata passed between tables. */
    OFPXMT_OFB_ETH_DST        = 3,  /* Ethernet destination address. */
    OFPXMT_OFB_ETH_SRC        = 4,  /* Ethernet source address. */
    OFPXMT_OFB_ETH_TYPE       = 5,  /* Ethernet frame type. */
    OFPXMT_OFB_VLAN_VID       = 6,  /* VLAN id. */
    OFPXMT_OFB_VLAN_PCP       = 7,  /* VLAN priority. */
    OFPXMT_OFB_IP_DSCP        = 8,  /* IP DSCP (6 bits in ToS field). */
    OFPXMT_OFB_IP_ECN         = 9,  /* IP ECN (2 bits in ToS field). */
    OFPXMT_OFB_IP_PROTO       = 10, /* IP protocol. */
    OFPXMT_OFB_IPV4_SRC       = 11, /* IPv4 source address. */
    OFPXMT_OFB_IPV4_DST       = 12, /* IPv4 destination address. */
    OFPXMT_OFB_TCP_SRC        = 13, /* TCP source port. */
    OFPXMT_OFB_TCP_DST        = 14, /* TCP destination port. */
    OFPXMT_OFB_UDP_SRC        = 15, /* UDP source port. */
    OFPXMT_OFB_UDP_DST        = 16, /* UDP destination port. */
    OFPXMT_OFB_SCTP_SRC       = 17, /* SCTP source port. */
    OFPXMT_OFB_SCTP_DST       = 18, /* SCTP destination port. */
    OFPXMT_OFB_ICMPV4_TYPE    = 19, /* ICMP type. */
    OFPXMT_OFB_ICMPV4_CODE    = 20, /* ICMP code. */
    OFPXMT_OFB_ARP_OP         = 21, /* ARP opcode. */
    OFPXMT_OFB_ARP_SPA        = 22, /* ARP source IPv4 address. */
    OFPXMT_OFB_ARP_TPA        = 23, /* ARP target IPv4 address. */
    OFPXMT_OFB_ARP_SHA        = 24, /* ARP source hardware address. */
    OFPXMT_OFB_ARP_THA        = 25, /* ARP target hardware address. */
    OFPXMT_OFB_IPV6_SRC       = 26, /* IPv6 source address. */
    OFPXMT_OFB_IPV6_DST       = 27, /* IPv6 destination address. */
    OFPXMT_OFB_IPV6_FLABEL    = 28, /* IPv6 Flow Label */
    OFPXMT_OFB_ICMPV6_TYPE    = 29, /* ICMPv6 type. */
    OFPXMT_OFB_ICMPV6_CODE    = 30, /* ICMPv6 code. */
    OFPXMT_OFB_IPV6_ND_TARGET = 31, /* Target address for ND. */
    OFPXMT_OFB_IPV6_ND_SLL    = 32, /* Source link-layer for ND. */
    OFPXMT_OFB_IPV6_ND_TLL    = 33, /* Target link-layer for ND. */
    OFPXMT_OFB_MPLS_LABEL     = 34, /* MPLS label. */
    OFPXMT_OFB_MPLS_TC        = 35, /* MPLS TC. */
    OFPXMT_OFB_MPLS_BOS       = 36, /* MPLS BoS bit. */
    OFPXMT_OFB_PBB_ISID       = 37, /* PBB I-SID. */
    OFPXMT_OFB_TUNNEL_ID      = 38, /* Logical Port Metadata. */
    OFPXMT_OFB_IPV6_EXTHDR    = 39  /* IPv6 Extension Header pseudo-field */
};

#define OFPXMT_OFB_ALL ((UINT64_C(1) << 40) - 1)

/* The VLAN id is 12-bits, so we can use the entire 16 bits to indicate
 * special conditions.
 */
enum ofp_vlan_id {
    OFPVID_PRESENT = 0x1000, /* Bit that indicate that a VLAN id is set */
    OFPVID_NONE    = 0x0000  /* No VLAN id was set. */
};

/* Define for compatibility */
#define OFP_VLAN_NONE OFPVID_NONE

/* Bit definitions for IPv6 Extension Header pseudo-field. */
enum ofp_ipv6exthdr_flags {
    OFPIEH_NONEXT = 1 << 0,     /* "No next header" encountered. */
    OFPIEH_ESP    = 1 << 1,     /* Encrypted Sec Payload header present. */
    OFPIEH_AUTH   = 1 << 2,     /* Authentication header present. */
    OFPIEH_DEST   = 1 << 3,     /* 1 or 2 dest headers present. */
    OFPIEH_FRAG   = 1 << 4,     /* Fragment header present. */
    OFPIEH_ROUTER = 1 << 5,     /* Router header present. */
    OFPIEH_HOP    = 1 << 6,     /* Hop-by-hop header present. */
    OFPIEH_UNREP  = 1 << 7,     /* Unexpected repeats encountered. */
    OFPIEH_UNSEQ  = 1 << 8      /* Unexpected sequencing encountered. */
};


// 7.2.3.8  Experimenter Flow Match Fields

/* Header for OXM experimenter match fields. */
struct ofp_oxm_experimenter_header {
    uint32_t oxm_header;    /* oxm_class = OFPXMC_EXPERIMENTER */
    uint32_t experimenter;  /* Experimenter ID which takes the same
                               form as in struct ofp_experimenter_header. */
};
OFP_ASSERT(sizeof(struct ofp_oxm_experimenter_header) == 8);


// 7.2.5  Action Structures

enum ofp_action_type {
    OFPAT_OUTPUT       = 0,  /* Output to switch port. */
    OFPAT_COPY_TTL_OUT = 11, /* Copy TTL "outwards" -- from next-to-outermost
                                to outermost */
    OFPAT_COPY_TTL_IN  = 12, /* Copy TTL "inwards" -- from outermost to
                                next-to-outermost */
    OFPAT_SET_MPLS_TTL = 15, /* MPLS TTL */
    OFPAT_DEC_MPLS_TTL = 16, /* Decrement MPLS TTL */

    OFPAT_PUSH_VLAN    = 17, /* Push a new VLAN tag */
    OFPAT_POP_VLAN     = 18, /* Pop the outer VLAN tag */
    OFPAT_PUSH_MPLS    = 19, /* Push a new MPLS tag */
    OFPAT_POP_MPLS     = 20, /* Pop the outer MPLS tag */
    OFPAT_SET_QUEUE    = 21, /* Set queue id when outputting to a port */
    OFPAT_GROUP        = 22, /* Apply group. */
    OFPAT_SET_NW_TTL   = 23, /* IP TTL. */
    OFPAT_DEC_NW_TTL   = 24, /* Decrement IP TTL. */
    OFPAT_SET_FIELD    = 25, /* Set a header field using OXM TLV format. */
    OFPAT_PUSH_PBB     = 26, /* Push a new PBB service tag (I-TAG) */
    OFPAT_POP_PBB      = 27, /* Pop the outer PBB service tag (I-TAG) */
    OFPAT_EXPERIMENTER = 0xffff
};

/* Action header that is common to all actions. The length includes the
 * header and any padding used to make the action 64-bit aligned.
 * NB: The length of an action *must* always be a multiple of eight. */
struct ofp_action_header {
    uint16_t type;          /* One of OFPAT_*. */
    uint16_t len;           /* Length of action, including this
                               header. This is the length of action,
                               including any padding to make it
                               64-bit aligned. */
    uint8_t pad[4];
};
OFP_ASSERT(sizeof(struct ofp_action_header) == 8);

/* Action structure for OFPAT_OUTPUT, which sends packets out 'port'.
 * When the 'port' is the OFPP_CONTROLLER, 'max_len' indicates the max
 * number of bytes to send. A 'max_len' of zero means no bytes of the
 * packet should be sent. A 'max_len' of OFPCML_NO_BUFFER means that
 * the packet is not buffered and the complete packet is to be sent to
 * the controller. */
struct ofp_action_output {
    uint16_t type;          /* OFPAT_OUTPUT. */
    uint16_t len;           /* Length is 16. */
    uint32_t port;          /* Output port. */
    uint16_t max_len;       /* Max length to send to controller. */
    uint8_t pad[6];         /* Pad to 64 bits. */
};
OFP_ASSERT(sizeof(struct ofp_action_output) == 16);

enum ofp_controller_max_len {
    OFPCML_MAX       = 0xffe5, /* maximum max_len value which can be used
                                  to request a specific byte length. */
    OFPCML_NO_BUFFER = 0xffff  /* indicates that no buffering should be
                                  applied and the whole packet is to be
                                  sent to the controller. */
};

/* Action structure for OFPAT_GROUP. */
struct ofp_action_group {
    uint16_t type;          /* OFPAT_GROUP. */
    uint16_t len;           /* Length is 8. */
    uint32_t group_id;      /* Group identifier. */
};
OFP_ASSERT(sizeof(struct ofp_action_group) == 8);

/* OFPAT_SET_QUEUE action struct: send packets to given queue on port. */
struct ofp_action_set_queue {
    uint16_t type;          /* OFPAT_SET_QUEUE. */
    uint16_t len;           /* Len is 8. */
    uint32_t queue_id;      /* Queue id for the packets. */
};
OFP_ASSERT(sizeof(struct ofp_action_set_queue) == 8);

/* Action structure for OFPAT_SET_MPLS_TTL. */
struct ofp_action_mpls_ttl {
    uint16_t type;          /* OFPAT_SET_MPLS_TTL. */
    uint16_t len;           /* Length is 8. */
    uint8_t mpls_ttl;       /* MPLS TTL */
    uint8_t pad[3];
};
OFP_ASSERT(sizeof(struct ofp_action_mpls_ttl) == 8);

/* Action structure for OFPAT_SET_NW_TTL. */
struct ofp_action_nw_ttl {
    uint16_t type;          /* OFPAT_SET_NW_TTL. */
    uint16_t len;           /* Length is 8. */
    uint8_t nw_ttl;         /* IP TTL */
    uint8_t pad[3];
};
OFP_ASSERT(sizeof(struct ofp_action_nw_ttl) == 8);

/* Action structure for OFPAT_PUSH_VLAN/MPLS/PBB. */
struct ofp_action_push {
    uint16_t type;          /* OFPAT_PUSH_VLAN/MPLS/PBB. */
    uint16_t len;           /* Length is 8. */
    uint16_t ethertype;     /* Ethertype */
    uint8_t pad[2];
};
OFP_ASSERT(sizeof(struct ofp_action_push) == 8);

/* Action structure for OFPAT_POP_MPLS. */
struct ofp_action_pop_mpls {
    uint16_t type;          /* OFPAT_POP_MPLS. */
    uint16_t len;           /* Length is 8. */
    uint16_t ethertype;     /* Ethertype */
    uint8_t pad[2];
};
OFP_ASSERT(sizeof(struct ofp_action_pop_mpls) == 8);

/* Action structure for OFPAT_SET_FIELD. */
struct ofp_action_set_field {
    uint16_t type;          /* OFPAT_SET_FIELD. */
    uint16_t len;           /* Length is padded to 64 bits. */
    /* Followed by:
     *  - Exactly (4 + oxm_length) bytes containing a single OXM TLV, then
     *  - Exactly ((8 + oxm_length) + 7)/8*8 - (8 + oxm_length)
     *    (between 0 and 7) bytes of all-zero bytes
     */
    uint8_t field[4];       /* OXM TLV - Make compiler happy */
};
OFP_ASSERT(sizeof(struct ofp_action_set_field) == 8);

/* Action header for OFPAT_EXPERIMENTER.
 * The rest of the body is experimenter-defined. */
struct ofp_action_experimenter_header {
    uint16_t type;          /* OFPAT_EXPERIMENTER. */
    uint16_t len;           /* Length is a multiple of 8. */
    uint32_t experimenter;  /* Experimenter ID which takes the same
                               form as in struct
                               ofp_experimenter_header. */
};
OFP_ASSERT(sizeof(struct ofp_action_experimenter_header) == 8);


// 7.2.4  Flow Instruction Structures

enum ofp_instruction_type {
    OFPIT_GOTO_TABLE     = 1, /* Setup the next table in the lookup
                                 pipeline */
    OFPIT_WRITE_METADATA = 2, /* Setup the metadata field for use later in
                                 pipeline */
    OFPIT_WRITE_ACTIONS  = 3, /* Write the action(s) onto the datapath action
                                 set */
    OFPIT_APPLY_ACTIONS  = 4, /* Applies the action(s) immediately */
    OFPIT_CLEAR_ACTIONS  = 5, /* Clears all actions from the datapath
                                 action set */
    OFPIT_METER          = 6, /* Apply meter (rate limiter) */

    OFPIT_EXPERIMENTER   = 0xFFFF /* Experimenter instruction */
};

/* Instruction header that is common to all instructions. The length includes
 * the header and any padding used to make the instruction 64-bit aligned.
 * NB: The length of an instruction *must* always be a multiple of eight. */
struct ofp_instruction {
    uint16_t type;         /* Instruction type */
    uint16_t len;          /* Length of this struct in bytes. */
};
OFP_ASSERT(sizeof(struct ofp_instruction) == 4);

/* Instruction structure for OFPIT_GOTO_TABLE */
struct ofp_instruction_goto_table {
    uint16_t type;          /* OFPIT_GOTO_TABLE */
    uint16_t len;           /* Length of this struct in bytes. */
    uint8_t table_id;       /* Set next table in the lookup pipeline */
    uint8_t pad[3];         /* Pad to 64 bits. */
};
OFP_ASSERT(sizeof(struct ofp_instruction_goto_table) == 8);

/* Instruction structure for OFPIT_WRITE_METADATA */
struct ofp_instruction_write_metadata {
    uint16_t type;          /* OFPIT_WRITE_METADATA */
    uint16_t len;           /* Length of this struct in bytes. */
    uint8_t pad[4];         /* Align to 64-bits */
    uint64_t metadata;      /* Metadata value to write */
    uint64_t metadata_mask; /* Metadata write bitmask */
};
OFP_ASSERT(sizeof(struct ofp_instruction_write_metadata) == 24);

/* Instruction structure for OFPIT_WRITE/APPLY/CLEAR_ACTIONS */
struct ofp_instruction_actions {
    uint16_t type;          /* One of OFPIT_*_ACTIONS */
    uint16_t len;           /* Length of this struct in bytes. */
    uint8_t pad[4];         /* Align to 64-bits */
    struct ofp_action_header actions[0];  /* Actions associated with
                                             OFPIT_WRITE_ACTIONS and
                                             OFPIT_APPLY_ACTIONS */
};
OFP_ASSERT(sizeof(struct ofp_instruction_actions) == 8);

/* Instruction structure for OFPIT_METER */
struct ofp_instruction_meter {
    uint16_t type;          /* OFPIT_METER */
    uint16_t len;           /* Length is 8. */
    uint32_t meter_id;      /* Meter instance. */
};
OFP_ASSERT(sizeof(struct ofp_instruction_meter) == 8);

/* Instruction structure for experimental instructions */
struct ofp_instruction_experimenter {
    uint16_t type;         /* OFPIT_EXPERIMENTER */
    uint16_t len;          /* Length of this struct in bytes */
    uint32_t experimenter; /* Experimenter ID which takes the same form
                              as in struct ofp_experimenter_header. */
    /* Experimenter-defined arbitrary additional data. */
};
OFP_ASSERT(sizeof(struct ofp_instruction_experimenter) == 8);


// 7.3  Controller-to-Switch Messages

// 7.3.1  Handshake

/* Switch features. */
struct ofp_switch_features {
    struct ofp_header header;
    uint64_t datapath_id;   /* Datapath unique ID. The lower 48-bits are for
                               a MAC address, while the upper 16-bits are
                               implementer-defined. */

    uint32_t n_buffers;     /* Max packets buffered at once. */

    uint8_t n_tables;       /* Number of tables supported by datapath. */
    uint8_t auxiliary_id;   /* Identify auxiliary connections */
    uint8_t pad[2];         /* Align to 64-bits. */

    /* Features. */
    uint32_t capabilities;  /* Bitmap of support "ofp_capabilities". */
    uint32_t reserved;
};
OFP_ASSERT(sizeof(struct ofp_switch_features) == 32);

/* Capabilities supported by the datapath. */
enum ofp_capabilities {
    OFPC_FLOW_STATS   = 1 << 0, /* Flow statistics. */
    OFPC_TABLE_STATS  = 1 << 1, /* Table statistics. */
    OFPC_PORT_STATS   = 1 << 2, /* Port statistics. */
    OFPC_GROUP_STATS  = 1 << 3, /* Group statistics. */
    OFPC_IP_REASM     = 1 << 5, /* Can reassemble IP fragments. */
    OFPC_QUEUE_STATS  = 1 << 6, /* Queue statistics. */
    OFPC_PORT_BLOCKED = 1 << 8  /* Switch will block looping ports. */
};


// 7.3.2  Switch Configuration

/* Switch configuration. */
struct ofp_switch_config {
    struct ofp_header header;
    uint16_t flags;             /* Bitmap of OFPC_FRAG_* flags. */
    uint16_t miss_send_len;     /* Max bytes of packet that datapath
                                   should send to the controller. See
                                   ofp_controller_max_len for valid values.
                                   */
};
OFP_ASSERT(sizeof(struct ofp_switch_config) == 12);

enum ofp_config_flags {
    /* Handling of IP fragments. */
    OFPC_FRAG_NORMAL = 0,      /* No special handling for fragments. */
    OFPC_FRAG_DROP   = 1 << 0, /* Drop fragments. */
    OFPC_FRAG_REASM  = 1 << 1, /* Reassemble (only if OFPC_IP_REASM set). */
    OFPC_FRAG_MASK   = 3
};

#define OFP_DEFAULT_MISS_SEND_LEN 128


// 7.3.3  Flow Table Configuration

/* Table numbering. Tables can use any number up to OFPTT_MAX. */
enum ofp_table {
    /* Last usable table number. */
    OFPTT_MAX = 0xfe,

    /* Fake tables. */
    OFPTT_ALL = 0xff    /* Wildcard table used for table config,
                           flow stats and flow deletes. */
};

/* Configure/Modify behavior of a flow table */
struct ofp_table_mod {
    struct ofp_header header;
    uint8_t table_id;   /* ID of the table, OFPTT_ALL indicates all tables */
    uint8_t pad[3];     /* Pad to 32 bits */
    uint32_t config;    /* Bitmap of OFPTC_* flags */
};
OFP_ASSERT(sizeof(struct ofp_table_mod) == 16);

/* Flags to configure the table. Reserved for future use. */
enum ofp_table_config {
    OFPTC_DEPRECATED_MASK = 3, /* Deprecated bits */
};


// 7.3.4  Modify State Messages

// 7.3.4.1  Modify Flow Entry Message

/* Flow setup and teardown (controller -> datapath). */
struct ofp_flow_mod {
    struct ofp_header header;
    uint64_t cookie;        /* Opaque controller-issued identifier. */
    uint64_t cookie_mask;   /* Mask used to restrict the cookie bits
                               that must match when the command is
                               OFPFC_MODIFY* or OFPFC_DELETE*. A value
                               of 0 indicates no restriction. */

    /* Flow actions. */
    uint8_t table_id;       /* ID of the table to put the flow in.
                               For OFPFC_DELETE_* commands, OFPTT_ALL
                               can also be used to delete matching
                               flows from all tables. */
    uint8_t command;        /* One of OFPFC_*. */
    uint16_t idle_timeout;  /* Idle time before discarding (seconds). */
    uint16_t hard_timeout;  /* Max time before discarding (seconds). */
    uint16_t priority;      /* Priority level of flow entry. */
    uint32_t buffer_id;     /* Buffered packet to apply to, or
                               OFP_NO_BUFFER.
                               Not meaningful for OFPFC_DELETE*. */
    uint32_t out_port;      /* For OFPFC_DELETE* commands, require
                               matching entries to include this as an
                               output port. A value of OFPP_ANY
                               indicates no restriction. */
    uint32_t out_group;     /* For OFPFC_DELETE* commands, require
                               matching entries to include this as an
                               output group. A value of OFPG_ANY
                               indicates no restriction. */
    uint16_t flags;         /* Bitmap of OFPFF_* flags. */
    uint8_t pad[2];
    struct ofp_match match; /* Fields to match. Variable size. */
    /* The variable size and padded match is always followed by instructions. */
    /* struct ofp_instruction instructions[0]; */ /* Instruction set - 0 or more.
                                                     The length of the instruction
                                                     set is inferred from the
                                                     length field in the header. */
};
OFP_ASSERT(sizeof(struct ofp_flow_mod) == 56);

/* By default, choose a priority in the middle. */
#define OFP_DEFAULT_PRIORITY 0x8000
#define OFP_HIGH_PRIORITY    0xffff
#define OFP_LOW_PRIORITY     0x0000

enum ofp_flow_mod_command {
    OFPFC_ADD           = 0, /* New flow. */
    OFPFC_MODIFY        = 1, /* Modify all matching flows. */
    OFPFC_MODIFY_STRICT = 2, /* Modify entry strictly matching wildcards and
                                priority. */
    OFPFC_DELETE        = 3, /* Delete all matching flows. */
    OFPFC_DELETE_STRICT = 4  /* Delete entry strictly matching wildcards and
                                priority. */
};

enum ofp_flow_mod_flags {
    OFPFF_SEND_FLOW_REM = 1 << 0, /* Send flow removed message when flow
                                     expires or is deleted. */
    OFPFF_CHECK_OVERLAP = 1 << 1, /* Check for overlapping entries first. */
    OFPFF_RESET_COUNTS  = 1 << 2, /* Reset flow packet and byte counts. */
    OFPFF_NO_PKT_COUNTS = 1 << 3, /* Don't keep track of packet count. */
    OFPFF_NO_BYT_COUNTS = 1 << 4  /* Don't keep track of byte count. */
};


// 7.3.4.2  Modify Group Entry Message

/* Bucket for use in groups. */
struct ofp_bucket {
    uint16_t len;           /* Length the bucket in bytes, including
                               this header and any padding to make it
                               64-bit aligned. */
    uint16_t weight;        /* Relative weight of bucket. Only
                               defined for select groups. */
    uint32_t watch_port;    /* Port whose state affects whether this
                               bucket is live. Only required for fast
                               failover groups. */
    uint32_t watch_group;   /* Group whose state affects whether this
                               bucket is live. Only required for fast
                               failover groups. */
    uint8_t pad[4];
    struct ofp_action_header actions[0]; /* 0 or more actions associated with
                                            the bucket - The action list length
                                            is inferred from the length
                                            of the bucket. */
};
OFP_ASSERT(sizeof(struct ofp_bucket) == 16);

/* Group setup and teardown (controller -> datapath). */
struct ofp_group_mod {
    struct ofp_header header;
    uint16_t command;             /* One of OFPGC_*. */
    uint8_t type;                 /* One of OFPGT_*. */
    uint8_t pad;                  /* Pad to 64 bits. */
    uint32_t group_id;            /* Group identifier. */
    struct ofp_bucket buckets[0]; /* The length of the bucket array is inferred
                                     from the length field in the header. */
};
OFP_ASSERT(sizeof(struct ofp_group_mod) == 16);

/* Group commands */
enum ofp_group_mod_command {
    OFPGC_ADD    = 0,   /* New group. */
    OFPGC_MODIFY = 1,   /* Modify all matching groups. */
    OFPGC_DELETE = 2    /* Delete all matching groups. */
};

/* Group types. Values in the range [128, 255] are reserved for experimental
 * use. */
enum ofp_group_type {
    OFPGT_ALL      = 0, /* All (multicast/broadcast) group. */
    OFPGT_SELECT   = 1, /* Select group. */
    OFPGT_INDIRECT = 2, /* Indirect group. */
    OFPGT_FF       = 3  /* Fast failover group. */
};

/* Group numbering. Groups can use any number up to OFPG_MAX. */
enum ofp_group {
    /* Last usable group number. */
    OFPG_MAX = 0xffffff00,

    /* Fake groups. */
    OFPG_ALL = 0xfffffffc, /* Represents all groups for group delete
                              commands. */
    OFPG_ANY = 0xffffffff  /* Wildcard group used only for flow stats
                              requests. Selects all flows regardless of
                              group (including flows with no group).
                              */
};


// 7.3.4.3  Port Modification Message

/* Modify behavior of the physical port */
struct ofp_port_mod {
    struct ofp_header header;
    uint32_t port_no;
    uint8_t pad[4];
    uint8_t hw_addr[OFP_ETH_ALEN]; /* The hardware address is not
                                      configurable. This is used to
                                      sanity-check the request, so it must
                                      be the same as returned in an
                                      ofp_port struct. */
    uint8_t pad2[2];        /* Pad to 64 bits. */
    uint32_t config;        /* Bitmap of OFPPC_* flags. */
    uint32_t mask;          /* Bitmap of OFPPC_* flags to be changed. */

    uint32_t advertise;     /* Bitmap of OFPPF_*. Zero all bits to prevent
                               any action taking place. */
    uint8_t pad3[4];        /* Pad to 64 bits. */
};
OFP_ASSERT(sizeof(struct ofp_port_mod) == 40);


// 7.3.4.4  Meter Modification Message

/* Common header for all meter bands */
struct ofp_meter_band_header {
    uint16_t type;          /* One of OFPMBT_*. */
    uint16_t len;           /* Length in bytes of this band. */
    uint32_t rate;          /* Rate for this band. */
    uint32_t burst_size;    /* Size of bursts. */
};
OFP_ASSERT(sizeof(struct ofp_meter_band_header) == 12);

/* Meter configuration. OFPT_METER_MOD. */
struct ofp_meter_mod {
    struct ofp_header header;
    uint16_t command;       /* One of OFPMC_*. */
    uint16_t flags;         /* Bitmap of OFPMF_* flags. */
    uint32_t meter_id;      /* Meter instance. */
    struct ofp_meter_band_header bands[0]; /* The bands length is
                                              inferred from the length field
                                              in the header. */
};
OFP_ASSERT(sizeof(struct ofp_meter_mod) == 16);

/* Meter numbering. Flow meters can use any number up to OFPM_MAX. */
enum ofp_meter {
    /* Last usable meter. */
    OFPM_MAX        = 0xffff0000,

    /* Virtual meters. */
    OFPM_SLOWPATH   = 0xfffffffd, /* Meter for slow datapath, if any. */
    OFPM_CONTROLLER = 0xfffffffe, /* Meter for controller connection. */
    OFPM_ALL        = 0xffffffff  /* Represents all meters for stat requests
                                     commands. */
};

/* Meter commands */
enum ofp_meter_mod_command {
    OFPMC_ADD    = 0,       /* New meter. */
    OFPMC_MODIFY = 1,       /* Modify specified meter. */
    OFPMC_DELETE = 2        /* Delete specified meter. */
};

/* Meter configuration flags */
enum ofp_meter_flags {
    OFPMF_KBPS  = 1 << 0, /* Rate value in kb/s (kilo-bit per second). */
    OFPMF_PKTPS = 1 << 1, /* Rate value in packet/sec. */
    OFPMF_BURST = 1 << 2, /* Do burst size. */
    OFPMF_STATS = 1 << 3  /* Collect statistics. */
};

/* Meter band types */
enum ofp_meter_band_type {
    OFPMBT_DROP         = 1,     /* Drop packet. */
    OFPMBT_DSCP_REMARK  = 2,     /* Remark DSCP in the IP header. */
    OFPMBT_EXPERIMENTER = 0xFFFF /* Experimenter meter band. */
};

/* OFPMBT_DROP band - drop packets */
struct ofp_meter_band_drop {
    uint16_t type;          /* OFPMBT_DROP. */
    uint16_t len;           /* Length in bytes of this band. */
    uint32_t rate;          /* Rate for dropping packets. */
    uint32_t burst_size;    /* Size of bursts. */
    uint8_t pad[4];
};
OFP_ASSERT(sizeof(struct ofp_meter_band_drop) == 16);

/* OFPMBT_DSCP_REMARK band - Remark DSCP in the IP header */
struct ofp_meter_band_dscp_remark {
    uint16_t type;          /* OFPMBT_DSCP_REMARK. */
    uint16_t len;           /* Length in bytes of this band. */
    uint32_t rate;          /* Rate for remarking packets. */
    uint32_t burst_size;    /* Size of bursts. */
    uint8_t prec_level;     /* Number of precendence level to substract. */
    uint8_t pad[3];
};
OFP_ASSERT(sizeof(struct ofp_meter_band_dscp_remark) == 16);

/* OFPMBT_EXPERIMENTER band - Write actions in action set */
struct ofp_meter_band_experimenter {
    uint16_t type;          /* One of OFPMBT_*. */
    uint16_t len;           /* Length in bytes of this band. */
    uint32_t rate;          /* Rate for this band. */
    uint32_t burst_size;    /* Size of bursts. */
    uint32_t experimenter;  /* Experimenter ID which takes the same
                               form as in struct
                               ofp_experimenter_header. */
};
OFP_ASSERT(sizeof(struct ofp_meter_band_experimenter) == 16);


