snmp.xs

ucd-snmp源代码

   char		*label;
   char		*iid;
   bulktbl	*expect = NULL;
   int		old_numeric;
   int		old_printfull;
   int		getlabel_flag;
   int		type;
   int		pix;
   int		len;
   int		i;
   AV		*varbind;
   SV		*rv;
   SV		*sv_timestamp = NULL;
   SV **sess_ptr_sv = hv_fetch((HV*)SvRV(context->sess_ref), "SessPtr", 7, 1);
   struct snmp_session *ss = (SnmpSession *)SvIV((SV*)SvRV(*sess_ptr_sv));
   SV **err_str_svp = hv_fetch((HV*)SvRV(context->sess_ref), "ErrorStr", 8, 1);
   SV **err_num_svp = hv_fetch((HV*)SvRV(context->sess_ref), "ErrorNum", 8, 1);
   SV **err_ind_svp = hv_fetch((HV*)SvRV(context->sess_ref), "ErrorInd", 8, 1);

   DBPRT(3, (DBOUT "bulkwalk: sess_ref = 0x%p, sess_ptr_sv = 0x%p, ss = 0x%p\n",
					    context->sess_ref, sess_ptr_sv, ss));

   if (SvIV(*hv_fetch((HV*)SvRV(context->sess_ref),"TimeStamp", 9, 1)))
      sv_timestamp = newSViv((IV)time(NULL));

   /* Set up for numeric OID's, if necessary.  Save the old values
   ** so that they can be restored when we finish -- these are
   ** library-wide globals, and have to be set/restored for each
   ** session.
   */
   old_numeric   = ds_get_boolean(DS_LIBRARY_ID, DS_LIB_PRINT_NUMERIC_OIDS);
   old_printfull = ds_get_boolean(DS_LIBRARY_ID, DS_LIB_PRINT_FULL_OID);
   if (context->getlabel_f & USE_NUMERIC_OIDS) {
      DBPRT(2,( "Using numeric oid's\n"));
      ds_set_boolean(DS_LIBRARY_ID, DS_LIB_PRINT_NUMERIC_OIDS, 1);
      ds_set_boolean(DS_LIBRARY_ID, DS_LIB_PRINT_FULL_OID, 1);
   }

   /* Parse through the list of variables returned, adding each return to
   ** the appropriate array (as a VarBind).  Also keep track of which
   ** repeated OID we're expecting to see, and check if that tree walk has
   ** been completed (i.e. we've walked past the root of our request).  If
   ** so, mark the request complete so that we don't send it again in any
   ** subsequent request packets.
   */
   if (context->pkts_exch == 1)
      context->reqbase = context->req_oids;	/* Request with non-repeaters */
   else
      context->reqbase = context->repbase;	/* Request only repeater vars */

   /* Note the first variable we expect to see.  Should be reqbase. */
   expect = context->reqbase;

   for (vars = pdu->variables, pix = 0;
	vars != NULL;
	vars = vars->next_variable, pix ++)
   {

      /* If no outstanding requests remain, we're done.  This works, but it
      ** causes the reported total variable count to be wrong (since the
      ** remaining vars on the last packet are not counted).  In practice
      ** this is probably worth the win, but for debugging it's not.
      */
      if (context->req_remain == 0) {
	 DBPRT(2,( "No outstanding requests remain.  Terminating processing.\n"));
	 while (vars) {
	    pix ++;
	    vars = vars->next_variable;
	 }
	 break;
      }

      /* Determine which OID we expect to see next.  We assert that the OID's
      ** must be returned in the expected order.  The first nreq_oids returns
      ** should match the req_oids array, after that, we must cycle through
      ** the repeaters in order.  Non-repeaters are not included in later
      ** packets, so cannot have the "ignore" flag set.
      */

      if (context->oid_saved < context->non_reps) {
	 assert(context->pkts_exch == 1);

	 expect = context->reqbase ++;
	 assert(expect->norepeat);

      } else {
	 /* Must be a repeater.  Look for the first one that is not being
	 ** ignored.  Make sure we don't loop around to where we started.
	 ** If we get here but everything is being ignored, there's a problem.
	 **
	 ** Note that we *do* accept completed but not ignored OID's -- these
	 ** are OID's for trees that have been completed sometime in this
	 ** response, but must be looked at to maintain ordering.
	 */

	 if (pix == 0) {
	    /* Special case code for no non-repeater case.  This
	    ** is necessary because expect normally points to the
	    ** last non-repeater upon entry to this code (so the
	    ** '++expect' below increments it into the repeaters
	    ** section of the req_oids[] array).
	    ** If there are no non-repeaters, the expect pointer
	    ** is never initialized.  This addresses this problem.
	    */
	    expect = context->reqbase;

	 } else {

	    /* Find the repeater OID we expect to see.  Ignore any
	    ** OID's marked 'ignore' -- these have been completed
	    ** and were not requested in this iteration.
	    */
	    for (i = 0; i < context->repeaters; i++) {

	       /* Loop around to first repeater if we hit the end. */
	       if (++ expect == &context->req_oids[context->nreq_oids])
		  expect = context->reqbase = context->repbase;

	       /* Stop if this OID is not being ignored. */
	       if (!expect->ignore)
		  break;
	    }

	    /* Make sure we did find an expected OID. */
	    assert(i <= context->repeaters);
	 }
      }

      DBPRT(2, (DBOUT "Var %03d request %s\n", pix, sprint_objid(_debugx,
					     expect->req_oid, expect->req_len)));

      /* Did we receive an error condition for this variable?
      ** If it's a repeated variable, mark it as complete and
      ** fall through to the block below.
      */
      if ((vars->type == SNMP_ENDOFMIBVIEW) ||
	  (vars->type == SNMP_NOSUCHOBJECT) ||
	  (vars->type == SNMP_NOSUCHINSTANCE))
      {
	 DBPRT(2,( "error type %d\n", (int)vars->type));

	 /* ENDOFMIBVIEW should be okay for a repeater - just walked off the
	 ** end of the tree.  Mark the request as complete, and go on to the
	 ** next one.
	 */
	 if ((context->oid_saved >= context->non_reps) &&
	     (vars->type == SNMP_ENDOFMIBVIEW))
	 {
	    expect->complete = 1;
	    DBPRT(2, (DBOUT "Ran out of tree for oid %s\n",
			   sprint_objid(_debugx, vars->name,vars->name_length)));

	    context->req_remain --;

	    /* Go on to the next variable. */
	    continue;

	 }
	 sv_setpv(*err_str_svp,
			      (char*)snmp_api_errstring(SNMPERR_UNKNOWN_OBJID));
	 sv_setiv(*err_num_svp, SNMPERR_UNKNOWN_OBJID);
	 sv_setiv(*err_ind_svp, pix);
	 goto err;
      }

      /* If this is not the first packet, skip any duplicated OID values, if
      ** present.  These should be the seed values copied from the last OID's
      ** of the previous packet.  In practice we don't see this, but it is
      ** easy enough to do, and will avoid confusion for the caller from mis-
      ** behaving agents (badly misbehaving... ;^).
      */
      if ((context->pkts_exch > 1) && (pix < context->repeaters)) {
	 if (__oid_cmp(vars->name, vars->name_length,
				   context->reqbase[pix].last_oid,
				   context->reqbase[pix].last_len) == 0)
	 {
	    DBPRT(2, (DBOUT "Ignoring repeat oid: %s\n",
			sprint_objid(_debugx, vars->name,vars->name_length)));

	    continue;
	 }
      }

      context->oid_total ++;	/* Count each variable received. */

      /* If this is a non-repeater, handle it.  Otherwise, if it is a
      ** repeater, has the walk wandered off of the requested tree?  If so,
      ** this request is complete, so mark it as such.  Ignore any other
      ** variables in a completed request.  In order to maintain the correct
      ** ordering of which variables we expect to see in this packet, we must
      ** not set the ignore flags immediately.  It is done in bulkwalk_done().
      ** XXX Can we use 'expect' instead of 'context->req_oids[pix]'?
      */
      if (context->oid_saved < context->non_reps) {
	 DBPRT(2, (DBOUT "   expected var %s (nonrepeater %d/%d)\n",
		     sprint_objid(_debugx, context->req_oids[pix].req_oid,
					   context->req_oids[pix].req_len),
		     pix, context->non_reps));
	 DBPRT(2, (DBOUT "   received var %s\n",
		     sprint_objid(_debugx, vars->name, vars->name_length)));

	 /* This non-repeater has now been seen, so mark the sub-tree as
	 ** completed.  Note that this may not be the same oid as requested,
	 ** since non-repeaters act like GETNEXT requests, not GET's. <sigh>
	 */
	 context->req_oids[pix].complete = 1;
	 context->req_remain --;

      } else {		/* Must be a repeater variable. */

	 DBPRT(2, (DBOUT "   received oid %s\n",
	       sprint_objid(_debugx, vars->name, vars->name_length)));

	 /* Are we already done with this tree?  If so, just ignore this
	 ** variable and move on to the next expected variable.
	 */
	 if (expect->complete) {
	    DBPRT(2,( "      this branch is complete - ignoring.\n"));
	    continue;
	 }

	 /* If the base oid of this variable doesn't match the expected oid,
	 ** assume that we've walked past the end of the subtree.  Set this
	 ** subtree to be completed, and go on to the next variable.
	 */
	 if ((vars->name_length < expect->req_len) ||
	     (memcmp(vars->name, expect->req_oid, expect->req_len*sizeof(oid))))
	 {
	    DBPRT(2,( "      walked off branch - marking subtree as complete.\n"));
	    expect->complete = 1;
	    context->req_remain --;
	    continue;
	 }

	 /* Still interested in the tree -- we need to keep track of the
	 ** last-seen value in case we need to send an additional request
	 ** packet.
	 */
	 (void)memcpy(expect->last_oid, vars->name,
					     vars->name_length * sizeof(oid));
	 expect->last_len = vars->name_length;

      }

      /* Create a new Varbind and populate it with the parsed information
      ** returned by the agent.  This Varbind is then pushed onto the arrays
      ** maintained for each request OID in the context.  These varbinds are
      ** collected into a return array by bulkwalk_finish().
      */
      varbind = (AV*) newAV();
      if (varbind == NULL) {
	 sv_setpv(*err_str_svp, "newAV() failed: ");
	 sv_catpv(*err_str_svp, (char*)strerror(errno));
	 sv_setiv(*err_num_svp, SNMPERR_MALLOC);
	 goto err;
      }

      *str_buf = '.';
      *(str_buf+1) = '\0';
      tp = get_symbol(vars->name,vars->name_length, get_tree_head(), str_buf+1);

      getlabel_flag = context->getlabel_f;

      if (__is_leaf(tp)) {
	 type = tp->type;
      } else {
	 getlabel_flag |= NON_LEAF_NAME;
	 type = __translate_asn_type(vars->type);
      }
      __get_label_iid(str_buf, &label, &iid, getlabel_flag);

      DBPRT(2,( "       save var %s.%s = ", label, iid));

      av_store(varbind, VARBIND_TAG_F, newSVpv(label, strlen(label)));
      av_store(varbind, VARBIND_IID_F, newSVpv(iid, strlen(iid)));

      __get_type_str(type, type_str);
      av_store(varbind, VARBIND_TYPE_F, newSVpv(type_str, strlen(type_str)));

      len=__sprint_value(str_buf, vars, tp, type, context->sprintval_f);
      av_store(varbind, VARBIND_VAL_F, newSVpv((char*)str_buf, len));

      str_buf[len] = '\0';
      DBPRT(3,( "'%s' (%s)\n", str_buf, type_str));

      /* If necessary, store a timestamp as the semi-documented 5th element. */
      if (sv_timestamp)
	  av_store(varbind, VARBIND_TIME_F, SvREFCNT_inc(sv_timestamp));

      /* Push ref to the varbind onto the list of vars for OID. */
      rv = newRV_noinc((SV *)varbind);
      sv_bless(rv, gv_stashpv("SNMP::Varbind", 0));
      av_push(expect->vars, rv);

      context->oid_saved ++;	/* Count this as a saved variable. */

   } /* next variable in response packet */

   DBPRT(1, (DBOUT "-- pkt %d saw %d vars, total %d (%d saved)\n", context->pkts_exch,
			   pix, context->oid_total, context->oid_saved));

   /* We assert that all non-repeaters must be returned in
   ** the initial response (they are not repeated in additional
   ** packets, so would be dropped).  If nonrepeaters still
   ** exist, consider it a fatal error.
   */
   if ((context->pkts_exch == 1) && (context->oid_saved < context->non_reps)) {
      /* Re-use space from the value string for error message. */
      sprintf(str_buf, "%d non-repeaters went unanswered", context->non_reps);
      sv_setpv(*err_str_svp, str_buf);
      sv_setiv(*err_num_svp, SNMPERR_GENERR);
      sv_setiv(*err_num_svp, context->oid_saved);
      goto err;
   }

