NETMOD WG Clyde Wildes
Internet-Draft Cisco Systems
Intended status: Informational Agrahara Kiran Koushik
Expires: January 03, 2015 Brocade Communication Systems
July 03, 2014
SYSLOG YANG model
draft-wildes-netmod-syslog-model-01
Abstract
This document describes a data model for Syslog
protocol which is used to convey event notification messages.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on January 03, 2015.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Definitions and Acronyms . . . . . . . . . . . . . . . . 3
2. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
3. Design of the SYSLOG Model . . . . . . . . . . . . . . . . . 3
3.1. SYSLOG Module . . . . . . . . . . . . . . . . . . . . . . 4
4. SYSLOG YANG Models . . . . . . . . . . . . . . . . . . . . . 6
4.1. SYSLOG TYPES Module . . . . . . . . . . . . . . . . . . . 6
4.2. SYSLOG module . . . . . . . . . . . . . . . . . . . . . . 10
4.3. A SYSLOG Example . . . . . . . . . . . . . . . . . . . . 16
5. Implementation Status . . . . . . . . . . . . . . . . . . . . 17
6. Security Considerations . . . . . . . . . . . . . . . . . . . 17
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
9. Change log [RFC Editor: Please remove] . . . . . . . . . . . 18
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction
Operating systems, processes and applications generate messages
indicating their own status or the occurance of events. These
messages are useful for managing and/or debugging the network and its
services. The BSD Syslog protocol is a widely adopted protocol that
is used for transmission and processing of the messages.
Since each process, application and operating system was
written somewhat independently, there is little uniformity to the
content of Syslog messages. For this reason, no assumption is made
upon the formatting or contents of the messages. The protocol is
simply designed to transport these event messages. No
acknowledgement of the receipt is made.
Essentially, a Syslog process receives messages (from the kernel,
processes, applications or other Syslog processes) and processes
those. The processing involves logging to a local file, displaying on
console, user terminal, and/or relaying to syslog processes on other
machines. The processing is determined by the "facility" that
originated the message and the "severity" assigned to the message by
the facility.
We are using definitions of Syslog protocol from [RFC3164] in this
draft.
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1.1. Definitions and Acronyms
IP: Internet Protocol
IPv4: Internet Protocol version 4
IPv6: Internet Protocol version 6
UDP: User Datagram Protocol
VRF: Virtual Routing and Forwarding
2. Problem Statement
This document defines a YANG [RFC6020] configuration data model that
may be used to monitor and control one or more syslog processes running
on a system. YANG models can be used with network management
agents such as NETCONF [RFC6241] to install, manipulate, and delete
the configuration of network devices.
This module makes use of the YANG "feature" construct which allows
implementations to support only those Syslog features that lie
within their capabilities.
3. Design of the SYSLOG Model
The syslog model was designed by comparing various syslog features
implemented by various vendors' in different implementations.
This draft addresses the common leafs between all vendors and creates
a common model, which can be augmented with proprietary features, if
necessary. The base model is designed to be very simple for maximum
flexibility.
Syslog consists of message producers, a group level suppression filter,
and message distributors. The following digram shows syslog messages
flowing from a message producer, through the group level suppression
filter, and if passed by the group filter to message distributors where
further suppression filtering can take place.
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Message Producers
+-------------+ +-------------+ +-------------+ +-------------+
| Various | | OS | | | | Remote |
| Components | | Kernel | | Line Cards | | Servers |
+-------------+ +-------------+ +-------------+ +-------------+
+-------------+ +-------------+ +-------------+ +-------------+
| SNMP | | Interface | | Standby | | Syslog |
| Events | | Events | | Supervisor | | Itself |
+-------------+ +-------------+ +-------------+ +-------------+
| |
+----------------------------------------------------------------+
|
|
v
Group Level Suppression
+------------------------------+
| Filter by message facility |
| and message severity |
+------------------------------+
|
|
|
+-----+---------+----------------+-----------------+
| | | |
v v v v
Message Distributors
+-------------+ +-------------+ +-------------+ +-------------+
| | | | | User | | Remote |
| Console | | Log File(s) | | Terminals | | Servers |
+-------------+ +-------------+ +-------------+ +-------------+
The leaves in the base syslog model correspond to the group level
suppression filter and each message distributor:
- console
- log file(s)
- user terminals
- remote server(s).
Optional features are used to specified fields that are not present in
all vendor configurations.
