1dhcpcd - DHCP client daemon 2Copyright (c) 2006-2015 Roy Marples <roy@marples.name> 3 4 5Installation 6------------ 7./configure; make; make install 8man dhcpcd for command line options 9man dhcpcd.conf for configuration options 10man dhcpcd-run-hooks to learn how to hook scripts into dhcpcd events 11 12 13Notes 14----- 15If you're cross compiling you may need set the platform if OS is different 16from the host. 17--target=sparc-sun-netbsd5.0 18 19If you're building for an MMU-less system where fork() does not work, you 20should ./configure --disable-fork. 21This also puts the --no-background flag on and stops the --background flag 22from working. 23 24You can change the default dirs with these knobs. 25For example, to satisfy FHS compliance you would do this:- 26./configure --libexecdir=/lib/dhcpcd dbdir=/var/lib/dhcpcd 27 28We now default to using -std=c99. For 64-bit linux, this always works, but 29for 32-bit linux it requires either gnu99 or a patch to asm/types.h. 30Most distros patch linux headers so this should work fine. 31linux-2.6.24 finally ships with a working 32-bit header. 32If your linux headers are older, or your distro hasn't patched them you can 33set CSTD=gnu99 to work around this. 34 35Some BSD systems do not allow the manipulation of automatically added subnet 36routes. You can find discussion here: 37 http://mail-index.netbsd.org/tech-net/2008/12/03/msg000896.html 38BSD systems where this has been fixed or is known to work are: 39 NetBSD-5.0 40 FreeBSD-10.0 41 42Some BSD systems protect against IPv6 NS/NA messages by ensuring that the 43source address matches a prefix on the recieved by a RA message. 44This is an error as the correct check is for on-link prefixes as the 45kernel may not be handling RA itself. 46BSD systems where this has been fixed or is known to work are: 47 NetBSD-7.0 48 OpenBSD-5.0 49 patch submitted against FreeBSD-10.0 50 51Some BSD systems do not announce IPv6 address flag changes, such as 52IN6_IFF_TENTATIVE, IN6_IFF_DUPLICATED, etc. On these systems, 53dhcpcd will poll a freshly added address until either IN6_IFF_TENTATIVE is 54cleared or IN6_IFF_DUPLICATED is set and take action accordingly. 55BSD systems where this has been fixed or is known to work are: 56 NetBSD-7.0 57 58Some BSD systems do not announce cached neighbour route changes based 59on reachability to userland. For such systems, IPv6 routers will always 60be assumed to be reachable until they either stop being a router or expire. 61BSD systems where this has been fixed or is known to work are: 62 NetBSD-7.99.3 63 64Linux prior to 3.17 won't allow userland to manage IPv6 temporary addresses. 65Either upgrade or don't allow dhcpcd to manage the RA, 66so don't set either "ipv6ra_own" or "slaac private" in dhcpcd.conf if you 67want to have working IPv6 temporary addresses. 68SLAAC private addresses are just as private, just stable. 69 70ArchLinux presently sanitises all kernel headers to the latest version 71regardless of the version for your CPU. As such, Arch presently ships a 723.12 kernel with 3.17 headers which claim that it suppors temporary address 73management and no automatic prefix route generation, both of which are 74obviously false. You will have to patch support either in the kernel or 75out of the headers (or dhcpcd itself) to have correct operation. 76 77We try and detect how dhcpcd should interact with system services at runtime. 78If we cannot auto-detect how do to this, or it is wrong then 79you can change this by passing shell commands to --serviceexists, 80--servicecmd and optionally --servicestatus to ./configure or overriding 81the service variables in a hook. 82 83Some systems have /dev management systems and some of these like to rename 84interfaces. As this system would listen in the same way as dhcpcd to new 85interface arrivals, dhcpcd needs to listen to the /dev management sytem 86instead of the kernel. However, if the /dev management system breaks, stops 87working, or changes to a new one, dhcpcd should still try and continue to work. 88To facilitate this, dhcpcd allows a plugin to load to instruct dhcpcd when it 89can use an interface. As of the time of writing only udev support is included. 90You can disable this with --without-dev, or without-udev 91 92To shrink dhcpcd you can disable IPv4 or IPv6: 93 --disable-inet 94 --disable-inet6 95 96You can also move the embedded extended configuration from the dhcpcd binary 97to an external file (LIBEXECDIR/dhcpcd-definitions.conf) 98 --disable-embedded 99If dhcpcd cannot load this file at runtime, dhcpcd will work but will not be 100able to decode any DHCP/DHCPv6 options that are not defined by the user 101in /etc/dhcpcd.conf. 102 103To prepare dhcpcd for import into a platform source tree (like NetBSD) 104you can use the make import target to create /tmp/dhcpcd-$version and 105populate it with all the source files and hooks needed. 106In this instance, you may wish to disable some configured tests when 107the binary has to run on older versions which lack support, such as getline. 108./configure --without-getline 109 110Building for distribution (ie making a dhcpcd source tarball) now requires 111gmake-4 or any BSD make. 112 113 114Hooks 115----- 116Not all the hooks in dhcpcd-hooks are installed by default. 117By default we install 01-test, 02-dump, 10-mtu, 10-wpa_supplicant, 11815-timezone, 20-resolv.conf, 29-lookup-hostname and 30-hostname. 119The default dhcpcd.conf disables the lookup-hostname hook by default. 120The configure program attempts to find hooks for systems you have installed. 121To add more simply 122./configure -with-hook=ntp.conf 123 124Some system services expose the name of the service we are in, 125by default dhcpcd will pick RC_SVCNAME from the environment. 126You can override this in CPPFLAGS+= -DRC_SVCNAME="YOUR_SVCNAME". 127This is important because dhcpcd will scrub the environment aside from $PATH 128before running hooks. 129This variable could be used to facilitate service re-entry so this chain could 130happen in a custom OS hook: 131 dhcpcd service marked inactive && dhcpcd service starts 132 dependant services are not started because dhcpcd is inactive (not stopped) 133 dhcpcd hook tests $if_oneup && $if_ipwaited 134 if true, mark the dhcpcd service as started and then start dependencies 135 if false and the dhcpcd service was previously started, mark as inactive and 136 stop any dependant services. 137 138 139Compatibility 140------------- 141dhcpcd-5.0 is only fully command line compatible with dhcpcd-4.0 142For compatibility with older versions, use dhcpcd-4.0 143 144 145ChangeLog 146--------- 147We no longer supply a ChangeLog. 148However, you're more than welcome to read the commit log at 149http://roy.marples.name/projects/dhcpcd/timeline/ 150