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>
[tftp] Do not change current working URI when TFTP server is cleared
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>
[dhcp] Limit maximum number of DHCP discovery deferrals
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>
[dhcp] Do not skip ProxyDHCPREQUEST if next-server is empty
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>
[dhcp] Allow pseudo-DHCP servers to use pseudo-identifiers
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>
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
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>
[dhcp] Extract timing parameters out to config/dhcp.h
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>
[tftp] Explicitly abort connection whenever parent interface is closed
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>
[dhcp] Check for matching chaddr in received DHCP packets
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>
[dhcpv6] Do not set sin6_scope_id on the unspecified client socket address
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>
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>
[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>
[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>
[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>
[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>
[ipoib] Expose Ethernet-compatible eIPoIB link-layer addresses and headers
Almost all clients of the raw-packet interfaces (UNDI and SNP) can
handle only Ethernet link layers. Expose an Ethernet-compatible link
layer to local clients, while remaining compatible with IPoIB on the
wire. This requires manipulation of ARP (but not DHCP) packets within
the IPoIB driver.
This is ugly, but it's the only viable way to allow IPoIB devices to
be driven via the raw-packet interfaces.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcp] Request broadcast responses when we already have an IPv4 address
FCoE requires the use of multiple local unicast link-layer addresses.
To avoid the complexity of managing multiple addresses, iPXE operates
in promiscuous mode. As a consequence, any unicast packets with
non-matching IPv4 addresses are rejected at the IPv4 layer (rather
than at the link layer).
This can cause problems when issuing a second DHCP request: if the
address chosen by the DHCP server does not match the existing address,
then the DHCP response will itself be rejected.
Fix by requesting a broadcast response from the DHCP server if the
network interface already has any IPv4 addresses.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow TFTP to be configured out by moving the next-server setting
definition (which is used by autoboot.c) from tftp.c to settings.c.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[syslog] Pass internal syslog() priority through to syslog console
Use a private ANSI escape sequence to convey the priority of an
internal syslog() message through to the syslog server.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[console] Do not share ANSI escape context between lineconsole users
An ANSI escape sequence context cannot be shared between multiple
users. Make the ANSI escape sequence context part of the line console
definition and provide individual contexts for each user.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown