Bug 1086925

Summary:	snmpd does not report error when clientaddr <ip>:<port> cannot bind to the specified port
Product:	Red Hat Enterprise Linux 7	Reporter:	Dalibor Pospíšil <dapospis>
Component:	net-snmp	Assignee:	Jan Safranek <jsafrane>
Status:	CLOSED ERRATA	QA Contact:	Dalibor Pospíšil <dapospis>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	7.0	CC:	dapospis, jsafrane, ksrot, lmiksik
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	Snapshot 4	Doc Type:	Bug Fix
Doc Text:	Cause: In one of the previous Net-SNMP updates we extended 'clientaddr' and 'clientaddrUsesPort' configuration options to allow system administrators to set specific port for outgoing SNMP requests. When this port number was not usable, for example it was already used, SNMP tools and daemons did not report any error and used random port for outgoing requests. Consequence: SNMP requests were sent from unexpected ports, while the system administrator did not know about it. Fix: Report an error that requested port cannot be used. Result: System admin knows that something is wrong.	Story Points:	---
Clone Of:	886468	Environment:
Last Closed:	2015-03-05 08:38:26 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	840861, 886468, 1877375
Bug Blocks:

Description Dalibor Pospíšil 2014-04-11 20:31:35 UTC

+++ This bug was initially created as a clone of Bug #886468 +++

+++ This bug was initially created as a clone of Bug #840861 +++

Description of problem:
Having following /etc/snmp/snmpd.conf file, if snmpd fails to bind the specified clientaddr port, it quietly uses random port instead. It should at least report some error to system log.

rocommunity public
[snmp] clientaddrUsesPort yes
[snmp] clientaddr 127.0.0.1:30000
trapsink localhost public

Version-Release number of selected component (if applicable):
net-snmp-5.7.2-18.el7

How reproducible:
always

Steps to Reproduce:
1. vi /etc/snmp/snmpd.conf
2. nc -ul localhost 30000 (or have SELinux in enforcing mode)
3. service snmpd start
  
Actual results:
- traps are sent from random port and not from port 30000, which is taken by 'nc'
- system log is empty

Expected results:
- system log should show an error

Comment 7 errata-xmlrpc 2015-03-05 08:38:26 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-0607.html