PowerBGP

0.5.1

Public/Start-BfdSession.ps1

function Start-BfdSession {
    <#
    .SYNOPSIS
        Starts a single-hop BFD session (UDP, TTL 255, source port 49152-65535).
    .PARAMETER ListenPort
        Local UDP port to receive on (3784 normally).
    .PARAMETER Port
        Remote UDP port to send to (3784 normally).
    #>
    [CmdletBinding()]
    param(
        [Parameter(Mandatory)][string]$RemoteAddress,
        [string]$Name,
        [int]$Port = 3784,
        [int]$ListenPort = 3784,
        [uint32]$DesiredMinTxMs = 500,
        [uint32]$RequiredMinRxMs = 500,
        [ValidateRange(1, 255)][int]$DetectMult = 3
    )
    if (-not $Name) { $Name = $RemoteAddress }
    $reg = Get-PowerBgpRegistry
    $existing = $reg.Bfd[$Name]
    if ($existing -and $existing.State -ne 'Stopped') { throw "BFD session '$Name' already exists." }

    $S = [hashtable]::Synchronized(@{
            Name               = $Name
            Config             = [pscustomobject]@{
                RemoteAddress = $RemoteAddress; RemotePort = $Port; ListenPort = $ListenPort
                DesiredMinTx = $DesiredMinTxMs * 1000; RequiredMinRx = $RequiredMinRxMs * 1000; DetectMult = $DetectMult
            }
            State              = 'Down'
            RemoteState        = $null
            Stop               = $false
            Suppress           = $false
            Sent               = 0
            Received           = 0
            LocalDiscriminator = 0
            LastError          = $null
            History            = [System.Collections.Concurrent.ConcurrentQueue[string]]::new()
            PowerShell         = $null
            Handle             = $null
        })
    $reg.Bfd[$Name] = $S
    Start-PowerBgpRunspace -State $S -Entry 'Invoke-BfdSessionLoop'
    Get-BfdSession -Name $Name
}

function Get-BfdSession {
    [CmdletBinding()]
    param([string]$Name = '*')
    foreach ($S in @((Get-PowerBgpRegistry).Bfd.Values)) {
        if ($S.Name -notlike $Name) { continue }
        [pscustomobject]@{
            PSTypeName    = 'PowerBGP.BfdSession'
            Name          = $S.Name
            State         = $S.State
            RemoteState   = $S.RemoteState
            Remote        = '{0}:{1}' -f $S.Config.RemoteAddress, $S.Config.RemotePort
            TxMs          = $S.Config.DesiredMinTx / 1000
            RxMs          = $S.Config.RequiredMinRx / 1000
            DetectMult    = $S.Config.DetectMult
            Sent          = $S.Sent
            Received      = $S.Received
            Suppressed    = [bool]$S.Suppress
            LastError     = $S.LastError
            History       = $S.History.ToArray()
        }
    }
}

function Stop-BfdSession {
    <#
    .SYNOPSIS
        Stops a BFD session. It stays configured (State 'Stopped') so Resume-BfdSession can restart it;
        use Remove-BfdSession to delete it.
    #>
    [CmdletBinding()]
    param([Parameter(Mandatory, ValueFromPipelineByPropertyName)][string]$Name)
    process {
        $S = (Get-PowerBgpRegistry).Bfd[$Name]
        if (-not $S) { Write-Error "No such BFD session '$Name'."; return }
        Stop-PowerBgpRunspace $S
        $S.State = 'Stopped'
    }
}

function Resume-BfdSession {
    [CmdletBinding()]
    param([Parameter(Mandatory, ValueFromPipelineByPropertyName)][string]$Name)
    process {
        $old = (Get-PowerBgpRegistry).Bfd[$Name]
        if (-not $old) { Write-Error "No such BFD session '$Name'."; return }
        $c = $old.Config
        $null = Start-BfdSession -Name $Name -RemoteAddress $c.RemoteAddress -Port $c.RemotePort -ListenPort $c.ListenPort `
            -DesiredMinTxMs ($c.DesiredMinTx / 1000) -RequiredMinRxMs ($c.RequiredMinRx / 1000) -DetectMult $c.DetectMult
        Get-BfdSession -Name $Name
    }
}

function Update-BfdSession {
    <#
    .SYNOPSIS
        Changes a BFD session's stored settings. A running session is restarted (it goes Down and renegotiates).
    #>
    [CmdletBinding()]
    param(
        [Parameter(Mandatory)][string]$Name,
        [int]$Port,
        [int]$ListenPort,
        [uint32]$DesiredMinTxMs,
        [uint32]$RequiredMinRxMs,
        [ValidateRange(1, 255)][int]$DetectMult
    )
    $S = (Get-PowerBgpRegistry).Bfd[$Name]
    if (-not $S) { throw "No such BFD session '$Name'." }
    $wasRunning = $S.State -ne 'Stopped'
    if ($wasRunning) { Stop-BfdSession -Name $Name }
    $c = $S.Config
    if ($PSBoundParameters.ContainsKey('Port')) { $c.RemotePort = $Port }
    if ($PSBoundParameters.ContainsKey('ListenPort')) { $c.ListenPort = $ListenPort }
    if ($PSBoundParameters.ContainsKey('DesiredMinTxMs')) { $c.DesiredMinTx = $DesiredMinTxMs * 1000 }
    if ($PSBoundParameters.ContainsKey('RequiredMinRxMs')) { $c.RequiredMinRx = $RequiredMinRxMs * 1000 }
    if ($PSBoundParameters.ContainsKey('DetectMult')) { $c.DetectMult = $DetectMult }
    if ($wasRunning) { Resume-BfdSession -Name $Name } else { Get-BfdSession -Name $Name }
}

function Remove-BfdSession {
    [CmdletBinding(SupportsShouldProcess)]
    param([Parameter(Mandatory, ValueFromPipelineByPropertyName)][string]$Name)
    process {
        $reg = Get-PowerBgpRegistry
        $S = $reg.Bfd[$Name]
        if (-not $S) { Write-Error "No such BFD session '$Name'."; return }
        if ($PSCmdlet.ShouldProcess($Name, 'Remove BFD session')) {
            Stop-PowerBgpRunspace $S
            $reg.Bfd.Remove($Name)
        }
    }
}

function Set-BfdSession {
    <#
    .SYNOPSIS
        Fault injection: -Suppress $true stops sending BFD control packets while the session object stays alive.
    #>
    [CmdletBinding()]
    param([Parameter(Mandatory)][string]$Name, [Parameter(Mandatory)][bool]$Suppress)
    $S = (Get-PowerBgpRegistry).Bfd[$Name]
    if (-not $S) { throw "No such BFD session '$Name'." }
    $S.Suppress = $Suppress
}