#ifndef CEPH_MSGR_H
	#define CEPH_MSGR_H
	
	#ifndef __KERNEL__
	#include <sys/socket.h> // for struct sockaddr_storage
	#endif
	
	#include "include/int_types.h"
	
	/* See comment in ceph_fs.h.  */
	#ifndef __KERNEL__
	#include "byteorder.h"
	#define __le16 ceph_le16
	#define __le32 ceph_le32
	#define __le64 ceph_le64
	#endif
	
	/*
	 * Data types for message passing layer used by Ceph.
	 */
	
	#define CEPH_MON_PORT_LEGACY    6789  /* legacy default monitor port */
	#define CEPH_MON_PORT_IANA      3300  /* IANA monitor port */
	
	/*
	 * client-side processes will try to bind to ports in this
	 * range, simply for the benefit of tools like nmap or wireshark
	 * that would like to identify the protocol.
	 */
	#define CEPH_PORT_FIRST  6789
	
	/*
	 * tcp connection banner.  include a protocol version. and adjust
	 * whenever the wire protocol changes.  try to keep this string length
	 * constant.
	 */
	#define CEPH_BANNER "ceph v027"
	
	
	/*
	 * messenger V2 connection banner prefix.
	 * The full banner string should have the form: "ceph v2\n<le16>"
	 * the 2 bytes are the length of the remaining banner.
	 */
	#define CEPH_BANNER_V2_PREFIX "ceph v2\n"
	
	/*
	 * messenger V2 features
	 */
	#define CEPH_MSGR2_INCARNATION_1 (0ull)
	
	#define DEFINE_MSGR2_FEATURE(bit, incarnation, name)               \
		const static uint64_t CEPH_MSGR2_FEATURE_##name = (1ULL << bit); \
		const static uint64_t CEPH_MSGR2_FEATUREMASK_##name =            \
				(1ULL << bit | CEPH_FEATURE_INCARNATION_##incarnation);
	
	#define HAVE_MSGR2_FEATURE(x, name) \
		(((x) & (CEPH_MSGR2_FEATUREMASK_##name)) == (CEPH_MSGR2_FEATUREMASK_##name))
	
	
	#define CEPH_MSGR2_SUPPORTED_FEATURES (0ull)
	
	#define CEPH_MSGR2_REQUIRED_FEATURES (CEPH_MSGR2_SUPPORTED_FEATURES)
	
	
	/*
	 * Rollover-safe type and comparator for 32-bit sequence numbers.
	 * Comparator returns -1, 0, or 1.
	 */
	typedef __u32 ceph_seq_t;
	
	static inline __s32 ceph_seq_cmp(__u32 a, __u32 b)
	{
	       return (__s32)a - (__s32)b;
	}
	
	
	/*
	 * entity_name -- logical name for a process participating in the
	 * network, e.g. 'mds0' or 'osd3'.
	 */
	struct ceph_entity_name {
		__u8 type;      /* CEPH_ENTITY_TYPE_* */
		__le64 num;
	} __attribute__ ((packed));
	
	#define CEPH_ENTITY_TYPE_MON    0x01
	#define CEPH_ENTITY_TYPE_MDS    0x02
	#define CEPH_ENTITY_TYPE_OSD    0x04
	#define CEPH_ENTITY_TYPE_CLIENT 0x08
	#define CEPH_ENTITY_TYPE_MGR    0x10
	#define CEPH_ENTITY_TYPE_AUTH   0x20
	
	#define CEPH_ENTITY_TYPE_ANY    0xFF
	
	extern const char *ceph_entity_type_name(int type);
	
	/*
	 * entity_addr -- network address
	 */
	struct ceph_entity_addr {
		__le32 type;
		__le32 nonce;  /* unique id for process (e.g. pid) */
		struct sockaddr_storage in_addr;
	} __attribute__ ((packed));
	
	struct ceph_entity_inst {
		struct ceph_entity_name name;
		struct ceph_entity_addr addr;
	} __attribute__ ((packed));
	
	
	/* used by message exchange protocol */
	#define CEPH_MSGR_TAG_READY         1  /* server->client: ready for messages */
	#define CEPH_MSGR_TAG_RESETSESSION  2  /* server->client: reset, try again */
	#define CEPH_MSGR_TAG_WAIT          3  /* server->client: wait for racing
						  incoming connection */
	#define CEPH_MSGR_TAG_RETRY_SESSION 4  /* server->client + cseq: try again
						  with higher cseq */
	#define CEPH_MSGR_TAG_RETRY_GLOBAL  5  /* server->client + gseq: try again
						  with higher gseq */
	#define CEPH_MSGR_TAG_CLOSE         6  /* closing pipe */
	#define CEPH_MSGR_TAG_MSG           7  /* message */
	#define CEPH_MSGR_TAG_ACK           8  /* message ack */
	#define CEPH_MSGR_TAG_KEEPALIVE     9  /* just a keepalive byte! */
	#define CEPH_MSGR_TAG_BADPROTOVER  10  /* bad protocol version */
	#define CEPH_MSGR_TAG_BADAUTHORIZER 11 /* bad authorizer */
	#define CEPH_MSGR_TAG_FEATURES      12 /* insufficient features */
	#define CEPH_MSGR_TAG_SEQ           13 /* 64-bit int follows with seen seq number */
	#define CEPH_MSGR_TAG_KEEPALIVE2     14
	#define CEPH_MSGR_TAG_KEEPALIVE2_ACK 15  /* keepalive reply */
	#define CEPH_MSGR_TAG_CHALLENGE_AUTHORIZER 16  /* ceph v2 doing server challenge */
	
	/*
	 * connection negotiation
	 */
	struct ceph_msg_connect {
		__le64 features;     /* supported feature bits */
		__le32 host_type;    /* CEPH_ENTITY_TYPE_* */
		__le32 global_seq;   /* count connections initiated by this host */

		__le32 connect_seq;  /* count connections initiated in this session */

		__le32 protocol_version;

		__le32 authorizer_protocol;

		__le32 authorizer_len;

		__u8  flags;         /* CEPH_MSG_CONNECT_* */
	} __attribute__ ((packed));
	
	struct ceph_msg_connect_reply {

		__u8 tag;

		__le64 features;     /* feature bits for this session */

		__le32 global_seq;

		__le32 connect_seq;

		__le32 protocol_version;

		__le32 authorizer_len;

		__u8 flags;
	} __attribute__ ((packed));
	
	#define CEPH_MSG_CONNECT_LOSSY  1  /* messages i send may be safely dropped */
	
	
	/*
	 * message header
	 */
	struct ceph_msg_header_old {
		__le64 seq;       /* message seq# for this session */
		__le64 tid;       /* transaction id */
		__le16 type;      /* message type */
		__le16 priority;  /* priority.  higher value == higher priority */
		__le16 version;   /* version of message encoding */
	
		__le32 front_len; /* bytes in main payload */
		__le32 middle_len;/* bytes in middle payload */
		__le32 data_len;  /* bytes of data payload */
		__le16 data_off;  /* sender: include full offset;
				     receiver: mask against ~PAGE_MASK */
	
		struct ceph_entity_inst src, orig_src;
		__le32 reserved;
		__le32 crc;       /* header crc32c */
	} __attribute__ ((packed));
	
	struct ceph_msg_header {

		__le64 seq;       /* message seq# for this session */

		__le64 tid;       /* transaction id */

		__le16 type;      /* message type */

		__le16 priority;  /* priority.  higher value == higher priority */

		__le16 version;   /* version of message encoding */
	

		__le32 front_len; /* bytes in main payload */

		__le32 middle_len;/* bytes in middle payload */

		__le32 data_len;  /* bytes of data payload */

		__le16 data_off;  /* sender: include full offset;
				     receiver: mask against ~PAGE_MASK */
	

		struct ceph_entity_name src;
	
		/* oldest code we think can decode this.  unknown if zero. */

		__le16 compat_version;

		__le16 reserved;

		__le32 crc;       /* header crc32c */
	} __attribute__ ((packed));
	
	struct ceph_msg_header2 {
		__le64 seq;       /* message seq# for this session */
		__le64 tid;       /* transaction id */
		__le16 type;      /* message type */
		__le16 priority;  /* priority.  higher value == higher priority */
		__le16 version;   /* version of message encoding */
	
		__le32 data_pre_padding_len;
		__le16 data_off;  /* sender: include full offset;
				     receiver: mask against ~PAGE_MASK */
	
		__le64 ack_seq;
		__u8 flags;
		/* oldest code we think can decode this.  unknown if zero. */
		__le16 compat_version;
		__le16 reserved;
	} __attribute__ ((packed));
	
	#define CEPH_MSG_PRIO_LOW     64
	#define CEPH_MSG_PRIO_DEFAULT 127
	#define CEPH_MSG_PRIO_HIGH    196
	#define CEPH_MSG_PRIO_HIGHEST 255
	
	/*
	 * follows data payload
	 * ceph_msg_footer_old does not support digital signatures on messages PLR
	 */
	
	struct ceph_msg_footer_old {
		__le32 front_crc, middle_crc, data_crc;
		__u8 flags;
	} __attribute__ ((packed));
	
	struct ceph_msg_footer {
		__le32 front_crc, middle_crc, data_crc;
		// sig holds the 64 bits of the digital signature for the message PLR
		__le64  sig;
		__u8 flags;
	} __attribute__ ((packed));
	
	#define CEPH_MSG_FOOTER_COMPLETE  (1<<0)   /* msg wasn't aborted */
	#define CEPH_MSG_FOOTER_NOCRC     (1<<1)   /* no data crc */
	#define CEPH_MSG_FOOTER_SIGNED	  (1<<2)   /* msg was signed */
	
	#ifndef __KERNEL__
	#undef __le16
	#undef __le32
	#undef __le64
	#endif
	
	#endif