Previously, ngx_http_map_uri_to_path() errors were not checked in
ngx_http_upstream_store(). Moreover, in case of errors temporary
files were not deleted, as u->store was set to 0, preventing cleanup
code in ngx_http_upstream_finalize_request() from removing them. With
this patch, u->store is set to 0 only if there were no errors.
Reported by Feng Gu.
This ensures that debug logging and the $uri variable (if used in
400 Bad Request processing) will not try to access uninitialized
memory.
Found by Sergey Bobrov.
Split SPDY header with multiple, NULL-separated values:
cookie: foo\0bar
into two separate HTTP headers with the same name:
cookie: foo
cookie: bar
Even though the logic for this behavior already existed
in the source code, it doesn't look that it ever worked
and SPDY streams with such headers were simply rejected.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
SSL_SESSION struct is internal part of the OpenSSL library and it's fields
should be accessed via API (when exposed), not directly.
The unfortunate side-effect of this change is that we're losing reference
count that used to be printed at the debug log level, but this seems to be
an acceptable trade-off.
Almost fixes build with -DOPENSSL_NO_SSL_INTERN.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
Previously, nginx closed client connection in cases when a response body
from upstream was needed to be cached or stored but shouldn't be sent to
the client. While this is normal for HTTP, it is unacceptable for SPDY.
Fix is to use instead the p->downstream_error flag to prevent nginx from
sending anything downstream. To make this work, the event pipe code was
modified to properly cache empty responses with the flag set.
The ngx_http_upstream_dummy_handler() must be set regardless of
the read event state. This prevents possible additional call of
ngx_http_upstream_send_request_handler().
Previously, last_modified_time was tested against -1 to check if the
not modified filter should be skipped. Notably, this prevented nginx
from additional If-Modified-Since (et al.) checks on proxied responses.
Such behaviour is suboptimal in some cases though, as checks are always
skipped on responses from a cache with ETag only (without Last-Modified),
resulting in If-None-Match being ignored in such cases. Additionally,
it was not possible to return 412 from the If-Unmodified-Since if last
modification time was not known for some reason.
This change introduces explicit r->disable_not_modified flag instead,
which is set by ngx_http_upstream_process_headers().
Previous code in ngx_http_upstream_send_response() used last modified time
from r->headers_out.last_modified_time after the header filter chain was
already called. At this point, last_modified_time may be already cleared,
e.g., with SSI, resulting in incorrect last modified time stored in a
cache file. Fix is to introduce u->headers_in.last_modified_time instead.
Clearing of the r->headers_out.last_modified_time field if a response
isn't cacheable in ngx_http_upstream_send_response() was introduced
in 3b6afa999c2f, the commit to enable not modified filter for cacheable
responses. It doesn't make sense though, as at this point header was
already sent, and not modified filter was already executed. Therefore,
the line was removed to simplify code.
log->filter ("if" parameter) was uninitialized when the default value
was being used, which would lead to a crash (SIGSEGV) when access_log
directive wasn't specified in the configuration.
Zero-fill the whole structure instead of zeroing fields one-by-one
in order to prevent similar issues in the future.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
Since the type cast has precedence higher than the bit shift operator,
all values were truncated to 8 bits.
These macros are used to construct header block for SYN_REPLY frame on
platforms with strict alignment requirements. As a result, any response
that contains a header with name or value longer than 255 bytes was
corrupted on such platforms.
Do not taste the last parameter against directory, as otherwise it would
result in the trailing slash being cut from the parameter value.
Notably, this prevents an internal redirect to an empty URI
if the parameter is set to the literal slash:
location / { try_files $uri /; }
In particular, properly output partial match at the end of a subrequest
response (much like we do at the end of a response), and reset/set the
last_in_chain flag as appropriate.
Reported by KAWAHARA Masashi.
If response is gzipped we can't recode response, but in case it's not
needed we still can add charset to Content-Type.
The r->ignore_content_encoding is dropped accordingly, charset with gzip_static
now properly works without any special flags.
The ngx_http_map_uri_to_path() function used clcf->regex to detect if
it's working within a location given by a regular expression and have
to replace full URI with alias (instead of a part matching the location
prefix). This is incorrect due to clcf->regex being false in implicit
locations created by if and limit_except.
Fix is to preserve relevant information in clcf->alias instead, by setting
it to NGX_MAX_SIZE_T_VALUE if an alias was specified in a regex location.
Handling of PROXY protocol for SPDY connection is currently implemented as
a SPDY state. And while nginx waiting for PROXY protocol data it continues
to process SPDY connection: initializes zlib context, sends control frames.
- Specification-friendly handling of invalid header block or special headers.
Such errors are not fatal for session and shouldn't lead to connection close;
- Avoid mix of NGX_HTTP_PARSE_INVALID_REQUEST/NGX_HTTP_PARSE_INVALID_HEADER.
The function just calls ngx_http_spdy_state_headers_skip() most of the time.
There was also an attempt of optimization to stop parsing if the client already
closed connection, but it looks strange and unfinished anyway.
Now ngx_http_spdy_state_protocol_error() is able to close stream,
so there is no need in a separate call for this.
Also fixed zero status code in logs for some cases.
The 7022564a9e0e changeset made ineffective workaround from 2464ccebdb52
to avoid NULL pointer dereference with "if". It is now restored by
moving the u->ssl_name initialization after the check.
Found by Coverity (CID 1210408).
While managing big caches it is possible that expiring old cache items
in ngx_http_file_cache_expire() will take a while. Added a check for
ngx_quit / ngx_terminate to make sure cache manager can be terminated
while in ngx_http_file_cache_expire().
The ngx_http_proxy_rewrite_cookie() function expects the value of the
"Set-Cookie" header to be null-terminated, and for headers obtained
from proxied server it is usually true.
Now the ngx_http_proxy_rewrite() function preserves the null character
while rewriting headers.
This fixes accessing memory outside of rewritten value if both the
"proxy_cookie_path" and "proxy_cookie_domain" directives are used in
the same location.
There's a race condition between closing a stream by one endpoint
and sending a WINDOW_UPDATE frame by another. So it would be better
to just skip such frames for unknown streams, like is already done
for the DATA frames.
These directives allow to switch on Server Name Indication (SNI) while
connecting to upstream servers.
By default, proxy_ssl_server_name is currently off (that is, no SNI) and
proxy_ssl_name is set to a host used in the proxy_pass directive.
The SSL_CTX_set_cipher_list() may fail if there are no valid ciphers
specified in proxy_ssl_ciphers / uwsgi_ssl_ciphers, resulting in
SSL context leak.
In theory, ngx_pool_cleanup_add() may fail too, but this case is
intentionally left out for now as it's almost impossible and proper fix
will require changes to http ssl and mail ssl code as well.
This should prevent attempts of using pointer before it was checked, since
all modern compilers are able to spot access to uninitialized variable.
No functional changes.
Previously, an empty frame object was created for an output chain that contains
only sync or flush empty buffers. But since 39d7eef2e332 every DATA frame has
the flush flag set on its last buffer, so there's no need any more in additional
flush buffers in the output queue and they can be skipped.
Note that such flush frames caused an incorrect $body_bytes_sent value.
The SPDY draft 2 specification requires that if an endpoint receives a
control frame for a type it does not recognize, it must ignore the frame.
But the 3 and 3.1 drafts don't seem to declare any behavior for such case.
Then sticking with the previous draft in this matter looks to be right.
But previously, only 8 least significant bits of the type field were
parsed while the rest of 16 bits of the field were checked against zero.
Though there are no known frame types bigger than 255, this resulted in
inconsistency in handling of such frames: they were not recognized as
valid frames at all, and the connection was closed.
If start time is within the track but end time is out of it, error
"end time is out mp4 stts samples" is generated. However it's
better to ignore the error and output the track until its end.
The ngx_cacheline_size may be too low on some platforms, resulting
in unexpected hash build problems (as no collisions are tolerated due
to low bucket_size, and max_size isn't big enough to build a hash without
collisions). These problems aren't fatal anymore but nevertheless
need to be addressed.
The flag allows to suppress "ngx_slab_alloc() failed: no memory" messages
from a slab allocator, e.g., if an LRU expiration is used by a consumer
and allocation failures aren't fatal.
The flag is now used in the SSL session cache code, and in the limit_req
module.
Despite introducing start and end crop operations existing log
messages still mostly refer only to start. Logging is improved
to match both cases.
New debug logging is added to track entry count in atoms after
cropping.
Two format type mismatches are fixed as well.
When "start" value is equal to a track duration the request
fails with "time is out mp4 stts" like it did before track
duration check was added. Now such tracks are considered
short and skipped.
The SPDY/3.1 specification requires that the server must respond with
a 400 "Bad request" error if the sum of the data frame payload lengths
does not equal the size of the Content-Length header.
