[pxe] Always retrieve cached DHCPACK and apply to relevant network device
When chainloading, always retrieve the cached DHCPACK packet from the
underlying PXE stack, and apply it as the original contents of the
"net<X>.dhcp" settings block. This allows cached DHCP settings to be
used for any chainloaded iPXE binary (not just undionly.kkpxe).
This change eliminates the undocumented "use-cached" setting. Issuing
the "dhcp" command will now always result in a fresh DHCP request.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv6] Automatically choose source for link-local and multicast destinations
When transmitting to a link-local or multicast destination address,
use the network device's link-local address as the source address if
no explicit source address has been specified.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The IPv6 option length field represents the length of the option data
field, not the overall length of the option.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Merge common functionality between IPv4 and IPv6 ICMP echo handling,
and add support for transmitting ICMP echo requests and delivering
ICMP echo replies to a (not yet implemented) ping_rx() function.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace the existing partially-implemented IPv6 stack with a fresh
implementation.
This implementation is not yet complete. The IPv6 transmit and
receive datapaths are functional (including fragment reassembly and
parsing of arbitrary extension headers). NDP neighbour solicitations
and advertisements are supported. ICMPv6 echo is supported.
At present, only link-local addresses may be used, and there is no way
to specify an IPv6 address as part of a URI (either directly or via
a DNS lookup).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[neighbour] Generalise concept of neighbour discovery
Split the protocol-independent portions of arp.c into a separate file
neighbour.c, to allow for sharing of functionality between IPv4+ARP
and IPv6+NDP.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
IPv6 link-local socket addresses require some way to specify a local
network device. We cannot simply use a pointer to the network device,
since a struct sockaddr_in6 may be long-lived and has no way to hold a
reference to the network device.
Using a network device index allows a socket address to cleanly refer
to a network device without worrying about whether or not that device
continues to exist.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Give tap devices a meaningful name, and avoid segmentation faults when
attempting to retrieve ${net0/bustype} by assigning a new bus type for
tap devices.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow HTTP POST requests to be generated when the URI includes a
parameter list. For example:
#!ipxe
params
param mac ${net0/mac}
param uuid ${uuid}
param asset ${asset}
chain http://boot.ipxe.org/demo/boot.php##params
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[udp] Move high-frequency debug messages to DBGLVL_EXTRA
This makes it possible to leave UDP debugging enabled in order to see
interesting UDP events, without flooding the console with at least one
message per packet.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Clarify usage of the term "named setting"
There are currently two conflicting usages of the term "named setting"
within iPXE: one refers to predefined settings (such as show up in the
"config" UI), the other refers to settings identified by a name (such
as "net0.dhcp/ip").
Split these usages into the term "predefined setting" and "named
setting" to avoid ambiguity.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow any iPXE command expecting a network device name to accept
"netX" as a synonym for "most recently opened network device".
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Make "netX" settings block function as a symbolic link
Add a facility for settings blocks to act as symbolic links to other
settings blocks, and reimplement the "netX" virtual settings block
using this facility.
The primary advantage of this approach is that unscoped settings such
as ${mac} and ${filename} will now reflect the settings obtained from
the most recently opened network device: in most cases, this will mean
the settings obtained from the most recent DHCP attempt. This should
improve conformance to the principle of least astonishment.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcp] Do not send RST for unrecognised connections
On large networks with substantial numbers of monitoring agents,
unwanted TCP connection attempts may end up flooding iPXE's ARP cache.
Fix by silently dropping packets received for unrecognised TCP
connections. This should not cause problems, since many firewalls
will also silently drop any such packets.
Reported-by: Jarrod Johnson <jarrod.b.johnson@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Create an explicit concept of "settings scope" and eliminate the magic
values used for numerical setting tags.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[netdevice] Add netdev_tx_defer() to allow drivers to defer transmissions
Devices with small transmit descriptor rings may temporarily run out
of space. Provide netdev_tx_defer() to allow drivers to defer packets
for retransmission as soon as a descriptor becomes available.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[netdevice] Use link-layer address as part of RNG seed
iPXE currently seeds the random number generator using the system
timer tick count. When large numbers of machines are booted
simultaneously, multiple machines may end up choosing the same DHCP
transaction ID (XID) value; this can cause problems.
Fix by using the least significant (and hence most variable) bits of
each network device's link-layer address to perturb the random number
generator. This introduces some per-machine unique data into the
random number generator's seed, and so reduces the chances of DHCP XID
collisions.
This does not affect the ANS X9.82-compatible random bit generator
used by TLS and other cryptography code, which uses an entirely
separate source of entropy.
Originally-implemented-by: Bernhard Kohl <bernhard.kohl@nsn.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcp] Use PXE byte ordering for UUID in DHCP option 97
The PXE spec does not specify a byte ordering for UUIDs, but RFC4578
suggests that it follows the EFI spec, in which the first three fields
are little-endian.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tftp] Allow TFTP block size to be controlled via the PXE TFTP API
The PXE TFTP API allows the caller to request a particular TFTP block
size. Since mid-2008, iPXE has appended a "?blksize=xxx" parameter to
the TFTP URI constructed internally; nothing has ever parsed this
parameter. Nobody seems to have cared that this parameter has been
ignored for almost five years.
Fix by using xfer_window(), which provides a fairly natural way to
convey the block size information from the PXE TFTP API to the TFTP
protocol layer.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[netdevice] Separate VLAN support from presence of VLAN-supporting drivers
Some NICs (e.g. Hermon) provide hardware support for stripping the
VLAN tag, but do not provide any way for this support to be disabled.
Drivers for this hardware must therefore call vlan_find() to identify
a suitable receiving network device.
Provide a weak version of vlan_find() which will always return NULL if
VLAN support has not been enabled (either directly, or by enabling
a feature such as FCoE which requires VLAN support). This allows the
VLAN code to be omitted from builds where the user has not requested
support for VLANs.
Inspired-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown