[libc] Fix strcmp()/strncmp() to return proper values
Fix strcmp() and strncmp() to return proper standard positive/negative
values for unequal strings. Current implementation is backwards
(i.e. the functions are returning negative when should be positive and
vice-versa).
Currently all consumers of these functions only check the return value
for ==0 or !=0 and so we can safely change the implementation without
breaking things.
Signed-off-by: Aaron Young <Aaron.Young@oracle.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add PEM-encoded ASN.1 as an image format. We accept as PEM any image
containing a line starting with a "-----BEGIN" boundary marker.
We allow for PEM files containing multiple ASN.1 objects, such as a
certificate chain produced by concatenating individual certificate
files.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add DER-encoded ASN.1 as an image format. There is no fixed signature
for DER files. We treat an image as DER if it comprises a single
valid SEQUENCE object covering the entire length of the image.
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>
[pci] Support systems with multiple PCI root bridges
Extend the 16-bit PCI bus:dev.fn address to a 32-bit seg:bus:dev.fn
address, assuming a segment value of zero in contexts where multiple
segments are unsupported by the underlying data structures (e.g. in
the iBFT or BOFM tables).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[libc] Print "<NULL>" for wide-character NULL strings
The existing code intends to print NULL strings as "<NULL>" (for the
sake of debug messages), but the logic is incorrect when handling
wide-character strings. Fix the logic and add applicable unit tests.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[iobuf] Improve robustness of I/O buffer allocation
Guard against various corner cases (such as zero-length buffers, zero
alignments, and integer overflow when rounding up allocation lengths
and alignments) and ensure that the struct io_buffer is correctly
aligned even when the caller requests a non-zero alignment for the I/O
buffer itself.
Add self-tests to verify that the resulting alignments and lengths are
correct for a range of allocations.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The various early-exit paths in parse_uri() accidentally bypass the
URI field decoding. The result is that opaque or relative URIs do not
undergo URI field decoding, resulting in double-encoding when the URIs
are subsequently used. For example:
#!ipxe
set mac ${macstring}
imgfetch /boot/by-mac/${mac:uristring}
would result in an HTTP GET such as
GET /boot/by-mac/00%253A0c%253A29%253Ac5%253A39%253Aa1 HTTP/1.1
rather than the expected
GET /boot/by-mac/00%3A0c%3A29%3Ac5%3A39%3Aa1 HTTP/1.1
Fix by ensuring that URI decoding is always applied regardless of the
URI format.
Reported-by: Andrew Widdersheim <awiddersheim@inetu.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
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>
[tcpip] Avoid generating positive zero for transmitted UDP checksums
TCP/IP checksum fields are one's complement values and therefore have
two possible representations of zero: positive zero (0x0000) and
negative zero (0xffff).
In RFC768, UDP over IPv4 exploits this redundancy to repurpose the
positive representation of zero (0x0000) to mean "no checksum
calculated"; checksums are optional for UDP over IPv4.
In RFC2460, checksums are made mandatory for UDP over IPv4. The
wording of the RFC is such that the UDP header is mandated to use only
the negative representation of zero (0xffff), rather than simply
requiring the checksum to be correct but allowing for either
representation of zero to be used.
In RFC1071, an example algorithm is given for calculating the TCP/IP
checksum. This algorithm happens to produce only the positive
representation of zero (0x0000); this is an artifact of the way that
unsigned arithmetic is used to calculate a signed one's complement
sum (and its final negation).
A common misconception has developed (exemplified in RFC1624) that
this artifact is part of the specification. Many people have assumed
that the checksum field should never contain the negative
representation of zero (0xffff).
A sensible receiver will calculate the checksum over the whole packet
and verify that the result is zero (in whichever representation of
zero happens to be generated by the receiver's algorithm). Such a
receiver will not care which representation of zero happens to be used
in the checksum field.
However, there are receivers in existence which will verify the
received checksum the hard way: by calculating the checksum over the
remainder of the packet and comparing the result against the checksum
field. If the representation of zero used by the receiver's algorithm
does not match the representation of zero used by the transmitter (and
so placed in the checksum field), and if the receiver does not
explicitly allow for both representations to compare as equal, then
the receiver may reject packets with a valid checksum.
For UDP, the combined RFCs effectively mandate that we should generate
only the negative representation of zero in the checksum field.
For IP, TCP and ICMP, the RFCs do not mandate which representation of
zero should be used, but the misconceptions which have grown up around
RFC1071 and RFC1624 suggest that it would be least surprising to
generate only the positive representation of zero in the checksum
field.
Fix by ensuring that all of our checksum algorithms generate only the
positive representation of zero, and explicitly inverting this in the
case of transmitted UDP packets.
