2 # For a description of the syntax of this configuration file,
3 # see docs/Kconfig-language.txt.
11 udhcpd is a DHCP server geared primarily toward embedded systems,
12 while striving to be fully functional and RFC compliant.
14 config FEATURE_UDHCPD_BASE_IP_ON_MAC
15 bool "Select IP address based on client MAC"
19 If selected, udhcpd will base its selection of IP address to offer
20 on the client's hardware address. Otherwise udhcpd uses the next
21 consecutive free address.
23 This reduces the frequency of IP address changes for clients
24 which let their lease expire, and makes consecutive DHCPOFFERS
25 for the same client to (almost always) contain the same
28 config FEATURE_UDHCPD_WRITE_LEASES_EARLY
29 bool "Rewrite lease file at every new acknowledge"
33 If selected, udhcpd will write a new file with leases every
34 time a new lease has been accepted, thus eliminating the need
35 to send SIGUSR1 for the initial writing or updating. Any timed
36 rewriting remains undisturbed.
38 config DHCPD_LEASES_FILE
39 string "Absolute path to lease file"
40 default "/var/lib/misc/udhcpd.leases"
43 udhcpd stores addresses in a lease file. This is the absolute path
44 of the file. Normally it is safe to leave it untouched.
47 bool "dumpleases (5.1 kb)"
50 dumpleases displays the leases written out by the udhcpd.
51 Lease times are stored in the file by time remaining in lease, or
52 by the absolute time that it expires in seconds from epoch.
55 bool "dhcprelay (5.2 kb)"
58 dhcprelay listens for DHCP requests on one or more interfaces
59 and forwards these requests to a different interface or DHCP
67 udhcpc is a DHCP client geared primarily toward embedded systems,
68 while striving to be fully functional and RFC compliant.
70 The udhcp client negotiates a lease with the DHCP server and
71 runs a script when a lease is obtained or lost.
73 config FEATURE_UDHCPC_ARPING
74 bool "Verify that the offered address is free, using ARP ping"
78 If selected, udhcpc will send ARP probes and make sure
79 the offered address is really not in use by anyone. The client
80 will DHCPDECLINE the offer if the address is in use,
81 and restart the discover process.
83 config FEATURE_UDHCPC_SANITIZEOPT
84 bool "Do not pass malformed host and domain names"
88 If selected, udhcpc will check some options (such as option 12 -
89 hostname) and if they don't look like valid hostnames
90 (for example, if they start with dash or contain spaces),
91 they will be replaced with string "bad" when exporting
94 config UDHCPC_DEFAULT_SCRIPT
95 string "Absolute path to config script"
96 default "/usr/share/udhcpc/default.script"
97 depends on UDHCPC || UDHCPC6
99 This script is called after udhcpc receives an answer. See
100 examples/udhcp for a working example. Normally it is safe
101 to leave this untouched.
103 # udhcpc6 config is inserted here:
106 comment "Common options for DHCP applets"
107 depends on UDHCPD || UDHCPC || UDHCPC6 || DHCPRELAY
109 config FEATURE_UDHCP_PORT
110 bool "Enable '-P port' option for udhcpd and udhcpc"
112 depends on UDHCPD || UDHCPC || UDHCPC6
114 At the cost of ~300 bytes, enables -P port option.
115 This feature is typically not needed.
118 int "Maximum verbosity level (0..9)"
121 depends on UDHCPD || UDHCPC || UDHCPC6 || DHCPRELAY
123 Verbosity can be increased with multiple -v options.
124 This option controls how high it can be cranked up.
126 Bigger values result in bigger code. Levels above 1
127 are very verbose and useful for debugging only.
129 config UDHCPC_SLACK_FOR_BUGGY_SERVERS
130 int "DHCP options slack buffer size"
133 depends on UDHCPD || UDHCPC
135 Some buggy DHCP servers send DHCP offer packets with option
136 field larger than we expect (which might also be considered a
137 buffer overflow attempt). These packets are normally discarded.
138 If circumstances beyond your control force you to support such
139 servers, this may help. The upper limit (924) makes udhcpc accept
140 even 1500 byte packets (maximum-sized ethernet packets).
142 This option does not make udhcp[cd] emit non-standard
145 Known buggy DHCP servers:
146 3Com OfficeConnect Remote 812 ADSL Router:
147 seems to confuse maximum allowed UDP packet size with
148 maximum size of entire IP packet, and sends packets
149 which are 28 bytes too large.
150 Seednet (ISP) VDSL: sends packets 2 bytes too large.
152 config FEATURE_UDHCP_RFC3397
153 bool "Support RFC 3397 domain search options"
155 depends on UDHCPD || UDHCPC
157 If selected, both client and server will support passing of domain
158 search lists via option 119, specified in RFC 3397,
159 and SIP servers option 120, specified in RFC 3361.
161 config FEATURE_UDHCP_8021Q
162 bool "Support 802.1Q VLAN parameters options"
164 depends on UDHCPD || UDHCPC
166 If selected, both client and server will support passing of VLAN
167 ID and priority via options 132 and 133 as per 802.1Q.