If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
After sending the GOAWAY frame, a connection is now closed using
the lingering close mechanism.
This allows for the reliable delivery of the GOAWAY frames, while
also fixing connection resets observed when http2_max_requests is
reached (ticket #1250), or with graceful shutdown (ticket #1544),
when some additional data from the client is received on a fully
closed connection.
For HTTP/2, the settings lingering_close, lingering_timeout, and
lingering_time are taken from the "server" level.
Previously, the expression (ch & 0x7f) was promoted to a signed integer.
Depending on the platform, the size of this integer could be less than 8 bytes,
leading to overflow when handling the higher bits of the result. Also, sign
bit of this integer could be replicated when adding to the 64-bit st->value.
Previously errors led only to closing streams.
To simplify closing QUIC connection from a QUIC stream context, new macro
ngx_http_v3_finalize_connection() is introduced. It calls
ngx_quic_finalize_connection() for the parent connection.
The function finalizes QUIC connection with an application protocol error
code and sends a CONNECTION_CLOSE frame with type=0x1d.
Also, renamed NGX_QUIC_FT_CONNECTION_CLOSE2 to NGX_QUIC_FT_CONNECTION_CLOSE_APP.
Previously dynamic table was not functional because of zero limit on its size
set by default. Now the following changes enable it:
- new directives to set SETTINGS_QPACK_MAX_TABLE_CAPACITY and
SETTINGS_QPACK_BLOCKED_STREAMS
- send settings with SETTINGS_QPACK_MAX_TABLE_CAPACITY and
SETTINGS_QPACK_BLOCKED_STREAMS to the client
- send Insert Count Increment to the client
- send Header Acknowledgement to the client
- evict old dynamic table entries on overflow
- decode Required Insert Count from client
- block stream if Required Insert Count is not reached
Using SSL_CTX_set_verify(SSL_VERIFY_PEER) implies that OpenSSL will
send a certificate request during an SSL handshake, leading to unexpected
certificate requests from browsers as long as there are any client
certificates installed. Given that ngx_ssl_trusted_certificate()
is called unconditionally by the ngx_http_ssl_module, this affected
all HTTPS servers. Broken by 699f6e55bbb4 (not released yet).
Fix is to set verify callback in the ngx_ssl_trusted_certificate() function
without changing the verify mode.
Client streams may send literal strings which are now limited in size by the
new directive. The default value is 4096.
The directive is similar to HTTP/2 directive http2_max_field_size.
So that connections are protected from failing from on-path attacks.
Decryption failure of long packets used during handshake still leads
to connection close since it barely makes sense to handle them there.
A previously used undefined error code is now replaced with the generic one.
Note that quic-transport prescribes keeping connection intact, discarding such
QUIC packets individually, in the sense that coalesced packets could be there.
This is selectively handled in the next change.
The patch removes remnants of the old state tracking mechanism, which did
not take into account assimetry of read/write states and was not very
useful.
The encryption state now is entirely tracked using SSL_quic_read/write_level().
quic-transport draft 29:
section 7:
* authenticated negotiation of an application protocol (TLS uses
ALPN [RFC7301] for this purpose)
...
Endpoints MUST explicitly negotiate an application protocol. This
avoids situations where there is a disagreement about the protocol
that is in use.
section 8.1:
When using ALPN, endpoints MUST immediately close a connection (see
Section 10.3 of [QUIC-TRANSPORT]) with a no_application_protocol TLS
alert (QUIC error code 0x178; see Section 4.10) if an application
protocol is not negotiated.
Changes in ngx_quic_close_quic() function are required to avoid attempts
to generated and send packets without proper keys, what happens in case
of failed ALPN check.
quic-transport draft 29, section 14:
QUIC depends upon a minimum IP packet size of at least 1280 bytes.
This is the IPv6 minimum size [RFC8200] and is also supported by most
modern IPv4 networks. Assuming the minimum IP header size, this
results in a QUIC maximum packet size of 1232 bytes for IPv6 and 1252
bytes for IPv4.
Since the packet size can change during connection lifetime, the
ngx_quic_max_udp_payload() function is introduced that currently
returns minimal allowed size, depending on address family.
quic-tls, 8.2:
The quic_transport_parameters extension is carried in the ClientHello
and the EncryptedExtensions messages during the handshake. Endpoints
MUST send the quic_transport_parameters extension; endpoints that
receive ClientHello or EncryptedExtensions messages without the
quic_transport_parameters extension MUST close the connection with an
error of type 0x16d (equivalent to a fatal TLS missing_extension
alert, see Section 4.10).
Clearing cache based on free space left on a file system is
expected to allow better disk utilization in some cases, notably
when disk space might be also used for something other than nginx
cache (including nginx own temporary files) and while loading
cache (when cache size might be inaccurate for a while, effectively
disabling max_size cache clearing).
Based on a patch by Adam Bambuch.
With XFS, using "allocsize=64m" mount option results in large preallocation
being reported in the st_blocks as returned by fstat() till the file is
closed. This in turn results in incorrect cache size calculations and
wrong clearing based on max_size.
To avoid too aggressive cache clearing on such volumes, st_blocks values
which result in sizes larger than st_size and eight blocks (an arbitrary
limit) are no longer trusted, and we use st_size instead.
The ngx_de_fs_size() counterpart is intentionally not modified, as
it is used on closed files and hence not affected by this problem.
NFS on Linux is known to report wsize as a block size (in both f_bsize
and f_frsize, both in statfs() and statvfs()). On the other hand,
typical file system block sizes on Linux (ext2/ext3/ext4, XFS) are limited
to pagesize. (With FAT, block sizes can be at least up to 512k in
extreme cases, but this doesn't really matter, see below.)
To avoid too aggressive cache clearing on NFS volumes on Linux, block
sizes larger than pagesize are now ignored.
Note that it is safe to ignore large block sizes. Since 3899:e7cd13b7f759
(1.0.1) cache size is calculated based on fstat() st_blocks, and rounding
to file system block size is preserved mostly for Windows.
Note well that on other OSes valid block sizes seen are at least up
to 65536. In particular, UFS on FreeBSD is known to work well with block
and fragment sizes set to 65536.
When validating second and further certificates, ssl callback could be called
twice to report the error. After the first call client connection is
terminated and its memory is released. Prior to the second call and in it
released connection memory is accessed.
Errors triggering this behavior:
- failure to create the request
- failure to start resolving OCSP responder name
- failure to start connecting to the OCSP responder
The fix is to rearrange the code to eliminate the second call.
The flush flag was not set when forwarding the request body to the uwsgi
server. When using uwsgi_pass suwsgi://..., this causes the uwsgi server
to wait indefinitely for the request body and eventually time out due to
SSL buffering.
This is essentially the same change as 4009:3183165283cc, which was made
to ngx_http_proxy_module.c.
This will fix the uwsgi bug https://github.com/unbit/uwsgi/issues/1490.
This is a temporary workaround, proper retransmission mechanism based on
quic-recovery rfc draft is yet to be implemented.
Currently hardcoded value is too small for real networks. The patch
sets static PTO, considering rtt of ~333ms, what gives about 1s.