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3.1. SYSLOG Module
module: ietf-syslog
+--rw syslog
+--rw global-logging
| +--rw logging-severities [facility]
| +--rw facility identityref
| +--rw severity? syslogtypes:Severity
+--rw console-logging
| +--rw (logging-level-scope)?
| +--:(all-facilities)
| | +--rw logging-severity? syslogtypes:Severity
| +--:(facility)
| +--rw logging-severities [facility]
| +--rw facility identityref
| +--rw severity? syslogtypes:Severity
+--rw file-logging
| +--rw file-name string
| +--rw file-size? uint32
| +--rw (logging-scope)?
| +--:(all-facilities)
| | +--rw logging-severity? syslogtypes:Severity
| +--:(facility)
| +--rw logging-severities [facility]
| +--rw facility identityref
| +--rw severity? syslogtypes:Severity
+--rw remote-logging
| +--rw remote-logging-destination [destination]
| +--rw destination string
| +--rw logging-severities [facility]
| | +--rw facility identityref
| | +--rw severity? syslogtypes:Severity
| +--rw source-interface? string
| +--rw vrf-name? string
+--rw terminal-logging
+--rw (user-scope)?
+--:(all-users)
| +--rw all-users
| +--rw (logging-scope)?
| +--:(all-facilities)
| | +--rw logging-severity? syslogtypes:Severity
| +--:(facility)
| +--rw logging-severities [facility]
| +--rw facility identityref
| +--rw severity? syslogtypes:Severity
+--:(per-user)
+--rw user-name [uname]
+--rw uname string
+--rw (logging-scope)?
+--:(all-facilities)
| +--rw logging-severity? syslogtypes:Severity
+--:(facility)
+--rw logging-severities [facility]
+--rw facility identityref
+--rw severity? syslogtypes:Severity
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4. SYSLOG YANG Models
4.1. SYSLOG-TYPES module
module ietf-syslog-types {
namespace "urn:ietf:params:xml:ns:yang:ietf-syslog-types";
prefix syslogtypes;
organization "IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
WG Chair: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>
WG Chair: Tom Nadeau
<mailto:tnadeau@brocade.com>
Editor: Clyde Wildes
<mailto:cwildes@cisco.com>
Editor: Agrahara Kiran Koushik
<mailto:kkoushik@brocade.com>";
description
"This module contains a collection of YANG type definitions for Syslog.";
revision 2014-06-03 {
description
"Version 1.0";
}
typedef Severity {
type enumeration {
enum "emergency" {
value 0;
description
"Emergency Level Msg";
}
enum "alert" {
value 1;
description
"Alert Level Msg";
}
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enum "critical" {
value 2;
description
"Critical Level Msg";
}
enum "error" {
value 3;
description
"Error Level Msg";
}
enum "warning" {
value 4;
description
"Warning Level Msg";
}
enum "notice" {
value 5;
description
"Notification Level Msg";
}
enum "info" {
value 6;
description
"Informational Level Msg";
}
enum "debug" {
value 7;
description
"Debugging Level Msg";
}
}
description
"The definitions for Syslog message severity.";
}
identity syslog-facility {
description
"The base identity to represent syslog facilities";
}
identity kern {
base syslog-facility;
}
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identity user {
base syslog-facility;
}
identity mail {
base syslog-facility;
}
identity daemon {
base syslog-facility;
}
identity auth {
base syslog-facility;
}
identity syslog {
base syslog-facility;
}
identity lpr {
base syslog-facility;
}
identity news {
base syslog-facility;
}
identity uucp {
base syslog-facility;
}
identity cron {
base syslog-facility;
}
identity authpriv {
base syslog-facility;
}
identity ftp {
base syslog-facility;
}
identity ntp {
base syslog-facility;
}
identity audit {
base syslog-facility;
}
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identity console {
base syslog-facility;
}
identity cron2 {
base syslog-facility;
}
identity local0 {
base syslog-facility;
}
identity local1 {
base syslog-facility;
}
identity local2 {
base syslog-facility;
}
identity local3 {
base syslog-facility;
}
identity local4 {
base syslog-facility;
}
identity local5 {
base syslog-facility;
}
identity local6 {
base syslog-facility;
}
identity local7 {
base syslog-facility;
}
}
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4.2. SYSLOG module
module ietf-syslog {
namespace "urn:ietf:params:xml:ns:yang:ietf-syslog";
prefix syslog;
import ietf-syslog-types {
prefix syslogtypes;
}
organization "IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
WG Chair: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>
WG Chair: Tom Nadeau
