| NETMOD WG | C. Wildes, Ed. |
| Internet-Draft | K. Koushik, Ed. |
| Intended status: Standards Track | Cisco Systems Inc. |
| Expires: May 17, 2017 | November 13, 2016 |
A YANG Data Model for Syslog Configuration
draft-ietf-netmod-syslog-model-11
This document describes a data model for the configuration of syslog.
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 Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on May 17, 2017.
Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
Operating systems, processes and applications generate messages indicating their own status or the occurrence 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 [RFC5424] in this RFC.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
The term "originator" is defined in [RFC5424]: an "originator" generates syslog content to be carried in a message.
The terms "relay" and "collectors" are as defined in [RFC5424].
This document defines a YANG [RFC6020] configuration data model that may be used to configure the syslog feature running on a system. YANG models can be used with network management protocols such as NETCONF [RFC6241] to install, manipulate, and delete the configuration of network devices.
The data model makes use of the YANG "feature" construct which allows implementations to support only those syslog features that lie within their capabilities.
This module can be used to configure the syslog application conceptual layers as implemented on the target system [RFC5424].
The syslog model was designed by comparing various syslog features implemented by various vendors' in different implementations.
This draft addresses the common leafs between implementations 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 originators, and collectors. The following digram shows syslog messages flowing from an originator, to collectors where suppression filtering can take place.
Many vendors extend the list of facilities available for logging in their implementation. An example is included in Extending Facilities [extending_facilities].
Originators
+-------------+ +-------------+ +-------------+ +-------------+
| Various | | OS | | | | Remote |
| Components | | Kernel | | Line Cards | | Servers |
+-------------+ +-------------+ +-------------+ +-------------+
+-------------+ +-------------+ +-------------+ +-------------+
| SNMP | | Interface | | Standby | | Syslog |
| Events | | Events | | Supervisor | | Itself |
+-------------+ +-------------+ +-------------+ +-------------+
| |
+----------------------------------------------------------------+
|
|
|
|
+-----------+------------+--------------+
| | | |
v v v |
Collectors |
+----------+ +----------+ +----------+ |
| | | Log | | Log | |
| Console | | Buffer | | File(s) | |
+----------+ +----------+ +----------+ |
|
+-+-------------+
| |
v v
+----------------+ +-----------+
|Remote Relay(s)/| |User |
|Collectors(s) | |Sessions(s)|
+----------------+ +-----------+
Figure 1. Syslog Processing Flow
The leaves in the base syslog model actions container correspond to each message collector:
Within each action, a selector is used to filter syslog messages. A selector consists of two parts: one or more facility-severity matches, and if supported via the select-match feature, an optional regular expression pattern match that is performed on the SYSLOG-MSG field.
The facility is one of a specific syslogtypes:syslog-facility, none, or all facilities. None is a special case that can be used to disable an action.
The severity is one of syslogtypes:severity, all severities, or none. None is a special case that can be used to disable a facility. When filtering severity, the default comparison is that all messages of the specified severity and higher are logged. This is shown in the model as ?default equals-or-higher?. This behavior can be altered if the select-sev-compare feature is enabled to specify: ?equals? to specify only this single severity; ?not-equals? to ignore that severity; ?equals-or-higher? to specify all messages of the specified severity and higher.
Optional features are used to specified functionality that is present in specific vendor configurations.
A simplified graphical representation of the complete data tree is presented here.
Each node is printed as:
<status> <flags> <name> <opts> <type> <if-features>
+ for current
x for deprecated
o for obsolete
<status> is one of:
rw for configuration data
ro for non-configuration data
-x for rpcs
-n for notifications
<flags> is one of:
(<name>) means that the node is a choice node
:(<name>) means that the node is a case node
<name> is the name of the node
If the node is augmented into the tree from another module, its name is printed as <prefix>:<name>.
? for an optional leaf or choice
! for a presence container
* for a leaf-list or list
[<keys>] for a list's keys
<opts> is one of:
<type> is the name of the type for leafs and leaf-lists
If the type is a leafref, the type is printed as "-> TARGET", where TARGET is either the leafref path, with prefixed removed if possible.
<if-features> is the list of features this node depends on, printed within curly brackets and a question mark "{...}?"
module: ietf-syslog
+--rw syslog!
