Commit graph

83 commits

Author SHA1 Message Date
Willy Tarreau
b52a0e6782 BUG/MINOR: h2: only accept :protocol with extended CONNECT
As reported by Huangbin Zhan in github issue #3355, we're too lax on
the :protocol pseudo header. It is currently accepted with regular
CONNECT as well as non-CONNECT methods while it only ought to be
accepted with extended CONNECT (i.e. CONNECT after the connection
negotiated the RFC8441 extension). Let's refine the check in H2 by
leveraging the new flag H2_MSGF_EXT_CONN_OK that is passed by the
caller when the connection supports the extension. This is sufficient
to sort the various cases.

The proto upgrade regtest was updated to verify that CONNECT with
:protocol without nego and another method with nego and :protocol
both fail.

Thanks to Huangbin Zhan (@zhanhb) for the report and helpful reproducer.

This needs to be backported to all versions. It relies on these patches
first:

  REGTESTS: http-messaging: always send RFC8441 client settings to use ext connect
  BUG/MINOR: mux-h2: condition the processing of 8441 extension to global setting
  MINOR: mux-h2: add a new message flag to indicate ext connect support
2026-05-05 14:10:36 +02:00
Willy Tarreau
f8385ef165 CLEANUP: tree-wide: fix around 20 mistakes in comments in h2,tools,peers
This cleans up around 12 non-visible typos in h2 and mux-h2, 6 in peers,
3 in tools, and also addresses a leftover after commit 9294e8822f in 2.4
which changed the word fingerprint calculation without updating the
comment about the possible output values. No backport needed.
2026-04-27 14:47:39 +02:00
Christopher Faulet
ba7dc46a92 BUG/MINOR: h2/h3: Never insert partial headers/trailers in an HTX message
In HTX, headers and trailers parts must always be complete. It is unexpected
to found header blocks without the EOH block or trailer blocks without the
EOT block. So, during H2/H3 message parsing, we must take care to remove any
HEADER/TRAILER block inserted when an error is encountered. It is mandatory
to be sure to properly report parsing error to upper layer.x

It is now performed by calling htx_truncat_blk() function on the error
path. The tail block is saved before converting any HEADERS/TRAILERS frame
to HTX. It is used to remove all inserted block on error.

This patch rely on the following one:

  "MINOR: htx: Add function to truncate all blocks after a specific block"

It should be backported with the commit above to all stable versions for
the H2 part and as far as 2.8 for h3 one.
2026-03-17 07:48:02 +01:00
Christopher Faulet
3250ec6e9c BUG/MINOR: h2/h3: Only test number of trailers inserted in HTX message
When H2 or H3 trailers are inserted in an HTX message, we must take care to
not exceed the maximum number of trailers allowed in a message (same than
the maximum number of headers, i.e tune.http.maxhdr). However, all HTX
blocks in the HTX message were considered. Only TRAILERS HTX blocks must be
considered.

To fix the issue, in h2_make_htx_trailers(), we rely on the "idx" variable
at the end of the for loop. In h3_trailers_to_htx(), we rely on the
"hdr_idx" variable.

This patch must be backported to all stables versions for the H2 part and as
far as 2.8 for the H3 one.

pouet
2026-03-17 07:48:02 +01:00
zhanhb
7163d9180c BUG/MINOR: h2: forbid 'Z' as well in header field names checks
The current tests in h2_make_htx_request(), h2_make_htx_response()
and h2_make_htx_trailers() check for an interval between 'A' and 'Z'
for letters in header field names that should be forbidden, but
mistakenly leave the 'Z' out of the forbidden range, resulting in it
being implicitly valid.

This has no real consequences but should be fixed for the sake of
protocol validity checking.

This must be backported to all relevant versions.
2025-10-02 15:29:58 +02:00
Willy Tarreau
df00164fdd BUG/MEDIUM: h1/h2/h3: reject forbidden chars in the Host header field
In continuation with 9a05c1f574 ("BUG/MEDIUM: h2/h3: reject some
forbidden chars in :authority before reassembly") and the discussion
in issue #2941, @DemiMarie rightfully suggested that Host should also
be sanitized, because it is sometimes used in concatenation, such as
this:

    http-request set-url https://%[req.hdr(host)]%[pathq]

which was proposed as a workaround for h2 upstream servers that require
:authority here:

    https://www.mail-archive.com/haproxy@formilux.org/msg43261.html

The current patch then adds the same check for forbidden chars in the
Host header, using the same function as for the patch above, since in
both cases we validate the host:port part of the authority. This way
we won't reconstruct ambiguous URIs by concatenating Host and path.

Just like the patch above, this can be backported afer a period of
observation.
2025-05-16 15:13:17 +02:00
Willy Tarreau
9a05c1f574 BUG/MEDIUM: h2/h3: reject some forbidden chars in :authority before reassembly
As discussed here:
   https://github.com/httpwg/http2-spec/pull/936
   https://github.com/haproxy/haproxy/issues/2941

It's important to take care of some special characters in the :authority
pseudo header before reassembling a complete URI, because after assembly
it's too late (e.g. the '/'). This patch does this, both for h2 and h3.

The impact on H2 was measured in the worst case at 0.3% of the request
rate, while the impact on H3 is around 1%, but H3 was about 1% faster
than H2 before and is now on par.

It may be backported after a period of observation, and in this case it
relies on this previous commit:

   MINOR: http: add a function to validate characters of :authority

Thanks to @DemiMarie for reviving this topic in issue #2941 and bringing
new potential interesting cases.
2025-05-12 18:02:47 +02:00
Ilia Shipitsin
27a6353ceb CLEANUP: assorted typo fixes in the code, commits and doc 2025-04-03 11:37:25 +02:00
Willy Tarreau
bbf824933f BUG/MINOR: h2: always trim leading and trailing LWS in header values
Annika Wickert reported some occasional disconnections between haproxy
and varnish when communicating over HTTP/2, with varnish complaining
about protocol errors while captures looked apparently normal. Nils
Goroll managed to reproduce this on varnish by injecting the capture of
the outgoing haproxy traffic and noticed that haproxy was forwarding a
header value containing a trailing space, which is now explicitly
forbidden since RFC9113.

It turns out that the only way for such a header to pass through haproxy
is to arrive in h2 and not be edited, in which case it will arrive in
HTX with its undesired spaces. Since the code dealing with HTX headers
always trims spaces around them, these are not observable in dumps, but
only when started in debug mode (-d). Conversions to/from h1 also drop
the spaces.

With this patch we trim LWS both on input and on output. This way we
always present clean headers in the whole stack, and even if some are
manually crafted by the configuration or Lua, they will be trimmed on
the output.

This must be backported to all stable versions.

Thanks to Annika for the helpful capture and Nils for the help with
the analysis on the varnish side!
2025-02-24 09:39:57 +01:00
Christopher Faulet
63d2760dfa BUG/MEDIUM: mux-h2: Check the number of headers in HEADERS frame after decoding
There is no explicit test on the number of headers when a HEADERS frame is
received. It is implicitely limited by the size of the header list. But it
is twice the configured limit to be sure to decode the frame.

So now, a check is performed after the HTX message was created. This way, we
are sure to not exceed the configured limit after the decoding stage. If
there are too many headers, a parsing error is reported.

Note the same is performed on the trailers.

This patch should patially address the issue #2685. It should be backported
to all stable versions.
2024-11-20 17:44:22 +01:00
Christopher Faulet
4de6632693 MINOR: proxy: Rename accept-invalid-http-* options
With these options, it is possible to accept some invalid messages that may
considered as unsafe and may result as vulnerabilities. The naming is not
explicit enough on this point. These option must really be considered as
dangerous and only used as a temporary workaround. Unfortunately, when used,
it is probably because there are some legacy and unsupported applications in
place. Nevermind. The documentation warns about the use of these
options. Now the name of the options itself is a warning.

So now, "accept-invalid-http-request" and "accept-invalid-http-response"
options are deprecated and replaced by
"accept-unsafe-violations-in-http-request" and
"accept-unsafe-violations-in-http-response" options.
2024-09-16 22:55:25 +02:00
Christopher Faulet
6743e128f3 BUG/MEDIUM: h2: Only report early HTX EOM for tunneled streams
For regular H2 messages, the HTX EOM flag is synonymous the end of input. So
SE_FL_EOI flag must also be set on the stream-endpoint descriptor. However,
there is an exception. For tunneled streams, the end of message is reported
on the HTX message just after the headers. But in that case, no end of input
is reported on the SE.

But here, there is a bug. The "early" EOM is also report on the HTX messages
when there is no payload (for instance a content-length set to 0). If there
is no ES flag on the H2 HEADERS frame, it is an unexpected case. Because for
the applicative stream and most probably for the opposite endpoint, the
message is considered as finihsed. It is switched in its DONE state (or the
equivalent on the endpoint). But, if an extra H2 frame with the ES flag is
received, a TRAILERS frame or an emtpy DATA frame, an extra EOT HTX block is
pushed to carry the HTX EOM flag. So an extra HTX block is emitted for a
regular HTX message. It is totally invalid, it must never happen.

Because it is an undefined behavior, it is difficult to predict the result.
But it definitly prevent the applicative stream to properly handle aborts
and errors because data remain blocked in the channel buffer. Indeed, the
end of the message was seen, so no more data are forwarded.

It seems to be an issue for 2.8 and upper. Harder to evaluate for older
versions.

This patch must be backported as far as 2.4.
2024-08-02 08:42:28 +02:00
Amaury Denoyelle
7a5a30d28a BUG/MINOR: h2: reject extended connect for h2c protocol
This commit prevents forwarding of an HTTP/2 Extended CONNECT when "h2c"
or "h2" token is set as targetted protocol. Contrary to the previous
commit which deals with HTTP/1 mux, this time the request is rejected
and a RESET_STREAM is reported to the client.

This must be backported up to 2.4 after a period of observation.
2024-08-01 18:23:44 +02:00
Christopher Faulet
eb346074bb MINOR: h2: Set the BODYLESS_RESP flag on the HTX start-line if necessary
When message headers are parsed and an HTX start-line is created, if we
detect the response must not have any payload, a specific flag must be set
on the HTX start-line. It happens for instance for response to HEAD
requests. This flag is useb by the multiplexers to know response payload, if
any, must be silently skipped.

This was not performed when h2 HEADERS frames were decoded. This HTX flag
was specifically added to fix a bug when the splicing is inuse. Thus the H2
multiplexer was not concerned. Because the mux-to-mux fast-forwarding will
be introduced, it is important handle this flag in the H2 multiplexer too.
2023-10-17 18:51:13 +02:00
Willy Tarreau
b3119d4fb4 BUG/MINOR: h2: reject more chars from the :path pseudo header
This is the h2 version of this previous fix:

    BUG/MINOR: h1: do not accept '#' as part of the URI component

In addition to the current NUL/CR/LF, this will also reject all other
control chars, the space and '#' from the :path pseudo-header, to avoid
taking the '#' for a part of the path. It's still possible to fall back
to the previous behavior using "option accept-invalid-http-request".

This patch modifies the request parser to change the ":path" pseudo header
validation function with a new one that rejects 0x00-0x1F (control chars),
space and '#'. This way such chars will be dropped early in the chain, and
the search for '#' doesn't incur a second pass over the header's value.

This should be progressively backported to stable versions, along with the
following commits it relies on:

     REGTESTS: http-rules: add accept-invalid-http-request for normalize-uri tests
     REORG: http: move has_forbidden_char() from h2.c to http.h
     MINOR: ist: add new function ist_find_range() to find a character range
     MINOR: http: add new function http_path_has_forbidden_char()
     MINOR: h2: pass accept-invalid-http-request down the request parser
2023-08-08 19:56:41 +02:00
Willy Tarreau
d93a00861d MINOR: h2: pass accept-invalid-http-request down the request parser
We're adding a new argument "relaxed" to h2_make_htx_request() so that
we can control its level of acceptance of certain invalid requests at
the proxy level with "option accept-invalid-http-request". The goal
will be to add deactivable checks that are still desirable to have by
default. For now no test is subject to it.
2023-08-08 19:10:54 +02:00
Willy Tarreau
d4069f3cee REORG: http: move has_forbidden_char() from h2.c to http.h
This function is not H2 specific but rather generic to HTTP. We'll
need it in H3 soon, so let's move it to HTTP and rename it to
http_header_has_forbidden_char().
2023-08-08 19:02:24 +02:00
Amaury Denoyelle
15f3cc4b38 MINOR: http: extract content-length parsing from H2
Extract function h2_parse_cont_len_header() in the generic HTTP module.
This allows to reuse it for all HTTP/x parsers. The function is now
available as http_parse_cont_len_header().

Most notably, this will be reused in the next bugfix for the H3 parser.
This is necessary to check that content-length header match the length
of DATA frames.

Thus, it must be backported to 2.6.
2022-12-14 11:34:18 +01:00
Willy Tarreau
d8a44d0b24 BUG/MINOR: h2: properly set the direction flag on HTX response
In 1.9-dev, a new flag was introduced on the start line with commit
f1ba18d7b ("MEDIUM: htx: Don't rely on h1_sl anymore except during H1
header parsing") to designate a response message: HTX_SL_F_IS_RESP.

Unfortunately as it was done in parallel to the mux_h2 support for
the backend, it was never integrated there. It was not used by then
so this remained unnoticed for a while.

However the http_client now uses it, and missing that flag prevents
it from using the H2 mux, so let's properly add it.

There's no point in backporting this far away, but since the http_client
is fully operational in 2.6 it would make sense to backport this fix at
least there to secure the code.
2022-09-02 11:19:07 +02:00
Amaury Denoyelle
2c5a7ee333 REORG: h2: extract cookies concat function in http_htx
As specified by RFC 7540, multiple cookie headers are merged in a single
entry before passing it to a HTTP/1.1 connection. This step is
implemented during headers parsing in h2 module.

Extract this code in the generic http_htx module. This will allow to
reuse it quickly for HTTP/3 implementation which has the same
requirement for cookie headers.
2022-08-18 16:13:33 +02:00
Tim Duesterhus
7750850594 CLEANUP: Reapply ist.cocci with --include-headers-for-types --recursive-includes
Previous uses of `ist.cocci` did not add `--include-headers-for-types` and
`--recursive-includes` preventing Coccinelle seeing `struct ist` members of
other structs.

Reapply the patch with proper flags to further clean up the use of the ist API.

The command used was:

    spatch -sp_file dev/coccinelle/ist.cocci -in_place --include-headers --include-headers-for-types --recursive-includes --dir src/
2022-03-21 08:30:47 +01:00
Tim Duesterhus
4c8f75fc31 CLEANUP: Apply ist.cocci
Make use of the new rules to use `istend()`.
2021-11-08 08:05:39 +01:00
Willy Tarreau
46b7dff8f0 BUG/MEDIUM: h2: match absolute-path not path-absolute for :path
RFC7540 states that :path follows RFC3986's path-absolute. However
that was a bug introduced in the spec between draft 04 and draft 05
of the spec, which implicitly causes paths starting with "//" to be
forbidden. HTTP/1 (and now HTTP core semantics) made it explicit
that the request-target in origin-form follows a purposely defined
absolute-path defined as 1*(/ segment) to explicitly allow "//".

http2bis now fixes this by relying on absolute-path so that "//"
becomes valid and matches other versions. Full discussion here:

  https://lists.w3.org/Archives/Public/ietf-http-wg/2021JulSep/0245.html

This issue appeared in haproxy with commit 4b8852c70 ("BUG/MAJOR: h2:
verify that :path starts with a '/' before concatenating it") when
making the checks on :path fully comply with the spec, and was backported
as far as 2.0, so this fix must be backported there as well to allow
"//" in H2 again.
2021-08-19 23:38:18 +02:00
Willy Tarreau
b5d2b9e154 BUG/MEDIUM: h2: give :authority precedence over Host
The wording regarding Host vs :authority in RFC7540 is ambiguous as it
says that an intermediary must produce a host header from :authority if
Host is missing, but, contrary to HTTP/1.1, doesn't say anything regarding
the possibility that Host and :authority differ, which leaves Host with
higher precedence there. In addition it mentions that clients should use
:authority *instead* of Host, and that H1->H2 should use :authority only
if the original request was in authority form. This leaves some gray
area in the middle of the chain for fully valid H2 requests arboring a
Host header that are forwarded to the other side where it's possible to
drop the Host header and use the authority only after forwarding to a
second H2 layer, thus possibly seeing two different values of Host at
a different stage. There's no such issue when forwarding from H2 to H1
as the authority is dropped only only the Host is kept.

Note that the following request is sufficient to re-normalize such a
request:

   http-request set-header host %[req.hdr(host)]

The new spec in progress (draft-ietf-httpbis-http2bis-03) addresses
this trouble by being a bit is stricter on these rules. It clarifies
that :authority must always be used instead of Host and that Host ought
to be ignored. This is much saner as it avoids to convey two distinct
values along the chain. This becomes the protocol-level equivalent of:

   http-request set-uri %[url]

So this patch does exactly this, which we were initially a bit reluctant
to do initially by lack of visibility about other implementations'
expectations. In addition it slightly simplifies the Host header field
creation by always placing it first in the list of headers instead of
last; this could also speed up the look up a little bit.

This needs to be backported to 2.0. Non-HTX versions are safe regarding
this because they drop the URI during the conversion to HTTP/1.1 so
only Host is used and transmitted.

Thanks to Tim Düsterhus for reporting that one.
2021-08-17 10:21:07 +02:00
Willy Tarreau
89265224d3 BUG/MAJOR: h2: enforce stricter syntax checks on the :method pseudo-header
Before HTX was introduced, all the HTTP request elements passed in
pseudo-headers fields were used to build an HTTP/1 request whose syntax
was then scrutinized by the HTTP/1 parser, leaving no room to inject
invalid characters.

While NUL, CR and LF are properly blocked, it is possible to inject
spaces in the method so that once translated to HTTP/1, fields are
shifted by one spcae, and a lenient HTTP/1 server could possibly be
fooled into using a part of the method as the URI. For example, the
following request:

   H2 request
     :method: "GET /admin? HTTP/1.1"
     :path:   "/static/images"

would become:

   GET /admin? HTTP/1.1 /static/images HTTP/1.1

It's important to note that the resulting request is *not* valid, and
that in order for this to be a problem, it requires that this request
is delivered to an already vulnerable HTTP/1 server.

A workaround here is to reject malformed methods by placing this rule
in the frontend or backend, at least before leaving haproxy in H1:

   http-request reject if { method -m reg [^A-Z0-9] }

Alternately H2 may be globally disabled by commenting out the "alpn"
directive on "bind" lines, and by rejecting H2 streams creation by
adding the following statement to the global section:

   tune.h2.max-concurrent-streams 0

This patch adds a check for each character of the method to make sure
they belong to the ones permitted in a token, as mentioned in RFC7231#4.1.

This should be backported to versions 2.0 and above. For older versions
not having HTX_FL_PARSING_ERROR, a "goto fail" works as well as it
results in a protocol error at the stream level. Non-HTX versions are
safe because the resulting invalid request will be rejected by the
internal HTTP/1 parser.

Thanks to Tim Düsterhus for reporting that one.
2021-08-17 10:18:52 +02:00
Willy Tarreau
4b8852c70d BUG/MAJOR: h2: verify that :path starts with a '/' before concatenating it
Tim Düsterhus found that while the H2 path is checked for non-emptiness,
invalid chars and '*', a test is missing to verify that except for '*',
it always starts with exactly one '/'. During the reconstruction of the
full URI when passing to HTX, this missing test allows to affect the
apparent authority by appending a port number or a suffix name.

This only affects H2-to-H2 communications, as H2-to-H1 do not use the
full URI. Like for previous fix, the following rule inserted before
other ones in the frontend is sufficient to renormalize the internal
URI and let haproxy see the same authority as the target server:

    http-request set-uri %[url]

This needs to be backported to 2.2. Earlier versions do not rebuild a
full URI using the authority and will fail on the malformed path at the
HTTP layer, so they are safe.
2021-08-17 10:16:22 +02:00
Willy Tarreau
a495e0d948 BUG/MAJOR: h2: verify early that non-http/https schemes match the valid syntax
While we do explicitly check for strict character sets in the scheme,
this is only done when extracting URL components from an assembled one,
and we have special handling for "http" and "https" schemes directly in
the H2-to-HTX conversion. Sadly, this lets all other ones pass through
if they start exactly with "http://" or "https://", allowing the
reconstructed URI to start with a different looking authority if it was
part of the scheme.

It's interesting to note that in this case the valid authority is in
the Host header and that the request will only be wrong if emitted over
H2 on the backend side, since H1 will not emit an absolute URI by
default and will drop the scheme. So in essence, this is a variant of
the scheme-based attack described below in that it only affects H2-H2
and not H2-H1 forwarding:

   https://portswigger.net/research/http2

As such, a simple workaround consists in just inserting the following
rule before other ones in the frontend, which will have for effect to
renormalize the authority in the request line according to the
concatenated version (making haproxy see the same authority and host
as what the target server will see):

   http-request set-uri %[url]

This patch simply adds the missing syntax checks for non-http/https
schemes before the concatenation in the H2 code. An improvement may
consist in the future in splitting these ones apart in the start
line so that only the "url" sample fetch function requires to access
them together and that all other places continue to access them
separately. This will then allow the core code to perform such checks
itself.

