udhcp: optional support for non-standard DHCP ports (+300 bytes when selected)

[oweals/busybox.git] / networking / udhcp / Config.in

diff --git a/networking/udhcp/Config.in b/networking/udhcp/Config.in
index 76b078001bd458e1b4457d50d392d49a229800d9..ff0e4e2ae81663b1bf2fad7c91ba65d1729cb369 100644 (file)
--- a/networking/udhcp/Config.in
+++ b/networking/udhcp/Config.in
@@ -54,6 +54,23 @@ config APP_UDHCPC
 
          See http://udhcp.busybox.net for further details.
 
+config FEATURE_UDHCPC_ARPING
+       bool "Ask udhcpc to verify that the offered address is free, using arpping"
+       default y
+       depends on APP_UDHCPC
+       help
+         If selected, udhcpc will use arpping to make sure the offered address
+         is really available. The client will DHCPDECLINE the offer if the
+         address is in use, and restart the discover process.
+
+config FEATURE_UDHCP_PORT
+       bool "Enable '-P port' option for udhcpd and udhcpc"
+       default n
+       depends on APP_UDHCPD || APP_UDHCPC
+       help
+         At the cost of ~300 bytes, enables -P port option.
+         This feature is typically not needed.
+
 config FEATURE_UDHCP_DEBUG
        bool "Compile udhcp with noisy debugging messages"
        default n
@@ -72,3 +89,26 @@ config FEATURE_RFC3397
        help
          If selected, both client and server will support passing of domain
          search lists via option 119, specified in RFC3397.
+
+config UDHCPC_SLACK_FOR_BUGGY_SERVERS
+       int "DHCP options slack buffer size"
+       default 80
+       range 0 924
+       depends on APP_UDHCPD || APP_UDHCPC
+       help
+         Some buggy DHCP servers will send DHCP offer packets with option
+         field larger than we expect (which might also be considered a
+         buffer overflow attempt). These packets are normally discarded.
+         If circumstances beyond your control force you to support such
+         servers, this may help. The upper limit (924) makes dhcpc accept
+         even 1500 byte packets (maximum-sized ethernet packets).
+
+         This options does not make dhcp[cd] emit non-standard
+         sized packets.
+
+         Known buggy DHCP servers:
+         3Com OfficeConnect Remote 812 ADSL Router:
+           seems to confuse maximum allowed UDP packet size with
+           maximum size of entire IP packet, and sends packets which are
+           28 bytes too large.
+         Seednet (ISP) VDSL: sends packets 2 bytes too big.