// 7.3.5  Multipart Messages

struct ofp_multipart_request {
    struct ofp_header header;
    uint16_t type;          /* One of the OFPMP_* constants. */
    uint16_t flags;         /* OFPMPF_REQ_* flags. */
    uint8_t pad[4];
    uint8_t body[0];        /* Body of the request. 0 or more bytes. */
};
OFP_ASSERT(sizeof(struct ofp_multipart_request) == 16);

enum ofp_multipart_request_flags {
    OFPMPF_REQ_MORE = 1 << 0 /* More requests to follow. */
};

struct ofp_multipart_reply {
    struct ofp_header header;
    uint16_t type;          /* One of the OFPMP_* constants. */
    uint16_t flags;         /* OFPMPF_REPLY_* flags. */
    uint8_t pad[4];
    uint8_t body[0];        /* Body of the reply. 0 or more bytes. */
};
OFP_ASSERT(sizeof(struct ofp_multipart_reply) == 16);

enum ofp_multipart_reply_flags {
    OFPMPF_REPLY_MORE = 1 << 0 /* More replies to follow. */
};

enum ofp_multipart_types {
    /* Description of this OpenFlow switch.
     * The request body is empty.
     * The reply body is struct ofp_desc. */
    OFPMP_DESC = 0,

    /* Individual flow statistics.
     * The request body is struct ofp_flow_stats_request.
     * The reply body is an array of struct ofp_flow_stats. */
    OFPMP_FLOW = 1,

    /* Aggregate flow statistics.
     * The request body is struct ofp_aggregate_stats_request.
     * The reply body is struct ofp_aggregate_stats_reply. */
    OFPMP_AGGREGATE = 2,

    /* Flow table statistics.
     * The request body is empty.
     * The reply body is an array of struct ofp_table_stats. */
    OFPMP_TABLE = 3,

    /* Port statistics.
     * The request body is struct ofp_port_stats_request.
     * The reply body is an array of struct ofp_port_stats. */
    OFPMP_PORT_STATS = 4,

    /* Queue statistics for a port
     * The request body is struct ofp_queue_stats_request.
     * The reply body is an array of struct ofp_queue_stats */
    OFPMP_QUEUE = 5,

    /* Group counter statistics.
     * The request body is struct ofp_group_stats_request.
     * The reply is an array of struct ofp_group_stats. */
    OFPMP_GROUP = 6,

    /* Group description.
     * The request body is empty.
     * The reply body is an array of struct ofp_group_desc. */
    OFPMP_GROUP_DESC = 7,

    /* Group features.
     * The request body is empty.
     * The reply body is struct ofp_group_features. */
    OFPMP_GROUP_FEATURES = 8,

    /* Meter statistics.
     * The request body is struct ofp_meter_multipart_requests.
     * The reply body is an array of struct ofp_meter_stats. */
    OFPMP_METER = 9,

    /* Meter configuration.
     * The request body is struct ofp_meter_multipart_requests.
     * The reply body is an array of struct ofp_meter_config. */
    OFPMP_METER_CONFIG = 10,

    /* Meter features.
     * The request body is empty.
     * The reply body is struct ofp_meter_features. */
    OFPMP_METER_FEATURES = 11,

    /* Table features.
     * The request body is either empty or contains an array of
     * struct ofp_table_features containing the controller's
     * desired view of the switch. If the switch is unable to
     * set the specified view an error is returned.
     * The reply body is an array of struct ofp_table_features. */
    OFPMP_TABLE_FEATURES = 12,

    /* Port description.
     * The request body is empty.
     * The reply body is an array of struct ofp_port. */
    OFPMP_PORT_DESC = 13,

    /* Experimenter extension.
     * The request and reply bodies begin with
     * struct ofp_experimenter_multipart_header.
     * The request and reply bodies are otherwise experimenter-defined. */
    OFPMP_EXPERIMENTER = 0xffff
};


// 7.3.5.1  Description

#define DESC_STR_LEN   256
#define SERIAL_NUM_LEN 32

/* Body of reply to OFPMP_DESC request. Each entry is a NULL-terminated
 * ASCII string. */
struct ofp_desc {
    char mfr_desc[DESC_STR_LEN];        /* Manufacturer description. */
    char hw_desc[DESC_STR_LEN];         /* Hardware description. */
    char sw_desc[DESC_STR_LEN];         /* Software description. */
    char serial_num[SERIAL_NUM_LEN];    /* Serial number. */
    char dp_desc[DESC_STR_LEN];         /* Human readable description of datapath. */
};
OFP_ASSERT(sizeof(struct ofp_desc) == 1056);


// 7.3.5.2  Individual Flow Statistics

/* Body for ofp_multipart_request of type OFPMP_FLOW. */
struct ofp_flow_stats_request {
    uint8_t table_id;       /* ID of table to read (from ofp_table_stats),
                               OFPTT_ALL for all tables. */
    uint8_t pad[3];         /* Align to 32 bits. */
    uint32_t out_port;      /* Require matching entries to include this
                               as an output port. A value of OFPP_ANY
                               indicates no restriction. */
    uint32_t out_group;     /* Require matching entries to include this
                               as an output group. A value of OFPG_ANY
                               indicates no restriction. */
    uint8_t pad2[4];        /* Align to 64 bits. */
    uint64_t cookie;        /* Require matching entries to contain this
                               cookie value */
    uint64_t cookie_mask;   /* Mask used to restrict the cookie bits that
                               must match. A value of 0 indicates
                               no restriction. */
    struct ofp_match match; /* Fields to match. Variable size. */
};
OFP_ASSERT(sizeof(struct ofp_flow_stats_request) == 40);

/* Body of reply to OFPMP_FLOW request. */
struct ofp_flow_stats {
    uint16_t length;        /* Length of this entry. */
    uint8_t table_id;       /* ID of table flow came from. */
    uint8_t pad;
    uint32_t duration_sec;  /* Time flow has been alive in seconds. */
    uint32_t duration_nsec; /* Time flow has been alive in nanoseconds beyond
                               duration_sec. */
    uint16_t priority;      /* Priority of the entry. */
    uint16_t idle_timeout;  /* Number of seconds idle before expiration. */
    uint16_t hard_timeout;  /* Number of seconds before expiration. */
    uint16_t flags;         /* Bitmap of OFPFF_* flags. */
    uint8_t pad2[4];        /* Align to 64-bits. */
    uint64_t cookie;        /* Opaque controller-issued identifier. */
    uint64_t packet_count;  /* Number of packets in flow. */
    uint64_t byte_count;    /* Number of bytes in flow. */
    struct ofp_match match; /* Description of fields. Variable size. */
    /* The variable size and padded match is always followed by instructions. */
    //struct ofp_instruction instructions[0]; /* Instruction set - 0 or more. */
};
OFP_ASSERT(sizeof(struct ofp_flow_stats) == 56);


// 7.3.5.3  Aggregate Flow Statistics

/* Body for ofp_multipart_request of type OFPMP_AGGREGATE. */
struct ofp_aggregate_stats_request {
    uint8_t table_id;       /* ID of table to read (from ofp_table_stats)
                               OFPTT_ALL for all tables. */
    uint8_t pad[3];         /* Align to 32 bits. */
    uint32_t out_port;      /* Require matching entries to include this
                               as an output port. A value of OFPP_ANY
                               indicates no restriction. */
    uint32_t out_group;     /* Require matching entries to include this
                               as an output group. A value of OFPG_ANY
                               indicates no restriction. */
    uint8_t pad2[4];        /* Align to 64 bits. */
    uint64_t cookie;        /* Require matching entries to contain this
                               cookie value */
    uint64_t cookie_mask;   /* Mask used to restrict the cookie bits that
                               must match. A value of 0 indicates
                               no restriction. */
    struct ofp_match match; /* Fields to match. Variable size. */
};
OFP_ASSERT(sizeof(struct ofp_aggregate_stats_request) == 40);

/* Body of reply to OFPMP_AGGREGATE request. */
struct ofp_aggregate_stats_reply {
    uint64_t packet_count;  /* Number of packets in flows. */
    uint64_t byte_count;    /* Number of bytes in flows. */
    uint32_t flow_count;    /* Number of flows. */
    uint8_t pad[4];         /* Align to 64 bits. */
};
OFP_ASSERT(sizeof(struct ofp_aggregate_stats_reply) == 24);


// 7.3.5.4  Table Statistics

/* Body of reply to OFPMP_TABLE request. */
struct ofp_table_stats {
    uint8_t table_id;       /* Identifier of table. Lower numbered tables
                               are consulted first. */
    uint8_t pad[3];         /* Align to 32-bits. */
    uint32_t active_count;  /* Number of active entries. */
    uint64_t lookup_count;  /* Number of packets looked up in table. */
    uint64_t matched_count; /* Number of packets that hit table. */
};
OFP_ASSERT(sizeof(struct ofp_table_stats) == 24);


// 7.3.5.5 Table Features

#define OFP_MAX_TABLE_NAME_LEN 32

/* Common header for all Table Feature Properties */
struct ofp_table_feature_prop_header {
    uint16_t type;         /* One of OFPTFPT_*. */
    uint16_t length;       /* Length in bytes of this property. */
};
OFP_ASSERT(sizeof(struct ofp_table_feature_prop_header) == 4);

/* Instructions property */
struct ofp_table_feature_prop_instructions {
    uint16_t type;              /* One of OFPTFPT_INSTRUCTIONS,
                                   OFPTFPT_INSTRUCTIONS_MISS. */
    uint16_t length;            /* Length in bytes of this property. */
    /* Followed by:
     *  - Exactly (length - 4) bytes containing the instruction ids, then
     *  - Exactly (length + 7)/8*8 - (length) (between 0 and 7)
     *    bytes of all-zero bytes */
    struct ofp_instruction instruction_ids[0]; /* List of instructions */
};
OFP_ASSERT(sizeof(struct ofp_table_feature_prop_instructions) == 4);

