Before 1.3.9 an attempt to read body in a subrequest only caused problems
if body wasn't already read or discarded in a main request. Starting with
1.3.9 it might also cause problems if body was discarded by a main request
before subrequest start.
Fix is to just ignore attempts to read request body in a subrequest, which
looks like right thing to do anyway.
To avoid further breaks it's now done properly, all the dependencies
are now passed to Makefile.PL. While here, fixed include list passed to
Makefile.PL to use Makefile variables rather than a list expanded during
configure.
Sorting of upstream servers by their weights is not required by
current balancing algorithms.
This will likely change mapping to backends served by ip_hash
weighted upstreams.
And corresponding variable $connections_waiting was added.
Previously, waiting connections were counted as the difference between
active connections and the sum of reading and writing connections.
That made it impossible to count more than one request in one connection
as reading or writing (as is the case for SPDY).
Also, we no longer count connections in handshake state as waiting.
This should improve behavior under deficiency of connections.
Since SSL handshake usually takes significant amount of time,
we exclude connections from reusable queue during this period
to avoid premature flush of them.
If proxy_pass to a host with dynamic resolution was used to handle
a subrequest, and host resolution failed, the main request wasn't run
till something else happened on the connection. E.g. request to "/zzz"
with the following configuration hanged:
addition_types *;
resolver 8.8.8.8;
location /test {
set $ihost xxx;
proxy_pass http://$ihost;
}
location /zzz {
add_after_body /test;
return 200 "test";
}
Report and original version of the patch by Lanshun Zhou,
http://mailman.nginx.org/pipermail/nginx-devel/2013-March/003476.html.
Code to reuse of r->request_body->buf in upstream module assumes it's
dedicated buffer, hence after 1.3.9 (r4931) it might reuse r->header_in
if client_body_in_file_only was set, resulting in original request
corruption. It is considered to be safer to always create a dedicated
buffer for rb->bufs to avoid such problems.
After introduction of chunked request body handling in 1.3.9 (r4931),
r->request_body->bufs buffers have b->start pointing to original buffer
start (and b->pos pointing to real data of this particular buffer).
While this is ok as per se, it caused bad things (usually original request
headers included before the request body) after reinit of the request
chain in ngx_http_upstream_reinit() while sending the request to a next
upstream server (which used to do b->pos = b->start for each buffer
in the request chain).
Patch by Piotr Sikora.
If c->recv() returns 0 there is no sense in using ngx_socket_errno for
logging, its value meaningless. (The code in question was copied from
ngx_http_keepalive_handler(), but ngx_socket_errno makes sense there as it's
used as a part of ECONNRESET handling, and the c->recv() call is preceeded
by the ngx_set_socket_errno(0) call.)
In r2411 setting of NGX_HTTP_GZIP_BUFFERED in c->buffered was moved from
ngx_http_gzip_filter_deflate_start() to ngx_http_gzip_filter_buffer() since
it was always called first. But in r2543 the "postpone_gzipping" directive
was introduced, and if postponed gzipping is disabled (the default setting),
ngx_http_gzip_filter_buffer() is not called at all.
We must always set NGX_HTTP_GZIP_BUFFERED after the start of compression
since there is always a trailer that is buffered.
There are no known cases when it leads to any problem with current code.
But we already had troubles in upcoming SPDY implementation.
Not only this is useful for the upcoming SPDY support, but it can
also help to improve HTTPS performance by enabling TLS False Start
in Chrome/Chromium browsers [1]. So, we always enable NPN for HTTPS
if it is supported by OpenSSL.
[1] http://www.imperialviolet.org/2012/04/11/falsestart.html
The c->single_connection was intended to be used as lock mechanism
to serialize modifications of request object from several threads
working with client and upstream connections. The flag is redundant
since threads in nginx have never been used that way.
In Linux 2.6.32, TCP_DEFER_ACCEPT was changed to accept connections
after the deferring period is finished without any data available.
(Reading from the socket returns EAGAIN in this case.)
Since in nginx TCP_DEFER_ACCEPT is set to "post_accept_timeout", we
do not need to wait longer if deferred accept returns with no data.
Previously, only the first request in a connection used timeout
value from the "client_header_timeout" directive while reading
header. All subsequent requests used "keepalive_timeout" for
that.
It happened because timeout of the read event was set to the
value of "keepalive_timeout" in ngx_http_set_keepalive(), but
was not removed when the next request arrived.
Previously, we always created an object and logged 400 (Bad Request)
in access log if a client closed connection without sending any data.
Such a connection was counted as "reading".
Since it's common for modern browsers to behave like this, it's no
longer considered an error if a client closes connection without
sending any data, and such a connection will be counted as "waiting".
Now, we do not log 400 (Bad Request) and keep memory footprint as
small as possible.
Previously, it was allocated from a connection pool and
was selectively freed for an idle keepalive connection.
The goal is to put coupled things in one chunk of memory,
and to simplify handling of request objects.
According to RFC 6066, client is not supposed to request a different server
name at the application layer. Server implementations that rely upon these
names being equal must validate that a client did not send a different name
in HTTP request. Current versions of Apache HTTP server always return 400
"Bad Request" in such cases.
There exist implementations however (e.g., SPDY) that rely on being able to
request different host names in one connection. Given this, we only reject
requests with differing host names if verification of client certificates
is enabled in a corresponding server configuration.
An example of configuration that might not work as expected:
server {
listen 433 ssl default;
return 404;
}
server {
listen 433 ssl;
server_name example.org;
ssl_client_certificate org.cert;
ssl_verify_client on;
}
server {
listen 433 ssl;
server_name example.com;
ssl_client_certificate com.cert;
ssl_verify_client on;
}
Previously, a client was able to request example.com by presenting
a certificate for example.org, and vice versa.
Not only this is consistent with a case without SNI, but this also
prevents abusing configurations that assume that the $host variable
is limited to one of the configured names for a server.
An example of potentially unsafe configuration:
server {
listen 443 ssl default_server;
...
}
server {
listen 443;
server_name example.com;
location / {
proxy_pass http://$host;
}
}
Note: it is possible to negotiate "example.com" by SNI, and to request
arbitrary host name that does not exist in the configuration above.
Previously, this was done only after the whole request header
was parsed, and if an error occurred earlier then the request
was processed in the default server (or server chosen by SNI),
while r->headers_in.server might be set to the value from the
Host: header or host from request line.
r->headers_in.server is in turn used for $host variable and
in HTTP redirects if "server_name_in_redirect" is disabled.
Without the change, configurations that rely on this during
error handling are potentially unsafe if SNI is used.
This change also allows to use server specific settings of
"underscores_in_headers", "ignore_invalid_headers", and
"large_client_header_buffers" directives for HTTP requests
and HTTPS requests without SNI.
The request object will not be created until SSL handshake is complete.
This simplifies adding another connection handler that does not need
request object right after handshake (e.g., SPDY).
There are also a few more intentional effects:
- the "client_header_buffer_size" directive will be taken from the
server configuration that was negotiated by SNI;
- SSL handshake errors and timeouts are not logged into access log
as bad requests;
- ngx_ssl_create_connection() is not called until the first byte of
ClientHello message was received. This also decreases memory
consumption if plain HTTP request is sent to SSL socket.
Previously, only the first request in a connection was assigned the
configuration selected by SNI. All subsequent requests initially
used the default server's configuration, ignoring SNI, which was
wrong.
Now all subsequent requests in a connection will initially use the
configuration selected by SNI. This is done by storing a pointer
to configuration in http connection object. It points to default
server's configuration initially, but changed upon receipt of SNI.
(The request's configuration can be further refined when parsing
the request line and Host: header.)
This change was not made specific to SNI as it also allows slightly
faster access to configuration without the request object.
This change helps to decouple ngx_http_ssl_servername() from the request
object.
Note: now we close connection in case of error during server name lookup
for request. Previously, we did so only for HTTP/0.9 requests.
In case multiple "Cache-Control" headers are sent to a client,
multiple values in $sent_http_cache_control were incorrectly
split by a semicolon. Now they are split by a comma.
In case of error in the read event handling we close a connection
by calling ngx_http_close_connection(), that also destroys connection
pool. Thereafter, an attempt to free a buffer (added in r4892) that
was allocated from the pool could cause SIGSEGV and is meaningless
as well (the buffer already freed with the pool).
It was added in r2717 and no longer needed since r2721,
where the termination was added to ngx_shm_alloc() and
ngx_init_zone_pool(). So then it only corrupts error
messages about ivalid zones.
This allows to proxy WebSockets by using configuration like this:
location /chat/ {
proxy_pass http://backend;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}
Connection upgrade is allowed as long as it was requested by a client
via the Upgrade request header.
If fastcgi end request record was split between several network packets,
with fastcgi_keep_conn it was possible that connection was saved in incorrect
state (e.g. with padding bytes not yet read).
Checks for f->padding before state transitions make code hard to follow,
remove them and make sure we always do another loop iteration after
f->state is set to ngx_http_fastcgi_st_padding.
With fastcgi_keep_conn it was possible that connection was closed after
FCGI_STDERR record with zero padding and without any further data read yet.
This happended as f->state was set to ngx_http_fastcgi_st_padding and then
"break" happened, resulting in p->length being set to f->padding, i.e. 0
(which in turn resulted in connection close).
Fix is to make sure we continue the loop after f->state is set.
After introduction of chunked request body reading support in 1.3.9 (r4931),
the rb->bufs wasn't set if request body was fully preread while calling the
ngx_http_read_client_request_body() function.
Reported by Yichun Zhang (agentzh).
The "secure_link_secret" directive was always inherited from the outer
configuration level even when "secure_link" and "secure_link_md5" were
specified on the inner level.
Before the patch if proxy_method was specified at http{} level the code
to add trailing space wasn't executed, resulting in incorrect requests
to upstream.
The "proxy_bind", "fastcgi_bind", "uwsgi_bind", "scgi_bind" and
"memcached_bind" directives are now inherited; inherited value
can be reset by the "off" parameter. Duplicate directives are
now detected. Parameter value can now contain variables.
Upstreams created by "proxy_pass" with IP address and no port were
broken in 1.3.10, by not initializing port in u->sockaddr.
API change: ngx_parse_url() was modified to always initialize port
(in u->sockaddr and in u->port), even for the u->no_resolve case;
ngx_http_upstream() and ngx_http_upstream_add() were adopted.
Previously, "default" was equivalent to specifying 0.0.0.0/0, now
it's equivalent to specifying both 0.0.0.0/0 and ::/0 (if support
for IPv6 is enabled) with the same value.
The code refactored in a way to call custom handler that can do appropriate
cleanup work (if any), like flushing buffers, finishing compress streams,
finalizing connections to log daemon, etc..
Previously a new buffer was allocated for every "access_log" directive with the
same file path and "buffer=" parameters, while only one buffer per file is used.
Configurations like
location /i/ {
image_filter resize 200 200;
image_filter rotate 180;
location /i/foo/ {
image_filter resize 200 200;
}
}
resulted in rotation incorrectly applied in the location /i/foo, without
any way to clear it. Fix is to handle conf->angle/conf->acv consistently
with other filter variables and do not try to inherit them if there are
transformations defined for current location.
The image_filter_jpeg_quality, image_filter_sharpen and "image_filter rotate"
were inherited incorrectly if a directive with variables was defined, and
then redefined to a literal value, i.e. in configurations like
image_filter_jpeg_quality $arg_q;
location / {
image_filter_jpeg_quality 50;
}
Patch by Ian Babrou, with minor changes.
An incorrect memLevel (lower than 1) might be passed to deflateInit2() if the
"gzip_hash" directive is set to a value less than the value of "gzip_window"
directive. This resulted in "deflateInit2() failed: -2" alert and an empty
reply.
Configuration like
location / {
set $true 1;
if ($true) {
proxy_pass http://backend;
}
if ($true) {
# nothing
}
}
resulted in segmentation fault due to NULL pointer dereference as the
upstream configuration wasn't initialized in an implicit location created
by the last if(), but the r->content_handler was set due to first if().
Instead of committing a suicide by dereferencing a NULL pointer, return
500 (Internal Server Error) in such cases, i.e. if uscf is NULL. Better
fix would be to avoid such cases by fixing the "if" directive handling,
but it's out of scope of this patch.
Prodded by Piotr Sikora.
If write events are not blocked, an extra write event might happen for
various reasons (e.g. as a result of a http pipelining), resulting in
incorrect body being passed to a post handler.
The problem manifested itself with the dav module only, as this is
the only module which reads the body from a content phase handler (in
contrast to exclusive content handlers like proxy). Additionally, dav
module used to dump core in such situations due to ticket #238.
