2008/4/29 Chris Kukuchka <[EMAIL PROTECTED]>:
> Aivars Šterns wrote:
>
> > Yes, but this is not how apache could handle this, we need argv[], but
> there
> > is no way to get this from apache right?
> >
> >
>
> In server/main.c, argv gets linked to the process_rec structure during the
> process startup. Further, according to include/httpd.h, the process_rec
> structure can be reached through the request_rec structure
> (r->connection->server->process). As such, argv[] should be available for
> reading most anywhere in Apache.
>
> As far as the safety of making changes to those values is concerned, I have
> no advise beyond, "proceed with caution." Especially if you intend on
> placing raw request data there.
Although you can get access to argv[], you can only change the value
of argv[0], at least for the purposes of effecting the output from
'ps'. This is because that argv[] is not the original argv[] and thus
modules could have substituted the program arguments, ie., argv[1] and
beyond. This means that any value you substitute must fit into the
original length of argv[0] and cannot flow over into the additional
arguments.
Some code form mod_wsgi:
static void wsgi_setup_daemon_name(WSGIDaemonProcess *daemon, apr_pool_t *p)
{
const char *display_name = NULL;
int slen = 0;
int dlen = 0;
char *argv0 = NULL;
display_name = daemon->group->display_name;
if (!display_name)
return;
if (!strcmp(display_name, "%{GROUP}")) {
display_name = apr_pstrcat(p, "(wsgi:", daemon->group->name,
")", NULL);
}
/*
* Only argv[0] is guaranteed to be the real things as MPM
* modules may make modifications to subsequent arguments.
* Thus can only replace the argv[0] value. Because length
* is restricted, need to truncate display name if too long.
*/
argv0 = (char*)wsgi_server->process->argv[0];
dlen = strlen(argv0);
slen = strlen(display_name);
memset(argv0, ' ', dlen);
if (slen < dlen)
memcpy(argv0, display_name, slen);
else
memcpy(argv0, display_name, dlen);
}
The wsgi_server variable is a cached reference to server_rec structure.
Graham
