The functions ngx_http_merge_types() & ngx_conf_merge_path_value()
return either NGX_CONF_OK aka NULL aka ((void *)0) (probably) or
NGX_CONF_ERROR aka ((void *)-1).
They don't return an integer constant which is what NGX_OK aka (0) is.
Lets use the right thing in the function return check.
This was found with -Wzero-as-null-pointer-constant which was enabled
for C in GCC 15 (not enabled with Wall or Wextra... yet).
Link: <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117059>
Renaming a temporary file to an empty path ("") returns NGX_ENOPATH
with a subsequent ngx_create_full_path() to create the full path.
This function skips initial bytes as part of path separator lookup,
which causes out of bounds access on short strings.
The fix is to avoid renaming a temporary file to an obviously invalid
path, as well as explicitly forbid such syntax for literal values.
Although Coverity reports about potential type underflow, it is not
actually possible because the terminating '\0' is always included.
Notably, the run-time check is sufficient enough for Win32 as well.
Other short invalid values result either in NGX_ENOENT or NGX_EEXIST
and "MoveFile() .. failed" critical log messages, which involves a
separate error handling.
Prodded by Coverity (CID 1605485).
Status header with an empty reason-phrase, such as "Status: 404 ", is
valid per CGI specification, but looses the trailing space during parsing.
Currently, this results in "HTTP/1.1 404" HTTP status line in the response,
which violates HTTP specification due to missing trailing space.
With this change, only the status code is used from such short Status
header lines, so nginx will generate status line itself, with the space
and appropriate reason phrase if available.
Reported at:
https://mailman.nginx.org/pipermail/nginx/2023-August/EX7G4JUUHJWJE5UOAZMO5UD6OJILCYGX.html
With this change, duplicate Content-Length and Transfer-Encoding headers
are now rejected. Further, responses with invalid Content-Length or
Transfer-Encoding headers are now rejected, as well as responses with both
Content-Length and Transfer-Encoding.
FastCGI responder is expected to receive CGI/1.1 environment variables
in the parameters (see section "6.2 Responder" of the FastCGI specification).
Obviously enough, there cannot be multiple environment variables with
the same name.
Further, CGI specification (RFC 3875, section "4.1.18. Protocol-Specific
Meta-Variables") explicitly requires to combine headers: "If multiple
header fields with the same field-name are received then the server MUST
rewrite them as a single value having the same semantics".
In b87b7092cedb (nginx 1.21.1), logging level of "upstream sent invalid
header" errors was accidentally changed to "info". This change restores
the "error" level, which is a proper logging level for upstream-side
errors.
In 71edd9192f24 logging of invalid headers which were rejected with the
NGX_HTTP_PARSE_INVALID_HEADER error was restricted to just the "client
sent invalid header line" message, without any attempts to log the header
itself.
This patch returns logging of the header up to the invalid character and
the character itself. The r->header_end pointer is now properly set
in all cases to make logging possible.
The same logging is also introduced when parsing headers from upstream
servers.
After 05e42236e95b (1.19.1) responses with extra data might result in
zero size buffers being generated and "zero size buf" alerts in writer
(if f->rest happened to be 0 when processing additional stdout data).
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Fix is to
drop extra data instead, as it naturally happens in most clients.
Additionally, we now also issue a warning if the response is too
short, and make sure the fact it is truncated is propagated to the
client. The u->error flag is introduced to make it possible to
propagate the error to the client in case of unbuffered proxying.
For responses to HEAD requests there is an exception: we do allow
both responses without body and responses with body matching the
Content-Length header.
Cast to intermediate "void *" to lose compiler knowledge about the original
type and pass the warning. This is not a real fix but rather a workaround.
Found by gcc8.
The fields "uri", "location", and "url" from ngx_http_upstream_conf_t
moved to ngx_http_proxy_loc_conf_t and ngx_http_proxy_vars_t, reflect
this change in create_loc_conf comments.
Previously, only the upstream response body could be accessed with the
NGX_HTTP_SUBREQUEST_IN_MEMORY feature. Now any response body from a subrequest
can be saved in a memory buffer. It is available as a single buffer in r->out
and the buffer size is configured by the subrequest_output_buffer_size
directive.
Upstream, proxy and fastcgi code used to handle the old-style feature is
removed.
Previously, nginx failed to move buffer position when parsing an incomplete
record header, and due to this wasn't be able to continue parsing once
remaining bytes of the record header were received.
This can affect response header parsing, potentially generating spurious errors
like "upstream sent unexpected FastCGI request id high byte: 1 while reading
response header from upstream". While this is very unlikely, since usually
record headers are written in a single buffer, this still can happen in real
life, for example, if a record header will be split across two TCP packets
and the second packet will be delayed.
This does not affect non-buffered response body proxying, due to "buf->pos =
buf->last;" at the start of the ngx_http_fastcgi_non_buffered_filter()
function. Also this does not affect buffered response body proxying, as
each input buffer is only passed to the filter once.
Previously, an allocation error resulted in uninitialized memory access
when evaluating $upstream_http_ variables.
On a related note, see r->headers_out.headers cleanup work in 0cdee26605f3.
This change adds "http_429" parameter to "proxy_next_upstream" for
retrying rate-limited requests, and to "proxy_cache_use_stale" for
serving stale cached responses after being rate-limited.
