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Posted to cvs@httpd.apache.org by yl...@apache.org on 2021/09/03 16:52:39 UTC

svn commit: r1892874 - in /httpd/httpd/branches/2.4.x: ./ changes-entries/fix_uds_filename.txt modules/proxy/mod_proxy.c modules/proxy/proxy_util.c

Author: ylavic
Date: Fri Sep  3 16:52:38 2021
New Revision: 1892874

URL: http://svn.apache.org/viewvc?rev=1892874&view=rev
Log:
Merge r1892814, r1892853 from trunk:

mod_proxy: Faster unix socket path parsing in the "proxy:" URL.

The actual r->filename format is "[proxy:]unix:path|url" for UDS, no need to
strstr(,"unix:") since it's at the start of the string.


mod_proxy: Follow up to r1892814.

Save some few cycles in ap_proxy_de_socketfy() too.


Submitted by: ylavic
Reviewed by: ylavic, covener, rpluem

Added:
    httpd/httpd/branches/2.4.x/changes-entries/fix_uds_filename.txt
      - copied unchanged from r1892814, httpd/httpd/trunk/changes-entries/fix_uds_filename.txt
Modified:
    httpd/httpd/branches/2.4.x/   (props changed)
    httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c
    httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c

Propchange: httpd/httpd/branches/2.4.x/
------------------------------------------------------------------------------
  Merged /httpd/httpd/trunk:r1892814,1892853

Modified: httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c?rev=1892874&r1=1892873&r2=1892874&view=diff
==============================================================================
--- httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c (original)
+++ httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c Fri Sep  3 16:52:38 2021
@@ -1975,7 +1975,7 @@ PROXY_DECLARE(const char *) ap_proxy_de_
      * the UDS path... ignore it
      */
     if (!ap_cstr_casecmpn(url, "unix:", 5) &&
-        ((ptr = ap_strchr_c(url, '|')) != NULL)) {
+        ((ptr = ap_strchr_c(url + 5, '|')) != NULL)) {
         /* move past the 'unix:...|' UDS path info */
         const char *ret, *c;
 

Modified: httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c?rev=1892874&r1=1892873&r2=1892874&view=diff
==============================================================================
--- httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c (original)
+++ httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c Fri Sep  3 16:52:38 2021
@@ -2281,8 +2281,8 @@ static void fix_uds_filename(request_rec
     if (!r || !r->filename) return;
 
     if (!strncmp(r->filename, "proxy:", 6) &&
-            (ptr2 = ap_strcasestr(r->filename, "unix:")) &&
-            (ptr = ap_strchr(ptr2, '|'))) {
+            !ap_cstr_casecmpn(r->filename + 6, "unix:", 5) &&
+            (ptr2 = r->filename + 6 + 5, ptr = ap_strchr(ptr2, '|'))) {
         apr_uri_t urisock;
         apr_status_t rv;
         *ptr = '\0';



Re: svn commit: r1892874 - in /httpd/httpd/branches/2.4.x: ./ changes-entries/fix_uds_filename.txt modules/proxy/mod_proxy.c modules/proxy/proxy_util.c

Posted by Ruediger Pluem <rp...@apache.org>.

On 9/6/21 12:28 PM, Yann Ylavic wrote:
> On Mon, Sep 6, 2021 at 12:16 PM Ruediger Pluem <rp...@apache.org> wrote:
>>
          !ap_cstr_casecmpn(uds_url, "unix:", 5) &&
>>
>> Why doing case insensitive checks here? Shouldn't we insist on case here and use strncmp ?
> 
> Yes, correct, spurious change.
> 

>>> +        {
>>> +            apr_table_setn(r->notes, "uds_path", uds_path);
>>> +
>>> +            /* Remove the UDS path from *url and r->filename */
>>> +            url_len = strlen(origin_url);
>>> +            *url = apr_pstrmemdup(r->pool, origin_url, url_len);
>>> +            memcpy(uds_url, *url, url_len + 1);
>>
>> With a short uds path and a long origin_url couldn't this be overlapping?
>> I think memcpy is unsafe with overlapping memory and we should stay with memmove.
> 
> *url is newly allocated here, so there is no possible overlap with the
> initial r->filename.

Good point. I missed this.

