Src/Private/Convert-AbrFgtSubnetToCIDR.ps1
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function Convert-AbrFgtSubnetToCIDR { <# .SYNOPSIS Used by As Built Report to convert IP/Subnet to CIDR notation. .DESCRIPTION Converts IP addresses and subnet masks to CIDR notation format for Fortinet FortiGate As Built Report. .NOTES Version: 0.1.0 Author: Alexis La Goutte Twitter: @alagoutte Github: alagoutte Credits: Iain Brighton (@iainbrighton) - PScribo module .EXAMPLE Convert-AbrFgtSubnetToCIDR "192.168.1.0 255.255.255.0" Returns: 192.168.1.0/24 .EXAMPLE Convert-AbrFgtSubnetToCIDR "10.0.0.0/8" Returns: 10.0.0.0/8 .LINK https://github.com/AsBuiltReport/AsBuiltReport.Fortinet.FortiGate #> [CmdletBinding()] [OutputType([System.String])] param ( [Parameter(Mandatory=$true, Position=0, ValueFromPipeline=$true)] [string]$Input ) process { $subnetMaskRegex = '^(0|128|192|224|240|248|252|254|255)\.0\.0\.0$|^(255\.(0|128|192|224|240|248|252|254|255)\.0\.0)$|^(255\.255\.(0|128|192|224|240|248|252|254|255)\.0)$|^(255\.255\.255\.(0|128|192|224|240|248|252|254|255))$' $ipAddressRegex = '^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$' $parts = $Input -split '\s+' if ($parts.Count -eq 2) { # IP address and subnet mask $ipAddress = $parts[0] $subnetMask = $parts[1] if ($ipAddress -match $ipAddressRegex -and $subnetMask -match $subnetMaskRegex) { $cidr = Convert-AbrFgtSubnetMaskToCIDR -SubnetMask $subnetMask Write-PScriboMessage "Converted IP address $ipAddress and subnet mask $subnetMask to CIDR $ipAddress/$cidr." return "$ipAddress/$cidr" } } elseif ($parts.Count -eq 1) { if ($Input -match $subnetMaskRegex) { $cidr = Convert-AbrFgtSubnetMaskToCIDR -SubnetMask $Input Write-PScriboMessage "Converted subnet mask $Input to CIDR /$cidr." return "/$cidr" } elseif ($Input -match $ipAddressRegex) { Write-PScriboMessage "Input is a single IP address, assuming /32 CIDR." return "$Input/32" } elseif ($Input -match "^$ipAddressRegex/\d{1,2}$") { Write-PScriboMessage "Input is already in CIDR notation." return $Input } } Write-Error "Invalid input format. Expected IP address with subnet mask, IP address, subnet mask, or IP address in CIDR notation." return $Input } } function Convert-AbrFgtSubnetMaskToCIDR { <# .SYNOPSIS Used by As Built Report to convert subnet mask to CIDR prefix. .DESCRIPTION Converts subnet mask to CIDR prefix number for Fortinet FortiGate As Built Report. .NOTES Version: 0.1.0 Author: Alexis La Goutte Twitter: @alagoutte Github: alagoutte Credits: Iain Brighton (@iainbrighton) - PScribo module .EXAMPLE Convert-AbrFgtSubnetMaskToCIDR "255.255.255.0" Returns: 24 .EXAMPLE Convert-AbrFgtSubnetMaskToCIDR "255.255.0.0" Returns: 16 .EXAMPLE Convert-AbrFgtSubnetMaskToCIDR "255.255.255.252" Returns: 30 .LINK https://github.com/AsBuiltReport/AsBuiltReport.Fortinet.FortiGate #> [CmdletBinding()] [OutputType([System.String])] param ( [Parameter(Mandatory=$true)] [string]$SubnetMask ) $cidr = [System.Net.IPAddress]::Parse($SubnetMask).GetAddressBytes() | ForEach-Object { [Convert]::ToString($_, 2).PadLeft(8, '0') } | ForEach-Object { $_.ToCharArray() } | Where-Object { $_ -eq '1' } | Measure-Object | Select-Object -ExpandProperty Count if ($cidr -lt 0 -or $cidr -gt 32) { Write-Error "Invalid CIDR value. Expected a value between 0 and 32, but got $cidr." return $SubnetMask } return $cidr } |