Define the IPv4 NTP server setting to simplify the use of a
DHCP-provided NTP server in scripts, using e.g.
#!ipxe
dhcp
ntp ${ntp}
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When a DHCP transaction does not result in the registration of a new
"proxydhcp" or "pxebs" settings block, any existing settings blocks
are currently left unaltered.
This can cause surprising behaviour. For example: when chainloading
iPXE, the "proxydhcp" and "pxebs" settings blocks may be prepopulated
using cached values from the previous PXE bootloader. If iPXE
performs a subsequent DHCP request, then the DHCP or ProxyDHCP servers
may choose to respond differently to iPXE. The response may choose to
omit the ProxyDHCP or PXEBS stages, in which case no new "proxydhcp"
or "pxebs" settings blocks may be registered. This will result in
iPXE using a combination of both old and new DHCP responses.
Fix by assuming that a successful DHCPACK effectively acquires
ownership of the "proxydhcp" and "pxebs" settings blocks, and that any
existing settings blocks should therefore be unregistered.
Reported-by: Henry Tung <htung@palantir.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
RFC 2131 leaves undefined the behaviour of the client in response to a
DHCPNAK that comes from a server other than the selected DHCP server.
A substantial amount of online documentation suggests using multiple
independent DHCP servers with non-overlapping ranges in the same
subnet in order to provide some minimal redundancy. Experimentation
shows that in this setup, at least ISC dhcpd will send a DHCPNAK in
response to the client's DHCPREQUEST for an address that is not within
the range defined on that server. (Since the requested address does
lie within the subnet defined on that server, this will happen
regardless of the "authoritative" parameter.) The client will
therefore receive a DHCPACK from the selected DHCP server along with
one or more DHCPNAKs from each of the non-selected DHCP servers.
Filter out responses from non-selected DHCP servers before checking
for a DHCPNAK, so that these arguably spurious DHCPNAKs will not cause
iPXE to return to the discovery state.
Continue to check for DHCPNAK before filtering out responses for
non-selected lease addresses, since experimentation shows that the
DHCPNAK will usually have an empty yiaddr field.
Reported-by: Anders Blomdell <anders.blomdell@control.lth.se>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Move the platform-specific DHCP client architecture definitions to
header files of the form <ipxe/$(PLATFORM)/dhcparch.h>. This
simplifies the directory structure and allows the otherwise unused
arch/$(ARCH)/include/$(PLATFORM) to be removed from the include
directory search path, which avoids the confusing situation in which a
header file may potentially be accessed through more than one path.
For Linux userspace binaries on any architecture, use the EFI values
for that architecture by delegating to the EFI header file. This
avoids the need to explicitly select values for Linux userspace
binaries for each architecture.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The network device index currently serves two purposes: acting as a
sequential index for network device names ("net0", "net1", etc), and
acting as an opaque unique integer identifier used in socket address
scope IDs.
There is no particular need for these usages to be linked, and it can
lead to situations in which devices are named unexpectedly. For
example: if a system has two network devices "net0" and "net1", a VLAN
is created as "net1-42", and then a USB NIC is connected, then the USB
NIC will be named "net3" rather than the expected "net2" since the
VLAN device "net1-42" will have consumed an index.
Separate the usages: rename the "index" field to "scope_id" (matching
its one and only use case), and assign the name without reference to
the scope ID by finding the first unused name. For consistency,
assign the scope ID by similarly finding the first unused scope ID.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We currently define the active DNS server as a global variable. All
queries will start by attempting to contact the active DNS server, and
the active DNS server will be changed only if we fail to get a
response. This effectively treats the DNS server list as expressing a
weak preference ordering: we will try servers in order, but once we
have found a working server we will stick with that server for as long
as it continues to respond to queries.
Some sites are misconfigured to hand out DNS servers that do not have
a consistent worldview. For example: the site may hand out two DNS
server addresses, the first being an internal DNS server (which is
able to resolve names in private DNS domains) and the second being a
public DNS server such as 8.8.8.8 (which will correctly return
NXDOMAIN for any private DNS domains). This type of configuration is
fundamentally broken and should never be used, since any DNS resolver
performing a query for a name within a private DNS domain may obtain a
spurious NXDOMAIN response for a valid private DNS name.