+--rw actions
+--rw console!
| +--rw selector
| +--rw (selector-facility)
| | +--:(facility)
| | | +--rw no-facilities? empty
| | +--:(name)
| | +--rw facility-list* [facility]
| | +--rw facility union
| | +--rw severity union
| | +--rw compare? enumeration {select-sev-compare}?
| +--rw pattern-match? string {select-match}?
+--rw buffer {buffer-action}?
| +--rw selector
| | +--rw (selector-facility)
| | | +--:(facility)
| | | | +--rw no-facilities? empty
| | | +--:(name)
| | | +--rw facility-list* [facility]
| | | +--rw facility union
| | | +--rw severity union
| | | +--rw compare? enumeration {select-sev-compare}?
| | +--rw pattern-match? string {select-match}?
| +--rw structured-data? boolean {structured-data}?
| +--rw buffer-limit-bytes? uint64 {buffer-limit-bytes}?
| +--rw buffer-limit-messages? uint64 {buffer-limit-messages}?
+--rw file
| +--rw log-file* [name]
| +--rw name inet:uri
| +--rw selector
| | +--rw (selector-facility)
| | | +--:(facility)
| | | | +--rw no-facilities? empty
| | | +--:(name)
| | | +--rw facility-list* [facility]
| | | +--rw facility union
| | | +--rw severity union
| | | +--rw compare? enumeration {select-sev-compare}?
| | +--rw pattern-match? string {select-match}?
| +--rw structured-data? boolean {structured-data}?
| +--rw file-rotation
| +--rw number-of-files? uint32 {file-limit-size}?
| +--rw max-file-size? uint64 {file-limit-size}?
| +--rw rollover? uint32 {file-limit-duration}?
| +--rw retention? uint16 {file-limit-duration}?
+--rw remote
| +--rw destination* [name]
| +--rw name string
| +--rw (transport)
| | +--:(tcp)
| | | +--rw tcp
| | | +--rw address? inet:host
| | | +--rw port? inet:port-number
| | +--:(udp)
| | +--rw udp
| | +--rw address? inet:host
| | +--rw port? inet:port-number
| +--rw selector
| | +--rw (selector-facility)
| | | +--:(facility)
| | | | +--rw no-facilities? empty
| | | +--:(name)
| | | +--rw facility-list* [facility]
| | | +--rw facility union
| | | +--rw severity union
| | | +--rw compare? enumeration {select-sev-compare}?
| | +--rw pattern-match? string {select-match}?
| +--rw structured-data? boolean {structured-data}?
| +--rw facility-override? identityref
| +--rw source-interface? if:interface-ref
| +--rw signing-options! {signed-messages}?
| +--rw cert-initial-repeat uint16
| +--rw cert-resend-delay uint16
| +--rw cert-resend-count uint16
| +--rw max-delay uint16
| +--rw number-resends uint16
| +--rw resend-delay uint16
| +--rw resend-count uint16
+--rw session
+--rw all-users!
| +--rw selector
| +--rw (selector-facility)
| | +--:(facility)
| | | +--rw no-facilities? empty
| | +--:(name)
| | +--rw facility-list* [facility]
| | +--rw facility union
| | +--rw severity union
| | +--rw compare? enumeration {select-sev-compare}?
| +--rw pattern-match? string {select-match}?
+--rw user* [name]
+--rw name string
+--rw selector
+--rw (selector-facility)
| +--:(facility)
| | +--rw no-facilities? empty
| +--:(name)
| +--rw facility-list* [facility]
| +--rw facility union
| +--rw severity union
| +--rw compare? enumeration {select-sev-compare}?
+--rw pattern-match? string {select-match}?
Figure 2. ietf-syslog Module Tree
This module references [RFC5424].
<CODE BEGINS> file "ietf-syslog-types.yang"
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: Lou Berger
<mailto:lberger@labn.net>
WG Chair: Kent Watsen
<mailto:kwatsen@juniper.net>
Editor: Kiran Agrahara Sreenivasa
<mailto:kkoushik@cisco.com>
Editor: Clyde Wildes
<mailto:cwildes@cisco.com>";
description
"This module contains a collection of YANG type definitions for
SYSLOG.
