[netdevice] Limit MTU by hardware maximum frame length
Separate out the concept of "hardware maximum supported frame length"
and "configured link MTU", and limit the latter according to the
former.
In networks where the DHCP-supplied link MTU is inconsistent with the
hardware or driver capabilities (e.g. a network using jumbo frames),
this will result in iPXE advertising a TCP MSS consistent with a size
that can actually be received.
Note that the term "MTU" is typically used to refer to the maximum
length excluding the link-layer headers; we adopt this usage.
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>
[cloud] Add ability to retrieve Google Compute Engine metadata
For some unspecified "security" reason, the Google Compute Engine
metadata server will refuse any requests that do not include the
non-standard HTTP header "Metadata-Flavor: Google".
Attempt to autodetect such requests (by comparing the hostname against
"metadata.google.internal"), and add the "Metadata-Flavor: Google"
header if applicable.
Enable this feature in the CONFIG=cloud build, and include a sample
embedded script allowing iPXE to boot from a script configured as
metadata via e.g.
# Create shared boot image
make bin/ipxe.usb CONFIG=cloud EMBED=config/cloud/gce.ipxe
# Configure per-instance boot script
gcloud compute instances add-metadata <instance> \
--metadata-from-file ipxeboot=boot.ipxe
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv4] Accept unicast packets for the local network broadcast address
The ISC Kea DHCP server transmits its DHCPOFFER as a unicast packet
with a broadcast IPv4 destination address (255.255.255.255). This
combination is currently rejected by iPXE.
Fix by explicitly accepting the local network broadcast address
(255.255.255.255) as a valid unicast destination address.
Reported-by: Roy Ledochowski <roy.ledochowski@hpe.com>
Tested-by: Roy Ledochowski <roy.ledochowski@hpe.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[iscsi] Avoid potential infinite loops during shutdown
The command and data interfaces may be connected to the same object.
Nullify the data interface before shutting down the control interface
to avoid potential infinite loops.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Select the IPv6 source address and corresponding router (if any) using
a very simplified version of the algorithm from RFC6724:
- Ignore any source address that has a smaller scope than the
destination address. For example, do not use a link-local source
address when sending to a global destination address.
- If we have a source address which is on the same link as the
destination address, then use that source address.
- If we are left with multiple possible source addresses, then choose
the address with the smallest scope. For example, if we are sending
to a site-local destination address and we have both a global source
address and a site-local source address, then use the site-local
source address.
- If we are still left with multiple possible source addresses, then
choose the address with the longest matching prefix.
For the purposes of this algorithm, we treat RFC4193 Unique Local
Addresses as having organisation-local scope. Since we use only
link-local scope for our multicast transmissions, this approximation
should remain valid in all practical situations.
Originally-implemented-by: Thomas Bächler <thomas@archlinux.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv6] Create routing table based on IPv6 settings
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>
[ipv6] Match user expectations for IPv6 settings priorities
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>
[dhcpv6] Expose IPv6 address setting acquired through DHCPv6
Originally-implemented-by: Hannes Reinecke <hare@suse.de>
Originally-implemented-by: Marin Hannache <git@mareo.fr>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expose the IPv6 address (or prefix) as ${ip6}, the prefix length as
${len6}, and the router address as ${gateway6}.
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>
[ipv6] Perform SLAAC only during autoconfiguration
We currently perform IPv6 stateless address autoconfiguration (SLAAC)
in response to any router advertisement with the relevant flags set.
This can result in the local IPv6 source address changing midway
through a TCP connection, since our connections bind only to a local
port number and do not store a local network address.
In addition, this behaviour for SLAAC is inconsistent with that for
DHCPv4 and stateful DHCPv6, both of which will be performed only as a
result of an explicit autoconfiguration action (e.g. via the default
autoboot sequence, or the "ifconf" command).