Work around these broken configurations by treating the DNS server
list as expressing a strong preference ordering, and always starting
DNS queries from the first server in the list (rather than maintaining
a global concept of the active server). This will have the debatable
benefit of converting permanent spurious NXDOMAIN errors into
transient spurious NXDOMAIN errors, which can at least be worked
around at a higher level (e.g. by retrying a download in a loop within
an iPXE script).
The cost of always starting DNS queries from the first server in the
list is a slight delay introduced when the first server is genuinely
unavailable. This should be negligible in practice since DNS queries
are relatively infrequent and the failover expiry time is short.
Treating the DNS server list as a preference ordering is permitted by
the language of RFC 2132, which defines DHCP option 6 as a list in
which "[DNS] servers SHOULD be listed in order of preference". No
specification defines a precise algorithm for how this preference
order should be applied in practice: this new approach seems as good
as any.
Requested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Handle a DHCPNAK by returning to the discovery state to allow iPXE to
attempt to obtain a replacement IPv4 address.
Reuse the existing logic for deferring discovery when the link is
blocked: this avoids hammering a misconfigured DHCP server with a
non-stop stream of requests and allows the DHCP process to eventually
time out and fail.
Originally-implemented-by: Blake Rouse <blake.rouse@canonical.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The DNS server list is currently printed as a debug message whenever
settings are applied. This can result in some very noisy debug logs
when a script makes extensive use of settings.
Move the DNS server list debug messages to DBGLVL_EXTRA.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide some visibility into the turnaround times on both client and
server sides as perceived by iPXE, to assist in debugging inexplicably
slow TFTP transfers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Continue to transmit DHCPDISCOVER while waiting for a blocked link, in
order to support mechanisms such as Cisco MAC Authentication Bypass
that require repeated transmission attempts in order to trigger the
action that will result in the link becoming unblocked.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When no response is obtained from the first configured DNS server,
fall back to attempting the other configured servers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Eliminate an unnecessary variable-length stack allocation and memory
copy by allowing TFTP option processors to modify the option string
in-place.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a settings applicator to modify netdev->max_pkt_len in
response to changes to the "mtu" setting (DHCP option 26).
Note that as with MAC address changes, drivers are permitted to
completely ignore any changes in the MTU value. The net result will
be that iPXE effectively uses the smaller of either the hardware
default MTU or the software configured MTU.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Use the IPv6 settings to construct the routing table, in a matter
analogous to the construction of the IPv4 routing table.
This allows for manual assignment of IPv6 addresses via e.g.
set net0/ip6 2001:ba8:0:1d4::6950:5845
set net0/len6 64
set net0/gateway6 fe80::226:bff:fedd:d3c0
The prefix length ("len6") may be omitted, in which case a default
prefix length of 64 will be assumed.
Multiple IPv6 addresses may be assigned manually by implicitly
creating child settings blocks. For example:
set net0/ip6 2001:ba8:0:1d4::6950:5845
set net0.ula/ip6 fda4:2496:e992::6950:5845
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A reasonable user expectation is that ${net0/ip6} should show the
"highest-priority" of the IPv6 addresses, even when multiple IPv6
addresses are active. The expected order of priority is likely to be
manually-assigned addresses first, then stateful DHCPv6 addresses,
then SLAAC addresses, and lastly link-local addresses.
Using ${priority} to enforce an ordering is undesirable since that
would affect the priority assigned to each of the net<N> blocks as a
whole, so use the sibling ordering capability instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Originally-implemented-by: Hannes Reinecke <hare@suse.de>
Originally-implemented-by: Marin Hannache <git@mareo.fr>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The settings scope ipv6_scope refers specifically to IPv6 settings
that have a corresponding DHCPv6 option. Rename to dhcpv6_scope to
more accurately reflect this purpose.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The vendor class identifier strings in DHCP_ARCH_VENDOR_CLASS_ID are
out of sync with the (correct) client architecture values in
DHCP_ARCH_CLIENT_ARCHITECTURE.
Fix by removing all definitions of DHCP_ARCH_VENDOR_CLASS_ID, and
instead generating the vendor class identifier string automatically
based on DHCP_ARCH_CLIENT_ARCHITECTURE and DHCP_ARCH_CLIENT_NDI.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
RFC3315 defines DHCPv6 option 16 (vendor class identifier) but does
not define any direct relationship with the roughly equivalent DHCPv4
option 60.