Copyright (c) 2016 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and
'OPTIONAL' in the module text are to be interpreted as described
in RFC 2119 (http://tools.ietf.org/html/rfc2119).
This version of this YANG module is part of RFC XXXX
(http://tools.ietf.org/html/rfcXXXX); see the RFC itself for
full legal notices.";
reference
"RFC 5424: The Syslog Protocol";
revision 2016-11-13 {
description
"Initial Revision";
reference
"RFC XXXX: SYSLOG YANG Model";
}
typedef severity {
type enumeration {
enum "emergency" {
value 0;
description
"The severity level 'Emergency' indicating that the system
is unusable.";
}
enum "alert" {
value 1;
description
"The severity level 'Alert' indicating that an action must be
taken immediately.";
}
enum "critical" {
value 2;
description
"The severity level 'Critical' indicating a critical condition.";
}
enum "error" {
value 3;
description
"The severity level 'Error' indicating an error condition.";
}
enum "warning" {
value 4;
description
"The severity level 'Warning' indicating a warning condition.";
}
enum "notice" {
value 5;
description
"The severity level 'Notice' indicating a normal but significant
condition.";
}
enum "info" {
value 6;
description
"The severity level 'Info' indicating an informational message.";
}
enum "debug" {
value 7;
description
"The severity level 'Debug' indicating a debug-level message.";
}
}
description
"The definitions for Syslog message severity as per RFC 5424.";
}
identity syslog-facility {
description
"This identity is used as a base for all syslog facilities as
per RFC 5424.";
}
identity kern {
base syslog-facility;
description
"The facility for kernel messages (0) as defined in RFC 5424.";
}
identity user {
base syslog-facility;
description
"The facility for user-level messages (1) as defined in RFC 5424.";
}
identity mail {
base syslog-facility;
description
"The facility for the mail system (2) as defined in RFC 5424.";
}
identity daemon {
base syslog-facility;
description
"The facility for the system daemons (3) as defined in RFC 5424.";
}
identity auth {
base syslog-facility;
description
"The facility for security/authorization messages (4) as defined
in RFC 5424.";
}
identity syslog {
base syslog-facility;
description
"The facility for messages generated internally by syslogd
facility (5) as defined in RFC 5424.";
}
identity lpr {
base syslog-facility;
description
"The facility for the line printer subsystem (6) as defined in
RFC 5424.";
}
identity news {
base syslog-facility;
description
"The facility for the network news subsystem (7) as defined in
RFC 5424.";
}
identity uucp {
base syslog-facility;
description
"The facility for the UUCP subsystem (8) as defined in RFC 5424.";
}
identity cron {
base syslog-facility;
description
"The facility for the clock daemon (9) as defined in RFC 5424.";
}
identity authpriv {
base syslog-facility;
description
"The facility for privileged security/authorization messages (10)
as defined in RFC 5424.";
}
identity ftp {
base syslog-facility;
description
"The facility for the FTP daemon (11) as defined in RFC 5424.";
}
identity ntp {
base syslog-facility;
description
"The facility for the NTP subsystem (12) as defined in RFC 5424.";
}
identity audit {
base syslog-facility;
description
"The facility for log audit messages (13) as defined in RFC 5424.";
}
identity console {
base syslog-facility;
description
"The facility for log alert messages (14) as defined in RFC 5424.";
}
identity cron2 {
base syslog-facility;
description
"The facility for the second clock daemon (15) as defined in
RFC 5424.";
}
identity local0 {
base syslog-facility;
description
"The facility for local use 0 messages (16) as defined in
RFC 5424.";
}
identity local1 {
base syslog-facility;
description
"The facility for local use 1 messages (17) as defined in
RFC 5424.";
}
identity local2 {
base syslog-facility;
description
"The facility for local use 2 messages (18) as defined in
RFC 5424.";
}
identity local3 {
base syslog-facility;
description
"The facility for local use 3 messages (19) as defined in
RFC 5424.";
}
identity local4 {
base syslog-facility;
description
"The facility for local use 4 messages (20) as defined in
RFC 5424.";
}
identity local5 {
base syslog-facility;
description
"The facility for local use 5 messages (21) as defined in
RFC 5424.";
}
identity local6 {
base syslog-facility;
description
"The facility for local use 6 messages (22) as defined in
RFC 5424.";
}
identity local7 {
base syslog-facility;
description
"The facility for local use 7 messages (23) as defined in
RFC 5424.";
}
}
<CODE ENDS>
Figure 3. ietf-syslog-types Module
This module imports typedefs from [RFC6021] and [RFC7223], and it references [RFC5424], [RFC5425], [RFC5426], [RFC6587], and [RFC5848].
