The exceptions are currently:
Some EXTRACT_ in print-juniper.c, not used on packet buffer pointer.
An EXTRACT_BE_U_3 in addrtoname.c, not always used on packet buffer
pointer.
Structures that describe packet formats now all use nd_ types, none of
which require more than 1-byte alignment, so compilers shouldn't assume
that anything in those structures is aligned on any particular boundary,
even without a "this is unaligned" hint.
Instead, use compiler test macros to check whether *particular*
attributes are supported, and set various #defines appropriately, in
header files.
Rename the UNALIGNED structure attribute to ND_UNALIGNED, and ask
whether we still need it.
IPv6 routing header type 4 is known as Segment Routing Header (SRH).
It is used by Segment Routing (SR) to steer a packet through a
controlled set of instructions, called segments. It is described in
https://tools.ietf.org/html/draft-ietf-6man-segment-routing-header-07
An extension is added to allow tcpdump to print SRH information.
Fix the 'Bus Error - core dumped' issue with the 'ipv6-routing-header' test
when '-m64' compiling option is used.
Fix with the method described in commit 1376682.
/opt/solarisstudio12.3/bin/cc -V
gives:
cc: Sun C 5.12 SunOS_sparc Patch 148917-09 2016/08/02
In RFC 1883, the Type 0 routing header had a 1-byte reserved field and a
3-byte strict/loose bit map; in RFC 2460, that changed to a 4-byte
reserved field.
This fixes a buffer over-read discovered by Brian 'geeknik' Carpenter (by
making an ND_TCHECK() call check for the presence in the captured data
of all 4 bytes of the reserved field; we were printing it as a 4-byte
field, so we needed to check for them).
Add a test using the capture file supplied by the reporter(s).
If we have a routing header, instead of overwriting the packet's IPv6
destination address in the packet with the final destination, so that
the next protocol's checksum routine can use it, we do as we do for
IPv4, and, in the "next protocol checksum" routine, scan the headers
looking for a routing header and, if we find one, copy the final
destination from it.
While we're at it, clean up a few things.
Brian Haley points that mobility (sub-)options decoded in
print-ip6opts.c are specific to draft-ietf-mobileip-ipv6 only. RFC3775
(and respectively RFC6275) uses different encoding and parameter space,
which print-mobility.c already handles.
Remove deprecated code and update some related macros.
Remove lots of $Header's and a few $Id's that all belong to the former
CVS repository of tcpdump itself. These keywords have been frozen since
the migration to git in late 2008.
The Wireshark routine is based on the BSD in-kernel portable checksum
routine (thus BSD-licensed); it takes a vector of pointers and lengths
and checksums the concatenation of the buffers in question (just as the
BSD in-kernel routine checksums a chain of mbufs).
This simplifies the "with a pseudo-header" checksums; hopefully it'll
fix up the problems being seen on some big-endian platforms, which might
be due to hand-calculating some or all of the checksum and doing so
incorrectly. It also gets rid of some code that might be dereferencing
unaligned pointers.
This prevents GCC on SPARC from generating code that assumes those
structures are aligned naturally, which they are not guaranteed to be.
Move some #defines from interface.h to tcpdump-stdinc.h to make them
available to code that doesn't include interface.h.
Move the declaration of nextproto6_cksum() to ip6.h, so that only files
that use it get it declared, and thus so that you don't need to define
"struct ip6_hdr" in everything that includes interface.h. Don't include
ip6.h in tcpdump-stdinc.h.
compile with Sun C, as "interface.h" isn't being included before the
structures are being declared.
Furthermore, in the files that Sun C *can* compile, it doesn't cause Sun
C to generate code that's safe with unaligned accesses, as
"__attribute__" is defined as a do-nothing macro with compilers that
don't support it.
Therefore, we get rid of that tag on the structures to which it was
added, and instead use "EXTRACT_16BIT()" and "EXTRACT_32BIT()" to fetch
16-bit and 32-bit big-endian quantities from packets. We also fix some
other references to multi-byte quantities to get rid of code that tries
to do unaligned loads on platforms that don't support them.
We also throw in a hack that makes those macros use
"__attribute__((packed))" on structures containing only one 16-bit or
32-bit integer to get the compiler to generate unaligned-safe code
rather than doing it by hand. (GCC on SPARC produces the same code that
doing it by hand does; I don't know if GCC on any other big-endian
strict-alignment processor generates better code for that case. On
little-endian processors, as "ntohs()" and "ntohl()" might be functions,
that might actually produce worse code.)
Fix some places to use "%u" rather than "%d" to print unsigned
quantities.
ip6.h is almost normal RFC2292 header.
icmp6.h has couple of extensions (not covered by RFC2292),
like MLD, ICMPv6 nodeinfo, and router renumber.
XXX how to synchronize with future kame changes?