Regards

Rüdiger


Re: svn commit: r1892874 - in /httpd/httpd/branches/2.4.x: ./ changes-entries/fix_uds_filename.txt modules/proxy/mod_proxy.c modules/proxy/proxy_util.c

Posted by Yann Ylavic <yl...@gmail.com>.
On Mon, Sep 6, 2021 at 12:16 PM Ruediger Pluem <rp...@apache.org> wrote:
>
> On 9/6/21 11:38 AM, Yann Ylavic wrote:
> > Index: modules/proxy/proxy_util.c
> > ===================================================================
> > --- modules/proxy/proxy_util.c        (revision 1892971)
> > +++ modules/proxy/proxy_util.c        (working copy)
> > @@ -2268,33 +2268,45 @@ static int ap_proxy_retry_worker(const char *proxy
> >   * were passed a UDS url (eg: from mod_proxy) and adjust uds_path
> >   * as required.
> >   */
> > -static void fix_uds_filename(request_rec *r, char **url)
> > +static int fix_uds_filename(request_rec *r, char **url)
> >  {
> > -    char *ptr, *ptr2;
> > -    if (!r || !r->filename) return;
> > +    char *uds_url = r->filename + 6, *origin_url;
> >
> > -    if (!strncmp(r->filename, "proxy:", 6) &&
> > -            !ap_cstr_casecmpn(r->filename + 6, "unix:", 5) &&
> > -            (ptr2 = r->filename + 6 + 5, ptr = ap_strchr(ptr2, '|'))) {
> > +    if (!ap_cstr_casecmpn(r->filename, "proxy:", 6) &&
> > +            !ap_cstr_casecmpn(uds_url, "unix:", 5) &&
>
> Why doing case insensitive checks here? Shouldn't we insist on case here and use strncmp ?

Yes, correct, spurious change.

>
> > +            (origin_url = ap_strchr(uds_url + 5, '|'))) {
> > +        char *uds_path = NULL;
> > +        apr_size_t url_len;
> >          apr_uri_t urisock;
> >          apr_status_t rv;
> > -        *ptr = '\0';
> > -        rv = apr_uri_parse(r->pool, ptr2, &urisock);
> > -        if (rv == APR_SUCCESS) {
> > -            char *rurl = ptr+1;
> > -            char *sockpath = ap_runtime_dir_relative(r->pool, urisock.path);
> > -            apr_table_setn(r->notes, "uds_path", sockpath);
> > -            *url = apr_pstrdup(r->pool, rurl); /* so we get the scheme for the uds */
> > -            /* r->filename starts w/ "proxy:", so add after that */
> > -            memmove(r->filename+6, rurl, strlen(rurl)+1);
> > +
> > +        *origin_url = '\0';
> > +        rv = apr_uri_parse(r->pool, uds_url, &urisock);
> > +        *origin_url++ = '|';
> > +
> > +        if (rv == APR_SUCCESS && urisock.path && !urisock.hostname) {
> > +            uds_path = ap_runtime_dir_relative(r->pool, urisock.path);
> > +        }
> > +        if (!uds_path) {
> > +            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO()
> > +                    "Invalid proxy UDS filename (%s)",
> > +                    r->filename);
> > +            return 0;
> > +        }
> > +        {
> > +            apr_table_setn(r->notes, "uds_path", uds_path);
> > +
> > +            /* Remove the UDS path from *url and r->filename */
> > +            url_len = strlen(origin_url);
> > +            *url = apr_pstrmemdup(r->pool, origin_url, url_len);
> > +            memcpy(uds_url, *url, url_len + 1);
>
> With a short uds path and a long origin_url couldn't this be overlapping?
> I think memcpy is unsafe with overlapping memory and we should stay with memmove.

*url is newly allocated here, so there is no possible overlap with the
initial r->filename.


Regards;
Yann.

Re: svn commit: r1892874 - in /httpd/httpd/branches/2.4.x: ./ changes-entries/fix_uds_filename.txt modules/proxy/mod_proxy.c modules/proxy/proxy_util.c

Posted by Ruediger Pluem <rp...@apache.org>.