<CODE BEGINS> file "ietf-syslog.yang"
module ietf-syslog {
namespace "urn:ietf:params:xml:ns:yang:ietf-syslog";
prefix syslog;
import ietf-inet-types {
prefix inet;
}
import ietf-interfaces {
prefix if;
}
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: Lou Berger
<mailto:lberger@labn.net>
WG Chair: Kent Watsen
<mailto:kwatsen@juniper.net>
Editor: Kiran Agrahara Sreenivasa
<mailto:kkoushik@cisco.com>
Editor: Clyde Wildes
<mailto:cwildes@cisco.com>";
description
"This module contains a collection of YANG definitions
for syslog configuration.
Copyright (c) 2016 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject to
the license terms contained in, the Simplified BSD License set
forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL
NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and
'OPTIONAL' in the module text are to be interpreted as described
in RFC 2119 (http://tools.ietf.org/html/rfc2119).
This version of this YANG module is part of RFC XXXX
(http://tools.ietf.org/html/rfcXXXX); see the RFC itself for
full legal notices.";
reference
"RFC 5424: The Syslog Protocol
RFC 5426: Transmission of Syslog Messages over UDP
RFC 6587: Transmission of Syslog Messages over TCP
RFC 5848: Signed Syslog Messages";
revision 2016-11-13 {
description
"Initial Revision";
reference
"RFC XXXX: Syslog YANG Model";
}
feature buffer-action {
description
"This feature indicates that the local memory logging buffer
action is supported.";
}
feature buffer-limit-bytes {
description
"This feature indicates that the local memory logging buffer
is limited in size using a limit expressed in bytes.";
}
feature buffer-limit-messages {
description
"This feature indicates that the local memory logging buffer
is limited in size using a limit expressed in number of log
messages.";
}
feature file-limit-size {
description
"This feature indicates that file logging resources
are managed using size and number limits.";
}
feature file-limit-duration {
description
"This feature indicates that file logging resources
are managed using time based limits.";
}
feature select-sev-compare {
description
"This feature represents the ability to select messages
using the additional operators equal to, or not equal to
when comparing the syslog message severity.";
}
feature select-match {
description
"This feature represents the ability to select messages based
on a Posix 1003.2 regular expression pattern match.";
}
feature structured-data {
description
"This feature represents the ability to log messages
in structured-data format as per RFC 5424.";
}
feature signed-messages {
description
"This feature represents the ability to configure signed
syslog messages according to RFC 5848.";
}
grouping log-severity {
description
"This grouping defines the severity value that is used to
select log messages.";
leaf severity {
type union {
type syslogtypes:severity;
type enumeration {
enum none {
value -2;
description
"This enum describes the case where no severities
are selected.";
}
enum all {
value -1;
description
"This enum describes the case where all severities
are selected.";
}
}
}
mandatory true;
description
"This leaf specifies the syslog message severity. When
severity is specified, the default severity comparison
is all messages of the specified severity and greater are
selected. 'all' is a special case which means all severities
are selected. 'none' is a special case which means that
no selection should occur or disable this filter.";
}
leaf compare {
when '../severity != "all" and
../severity != "none"' {
description
"The compare leaf is not applicable for severity 'all' or
severity 'none'";
}
if-feature select-sev-compare;
type enumeration {
enum equals-or-higher {
description
"This enum specifies all messages of the specified
severity and higher are logged according to the
given log-action";
}
enum equals {
description
"This enum specifies all messages that are for
the specified severity are logged according to the
given log-action";
}
enum not-equals {
description
"This enum specifies all messages that are not for
the specified severity are logged according to the
given log-action";
}
}
default equals-or-higher;
description
"This leaf describes the option to specify how the
severity comparison is performed.";
}
}
grouping selector {
description
"This grouping defines a syslog selector which is used to
select log messages for the log-action (console, file,
remote, etc). Choose one of the following:
no-facility
facility [<facility> <severity>...]";
container selector {
description
"This container describes the log selector parameters
for syslog.";
choice selector-facility {
mandatory true;
description
"This choice describes the option to specify no
facilities, or a specific facility which can be
all for all facilities.";
case facility {
description
"This case specifies no facilities will match when
comparing the syslog message facility. This is a
method that can be used to effectively disable a
particular log-action (buffer, file, etc).";
leaf no-facilities {
type empty;
description
"This leaf specifies that no facilities are selected
for this log-action.";
}
}
case name {
description
"This case specifies one or more specified facilities
will match when comparing the syslog message facility.";
list facility-list {
key facility;
description
"This list describes a collection of syslog
facilities and severities.";
leaf facility {
type union {
type identityref {
base syslogtypes:syslog-facility;
}
type enumeration {
enum all {
description
"This enum describes the case where all
facilities are requested.";
}
}
}
description
"The leaf uniquely identifies a syslog facility.";
}
uses log-severity;
}
}
}
leaf pattern-match {
if-feature select-match;
type string;
description
"This leaf desribes a Posix 1003.2 regular expression
string that can be used to select a syslog message for
logging. The match is performed on the RFC 5424
SYSLOG-MSG field.";
}
}
}
grouping structured-data {
description
"This grouping defines the syslog structured data option
which is used to select the format used to write log
messages.";
leaf structured-data {
if-feature structured-data;
type boolean;
default false;
description
"This leaf describes how log messages are written.
If true, messages will be written with one or more
STRUCTURED-DATA elements as per RFC5424; if false,
messages will be written with STRUCTURED-DATA =
NILVALUE.";
}
}
container syslog {
presence "Enables logging.";
description
"This container describes the configuration parameters for
syslog.";
container actions {
description
"This container describes the log-action parameters
for syslog.";
container console {
presence "Enables logging console configuration";
description
"This container describes the configuration parameters for
console logging.";
uses selector;
}
container buffer {
if-feature buffer-action;
description
"This container describes the configuration parameters for
local memory buffer logging. The buffer is circular in
nature, so newer messages overwrite older messages after
the buffer is filled. The method used to read syslog messages
from the buffer is supplied by the local implementation.";
uses selector;
uses structured-data;
leaf buffer-limit-bytes {
if-feature buffer-limit-bytes;
type uint64;
units "bytes";
description
"This leaf configures the amount of memory (in bytes) that
will be dedicated to the local memory logging buffer.
The default value varies by implementation.";
}
leaf buffer-limit-messages {
if-feature buffer-limit-messages;
type uint64;
units "log messages";
description
"This leaf configures the number of log messages that
will be dedicated to the local memory logging buffer.
The default value varies by implementation.";
}
}
container file {
description
"This container describes the configuration parameters for
file logging. If file-archive limits are not supplied, it
is assumed that the local implementation defined limits will
be used.";
list log-file {
key "name";
description
"This list describes a collection of local logging
files.";
leaf name {
type inet:uri {
pattern 'file:.*';
}
description
"This leaf specifies the name of the log file which
MUST use the uri scheme file:.";
}
uses selector;
uses structured-data;
container file-rotation {
description
"This container describes the configuration
parameters for log file rotation.";
leaf number-of-files {
if-feature file-limit-size;
type uint32;
description
"This leaf specifies the maximum number of log
files retained. Specify 1 for implementations
that only support one log file.";
}
leaf max-file-size {
if-feature file-limit-size;
type uint64;
units "megabytes";
description
"This leaf specifies the maximum log file size.";
}
leaf rollover {
if-feature file-limit-duration;
type uint32;
units "minutes";
description
"This leaf specifies the length of time that log
events should be written to a specific log file.
