haproxy analog set_real_ip_from in nginx

i'm using web application firewall, what has multiple ip range. How i can set it on my haproxy config?

current config

frontend front
  mode http
  log global
  bind *:80 alpn h2,http/1.1
  bind *:443 alpn h2,http/1.1 ssl crt /etc/ssl/cert.perm
  http-request redirect scheme https code 301 unless { ssl_fc }
  http-request set-header X-Real-IP %[src]
  option forwardfor header X-Real-IP
  default_backend back

backend back
  mode http
  log global
  server backend 10.3.1.1:8443 check ssl verify none