iPXE currently advertises a fixed MSS of 1460, which is correct only
for IPv4 over Ethernet. For IPv6 over Ethernet, the value should be
1440 (allowing for the larger IPv6 header). For non-Ethernet link
layers, the value should reflect the MTU of the underlying network
device.
Use tcpip_mtu() to calculate the transport-layer MTU associated with
the peer address, and calculate the MSS to allow for an optionless TCP
header as per RFC 6691.
As a side benefit, we can now fail a connection immediately with a
meaningful error message if we have no route to the destination
address.
Reported-by: Anton D. Kachalov <mouse@yandex-team.ru>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcpip] Provide tcpip_mtu() to determine the maximum transmission unit
Provide the function tcpip_mtu() to allow external code to determine
the (transport-layer) maximum transmission unit for a given socket
address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcpip] Provide tcpip_netdev() to determine the transmitting network device
Provide the function tcpip_netdev() to allow external code to
determine the transmitting network device for a given socket address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add support for parsing of URIs containing literal IPv6 addresses
(e.g. "http://[fe80::69ff:fe50:5845%25net0]/boot.ipxe").
Duplicate URIs by directly copying the relevant fields, rather than by
formatting and reparsing a URI string. This relaxes the requirements
on the URI formatting code and allows it to focus on generating
human-readable URIs (e.g. by not escaping ':' characters within
literal IPv6 addresses). As a side-effect, this allows relative URIs
containing parameter lists (e.g. "../boot.php##params") to function
as expected.
Add validity check for FTP paths to ensure that only printable
characters are accepted (since FTP is a human-readable line-based
protocol with no support for character escaping).
Construct TFTP next-server+filename URIs directly, rather than parsing
a constructed "tftp://..." string,
Add self-tests for URI functions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcp] Copy exactly the required length when resizing DHCP options
When resizing DHCP options, iPXE currently calculates the length to be
copied by subtracting the destination pointer from the end of buffer
pointer. This works and guarantees not to write beyond the end of the
buffer, but may end up reading beyond the end of the buffer.
Fix by calculating the required length exactly.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dns] Update end-of-name pointer after processing CNAME record
Commit d4c0226 ("[dns] Support DNS search lists") introduced a
regression when handling CNAME records resolving to names longer than
the original name. The "end of name" offset stored in dns->offset was
not updated to reflect the length of the new name, causing
dns_question() to append the (empty) search suffix at an incorrect
offset within the name buffer, resulting in a mangled DNS name.
In the case of a CNAME record resolving to a name shorter than or
equal in length to the original name, then the mangling would occur in
an unused portion of the name buffer. In the common case of a name
server returning the A (or AAAA) record along with the CNAME record,
this would cause name resolution to succeed despite the mangling. (If
the name server did not return the A or AAAA record along with the
CNAME record, then the mangling would be revealed by the subsequent
invalid query packet.)
Reported-by: Nicolas Sylvain <nsylvain@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Update the DNS resolver to support DNS search lists (as provided by
DHCP option 119, DHCPv6 option 24, or NDP option 31).
Add validation code to ensure that parsing of DNS packets does not
overrun the input, get stuck in infinite loops, or (worse) write
beyond the end of allocated buffers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow for equivalent IPv4 and IPv6 settings (which requires equivalent
settings to be adjacent within the settings list).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Note that IANA has not yet assigned a DHCPv6 option code for the
syslog server. When a code is assigned, the definition of
DHCPV6_LOG_SERVERS should be updated. Until then, an IPv6 address of
a syslog server can be configured manually using e.g.
set syslog6 3ffe:302:11:2::8309
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dns] Add support for resolving IPv6 addresses via AAAA records
Our policy is to prefer IPv6 addreses to IPv4 addresses, but to
request IPv6 addresses only if we have an IPv6 address for the name
server itself.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Allow for IPv6 setting types in non-IPv6 builds
Allow for the existence of references to IPv6 setting types without
dragging in the whole IPv6 stack, by placing the definition of
setting_type_ipv6 in core/settings.c and providing weak stub methods
for parse_ipv6_setting() and format_ipv6_setting().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Explicitly separate the concept of a completed fetched setting
The fetch_setting() family of functions may currently modify the
definition of the specified setting (e.g. to add missing type
information). Clean up this interface by requiring callers to provide
an explicit buffer to contain the completed definition of the fetched
setting, if required.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv6] Separate the concepts of prefix and address creation
Allow for IPv6 routing table entries to be created for an on-link
prefix where a local address has not yet been assigned to the network
device.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcpv6] Add basic support for stateful and stateless DHCPv6
Add support for the stateful and stateless variants of the DHCPv6
protocol. The resulting settings block is registered as
"net<x>.dhcpv6", and DHCPv6 options can be obtained using
e.g. "${net0.dhcpv6/23:ipv6}" to obtain the IPv6 DNS server address.
IPv6 addresses obtained via stateful DHCPv6 are not yet applied to the
network device.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Include IPv6 within the generic network device configurator
mechanism. The IPv6 configurator will send a router solicitation and
wait for a router advertisement to be received. (As per RFC4861
section 6.3.7, we do this even if advertisements have been received
prior to sending the router solicitation.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[netdevice] Add generic concept of a network device configurator
iPXE supports multiple mechanisms for network device configuration:
DHCPv4 for IPv4, FIP for FCoE, and SLAAC for IPv6. At present, DHCPv4
requires an explicit action (e.g. a "dhcp" command), FIP is initiated
implicitly upon opening a network device, and SLAAC takes place
whenever a RA happens to be received.
Add a generic concept of a network device configurator, which provides
a common interface to triggering configuration and to reporting the
result of the configuration process.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Most network upper-layer drivers do not implement all three methods
(probe, notify, and remove). Save code by making all methods
optional.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[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>
Michael Brown