For each request, the worker calls the php_execute_script function
from libphp that changes to the script directory before doing its
work and then restores the process directory before returning. The
chdir(2) calls it performs are unnecessary in Unit design. In simple
benchmarks, profiling shows that the chdir syscall code path (syscall,
FS walk, etc.) is where the CPU spends most of its time.
PHP SAPI semantics requires the script to be run from the script
directory. In Unit's PHP implementation, we have two use cases:
- script
- arbitrary path
The "script" configuration doesn't have much need for a working
directory change: it can be changed once at module initialization.
The module needs to chdir again only if the user's PHP script also
calls chdir to switch to another directory during execution.
If "script" is not used in Unit configuration, we must ensure the
script is run from its directory (thus calling chdir before exec),
but there's no need to restore the working directory later.
Our implementation disables mandatory chdir calls with the SAPI
option SAPI_OPTION_NO_CHDIR, instead calling chdir only when needed.
To detect the user's calls to chdir, a simple "unit" extension is
added that hooks the built-in chdir() PHP call.
A check for the ".php" extension is added to prevent execution of files
with arbitrary extensions in cases where "index" and "script" options
aren't used.
There's no reason to parse "http_status_line"; the PHP interpreter already
does this. If the line contains a valid status code, it's assigned to
"http_response_code".
This also fixes invalid status line handling, where the nxt_int_parse()
function returned -1; it was cast to unsigned, yielding response code 65535.
According to CGI/1.1 RFC 3875:
The server MUST set this variable; if the Script-URI does not include a
query component, the QUERY_STRING MUST be defined as an empty string ("").
Python's PEP 333(3) allows omitting it in WSGI interface; PHP docs force no
requirements; PSGI and Rack specifications require it even if empty.
When nginx proxies requests over FastCGI, it always provides QUERY_STRING.
and some PHP apps have been observed to fail if it is missing (see issue
#201 on GitHub).
A drawback of this change (besides a small overhead) is that there will be
no easy way to tell a missing query string from an empty one (i.e. requests
with or without the "?" character); yet, it's negligible compared to the
possible benefits of wider application compatibility.
This closes#226 issue on GitHub.
Previously, the nxt_router_prepare_msg() function expected server host among
other headers unmodified. It's not true anymore since normalization of the
Host header has been introduced in 77aad2c142a0.
The nxt_unit_split_host() function was removed. It didn't work correctly with
IPv6 literals. Anyway, after 77aad2c142a0 the port splitting is done in router
while Host header processing.
Since PHP 7, a zend_signal_startup() call is required if the interpreter
was built with ZEND_SIGNALS defined; such a call was added in 3fd76e4ce70a.
However, the zend_signal_startup() export is missing from the PHP library;
as the result, dlopen() fails with the 'Undefined symbol "zend_signal_startup"'
error while loading the PHP module.
Meanwhile, if PHP is built without ZTS, the zend_signal_startup() call can
be omitted; otherwise, the missing call causes segmentation fault.
The PHP fix already was committed to upstream, but we still have to deal
with numerous unpatched versions remaining at large.
See the related PHP bug: https://bugs.php.net/bug.php?id=71041
The implementation of module was based on the assumption that PHP reads request
body and headers in the particular order. For the POST request the body goes
before headers and vice versa for all other requests.
But as it appeared later, this order is unspecified and depends on many factors,
including the particular code of PHP application. Among other factors those
can affect ordering:
- presence of "Content-Type" header;
- "variables_order" php.ini setting;
- "enable_post_data_reading" php.ini setting;
- reading php://input by application;
and this list can be incomplete.
As a temporary workaround, request body now is always put before headers and it
is gracefully skipped whenever PHP wants to get headers.
This closes#144 issue on GitHub.
The previous method changed PHP options only for the first request.
On the request completion the options were rolled back.
This closes#145 issue on GitHub.
PHP SAPI can call log handler while initializing. Particularly, that happens
if there's a problem in loading some extension specified in php.ini file.
On this stage server context is empty, so now nxt_thread_log_error() is used.
PHP SAPI tries to read body for POST request before registering
header-specific variables. For other methods, read_post_body() called by SAPI
after variables registration.
This closes#10 issue on GitHub.
Configuration and building example:
./configure
./configure python
./configure php
./configure go
make all
or
./configure
make nginext
./configure python
make python
./configure php
make php
./configure go
make go
Modules configuration options and building examples:
./configure python --module=python2 --config=python2.7-config
make python2
./configure php --module=php7 --config=php7.0-config
--lib-path=/usr/local/php7.0
make php7
./configure go --go=go1.6 --go-path=${HOME}/go1.6
make go1.6
