From 0dee3c28af2fbe22ca62739a7f57da5435d35793 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 6 Oct 2009 11:31:06 -0700 Subject: ceph: on-wire types These headers describe the types used to exchange messages between the Ceph client and various servers. All types are little-endian and packed. These headers are shared between the kernel and userspace, so all types are in terms of e.g. __u32. Additionally, we define a few magic values to identify the current version of the protocol(s) in use, so that discrepancies to be detected on mount. Signed-off-by: Sage Weil --- fs/ceph/msgr.h | 157 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 fs/ceph/msgr.h (limited to 'fs/ceph/msgr.h') diff --git a/fs/ceph/msgr.h b/fs/ceph/msgr.h new file mode 100644 index 000000000000..73921ae43faa --- /dev/null +++ b/fs/ceph/msgr.h @@ -0,0 +1,157 @@ +#ifndef __MSGR_H +#define __MSGR_H + +/* + * Data types for message passing layer used by Ceph. + */ + +#define CEPH_MON_PORT 6789 /* default 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 +#define CEPH_PORT_START 6800 /* non-monitors start here */ +#define CEPH_PORT_LAST 6900 + +/* + * 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 v021" +#define CEPH_BANNER_MAX_LEN 30 + + +/* + * 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 1 +#define CEPH_ENTITY_TYPE_MDS 2 +#define CEPH_ENTITY_TYPE_OSD 3 +#define CEPH_ENTITY_TYPE_CLIENT 4 +#define CEPH_ENTITY_TYPE_ADMIN 5 + +/* + * entity_addr -- network address + */ +struct ceph_entity_addr { + __le32 erank; /* entity's rank in process */ + __le32 nonce; /* unique id for process (e.g. pid) */ + struct sockaddr_storage in_addr; +} __attribute__ ((packed)); + +static inline bool ceph_entity_addr_is_local(const struct ceph_entity_addr *a, + const struct ceph_entity_addr *b) +{ + return a->nonce == b->nonce && + memcmp(&a->in_addr, &b->in_addr, sizeof(a->in_addr)) == 0; +} + +static inline bool ceph_entity_addr_equal(const struct ceph_entity_addr *a, + const struct ceph_entity_addr *b) +{ + return memcmp(a, b, sizeof(*a)) == 0; +} + +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 */ + + +/* + * connection negotiation + */ +struct ceph_msg_connect { + __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; + __u8 flags; /* CEPH_MSG_CONNECT_* */ +} __attribute__ ((packed)); + +struct ceph_msg_connect_reply { + __u8 tag; + __le32 global_seq; + __le32 connect_seq; + __le32 protocol_version; + __u8 flags; +} __attribute__ ((packed)); + +#define CEPH_MSG_CONNECT_LOSSY 1 /* messages i send may be safely dropped */ + + +/* + * message header + */ +struct ceph_msg_header { + __le64 seq; /* message seq# for this session */ + __le16 type; /* message type */ + __le16 priority; /* priority. higher value == higher priority */ + + __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 dst_erank; + __le32 crc; /* header crc32c */ +} __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 + */ +struct ceph_msg_footer { + __le32 front_crc, middle_crc, data_crc; + __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 */ + + +#endif -- cgit v1.2.3