Log events that arrive after the rollover period
cause the current log file to be closed and a new
log file to be opened.";
}
leaf retention {
if-feature file-limit-duration;
type uint16;
units "hours";
description
"This leaf specifies the length of time that
completed/closed log event files should be stored
in the file system before they are deleted.";
}
}
}
}
container remote {
description
"This container describes the configuration parameters for
forwarding syslog messages to remote relays or collectors.";
list destination {
key "name";
description
"This list describes a collection of remote logging
destinations.";
leaf name {
type string;
description
"An arbitrary name for the endpoint to connect to.";
}
choice transport {
mandatory true;
description
"This choice describes the transport option.";
case tcp {
container tcp {
description
"This container describes the TCP transport
options.";
reference
"RFC 6587: Transmission of Syslog Messages over TCP";
leaf address {
type inet:host;
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.";
}
leaf port {
type inet:port-number;
default 514;
description
"This leaf specifies the port number used to
deliver messages to the remote server.";
}
}
}
case udp {
container udp {
description
"This container describes the UDP transport
options.";
reference
"RFC 5426: Transmission of Syslog Messages over UDP";
leaf address {
type inet:host;
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.";
}
leaf port {
type inet:port-number;
default 514;
description
"This leaf specifies the port number used to
deliver messages to the remote server.";
}
}
}
}
uses selector;
uses structured-data;
leaf facility-override {
type identityref {
base syslogtypes:syslog-facility;
}
description
"If specified, this leaf specifies the facility used
to override the facility in messages delivered to the
remote server.";
}
leaf source-interface {
type if:interface-ref;
description
"This leaf sets the source interface to be used to send
message to the remote syslog server. If not set,
messages sent to a remote syslog server will
contain the IP address of the interface the syslog
message uses to exit the network element";
}
container signing-options {
if-feature signed-messages;
presence
"If present, syslog-signing options is activated.";
description
"This container describes the configuration
parameters for signed syslog messages as described
by RFC 5848.";
reference
"RFC 5848: Signed Syslog Messages";
leaf cert-initial-repeat {
type uint16;
mandatory true;
description
"This leaf specifies the number of times each
Certificate Block should be sent before the first
message is sent.";
}
leaf cert-resend-delay {
type uint16;
units "seconds";
mandatory true;
description
"This leaf specifies the maximum time delay in
seconds until resending the Certificate Block.";
}
leaf cert-resend-count {
type uint16;
mandatory true;
description
"This leaf specifies the maximum number of other
syslog messages to send until resending the
Certificate Block.";
}
leaf max-delay {
type uint16;
units "seconds";
mandatory true;
description
"This leaf specifies when to generate a new
Signature Block. If this many seconds have
elapsed since the message with the first message
number of the Signature Block was sent, a new
Signature Block should be generated.";
}
leaf number-resends {
type uint16;
mandatory true;
description
"This leaf specifies the number of times a
Signature Block is resent. (It is recommended to
select a value of greater than 0 in particular
when the UDP transport [RFC5426] is used.).";
}
leaf resend-delay {
type uint16;
units "seconds";
mandatory true;
description
"This leaf specifies when to send the next
Signature Block transmission based on time. If
this many seconds have elapsed since the previous
sending of this Signature Block, resend it.";
}
leaf resend-count {
type uint16;
mandatory true;
description
"This leaf specifies when to send the next
Signature Block transmission based on a count.
If this many other syslog messages have been sent
since the previous sending of this Signature
Block, resend it.";
}
}
}
}
container session {
description
"This container describes the configuration parameters for
user CLI session logging configuration.";
container all-users {
presence "Enables logging to all user sessions.";
description
"This container describes the configuration
parameters for all users.";
uses selector;
}
list user {
key "name";
description
"This list describes a collection of user names.";
leaf name {
type string;
description
"This leaf uniquely describes a user name which
is the login name of the user whose session
is to receive log messages.";
}
uses selector;
}
}
}
}
}
<CODE ENDS>
Figure 4. ietf-syslog Module
Requirement:
Enable console logging of syslogs of severity critical
Here is the example syslog configuration xml:
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<syslog xmlns="urn:ietf:params:xml:ns:yang:ietf-syslog"
xmlns:syslog="urn:ietf:params:xml:ns:yang:ietf-syslog">
<actions>
<console>
<selector>
<facility-list>
<facility>all</facility>
<severity>critical</severity>
</facility>
</selector>
</console>
</actions>
</syslog>
</config>
Enable remote logging of syslogs to udp destination 2001:db8:a0b:12f0::1
for facility auth, severity error
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<syslog xmlns="urn:ietf:params:xml:ns:yang:ietf-syslog"
xmlns:syslog="urn:ietf:params:xml:ns:yang:ietf-syslog">
<actions>
<remote>
<destination>
<name>remote1</name>
<udp>
<address>2001:db8:a0b:12f0::1</address>
</udp>
<selector>
<facility-list>
<facility xmlns:syslogtypes=
"urn:ietf:params:xml:ns:yang:ietf-syslog-types">
syslogtypes:auth</facility>
<severity>error</severity>
<facility>
<selector>
</destination>
</remote>
</actions>
</syslog>
</config>
Figure 5. ietf-syslog Examples
The authors wish to thank the following who commented on this proposal:
This document registers two URIs in the IETF XML registry [RFC3688].
