[PATCH 02 of 12] Win32: non-ASCII names support in "include" with wildcards

Maxim Dounin mdounin at mdounin.ru
Sun Feb 19 17:18:58 UTC 2023


Hello!

On Fri, Feb 17, 2023 at 06:53:11PM +0400, Sergey Kandaurov wrote:

> > On 13 Jan 2023, at 01:35, Maxim Dounin <mdounin at mdounin.ru> wrote:
> > 
> > # HG changeset patch
> > # User Maxim Dounin <mdounin at mdounin.ru>
> > # Date 1673548899 -10800
> > #      Thu Jan 12 21:41:39 2023 +0300
> > # Node ID d05c0adf5890aecc68ce8906ef19ca07502ed071
> > # Parent  60d845f9505fe1b97c1e04b680523b790e29fdb1
> > Win32: non-ASCII names support in "include" with wildcards.
> > 
> > Notably, ngx_open_glob() now supports opening directories with non-ASCII
> > characters, and pathnames returned by ngx_read_glob() are converted to UTF-8.
> > 
> > diff -r 60d845f9505f -r d05c0adf5890 src/os/win32/ngx_files.c
> > --- a/src/os/win32/ngx_files.c	Thu Jan 12 21:41:30 2023 +0300
> > +++ b/src/os/win32/ngx_files.c	Thu Jan 12 21:41:39 2023 +0300
> > @@ -546,14 +546,27 @@ ngx_open_glob(ngx_glob_t *gl)
> > {
> >     u_char     *p;
> >     size_t      len;
> > +    u_short    *u;
> >     ngx_err_t   err;
> > +    u_short     utf16[NGX_UTF16_BUFLEN];
> > 
> > -    gl->dir = FindFirstFile((const char *) gl->pattern, &gl->finddata);
> > +    len = NGX_UTF16_BUFLEN;
> > +    u = ngx_utf8_to_utf16(utf16, gl->pattern, &len, 0);
> > +
> > +    if (u == NULL) {
> > +        return NGX_ERROR;
> > +    }
> > +
> > +    gl->dir = FindFirstFileW(u, &gl->finddata);
> > 
> >     if (gl->dir == INVALID_HANDLE_VALUE) {
> > 
> >         err = ngx_errno;
> > 
> > +        if (u != utf16) {
> > +            ngx_free(u);
> > +        }
> > +
> >         if ((err == ERROR_FILE_NOT_FOUND || err == ERROR_PATH_NOT_FOUND)
> >              && gl->test)
> >         {
> > @@ -561,6 +574,8 @@ ngx_open_glob(ngx_glob_t *gl)
> >             return NGX_OK;
> >         }
> > 
> > +        ngx_set_errno(err);
> > +
> >         return NGX_ERROR;
> >     }
> > 
> > @@ -570,18 +585,10 @@ ngx_open_glob(ngx_glob_t *gl)
> >         }
> >     }
> > 
> > -    len = ngx_strlen(gl->finddata.cFileName);
> > -    gl->name.len = gl->last + len;
> > -
> > -    gl->name.data = ngx_alloc(gl->name.len + 1, gl->log);
> > -    if (gl->name.data == NULL) {
> > -        return NGX_ERROR;
> > +    if (u != utf16) {
> > +        ngx_free(u);
> >     }
> > 
> > -    ngx_memcpy(gl->name.data, gl->pattern, gl->last);
> > -    ngx_cpystrn(gl->name.data + gl->last, (u_char *) gl->finddata.cFileName,
> > -                len + 1);
> > -
> >     gl->ready = 1;
> > 
> >     return NGX_OK;
> > @@ -591,40 +598,25 @@ ngx_open_glob(ngx_glob_t *gl)
> > ngx_int_t
> > ngx_read_glob(ngx_glob_t *gl, ngx_str_t *name)
> > {
> > -    size_t     len;
> > -    ngx_err_t  err;
> > +    u_char     *p;
> > +    size_t      len;
> > +    ngx_err_t   err;
> > +    u_char      utf8[NGX_UTF16_BUFLEN];
> 
> Mixing UTF16-specific macro with u_char utf8[] looks suspicious.

