[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>
[cmdline] Rename "console" command's --bpp option to --depth
Rename the "--bpp" option to "--depth", to free up the single-letter
option "-b" for "--bottom" in preparation for adding margin support.
This does not break backwards compatibility with documented features,
since the "console" command has not yet been documented.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[vesafb] Allow for an arbitrary margin around the text area
Allow for an arbitrary margin to be specified in the console
configuration. If the actual screen size does not match the requested
screen size, then update any margins specified so that they remain in
the same place relative to the requested screen size. If margins are
unspecified (i.e. zero), then leave them as zero.
The underlying assumption here is that any specified margins are
likely to describe an area within a background picture, and so should
remain in the same place relative to that background picture.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Centre the background picture on the console, to give a more
consistent result when the aspect ratio does not match the requested
width and height.
Once drawn for the first time, nothing should ever overwrite the
margins of the display. We can therefore eliminate the logic used to
redraw only the margin areas, and use much simpler code to draw the
complete initial background image.
Simplify the redrawing logic further by making the background picture
buffer equal in size to the frame buffer. In the common case of a
background picture which is designed to fill the screen, this wastes
no extra memory, and the combined code simplifications reduce the size
of fbcon.o by approximately 15%.
Redefine the concept of "margin" to match the intuitive definition
(i.e. the size of the gap, rather than the position of the boundary
line).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fix incorrect calculation used to determine length of data to be
copied within a literal data block, and add a test case to prevent
this bug from going undetected in future.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[test] Add okx() macro taking an explicit file name and line number
Allow test reports to specify an explicit file name and line number
using the extended okx() macro. This allows large blocks of test
report code such as tcpip_random_ok() to be implemented as functions
rather than macros.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[vesafb] Set "magic" colour to transparent when a background picture is used
Use the magic colour facility to cause the user interface background
to become transparent when we have a background picture.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The magic basic colour can be remapped at runtime from COLOR_NORMAL_BG
(usually blue) to COLOR_DEFAULT (which will be transparent as a
background colour on the framebuffer console).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[console] Add centralised concept of colours and colour pairs
Add a centralised concept of colours and colour pairs (using the
default colour pairs as configured via config/colour.h). A colour
pair consists of a pair of colour indices.
Add the ability to redefine both a colour pair and an individual
colour index, with minimal overhead if this feature is not required
(e.g. because the relevant shell commands are not present in the
build).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[console] Allow consoles to update the recorded console size
Provide a mechanism for consoles to update the recorded console width
and height, and use this width and height to provide the curses COLS
and LINES variables.
We choose not to use ANSI escape sequences to obtain the width and
height, for two reasons:
- iPXE's model is that all output is sent to all consoles; we could
therefore end up with multiple consoles reporting conflicting widths
and heights
- when a serial console is in use, we probably don't want to resize
the output shown on the BIOS console to match the size of the serial
console, since it's likely that the serial console is in use only
for debugging.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[vesafb] Work around data corruption bug in bochs/qemu VBE implementation
The vgabios used by bochs and qemu (and other virtualisation products)
has a bug in its implementation of INT 10,4f00 which causes the high
16 bits of %ebx and %edx to become corrupted.
The vgabios code uses a "pushaw"/"popaw" pair to preserve the low 16
bits of all non-segment registers. The vgabios code is compiled using
bcc, which generates 8086-compatible code and so never touches the
high 16 bits of the 32-bit registers. However, the function
vbe_biosfn_return_controller_information() includes the line:
size_64k = (Bit16u)((Bit32u)cur_info->info.XResolution *
cur_info->info.XResolution *
cur_info->info.BitsPerPixel) >> 19;
which generates an implicit call to the "lmulul" function. This
function is implemented in vbe.c as:
; helper function for memory size calculation
lmulul:
and eax, #0x0000FFFF
shl ebx, #16
or eax, ebx
SEG SS
mul eax, dword ptr [di]
mov ebx, eax
shr ebx, #16
ret
which modifies %eax, %ebx, and %edx (as a result of the "mul"
instruction, which places its result into %edx:%eax).
Work around this problem by marking %ebx and %edx as being clobbered
by the call to INT 10,4f00. (%eax is already used as an output
register, so does not need to be on the clobber list.)
Reported-by: Oliver Rath <rath@mglug.de>
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>
[settings] Allow for multiple definitions of each predefined setting
Allow for multiple setting definitions with the same name but
different scopes and tags. For example, allow for a "filename"
setting with default scope and tag value 67 (for DHCPv4) and a
corresponding "filename" setting with IPv6 scope and tag value 59 (for
DHCPv6).
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>
Michael Brown