Following the format in RFC 3688, the following registration is requested to be made:
URI: urn:ietf:params:xml:ns:yang:ietf-syslog-types
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: ietf-syslog-types namespace: urn:ietf:params:xml:ns:yang:ietf-syslog-types
prefix: ietf-syslog-types reference: RFC XXXX
Following the format in RFC 3688, the following registration is requested to be made:
URI: urn:ietf:params:xml:ns:yang:ietf-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: ietf-syslog namespace: urn:ietf:params:xml:ns:yang:ietf-syslog
prefix: ietf-syslog
reference: RFC XXXX
The YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH [RFC6242]. The NETCONF access control model [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.
Network administrators must take the time to estimate the appropriate memory limits caused by the configuration of actions/buffer using buffer-limit-bytes and/or buffer-limit-messages where necessary to limit the amount of memory used.
Network administrators must take the time to estimate the appropriate storage capacity caused by the configuration of actions/file using file-archive attributes to limit storage used.
It is the responsibility of the network administrator to ensure that the configured message flow does not overwhelm system resources.
It is the responsibility of the network admisintrator to ensure that the messages are actually going to the intended recipients.
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC5424] | Gerhards, R., "The Syslog Protocol", RFC 5424, DOI 10.17487/RFC5424, March 2009. |
| [RFC5426] | Okmianski, A., "Transmission of Syslog Messages over UDP", RFC 5426, DOI 10.17487/RFC5426, March 2009. |
| [RFC5848] | Kelsey, J., Callas, J. and A. Clemm, "Signed Syslog Messages", RFC 5848, DOI 10.17487/RFC5848, May 2010. |
| [RFC6020] | Bjorklund, M., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010. |
| [RFC6021] | Schoenwaelder, J., "Common YANG Data Types", RFC 6021, DOI 10.17487/RFC6021, October 2010. |
| [RFC6587] | Gerhards, R. and C. Lonvick, "Transmission of Syslog Messages over TCP", RFC 6587, DOI 10.17487/RFC6587, April 2012. |
| [RFC7223] | Bjorklund, M., "A YANG Data Model for Interface Management", RFC 7223, DOI 10.17487/RFC7223, May 2014. |
| [RFC3688] | Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004. |
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011. |
| [RFC6242] | Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011. |
Many vendors extend the list of facilities available for logging in their implementation. Additional facilities may not work with the syslog protocol as defined in [RFC5424] and hence such facilities apply for local syslog-like logging functionality.
The following is an example that shows how additional facilities could be added to the list of available facilities (in this example two facilities are added):
module vendor-syslog-types-example {
namespace "urn:vendor:params:xml:ns:yang:vendor-syslog-types";
prefix vendor-syslogtypes;
import ietf-syslog-types {
prefix syslogtypes;
}
organization "Example, Inc.";
contact
"Example, Inc.
Customer Service
E-mail: syslog-yang@example.com";
description
"This module contains a collection of vendor-specific YANG type
definitions for SYSLOG.";
revision 2016-11-13 {
description
"Version 1.0";
reference
"Vendor SYSLOG Types: SYSLOG YANG Model";
}
identity vendor_specific_type_1 {
base syslogtypes:syslog-facility;
}
identity vendor_specific_type_2 {
base syslogtypes:syslog-facility;
}
}