The PXE specification predates IPv6, and the UEFI specification is
expectedly vague on the subject. Examination of the reference EDK2
codebase suggests that the DHCPv6 vendor class identifier will be
formatted in accordance with RFC3315, using a single vendor-class-data
item in which the opaque-data field is the string as would appear in
DHCPv4 option 60.
RFC3315 requires the vendor class identifier to specify an IANA
enterprise number, as a way of disambiguating the vendor-class-data
namespace. The EDK2 code uses the value 343, described as:
// TODO: IANA TBD: temporarily using Intel's
Since this "TODO" has been present since at least 2010, it is probably
safe to assume that it has now become a de facto standard.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
RFC5970 defines DHCPv6 options 61 (client system architecture type)
and 62 (client network interface identifier), with contents equivalent
to DHCPv4 options 93 and 94 respectively.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
DHCPv4 and DHCPv6 share some values in common for the architecture-
specific options (such as the client system architecture type), but
use different encapsulations: DHCPv4 has a single byte for the option
length while DHCPv6 has a 16-bit field for the option length.
Move the containing DHCP_OPTION() and related wrappers from the
individual dhcp_arch.h files to dhcp.c, thus allowing for the
architecture-specific values to be reused in dhcpv6.c.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TFTP URIs are intrinsically problematic, since:
- TFTP servers may use either normal slashes or backslashes as a
directory separator,
- TFTP servers allow filenames to be specified using relative paths
(with no initial directory separator),
- TFTP filenames present in a DHCP filename field may use special
characters such as "?" or "#" that prevent parsing as a generic URI.
As of commit 7667536 ("[uri] Refactor URI parsing and formatting"), we
have directly constructed TFTP URIs from DHCP next-server and filename
pairs, avoiding the generic URI parser. This eliminated the problems
related to special characters, but indirectly made it impossible to
parse a "tftp://..." URI string into a TFTP URI with a non-absolute
path.
Re-introduce the convention of requiring an extra slash in a
"tftp://..." URI string in order to specify a TFTP URI with an initial
slash in the filename. For example:
tftp://192.168.0.1/boot/pxelinux.0 => RRQ "boot/pxelinux.0"
tftp://192.168.0.1//boot/pxelinux.0 => RRQ "/boot/pxelinux.0"
This is ugly, but there seems to be no other sensible way to provide
the ability to specify all possible TFTP filenames.
A side-effect of this change is that format_uri() will no longer add a
spurious initial "/" when formatting a relative URI string. This
improves the console output when fetching an image specified via a
relative URI.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
For historical reasons, iPXE sets the current working URI to the root
of the TFTP server whenever the TFTP server address is changed. This
was originally implemented in the hope of allowing a DHCP-provided
TFTP filename to be treated simply as a relative URI. This usage
turns out to be impractical since DHCP-provided TFTP filenames may
include characters which would have special significance to the URI
parser, and so the DHCP next-server+filename combination is now
handled by the dedicated pxe_uri() function instead.
The practice of setting the current working URI to the root of the
TFTP server is potentially helpful for interactive uses of iPXE,
allowing a user to type e.g.
iPXE> dhcp
Configuring (net0 52:54:00:12:34:56)... ok
iPXE> chain pxelinux.0
and have the URI "pxelinux.0" interpreted as being relative to the
root of the TFTP server provided via DHCP.
The current implementation of tftp_apply_settings() has an unintended
flaw. When the "dhcp" command is used to renew a DHCP lease (or to
pick up potentially modified DHCP options), the old settings block
will be unregistered before the new settings block is registered.
This causes tftp_apply_settings() to believe that the TFTP server has
been changed twice (to 0.0.0.0 and back again), and so the current
working URI will always be set to the root of the TFTP server, even if
the DHCP response provides exactly the same TFTP server as previously.
Fix by doing nothing in tftp_apply_settings() whenever there is no
TFTP server address.
Debugged-by: Andrew Widdersheim <awiddersheim@inetu.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
For switches which remain permanently in the non-forwarding state (or
which erroneously report a non-forwarding state), ensure that iPXE
will eventually give up waiting for the link to become unblocked.