   /* Reset the library's behavior for numeric/symbolic OID's. */
   if (context->getlabel_f & USE_NUMERIC_OIDS) {
      ds_set_boolean(DS_LIBRARY_ID, DS_LIB_PRINT_NUMERIC_OIDS, old_numeric);
      ds_set_boolean(DS_LIBRARY_ID, DS_LIB_PRINT_FULL_OID, old_printfull);
   }

   return pix;

   err:
   if (pdu)
      snmp_free_pdu(pdu);
   return -1;

}

/* Once the bulkwalk has completed, extend the stack and push references to
** each of the arrays of SNMP::Varbind's onto the stack.  Return the number
** of arrays pushed on the stack.  The caller should return to Perl, or call
** the Perl callback function.
**
** Note that this function free()'s the walk_context and request bulktbl's.
*/
static int
_bulkwalk_finish(walk_context *context, int okay)
{
   int		npushed = 0;
   int		i;
   int		async = 0;
   bulktbl	*bt_entry;
   AV		*ary = NULL;
   SV		*rv;
   SV		*perl_cb;

   SV **err_str_svp = hv_fetch((HV*)SvRV(context->sess_ref), "ErrorStr", 8, 1);
   SV **err_num_svp = hv_fetch((HV*)SvRV(context->sess_ref), "ErrorNum", 8, 1);

   dXSARGS;

   async = SvTRUE(context->perl_cb);

   /* Successfully completed the bulkwalk.  For synchronous calls, push each
   ** of the request value arrays onto the stack, and return the number of
   ** items pushed onto the stack.  For async, create a new array and push
   ** the references onto it.  The array is then passed to the Perl callback.
   */
   if (!async)
      SP -= items;

   DBPRT(1, (DBOUT "Bulwalk %s (saved %d/%d), ", okay ? "completed" : "had error",
					context->oid_saved, context->oid_total));

   if (okay) {
       DBPRT(1, (DBOUT "%s %d varbind refs %s\n",
				async ? "pass ref to array of" : "return",
				context->nreq_oids,
				async ? "to callback" : "on stack to caller"));

       /* Create the array to hold the responses for the asynchronous callback,
       ** or pre-extend the stack enough to hold responses for synch return.
       */
       if (async) {
	   ary = (AV *)newAV();
	  if (ary == NULL) {
	     sv_setpv(*err_str_svp, "newAV(): ");
	     sv_catpv(*err_str_svp, (char *)strerror(errno));
	     sv_setiv(*err_num_svp, errno);
	  }

	  /* NULL ary pointer is okay -- we'll handle it below... */

       } else {
	   EXTEND(sp, context->nreq_oids);

       }

       /* Push a reference to each array of varbinds onto the stack, in
       ** the order requested.  Note that these arrays may be empty.
       */
       for (i = 0; i < context->nreq_oids; i++) {
	  bt_entry = &context->req_oids[i];

	  DBPRT(2, (DBOUT "  %sreq #%d (%s) => %d var%s\n",
		 bt_entry->complete ? "" : "incomplete ", i,
		 sprint_objid(_debugx, bt_entry->req_oid, bt_entry->req_len),
		 (int)av_len(bt_entry->vars) + 1,
		 (int)av_len(bt_entry->vars) > 0 ? "s" : ""));

	  if (async && ary == NULL) {
	     DBPRT(2,( "    [dropped due to newAV() failure]\n"));
	     continue;
	  }

	  /* Get a reference to the varlist, and push it onto array or stack */
	  rv = newRV_noinc((SV *)bt_entry->vars);
	  sv_bless(rv, gv_stashpv("SNMP::VarList",0));

	  if (async)
	     av_push(ary, rv);
	  else
	     PUSHs(sv_2mortal((SV *)rv));

	  npushed ++;
       }

   } else {	/* Not okay -- push a single undef on the stack if not async */

      if (!async) {
	 XPUSHs(&sv_undef);
	 npushed = 1;
      }
   }

   /* XXX Future enhancement -- make statistics (pkts exchanged, vars
   ** saved vs. received, total time, etc) available to caller so they
   ** can adjust their request parameters and/or re-order requests.
   */

   PUTBACK;

   if (async) {
       /* Asynchronous callback.  Push the caller's arglist onto the stack,
       ** and follow it with the contents of the array (or undef if newAV()
       ** failed