This patch fixes all the leftovers from the include cleanup campaign. There
were not that many (~400 entries in ~150 files) but it was definitely worth
doing it as it revealed a few duplicates.
global.h was one of the messiest files, it has accumulated tons of
implicit dependencies and declares many globals that make almost all
other file include it. It managed to silence a dependency loop between
server.h and proxy.h by being well placed to pre-define the required
structs, forcing struct proxy and struct server to be forward-declared
in a significant number of files.
It was split in to, one which is the global struct definition and the
few macros and flags, and the rest containing the functions prototypes.
The UNIX_MAX_PATH definition was moved to compat.h.
And also rename standard.c to tools.c. The original split between
tools.h and standard.h dates from version 1.3-dev and was mostly an
accident. This patch moves the files back to what they were expected
to be, and takes care of not changing anything else. However this
time tools.h was split between functions and types, because it contains
a small number of commonly used macros and structures (e.g. name_desc)
which in turn cause the massive list of includes of tools.h to conflict
with the callers.
They remain the ugliest files of the whole project and definitely need
to be cleaned and split apart. A few types are defined there only for
functions provided there, and some parts are even OS-specific and should
move somewhere else, such as the symbol resolution code.
The various hpack files are self-contained, but hpack-tbl was one of
those showing difficulties when pools were added because that began
to add quite some dependencies. Now when built in standalone mode,
it still uses the bare minimum pool definitions and doesn't require
to know the prototypes anymore when only the structures are needed.
Thus the files were moved verbatim except for hpack-tbl which was
split between types and prototypes.
Fortunately that file wasn't made dependent upon haproxy since it was
integrated, better isolate it before it's too late. Its dependency on
api.h was the result of the change from config.h, which in turn wasn't
correct. It was changed back to stddef.h for size_t and sys/types.h for
ssize_t. The recently added reference to MAX() was changed as it was
placed only to avoid a zero length in the non-free-standing version and
was causing a build warning in the hpack encoder.
As reported in issue #485 the test for !len at the end of the
loop in get_var_int() is useless since it was already done inside
the loop. Actually the code is more readable if we remove the first
one so let's do this instead. The resulting code is exactly the same
since the compiler already optimized the test away.
I found on an (old) AIX 5.1 machine that stdint.h didn't exist while
inttypes.h which is expected to include it does exist and provides the
desired functionalities.
As explained here, stdint being just a subset of inttypes for use in
freestanding environments, it's probably always OK to switch to inttypes
instead:
https://pubs.opengroup.org/onlinepubs/009696799/basedefs/stdint.h.html
Also it's even clearer here in the autoconf doc :
https://www.gnu.org/software/autoconf/manual/autoconf-2.61/html_node/Header-Portability.html
"The C99 standard says that inttypes.h includes stdint.h, so there's
no need to include stdint.h separately in a standard environment.
Some implementations have inttypes.h but not stdint.h (e.g., Solaris
7), but we don't know of any implementation that has stdint.h but not
inttypes.h"
RFC7541#6.3 mandates that an error is reported when a dynamic table size
update announces a size larger than the one configured with settings. This
is tested by h2spec using test "hpack/6.3/1".
This must be backported to 1.9 and possibly 1.8 as well.
Tim Dsterhus found using afl-fuzz that some parts of the HPACK decoder
use incorrect bounds checking which do not catch negative values after
a type cast. The first culprit is hpack_valid_idx() which takes a signed
int and is fed with an unsigned one, but a few others are affected as
well due to being designed to work with an uint16_t as in the table
header, thus not being able to detect the high offset bits, though they
are not exposed if hpack_valid_idx() is fixed.
The impact is that the HPACK decoder can be crashed by an out-of-bounds
read. The only work-around without this patch is to disable H2 in the
configuration.
CVE-2018-14645 was assigned to this bug.
This patch addresses all of these issues at once. It must be backported
to 1.8.
Now all the code used to manipulate chunks uses a struct buffer instead.
The functions are still called "chunk*", and some of them will progressively
move to the generic buffer handling code as they are cleaned up.
Chunks are only a subset of a buffer (a non-wrapping version with no head
offset). Despite this we still carry a lot of duplicated code between
buffers and chunks. Replacing chunks with buffers would significantly
reduce the maintenance efforts. This first patch renames the chunk's
fields to match the name and types used by struct buffers, with the goal
of isolating the code changes from the declaration changes.
Most of the changes were made with spatch using this coccinelle script :
@rule_d1@
typedef chunk;
struct chunk chunk;
@@
- chunk.str
+ chunk.area
@rule_d2@
typedef chunk;
struct chunk chunk;
@@
- chunk.len
+ chunk.data
@rule_i1@
typedef chunk;
struct chunk *chunk;
@@
- chunk->str
+ chunk->area
@rule_i2@
typedef chunk;
struct chunk *chunk;
@@
- chunk->len
+ chunk->data
Some minor updates to 3 http functions had to be performed to take size_t
ints instead of ints in order to match the unsigned length here.
Maximilian Bhm and Lucas Rolff both reported some random failed requests
with HTTP/2. Upon deep investigation on detailed traces provided by Lucas,
it turned out that some header names were occasionally corrupted and used
to point to random strings within the dynamic headers table.
The HPACK decoder must always return copies of header names that point
to the dynamic headers table. Otherwise, the insertion of a header after
the current one leading to a reorganization of the table will change the
data the pointer designates. Unfortunately, one such copy was missing for
indexed names, leading to random request failures due to invalid header
names.
Many thanks to Lucas who ran a large number of tests with full traces
helping to capture a reproduceable sequence exhibiting this issue.
This patch must be backported to 1.8.
h2spec reports that we used to support a dynamic table size update
anywhere in the header block but it's only allowed before other
headers (cf RFC7541#4.2.1). In practice we don't use these for now
since we only use literals in responses.
To backport to 1.8.
If the hpack decoder sees an invalid header index, it emits value
"### ERR ###" that was used during debugging instead of rejecting the
block. This is harmless, and was detected by h2spec.
To backport to 1.8.
When a pseudo header is used, name.ptr is NULL and we must replace it
with hpack_idx_to_name(). This only affects code built with DEBUG_HPACK.
To be backported to 1.8.
The current H2 to H1 protocol conversion presents some issues which will
require to perform some processing on certain headers before writing them
so it's not possible to convert HPACK to H1 on the fly.
This commit modifies the headers decoding so that it now works in two
phases : hpack_decode_headers() only decodes the HPACK stream in the
HEADERS frame and puts the result into a list. Headers which require
storage (huffman-compressed or from the dynamic table) are stored in
a chunk allocated by the H2 demuxer. Then once the headers are properly
decoded into this list, h2_make_h1_request() is called with this list
to produce the HTTP/1.1 request into the destination buffer. The list
necessarily enforces a limit. Here we use 2*MAX_HTTP_HDR, which means
that we can have as many individual cookies as we have regular headers
if a client decides to break their cookies into multiple values. This
seams reasonable and will allow the H1 parser to decide whether it's
too much or not.
Thus the output stream is not produced on the fly anymore and this will
permit to deal with certain corner cases like reparing the Cookie header
(which for now is not done).
In order to limit header duplication and parsing, the known pseudo headers
continue to be passed by their index : the name element in the list then
has a NULL pointer and the value is the pseudo header's index. Given that
these ones represent about half of the incoming requests and need to be
found quickly, it maintains an acceptable level of performance.
The code was significantly reduced by doing this because the orignal code
had to deal with HPACK and H1 combinations (eg: index vs not indexed, etc)
and now the HPACK decoding is totally focused on the decompression, and
the H1 encoding doesn't have to deal with the issue of wrapping input for
example.
One bug was addressed here (though it couldn't happen at the moment). The
H2 demuxer used to detect a failure to write the request into the H1 buffer
and would then detect if the output buffer wraps, realign it and try again.
The problem by doing so was that the HPACK context was already modified and
not rewindable. Thus the size check is now performed first and a failure is
reported if it doesn't fit.
The decoder is now fully functional. It makes use of the dynamic header
table. Dynamic header table size updates are currently ignored, as our
initially advertised value is the highest we support. Strictly speaking,
the impact is that a client referencing a header field after such an
update wouldn't observe an error instead of the connection being dropped
if it was implemented.
Decoded header fields are copied into a target buffer in HTTP/1 format
using HTTP/1.1 as the version. The Host header field is automatically
appended if a ":authority" header field is present.
All decoded header fields can be displayed if the file is compiled with
DEBUG_HPACK.
