This feature allows users to specify conditions to control if access log
should be recorded. The "if" option supports a string and JavaScript code.
If its value is empty, 0, false, null, or undefined, the logs will not be
recorded. And the '!' as a prefix inverses the condition.
Example 1: Only log requests that sent a session cookie.
{
"access_log": {
"if": "$cookie_session",
"path": "..."
}
}
Example 2: Do not log health check requests.
{
"access_log": {
"if": "`${uri == '/health' ? false : true}`",
"path": "..."
}
}
Example 3: Only log requests when the time is before 22:00.
{
"access_log": {
"if": "`${new Date().getHours() < 22}`",
"path": "..."
}
}
or
{
"access_log": {
"if": "!`${new Date().getHours() >= 22}`",
"path": "..."
}
}
Closes: https://github.com/nginx/unit/issues/594
On GH, @tonychuuy reported an issue when using Units 'share' action they
would get the following error in the unit log
2024/01/15 17:53:41 [error] 49#52 *103 file "/var/www/html/public/vendor/telescope/app.css" has changed while sending response to a client
This would happen when trying to serve files over a certain size and the
requested file would not be sent.
This is due to a somewhat bogus check in
nxt_http_static_buf_completion()
I say bogus because it's not clear what the check is trying to
accomplish and the error message is not entirely accurate either.
The check in question goes like
n = pread(file->fd, buf, size, offset);
return n;
...
if (n != size) {
if (n >= 0) {
/* log file changed error and finish */
/* >> Problem is here << */
}
/* log general error and finish */
}
If the number of bytes read is not what we asked for and is > -1 (i.e
not an error) then it says the file has changed, but really it only
checks if the file has _shrunk_ (we can't get back _more_ bytes than we
asked for) since it was stat'd.
This is what happens
recvfrom(22, "GET /tfile HTTP/1.1\r\nHost: local"..., 2048, 0, NULL, NULL) = 82
openat(AT_FDCWD, "/mnt/9p/tfile", O_RDONLY|O_NONBLOCK) = 23
newfstatat(23, "", {st_mode=S_IFREG|0644, st_size=149922, ...}, AT_EMPTY_PATH) = 0
We get a request from a client, open the requested file and stat(2) it to
get the file size.
We would then go into a pread/writev loop reading the file data and
sending it to the client until it's all been sent.
However what was happening in this case was this (showing a dummy file
of 149922 bytes)
pread64(23, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072, 0) = 61440
write(2, "2024/01/17 15:30:50 [error] 1849"..., 109) = 109
We wanted to read 131072 bytes but only read 61440 bytes, the above
check triggered and the file transfer was aborted and the above error
message logged.
Normally for a regular file you will only get less bytes than asked for
if the read call is interrupted by a signal or you're near the end of
file.
There is however at least another situation where this may happen, if
the file in question is being served from a network filesystem.
It turns out that was indeed the case here, the files where being served
over the 9P filesystem protocol. Unit was running in a docker container
in an Ubuntu VM under Windows/WSL2 and the files where being passed
through to the VM from Windows over 9P.
Whatever the intention of this check, it is clearly causing issues in
real world scenarios.
If it was really desired to check if the had changed since it was
opened/stat'd then it would require a different methodology and be a
patch for another day. But as it stands this current check does more
harm than good, so lets just remove it.
With it removed we now get for the above test file
recvfrom(22, "GET /tfile HTTP/1.1\r\nHost: local"..., 2048, 0, NULL, NULL) = 82
openat(AT_FDCWD, "/mnt/9p/tfile", O_RDONLY|O_NONBLOCK) = 23
newfstatat(23, "", {st_mode=S_IFREG|0644, st_size=149922, ...}, AT_EMPTY_PATH) = 0
mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f367817b000
pread64(23, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 131072, 0) = 61440
pread64(23, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 18850, 61440) = 18850
writev(22, [{iov_base="HTTP/1.1 200 OK\r\nLast-Modified: "..., iov_len=171}, {iov_base="\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=61440}, {iov_base="\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=18850}], 3) = 80461
pread64(23, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 69632, 80290) = 61440
pread64(23, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192, 141730) = 8192
close(23) = 0
writev(22, [{iov_base="\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=61440}, {iov_base="\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., iov_len=8192}], 2) = 69632
So we can see we do two pread(2)s's and a writev(2), then another two
pread(2)s and another writev(2) and all the file data has been read and
sent to the client.