The patch needs to be backported as far as 2.2. Before 2.2 the full
URI was not being reconstructed so the scheme and authority part were
always dropped from H2 requests to leave only origin requests. Note
for backporters: this depends on this previous patch:

  MINOR: http: add a new function http_validate_scheme() to validate a scheme

Many thanks to Tim Düsterhus for figuring that one and providing a
reproducer.
2021-08-17 10:16:22 +02:00
Amaury Denoyelle
4ca0f363a1 MEDIUM: h2: apply scheme-based normalization on h2 requests
Apply the rfc 3986 scheme-based normalization on h2 requests. This
process will be executed for most of requests because scheme and
authority are present on every h2 requests, except CONNECT. However, the
normalization will only be applied on requests with defaults http port
(http/80 or https/443) explicitly specified which most http clients
avoid.

This change is notably useful for http2 websockets with Firefox which
explicitly specify the 443 default port on Extended CONNECT. In this
case, users can be trapped if they are using host routing without
removing the port. With the scheme-based normalization, the default port
will be removed.

To backport this change, it is required to backport first the following
commits:
* MINOR: http: implement http_get_scheme
* MEDIUM: http: implement scheme-based normalization
2021-07-07 15:34:01 +02:00
Christopher Faulet
2b78f0bfc4 CLEANUP: htx: Remove unsued hdrs_bytes field from the HTX start-line
Thanks to the htx_xfer_blks() refactoring, it is now possible to remove
hdrs_bytes field from the start-line because no function rely on it anymore.
2021-04-28 10:51:08 +02:00
Tim Duesterhus
1568355afd CLEANUP: Replace for loop with only a condition by while
Refactoring performed with the following Coccinelle patch:

    @@
    expression e;
    statement S;
    @@

    - for (;e;)
    + while (e)
      S
2021-03-05 08:28:53 +01:00
Ilya Shipitsin
acf84595a7 CLEANUP: assorted typo fixes in the code and comments
This is 17th iteration of typo fixes
2021-02-08 10:49:08 +01:00
Amaury Denoyelle
c9a0afcc32 MEDIUM: h2: parse Extended CONNECT request to htx
Support for the rfc 8441 Bootstraping WebSockets with HTTP/2

Convert an Extended CONNECT HTTP/2 request into a htx representation.
The htx message uses the GET method with an Upgrade header field to be
fully compatible with the equivalent HTTP/1.1 Upgrade mechanism.

The Extended CONNECT is of the following form :

:method = CONNECT
:protocol = websocket
:scheme = https
:path = /chat
:authority = server.example.com

The new pseudo-header :protocol has been defined and is used to identify
an Extended CONNECT method. Contrary to standard CONNECT, Extended
CONNECT must have :scheme, :path and :authority defined.
2021-01-28 16:37:14 +01:00
Amaury Denoyelle
7416274914 MEDIUM: h2: parse Extended CONNECT reponse to htx
Support for the rfc 8441 Bootstraping WebSockets with HTTP/2

Convert a 200 status reply from an Extended CONNECT request into a htx
representation. The htx message is set to 101 status code to be fully
compatible with the equivalent HTTP/1.1 Upgrade mechanism.

This conversion is only done if the stream flags H2_SF_EXT_CONNECT_SENT
has been set. This is true if an Extended CONNECT request has already
been seen on the stream.

Besides the 101 status, the additional headers Connection/Upgrade are
added to the htx message. The protocol is set from the value stored in
h2s. Typically it will be extracted from the client request. This is
only used if the client is using h1 as only the HTTP/1.1 101 Response
contains the Upgrade header.
2021-01-28 16:37:14 +01:00
Christopher Faulet
7d247f0771 MINOR: h2/mux-h2: Add flags to notify the response is known to have no body
The H2 message flag H2_MSGF_BODYLESS_RSP is now used during the request or
the response parsing to notify the mux that, considering the parsed message,
the response is known to have no body. This happens during HEAD requests
parsing and during 204/304 responses parsing.

On the H2 multiplexer, the equivalent flag is set on H2 streams. Thus the
H2_SF_BODYLESS_RESP flag is set on a H2 stream if the H2_MSGF_BODYLESS_RSP
is found after a HEADERS frame parsing. Conversely, this flag is also set
when a HEADERS frame is emitted for HEAD requests and for 204/304 responses.

The H2_SF_BODYLESS_RESP flag will be used to ignore data payload from the
response but not the trailers.
2021-01-28 16:37:14 +01:00
Christopher Faulet
d1ac2b90cd MAJOR: htx: Remove the EOM block type and use HTX_FL_EOM instead
The EOM block may be removed. The HTX_FL_EOM flags is enough. Most of time,
to know if the end of the message is reached, we just need to have an empty
HTX message with HTX_FL_EOM flag set. It may also be detected when the last
block of a message with HTX_FL_EOM flag is manipulated.

