pf

README

PF Input Plugin

The pf plugin gathers information from the FreeBSD/OpenBSD pf firewall. Currently it can retrieve information about the state table: the number of current entries in the table, and counters for the number of searches, inserts, and removals to the table.

The pf plugin retrieves this information by invoking the pfstat command. The pfstat command requires read access to the device file /dev/pf. You have several options to permit telegraf to run pfctl:

• Run telegraf as root. This is strongly discouraged.
• Change the ownership and permissions for /dev/pf such that the user telegraf runs at can read the /dev/pf device file. This is probably not that good of an idea either.
• Configure sudo to grant telegraf to run pfctl as root. This is the most restrictive option, but require sudo setup.
• Add "telegraf" to the "proxy" group as /dev/pf is owned by root:proxy.

Using sudo

You may edit your sudo configuration with the following:

telegraf ALL=(root) NOPASSWD: /sbin/pfctl -s info

Configuration

# Gather counters from PF
[[inputs.pf]]
  ## PF require root access on most systems.
  ## Setting 'use_sudo' to true will make use of sudo to run pfctl.
  ## Users must configure sudo to allow telegraf user to run pfctl with no password.
  ## pfctl can be restricted to only list command "pfctl -s info".
  use_sudo = false

Metrics

• pf
  • entries (integer, count)
  • searches (integer, count)
  • inserts (integer, count)
  • removals (integer, count)
  • match (integer, count)
  • bad-offset (integer, count)
  • fragment (integer, count)
  • short (integer, count)
  • normalize (integer, count)
  • memory (integer, count)
  • bad-timestamp (integer, count)
  • congestion (integer, count)
  • ip-option (integer, count)
  • proto-cksum (integer, count)
  • state-mismatch (integer, count)
  • state-insert (integer, count)
  • state-limit (integer, count)
  • src-limit (integer, count)
  • synproxy (integer, count)

Example Output

> pfctl -s info
Status: Enabled for 0 days 00:26:05           Debug: Urgent

State Table                          Total             Rate
  current entries                        2
  searches                           11325            7.2/s
  inserts                                5            0.0/s
  removals                               3            0.0/s
Counters
  match                              11226            7.2/s
  bad-offset                             0            0.0/s
  fragment                               0            0.0/s
  short                                  0            0.0/s
  normalize                              0            0.0/s
  memory                                 0            0.0/s
  bad-timestamp                          0            0.0/s
  congestion                             0            0.0/s
  ip-option                              0            0.0/s
  proto-cksum                            0            0.0/s
  state-mismatch                         0            0.0/s
  state-insert                           0            0.0/s
  state-limit                            0            0.0/s
  src-limit                              0            0.0/s
  synproxy                               0            0.0/s

> ./telegraf --config telegraf.conf --input-filter pf --test
* Plugin: inputs.pf, Collection 1
> pf,host=columbia entries=3i,searches=2668i,inserts=12i,removals=9i 1510941775000000000

Documentation

Index

• Variables
• type Entry
• type PF
  • func (pf *PF) Gather(acc telegraf.Accumulator) error
  • func (*PF) SampleConfig() string

Variables

var CounterTable = []*Entry{
	{"match", "match", -1},
	{"bad-offset", "bad-offset", -1},
	{"fragment", "fragment", -1},
	{"short", "short", -1},
	{"normalize", "normalize", -1},
	{"memory", "memory", -1},
	{"bad-timestamp", "bad-timestamp", -1},
	{"congestion", "congestion", -1},
	{"ip-option", "ip-option", -1},
	{"proto-cksum", "proto-cksum", -1},
	{"state-mismatch", "state-mismatch", -1},
	{"state-insert", "state-insert", -1},
	{"state-limit", "state-limit", -1},
	{"src-limit", "src-limit", -1},
	{"synproxy", "synproxy", -1},
}

var StateTable = []*Entry{
	{"entries", "current entries", -1},
	{"searches", "searches", -1},
	{"inserts", "inserts", -1},
	{"removals", "removals", -1},
}

Types

type Entry

type Entry struct {
	Field      string
	PfctlTitle string
	Value      int64
}

type PF

type PF struct {
	PfctlCommand string
	PfctlArgs    []string
	UseSudo      bool
	StateTable   []*Entry
	// contains filtered or unexported fields
}

func (*PF) Gather

func (pf *PF) Gather(acc telegraf.Accumulator) error

Gather is the entrypoint for the plugin.

func (*PF) SampleConfig

func (*PF) SampleConfig() string