Reported-by: tonychuuy <https://github.com/tonychuuy>
Link: <https://en.wikipedia.org/wiki/9P_(protocol)>
Fixes: 08a8d1510 ("Basic support for serving static files.")
Closes: https://github.com/nginx/unit/issues/1064
Reviewed-by: Zhidao Hong <z.hong@f5.com>
Reviewed-by: Andrei Zeliankou <zelenkov@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This is to improve error messages for rewrite configuration.
Take the configuration as an example:
{
"rewrite": "`${a + "
}
Previously, when applying it the user would see this error message:
failed to apply previous configuration
After this change, the user will see this improved error message:
the previous configuration is invalid: "SyntaxError: Unexpected end of input in default:1" in the "rewrite" value.
Coverity picked up a potential issue with the previous commit d9f5f1fb7
("Ruby: Handle response field arrays") in that a size_t could wrap
around to SIZE_MAX - 1.
This would happen if we were given an empty array of header values.
Fixes: d9f5f1fb7 ("Ruby: Handle response field arrays")
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
@xeron on GitHub reported an issue whereby with a Rails 7.1 application
they were getting the following error
2023/10/22 20:57:28 [error] 56#56 [unit] #8: Ruby: Wrong header entry 'value' from application
2023/10/22 20:57:28 [error] 56#56 [unit] #8: Ruby: Failed to run ruby script
After some back and forth debugging it turns out rack was trying to send
back a header comprised of an array of values. E.g
app = Proc.new do |env|
["200", {
"Content-Type" => "text/plain",
"X-Array-Header" => ["Item-1", "Item-2"],
}, ["Hello World\n"]]
end
run app
It seems this became a possibility in rack v3.0[0]
So along with a header value type of T_STRING we need to also allow
T_ARRAY.
If we get a T_ARRAY we need to build up the header field using the given
values.
E.g
"X-Array-Header" => ["Item-1", "", "Item-3", "Item-4"],
becomes
X-Array-Header: Item-1; ; Item-3; Item-4
[0]: <https://github.com/rack/rack/blob/main/UPGRADE-GUIDE.md?plain=1#L26>
Reported-by: Ivan Larionov <xeron.oskom@gmail.com>
Closes: <https://github.com/nginx/unit/issues/974>
Link: <https://github.com/nginx/unit/pull/998>
Tested-by: Timo Stark <t.stark@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
In nxt_php_execute() it is possible we could bail out before cleaning up
the FILE * representing the PHP script to execute.
At this point we only need to call fclose(3) on it.
We could have possibly moved the opening of this file to later in the
function, but it is probably good to bail out as early as possible if we
can't open it.
This was found by Coverity.
Fixes: bebc03c72 ("PHP: Implement better error handling.")
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This fixes some typos and grammatical errors in the comments of
src/nxt_unit.h
Link: <https://github.com/nginx/unit/pull/889>
[ Adjust summary and write commit message as this just contains the
fixes from the PR and not actual changes - Andrew ]
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
The isb instruction fits for spin loops where it allows to save cpu
power.
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
On GitHub, @RomainMou reported an issue whereby HTTP header field values
where being incorrectly reported as non-ascii by the Python .isacii()
method.
For example, using the following test application
def application(environ, start_response):
t = environ['HTTP_ASCIITEST']
t = "'" + t + "'" + " (" + str(len(t)) + ")"
if t.isascii():
t = t + " [ascii]"
else:
t = t + " [non-ascii]"
resp = t + "\n\n"
start_response("200 OK", [("Content-Type", "text/plain")])
return (bytes(resp, 'latin1'))
You would see the following
$ curl -H "ASCIITEST: $" http://localhost:8080/
'$' (1) [non-ascii]
'$' has an ASCII code of 0x24 (36).
The initial idea was to adjust the second parameter to the
PyUnicode_New() call from 255 to 127. This unfortunately had the
opposite effect.