/* Next Tables property */
struct ofp_table_feature_prop_next_tables {
    uint16_t type;              /* One of OFPTFPT_NEXT_TABLES,
                                   OFPTFPT_NEXT_TABLES_MISS. */
    uint16_t length;            /* Length in bytes of this property. */
    /* Followed by:
     *  - Exactly (length - 4) bytes containing the table_ids, then
     *  - Exactly (length + 7)/8*8 - (length) (between 0 and 7)
     *    bytes of all-zero bytes */
    uint8_t next_table_ids[0]; /* List of table ids. */
};
OFP_ASSERT(sizeof(struct ofp_table_feature_prop_next_tables) == 4);

/* Actions property */
struct ofp_table_feature_prop_actions {
    uint16_t type;              /* One of OFPTFPT_WRITE_ACTIONS,
                                   OFPTFPT_WRITE_ACTIONS_MISS,
                                   OFPTFPT_APPLY_ACTIONS,
                                   OFPTFPT_APPLY_ACTIONS_MISS. */
    uint16_t length;            /* Length in bytes of this property. */
    /* Followed by:
     *  - Exactly (length - 4) bytes containing the action_ids, then
     *  - Exactly (length + 7)/8*8 - (length) (between 0 and 7)
     *    bytes of all-zero bytes */
    struct ofp_action_header action_ids[0]; /* List of actions */
};
OFP_ASSERT(sizeof(struct ofp_table_feature_prop_actions) == 4);

/* Match, Wildcard or Set-Field property */
struct ofp_table_feature_prop_oxm {
    uint16_t type;              /* One of OFPTFPT_MATCH,
                                   OFPTFPT_WILDCARDS,
                                   OFPTFPT_WRITE_SETFIELD,
                                   OFPTFPT_WRITE_SETFIELD_MISS,
                                   OFPTFPT_APPLY_SETFIELD,
                                   OFPTFPT_APPLY_SETFIELD_MISS. */
    uint16_t length;            /* Length in bytes of this property. */
    /* Followed by:
     *  - Exactly (length - 4) bytes containing the oxm_ids, then
     *  - Exactly (length + 7)/8*8 - (length) (between 0 and 7)
     *    bytes of all-zero bytes */
    uint32_t oxm_ids[0]; /* Array of OXM headers */
};
OFP_ASSERT(sizeof(struct ofp_table_feature_prop_oxm) == 4);

/* Experimenter table feature property */
struct ofp_table_feature_prop_experimenter {
    uint16_t type;         /* One of OFPTFPT_EXPERIMENTER,
                              OFPTFPT_EXPERIMENTER_MISS. */
    uint16_t length;       /* Length in bytes of this property. */
    uint32_t experimenter; /* Experimenter ID which takes the same
                              form as in struct
                              ofp_experimenter_header. */
    uint32_t exp_type;     /* Experimenter defined. */
    /* Followed by:
     *  - Exactly (length - 12) bytes containing the experimenter data, then
     *  - Exactly (length + 7)/8*8 - (length) (between 0 and 7)
     *    bytes of all-zero bytes */
    uint32_t experimenter_data[0];
};
OFP_ASSERT(sizeof(struct ofp_table_feature_prop_experimenter) == 12);

/* Body for ofp_multipart_request of type OFPMP_TABLE_FEATURES./
 * Body of reply to OFPMP_TABLE_FEATURES request. */
struct ofp_table_features {
    uint16_t length;            /* Length is padded to 64 bits. */
    uint8_t table_id;           /* Identifier of table. Lower numbered tables
                                   are consulted first. */
    uint8_t pad[5];             /* Align to 64-bits. */
    char name[OFP_MAX_TABLE_NAME_LEN];
    uint64_t metadata_match;    /* Bits of metadata table can match. */
    uint64_t metadata_write;    /* Bits of metadata table can write. */
    uint32_t config;            /* Bitmap of OFPTC_* values */
    uint32_t max_entries;       /* Max number of entries supported. */

    /* Table Feature Property list */
    struct ofp_table_feature_prop_header properties[0]; /* List of properties */
};
OFP_ASSERT(sizeof(struct ofp_table_features) == 64);

/* Table Feature property types.
 * Low order bit cleared indicates a property for a regular Flow Entry.
 * Low order bit set indicates a property for the Table-Miss Flow Entry.
 */
enum ofp_table_feature_prop_type {
    OFPTFPT_INSTRUCTIONS        = 0,  /* Instructions property. */
    OFPTFPT_INSTRUCTIONS_MISS   = 1,  /* Instructions for table-miss. */
    OFPTFPT_NEXT_TABLES         = 2,  /* Next Table property. */
    OFPTFPT_NEXT_TABLES_MISS    = 3,  /* Next Table for table-miss. */
    OFPTFPT_WRITE_ACTIONS       = 4,  /* Write Actions property. */
    OFPTFPT_WRITE_ACTIONS_MISS  = 5,  /* Write Actions for table-miss. */
    OFPTFPT_APPLY_ACTIONS       = 6,  /* Apply Actions property. */
    OFPTFPT_APPLY_ACTIONS_MISS  = 7,  /* Apply Actions for table-miss. */
    OFPTFPT_MATCH               = 8,  /* Match property. */
    OFPTFPT_WILDCARDS           = 10, /* Wildcards property. */
    OFPTFPT_WRITE_SETFIELD      = 12, /* Write Set-Field property. */
    OFPTFPT_WRITE_SETFIELD_MISS = 13, /* Write Set-Field for table-miss. */
    OFPTFPT_APPLY_SETFIELD      = 14, /* Apply Set-Field property. */
    OFPTFPT_APPLY_SETFIELD_MISS = 15, /* Apply Set-Field for table-miss. */
    OFPTFPT_EXPERIMENTER        = 0xFFFE, /* Experimenter property. */
    OFPTFPT_EXPERIMENTER_MISS   = 0xFFFF  /* Experimenter for table-miss. */
};


// 7.3.5.6  Port Statistics

/* Body for ofp_multipart_request of type OFPMP_PORT. */
struct ofp_port_stats_request {
    uint32_t port_no;   /* OFPMP_PORT message must request statistics
                           either for a single port (specified in
                           port_no) or for all ports (if port_no ==
                           OFPP_ANY). */
    uint8_t pad[4];
};
OFP_ASSERT(sizeof(struct ofp_port_stats_request) == 8);

/* Body of reply to OFPMP_PORT request. If a counter is unsupported, set
 * the field to all ones. */
struct ofp_port_stats {
    uint32_t port_no;
    uint8_t pad[4];         /* Align to 64-bits. */
    uint64_t rx_packets;    /* Number of received packets. */
    uint64_t tx_packets;    /* Number of transmitted packets. */
    uint64_t rx_bytes;      /* Number of received bytes. */
    uint64_t tx_bytes;      /* Number of transmitted bytes. */
    uint64_t rx_dropped;    /* Number of packets dropped by RX. */
    uint64_t tx_dropped;    /* Number of packets dropped by TX. */
    uint64_t rx_errors;     /* Number of receive errors. This is a super-set
                               of more specific receive errors and should be
                               greater than or equal to the sum of all
                               rx_*_err values. */
    uint64_t tx_errors;     /* Number of transmit errors. This is a super-set
                               of more specific transmit errors and should be
                               greater than or equal to the sum of all
                               tx_*_err values (none currently defined.) */
    uint64_t rx_frame_err;  /* Number of frame alignment errors. */
    uint64_t rx_over_err;   /* Number of packets with RX overrun. */
    uint64_t rx_crc_err;    /* Number of CRC errors. */
    uint64_t collisions;    /* Number of collisions. */
    uint32_t duration_sec;  /* Time port has been alive in seconds. */
    uint32_t duration_nsec; /* Time port has been alive in nanoseconds beyond
                               duration_sec. */
};
OFP_ASSERT(sizeof(struct ofp_port_stats) == 112);


// 7.3.5.7  Port Description

// 7.3.5.8  Queue Statistics

/* All ones is used to indicate all queues in a port (for stats retrieval). */
#define OFPQ_ALL 0xffffffff

struct ofp_queue_stats_request {
    uint32_t port_no;       /* All ports if OFPP_ANY. */
    uint32_t queue_id;      /* All queues if OFPQ_ALL. */
};
OFP_ASSERT(sizeof(struct ofp_queue_stats_request) == 8);

struct ofp_queue_stats {
    uint32_t port_no;
    uint32_t queue_id;      /* Queue i.d */
    uint64_t tx_bytes;      /* Number of transmitted bytes. */
    uint64_t tx_packets;    /* Number of transmitted packets. */
    uint64_t tx_errors;     /* Number of packets dropped due to overrun. */
    uint32_t duration_sec;  /* Time queue has been alive in seconds. */
    uint32_t duration_nsec; /* Time queue has been alive in nanoseconds beyond
                               duration_sec. */
};
OFP_ASSERT(sizeof(struct ofp_queue_stats) == 40);


// 7.3.5.9  Group Statistics

/* Body of OFPMP_GROUP request. */
struct ofp_group_stats_request {
    uint32_t group_id;      /* All groups if OFPG_ALL. */
    uint8_t pad[4];         /* Align to 64 bits. */
};
OFP_ASSERT(sizeof(struct ofp_group_stats_request) == 8);

/* Used in group stats replies. */
struct ofp_bucket_counter {
    uint64_t packet_count;  /* Number of packets processed by bucket. */
    uint64_t byte_count;    /* Number of bytes processed by bucket. */
};
OFP_ASSERT(sizeof(struct ofp_bucket_counter) == 16);

/* Body of reply to OFPMP_GROUP request. */
struct ofp_group_stats {
    uint16_t length;        /* Length of this entry. */
    uint8_t pad[2];         /* Align to 64 bits. */
    uint32_t group_id;      /* Group identifier. */
    uint32_t ref_count;     /* Number of flows or groups that directly forward
                               to this group. */
    uint8_t pad2[4];        /* Align to 64 bits. */
    uint64_t packet_count;  /* Number of packets processed by group. */
    uint64_t byte_count;    /* Number of bytes processed by group. */
    uint32_t duration_sec;  /* Time group has been alive in seconds. */
    uint32_t duration_nsec; /* Time group has been alive in nanoseconds beyond
                               duration_sec. */
    struct ofp_bucket_counter bucket_stats[0]; /* One counter set per bucket. */
};
OFP_ASSERT(sizeof(struct ofp_group_stats) == 40);