See reports here:
http://mailman.nginx.org/pipermail/nginx-devel/2012-November/002981.htmlhttp://serverfault.com/questions/449195/nginx-webdav-server-with-auth-request
While discarding chunked request body in some cases after detecting
request body corruption no error was returned, while it was possible
to correctly return 400 Bad Request. If error is detected too late,
make sure to properly close connection.
Additionally, in ngx_http_special_response_handler() don't return body
of 500 Internal Server Error to a client if ngx_http_discard_request_body()
fails, but disable keepalive and continue.
Even if there is no preread data, make sure to always call
ngx_http_discard_request_body_filter() in case of chunked request
body to initialize r->headers_in.content_length_n for later use.
An attempt to call ngx_handle_read_event() before actually reading
data from a socket might result in read event being disabled, which is
wrong. Catched by body.t test on Solaris.
The r->main->count reference counter was always incremented in
ngx_http_read_client_request_body(), while it is only needs to be
incremented on positive returns.
The $request_body variable was assuming there can't be more than two
buffers. While this is currently true due to request body reading
implementation details, this is not a good thing to depend on and may
change in the future.
It is not about "Method" but a generic message, and is expected to be used
e.g. if specified Transfer-Encoding is not supported. Fixed message to
match RFC 2616.
Additionally, disable keepalive on such errors as we won't be able to read
request body correctly if we don't understand Transfer-Encoding used.
If request body reading happens with different options it's possible
that there will be no r->request_body->temp_file available (or even
no r->request_body available if body was discarded). Return internal
server error in this case instead of committing suicide by dereferencing
a null pointer.
Pending EOF might be reported on both read and write events, whichever
comes first, so check both of them.
Patch by Yichun Zhang (agentzh), slightly modified.
If an upstream block was defined with the only server marked as
"down", e.g.
upstream u {
server 127.0.0.1:8080 down;
}
an attempt was made to contact the server despite the "down" flag.
It is believed that immediate 502 response is better in such a
case, and it's also consistent with what is currently done in case
of multiple servers all marked as "down".
Input filter might free a buffer if there is no data in it, and in case
of first buffer (used for cache header and request header, aka p->buf_to_file)
this resulted in cache corruption. Buffer memory was reused to read upstream
response before headers were written to disk.
Fix is to avoid moving pointers in ngx_event_pipe_add_free_buf() to a buffer
start if we were asked to free a buffer used by p->buf_to_file.
This fixes occasional cache file corruption, usually resulted
in "cache file ... has md5 collision" alerts.
Reported by Anatoli Marinov.
idle connections.
This behaviour is consistent with the ngx_http_set_keepalive() function and it
should decrease memory usage in some cases (especially if epoll/rtsig is used).
This parameter allows to don't require certificate to be signed by
a trusted CA, e.g. if CA certificate isn't known in advance, like in
WebID protocol.
Note that it doesn't add any security unless the certificate is actually
checked to be trusted by some external means (e.g. by a backend).
Patch by Mike Kazantsev, Eric O'Connor.
OCSP response verification is now switched off by default to simplify
configuration, and the ssl_stapling_verify allows to switch it on.
Note that for stapling OCSP response verification isn't something required
as it will be done by a client anyway. But doing verification on a server
allows to mitigate some attack vectors, most notably stop an attacker from
presenting some specially crafted data to all site clients.
This includes the ssl_stapling_responder directive (defaults to OCSP
responder set in certificate's AIA extension).
OCSP response for a given certificate is requested once we get at least
one connection with certificate_status extension in ClientHello, and
certificate status won't be sent in the connection in question. This due
to limitations in the OpenSSL API (certificate status callback is blocking).
Note: SSL_CTX_use_certificate_chain_file() was reimplemented as it doesn't
allow to access the certificate loaded via SSL_CTX.
Very basic version without any OCSP responder query code, assuming valid
DER-encoded OCSP response is present in a ssl_stapling_file configured.
Such file might be produced with openssl like this:
openssl ocsp -issuer root.crt -cert domain.crt -respout domain.staple \
-url http://ocsp.example.com
The directive allows to specify additional trusted Certificate Authority
certificates to be used during certificate verification. In contrast to
ssl_client_certificate DNs of these cerificates aren't sent to a client
during handshake.
Trusted certificates are loaded regardless of the fact whether client
certificates verification is enabled as the same certificates will be
used for OCSP stapling, during construction of an OCSP request and for
verification of an OCSP response.
The same applies to a CRL (which is now always loaded).
With "always" gzip static returns gzipped content in all cases, without
checking if client supports it. It is useful if there are no uncompressed
files on disk anyway.
This directive allows to test desired flag as returned by memcached and
sets Content-Encoding to gzip if one found.
This is reimplementation of patch by Tomash Brechko as available on
http://openhack.ru/. It should be a bit more correct though (at least
I think so). In particular, it doesn't try to detect if we are able to
gunzip data, but instead just sets correct Content-Encoding.
The rbtree used in ngx_http_limit_req_module has two level of keys, the top is
hash, and the next is the value string itself. However, when inserting a new
node, only hash has been set, while the value string has been left empty.
The bug was introduced in r4419 (1.1.14).
Found by Charles Chen.
The "include" directive should be able to include multiple files if
given a filename mask. Fixed this to work for "include" directives
inside the "map" or "types" blocks. The "include" directive inside
the "geo" block is still not fixed.
Previous code incorrectly used ctx->var_values as an array of pointers to
ngx_http_variable_value_t, but the array contains structures, not pointers.
Additionally, ctx->var_values inspection failed to properly set var on
match.
There is a general consensus that this change results in better
consistency between different operating systems and differently
tuned operating systems.
Note: this changes the width and meaning of the ipv6only field
of the ngx_listening_t structure. 3rd party modules that create
their own listening sockets might need fixing.
Hide headers and pass headers arrays might not be inherited correctly
into a nested location, e.g. in configuration like
server {
proxy_hide_header X-Foo;
location / {
location /nested/ {
proxy_pass_header X-Pad;
}
}
}
the X-Foo header wasn't hidden in the location /nested/.
Reported by Konstantin Svist,
http://mailman.nginx.org/pipermail/nginx-ru/2012-July/047555.html
the end (closes#187). Failure to do so could result in several listen
sockets to be created instead of only one listening on wildcard address.
Reported by Roman Odaisky.
It allows to disable generation of nginx's own entity tags, while
still handling ETags in cache properly. This may be useful e.g.
if one want to serve static files from servers with different ETag
generation algorithms.
This includes handling of ETag headers (if present in a response) with
basic support for If-Match, If-None-Match conditionals in not modified
filter.
Note that the "r->headers_out.last_modified_time == -1" check in the not
modified filter is left as is intentionally. It's to prevent handling
of If-* headers in case of proxy without cache (much like currently
done with If-Modified-Since).
This makes code more extendable. The only functional change is when
If-Modified-Since and If-Unmodified-Since are specified together, the
case which is explicitly left undefined by RFC 2616. The new behaviour
is to respect them both, which seems better.
If modification time isn't known, skip range processing and return full
entity body instead of just ignoring If-Range. Ignoring If-Range isn't
safe as client will assume entity wasn't changed since time specified.
The original idea was to optimize edge cases in case of interchangeable
backends, i.e. don't establish a new connection if we have any one
cached. This causes more harm than good though, as it screws up
underlying balancer's idea about backends used and may result in
various unexpected problems.
Number of entries in stsc atom was wrong if we've added an entry to
split a chunk.
Additionally, there is no need to add an entry if we are going to split
last chunk in an entry, it's enough to update the entry we already have.
Previously new entry was added and old one was left as is, resulting in
incorrect entry with zero chunks which might confuse some software.
Contains response status code as a 3-digit integer
(with leading zeroes if necessary), or one of the following values:
000 - response status code has not yet been assigned
009 - HTTP/0.9 request is being processed
There are too many problems with special NTFS streams, notably "::$data",
"::$index_allocation" and ":$i30:$index_allocation".
For now we don't reject all URIs with ":" like Apache does as there are no
good reasons seen yet, and there are multiple programs using it in URLs
(e.g. MediaWiki).
Windows treats "/directory./" identical to "/directory/". Do the same
when working on Windows. Note that the behaviour is different from one
with last path component (where multiple spaces and dots are ignored by
Windows).
Removed duplicate call of ngx_http_upstream_init_round_robin_peer()
overlooked during code changes. Rewritten "return lcp->free_rr_peer(...)"
as MSVC doesn't like it.
If the "proxy_cookie_domain" or "proxy_cookie_path" directive is used and there
are no matches in Set-Cookie header then ngx_http_proxy_rewrite_cookie() returns
NGX_DECLINED to indicate that the header was not rewritten. Returning this value
further from the upstream headers copy handler resulted in 500 error response.
See here for report:
http://mailman.nginx.org/pipermail/nginx/2012-May/033858.html
If variable was indexed in previous configuration but not in current
one, the NGX_HTTP_VAR_INDEXED flag was left set and confused
ngx_http_get_variable().
Patch by Yichun Zhang (agentzh), slightly modified.
Example configuration to reproduce:
location /image/ {
error_page 415 = /zero;
image_filter crop 100 100;
proxy_pass http://127.0.0.1:8080;
proxy_store on;
}
location /zero {
return 204;
}
The problem appeared if upstream returned (big enough) non-image file,
causing 415 to be generated by image filter.
The module now supports recursive search of client address through the
chain of trusted proxies (closes#100), in the same scope as the geo
module. Proxies are listed by the "geoip_proxy" directive, recursive
search is enabled by the "geoip_proxy_recursive" directive. IPv6 is
partially supported: proxies may be specified with IPv6 addresses.
Example:
geoip_country .../GeoIP.dat;
geoip_proxy 127.0.0.1;
geoip_proxy ::1;
geoip_proxy 10.0.0.0/8;
geoip_proxy_recursive on;
The module now supports recursive search of client address through
the chain of trusted proxies, controlled by the "proxy_recursive"
directive in the "geo" block. It also gets partial IPv6 support:
now proxies may be specified with IPv6 addresses.
Example:
geo $test {
...
proxy 127.0.0.1;
proxy ::1;
proxy_recursive;
}
There's also a slight change in behavior. When original client
address (as specified by the "geo" directive) is one of the
trusted proxies, and the value of the X-Forwarded-For request
header cannot not be parsed as a valid address, an original client
address will be used for lookup. Previously, 255.255.255.255 was
used in this case.
The module now supports recursive search of client address through
the chain of trusted proxies, controlled by the "real_ip_recursive"
directive (closes#2). It also gets full IPv6 support (closes#44)
and canonical value of the $client_addr variable on address change.
Example:
real_ip_header X-Forwarded-For;
set_real_ip_from 127.0.0.0/8;
set_real_ip_from ::1;
set_real_ip_from unix:;
real_ip_recursive on;
On input it takes an original address, string in the X-Forwarded-For format
and its length, list of trusted proxies, and a flag indicating to perform
the recursive search. On output it returns NGX_OK and the "deepest" valid
address in a chain, or NGX_DECLINED. It supports AF_INET and AF_INET6.
Additionally, original address and/or proxy may be specified as AF_UNIX.
Due to weight being set to 0 for down peers, order of peers after sorting
wasn't the same as without the "down" flag (with down peers at the end),
resulting in client rebalancing for clients on other servers. The only
rebalancing which should happen after adding "down" to a server is one
for clients on the server.
The problem was introduced in r1377 (which fixed endless loop by setting
weight to 0 for down servers). The loop is no longer possible with new
smooth algorithm, so preserving original weight is safe.
For edge case weights like { 5, 1, 1 } we now produce { a, a, b, a, c, a, a }
sequence instead of { c, b, a, a, a, a, a } produced previously.
Algorithm is as follows: on each peer selection we increase current_weight
of each eligible peer by its weight, select peer with greatest current_weight
and reduce its current_weight by total number of weight points distributed
among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of
current_weight's:
a b c
0 0 0 (initial state)
5 1 1 (a selected)
-2 1 1
3 2 2 (a selected)
-4 2 2
1 3 3 (b selected)
1 -4 3
6 -3 4 (a selected)
-1 -3 4
4 -2 5 (c selected)
4 -2 -2
9 -1 -1 (a selected)
2 -1 -1
7 0 0 (a selected)
0 0 0
To preserve weight reduction in case of failures the effective_weight
variable was introduced, which usually matches peer's weight, but is
reduced temporarily on peer failures.
This change also fixes loop with backup servers and proxy_next_upstream
http_404 (ticket #47), and skipping alive upstreams in some cases if there
are multiple dead ones (ticket #64).
With r->filter_finalize set the ngx_http_finalize_connection() wasn't
called from ngx_http_finalize_request() called with NGX_OK, resulting in
r->main->count not being decremented, thus causing request hang in some
rare situations.
See here for more details:
http://mailman.nginx.org/pipermail/nginx-devel/2012-May/002190.html
Patch by Yichun Zhang (agentzh).
The following code resulted in incorrect escaping of uri and possible
segfault:
location / {
rewrite ^(.*) $1?c=$1;
return 200 "$uri";
}
If there were arguments in a rewrite's replacement string, and length was
actually calculated (due to duplicate captures as in the example above,
or variables present), the is_args flag was set and incorrectly copied
after length calculation. This resulted in escaping applied to the uri part
of the replacement, resulting in incorrect escaping. Additionally, buffer
was allocated without escaping expected, thus this also resulted in buffer
overrun and possible segfault.
Padding was incorrectly ignored on end request, empty stdout and stderr
fastcgi records. This resulted in protocol desynchronization if fastcgi
application used these records with padding for some reason.
Reported by Ilia Vinokurov.
Failing to do so results in problems if 400 or 414 requests are
redirected to fastcgi/scgi/uwsgi upstream, as well as after invalid
headers got from upstream. This was already fixed for proxy in r3478,
but fastcgi (the only affected protocol at that time) was missed.
Reported by Matthieu Tourne.
On internal redirects this happens via ngx_http_handler() call, which is
not called on named location redirect. As a result incorrect write handler
remained (if previously set) and this might cause incorrect behaviour (likely
request hang).
Patch by Yichun Zhang (agentzh).
The proxy module context may be NULL in case of filter finalization
(e.g. by image_filter) followed by an internal redirect. This needs
some better handling, but for now just check if ctx is still here.
The problem occured if first uri in try_files was shorter than request uri,
resulting in reserve being 0 and hence allocation skipped. The bug was
introduced in r4584 (1.1.19).
Previous (incorrect) behaviour was to inherit ipv6 rules separately from
ipv4 ones. Now all rules are either inherited (if there are no rules
defined at current level) or not (if there are any rules defined).
Such upstreams cause CPU hog later in the code as number of peers isn't
expected to be 0. Currently this may happen either if there are only backup
servers defined in an upstream block, or if server with ipv6 address used
in an upstream block.
Note that "ctxt->loadsubset = 1" previously used isn't really correct as
ctxt->loadsubset is a bitfield now. The use of xmlCtxtUseOptions() with
XML_PARSE_DTDLOAD is believed to be a better way to do the same thing.
Patch by Laurence Rowe.
POSIX doesn't require it to be defined, and Debian GNU/Hurd doesn't define
it. Note that if there is no MAX_PATH defined we have to use realpath()
with NULL argument and free() the result.
The problem was introduced in 0.7.44 (r2589) during conversion to complex
values. Previously string.len included space for terminating NUL, but
with complex values it doesn't.
The bug in question is likely already fixed (though unfortunately we have
no information available as Apple's bugtracker isn't open), and the
workaround seems to be too pessimistic for modern versions of Safari
as well as other webkit-based browsers pretending to be Safari.
- Removed "hash" element from ngx_http_header_val_t which was always 1.
- Replaced NGX_HTTP_EXPIRES_* with ngx_http_expires_t enum type.
- Added prototype for ngx_http_add_header()
- Simplified ngx_http_set_last_modified().
This resulted in a disclosure of previously freed memory if upstream
server returned specially crafted response, potentially exposing
sensitive information.
Reported by Matthew Daley.
Embedded perl module assumes there is a space for terminating NUL character,
make sure to provide it in all situations by allocating one extra byte for
value buffer. Default ssi_value_length is reduced accordingly to
preserve 256 byte allocations.
While here, fixed another one byte value buffer overrun possible in
ssi_quoted_symbol_state.
Reported by Matthew Daley.
It wasn't enforced for a long time, and there are reports that people
use up to 100 simultaneous subrequests now. As this is a safety limit
to prevent loops, it's raised accordingly.
Previous code incorrectly assumed that nodes with identical keys are linked
together. This might not be true after tree rebalance.
Patch by Lanshun Zhou.
To completely disable symlinks (disable_symlinks on)
we use openat(O_NOFOLLOW) for each path component
to avoid races.
To allow symlinks with the same owner (disable_symlinks if_not_owner),
use openat() (followed by fstat()) and fstatat(AT_SYMLINK_NOFOLLOW),
and then compare uids between fstat() and fstatat().
As there is a race between openat() and fstatat() we don't
know if openat() in fact opened symlink or not. Therefore,
we have to compare uids even if fstatat() reports the opened
component isn't a symlink (as we don't know whether it was
symlink during openat() or not).
Default value is off, i.e. symlinks are allowed.
Nuke NGX_PARSE_LARGE_TIME, it's not used since 0.6.30. The only error
ngx_parse_time() can currently return is NGX_ERROR, check it explicitly
and make sure to cast it to appropriate type (either time_t or ngx_msec_t)
to avoid signedness warnings on platforms with unsigned time_t (notably QNX).
Now redirects to named locations are counted against normal uri changes
limit, and post_action respects this limit as well. As a result at least
the following (bad) configurations no longer trigger infinite cycles:
1. Post action which recursively triggers post action:
location / {
post_action /index.html;
}
2. Post action pointing to nonexistent named location:
location / {
post_action @nonexistent;
}
3. Recursive error page for 500 (Internal Server Error) pointing to
a nonexistent named location:
location / {
recursive_error_pages on;
error_page 500 @nonexistent;
return 500;
}
Without the protection, subrequest loop results in r->count overflow and
SIGSEGV. Protection was broken in 0.7.25.
Note that this also limits number of parallel subrequests. This
wasn't exactly the case before 0.7.25 as local subrequests were
completed directly.
See here for details:
http://nginx.org/pipermail/nginx-ru/2010-February/032184.html
Variables with the "not_found" flag set follow the same rules as ones with
the "valid" flag set. Make sure ngx_http_get_flushed_variable() will flush
non-cacheable variables with the "not_found" flag set.
This fixes at least one known problem with $args not available in a subrequest
(with args) when there were no args in the main request and $args variable was
queried in the main request (reported by Laurence Rowe aka elro on irc).
Also this eliminates unneeded call to ngx_http_get_indexed_variable() in
cacheable case (as it will return cached value anyway).
Temporary files might not be removed if the "proxy_store" or "fastcgi_store"
directives were used for subrequests (e.g. ssi includes) and client closed
connection prematurely.
Non-active subrequests are finalized out of the control of the upstream
module when client closes a connection. As a result, the code to remove
unfinished temporary files in ngx_http_upstream_process_request() wasn't
executed.
Fix is to move relevant code into ngx_http_upstream_finalize_request() which
is called in all cases, either directly or via the cleanup handler.
Empty flush buffers are legitimate and may happen e.g. due to $r->flush()
calls in embedded perl. If there are no data buffered in zlib, deflate()
will return Z_BUF_ERROR (i.e. no progress possible) without adding anything
to output. Don't treat Z_BUF_ERROR as fatal and correctly send empty flush
buffer if we have no data in output at all.
See this thread for details:
http://mailman.nginx.org/pipermail/nginx/2010-November/023693.html
If header filter postponed processing of a header by returning NGX_AGAIN
and not moved u->buffer->pos, previous check incorrectly assumed there
is additional space and did another recv() with zero-size buffer. This
resulted in "upstream prematurely closed connection" error instead
of correct "upstream sent too big header" one.
Patch by Feibo Li.
the way.
It was unintentionally changed in r4272, so that it could only limit the first
location where the processing of the request has reached PREACCESS phase.
Example configuration to reproduce:
server {
proxy_redirect off;
location / {
proxy_pass http://localhost:8000;
proxy_redirect http://localhost:8000/ /;
location ~ \.php$ {
proxy_pass http://localhost:8000;
# proxy_redirect must be inherited from the level above,
# but instead it was switched off here
}
}
}
Doing a cleanup before every lookup seems to be too aggressive. It can lead to
premature removal of the nodes still usable, which increases the amount of work
under a mutex lock and therefore decreases performance.
In order to improve cleanup behavior, cleanup function call has been moved right
before the allocation of a new node.
"limit_req_zone" directive; minimum size of zone is increased.
Previously an unsigned variable was used to keep the return value of
ngx_parse_size() function, which led to an incorrect zone size if NGX_ERROR
was returned.
The new code has been taken from the "limit_conn_zone" directive.
The aio_return() must be called regardless of the error returned by
aio_error(). Not calling it resulted in various problems up to segmentation
faults (as AIO events are level-triggered and were reported again and again).
Additionally, in "aio sendfile" case r->blocked was incremented in case of
error returned from ngx_file_aio_read(), thus causing request hangs.
Support for TLSv1.1 and TLSv1.2 protocols was introduced in OpenSSL 1.0.1
(-beta1 was recently released). This change makes it possible to disable
these protocols and/or enable them without other protocols.
The problem was localized in ngx_http_proxy_rewrite_redirect_regex() handler
function which did not take into account prefix when overwriting header value.
New directives: proxy_cache_lock on/off, proxy_cache_lock_timeout. With
proxy_cache_lock set to on, only one request will be allowed to go to
upstream for a particular cache item. Others will wait for a response
to appear in cache (or cache lock released) up to proxy_cache_lock_timeout.
Waiting requests will recheck if they have cached response ready (or are
allowed to run) every 500ms.
Note: we intentionally don't intercept NGX_DECLINED possibly returned by
ngx_http_file_cache_read(). This needs more work (possibly safe, but needs
further investigation). Anyway, it's exceptional situation.
Note: probably there should be a way to disable caching of responses
if there is already one request fetching resource to cache (without waiting
at all). Two possible ways include another cache lock option ("no_cache")
or using proxy_no_cache with some supplied variable.
Note: probably there should be a way to lock updating requests as well. For
now "proxy_cache_use_stale updating" is available.
It's possible that configured limit_rate will permit more bytes per
single operation than sendfile_max_chunk. To protect disk from takeover
by a single client it is necessary to apply sendfile_max_chunk as a limit
regardless of configured limit_rate.
See here for report (in Russian):
http://mailman.nginx.org/pipermail/nginx-ru/2010-March/032806.html
If proxy_pass was used with variables and there was no URI component,
nginx always used unparsed URI. This isn't consistent with "no variables"
case, where e.g. rewrites are applied even if there is no URI component.
Fix is to use the same logic in both cases, i.e. only use unparsed URI if
it's valid and request is the main one.
This resolves issue with try_files (see ticket #70), configuration like
location / { try_files $uri /index.php; }
location /index.php { proxy_pass http://backend; }
caused nginx to use original request uri in a request to a backend.
Historically, not clearing of the r->valid_unparsed_uri on internal redirect
was a feature: it allowed to pass the same request to (another) upstream
server via error_page redirection. Since then named locations appeared
though, and it's time to start resetting r->valid_unparsed_uri on internal
redirects. Configurations still using this feature should be converted
to use named locations instead.
Patch by Lanshun Zhou.
The SCGI specification doesn't specify format of the response, and assuming
CGI specs should be used there is no reason to complain. RFC 3875
explicitly states that "A Status header field is optional, and status
200 'OK' is assumed if it is omitted".
The r->http_version is a version of client's request, and modules must
not set it unless they are really willing to downgrade protocol version
used for a response (i.e. to HTTP/0.9 if no response headers are available).
In neither case r->http_version may be upgraded.
The former code downgraded response from HTTP/1.1 to HTTP/1.0 for no reason,
causing various problems (see ticket #66). It was also possible that
HTTP/0.9 requests were upgraded to HTTP/1.0.
There have been multiple reports of cases where a real locked entry was
removed, resulting in a segmentation fault later in a worker which locked
the entry. It looks like default inactive timeout isn't enough in real
life.
For now just ignore such locked entries, and move them to the top of the
inactive queue to allow processing of other entries.
There are two possible situations which can lead to this: response was
cached with bigger proxy_buffer_size value (and nginx was restared since
then, i.e. shared memory zone content was lost), or due to the race in
the cache update code (see [1]) we've end up with fcn->body_start from
a different response stored in shared memory zone.
[1] http://mailman.nginx.org/pipermail/nginx-devel/2011-September/001287.html
The ngx_http_cache() and ngx_http_no_cache_set_slot() functions were replaced
by ngx_http_test_predicates() and ngx_http_set_predicate_slot() in 0.8.46 and
no longer used since then.
haven't been sent to a client.
The ngx_http_variable_headers() and ngx_http_variable_unknown_header() functions
did not ignore response header entries with zero "hash" field.
Thanks to Yichun Zhang (agentzh).
It was working for nginx's own 206 replies as they are seen as 200 in the
headers filter module (range filter goes later in the headers filter chain),
but not for proxied replies.
Additional parsing logic added to correctly handle RFC 3986 compliant IPv6 and
IPvFuture characters enclosed in square brackets.
The host validation was completely rewritten. The behavior for non IP literals
was changed in a more proper and safer way:
- Host part is now delimited either by the first colon or by the end of string
if there's no colon. Previously the last colon was used as delimiter which
allowed substitution of a port number in the $host variable.
(e.g. Host: 127.0.0.1:9000:80)
- Fixed stripping of the ending dot in the Host header when the host was also
followed by a port number.
(e.g. Host: nginx.com.:80)
- Fixed upper case characters detection. Previously it was broken which led to
wasting memory and CPU.
Check if received data length match Content-Length header (if present),
don't cache response if no match found. This prevents caching of corrupted
response in case of premature connection close by upstream.
Used "\x5" in 5th byte to claim presence of both audio and video. Used
previous tag size 0 in the beginning of the flv body (bytes 10 .. 13) as
required by specification (see http://www.adobe.com/devnet/f4v.html).
Patch by Piotr Sikora.
The following problems were fixed:
1. Directive fastcgi_cache affected headers sent to backends in unrelated
servers / locations (see ticket #45).
2. If-Unmodified-Since, If-Match and If-Range headers were sent to backends
if fastcgi_cache was used.
3. Cache-related headers were sent to backends if there were no fastcgi_param
directives and fastcgi_cache was used at server level.
Headers cleared with cache enabled (If-Modified-Since etc.) might be cleared
in unrelated servers/locations without proxy_cache enabled if proxy_cache was
used in some server/location.
Example config which triggered the problem:
proxy_set_header X-Test "test";
server { location /1 { proxy_cache name; proxy_pass ... } }
server { location /2 { proxy_pass ... } }
Another one:
server {
proxy_cache name;
location /1 { proxy_pass ... }
location /2 { proxy_cache off; proxy_pass ... }
}
In both cases If-Modified-Since header wasn't sent to backend in location /2.
Fix is to not modify conf->headers_source, but instead merge user-supplied
headers from conf->headers_source and default headers (either cache or not)
into separate headers_merged array.
The following config caused segmentation fault due to conf->file not
being properly set if "ssl on" was inherited from the http level:
http {
ssl on;
server {
}
}
Previously nginx used to mark backend again as live as soon as fail_timeout
passes (10s by default) since last failure. On the other hand, detecting
dead backend takes up to 60s (proxy_connect_timeout) in typical situation
"backend is down and doesn't respond to any packets". This resulted in
suboptimal behaviour in the above situation (up to 23% of requests were
directed to dead backend with default settings).
More detailed description of the problem may be found here (in Russian):
http://mailman.nginx.org/pipermail/nginx-ru/2011-August/042172.html
Fix is to only allow one request after fail_timeout passes, and
mark backend as "live" only if this request succeeds.
Note that with new code backend will not be marked "live" unless "check"
request is completed, and this may take a while in some specific workloads
(e.g. streaming). This is believed to be acceptable.
Second aio post happened when timer set by limit_rate expired while we have
aio request in flight, resulting in "second aio post" alert and socket leak.
The patch adds actual protection from aio calls with r->aio already set to
aio sendfile code in ngx_http_copy_filter(). This should fix other cases
as well, e.g. when sending buffered to disk upstream replies while still
talking to upstream.
The ngx_http_writer() is also fixed to handle the above case (though it's
mostly optimization now).
Reported by Oleksandr V. Typlyns'kyi.
For files with '?' in their names autoindex generated links with '?' not
escaped. This resulted in effectively truncated links as '?' indicates
query string start.
This is an updated version of the patch originally posted at [1]. It
introduces generic NGX_ESCAPE_URI_COMPONENT which escapes everything but
unreserved characters as per RFC 3986. This approach also renders unneeded
special colon processing (as colon is percent-encoded now), it's dropped
accordingly.
[1] http://nginx.org/pipermail/nginx-devel/2010-February/000112.html
Reported by Konstantin Leonov.
If cache was bypassed with proxy_cache_bypass, cache-controlling headers
(Cache-Control, Expires) wasn't considered and response was cached even
if it was actually non-cacheable.
Patch by John Ferlito.
Configuration with duplicate upstream blocks defined after first use, i.e.
like
server {
...
location / {
proxy_pass http://backend;
}
}
upstream backend { ... }
upstream backend { ... }
now correctly results in "duplicate upstream" error.
Additionally, upstream blocks defined after first use now handle various
server directive parameters ("weight", "max_fails", etc.). Previously
configuration like
server {
...
location / {
proxy_pass http://backend;
}
}
upstream backend {
server 127.0.0.1 max_fails=5;
}
incorrectly resulted in "invalid parameter "max_fails=5"" error.
For normal cached responses ngx_http_cache_send() sends last buffer and then
request finalized via ngx_http_finalize_request() call, i.e. everything is
ok.
But for stale responses (i.e. when upstream died, but we have something in
cache) the same ngx_http_cache_send() sends last buffer, but then in
ngx_http_upstream_finalize_request() another last buffer is send. This
causes duplicate final chunk to appear if chunked encoding is used (and
resulting problems with keepalive connections and so on).
Fix this by not sending in ngx_http_upstream_finalize_request()
another last buffer if we know response was from cache.
The special case in question leads to replies without body in
configuration like
location / { error_page 404 /zero; return 404; }
location /zero { return 204; }
while replies with empty body are expected per protocol specs.
Correct one will look like
if (status == NGX_HTTP_NO_CONTENT) {
rc = ngx_http_send_header(r);
if (rc == NGX_ERROR || r->header_only) {
return rc;
}
return ngx_http_send_special(r, NGX_HTTP_LAST);
}
though it looks like it's better to drop this special case at all.
Big POST (not fully preread) to a
location / {
return 202;
}
resulted in incorrect behaviour due to "return" code path not calling
ngx_http_discard_request_body(). The same applies to all "return" used
with 2xx/3xx codes except 201 and 204, and to all "return ... text" uses.
Fix is to add ngx_http_discard_request_body() call to ngx_http_send_response()
function where it looks appropriate. Discard body call from emtpy gif module
removed as it's now redundant.