$ curl -H "ASCIITEST: $" http://localhost:8080/
'$' (1) [ascii]
Good. However...
$ curl -H "ASCIITEST: £" http://localhost:8080/
'£' (2) [ascii]
Not good. Let's take a closer look at this.
'£' is not in basic ASCII, but is in extended ASCII with a value of 0xA3
(163). Its UTF-8 encoding is 0xC2 0xA3, hence the length of 2 bytes
above.
$ strace -s 256 -e sendto,recvfrom curl -H "ASCIITEST: £" http://localhost:8080/
sendto(5, "GET / HTTP/1.1\r\nHost: localhost:8080\r\nUser-Agent: curl/8.0.1\r\nAccept: */*\r\nASCIITEST: \302\243\r\n\r\n", 92, MSG_NOSIGNAL, NULL, 0) = 92
recvfrom(5, "HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nServer: Unit/1.30.0\r\nDate: Mon, 22 May 2023 12:44:11 GMT\r\nTransfer-Encoding: chunked\r\n\r\n12\r\n'\302\243' (2) [ascii]\n\n\r\n0\r\n\r\n", 102400, 0, NULL, NULL) = 160
'£' (2) [ascii]
So we can see curl sent it UTF-8 encoded '\302\243\' which is C octal
escaped UTF-8 for 0xC2 0xA3, and we got the same back. But it should not
be marked as ASCII.
When doing PyUnicode_New(size, 127) it sets the buffer as ASCII. So we
need to use another function and that function would appear to be
PyUnicode_DecodeCharmap()
Which creates an Unicode object with the correct ascii/non-ascii
properties based on the character encoding.
With this function we now get
$ curl -H "ASCIITEST: $" http://localhost:8080/
'$' (1) [ascii]
$ curl -H "ASCIITEST: £" http://localhost:8080/
'£' (2) [non-ascii]
and for good measure
$ curl -H "ASCIITEST: $ £" http://localhost:8080/
'$ £' (4) [non-ascii]
$ curl -H "ASCIITEST: $" -H "ASCIITEST: £" http://localhost:8080/
'$, £' (5) [non-ascii]
PyUnicode_DecodeCharmap() does require having the full string upfront so
we need to build up the potentially comma separated header field values
string before invoking this function.
I did not want to touch the Python 2.7 code (which may or may not even
be affected by this) so kept these changes completely isolated from
that, hence a slight duplication with the for () loop.
Python 2.7 was sunset on January 1st 2020[0], so this code will
hopefully just disappear soon anyway.
I also purposefully didn't touch other code that may well have similar
issues (such as the HTTP header field names) if we ever get issue
reports about them, we'll deal with them then.
[0]: <https://www.python.org/doc/sunset-python-2/>
Link: <https://docs.python.org/3/c-api/unicode.html>
Closes: <https://github.com/nginx/unit/issues/868>
Reported-by: RomainMou <https://github.com/RomainMou>
Tested-by: RomainMou <https://github.com/RomainMou>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This is a preparatory patch for fixing an issue with the encoding of
http header field values.
This patch simply moves the nxt_unit_sptr_get() to the top of the
function where we will need it in the next commit.
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This was inadvertently removed in 76086d6d ("Wasm: Allow to set the HTTP
response status.")
Fixes: 76086d6d ("Wasm: Allow to set the HTTP response status.")
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
On Github, @rlandgrebe reported an issue when trying to rewrite URLs
that contained query strings.
With the PHP language module we were in fact segfaulting (SIGSEGV) in
libphp
[93960.462952] unitd[20940]: segfault at 7f307cef6476 ip 00007f2f81a94577 sp 00007fff28a777d0 error 4 in libphp-8.2.so[7f2f818df000+2fd000] likely on CPU 0 (core 0, socket 0)
#0 0x00007f2abd494577 in php_default_treat_data (arg=1, str=0x0,
destArray=<optimized out>)
at /usr/src/debug/php-8.2.10-1.fc38.x86_64/main/php_variables.c:488
488 if (c_var && *c_var) {
(gdb) p c_var
$1 = 0x7f2bb8880676 <error: Cannot access memory at address 0x7f2bb8880676>
This was when trying to get the query string which somehow is pointing
off into the woods.