On 9/6/21 11:38 AM, Yann Ylavic wrote:
> Index: modules/proxy/proxy_util.c
> ===================================================================
> --- modules/proxy/proxy_util.c	(revision 1892971)
> +++ modules/proxy/proxy_util.c	(working copy)
> @@ -2268,33 +2268,45 @@ static int ap_proxy_retry_worker(const char *proxy
>   * were passed a UDS url (eg: from mod_proxy) and adjust uds_path
>   * as required.  
>   */
> -static void fix_uds_filename(request_rec *r, char **url) 
> +static int fix_uds_filename(request_rec *r, char **url) 
>  {
> -    char *ptr, *ptr2;
> -    if (!r || !r->filename) return;
> +    char *uds_url = r->filename + 6, *origin_url;
>  
> -    if (!strncmp(r->filename, "proxy:", 6) &&
> -            !ap_cstr_casecmpn(r->filename + 6, "unix:", 5) &&
> -            (ptr2 = r->filename + 6 + 5, ptr = ap_strchr(ptr2, '|'))) {
> +    if (!ap_cstr_casecmpn(r->filename, "proxy:", 6) &&
> +            !ap_cstr_casecmpn(uds_url, "unix:", 5) &&

Why doing case insensitive checks here? Shouldn't we insist on case here and use strncmp ?

> +            (origin_url = ap_strchr(uds_url + 5, '|'))) {
> +        char *uds_path = NULL;
> +        apr_size_t url_len;
>          apr_uri_t urisock;
>          apr_status_t rv;
> -        *ptr = '\0';
> -        rv = apr_uri_parse(r->pool, ptr2, &urisock);
> -        if (rv == APR_SUCCESS) {
> -            char *rurl = ptr+1;
> -            char *sockpath = ap_runtime_dir_relative(r->pool, urisock.path);
> -            apr_table_setn(r->notes, "uds_path", sockpath);
> -            *url = apr_pstrdup(r->pool, rurl); /* so we get the scheme for the uds */
> -            /* r->filename starts w/ "proxy:", so add after that */
> -            memmove(r->filename+6, rurl, strlen(rurl)+1);
> +
> +        *origin_url = '\0';
> +        rv = apr_uri_parse(r->pool, uds_url, &urisock);
> +        *origin_url++ = '|';
> +
> +        if (rv == APR_SUCCESS && urisock.path && !urisock.hostname) {
> +            uds_path = ap_runtime_dir_relative(r->pool, urisock.path);
> +        }
> +        if (!uds_path) {
> +            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO()
> +                    "Invalid proxy UDS filename (%s)",
> +                    r->filename);
> +            return 0;
> +        }
> +        {
> +            apr_table_setn(r->notes, "uds_path", uds_path);
> +
> +            /* Remove the UDS path from *url and r->filename */
> +            url_len = strlen(origin_url);
> +            *url = apr_pstrmemdup(r->pool, origin_url, url_len);
> +            memcpy(uds_url, *url, url_len + 1);

With a short uds path and a long origin_url couldn't this be overlapping?
I think memcpy is unsafe with overlapping memory and we should stay with memmove.

> +
>              ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
>                      "*: rewrite of url due to UDS(%s): %s (%s)",
> -                    sockpath, *url, r->filename);
> +                    uds_path, *url, r->filename);
>          }
> -        else {
> -            *ptr = '|';
> -        }
>      }
> +    return 1;
>  }
>  

Regards

Rüdiger


Re: svn commit: r1892874 - in /httpd/httpd/branches/2.4.x: ./ changes-entries/fix_uds_filename.txt modules/proxy/mod_proxy.c modules/proxy/proxy_util.c

Posted by Yann Ylavic <yl...@gmail.com>.
On Fri, Sep 3, 2021 at 10:11 PM Ruediger Pluem <rp...@apache.org> wrote:
>
>
>
> On 9/3/21 6:52 PM, ylavic@apache.org wrote:
> >
> >      if (!strncmp(r->filename, "proxy:", 6) &&
> > -            (ptr2 = ap_strcasestr(r->filename, "unix:")) &&
> > -            (ptr = ap_strchr(ptr2, '|'))) {
> > +            !ap_cstr_casecmpn(r->filename + 6, "unix:", 5) &&
> > +            (ptr2 = r->filename + 6 + 5, ptr = ap_strchr(ptr2, '|'))) {
>
> I know that I voted for it to be backported, but after rethinking this shouldn't this be
>
> (ptr2 = r->filename + 6, ptr = ap_strchr(ptr2 + 5, '|')))
>
> as ptr2 is later used in
>
>         rv = apr_uri_parse(r->pool, ptr2, &urisock);
>
> With the old code and with my proposal above ptr2 points to the 'u' of 'unix:' with the current code it points to the char after
> 'unix:' likely //.

