Manual Pages for UNIX Operating System command usage for man snmp_sess_close

Net-SNMP                                         SNMP_SESS_API(3)



NAME
     snmp_sess_init,      snmp_sess_open,      snmp_sess_session,
     snmp_sess_send, snmp_sess_async_send, snmp_sess_select_info,
     snmp_sess_read,     snmp_sess_timeout,      snmp_sess_close,
     snmp_sess_error - session functions

SYNOPSIS
     #include 

     void snmp_sess_init(struct snmp_session *session);

     void *snmp_sess_open(struct snmp_session *session);

     struct snmp_session *snmp_sess_session(void *handle);

     int snmp_sess_send(void *handle, struct snmp_pdu *pdu);

     int snmp_sess_async_send(void *handle,
                              struct snmp_pdu *pdu,
                              snmp_callback callback,
                              void *callbackData);

     int snmp_sess_select_info(void *handle,
                               int *numfds, fd_set *fdset,
                               struct timeval *timeout,
                               int *block);

     int snmp_sess_read(void *handle, fd_set *fdset);

     void snmp_sess_timeout(void *handle);

     int snmp_sess_close(void *handle);

     void snmp_sess_error(void *handle, int *pcliberr,
                         int *psnmperr, char **pperrstring);

DESCRIPTION
     These functions define a subset of the API that can be  used
     to  manage single SNMP sessions in a multi-threaded applica-
     tion.  Except for snmp_sess_session(), these  functions  are
     single session versions of the traditional SNMP library API.

     Note that these functions use an opaque pointer  (handle  in
     the  above  prototypes) to identify a single session in lieu
     of a session pointer (as in the traditional API).

     snmp_sess_init() prepares a struct snmp_session that sources
     transport  characteristics  and common information that will
     be used for a set of SNMP transactions.  After  this  struc-
     ture  is  passed  to snmp_sess_open() to create an SNMP ses-
     sion, the structure is no longer used.  Instead  the  opaque
     pointer  returned  by  snmp_sess_open()  is used to refer to



V5.4.1              Last change: 07 Mar 2002                    1






Net-SNMP                                         SNMP_SESS_API(3)



     that session henceforth.

     SNMP sessions that are created with snmp_sess_open() are not
     affected    by,    and    SHOULD    NOT    BE   USED   WITH,
     snmp_select_info(),    snmp_read(),    snmp_timeout()    nor
     snmp_close().   Rather  the  equivalent single session func-
     tions described here should be used.

     snmp_sess_init() and snmp_sess_open() each take as  input  a
     pointer  to  a  struct  snmp_session object.  This structure
     contains information for a set  of  transactions  that  will
     share        similar        transport       characteristics.
     snmp_sess_session() takes  the  opaque  session  handle  and
     returns a pointer to its associated struct snmp_session.

     snmp_sess_send() and snmp_sess_async_send() each take a  pdu
     parameter, which points to a struct snmp_pdu object contain-
     ing information that describes a transaction  that  will  be
     performed over an open session.

     Consult snmp_api.h for the definitions of these structures.

     snmp_sess_select_info(),        snmp_sess_read()         and
     snmp_sess_timeout()  provide an interface for the use of the
     select(2) system call so that SNMP transactions for a single
     session can occur asynchronously.

     snmp_sess_select_info() is passed the information that would
     have  been  passed to select(2) in the absence of SNMP.  For
     example, this might include file descriptors associated with
     the  main  loop of a graphical application. This information
     is modified so that SNMP will get the  service  it  requires
     from the call to select(2).  In this case, numfds, fdset and
     timeout correspond to the nfds, readfds  and  timeout  argu-
     ments to select(2) respectively.  The only exception is that
     timeout must ALWAYS point to an allocated (but perhaps unin-
     itialized)   struct  timeval  (it  cannot  be  NULL  as  for
     select(2)).  If timeout would  have  been  passed  as  NULL,
     block  is  instead  set  to  true, and timeout is treated as
     undefined.   This  same  rule  applies  upon   return   from
     snmp_select_info().

     After calling snmp_sess_select_info() , select(2) should  be
     called   with   the   returned   data.    When  it  returns,
     snmp_sess_read() should  then  be  called  with  the  fd_set
     returned from select(2).  This will read any input from this
     session's SNMP socket.  If select(2) times out (that is,  it
     returns  zero),  snmp_sess_timeout() should be called to see
     if a timeout has occurred on the SNMP session.

DIAGNOSTICS




V5.4.1              Last change: 07 Mar 2002                    2






Net-SNMP                                         SNMP_SESS_API(3)



     Error return status from snmp_sess_open()  is  indicated  by
     return   of  a  NULL  pointer.   Error  return  status  from
     snmp_sess_close() and snmp_sess_send()  is  indicated  by  a
     return value of 0.  A successful status will return 1.

     Further   information   can    be    obtained    by    using
     snmp_sess_error()  to  see  what type of error has occurred.
     This function returns  the  SNMP  snmp_errno  variable,  the
     value of the system errno variable, and a string interpreta-
     tion of both variables.  The string must be freed after  use
     by the caller.

     For errors returned by snmp_sess_open(), use the correspond-
     ing function snmp_error() instead of snmp_sess_error().

     Consult snmp_api.h for the  complete  set  of  SNMP  library
     error  values.   The SNMP library error value snmperr can be
     one of the following values:

       SNMPERR_GENERR           A generic error occurred.

       SNMPERR_BAD_LOCPORT      The local port was bad because it
                                had  already  been  allocated  or
                                permission was denied.

       SNMPERR_BAD_ADDRESS      The host name  or  address  given
                                was not useable.

       SNMPERR_BAD_SESSION      The  specified  session  was  not
                                open.

       SNMPERR_TOO_LONG

       SNMPERR_NO_SOCKET

       SNMPERR_V2_IN_V1

       SNMPERR_V1_IN_V2

       SNMPERR_BAD_REPEATERS

       SNMPERR_BAD_REPETITIONS

       SNMPERR_BAD_ASN1_BUILD

       SNMPERR_BAD_SENDTO

       SNMPERR_BAD_RCVFROM

       SNMPERR_BAD_PARSE

       SNMPERR_BAD_VERSION



V5.4.1              Last change: 07 Mar 2002                    3






Net-SNMP                                         SNMP_SESS_API(3)



       SNMPERR_BAD_COMMUNITY

       SNMPERR_NOAUTH_DESPRIV

       SNMPERR_ABORT

       SNMPERR_UNKNOWN_PDU

       SNMPERR_TIMEOUT

SEE ALSO
     select(2), snmp_api(3), snmp_api.h

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     box; cbp-1 | cbp-1 l | l .  ATTRIBUTE TYPE ATTRIBUTE VALUE =
     Availability   system/management/snmp/net-snmp  =  Interface
     Stability Volatile

NOTES
     Source for net-snmp is available on http://opensolaris.org.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     _______________________________________________________
    |   ATTRIBUTE TYPE   |          ATTRIBUTE VALUE        |
    |____________________|__________________________________|_
    | Availability       |  system/management/snmp/net-snmp|
    |____________________|__________________________________|_
    | Interface Stability|  Volatile                       |
    |____________________|_________________________________|

NOTES
     Source for net-snmp is available on http://opensolaris.org.

















V5.4.1              Last change: 07 Mar 2002                    4