// 7.3.5.10 Group Description

/* Body of reply to OFPMP_GROUP_DESC request. */
struct ofp_group_desc {
    uint16_t length;        /* Length of this entry. */
    uint8_t type;           /* One of OFPGT_*. */
    uint8_t pad;            /* Pad to 64 bits. */
    uint32_t group_id;      /* Group identifier. */
    struct ofp_bucket buckets[0]; /* List of buckets - 0 or more. */
};
OFP_ASSERT(sizeof(struct ofp_group_desc) == 8);


// 7.3.5.11 Group Features

/* Body of reply to OFPMP_GROUP_FEATURES request. Group features. */
struct ofp_group_features {
    uint32_t types;         /* Bitmap of OFPGT_* values supported. */
    uint32_t capabilities;  /* Bitmap of OFPGFC_* capability supported. */
    uint32_t max_groups[4]; /* Maximum number of groups for each type. */
    uint32_t actions[4];    /* Bitmaps of OFPAT_* that are supported. */
};
OFP_ASSERT(sizeof(struct ofp_group_features) == 40);

/* Group configuration flags */
enum ofp_group_capabilities {
    OFPGFC_SELECT_WEIGHT   = 1 << 0, /* Support weight for select groups */
    OFPGFC_SELECT_LIVENESS = 1 << 1, /* Support liveness for select groups */
    OFPGFC_CHAINING        = 1 << 2, /* Support chaining groups */
    OFPGFC_CHAINING_CHECKS = 1 << 3  /* Check chaining for loops and delete */
};


// 7.3.5.12 Meter Statistics

/* Body of OFPMP_METER and OFPMP_METER_CONFIG requests. */
struct ofp_meter_multipart_request {
    uint32_t meter_id;      /* Meter instance, or OFPM_ALL. */
    uint8_t pad[4];         /* Align to 64 bits. */
};
OFP_ASSERT(sizeof(struct ofp_meter_multipart_request) == 8);

/* Statistics for each meter band */
struct ofp_meter_band_stats {
    uint64_t packet_band_count; /* Number of packets in band. */
    uint64_t byte_band_count;   /* Number of bytes in band. */
};
OFP_ASSERT(sizeof(struct ofp_meter_band_stats) == 16);

/* Body of reply to OFPMP_METER request. Meter statistics. */
struct ofp_meter_stats {
    uint32_t meter_id;          /* Meter instance. */
    uint16_t len;               /* Length in bytes of this stats. */
    uint8_t pad[6];
    uint32_t flow_count;        /* Number of flows bound to meter. */
    uint64_t packet_in_count;   /* Number of packets in input. */
    uint64_t byte_in_count;     /* Number of bytes in input. */
    uint32_t duration_sec;  /* Time meter has been alive in seconds. */
    uint32_t duration_nsec; /* Time meter has been alive in nanoseconds beyond
                               duration_sec. */
    struct ofp_meter_band_stats band_stats[0]; /* The band_stats length is
                                            inferred from the length field. */
};
OFP_ASSERT(sizeof(struct ofp_meter_stats) == 40);


// 7.3.5.13 Meter Configuration Statistics

/* Body of reply to OFPMP_METER_CONFIG request. Meter configuration. */
struct ofp_meter_config {
    uint16_t length;        /* Length of this entry. */
    uint16_t flags;         /* All OFPMF_* that apply. */
    uint32_t meter_id;      /* Meter instance. */
    struct ofp_meter_band_header bands[0]; /* The bands length is
                                        inferred from the length field. */
};
OFP_ASSERT(sizeof(struct ofp_meter_config) == 8);


// 7.3.5.14 Meter Features Statistics

/* Body of reply to OFPMP_METER_FEATURES request. Meter features. */
struct ofp_meter_features {
    uint32_t max_meter;     /* Maximum number of meters. */
    uint32_t band_types;    /* Bitmaps of OFPMBT_* values supported. */
    uint32_t capabilities;  /* Bitmaps of "ofp_meter_flags". */
    uint8_t max_bands;      /* Maximum bands per meters */
    uint8_t max_color;      /* Maximum color value */
    uint8_t pad[2];
};
OFP_ASSERT(sizeof(struct ofp_meter_features) == 16);


// 7.3.5.15 Experimenter Multipart

/* Body for ofp_multipart_request/reply of type OFPMP_EXPERIMENTER. */
struct ofp_experimenter_multipart_header {
    uint32_t experimenter;  /* Experimenter ID which takes the same form
                               as in struct ofp_experimenter_header. */
    uint32_t exp_type;      /* Experimenter defined. */
    /* Experimenter-defined arbitrary additional data. */
};
OFP_ASSERT(sizeof(struct ofp_experimenter_multipart_header) == 8);


// 7.3.6  Queue Configuration Messages

/* Query for port queue configuration. */
struct ofp_queue_get_config_request {
    struct ofp_header header;
    uint32_t port;          /* Port to be queried. Should refer
                               to a valid physical port (i.e. <= OFPP_MAX),
                               or OFPP_ANY to request all configured
                               queues. */
    uint8_t pad[4];
};
OFP_ASSERT(sizeof(struct ofp_queue_get_config_request) == 16);

/* Queue configuration for a given port. */
struct ofp_queue_get_config_reply {
    struct ofp_header header;
    uint32_t port;
    uint8_t pad[4];
    struct ofp_packet_queue queues[0]; /* List of configured queues. */
};
OFP_ASSERT(sizeof(struct ofp_queue_get_config_reply) == 16);


// 7.3.7  Packet-Out Message

/* Send packet (controller -> datapath). */
struct ofp_packet_out {
    struct ofp_header header;
    uint32_t buffer_id;     /* ID assigned by datapath (OFP_NO_BUFFER
                               if none). */
    uint32_t in_port;       /* Packet's input port or OFPP_CONTROLLER. */
    uint16_t actions_len;   /* Size of action array in bytes. */
    uint8_t pad[6];
    struct ofp_action_header actions[0]; /* Action list - o or more. */
    /* The variable size action list is optionally followed by packet data.
     * This data is only present and meaningful if buffer_id == -1. */
    /* uint8_t data[0]; */ /* Packet data. The length is inferred
                              from the length field in the header. */
};
OFP_ASSERT(sizeof(struct ofp_packet_out) == 24);

/* if the buffer_id is OFP_NO_BUFFER, then the packet data is included in the data array */
#define OFP_NO_BUFFER 0xffffffff


// 7.3.8  Barrier Message


// 7.3.9  Role Request Message

/* Role request and reply message. */
struct ofp_role_request {
    struct ofp_header header;   /* Type OFPT_ROLE_REQUEST/OFPT_ROLE_REPLY. */
    uint32_t role;              /* One of OFPCR_ROLE_*. */
    uint8_t pad[4];             /* Align to 64 bits. */
    uint64_t generation_id;     /* Master Election Generation Id */
};
OFP_ASSERT(sizeof(struct ofp_role_request) == 24);

/* Configures the "role" of the sending controller. The default role is:
 *
 * - Equal (OFPCR_ROLE_EQUAL), which allows the controller access to all
 * OpenFlow features. All controllers have equal responsibility.
 *
 * The other possible roles are a related pair:
 *
 * - Master (OFPCR_ROLE_MASTER) is equivalent to Equal, except that there
 * may be at most one Master controller at a time: when a controller
 * configures itself as Master, any existing Master is demoted to the
 * Slave role.
 *
 * - Slave (OFPCR_ROLE_SLAVE) allows the controller read-only access to
 * OpenFlow features. In particular attempts to modify the flow table
 * will be rejected with an OFPBRC_EPERM error.
 *
 * Slave controllers do not receive OFPT_PACKET_IN or OFPT_FLOW_REMOVED
 * messages, but they do receive OFPT_PORT_STATUS messages.
 */
/* Controller roles. */
enum ofp_controller_role {
    OFPCR_ROLE_NOCHANGE = 0, /* Don't change current role. */
    OFPCR_ROLE_EQUAL    = 1, /* Default role, full access. */
    OFPCR_ROLE_MASTER   = 2, /* Full access, at most one master. */
    OFPCR_ROLE_SLAVE    = 3  /* Read-only access. */
};


// 7.3.10  Set Asynchronous Configuration Message

/* Asynchronous message configuration. */
struct ofp_async_config {
    struct ofp_header header;       /* OFPT_GET_ASYNC_REPLY or OFPT_SET_ASYNC. */
    uint32_t packet_in_mask[2];     /* Bitmasks of OFPR_* values. */
    uint32_t port_status_mask[2];   /* Bitmasks of OFPPR_* values. */
    uint32_t flow_removed_mask[2];  /* Bitmasks of OFPRR_* values. */
};
OFP_ASSERT(sizeof(struct ofp_async_config) == 32);


// 7.4  Asynchronous Messages

// 7.4.1  Packet-In Message

/* Packet received on port (datapath -> controller). */
struct ofp_packet_in {
    struct ofp_header header;
    uint32_t buffer_id;     /* ID assigned by datapath. */
    uint16_t total_len;     /* Full length of frame. */
    uint8_t reason;         /* Reason packet is being sent (one of OFPR_*) */
    uint8_t table_id;       /* ID of the table that was looked up */
    uint64_t cookie;        /* Cookie of the flow entry that was looked up. */
    struct ofp_match match; /* Packet metadata. Variable size. */
    /* The variable size and padded match is always followed by:
     *  - Exactly 2 all-zero padding bytes, then
     *  - An Ethernet frame whose length is inferred from header.length.
     * The padding bytes preceding the Ethernet frame ensure that the IP
     * header (if any) following the Ethernet header is 32-bit aligned.
     */
    //uint8_t pad[2];       /* Align to 64 bit + 16 bit */
    //uint8_t data[0];      /* Ethernet frame */
};
OFP_ASSERT(sizeof(struct ofp_packet_in) == 32);