This gdb debug session when doing rewrite basically shows the core of
the issue
(gdb) x /64bs req->fields
...
0x7f7eaaaa8090: "GET"
0x7f7eaaaa8094: "HTTP/1.1"
0x7f7eaaaa809d: "::1"
0x7f7eaaaa80a1: "::1"
0x7f7eaaaa80a5: "8080"
0x7f7eaaaa80aa: "localhost"
0x7f7eaaaa80b4: "/test?q=a"
0x7f7eaaaa80be: "/test"
...
(gdb) p target_pos
$4 = (void *) 0x7f7eaaaa80b4
(gdb) p query_pos
$6 = (void *) 0x7f7eaaaa6af6
(gdb) p r->args->start
$8 = (u_char *) 0x7f7ea4002b02 "q=a HTTP/1.1\r\nHost: localhost:8080\r\nUser-Agent: curl/8.0.1\r\nAccept: */*\r\n\r\n"
(gdb) p r->target.start
$9 = (u_char *) 0x7f7ea40040c0 "/test?q=a"
That last address, 0x7f7ea40040c0, looks out of wack, it should be
smaller than r->args->start.
That results in a calculation in nxt_router_prepare_msg()
if (r->args->start != NULL) {
query_pos = nxt_pointer_to(target_pos,
r->args->start - r->target.start);
nxt_unit_sptr_set(&req->query, query_pos);
} else {
that goes negative that then is stored in req->query.offset which is a
uint32_t and so wraps backwards from UINT_MAX to give us an offset of a
little under 4GiB, hence the above invalid memory access.
All this happens due to in nxt_http_rewrite() if we have a URL with a
query string, we create a new memory allocation to store the transformed
URL and query string.
We set r->target to point to this new allocation, but we also need to
point r->args->start to the start of the query string in this new
allocation.
Reported-by: René Landgrebe <https://github.com/rlandgrebe>
Tested-by: René Landgrebe <https://github.com/rlandgrebe>
Tested-by: Liam Crilly <liam.crilly@nginx.com>
Fixes: 14d6d97b ("HTTP: added basic URI rewrite.")
Closes: <https://github.com/nginx/unit/issues/964>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
The default configuration previously contained just a listeners and
applications object. Since routes is now a principle configuration object,
and a recommended way of configurating Unit, it is now included in the
default configuration.
This change benefits new users because it explicitly introduces the three
principle configuration objects which leads more intuitively to the
documentation. Experienced users may choose to ignore or delete routes.
routes is defined as an array instead of an object because this change
is designed to assist new users, where the simpler form of routes is
easier to understand.
When trying to upload files to the luw-upload-reflector demo[0] above a
certain size that would mean Unit would need to make more than two calls
to the request_handler function in the Wasm module we would get the
following error from wasmtime and the upload would stall on the third
call to the request_handler
WASMTIME ERROR: failed to call function [->wasm_request_handler]
error while executing at wasm backtrace:
0: 0x5ce2 - <unknown>!memcpy
1: 0x7df - luw_req_buf_append
at /home/andrew/src/unit-wasm/src/c/libunit-wasm.c:308:14
2: 0x3a1 - luw_request_handler
at /home/andrew/src/unit-wasm/examples/c/luw-upload-reflector.c:110:3
Caused by:
wasm trap: out of bounds memory access
This was due to ->content_off (the offset of where the actual body
content starts in the request structure/memory) being some overly large
value.
This was largely down to me being an idiot!
Before calling the loop that makes the calls to the request_handler we
would calculate the new offset, which is now just the size of the
request structure as we don't re-send all the HTTP meta data and headers
etc. However because this value is in the request structure which is in
the shared memory and we use this same memory for requests and
responses, when we make a response we overwrite this request structure
with the response structure, so our ->content_off is now some wacked out
value when we make the next call to the request_handler.
To fix this we just need to reset ->content_off each time round the
loop.
There's also no point in setting ->nfields to 0, it has the same issue
as above, but doesn't get re-used by the Wasm module anyway.
[0]: <https://github.com/nginx/unit-wasm/blob/main/examples/c/luw-upload-reflector.c>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This commit enables WebAssembly modules to set the HTTP response status
to something other than the previously hard coded '200 OK'.
