{
  socket_type = stream
  server = /usr/sbin/saned
  protocol = tcp
  user = root
  group = root
  wait = no
  disable = no
}

root@bill:/etc/sane.d# scanimage -L

No scanners were identified. If you were expecting something different,
check that the scanner is plugged in, turned on and detected by the
sane-find-scanner tool (if appropriate). Please read the documentation
which came with this software (README, FAQ, manpages).

Logread on openwrt gives me: 
Jan  1 01:52:16 OpenWrt daemon.debug xinetd[624]: Reading included configuration file: /etc/xinetd.d/sane [file=/etc/xinetd.conf] [line=6]
Jan  1 01:52:16 OpenWrt daemon.notice xinetd[624]: xinetd Version 2.3.13 started with loadavg options compiled in.
Jan  1 01:52:16 OpenWrt daemon.notice xinetd[624]: Started working: 1 available service
Jan  1 01:52:27 OpenWrt daemon.debug saned[626]: saned from sane-backends 1.0.17 ready 
Jan  1 01:52:27 OpenWrt daemon.debug saned[626]: check_host: access by remote host: 192.168.20.216 
Jan  1 01:52:30 OpenWrt daemon.debug saned[626]: init: access granted to tom@192.168.20.216 
Jan  1 01:52:30 OpenWrt daemon.debug saned[626]: quit: exiting

[saned] main: starting debug mode (level 256)
[saned] main: trying to get port for service `sane' (getservbyname)
[saned] main: port is 6566
[saned] main: socket ()
[saned] main: setsockopt ()
[saned] main: bind ()
[saned] main: listen ()
[saned] main: waiting for control connection
[saned] saned from sane-backends 1.0.17 ready
[saned] check_host: access by remote host: 192.168.20.216
[saned] check_host: remote host is not IN_LOOPBACK
[saned] check_host: local hostname: OpenWrt
[saned] check_host: local hostname (from DNS): server
[saned] check_host: local host address (from DNS): 192.168.20.1
[saned] check_host: remote host doesn't have same addr as local
[saned] check_host: opening config file: /etc/hosts.equiv
[saned] check_host: can't open config file: /etc/hosts.equiv (No such file or directory)
[saned] check_host: opening config file: saned.conf
[saned] check_host: config file line: `#'
[saned] check_host: config file line: `# saned.conf'
[saned] check_host: config file line: `#'
[saned] check_host: config file line: `# The contents of the saned.conf  file  is  a  list  of  host  names,  IP'
[saned] check_host: config file line: `# addresses or IP subnets (CIDR notation) that are permitted to use local'
[saned] check_host: config file line: `# SANE devices. IPv6 addresses must be enclosed in brackets,  and  should'
[saned] check_host: config file line: `# always  be specified in their compressed form.'
[saned] check_host: config file line: `#'
[saned] check_host: config file line: `# The hostname matching is not case-sensitive.'
[saned] check_host: config file line: `#'
[saned] check_host: config file line: `#scan-client.somedomain.firm'
[saned] check_host: config file line: `192.168.20.0/24'
[saned] check_host: subnet with base IP = 192.168.20.0, CIDR netmask = 24
[saned] check_host: access granted from IP address 192.168.20.216 (in subnet 192.168.20.0/24)
[saned] init: access granted