/* Why is this packet being sent to the controller? */
enum ofp_packet_in_reason {
    OFPR_NO_MATCH    = 0, /* No matching flow (table-miss flow entry). */
    OFPR_ACTION      = 1, /* Action explicitly output to controller. */
    OFPR_INVALID_TTL = 2  /* Packet has invalid TTL */
};


// 7.4.2  Flow Removed Message

/* Flow removed (datapath -> controller). */
struct ofp_flow_removed {
    struct ofp_header header;
    uint64_t cookie;        /* Opaque controller-issued identifier. */

    uint16_t priority;      /* Priority level of flow entry. */
    uint8_t reason;         /* One of OFPRR_*. */
    uint8_t table_id;       /* ID of the table */

    uint32_t duration_sec;  /* Time flow was alive in seconds. */
    uint32_t duration_nsec; /* Time flow was alive in nanoseconds beyond
                               duration_sec. */
    uint16_t idle_timeout;  /* Idle timeout from original flow mod. */
    uint16_t hard_timeout;  /* Hard timeout from original flow mod. */
    uint64_t packet_count;
    uint64_t byte_count;
    struct ofp_match match; /* Description of fields. Variable size. */
};
OFP_ASSERT(sizeof(struct ofp_flow_removed) == 56);

/* Why was this flow removed? */
enum ofp_flow_removed_reason {
    OFPRR_IDLE_TIMEOUT = 0, /* Flow idle time exceeded idle_timeout. */
    OFPRR_HARD_TIMEOUT = 1, /* Time exceeded hard_timeout. */
    OFPRR_DELETE       = 2, /* Evicted by a DELETE flow mod. */
    OFPRR_GROUP_DELETE = 3  /* Group was removed. */
};


// 7.4.3  Port Status Message

/* A physical port has changed in the datapath */
struct ofp_port_status {
    struct ofp_header header;
    uint8_t reason;         /* One of OFPPR_*. */
    uint8_t pad[7];         /* Align to 64-bits. */
    struct ofp_port desc;
};
OFP_ASSERT(sizeof(struct ofp_port_status) == 80);

/* What changed about the physical port */
enum ofp_port_reason {
    OFPPR_ADD    = 0, /* The port was added. */
    OFPPR_DELETE = 1, /* The port was removed. */
    OFPPR_MODIFY = 2  /* Some attribute of the port has changed. */
};


// 7.4.4  Error Message

/* OFPT_ERROR: Error message (datapath -> controller). */
struct ofp_error_msg {
    struct ofp_header header;
    uint16_t type;
    uint16_t code;
    uint8_t data[0];    /* Variable-length data. Interpreted based
                           on the type and code. No padding. */
};
OFP_ASSERT(sizeof(struct ofp_error_msg) == 12);

/* Values for 'type' in ofp_error_message. These values are immutable: they
 * will not change in future versions of the protocol (although new values may
 * be added). */
enum ofp_error_type {
    OFPET_HELLO_FAILED          = 0,  /* Hello protocol failed. */
    OFPET_BAD_REQUEST           = 1,  /* Request was not understood. */
    OFPET_BAD_ACTION            = 2,  /* Error in action description. */
    OFPET_BAD_INSTRUCTION       = 3,  /* Error in instruction list. */
    OFPET_BAD_MATCH             = 4,  /* Error in match. */
    OFPET_FLOW_MOD_FAILED       = 5,  /* Problem modifying flow entry. */
    OFPET_GROUP_MOD_FAILED      = 6,  /* Problem modifying group entry. */
    OFPET_PORT_MOD_FAILED       = 7,  /* Port mod request failed. */
    OFPET_TABLE_MOD_FAILED      = 8,  /* Table mod request failed. */
    OFPET_QUEUE_OP_FAILED       = 9,  /* Queue operation failed. */
    OFPET_SWITCH_CONFIG_FAILED  = 10, /* Switch config request failed. */
    OFPET_ROLE_REQUEST_FAILED   = 11, /* Controller Role request failed. */
    OFPET_METER_MOD_FAILED      = 12, /* Error in meter. */
    OFPET_TABLE_FEATURES_FAILED = 13, /* Setting table features failed. */
    OFPET_EXPERIMENTER          = 0xffff /* Experimenter error messages. */
};

/* ofp_error_msg 'code' values for OFPET_HELLO_FAILED. 'data' contains an
 * ASCII text string that may give failure details. */
enum ofp_hello_failed_code {
    OFPHFC_INCOMPATIBLE = 0, /* No compatible version. */
    OFPHFC_EPERM        = 1  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_BAD_REQUEST. 'data' contains at least
 * the first 64 bytes of the failed request. */
enum ofp_bad_request_code {
    OFPBRC_BAD_VERSION      = 0,  /* ofp_header.version not supported. */
    OFPBRC_BAD_TYPE         = 1,  /* ofp_header.type not supported. */
    OFPBRC_BAD_MULTIPART    = 2,  /* ofp_multipart_request.type not
                                     supported. */
    OFPBRC_BAD_EXPERIMENTER = 3,  /* Experimenter id not supported
                                     (in ofp_experimenter_header or
                                     ofp_multipart_request or
                                     ofp_multipart_reply). */
    OFPBRC_BAD_EXP_TYPE     = 4,  /* Experimenter type not supported. */
    OFPBRC_EPERM            = 5,  /* Permissions error. */
    OFPBRC_BAD_LEN          = 6,  /* Wrong request length for type. */
    OFPBRC_BUFFER_EMPTY     = 7,  /* Specified buffer has already been used. */
    OFPBRC_BUFFER_UNKNOWN   = 8,  /* Specified buffer does not exist. */
    OFPBRC_BAD_TABLE_ID     = 9,  /* Specified table-id invalid or does not
                                     exist. */
    OFPBRC_IS_SLAVE         = 10, /* Denied because controller is slave. */
    OFPBRC_BAD_PORT         = 11, /* Invalid port. */
    OFPBRC_BAD_PACKET       = 12, /* Invalid packet in packet-out. */
    OFPBRC_MULTIPART_BUFFER_OVERFLOW = 13  /* ofp_multipart_request
                                            overflowed the assigned buffer. */
};

/* ofp_error_msg 'code' values for OFPET_BAD_ACTION. 'data' contains at least
 * the first 64 bytes of the failed request. */
enum ofp_bad_action_code {
    OFPBAC_BAD_TYPE           = 0,  /* Unknown action type. */
    OFPBAC_BAD_LEN            = 1,  /* Length problem in actions. */
    OFPBAC_BAD_EXPERIMENTER   = 2,  /* Unknown experimenter id specified. */
    OFPBAC_BAD_EXP_TYPE       = 3,  /* Unknown action for experimenter id. */
    OFPBAC_BAD_OUT_PORT       = 4,  /* Problem validating output port. */
    OFPBAC_BAD_ARGUMENT       = 5,  /* Bad action argument. */
    OFPBAC_EPERM              = 6,  /* Permissions error. */
    OFPBAC_TOO_MANY           = 7,  /* Can't handle this many actions. */
    OFPBAC_BAD_QUEUE          = 8,  /* Problem validating output queue. */
    OFPBAC_BAD_OUT_GROUP      = 9,  /* Invalid group id in forward action. */
    OFPBAC_MATCH_INCONSISTENT = 10, /* Action can't apply for this match,
                                       or Set-Field missing prerequisite. */
    OFPBAC_UNSUPPORTED_ORDER  = 11, /* Action order is unsupported for the
                                 action list in an Apply-Actions instruction */
    OFPBAC_BAD_TAG            = 12, /* Actions uses an unsupported
                                       tag/encap. */
    OFPBAC_BAD_SET_TYPE       = 13, /* Unsupported type in SET_FIELD action. */
    OFPBAC_BAD_SET_LEN        = 14, /* Length problem in SET_FIELD action. */
    OFPBAC_BAD_SET_ARGUMENT   = 15  /* Bad argument in SET_FIELD action. */
};

/* ofp_error_msg 'code' values for OFPET_BAD_INSTRUCTION. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_bad_instruction_code {
    OFPBIC_UNKNOWN_INST     = 0, /* Unknown instruction. */
    OFPBIC_UNSUP_INST       = 1, /* Switch or table does not support the
                                    instruction. */
    OFPBIC_BAD_TABLE_ID     = 2, /* Invalid Table-ID specified. */
    OFPBIC_UNSUP_METADATA   = 3, /* Metadata value unsupported by datapath. */
    OFPBIC_UNSUP_METADATA_MASK = 4, /* Metadata mask value unsupported by
                                       datapath. */
    OFPBIC_BAD_EXPERIMENTER = 5, /* Unknown experimenter id specified. */
    OFPBIC_BAD_EXP_TYPE     = 6, /* Unknown instruction for experimenter id. */
    OFPBIC_BAD_LEN          = 7, /* Length problem in instructions. */
    OFPBIC_EPERM            = 8  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_BAD_MATCH. 'data' contains at least
 * the first 64 bytes of the failed request. */
enum ofp_bad_match_code {
    OFPBMC_BAD_TYPE         = 0,  /* Unsupported match type specified by the
                                     match */
    OFPBMC_BAD_LEN          = 1,  /* Length problem in match. */
    OFPBMC_BAD_TAG          = 2,  /* Match uses an unsupported tag/encap. */
    OFPBMC_BAD_DL_ADDR_MASK = 3,  /* Unsupported datalink addr mask - switch
                                     does not support arbitrary datalink
                                     address mask. */
    OFPBMC_BAD_NW_ADDR_MASK = 4,  /* Unsupported network addr mask - switch
                                     does not support arbitrary network
                                     address mask. */
    OFPBMC_BAD_WILDCARDS    = 5,  /* Unsupported combination of fields masked
                                     or omitted in the match. */
    OFPBMC_BAD_FIELD        = 6,  /* Unsupported field type in the match. */
    OFPBMC_BAD_VALUE        = 7,  /* Unsupported value in a match field. */
    OFPBMC_BAD_MASK         = 8,  /* Unsupported mask specified in the match,
                                     field is not dl-address or nw-address. */
    OFPBMC_BAD_PREREQ       = 9,  /* A prerequisite was not met. */
    OFPBMC_DUP_FIELD        = 10, /* A field type was duplicated. */
    OFPBMC_EPERM            = 11  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_FLOW_MOD_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_flow_mod_failed_code {
    OFPFMFC_UNKNOWN      = 0, /* Unspecified error. */
    OFPFMFC_TABLE_FULL   = 1, /* Flow not added because table was full. */
    OFPFMFC_BAD_TABLE_ID = 2, /* Table does not exist */
    OFPFMFC_OVERLAP      = 3, /* Attempted to add overlapping flow with
                                 CHECK_OVERLAP flag set. */
    OFPFMFC_EPERM        = 4, /* Permissions error. */
    OFPFMFC_BAD_TIMEOUT  = 5, /* Flow not added because of unsupported
                                 idle/hard timeout. */
    OFPFMFC_BAD_COMMAND  = 6, /* Unsupported or unknown command. */
    OFPFMFC_BAD_FLAGS    = 7  /* Unsupported or unknown flags. */
};