Removing EOM blocks simplifies the HTX message filling. Indeed, there is no
more edge problems when the message ends but there is no more space to write
the EOM block. However, some part are more tricky. Especially the
compression filter or the FCGI mux. The compression filter must finish the
compression on the last DATA block. Before it was performed on the EOM
block, an extra DATA block with the checksum was added. Now, we must detect
the last DATA block to be sure to finish the compression. The FCGI mux on
its part must be sure to reserve the space for the empty STDIN record on the
last DATA block while this record was inserted on the EOM block.

The H2 multiplexer is probably the part that benefits the most from this
change. Indeed, it is now fairly easier to known when to set the ES flag.

The HTX documentaion has been updated accordingly.
2021-01-28 16:37:14 +01:00
Christopher Faulet
42432f347f MINOR: htx: Rename HTX_FL_EOI flag into HTX_FL_EOM
The HTX_FL_EOI flag is not well named. For now, it is not very used. But
that will change. It will replace the EOM block. Thus, it is renamed.
2021-01-28 16:37:14 +01:00
Christopher Faulet
5be651d4d7 BUG/MAJOR: mux-h1/mux-h2/htx: Fix HTTP tunnel management at the mux level
Tunnel management between the H1 and H2 multiplexers is a bit blurred. And
the HTX is not enough well defined on this point to make things clear. In
fact, Establishing a tunnel between an H2 client and an H1 server, or the
opposite is buggy because the both multiplexers don't handle the EOM block
the same way when a tunnel is established. In fact, the H2 multiplexer is
pretty strict and add an END_STREAM flag when an EOM block is found, while
the H1 multiplexer is more flexible.

The purpose of this patch is to make the EOM block usage pretty clear and to
fix the HTTP multiplexers to really handle HTTP tunnels in the right
way. Now, an EOM block is used to mark the end of an HTTP message,
semantically speaking. That means it may be followed by tunneled data. Thus,
CONNECT requests are now finished by an EOM block, just after the EOH block.

On the H1 multiplexer side, a tunnel is now only established on the response
path. So a CONNECT request remains in a DONE state waiting for the 2xx
response. On the H2 multiplexer side, a flag is used to know an HTTP tunnel
is requested, to not immediately add the END_STREAM flag on the EOM block.

All these changes are sensitives and not backportable because of recent
changes. The same problem exists on earlier versions and should be
addressed. But it will only be possible with a specific patchset.

This patch relies on the following ones :

  * MEDIUM: mux-h1: Properly handle tunnel establishments and aborts
  * MEDIUM: mux-h2: Close streams when processing data for an aborted tunnel
  * MEDIUM: mux-h2: Block client data on server side waiting tunnel establishment
  * MINOR: mux-h2: Add 2 flags to help to properly handle tunnel mode
  * MINOR: mux-h1: Split H1C_F_WAIT_OPPOSITE flag to separate input/output sides
  * MINOR: mux-h1/mux-fcgi: Don't set TUNNEL mode if payload length is unknown
2021-01-28 16:37:14 +01:00
Christopher Faulet
d0db42326d MINOR: mux-h2: Add 2 flags to help to properly handle tunnel mode
H2_SF_BODY_TUNNEL and H2_SF_TUNNEL_ABRT flags are added to properly handle
the tunnel mode in the H2 mux. The first one is used to detect tunnel
establishment or fully established tunnel. The second one is used to abort a
tunnel attempt. It is the first commit having as a goal to fix tunnel
establishment between H1 and H2 muxes.

There is a subtlety in h2_rcv_buf(). CS_FL_EOS flag is added on the
conn-stream when ES is received on a tunneled stream. It really reflects the
conn-stream state and is mandatory for next commits.
2021-01-28 16:37:14 +01:00
Christopher Faulet
8989942cfc BUG/MINOR: h2/mux-h2: Reject 101 responses with a PROTOCOL_ERROR h2s error
As stated in the RFC7540, section 8.1.1, the HTTP/2 removes support for the
101 informational status code. Thus a PROTOCOL_ERROR is now returned to the
server if a 101-switching-protocols response is received. Thus, the server
connection is aborted.