Fix by ignoring router advertisements arriving outside the context of
an ongoing autoconfiguration attempt.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv4] Send gratuitous ARPs whenever a new IPv4 address is applied
In a busy network (such as a public cloud), IPv4 addresses may be
recycled rapidly. When this happens, unidirectional traffic (such as
UDP syslog) will succeed, but bidirectional traffic (such as TCP
connections) may fail due to stale ARP cache entries on other nodes.
The remote ARP cache expiry timeout is likely to exceed iPXE's
connection timeout, meaning that boot attempts can fail before the
problem is automatically resolved.
Fix by sending gratuitous ARPs whenever an IPv4 address is changed, to
attempt to update stale remote ARP cache entries. Note that this is
not a guaranteed fix, since ARP is an unreliable protocol.
We avoid sending gratuitous ARPs unconditionally, since otherwise any
unrelated settings change (e.g. "set dns 192.168.0.1") would cause
unexpected gratuitous ARPs to be sent.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcp] Automatically generate vendor class identifier string
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>
[dhcpv6] Include vendor class identifier option in DHCPv6 requests
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>
[dhcpv6] Include RFC5970 client architecture options in DHCPv6 requests
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>
[dhcp] Allow for variable encapsulation of architecture-specific options
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>
[tcp] Send TCP keepalives on idle established connections
In some circumstances, intermediate devices may lose state in a way
that temporarily prevents the successful delivery of packets from a
TCP peer. For example, a firewall may drop a NAT forwarding table
entry.
Since iPXE spends most of its time downloading files (and hence purely
receiving data, sending only TCP ACKs), this can easily happen in a
situation in which there is no reason for iPXE's TCP stack to generate
any retransmissions. The temporary loss of connectivity can therefore
effectively become permanent.
Work around this problem by sending TCP keepalives after a period of
inactivity on an established connection.
TCP keepalives usually send a single garbage byte in sequence number
space that has already been ACKed by the peer. Since we do not need
to elicit a response from the peer, we instead send pure ACKs (with no
garbage data) in order to keep the transmit code path simple.
Originally-implemented-by: Ladi Prosek <lprosek@redhat.com>
Debugged-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some HTTP/2 servers send the header "Connection: upgrade, close". This
currently causes iPXE to fail due to the unrecognised "upgrade" token.
Fix by ignoring any unrecognised tokens in the "Connection" header.
Reported-by: Ján ONDREJ (SAL) <ondrejj@salstar.sk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ethernet] Make LACP support configurable at build time
Add a build configuration option NET_PROTO_LACP to control whether or
not LACP support is included for Ethernet devices.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
It is possible for the preloaded UNDI device to end up with no
specified bus type, since it may not be recognised as either a PCI or
an ISAPnP device. This will result in a bus type value of zero, which
currently results in NULL being treated as a string pointer by
netdev_fetch_bustype().
Fix by returning ENOENT if an unknown bus type is specified.
Reported-by: Todd Stansell <todd@stansell.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[crypto] Allow cross-certificate source to be configured at build time
Provide a build option CROSSCERT in config/crypto.h to allow the
default cross-signed certificate source to be configured at build
time. The ${crosscert} setting may still be used to reconfigure the
cross-signed certificate source at runtime.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
There is no practical way to generate an underlength ARP packet since
an ARP packet is always padded up to the minimum Ethernet frame length
(or dropped by the receiving Ethernet hardware if incorrectly padded),
but the absence of an explicit check causes warnings from some
analysis tools.
Fix by adding an explicit check on the I/O buffer length.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tls] Avoid potential out-of-bound reads in length fields
Many TLS records contain variable-length fields. We currently
validate the overall record length, but do so only after reading the
length of the variable-length field. If the record is too short to
even contain the length field, then we may read uninitialised data
from beyond the end of the record.
This is harmless in practice (since the subsequent overall record
length check would fail regardless of the value read from the
uninitialised length field), but causes warnings from some analysis
tools.
Fix by validating that the overall record length is sufficient to
contain the length field before reading from the length field.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[infiniband] Make IPoIB support configurable at build time
Add a build configuration option VNIC_IPOIB to control whether or not
IPoIB support is included for Infiniband devices.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown