All files that were including one of the following include files have
been updated to only include haproxy/api.h or haproxy/api-t.h once instead:
- common/config.h
- common/compat.h
- common/compiler.h
- common/defaults.h
- common/initcall.h
- common/tools.h
The choice is simple: if the file only requires type definitions, it includes
api-t.h, otherwise it includes the full api.h.
In addition, in these files, explicit includes for inttypes.h and limits.h
were dropped since these are now covered by api.h and api-t.h.
No other change was performed, given that this patch is large and
affects 201 files. At least one (tools.h) was already freestanding and
didn't get the new one added.
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"
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.
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.