That's just some preallocated buffer size.  If it feels better, a 
separate macro can be used instead.  This will also make it 
possible to fine-tune the buffer:

diff -r aca8812f2482 src/os/win32/ngx_files.c
--- a/src/os/win32/ngx_files.c	Sat Feb 18 12:58:54 2023 +0300
+++ b/src/os/win32/ngx_files.c	Sat Feb 18 13:05:34 2023 +0300
@@ -10,6 +10,7 @@
 
 
 #define NGX_UTF16_BUFLEN  256
+#define NGX_UTF8_BUFLEN   512
 
 static ngx_int_t ngx_win32_check_filename(u_char *name, u_short *u,
     size_t len);
@@ -601,7 +602,7 @@ ngx_read_glob(ngx_glob_t *gl, ngx_str_t 
     u_char     *p;
     size_t      len;
     ngx_err_t   err;
-    u_char      utf8[NGX_UTF16_BUFLEN];
+    u_char      utf8[NGX_UTF8_BUFLEN];
 
     if (gl->no_match) {
         return NGX_DONE;
@@ -632,7 +633,7 @@ ngx_read_glob(ngx_glob_t *gl, ngx_str_t 
 
 convert:
 
-    len = NGX_UTF16_BUFLEN;
+    len = NGX_UTF8_BUFLEN;
     p = ngx_utf16_to_utf8(utf8, gl->finddata.cFileName, &len, NULL);
 
     if (p == NULL) {


> It may have sense to replace this with dynamic allocation
> inside ngx_utf16_to_utf8(), similar to ngx_read_dir() 1st call,
> or use NGX_MAX_PATH.

Much like in other functions in this file, the idea is to avoid 
dynamic allocations in most cases by providing an easy to 
implement stack-based buffer.  The approach used in ngx_read_dir() 
is more complex since the result of the conversion needs to be 
maintained between calls (to be available via the ngx_de_name() 
macro).  For ngx_read_glob(), a better approach might be to 
combine conversion buffer and the final glob() result buffer 
(which also includes directory name, and currently allocated on 
each ngx_read_glob() call).  Though I don't think it worth the 
effort, especially given that ngx_read_glob() is only used during 
configuration parsing.

As for NGX_MAX_PATH, it does not look like a good replacement for 
a number of reasons.  In particular, a) it might be incorrectly 
interpreted as a place when only paths up to MAX_PATH are 
supported, b) MAX_PATH on win32 is in characters, while the buffer 
in question is in bytes (and to be used for UTF-8), so it is no 
better than NGX_UTF16_BUFLEN.

> > 
> >     if (gl->no_match) {
> >         return NGX_DONE;
> >     }
> > 
> >     if (gl->ready) {
> > -        *name = gl->name;
> > -
> >         gl->ready = 0;
> > -        return NGX_OK;
> > +        goto convert;
> >     }
> > 
> >     ngx_free(gl->name.data);
> >     gl->name.data = NULL;
> > 
> > -    if (FindNextFile(gl->dir, &gl->finddata) != 0) {
> > -
> > -        len = ngx_strlen(gl->finddata.cFileName);
> > -        gl->name.len = gl->last + len;
> > -
> > -        gl->name.data = ngx_alloc(gl->name.len + 1, gl->log);
> > -        if (gl->name.data == NULL) {
> > -            return NGX_ERROR;
> > -        }
> > -
> > -        ngx_memcpy(gl->name.data, gl->pattern, gl->last);
> > -        ngx_cpystrn(gl->name.data + gl->last, (u_char *) gl->finddata.cFileName,
> > -                    len + 1);
> > -
> > -        *name = gl->name;
> > -
> > -        return NGX_OK;
> > +    if (FindNextFileW(gl->dir, &gl->finddata) != 0) {
> > +        goto convert;
> >     }
> > 
> >     err = ngx_errno;
> > @@ -637,6 +629,43 @@ ngx_read_glob(ngx_glob_t *gl, ngx_str_t 
> >                   "FindNextFile(%s) failed", gl->pattern);
> > 
> >     return NGX_ERROR;
> > +
> > +convert:
> > +
> > +    len = NGX_UTF16_BUFLEN;
> > +    p = ngx_utf16_to_utf8(utf8, gl->finddata.cFileName, &len, NULL);
> 
> Note that passing utf8 off the stack can result in an attempt to free
> the stack pointer inside ngx_utf16_to_utf8() on NGX_EILSEQ.

Yes, thanks, this shouldn't be a problem with the 
ngx_utf16_to_utf8() already fixed based on the 1st patch comments.

> > +
> 
> Nitpicking: there (and in subsequent patches) you're starting to add
> an empty line after ngx_utf16_to_utf8(); it's not in the 1st path.

In the first patch there is an empty line before the 
ngx_utf16_to_utf8() call, which somewhat balance things.  Either 
way, added an empty line there as well.

[...]

-- 
Maxim Dounin
http://mdounin.ru/


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