This also fixes "zero size buf in output" alert, that might be triggered
if client sends a greater than zero Content-Length header and closes
stream using the FIN flag with an empty request body.
There are a few cases in ngx_http_spdy_state_read_data() related to error
handling when ngx_http_spdy_state_skip() might be called with an inconsistent
state between *pos and sc->length, that leads to violation of frame layout
parsing and resuted in corruption of spdy connection.
Based on a patch by Xiaochen Wang.
Previously, only one case was checked: if there's more data to parse
in a r->header_in buffer, but the buffer can be filled to the end by
the last parsed entry, so we also need to check that there's no more
data to inflate.
If set, it means that response body is going to be in more than one buffer,
hence only range requests with a single range should be honored.
The flag is now used by mp4 and cacheable upstream responses, thus allowing
range requests of mp4 files with start/end, as well as range processing
on a first request to a not-yet-cached files with proxy_cache.
Notably this makes it possible to play mp4 files (with proxy_cache, or with
mp4 module) on iOS devices, as byte-range support is required by Apple.
Client address specified in the PROXY protocol header is now
saved in the $proxy_protocol_addr variable and can be used in
the realip module.
This is currently not implemented for mail.
Additionally, make sure to check for errors from ngx_http_parse_header_line()
call after joining saved parts. There shouldn't be any errors, though
check may help to catch bugs like missing f->split_parts reset.
Reported by Lucas Molas.
Previously r->header_size was used to store length for a part of
value that represents an individual already parsed HTTP header,
while r->header_end pointed to the end of the whole value.
Instead of storing length of a following name or value as pointer
to a potential end address (r->header_name_end and r->header_end)
that might be overflowed, now r->lowercase_index counter is used
to store remaining length of a following unparsed field.
It also fixes incorrect $body_bytes_sent value if a request is
closed while parsing of the request header. Since r->header_size
is intended for counting header size, thus abusing it for header
parsing purpose was certainly a bad idea.
If something like "error_page 400 @name" is used in a configuration,
a request could be passed to a named location without URI set, and this
in turn might result in segmentation faults or other bad effects
as most of the code assumes URI is set.
With this change nginx will catch such configuration problems in
ngx_http_named_location() and will stop request processing if URI
is not set, returning 500.
If a request is finalized in the first call to the
ngx_http_upstream_process_upgraded() function, e.g., because upstream
server closed the connection for some reason, in the second call
the u->peer.connection pointer will be null, resulting in segmentation
fault.
Fix is to avoid second direct call, and post event instead. This ensures
that ngx_http_upstream_process_upgraded() won't be called again if
a request is finalized.
The fix removes useless stsc entry in result mp4.
If start_sample == n then current stsc entry should be skipped
and the result stsc should start with the next entry.
The reason for that is start_sample starts from 0, not 1.
Previously, upstream's status code was overwritten with
cached response's status code when STALE or REVALIDATED
response was sent to the client.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
The size of the priority field is increased by one bit in spdy/3,
and now it's a 3-bit field followed by 5 bits of unused space.
But a shift of these bits hasn't been adjusted in 39d7eef2e332
accordingly.
If "proxy_pass" is specified with variables, the resulting
hostname is looked up in the list of upstreams defined in
configuration. The search was case-sensitive, as opposed
to the case of "proxy_pass" specified without variables.
If seek position is within the last track chunk
and that chunk is standalone (stsc entry describes only
this chunk) such seek generates stsc seek error. The
problem is that chunk numbers start with 1, not with 0.
Mp4 module does not check movie and track durations when reading
file. Instead it generates errors when track metadata is shorter
than seek position. Now such tracks are skipped and movie duration
check is performed at file read stage.
Mp4 module does not allow seeks after the last key frame. Since
stss atom only contains key frames it's usually shorter than
other track atoms. That leads to stss seek error when seek
position is close to the end of file. The fix outputs empty
stss frame instead of generating error.
Backed out 05a56ebb084a, as it turns out that kernel can return connections
without any delay if syncookies are used. This basically means we can't
assume anything about connections returned with deferred accept set.
To solve original problem the 05a56ebb084a tried to solve, i.e. to don't
wait longer than needed if a connection was accepted after deferred accept
timeout, this patch changes a timeout set with setsockopt(TCP_DEFER_ACCEPT)
to 1 second, unconditionally. This is believed to be enough for speed
improvements, and doesn't imply major changes to timeouts used.
Note that before 2.6.32 connections were dropped after a timeout. Though
it is believed that 1s is still appropriate for kernels before 2.6.32,
as previously tcp_synack_retries controlled the actual timeout and 1s results
in more than 1 minute actual timeout by default.
If there is no SSI context in a given request at a given time,
the $date_local and $date_gmt variables used "%s" format, instead
of "%A, %d-%b-%Y %H:%M:%S %Z" documented as the default and used
if there is SSI module context and timefmt wasn't modified using
the "config" SSI command.
While use of these variables outside of the SSI evaluation isn't strictly
valid, previous behaviour is certainly inconsistent, hence the fix.
Read event on a client connection might have been disabled during
previous processing, and we at least need to handle events. Calling
ngx_http_upstream_process_upgraded() is a simpliest way to do it.
Notably this change is needed for select, poll and /dev/poll event
methods.
Previous version of this patch was posted here:
http://mailman.nginx.org/pipermail/nginx/2014-January/041839.html
It simplifies the code and allows easy reuse the same queue pointer to store
streams in various queues with different requirements. Future implementation
of SPDY/3.1 will take advantage of this quality.
The "length" value better corresponds with the specification and reduces
confusion about whether frame's header is included in "size" or not.
Also this change simplifies some parts of code, since in more cases the
length of frame is more useful than its actual size, especially considering
that the size of frame header is constant.
There is no need in separate "free" pointer and like it is for ngx_chain_t
the "next" pointer can be used. But after this change successfully handled
frame should not be accessed, so the frame handling cycle was improved to
store pointer to the next frame before processing.
Also worth noting that initializing "free" pointer to NULL in the original
code was surplus.
That code was based on misunderstanding of spdy specification about
configuration applicability in the SETTINGS frames. The original
interpretation was that configuration is assigned for the whole
SPDY connection, while it is only for the endpoint.
Moreover, the strange thing is that specification forbids multiple
entries in the SETTINGS frame with the same ID even if flags are
different. As a result, Chrome sends two SETTINGS frames: one with
its own configuration, and another one with configuration stored
for a server (when the FLAG_SETTINGS_PERSIST_VALUE flags were used
by the server).
To simplify implementation we refuse to use the persistent settings
feature and thereby avoid all the complexity related with its proper
support.
The "headers" is not a good term, since it is used not only to count
name/value pairs in the HEADERS block but to count SETTINGS entries too.
Moreover, one name/value pair in HEADERS can contain multiple http headers
with the same name.
No functional changes.
While processing a DATA frame, the link to related stream is stored in spdy
connection object as part of connection state. But this stream can be closed
between receiving parts of the frame.
During the processing of input some control frames can be added to the queue.
And if there were no writing streams at the moment, these control frames might
be left unsent for a long time (or even forever).
This long delay is especially critical for PING replies since a client can
consider connection as broken and then resend exactly the same request over
a new connection, which is not safe in case of non-idempotent HTTP methods.
There is no reason to allocate it from connection pool that more like just
a bug especially since ngx_http_spdy_settings_frame_handler() already uses
sc->pool to free a chain.
The frame->stream pointer should always be initialized for control frames since
the check against it can be performed in ngx_http_spdy_filter_cleanup().
Parameters of ngx_http_spdy_filter_get_shadow() are changed from size_t to off_t
since the last call of the function may get size and offset from the rest of a
file buffer. This fixes possible data loss rightfully complained by MSVC on 32
bits systems where off_t is 8 bytes long while size_t is only 4 bytes.
The other two type casts are needed just to suppress warnings about possible
data loss also complained by MSVC but false positive in these cases.
False positive warning about the "cl" variable may be uninitialized in
the ngx_http_spdy_filter_get_data_frame() call was suppressed.
It is always initialized either in the "while" cycle or in the following
"if" condition since frame_size cannot be zero.
The "delayed" flag always should be set if there are unsent frames,
but this might not be the case if ngx_http_spdy_body_filter() was
called with NULL chain.
As a result, the "send_timeout" timer could be set on a stream in
ngx_http_writer(). And if the timeout occurred before all the stream
data has been sent, then the request was finalized with the "client
timed out" error.
It was used to prevent destroying of request object when there are unsent
frames in queue for the stream. Since it was incremented for each frame
and is only 8 bits long, so it was not very hard to overflow the counter.
Now the stream->queued counter is checked instead.
This adds support so it's possible to explicitly disable SSL Session
Tickets. In order to have good Forward Secrecy support either the
session ticket key has to be reloaded by using nginx' binary upgrade
process or using an external key file and reloading the configuration.
This directive adds another possibility to have good support by
disabling session tickets altogether.