To do this they can make a call to nxt_wasm_set_resp_status() providing
the required status code.
If this function isn't called the status code defaults to '200 OK'. The
WebAssembly module can also return -1 from the request_handler function
as a short cut to signal a '500 Internal Server Error'.
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
As reported by @andypost on GitHub, if you try to build Unit on a system
that uses musl libc (such as Alpine Linux) with clang then you get the
following
clang -c -pipe -fPIC -fvisibility=hidden -O -W -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -fstrict-aliasing -Wstrict-overflow=5 -Wmissing-prototypes -Werror -g -I src -I build/include \
\
\
-o build/src/nxt_socketpair.o \
-MMD -MF build/src/nxt_socketpair.dep -MT build/src/nxt_socketpair.o \
src/nxt_socketpair.c
In file included from src/nxt_socketpair.c:8:
src/nxt_socket_msg.h:138:17: error: comparison of integers of different signs: 'unsigned long' and 'long' [-Werror,-Wsign-compare]
cmsg = CMSG_NXTHDR(&msg, cmsg))
^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/sys/socket.h:358:44: note: expanded from macro 'CMSG_NXTHDR'
__CMSG_LEN(cmsg) + sizeof(struct cmsghdr) >= __MHDR_END(mhdr) - (unsigned char *)(cmsg) \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from src/nxt_socketpair.c:8:
src/nxt_socket_msg.h:177:17: error: comparison of integers of different signs: 'unsigned long' and 'long' [-Werror,-Wsign-compare]
cmsg = CMSG_NXTHDR(&msg, cmsg))
^~~~~~~~~~~~~~~~~~~~~~~
/usr/include/sys/socket.h:358:44: note: expanded from macro 'CMSG_NXTHDR'
__CMSG_LEN(cmsg) + sizeof(struct cmsghdr) >= __MHDR_END(mhdr) - (unsigned char *)(cmsg) \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 errors generated.
make: *** [build/Makefile:261: build/src/nxt_socketpair.o] Error 1
GCC works fine, it seems to have some smarts so that it doesn't give
warnings on system header files.
This seems to be a long standing issue with musl libc (bad casting in
the CMSG_NXTHDR macro) and the workaround employed by several projects
is to disable the -Wsign-compare clang warning for the code in question.
So, that's what we do. We wrap the CMSG_NXTHDR macro in a function, so
we can use the pre-processor in it to selectively disable the warning.
Link: <https://github.com/dotnet/runtime/issues/16438>
Link: <https://git.openembedded.org/meta-openembedded/tree/meta-oe/recipes-devtools/breakpad/breakpad/0001-Turn-off-sign-compare-for-musl-libc.patch>
Link: <https://github.com/dotnet/corefx/blob/57ff88bb75a0/src/Native/Unix/System.Native/pal_networking.c#L811-L829>
Link: <https://patchwork.yoctoproject.org/project/oe/patch/20220407191438.3696227-1-stefan@datenfreihafen.org/>
Closes: <https://github.com/nginx/unit/issues/936>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
Due to the sandboxed nature of WebAssembly, by default WASM modules
don't have any access to the underlying filesystem.
There is however a capabilities based mechanism[0] for allowing such
access.
This adds a config option to the 'wasm' application type;
'access.filesystem' which takes an array of directory paths that are
then made available to the WASM module. This access works recursively,
i.e everything under a specific path is allowed access to.
Example config might look like
"access" {
"filesystem": [
"/tmp",
"/var/tmp"
]
}
The actual mechanism used allows directories to be mapped differently in
the guest. But at the moment we don't support that and just map say /tmp
to /tmp. This can be revisited if it's something users clamour for.
Network sockets are another resource that may be controlled in this
manner, for example there is a wasi_config_preopen_socket() function,
however this requires the runtime to open the network socket then
effectively pass this through to the guest.
This is something that can be revisited in the future if users desire
it.
[0]:
<https://github.com/bytecodealliance/wasmtime/blob/main/docs/WASI-capabilities.md>
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This exposes various WebAssembly language module specific options.
The application type is "wasm".
