validate.func

#!/usr/bin/env bash
# Copyright (c) 2021-2026 community-scripts ORG
# License: MIT | https://raw.githubusercontent.com/community-scripts/core/main/LICENSE

# ==============================================================================
# VALIDATE.FUNC - VALUE CHECKS SHARED BY EVERY PLATFORM
# ==============================================================================
#
# Whether an MTU is in range or a MAC looks like a MAC does not depend on
# whether the host runs Proxmox VE or Incus. Only what the value is then
# formatted into does — ",mtu=1500" on one side, `incus config device set` on
# the other — so the checks live here and the formatting stays in the backends.
#
# Every function takes the raw value, returns 0 when it is acceptable, and
# treats empty as acceptable: "leave blank for the default" is a valid answer
# everywhere, and a caller that needs a value checks for empty itself.
#
# No dependencies, no output. Sourced by the container UI and by both VM paths.
#
# ==============================================================================

[[ -n "${_VALIDATE_FUNC_LOADED:-}" ]] && return
_VALIDATE_FUNC_LOADED=1

# ------------------------------------------------------------------------------
# validate_mac_address()
#
# - Validates MAC address format (XX:XX:XX:XX:XX:XX)
# - Empty value is allowed (auto-generate)
# - Returns 0 if valid, 1 if invalid
# ------------------------------------------------------------------------------
validate_mac_address() {
  local mac="$1"
  [[ -z "$mac" ]] && return 0
  if [[ ! "$mac" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
    return 1
  fi
  return 0
}

# ------------------------------------------------------------------------------
# validate_vlan_tag()
#
# - Validates VLAN tag (1-4094)
# - Empty value is allowed (no VLAN)
# - Returns 0 if valid, 1 if invalid
# ------------------------------------------------------------------------------
validate_vlan_tag() {
  local vlan="$1"
  [[ -z "$vlan" ]] && return 0
  if ! [[ "$vlan" =~ ^[0-9]+$ ]] || ((vlan < 1 || vlan > 4094)); then
    return 1
  fi
  return 0
}

# ------------------------------------------------------------------------------
# validate_mtu()
#
# - Validates MTU size (576-65520, common values: 1500, 9000)
# - Empty value is allowed (default 1500)
# - Returns 0 if valid, 1 if invalid
#
# The upper bound is the Proxmox one, not the Linux one. `qm set`/`pct set`
# reject anything above 65520, so accepting up to 65535 here would let a prompt
# take a value the API then refuses — a check that passes and an install that
# fails is worse than a check that is slightly strict.
# ------------------------------------------------------------------------------
validate_mtu() {
  local mtu="$1"
  [[ -z "$mtu" ]] && return 0
  if ! [[ "$mtu" =~ ^[0-9]+$ ]] || ((mtu < 576 || mtu > 65520)); then
    return 1
  fi
  return 0
}