If session tickets are enabled and the process lives for a long a time,
an attacker can grab the session ticket from the process and use that to
decrypt any traffic that occured during the entire lifetime of the
process.
If a request had an empty request body (with Content-Length: 0), and there
were preread data available (e.g., due to a pipelined request in the buffer),
the "zero size buf in output" alert might be logged while proxying the
request to an upstream.
Similar alerts appeared with client_body_in_file_only if a request had an
empty request body.
Not really a strict check (as X-Accel-Expires might be ignored or
contain invalid value), but quite simple to implement and better
than what we have now.
Fallback to synchronous sendfile() now only done on 3rd EBUSY without
any progress in a row. Not falling back is believed to be better
in case of occasional EBUSY, though protection is still needed to
make sure there will be no infinite loop.
This fixes content type set in stub_status and autoindex responses
to be usable in content type checks made by filter modules, such
as charset and sub filters.
There is no need to pass FLAG_FIN as a separate argument since it can always be
detected from the last_buf flag of the last frame buffer.
No functional changes.
Processing events from upstream connection can result in sending queued frames
from other streams. In this case such streams were not added to handling queue
and properly handled.
A global per connection flag was replaced by a per stream flag that indicates
currently sending stream while all other streams can be added to handling
queue.
Conditions for skipping ineligible peers are rewritten to make adding of new
conditions simpler and be in line with the "round_robin" and "least_conn"
modules. No functional changes.
This flag in SPDY fake write events serves the same purposes as the "ready"
flag in real events, and it must be dropped if request needs to be handled.
Otherwise, it can prevent the request from finalization if ngx_http_writer()
was set, which results in a connection leak.
Found by Xiaochen Wang.
The following new directives are introduced: proxy_cache_revalidate,
fastcgi_cache_revalidate, scgi_cache_revalidate, uwsgi_cache_revalidate.
Default is off. When set to on, they enable cache revalidation using
conditional requests with If-Modified-Since for expired cache items.
As of now, no attempts are made to merge headers given in a 304 response
during cache revalidation with headers previously stored in a cache item.
Headers in a 304 response are only used to calculate new validity time
of a cache item.
We should just call post_handler() when subrequest wants to read body, like
it happens for HTTP since rev. f458156fd46a. An attempt to init request body
for subrequests results in hang if the body was not already read.
The 403 (Forbidden) should not overwrite 401 (Unauthorized) as the
latter should be returned with the WWW-Authenticate header to request
authentication by a client.
The problem could be triggered with 3rd party modules and the "deny"
directive, or with auth_basic and auth_request which returns 403
(in 1.5.4+).
Patch by Jan Marc Hoffmann.
Much like with other headers, "add_header Cache-Control $value;" no longer
results in anything added to response headers if $value evaluates to an
empty string.
In order to support key rollover, ssl_session_ticket_key can be defined
multiple times. The first key will be used to issue and resume Session
Tickets, while the rest will be used only to resume them.
ssl_session_ticket_key session_tickets/current.key;
ssl_session_ticket_key session_tickets/prev-1h.key;
ssl_session_ticket_key session_tickets/prev-2h.key;
Please note that nginx supports Session Tickets even without explicit
configuration of the keys and this feature should be only used in setups
where SSL traffic is distributed across multiple nginx servers.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
With this change all such frames will be added in front of the output queue, and
will be sent first. It prevents HOL blocking when response with higher priority
is blocked by response with lower priority in the middle of the queue because
the order of their SYN_REPLY frames cannot be changed.
Proposed by Yury Kirpichev.
If an error occurs in a SPDY connection, the c->error flag is set on every fake
request connection, and its read or write event handler is called, in order to
finalize it. But while waiting for request headers, it was a no-op since the
read event handler had been set to ngx_http_empty_handler().
If an error occurs in a SPDY connection, the c->error flag is set on every fake
request connection, and its read or write event handler is called, in order to
finalize it. But while waiting for a request body, it was a no-op since the
read event handler ngx_http_request_handler() calls r->read_event_handler that
had been set to ngx_http_block_reading().
With previous code only part of u->buffer might be emptied in case
of special responses, resulting in partial responses seen by SSI set
in case of simple protocols, or spurious errors like "upstream sent
invalid chunked response" in case of complex ones.
Location tree was always constructed using case-sensitive comparison, even
on case-insensitive systems. This resulted in incorrect operation if
uppercase letters were used in location directives. Notably, the
following config:
location /a { ... }
location /B { ... }
failed to properly map requests to "/B" into "location /B".