<mailto:tnadeau@brocade.com>
Editor: Clyde Wildes
<mailto:cwildes@cisco.com>
Editor: Agrahara Kiran Koushik
<mailto:kkoushik@brocade.com>";
description
"This module contains a collection of YANG definitions
for Syslog configuration.";
revision 2014-06-10 {
description
"Initial revision.";
}
feature global-logging {
description
"This feature represents the ability to adjust
log message severity per logging facility on the global level.";
}
feature console-facility-logging-config {
description
"This feature represents the ability to adjust
log message severity per logging facility for console logging.";
}
feature file-logging {
description
"This feature represents the ability to log
messages into a file.";
}
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feature file-facility-logging-config {
description
"This feature represents the ability to adjust
log message severity per logging facility for file logging.";
}
feature terminal-facility-logging-config {
description
"This feature represents the ability to adjust
log message severity per logging facility for terminal logging.";
}
feature terminal-facility-user-logging-config {
description
"This feature represents the ability to adjust
log message settings for individual terminal users.";
}
feature use-vrf {
description
"This feature allows logging of messages to a particular VRF.";
}
grouping facility-logging {
description
"This grouping defines a list of facility-severity pairs. Messages
from a facility in the list that have the corresponding specified
severity level or higher will be logged.";
list logging-severities {
description
"This list describes a collection of Syslog facilities.";
key "facility";
leaf facility {
type identityref {
base syslogtypes:syslog-facility;
}
description
"The leaf uniqueuely identifies a Syslog facility.";
}
leaf severity {
type syslogtypes:Severity;
description
"This leaf specifies the severity of Syslog messages
for this facility.";
}
}
}
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container syslog {
description
"This container describes the configuration parameters for Syslog.";
config true;
container global-logging {
if-feature global-logging;
description
"This container describes the configuration parameters for global
logging.";
uses facility-logging;
}
container console-logging {
description
"This container describes the configuration parameters for console
logging.";
choice logging-level-scope {
description
"This choice describes the option to specify all facilities or
a specific facility.";
case all-facilities {
description
"This case specifies all facilities.";
leaf logging-severity {
type syslogtypes:Severity;
description
"This leaf specifies the severity of Syslog messages
for all facilities.";
}
}
case facility {
description
"This case specifies a specific facility.";
if-feature console-facility-logging-config;
uses facility-logging;
}
}
}
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container file-logging {
if-feature file-logging;
description
"This container describes the configuration parameters for file
logging configuration.";
leaf file-name {
mandatory true;
type string;
description
"This leaf specifies the name of the log file.";
}
leaf file-size {
type uint32;
description
"This leaf specifies the log file size.";
}
choice logging-scope {
description
"This choice describes the option to specify all facilities or
a specific facility.";
case all-facilities {
description
"This case specifies all facilities.";
leaf logging-severity {
type syslogtypes:Severity;
description
"This leaf specifies the severity of Syslog messages
for all facilities.";
}
}
case facility {
description
"This case specifies a specific facility.";
if-feature file-facility-logging-config;
uses facility-logging;
}
}
}
container remote-logging {
description
"This container describes the configuration parameters for the remote
logging configuration.";
list remote-logging-destination {
description
"This list describes a collection of remote logging destinations.";
key "destination";
leaf destination {
type string;
description
"The leaf uniquely specifies the address of the remote host. One
of the following must be specified: an ipv4 address, an ipv6
address, or a host name.";
}
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uses facility-logging;
leaf source-interface {
description
"This leaf sets the source interface for the remote Syslog server.