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
It configures a threshold in bytes, above which client range
requests are not cached. In such a case the client's Range
header is passed directly to a proxied server.
This fixes inconsistency in what is stored in the "host" field.
Normally it would contain the "host" part of the parsed URL
(e.g., proxy_pass with variables), but for the case of an
implicit upstream specified with literal address it contained
the text representation of the socket address (that is, host
including port for IP).
Now the "host" field always contains the "host" part of the URL,
while the text representation of the socket address is stored
in the newly added "name" field.
The ngx_http_upstream_create_round_robin_peer() function was
modified accordingly in a way to be compatible with the code
that does not know about the new "name" field.
The "stream" code was similarly modified except for not adding
compatibility in ngx_stream_upstream_create_round_robin_peer().
This change is also a prerequisite for the next change.
When headers are set at the "http" level and not redefined in
a server block, we now preserve conf->headers into the "http"
section configuration to inherit it to all servers.
The same applies to conf->headers_cache, though it may not be effective
if no servers use cache at the "server" level as conf->headers_cache
is only initialized if cache is enabled on a given level.
Similar changes made in fastcgi/scgi/uwsgi to preserve conf->params
and conf->params_cache.
This parameter lets binding the proxy connection to a non-local address.
Upstream will see the connection as coming from that address.
When used with $remote_addr, upstream will accept the connection from real
client address.
Example:
proxy_bind $remote_addr transparent;
This prevents forming empty records out of such buffers. Particularly it fixes
double end-of-stream records with chunked transfer encoding, or when HTTP/2 is
used and the END_STREAM flag has been sent without data. In both cases there
is an empty buffer at the end of the request body chain with the "last_buf"
flag set.
The canonical libfcgi, as well as php implementation, tolerates such records,
while the HHVM parser is more strict and drops the connection (ticket #950).
By default, requests with non-idempotent methods (POST, LOCK, PATCH)
are no longer retried in case of errors if a request was already sent
to a backend. Previous behaviour can be restored by using
"proxy_next_upstream ... non_idempotent".
If an upstream with variables evaluated to address without a port,
then instead of a "no port in upstream" error an attempt was made
to connect() which failed with EADDRNOTAVAIL.
Resolved warnings about declarations that hide previous local declarations.
Warnings about WSASocketA() being deprecated resolved by explicit use of
WSASocketW() instead of WSASocket(). When compiling without IPv6 support,
WinSock deprecated warnings are disabled to allow use of gethostbyname().
The configuration handling code has changed to look similar to the proxy_store
directive and friends. This simplifies adding variable support in the following
patch.
No functional changes.
Currently, storing and caching mechanisms cannot work together, and a
configuration error is thrown when the proxy_store and proxy_cache
directives (as well as their friends) are configured on the same level.
But configurations like in the example below were allowed and could result
in critical errors in the error log:
proxy_store on;
location / {
proxy_cache one;
}
Only proxy_store worked in this case.
For more predictable and errorless behavior these directives now prevent
each other from being inherited from the previous level.
This changes internal API related to handling of the "store"
flag in ngx_http_upstream_conf_t. Previously, a non-null value
of "store_lengths" was enough to enable store functionality with
custom path. Now, the "store" flag is also required to be set.
No functional changes.
The proxy_store, fastcgi_store, scgi_store and uwsgi_store were inherited
incorrectly if a directive with variables was defined, and then redefined
to the "on" value, i.e. in configurations like:
proxy_store /data/www$upstream_http_x_store;
location / {
proxy_store on;
}
The proxy_pass directive and other handlers are not expected to be inherited
into nested locations, but there is a special code to inherit upstream
handlers into limit_except blocks, as well as a configuration into if{}
blocks. This caused incorrect behaviour in configurations with nested
locations and limit_except blocks, like this:
location / {
proxy_pass http://u;
location /inner/ {
# no proxy_pass here
limit_except GET {
# nothing
}
}
}
In such a configuration the limit_except block inside "location /inner/"
unexpectedly used proxy_pass defined in "location /", while it shouldn't.
Fix is to avoid inheritance of conf->upstream.upstream (and
conf->proxy_lengths) into locations which don't have noname flag.
Instead of independant inheritance of conf->upstream.upstream (proxy_pass
without variables) and conf->proxy_lengths (proxy_pass with variables)
we now test them both and inherit only if neither is set. Additionally,
SSL context is also inherited only in this case now.
Based on the patch by Alexey Radkov.
The upstream modules remove and alter a number of client headers
before sending the request to upstream. This set of headers is
smaller or even empty when cache is disabled.
It's still possible that a request in a cache-enabled location is
uncached, for example, if cache entry counter is below min_uses.
In this case it's better to alter a smaller set of headers and
pass more client headers to backend unchanged. One of the benefits
is enabling server-side byte ranges in such requests.
Once this age is reached, the cache lock is discarded and another
request can acquire the lock. Requests which failed to acquire
the lock are not allowed to cache the response.
The new directives {proxy,fastcgi,scgi,uwsgi,memcached}_next_upstream_tries
and {proxy,fastcgi,scgi,uwsgi,memcached}_next_upstream_timeout limit
the number of upstreams tried and the maximum time spent for these tries
when searching for a valid upstream.