An UDS url in r->filename should be of the form
"proxy:unix:/path/to/socket|https://www.example.net/...", configured
either from a ProxyPass, a SetHandler or a RewriteRule [P]. So ptr2
should point to a path (absolute or relative to ServerRoot), not an
authority starting with "//".

But if we want a better validation at fix_uds_filename() level, maybe
something like the attached patch could do?

Regards;
Yann.

Re: svn commit: r1892874 - in /httpd/httpd/branches/2.4.x: ./ changes-entries/fix_uds_filename.txt modules/proxy/mod_proxy.c modules/proxy/proxy_util.c

Posted by Ruediger Pluem <rp...@apache.org>.

On 9/3/21 6:52 PM, ylavic@apache.org wrote:
> Author: ylavic
> Date: Fri Sep  3 16:52:38 2021
> New Revision: 1892874
> 
> URL: http://svn.apache.org/viewvc?rev=1892874&view=rev
> Log:
> Merge r1892814, r1892853 from trunk:
> 
> mod_proxy: Faster unix socket path parsing in the "proxy:" URL.
> 
> The actual r->filename format is "[proxy:]unix:path|url" for UDS, no need to
> strstr(,"unix:") since it's at the start of the string.
> 
> 
> mod_proxy: Follow up to r1892814.
> 
> Save some few cycles in ap_proxy_de_socketfy() too.
> 
> 
> Submitted by: ylavic
> Reviewed by: ylavic, covener, rpluem
> 
> Added:
>     httpd/httpd/branches/2.4.x/changes-entries/fix_uds_filename.txt
>       - copied unchanged from r1892814, httpd/httpd/trunk/changes-entries/fix_uds_filename.txt
> Modified:
>     httpd/httpd/branches/2.4.x/   (props changed)
>     httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c
>     httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c
> 
> Propchange: httpd/httpd/branches/2.4.x/
> ------------------------------------------------------------------------------
>   Merged /httpd/httpd/trunk:r1892814,1892853
> 
> Modified: httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c?rev=1892874&r1=1892873&r2=1892874&view=diff
> ==============================================================================
> --- httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c (original)
> +++ httpd/httpd/branches/2.4.x/modules/proxy/mod_proxy.c Fri Sep  3 16:52:38 2021
> @@ -1975,7 +1975,7 @@ PROXY_DECLARE(const char *) ap_proxy_de_
>       * the UDS path... ignore it
>       */
>      if (!ap_cstr_casecmpn(url, "unix:", 5) &&
> -        ((ptr = ap_strchr_c(url, '|')) != NULL)) {
> +        ((ptr = ap_strchr_c(url + 5, '|')) != NULL)) {
>          /* move past the 'unix:...|' UDS path info */
>          const char *ret, *c;
>  
> 
> Modified: httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c?rev=1892874&r1=1892873&r2=1892874&view=diff
> ==============================================================================
> --- httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c (original)
> +++ httpd/httpd/branches/2.4.x/modules/proxy/proxy_util.c Fri Sep  3 16:52:38 2021
> @@ -2281,8 +2281,8 @@ static void fix_uds_filename(request_rec
>      if (!r || !r->filename) return;
>  
>      if (!strncmp(r->filename, "proxy:", 6) &&
> -            (ptr2 = ap_strcasestr(r->filename, "unix:")) &&
> -            (ptr = ap_strchr(ptr2, '|'))) {
> +            !ap_cstr_casecmpn(r->filename + 6, "unix:", 5) &&
> +            (ptr2 = r->filename + 6 + 5, ptr = ap_strchr(ptr2, '|'))) {

I know that I voted for it to be backported, but after rethinking this shouldn't this be

(ptr2 = r->filename + 6, ptr = ap_strchr(ptr2 + 5, '|')))

as ptr2 is later used in

        rv = apr_uri_parse(r->pool, ptr2, &urisock);

With the old code and with my proposal above ptr2 points to the 'u' of 'unix:' with the current code it points to the char after
'unix:' likely //.

Regards

Rüdiger