I am attemting to use snmp to query a network printer for its status and its
appears that application built using the snmp libraries provided with the
TCP/IP development package grows in terms of memory usage.
I downloaded the snmpv1 sample from the contributed section and I modifed
the snmpget.c to loop continuly getting the stats and it too shows a memory
leak.
Can someone for QSSL please investigate to confirm or deny this. Thanks.
I start the modified snmpget as follows:
snmpget printerIP public
host.hrDevice.hrDeviceTable.hrDeviceEntry.hrDeviceStatus.1
host.hrDevice.hrPrinterTable.hrPrinterEntry.hrPrinterStatus.1
host.hrDevice.hrPrinterTable.hrPrinterEntry.hrPrinterDetectedErrorState.1
Here is the modified version of snmpget.c
/*
- snmpget.c - send snmp GET requests to a network entity.
/
/**********************************************************
Copyright 1988, 1989 by Carnegie Mellon University
All Rights Reserved
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of CMU not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
CMU DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
CMU BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
******************************************************************/
#include <sys/types.h>
#include <netinet/in.h>
#include <stdio.h>
#include <snmp/asn1.h>
#include <snmp/snmp.h>
#include <snmp/snmp_impl.h>
#include <snmp/asn1.h>
#include <snmp/snmp_api.h>
#include <snmp/snmp_client.h>
extern int errno;
int snmp_dump_packet = 0;
main(argc, argv)
int argc;
char *argv[];
{
struct snmp_session session, *ss;
struct snmp_pdu *pdu, *response;
struct variable_list *vars;
int arg;
char *gateway = NULL;
char *community = NULL;
int count, current_name = 0;
char *names[128];
oid name[MAX_NAME_LEN];
int name_length;
int status;
init_mib();
/*
- usage: snmpget gateway-name community-name
*/
for(arg = 1; arg < argc; arg++){
if (argv[arg][0] == ‘-’){
switch(argv[arg][1]){
case ‘d’:
snmp_dump_packet++;
break;
default:
printf(“invalid option: -%c\n”, argv[arg][1]);
break;
}
continue;
}
if (gateway == NULL){
gateway = argv[arg];
} else if (community == NULL){
community = argv[arg];
} else {
names[current_name++] = argv[arg];
}
}
if (!(gateway && community && current_name > 0)){
printf(“usage: snmpget gateway-name community-name object-identifier
[object-identifier …]\n”);
exit(1);
}
bzero((char *)&session, sizeof(struct snmp_session));
session.peername = gateway;
session.community = (u_char *)community;
session.community_len = strlen((char *)community);
session.retries = SNMP_DEFAULT_RETRIES;
session.timeout = SNMP_DEFAULT_TIMEOUT;
session.authenticator = NULL;
snmp_synch_setup(&session);
ss = snmp_open(&session);
if (ss == NULL){
printf(“Couldn’t open snmp\n”);
exit(-1);
}
while( 1 )
{
pdu = snmp_pdu_create(GET_REQ_MSG);
for(count = 0; count < current_name; count++){
name_length = MAX_NAME_LEN;
if (!read_objid(names[count], name, &name_length)){
printf(“Invalid object identifier: %s\n”, names[count]);
}
snmp_add_null_var(pdu, name, name_length);
}
status = snmp_synch_response(ss, pdu, &response);
if (status == STAT_SUCCESS){
if (response->errstat == SNMP_ERR_NOERROR){
for(vars = response->variables; vars; vars = vars->next_variable)
print_variable(vars->name, vars->name_length, vars);
} else {
printf(“Error in packet.\nReason: %s\n”,
snmp_errstring(response->errstat));
if (response->errstat == SNMP_ERR_NOSUCHNAME){
printf(“This name doesn’t exist: “);
for(count = 1, vars = response->variables; vars && count !=
response->errindex;
vars = vars->next_variable, count++)
;
if (vars)
print_objid(vars->name, vars->name_length);
printf(”\n”);
}
}
// pdu should be freed by snmp_synch_response on success
// free the response
if (response)
snmp_free_pdu(response);
} else if (status == STAT_TIMEOUT){
printf(“No Response from %s\n”, gateway);
// pdu should be freed by snmp_synch_response on success
// but this is NOT success so free the pdu
// free the response
if( pdu )
snmp_free_pdu( pdu );
if (response)
snmp_free_pdu(response);
} else { /* status == STAT_ERROR */
printf(“An error occurred, Quitting\n”);
exit( EXIT_FAILURE );
}
sleep( 1 );
}
snmp_close(ss);
}