Originally-fixed-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
If we detect (via STP) that a switch port is in a non-forwarding
state, then the link is marked as being temporarily blocked and DHCP
discovery will be deferred until the link becomes unblocked.
The timer used to decide when to give up waiting for ProxyDHCPOFFERs
is currently based on the time that DHCP discovery was started, and
makes no allowances for any time spent waiting for the link to become
unblocked. Consequently, if STP is used then the timeout for
ProxyDHCPOFFERs becomes essentially zero.
Fix by resetting the recorded start time whenever DHCP discovery is
deferred due to a blocked link.
Debugged-by: Sebastian Roth <sebastian.roth@zoho.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We attempt to mimic the behaviour of Intel's PXE ROM by skipping the
separate ProxyDHCPREQUEST if the ProxyDHCPOFFER already contains a
boot filename or a PXE boot menu.
Experimentation reveals that Intel's PXE ROM will also check for a
non-empty next-server address alongside the boot filename. Update our
test to match this behaviour.
Reported-by: Wissam Shoukair <wissams@mellanox.com>
Tested-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some ProxyDHCP servers and PXE boot servers do not specify a DHCP
server identifier via option 54. We currently work around this in a
variety of ad-hoc ways:
- if a ProxyDHCPACK has no server identifier then we treat it as
having the correct server identifier,
- if a boot server ACK has no server identifier then we use the
packet's source IP address as the server identifier.
Introduce the concept of a DHCP server pseudo-identifier, defined as
being:
- the server identifier (option 54), or
- if there is no server identifier, then the next-server address
(siaddr),
- if there is no server identifier or next-server address, then the
DHCP packet's source IP address.
Use the pseudo-identifier in place of the server identifier when
handling ProxyDHCP and PXE boot server responses.
Originally-fixed-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
If the link is blocked (e.g. due to a Spanning Tree Protocol port not
yet forwarding packets) then defer DHCP discovery until the link
becomes unblocked.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
These files cannot be automatically relicensed by util/relicense.pl
since they either contain unusual but trivial contributions (such as
the addition of __nonnull function attributes), or contain lines
dating back to the initial git revision (and so require manual
knowledge of the code's origin).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE uses DHCP timeouts loosely based on values recommended by the
specification, but often abbreviated to reduce timeouts for reliable
and/or simple network topologies. Extract the DHCP timing parameters
to config/dhcp.h and document them. The resulting default iPXE
behavior is exactly the same, but downstreams are now afforded the
opportunity to implement spec-compliant behavior via config file
overrides.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fetching the TFTP file size is currently implemented via a custom
"tftpsize://" protocol hack. Generalise this approach to instead
close the TFTP connection whenever the parent data-transfer interface
is closed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As of commit 03f0c23 ("[ipoib] Expose Ethernet-compatible eIPoIB
link-layer addresses and headers"), all link layers have used
addresses which fit within the DHCP chaddr field. The dhcp_chaddr()
function was therefore made obsolete by this commit, but was
accidentally left present (though unused) in the source code.
Remove the dhcp_chaddr() function and the only remaining use of it,
unnecessarily introduced in commit 08bcc0f ("[dhcp] Check for matching
chaddr in received DHCP packets").
Reported-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
On large networks a DHCP XID collision is possible. Fix by explicitly
checking the chaddr in received DHCP packets.
Originally-fixed-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Setting sin6_scope_id to a non-zero value will cause the check against
the "empty socket address" in udp_demux() to fail, and incoming DHCPv6
responses on interfaces other than net0 will be rejected with a
spurious "No UDP connection listening on port 546" error.
The transmitting network device is specified via the destination
address, not the source address. Fix by simply not setting
sin6_scope_id on the client socket address.
Reported-by: Anton D. Kachalov <mouse@yandex-team.ru>
Tested-by: Anton D. Kachalov <mouse@yandex-team.ru>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Avoid generating syntactically invalid log messages by ensuring that
invalid characters are not present in the hostname. In particular,
ensure that any whitespace is stripped, since whitespace functions as
a field separator for syslog messages.
Reported-by: Alex Davies <adavies@jumptrading.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Cornelius Hoffmann
Michael Brown
Alex Williamson