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epics-base/src/ca/caProto.h
Michael Abbott a0c0c55347 Client side support for automatic resizing arrays. 
In this commit the channel access client is modified to allow a zero
size request in a caget or camonitor call.  This is passed through to
the corresponding CA_PROTO_READ_NOTIFY or CA_PROTO_EVENT__ADD message,
but only if the minor version of the protocol is >=13.

This commit also adds a new protocol test, CA_V413(), which detects a
server which claims to understand the new zero length request.

Finally, this commit prepares for a subtle change in the CA protocol.
A request for a zero length subscription or data request, which will
only be made for protocol version 4.13 and above, is interpreted as a
request for autosized data, where the intrinsic dynamic length of the
requested waveform should be returned.

With the synchronous ca_array_get() call there is no mechanism available
to pass back the size of the retrieved data if it is different from
the requested count, so the simplest thing is to ensure we don't
request autosizing data through this api.
2010-08-11 16:22:54 -05:00

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/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
* National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
* Operator of Los Alamos National Laboratory.
* EPICS BASE Versions 3.13.7
* and higher are distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
\*************************************************************************/
/*
*
* Author Jeffrey O. Hill
* johill@lanl.gov
* 505 665 1831
*/
#ifndef __CAPROTO__
#define __CAPROTO__
#define capStrOf(A) #A
#define capStrOfX(A) capStrOf ( A )
/*
* CA protocol revision
* TCP/UDP port number (bumped each major protocol change)
*/
#define CA_MAJOR_PROTOCOL_REVISION 4
#define CA_VERSION_STRING( MINOR_REVISION ) \
( capStrOfX ( CA_MAJOR_PROTOCOL_REVISION ) "." capStrOfX ( MINOR_REVISION ) )
#define CA_UKN_MINOR_VERSION 0u /* unknown minor version */
#if CA_MAJOR_PROTOCOL_REVISION == 4u
# define CA_V41(MINOR) ((MINOR)>=1u)
# define CA_V42(MINOR) ((MINOR)>=2u)
# define CA_V43(MINOR) ((MINOR)>=3u)
# define CA_V44(MINOR) ((MINOR)>=4u)
# define CA_V45(MINOR) ((MINOR)>=5u)
# define CA_V46(MINOR) ((MINOR)>=6u)
# define CA_V47(MINOR) ((MINOR)>=7u)
# define CA_V48(MINOR) ((MINOR)>=8u)
# define CA_V49(MINOR) ((MINOR)>=9u) /* large arrays, dispatch priorities */
# define CA_V410(MINOR) ((MINOR)>=10u) /* beacon counter */
# define CA_V411(MINOR) ((MINOR)>=11u) /* sequence numbers in UDP version command */
# define CA_V412(MINOR) ((MINOR)>=12u) /* TCP-based search requests */
# define CA_V413(MINOR) ((MINOR)>=13u) /* Allow zero length in requests. */
#elif CA_MAJOR_PROTOCOL_REVISION > 4u
# define CA_V41(MINOR) ( 1u )
# define CA_V42(MINOR) ( 1u )
# define CA_V43(MINOR) ( 1u )
# define CA_V44(MINOR) ( 1u )
# define CA_V45(MINOR) ( 1u )
# define CA_V46(MINOR) ( 1u )
# define CA_V47(MINOR) ( 1u )
# define CA_V48(MINOR) ( 1u )
# define CA_V49(MINOR) ( 1u )
# define CA_V410(MINOR) ( 1u )
# define CA_V411(MINOR) ( 1u )
# define CA_V412(MINOR) ( 1u )
# define CA_V413(MINOR) ( 1u )
#else
# define CA_V41(MINOR) ( 0u )
# define CA_V42(MINOR) ( 0u )
# define CA_V43(MINOR) ( 0u )
# define CA_V44(MINOR) ( 0u )
# define CA_V45(MINOR) ( 0u )
# define CA_V46(MINOR) ( 0u )
# define CA_V47(MINOR) ( 0u )
# define CA_V48(MINOR) ( 0u )
# define CA_V49(MINOR) ( 0u )
# define CA_V410(MINOR) ( 0u )
# define CA_V411(MINOR) ( 0u )
# define CA_V412(MINOR) ( 0u )
# define CA_V413(MINOR) ( 0u )
#endif
/*
* These port numbers are only used if the CA repeater and
* CA server port numbers cant be obtained from the EPICS
* environment variables "EPICS_CA_REPEATER_PORT" and
* "EPICS_CA_SERVER_PORT"
*/
#define CA_PORT_BASE IPPORT_USERRESERVED + 56U
#define CA_SERVER_PORT (CA_PORT_BASE+CA_MAJOR_PROTOCOL_REVISION*2u)
#define CA_REPEATER_PORT (CA_PORT_BASE+CA_MAJOR_PROTOCOL_REVISION*2u+1u)
/*
* 1500 (max of ethernet and 802.{2,3} MTU) - 20(IP) - 8(UDP)
* (the MTU of Ethernet is currently independent of its speed varient)
*/
#define ETHERNET_MAX_UDP ( 1500u - 20u - 8u )
#define MAX_UDP_RECV ( 0xffff + 16u ) /* allow large frames to be received in the future */
#define MAX_UDP_SEND 1024u /* original MAX_UDP */
#define MAX_TCP ( 1024 * 16u ) /* so waveforms fit */