Reported-by: Wissam Shoukair <wissams@mellanox.com>
Tested-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Merge the functionality of parse_next_server_and_filename() and
tftp_uri() into a single pxe_uri(), which takes a server address
(IPv4/IPv6/none) and a filename, and produces a URI using the rule:
- if the filename is a hierarchical absolute URI (i.e. includes a
scheme such as "http://" or "tftp://") then use that URI and ignore
the server address,
- otherwise, if the server address is recognised (according to
sa_family) then construct a TFTP URI based on the server address,
port, and filename
- otherwise fail.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit 09b057c ("[settings] Remove "uristring" setting type") removed
support for URI-encoded settings via the "uristring" setting type, on
the basis that such encoding was no longer necessary to avoid problems
with the command line parser.
Other valid use cases for the "uristring" setting type do exist: for
example, a password containing a '/' character expanded via
chain http://username:${password:uristring}@server.name/boot.php
Restore the existence of the "uristring" setting, avoiding the
potentially large stack allocations that were used in the old code
prior to commit 09b057c ("[settings] Remove "uristring" setting
type").
Requested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[image] Detect image type when image is first registered
The current usage pattern of image_probe() is a legacy from the time
before commit 34b6ecb ("[image] Simplify image management") when
loading an image to its executable location in memory was a separate
action from actually executing the image.
Call image_probe() as soon as an image is registered. This allows
"imgstat" to display image type information for all images and allows
image-consuming code to assume that image->type is already set
correctly.
Ignore failures if image_probe() does not recognise the image, since
we do expect to handle unrecognised images (initrds, modules, etc).
Unrecognised images will be left with a NULL image->type, which
image-consuming code can easily check.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow line buffer to accumulate multiple lines, with buffered_line()
returning each freshly-completed line as it is encountered. This
allows buffered lines to be subsequently processed as a group.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv4] Redefine IP address constants to avoid unnecessary byte swapping
Redefine various IPv4 address constants and testing macros to avoid
unnecessary byte swapping at runtime, and slightly rename the macros
to prevent code from accidentally using the old definitions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Generalise the existing support for performing CBC-mode block cipher
tests, and update the code to use okx() for neater reporting of test
results.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[base16] Add buffer size parameter to base16_encode() and base16_decode()
The current API for Base16 (and Base64) encoding requires the caller
to always provide sufficient buffer space. This prevents the use of
the generic encoding/decoding functionality in some situations, such
as in formatting the hex setting types.
Implement a generic hex_encode() (based on the existing
format_hex_setting()), implement base16_encode() and base16_decode()
in terms of the more generic hex_encode() and hex_decode(), and update
all callers to provide the additional buffer length parameter.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[test] Include IPv6 support when performing settings self-tests
The settings self-tests include tests for the "ipv6" setting type.
When IPv6 support is not included, this setting type exists (since it
is referred to by some dual-stack code, such as dns.c) but is
non-functional.
Force IPv6 support to be included within a settings self-test build
using an explicit REQUIRE_OBJECT() macro.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-512/224 is almost identical to SHA-512, with differing initial
hash values and a truncated output length.
This implementation has been verified using the NIST SHA-512/224 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-512/256 is almost identical to SHA-512, with differing initial
hash values and a truncated output length.
This implementation has been verified using the NIST SHA-512/256 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-384 is almost identical to SHA-512, with differing initial hash
values and a truncated output length.
This implementation has been verified using the NIST SHA-384 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-224 is almost identical to SHA-256, with differing initial hash
values and a truncated output length.
This implementation has been verified using the NIST SHA-224 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Update the digest self-tests to use okx(), and centralise concepts and
data shared between tests for multiple algorithms to reduce duplicated
code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At some point in the past few years, binutils became more aggressive
at removing unused symbols. To function as a symbol requirement, a
relocation record must now be in a section marked with @progbits and
must not be in a section which gets discarded during the link (either
via --gc-sections or via /DISCARD/).
Update REQUIRE_SYMBOL() to generate relocation records meeting these
criteria. To minimise the impact upon the final binary size, we use
existing symbols (specified via the REQUIRING_SYMBOL() macro) as the
relocation targets where possible. We use R_386_NONE or R_X86_64_NONE
relocation types to prevent any actual unwanted relocation taking
place. Where no suitable symbol exists for REQUIRING_SYMBOL() (such
as in config.c), the macro PROVIDE_REQUIRING_SYMBOL() can be used to
generate a one-byte-long symbol to act as the relocation target.
If there are versions of binutils for which this approach fails, then
the fallback will probably involve killing off REQUEST_SYMBOL(),
redefining REQUIRE_SYMBOL() to use the current definition of
REQUEST_SYMBOL(), and postprocessing the linked ELF file with
something along the lines of "nm -u | wc -l" to check that there are
no undefined symbols remaining.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The implementation of strtoul() has a partially unknown provenance.
Rewrite this code to avoid potential licensing uncertainty.
Since we now use -ffunction-sections, there is no need to place
strtoull() in a separate file from strtoul().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Aaron Young