There is a "module" option that is required, this specifies the full
path to the WebAssembly module to be run. This module should be in
binary format, i.e a .wasm file.
There are also currently eight function handlers that can be specified.
Three of them are _required_
1) request_handler
The main driving function. This may be called multiple times for a
single HTTP request if the request is larger than the shared memory.
2) malloc_handler
Used to allocate a chunk of memory at language module startup. This
memory is allocated from the WASM modules address space and is what is
sued for communicating between the WASM module (the guest) and Unit (the
host).
3) free_handler
Used to free the memory from above at language module shutdown.
Then there are the following five _optional_ handlers
1) module_init_handler
If set, called at language module startup.
2) module_end_handler
If set, called at language module shutdown.
3) request_init_handler
If set, called at the start of request. Called only once per HTTP
request.
4) request_end_handler
If set, called once all of a request has been sent to the WASM module.
5) response_end_handler
If set, called at the end of a request, once the WASM module has sent
all its headers and data.
Example config
"applications": {
"luw-echo-request": {
"type": "wasm",
"module": "/path/to/unit-wasm/examples/c/luw-echo-request.wasm",
"request_handler": "luw_request_handler",
"malloc_handler": "luw_malloc_handler",
"free_handler": "luw_free_handler",
"module_init_handler": "luw_module_init_handler",
"module_end_handler": "luw_module_end_handler",
}
}
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This adds the core of runtime WebAssembly[0] support. Future commits
will enable this in the Unit core and expose the configuration.
This introduces a new src/wasm directory for storing this source.
We are initially using Wasmtime[0] as the WebAssembly runtime, however
this has been designed with the ability to use different runtimes in
mind.
src/wasm/nxt_wasm.[ch] is the main interface to Unit.
src/wasm/nxt_rt_wasmtime.c is the Wasmtime runtime support. This is
nicely insulated from any knowledge of internal Unit workings.
Wasmtime is what loads and runs the Wasm modules.
The Wasm modules can export functions Wasmtime can call and Wasmtime can
export functions that the module can call.
We make use of both. The terminology used is that function exports are
what the Wasm module exports and function imports are what the Wasm
runtime exports to the module.
We currently have four function imports (functions exported by the
runtime to be called by the Wasm module).
1) nxt_wasm_get_init_mem_size
This allows Wasm modules to get the size of the initially allocated
shared memory. This is the size allocated at Unit startup and what the
Wasm modules can assume they have access to (in reality this shared
memory will likely be larger).
The amount of memory allocated at startup is NXT_WASM_MEM_SIZE which as
of this commit is 32MiB.
We do actually allocate NXT_WASM_MEM_SIZE + NXT_WASM_PAGE_SIZE at
startup which is an extra 64KiB (the smallest allocation unit), this is
to allow room for the response structure and so module developers can
just assume they have the full 32MiB for their actual response.
2) nxt_wasm_send_headers
This allows WASM modules to send their headers.
3) nxt_wasm_send_response
This allows WASM modules to send their response.
4) nxt_wasm_response_end
This allows WASM modules to inform Unit they have finished sending their
response. This calls nxt_unit_request_done()
Then there are currently up to eight functions that a module can export.
Three of which are required. These function can be named anything. I'll
use the Unit configuration names to refer to them
1) request_handler
The main driving function. This may be called multiple times for a
single HTTP request if the request is larger than the shared memory.
2) malloc_handler
Used to allocate a chunk of memory at language module startup. This
memory is allocated from the WASM modules address space and is what is
sued for communicating between the WASM module (the guest) and Unit (the
host).
3) free_handler
Used to free the memory from above at language module shutdown.
Then there are the following optional handlers
1) module_init_handler
If set, called at language module startup.
2) module_end_handler
If set, called at language module shutdown.
3) request_init_handler
If set, called at the start of request. Called only once per HTTP
request.
4) request_end_handler
If set, called once all of a request has been sent to the WASM module.
5) response_end_handler
If set, called at the end of a request, once the WASM module has sent
all its headers and data.
32bits
We currently support 32bit WASM modules, I.e wasm32-wasi. Newer version
of clang, 13+[2], do seem to have support for wasm64 as a target (which
uses a LP64 model). However it's not entirely clear if the WASI SDK
fully supports[3] this and by extension WASI libc/wasi-sysroot.