#define MAX_MSG_SIZE ( MAX_TCP ) /* the larger of tcp and udp max */
#define CA_PROTO_PRIORITY_MIN 0u
#define CA_PROTO_PRIORITY_MAX 99u
/*
* architecture independent types
*
* (so far this works on all archs we have ported to)
*/
typedef unsigned char ca_uint8_t;
typedef unsigned short ca_uint16_t;
typedef unsigned int ca_uint32_t;
typedef float ca_float32_t;
typedef ca_uint32_t caResId;
#define ca_uint32_max 0xffffffff
/* values for m_cmmd */
#define CA_PROTO_VERSION 0u /* set minor version and priority (used to be NOOP cmd) */
#define CA_PROTO_EVENT_ADD 1u /* add an event */
#define CA_PROTO_EVENT_CANCEL 2u /* cancel an event */
#define CA_PROTO_READ 3u /* read and return a channel value*/
#define CA_PROTO_WRITE 4u /* write a channel value */
#define CA_PROTO_SNAPSHOT 5u /* snapshot of the system */
#define CA_PROTO_SEARCH 6u /* IOC channel search */
#define CA_PROTO_BUILD 7u /* build - obsolete */
#define CA_PROTO_EVENTS_OFF 8u /* flow control */
#define CA_PROTO_EVENTS_ON 9u /* flow control */
#define CA_PROTO_READ_SYNC 10u /* purge old reads */
#define CA_PROTO_ERROR 11u /* an operation failed */
#define CA_PROTO_CLEAR_CHANNEL 12u /* free chan resources */
#define CA_PROTO_RSRV_IS_UP 13u /* CA server has joined the net */
#define CA_PROTO_NOT_FOUND 14u /* channel not found */
#define CA_PROTO_READ_NOTIFY 15u /* add a one shot event */
#define CA_PROTO_READ_BUILD 16u /* read and build - obsolete */
#define REPEATER_CONFIRM 17u /* registration confirmation */
#define CA_PROTO_CREATE_CHAN 18u /* client creates channel in server */
#define CA_PROTO_WRITE_NOTIFY 19u /* notify after write chan value */
#define CA_PROTO_CLIENT_NAME 20u /* CA V4.1 identify client */
#define CA_PROTO_HOST_NAME 21u /* CA V4.1 identify client */
#define CA_PROTO_ACCESS_RIGHTS 22u /* CA V4.2 asynch access rights chg */
#define CA_PROTO_ECHO 23u /* CA V4.3 connection verify */
#define REPEATER_REGISTER 24u /* register for repeater fan out */
#define CA_PROTO_SIGNAL 25u /* knock the server out of select */
#define CA_PROTO_CREATE_CH_FAIL 26u /* unable to create chan resource in server */
#define CA_PROTO_SERVER_DISCONN 27u /* server deletes PV (or channel) */
#define CA_PROTO_LAST_CMMD CA_PROTO_SERVER_DISCONN
/*
* for use with search and not_found (if search fails and
* its not a broadcast tell the client to look elesewhere)
*/
#define DOREPLY 10u
#define DONTREPLY 5u
/*
* for use with the m_dataType field in UDP messages emitted by servers
*/
#define sequenceNoIsValid 1
/* size of object in bytes rounded up to nearest oct word */
#define OCT_ROUND(A) (((A)+7)/8)
#define OCT_SIZEOF(A) (OCT_ROUND(sizeof(A)))
/* size of object in bytes rounded up to nearest long word */
#define QUAD_ROUND(A) ((A)+3)/4)
#define QUAD_SIZEOF(A) (QUAD_ROUND(sizeof(A)))
/* size of object in bytes rounded up to nearest short word */
#define BI_ROUND(A) (((A)+1)/2)
#define BI_SIZEOF(A) (BI_ROUND(sizeof(A)))
/*
* For communicating access rights to the clients
*
* (placed in m_available hdr field of CA_PROTO_ACCESS_RIGHTS cmmd
*/
#define CA_PROTO_ACCESS_RIGHT_READ (1u<<0u)
#define CA_PROTO_ACCESS_RIGHT_WRITE (1u<<1u)
/*
* All structures passed in the protocol must have individual
* fields aligned on natural boundaries.
*
* NOTE: all structures declared in this file must have a
* byte count which is evenly divisible by 8 matching
* the largest atomic data type in db_access.h.
*/
#define CA_MESSAGE_ALIGN(A) (OCT_ROUND(A)<<3u)
/*
* the common part of each message sent/recv by the
* CA server.
*/
typedef struct ca_hdr {
ca_uint16_t m_cmmd; /* operation to be performed */
ca_uint16_t m_postsize; /* size of payload */
ca_uint16_t m_dataType; /* operation data type */
ca_uint16_t m_count; /* operation data count */
ca_uint32_t m_cid; /* channel identifier */
ca_uint32_t m_available; /* protocol stub dependent */
} caHdr;
/*
* for monitor (event) message extension
*/
struct mon_info {
ca_float32_t m_lval; /* low delta */
ca_float32_t m_hval; /* high delta */
ca_float32_t m_toval; /* period btween samples */
ca_uint16_t m_mask; /* event select mask */
ca_uint16_t m_pad; /* extend to 32 bits */
};
/*
* PV names greater than this length assumed to be invalid
*/
#define unreasonablePVNameSize 500u
#endif /* __CAPROTO__ */
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