Abstract

This project is about creating wrapper libraries to support monitoring and management applications to avoid direct use of kvm(3) and sysctl(3) interfaces. This approach would allow the kernel implementation to change and monitoring applications to be extended without breaking applications and requiring them to be recompiled. For this project, we propose to provide such a library for the network statistics functions (i.e. libnetstat(3)) as a proof of concept, together with methods for building similar libraries for other subsystems.

Description

The goal of this project is to help creation of wrapper libraries to support monitoring and management applications to avoid direct use of the kvm(3) device and the sysctl(3) variables in the FreeBSD kernel. This would allow the kernel implementation to change and monitoring to be extended without breaking applications and requiring them to be recompiled.

The initial idea is based on Robert Watson's libmemstat(3) library, where he created an abstract interface for collecting and providing information on memory allocation statistics. Its design and development was inspired by the following needs:

For this project, we propose to provide a library for the network statistics functions (i.e. libnetstat(3)). Hopefully, it is just a start, lessons learned during the design of this implementation could be used for creating similar libraries for other subsystems as time goes on.

The reason why libnetstat(3) have been chosen, is that the network-related abstractions (e.g. "sockets", "socket buffers") are frequently monitored abstractions, with lot of FreeBSD and third-party tools wanting to show information about them.

Generic Way of Development

There are three parts to be implemented:

For the implementation, we will need to find the abstractions most suitable for the selected applications. For example, the current libmemstat(3) API presents a set for memory types, and allows programs to query various statistics and properties on each type. In our opinion, the same could be implemented for the network statistics.

Project Tasks

Old Features

Task

Status

Responsible

Description

PCB and listen queues abstractions

Done (to be reviewed)

pgj

Add abstractions for Active sockets (protocol control blocks) and listen queues (unaccepted connections, unaccepted incomplete connections, maximum queued connections) for each network protocol, for particular protocol family, for a single protocol.

NIF abstractions

Done (to be reviewed)

pgj

Add abstractions for network interfaces (bytes in/out, dropped packets, watchdog timers, errors, and collisions, packet traffic).

MBUF abstractions

Done (to be reviewed)

pgj

Add abstractions for statistics recorded by memory management routines (mbuf(9)).

BPF abstractions

Done (to be reviewed)

pgj

Add abstractions for bpf(4) peers (packets matched, dropped, received, buffer size, device states).

Routing abstractions

Done (to be reviewed)

pgj

Add abstractions for routing statistics for routing tables, or routing tables for particular address family.

MIF abstractions

Partially done (to be reviewed)

pgj

Add abstractions for IP multicast virtual-interfaces, routing tables, multicast group memberships, multicast routing statistics.

MIF sysctl(8) support

Done (to be reviewed)

pgj

Add sysctl(8) procedures for live monitoring multicast virtual-interfaces and routing tables.

Routing sysctl(8) support

In progress

aman

Add sysctl(8) procedure for live monitoring routing tables.

KNDS abstractions

Review in progress (pgj)

aman

Add abstractions for describing netisr(9)-related statistics.

netstat(1) adaptation

In progress

pgj

Adapt the netstat(1) utility to use libnetstat(3).

nettop(1)

In progress

pgj

Maintain a simple top(1)-like utility for live monitoring.

Versioning statistics

In progress

pgj

Introduce platform-independent versioning in networking statistics.

libnetstat(3) manual page

Not done

none

Create a manual page for libnetstat(3).

Cleaning up

Not done

none

There are some part to be dropped (i.e. not used), and simplified by using macros, for example. It think it would be beneficial to catch the skeleton of the common (allocator, iterator) routines and macrorify it (like in case of queue.h), merge some similar routines.

Support for other protocols

Not done

none

Take care of SCTP, Netgraph, IPX, and AppleTalk protocol stuff.

MIF export fix

Done

aman

Kernel patches for exporting mifs and mroutes are making witness(4) alerts.

Compilation fix

Done

pgj

libnetstat(3) compiles only with -O at the moment due to some pointer tricks.

net/stat.h

Done

pgj

Introduce a kernel-level netstat header to collect common declarations.

New Features

Task

Status

Responsible

Description

NIF sysctl(8) enumeration

In progress

aman

Enumerating network interfaces via sysctl(8) (similarly to ifmib(4)?).

64-bit counters

Deferred

pgj

Add support for multi-platform atomic 64-bit counters for tracking network statistics properly.

SNMP support

Not done

none

Add SNMP support to libnetstat(3), so it could be used for remote hosts where bsnmpd(1) is running.

VIMAGE support

Not done

none

Respect virtualized network stacks, so they can be monitored independently (for example, by a -J jailname flag in netstat(1)).

KVM support

Not done

none

Add support for information extraction from KVM images in an ABI-independent way.

Code

The current version of the implementation can be found in the project's Perforce depot or as unified diff against head.

Contact

Feel free to contact any or all of the contributors in the project.

We usually have regular weekly meetings on #freebsd-libnetstat @ freenode on every Sunday, starting from 08:00 UTC.

Past Contributors

LibNetstat (last edited 2011-08-30 12:34:26 by PáliGáborJános)