Either the interface name or the interface IP address can be
specified.";
type string;
}
leaf vrf-name {
if-feature use-vrf;
type string;
description
"This leaf specifies the name of the virtual routing facility
(VRF).";
}
}
}
container terminal-logging {
description
"This container describes the configuration parameters for the terminal
logging configuration.";
choice user-scope {
description
"This choice describes the option to specify all users or a specific
user.";
case all-users {
description
"This case specifies all users.";
container all-users {
choice logging-scope {
description
"This choice describes the option to specify all facilities or
a specific facility.";
case all-facilities {
description
"This case specifies all facilities.";
leaf logging-severity {
type syslogtypes:Severity;
description
"This leaf specifies the severity of Syslog messages
for all facilities.";
}
}
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case facility {
description
"This case specifies a specific facility.";
if-feature terminal-facility-logging-config;
uses facility-logging;
}
}
}
}
case per-user {
description
"This case specifies a specific user.";
if-feature terminal-facility-user-logging-config;
list user-name {
description
"This list describes a collection of user names.";
key "uname";
leaf uname {
type string;
description
"This leaf uniquely describes a user name.";
}
choice logging-scope {
description
"This choice describes the option to specify all facilities or
a specific facility.";
case all-facilities {
description
"This case specifies all facilities.";
leaf logging-severity {
type syslogtypes:Severity;
description
"This leaf specifies the severity of Syslog messages
for all facilities.";
}
}
case facility {
description
"This case specifies a specific facility.";
if-feature terminal-facility-logging-config;
uses facility-logging;
}
}
}
}
}
}
}
}
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4.3. A SYSLOG Example
Requirement:
Enable global logging of two facilities:
kern - severity critical(1)
auth - severity error(3)
Enable console logging of syslogs of severity
critical(1)
Here is the example syslog configuration xml:
<rpc message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<edit-config>
<target>
<running/>
</target>
<config>
<syslog xmlns="urn:cisco:params:xml:ns:yang:syslog">
<global-logging>
<facility>syslogtypes:kern</facility>
<severity>syslogtypes:critical</severity>
<facility>syslogtypes:auth</facility>
<severity>syslogtypes:error</severity>
</global-logging>
<console-logging>
<logging-severity>syslogtypes:critical</logging-severity>
</console-logging>
</syslog>
</config>
</edit-config>
</rpc>
<?xml version="1.0" encoding="UTF-8"?>
<rpc-reply message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<ok/>
</rpc-reply>
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5. Implementation Status
[Note to RFC Editor: Please remove this section before publication.]
This section records the status of known implementations of the Syslog
YANG model at the time of posting of this Internet-Draft.
Cisco Systems, Inc. has implemented the proposed IETF Syslog model
for the Nexus 7000 NXOS OS as a prototype, together with an
augmentation model for operating system specific Syslog configuration
features.
Five leaves were implemented in the base IETF model and three leaves
were implemented in the NXOS specific augmentation model as follows:
Leaf XPATH Sample NXOS CLI Command(s)
syslog:global-logging logging level cron 2
syslog:console-logging logging console 1
syslog:file-logging logging logfile mylog.log 2 4096
syslog:terminal-logging logging monitor 2
syslog:remote-logging *logging server server.cisco.com 2
facility user use-vrf management
*logging source-interface loopback 0
cisco-syslog:logging-timestamp-config logging timestamp milli-seconds
cisco-syslog:origin-id-cfg logging origin-id string abcdef
cisco-syslog:module-logging logging module 1
*The "logging server" and "logging source-interface" commands were
combined into one base model leaf.
The description of implementations in this section is intended to assist
the IETF in its decision processes in progressing drafts to RFCs.
6. Security Considerations
The YANG module defined in this memo is designed to be accessed via
the NETCONF protocol [RFC6241] [RFC6241]. The lowest NETCONF layer
is the secure transport layer and the mandatory-to-implement secure
transport is SSH [RFC6242] [RFC6242]. The NETCONF access control
model [RFC6536] [RFC6536] provides the means to restrict access for
particular NETCONF users to a pre-configured subset of all available
NETCONF protocol operations and content.
There are a number of data nodes defined in the YANG module which are
writable/creatable/deletable (i.e., config true, which is the
default). These data nodes may be considered sensitive or vulnerable
in some network environments. Write operations (e.g., <edit-config>)
to these data nodes without proper protection can have a negative
effect on network operations.
TBD: List specific Subtrees and data nodes and their sensitivity/
vulnerability.
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7. IANA Considerations
This document registers a URI in the IETF XML registry [RFC3688]
[RFC3688]. Following the format in RFC 3688, the following
registration is requested to be made:
URI: urn:ietf:params:xml:ns:yang:syslog
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
This document registers a YANG module in the YANG Module Names
registry [RFC6020].
name: syslog namespace: urn:ietf:params:xml:ns:yang:syslog
prefix: syslog reference: RFC XXXX
8. Acknowledgements
9. Change log [RFC Editor: Please remove]
10. References
[RFC3164] Lonvick, C., "The BSD syslog Protocol", BCP 81, RFC 3164,
August 2001.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC6020] Bjorklund, M., "YANG - A Data Modeling Language for the
Network Configuration Protocol (NETCONF)", RFC 6020,
October 2010.
[RFC6241] Enns, R., Bjorklund, M., Schoenwaelder, J., and A.
Bierman, "Network Configuration Protocol (NETCONF)", RFC
6241, June 2011.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, June 2011.
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[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536, March
2012.
Authors' Addresses
Clyde Wildes
Cisco Systems Inc.
Email: cwildes@cisco.com
Kiran Agrahara Sreenivasa
Brocade Communications Systems
Email: kkoushik@brocade.com
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