64bit support is something than can be explored more thoroughly in the
future.
As such in structures that are used to communicate between the host and
guest we use 32bit ints. Even when a single byte might be enough. This
is to avoid issues with structure layout differences between a 64bit
host and 32bit guest (I.e WASM module) and the need for various bits of
structure padding depending on host architecture. Instead everything is
4-byte aligned.
[0]: <https://webassembly.org/>
[1]: <https://wasmtime.dev/>
[2]: <https://reviews.llvm.org/rG670944fb20b226fc22fa993ab521125f9adbd30a>
[3]: <https://github.com/WebAssembly/wasi-sdk/issues/185>
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This is required to actually _build_ the Wasm language module.
The nxt_wasm_app_conf_t structure consists of the modules name, e.g
wasm, then the three required function handlers followed by the five
optional function handlers.
See the next commit for details of these function handlers.
We also need to include the u.wasm union entry that provides access to
the above structure.
The bulk of the configuration infrastructure will be added in a
subsequent commit.
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This is the first patch in adding WebAssembly language module support.
This just adds a new NXT_APP_WASM type, required by subsequent commits.
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This makes it much more clear what's what.
This is in preparation for adding WebAssembly language module support.
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This commit is to reimplement the variables with an unknown field
such as $header_{name} to make the parsing more generic,
it's a preparation for supporting response header variables.
When a variable is accessed in the Unit configuration, the value is cached.
This was useful prior to the URI rewrite feature, but now that the URI (more
precisely, the request target) can be rewritten, the contents of the variable
$uri (which contains the path part of the request target, and is decoded)
should not be cached anymore, or at least the cached value should be invalidated
after a URI rewrite.
Example:
{
"rewrite": "/prefix$uri",
"share": "$uri"
}
For a request line like GET /foo?bar=baz HTTP/1.1\r\n, the expected file
served in the response would be /prefix/foo, but due to the caching issue,
Unit currently serves /foo.
Lifespan state is a special dict in asgi lifespan scope, which allow
applications to persist data from the lifespan cycle to request/response
handling. The scope["state"] namespace provides a place to store these
sorts of things. The server will ensure that a shallow copy of the
namespace is passed into each subsequent request/response call into the
application.
Some frameworks are already taking advantage of this feature, for
example, starlette, and without this feature they wouldn't work
properly.
Signed-off-by: synodriver <diguohuangjiajinweijun@gmail.com>
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
[ Minor code tweaks to avoid lines > 80 chars, static a function and
re-work the PyMemberDef structure initialisation for Python <3.7
and -Wwrite-strings compatibility - Andrew ]
Tested-by: <https://github.com/synodriver>
Tested-by: <https://github.com/hawiliali>
Closes: <https://github.com/nginx/unit/issues/864>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
If we don't update the pointer before copying the request body, then we
get the behavior shown below. After this patch, "foo\n" is rightly
appended at the end of the response body.
Request:
"GET / HTTP/1.1\r\nHost: _\nContent-Length: 4\n\nfoo\n"
Response body:
"""
Hello world!
foo
est data:
Method: GET
Protocol: HTTP/1.1
Remote addr: 127.0.0.1
Local addr: 127.0.0.1
Target: /
Path: /
Fields:
Host: _
Content-Length: 4
Body:
"""
Fixes: 1bb22d1e92 ("Unit application library.")
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>
We renamed the options recently, with the intention of keeping the old
names as supported but deprecated for some time, before removal. This
was done with the configure script options, but in the unitd binary, we
accidentally removed the old names, causing some unintended breakage.
Keep support for the old names, albeit with a deprecation message to
stderr, for some time, until we decide to remove them.
Fixes: 5a37171f73 ("Added default values for pathnames.")
Closes: <https://github.com/nginx/unit/issues/876>
Reported-by: El RIDO <elrido@gmx.net>
Acked-by: Liam Crilly <liam@nginx.com>
Acked-by: Artem Konev <a.konev@f5.com>
Acked-by: Timo Stark <t.stark@nginx.com>
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Cc: Andrei Zeliankou <zelenkov@nginx.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>
