The casts are unnecessary, since memcmp(3)'s arguments are 'void *'.
It might have been necessary in the times of K&R, where 'void *' didn't
exist. Nowadays, it's unnecessary, and _very_ unsafe, since casts can
hide all classes of bugs by silencing most compiler warnings.
The changes from nxt_memcmp() to memcmp(3) were scripted:
$ find src/ -type f \
| grep '\.[ch]$' \
| xargs sed -i 's/nxt_memcmp/memcmp/'
Reviewed-by: Andrew Clayton <a.clayton@nginx.com>
Signed-off-by: Alejandro Colomar <alx@nginx.com>
As was pointed out by the cppcheck[0] static code analysis utility we
can mark numerous function parameters as 'const'. This acts as a hint to
the compiler about our intentions and the compiler will tell us when we
deviate from them.
[0]: https://cppcheck.sourceforge.io/
We had a mix of styles for declaring function-like macros:
Style A:
#define \
foo() \
do { \
... \
} while (0)
Style B:
#define foo() \
do { \
... \
} while (0)
We had a similar number of occurences of each style:
$ grep -rnI '^\w*(.*\\' | wc -l
244
$ grep -rn 'define.*(.*)' | wc -l
239
(Those regexes aren't perfect, but a very decent approximation.)
Real examples:
$ find src -type f | xargs sed -n '/^nxt_double_is_zero/,/^$/p'
nxt_double_is_zero(f) \
(fabs(f) <= FLT_EPSILON)
$ find src -type f | xargs sed -n '/define nxt_http_field_set/,/^$/p'
#define nxt_http_field_set(_field, _name, _value) \
do { \
(_field)->name_length = nxt_length(_name); \
(_field)->value_length = nxt_length(_value); \
(_field)->name = (u_char *) _name; \
(_field)->value = (u_char *) _value; \
} while (0)
I'd like to standardize on a single style for them, and IMO,
having the identifier in the same line as #define is a better
option for the following reasons:
- Programmers are used to `#define foo() ...` (readability).
- One less line of code.
- The program for finding them is really simple (see below).
function grep_ngx_func()
{
if (($# != 1)); then
>&2 echo "Usage: ${FUNCNAME[0]} <func>";
return 1;
fi;
find src -type f \
| grep '\.[ch]$' \
| xargs grep -l "$1" \
| sort \
| xargs pcregrep -Mn "(?s)^\$[\w\s*]+?^$1\(.*?^}";
find src -type f \
| grep '\.[ch]$' \
| xargs grep -l "$1" \
| sort \
| xargs pcregrep -Mn "(?s)define $1\(.*?^$" \
| sed -E '1s/^[^:]+:[0-9]+:/&\n\n/';
}
$ grep_ngx_func
Usage: grep_ngx_func <func>
$ grep_ngx_func nxt_http_field_set
src/nxt_http.h:98:
#define nxt_http_field_set(_field, _name, _value) \
do { \
(_field)->name_length = nxt_length(_name); \
(_field)->value_length = nxt_length(_value); \
(_field)->name = (u_char *) _name; \
(_field)->value = (u_char *) _value; \
} while (0)
$ grep_ngx_func nxt_sprintf
src/nxt_sprintf.c:56:
u_char * nxt_cdecl
nxt_sprintf(u_char *buf, u_char *end, const char *fmt, ...)
{
u_char *p;
va_list args;
va_start(args, fmt);
p = nxt_vsprintf(buf, end, fmt, args);
va_end(args);
return p;
}
................
Scripted change:
................
$ find src -type f \
| grep '\.[ch]$' \
| xargs sed -i '/define *\\$/{N;s/ *\\\n/ /;s/ //}'
Previously, all requests that contained in header field names characters other
than alphanumeric, or "-", or "_" were rejected with a 400 "Bad Request" error
response.
Now, the parser allows the same set of characters as specified in RFC 7230,
including: "!", "#", "$", "%", "&", "'", "*", "+", ".", "^", "`", "|", and "~".
Header field names that contain only these characters are considered valid.
Also, there's a new option introduced: "discard_unsafe_fields". It accepts
boolean value and it is set to "true" by default.
When this option is "true", all header field names that contain characters
in valid range, but other than alphanumeric or "-" are skipped during parsing.
When the option is "false", these header fields aren't skipped.
Requests with non-valid characters in header field names according to
RFC 7230 are rejected regardless of "discard_unsafe_fields" setting.
This closes#422 issue on GitHub.
This is required due to lack of a graceful shutdown: there is a small gap
between the runtime's memory pool release and router process's exit. Thus, a
worker thread may start processing a request between these two operations,
which may result in an http fields hash access and subsequent crash.
To simplify issue reproduction, it makes sense to add a 2 sec sleep before
exit() in nxt_runtime_exit().
This field was intended for MIME type lookup by file extension when serving
static files, but this use case is too narrow; only a fraction of requests
targets static content, and the URI presumably isn't rewritten. Moreover,
current implementation uses the entire filename for MIME type lookup if the
file has no extension.
Instead of extracting filenames and extensions when parsing requests, it's
easier to obtain them right before serving static content; this behavior is
already implemented. Thus, we can drop excessive logic from parser.
Earlier, the paths were normalized only if there was a "/" at the end, which
is wrong according to section 5.2.4 of RFC 3986 and hypothetically may allow
to the directory above the document root.
In theory, all space characters in request target must be encoded; however,
some clients may violate the specification. For the sake of interoperability,
Unit supports unencoded space characters.
Previously, if there was a space character before the extension or arguments
parts, those parts weren't recognized. Also, quoted symbols and complex
target weren't detected after a space character.
Allowing characters up to 0xFF doesn't conflict with RFC 7230.
Particularly, this make it possible to pass unencoded UTF-8 data
through HTTP headers, which can be useful.
The level hash uses the NULL value as the indicator of a free entry in a bucket.
So, inserting a NULL value breaks the hash and can lead to a bucket overflow.
In case of the collision counter, the value wasn't initialized, since it's not
needed for the purpose of checking collisions. As a result, it might contain
any garbage from the stack and in some rare cases the value was NULL.
Now the value is initilized.