This patch may be backported as far as 2.0.
2021-01-28 16:36:40 +01:00
Willy Tarreau
b2551057af CLEANUP: include: tree-wide alphabetical sort of include files
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.
2020-06-11 10:18:59 +02:00
Willy Tarreau
f268ee8795 REORG: include: split global.h into haproxy/global{,-t}.h
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.
2020-06-11 10:18:58 +02:00
Willy Tarreau
bf0731491b REORG: include: move common/h2.h to haproxy/h2.h
No change was performed, the file is only included from C files and
currently doesn't need to be split into types+functions.
2020-06-11 10:18:57 +02:00
Willy Tarreau
16f958c0e9 REORG: include: split common/htx.h into haproxy/htx{,-t}.h
Most of the file was a large set of HTX elements manipulation functions
and few types, so splitting them allowed to further reduce dependencies
and shrink the build time. Doing so revealed that a few files (h2.c,
mux_pt.c) needed haproxy/buf.h and were previously getting it through
htx.h. They were fixed.
2020-06-11 10:18:57 +02:00
Willy Tarreau
0017be0143 REORG: include: split common/http-hdr.h into haproxy/http-hdr{,-t}.h
There's only one struct and 2 inline functions. It could have been
merged into http.h but that would have added a massive dependency on
the hpack parts for nothing, so better keep it this way since hpack
is already freestanding and portable.
2020-06-11 10:18:57 +02:00
Willy Tarreau
cd72d8c981 REORG: include: split common/http.h into haproxy/http{,-t}.h
So the enums and structs were placed into http-t.h and the functions
into http.h. This revealed that several files were dependeng on http.h
but not including it, as it was silently inherited via other files.
2020-06-11 10:18:57 +02:00
Willy Tarreau
eb6f701b99 REORG: include: move ist.h from common/ to import/
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.
2020-06-11 10:18:56 +02:00
Willy Tarreau
4c7e4b7738 REORG: include: update all files to use haproxy/api.h or api-t.h if needed
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.
2020-06-11 10:18:42 +02:00
Ilya Shipitsin
6fb0f2148f CLEANUP: assorted typo fixes in the code and comments
This is sixth iteration of typo fixes
2020-04-02 16:25:45 +02:00
Willy Tarreau
fd2658c0c6 BUG/MINOR: h2: reject again empty :path pseudo-headers
Since commit 92919f7fd5 ("MEDIUM: h2: make the request parser rebuild
a complete URI") we make sure to rebuild a complete URI. Unfortunately
the test for an empty :path pseudo-header that is mandated by #8.1.2.3
appened to be performed on the URI before this patch, which is never
empty anymore after being rebuilt, causing h2spec to complain :

  8. HTTP Message Exchanges
    8.1. HTTP Request/Response Exchange
      8.1.2. HTTP Header Fields
        8.1.2.3. Request Pseudo-Header Fields
          - 1: Sends a HEADERS frame with empty ":path" pseudo-header field
            -> The endpoint MUST respond with a stream error of type PROTOCOL_ERROR.
               Expected: GOAWAY Frame (Error Code: PROTOCOL_ERROR)
                         RST_STREAM Frame (Error Code: PROTOCOL_ERROR)
                         Connection closed
                 Actual: DATA Frame (length:0, flags:0x01, stream_id:1)

It's worth noting that this error doesn't trigger when calling h2spec
with a timeout as some scripts do, which explains why it wasn't detected
after the patch above.

This fixes one half of issue #471 and should be backported to 2.1.
2020-02-26 13:56:24 +01:00
Willy Tarreau
146f53ae7e BUG/MAJOR: h2: make header field name filtering stronger
Tim Düsterhus found that the amount of sanitization we perform on HTTP
header field names received in H2 is insufficient. Currently we reject
upper case letters as mandated by RFC7540#8.1.2, but section 10.3 also
requires that intermediaries translating streams to HTTP/1 further
refine the filtering to also reject invalid names (which means any name
that doesn't match a token). There is a small trick here which is that
the colon character used to start pseudo-header names doesn't match a
token, so pseudo-header names fall into that category, thus we have to
swap the pseudo-header name lookup with this check so that we only check
from the second character (past the ':') in case of pseudo-header names.

Another possibility could have been to perform this check only in the
HTX-to-H1 trancoder but doing would still expose the configured rules
and logs to such header names.

This fix must be backported as far as 1.8 since this bug could be
exploited and serve as the base for an attack. In 2.0 and earlier,
functions h2_make_h1_request() and h2_make_h1_trailers() must also
be adapted to sanitize requests coming in legacy mode.
2019-11-25 11:11:32 +01:00