/* ofp_error_msg 'code' values for OFPET_GROUP_MOD_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_group_mod_failed_code {
    OFPGMFC_GROUP_EXISTS       = 0,  /* Group not added because a group ADD
                                        attempted to replace an
                                        already-present group. */
    OFPGMFC_INVALID_GROUP      = 1,  /* Group not added because Group
                                        specified is invalid. */
    OFPGMFC_WEIGHT_UNSUPPORTED = 2,  /* Switch does not support unequal load
                                        sharing with select groups. */
    OFPGMFC_OUT_OF_GROUPS      = 3,  /* The group table is full. */
    OFPGMFC_OUT_OF_BUCKETS     = 4,  /* The maximum number of action buckets
                                        for a group has been exceeded. */
    OFPGMFC_CHAINING_UNSUPPORTED = 5,   /* Switch does not support groups that
                                           forward to groups. */
    OFPGMFC_WATCH_UNSUPPORTED  = 6,  /* This group cannot watch the watch_port
                                        or watch_group specified. */
    OFPGMFC_LOOP               = 7,  /* Group entry would cause a loop. */
    OFPGMFC_UNKNOWN_GROUP      = 8,  /* Group not modified because a group
                                        MODIFY attempted to modify a
                                        non-existent group. */
    OFPGMFC_CHAINED_GROUP      = 9,  /* Group not deleted because another
                                        group is forwarding to it. */
    OFPGMFC_BAD_TYPE           = 10, /* Unsupported or unknown group type. */
    OFPGMFC_BAD_COMMAND        = 11, /* Unsupported or unknown command. */
    OFPGMFC_BAD_BUCKET         = 12, /* Error in bucket. */
    OFPGMFC_BAD_WATCH          = 13, /* Error in watch port/group. */
    OFPGMFC_EPERM              = 14  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_PORT_MOD_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_port_mod_failed_code {
    OFPPMFC_BAD_PORT      = 0, /* Specified port number does not exist. */
    OFPPMFC_BAD_HW_ADDR   = 1, /* Specified hardware address does not
                                  match the port number. */
    OFPPMFC_BAD_CONFIG    = 2, /* Specified config is invalid. */
    OFPPMFC_BAD_ADVERTISE = 3, /* Specified advertise is invalid. */
    OFPPMFC_EPERM         = 4  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_TABLE_MOD_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_table_mod_failed_code {
    OFPTMFC_BAD_TABLE  = 0, /* Specified table does not exist. */
    OFPTMFC_BAD_CONFIG = 1, /* Specified config is invalid. */
    OFPTMFC_EPERM      = 2  /* Permissions error. */
};

/* ofp_error msg 'code' values for OFPET_QUEUE_OP_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request */
enum ofp_queue_op_failed_code {
    OFPQOFC_BAD_PORT  = 0, /* Invalid port (or port does not exist). */
    OFPQOFC_BAD_QUEUE = 1, /* Queue does not exist. */
    OFPQOFC_EPERM     = 2  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_SWITCH_CONFIG_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_switch_config_failed_code {
    OFPSCFC_BAD_FLAGS = 0, /* Specified flags is invalid. */
    OFPSCFC_BAD_LEN   = 1, /* Specified len is invalid. */
    OFPSCFC_EPERM     = 2  /* Permissions error. */
};

/* ofp_error_msg 'code' values for OFPET_ROLE_REQUEST_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_role_request_failed_code {
    OFPRRFC_STALE    = 0, /* Stale Message: old generation_id. */
    OFPRRFC_UNSUP    = 1, /* Controller role change unsupported. */
    OFPRRFC_BAD_ROLE = 2  /* Invalid role. */
};

/* ofp_error_msg 'code' values for OFPET_METER_MOD_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_meter_mod_failed_code {
    OFPMMFC_UNKNOWN        = 0,  /* Unspecified error. */
    OFPMMFC_METER_EXISTS   = 1,  /* Meter not added because a Meter ADD
                                    attempted to replace an existing Meter. */
    OFPMMFC_INVALID_METER  = 2,  /* Meter not added because Meter specified
                                    is invalid. */
    OFPMMFC_UNKNOWN_METER  = 3,  /* Meter not modified because a Meter
                                    MODIFY attempted to modify a non-existent
                                    Meter. */
    OFPMMFC_BAD_COMMAND    = 4,  /* Unsupported or unknown command. */
    OFPMMFC_BAD_FLAGS      = 5,  /* Flag configuration unsupported. */
    OFPMMFC_BAD_RATE       = 6,  /* Rate unsupported. */
    OFPMMFC_BAD_BURST      = 7,  /* Burst size unsupported. */
    OFPMMFC_BAD_BAND       = 8,  /* Band unsupported. */
    OFPMMFC_BAD_BAND_VALUE = 9,  /* Band value unsupported. */
    OFPMMFC_OUT_OF_METERS  = 10, /* No more meters available. */
    OFPMMFC_OUT_OF_BANDS   = 11  /* The maximum number of properties
                                    for a meter has been exceeded. */
};

/* ofp_error_msg 'code' values for OFPET_TABLE_FEATURES_FAILED. 'data' contains
 * at least the first 64 bytes of the failed request. */
enum ofp_table_features_failed_code {
    OFPTFFC_BAD_TABLE    = 0, /* Specified table does not exist. */
    OFPTFFC_BAD_METADATA = 1, /* Invalid metadata mask. */
    OFPTFFC_BAD_TYPE     = 2, /* Unknown property type. */
    OFPTFFC_BAD_LEN      = 3, /* Length problem in properties. */
    OFPTFFC_BAD_ARGUMENT = 4, /* Unsupported property value. */
    OFPTFFC_EPERM        = 5  /* Permissions error. */
};

/* OFPET_EXPERIMENTER: Error message (datapath -> controller). */
struct ofp_error_experimenter_msg {
    struct ofp_header header;
    uint16_t type;          /* OFPET_EXPERIMENTER. */
    uint16_t exp_type;      /* Experimenter defined. */
    uint32_t experimenter;  /* Experimenter ID which takes the same form
                               as in struct ofp_experimenter_header. */
    uint8_t data[0];        /* Variable-length data. Interpreted based
                               on the type and code. No padding. */
};
OFP_ASSERT(sizeof(struct ofp_error_experimenter_msg) == 16);


// 7.5  Symmetric Messages

// 7.5.1  Hello

/* Common header for all Hello Elements */
struct ofp_hello_elem_header {
    uint16_t type;   /* One of OFPHET_*. */
    uint16_t length; /* Length in bytes of this element. */
};
OFP_ASSERT(sizeof(struct ofp_hello_elem_header) == 4);

/* Hello elements types.
*/
enum ofp_hello_elem_type {
    OFPHET_VERSIONBITMAP = 1, /* Bitmap of version supported. */
};

/* Version bitmap Hello Element */
struct ofp_hello_elem_versionbitmap {
   uint16_t type;   /* OFPHET_VERSIONBITMAP. */
   uint16_t length; /* Length in bytes of this element. */
   /* Followed by:
    *  - Exactly (length - 4) bytes containing the bitmaps, then
    *  - Exactly (length + 7)/8*8 - (length) (between 0 and 7)
    *    bytes of all-zero bytes */
   uint32_t bitmaps[0]; /* List of bitmaps - supported versions */
};
OFP_ASSERT(sizeof(struct ofp_hello_elem_versionbitmap) == 4);

/* OFPT_HELLO. This message includes zero or more hello elements having
* variable size. Unknown elements types must be ignored/skipped, to allow
* for future extensions. */
struct ofp_hello {
    struct ofp_header header;

    /* Hello element list */
    struct ofp_hello_elem_header elements[0]; /* List of elements - 0 or more */
};
OFP_ASSERT(sizeof(struct ofp_hello) == 8);


// 7.5.2  Echo Request


// 7.5.3  Echo Reply


// 7.5.4  Experimenter

/* Experimenter extension. */
struct ofp_experimenter_header {
    struct ofp_header header;   /* Type OFPT_EXPERIMENTER. */
    uint32_t experimenter;      /* Experimenter ID:
                                 * - MSB 0: low-order bytes are IEEE OUI.
                                 * - MSB != 0: defined by ONF. */
    uint32_t exp_type;          /* Experimenter defined. */
    /* Experimenter-defined arbitrary additional data. */
};
OFP_ASSERT(sizeof(struct ofp_experimenter_header) == 16);

#endif /* openflow.h */


/*
 * Local variables:
 * c-basic-offset: 4
 * indent-tabs-mode: nil
 * End:
 */