Reported by Pyry Hakulinen, see
http://mailman.nginx.org/pipermail/nginx/2011-August/028503.html
Test case:
location / {
error_page 405 /nope;
return 405;
}
location /nope {
return 200;
}
This is expected to return 405 with empty body, but in 0.8.42+ will return
builtin 405 error page as well (though not counted in Content-Length, thus
breaking protocol).
Fix is to use status provided by rewrite script execution in case
it's less than NGX_HTTP_BAD_REQUEST even if r->error_status set. This
check is in line with one in ngx_http_script_return_code().
Note that this patch also changes behaviour for "return 302 ..." and
"rewrite ... redirect" used as error handler. E.g.
location / {
error_page 405 /redirect;
return 405;
}
location /redirect {
rewrite ^ http://example.com/;
}
will actually return redirect to "http://example.com/" instead of builtin 405
error page with meaningless Location header. This looks like correct change
and it's in line with what happens on e.g. directory redirects in error
handlers.
Replies with 201 code contain body, and we should clearly indicate it's
empty if it's empty. Before 0.8.32 chunked was explicitly disabled for
201 replies and as a result empty body was indicated by connection close
(not perfect, but worked). Since 0.8.32 chunked is enabled, and this
causes incorrect responses from dav module when HTTP/1.1 is used: with
"Transfer-Encoding: chunked" but no chunks at all.
Fix is to actually return empty body in special response handler instead
of abusing r->header_only flag.
See here for initial report:
http://mailman.nginx.org/pipermail/nginx-ru/2010-October/037535.html
This fixes crashes observed with some 3rd party balancer modules. Standard
balancer modules (round-robin and ip hash) explicitly set pc->connection
(aka u->peer.connection) to NULL and aren't affected.
and "chunked_transfer_encoding" directives, to be in line with all
directives taking a boolean argument. Both flags will ensure that
a directive takes one argument.
By default follow the old behaviour, i.e. FASTCGI_KEEP_CONN flag isn't set
in request and application is responsible for closing connection once request
is done. To keep connections alive fastcgi_keep_conn must be activated.
As long as ngx_event_pipe() has more data read from upstream than specified
in p->length it's passed to input filter even if buffer isn't yet full. This
allows to process data with known length without relying on connection close
to signal data end.
By default p->length is set to -1 in upstream module, i.e. end of data is
indicated by connection close. To set it from per-protocol handlers upstream
input_filter_init() now called in buffered mode (as well as in
unbuffered mode).
Previous use of size_t may cause wierd effects on 32bit platforms with certain
big responses transferred in unbuffered mode.
Nuke "if (size > u->length)" check as it's not usefull anyway (preread
body data isn't subject to this check) and now requires additional check
for u->length being positive.
We no longer use r->headers_out.content_length_n as a primary source of
backend's response length. Instead we parse response length to
u->headers_in.content_length_n and copy to r->headers_out.content_length_n
when needed.
Just doing another connect isn't safe as peer.get() may expect peer.tries
to be strictly positive (this is the case e.g. with round robin with multiple
upstream servers). Increment peer.tries to at least avoid cpu hog in
round robin balancer (with the patch alert will be seen instead).
This is not enough to fully address the problem though, hence TODO. We
should be able to inform balancer that the error wasn't considered fatal
and it may make sense to retry the same peer.
The ngx_chain_update_chains() needs pool to free chain links used for buffers
with non-matching tags. Providing one helps to reduce memory consumption
for long-lived requests.
There were 2 buffers allocated on each buffer chain sent through chunked
filter (one buffer for chunk size, another one for trailing CRLF, about
120 bytes in total on 32-bit platforms). This resulted in large memory
consumption with long-lived requests sending many buffer chains. Usual
example of problematic scenario is streaming though proxy with
proxy_buffering set to off.
Introduced buffers reuse reduces memory consumption in the above problematic
scenario.
See here for initial report:
http://mailman.nginx.org/pipermail/nginx/2010-April/019814.html
Read event should be blocked after reading body, else undefined behaviour
might occur on additional client activity. This fixes segmentation faults
observed with proxy_ignore_client_abort set.
"max_ranges 0" disables ranges support at all,
"max_ranges 1" allows the single range, etc.
By default number of ranges is unlimited, to be precise, 2^31-1.
then nginx disables ranges and returns just the source response.
This fix should not affect well-behaving applications but will defeat
DoS attempts exploiting malicious byte ranges.
SSL_set_SSL_CTX() doesn't touch values cached within ssl connection
structure, it only changes certificates (at least as of now, OpenSSL
1.0.0d and earlier).
As a result settings like ssl_verify_client, ssl_verify_depth,
ssl_prefer_server_ciphers are only configurable on per-socket basis while
with SNI it should be possible to specify them different for two servers
listening on the same socket.
Workaround is to explicitly re-apply settings we care about from context
to ssl connection in servername callback.
Note that SSL_clear_options() is only available in OpenSSL 0.9.8m+. I.e.
with older versions it is not possible to clear ssl_prefer_server_ciphers
option if it's set in default server for a socket.
now cache loader processes either as many files as specified by loader_files
or works no more than time specified by loader_threshold during each iteration.
loader_threshold was previously used to decrease loader_files or
to increase loader_timeout and this might eventually result in
downgrading loader_files to 1 and increasing loader_timeout to large values
causing loading cache for forever.
The following configuration causes nginx to hog cpu due to infinite loop
in ngx_http_upstream_get_peer():
upstream backend {
server 127.0.0.1:8080 down;
server 127.0.0.1:8080 down;
}
server {
...
location / {
proxy_pass http://backend;
}
}
Make sure we don't loop infinitely in ngx_http_upstream_get_peer() but stop
after resetting peer weights once.
Return 0 if we are stuck. This is guaranteed to work as peer 0 always exists,
and eventually ngx_http_upstream_get_round_robin_peer() will do the right
thing falling back to backup servers or returning NGX_BUSY.
Flush flag wasn't set in constructed buffer and this prevented any data
from being actually sent to upstream due to SSL buffering. Make sure
we always set flush in the last buffer we are going to sent.
See here for report:
http://nginx.org/pipermail/nginx-ru/2011-June/041552.html
Previously all available data was used as body, resulting in garbage after
real body e.g. in case of pipelined requests. Make sure to use only as many
bytes as request's Content-Length specifies.
enabled in any server. The previous r1033 does not help when unused zone
becomes used after reconfiguration, so it is backed out.
The initial thought was to make SSL modules independed from SSL implementation
and to keep OpenSSL code dependance as much as in separate files.
