[nginx] Perl: protection against duplicate $r->sleep() calls.

[Maxim Dounin]

details:   https://hg.nginx.org/nginx/rev/02cd116ebe2a
branches:  
changeset: 7527:02cd116ebe2a
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Fri Jul 12 15:34:37 2019 +0300
description:
Perl: protection against duplicate $r->sleep() calls.

Duplicate $r->sleep() and/or $r->has_request_body() calls result
in undefined behaviour (in practice, connection leaks were observed).
To prevent this, croak() added in appropriate places.

diffstat:

 src/http/modules/perl/nginx.xs |  8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diffs (25 lines):

diff --git a/src/http/modules/perl/nginx.xs b/src/http/modules/perl/nginx.xs
--- a/src/http/modules/perl/nginx.xs
+++ b/src/http/modules/perl/nginx.xs
@@ -400,6 +400,10 @@ has_request_body(r, next)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->next) {
+        croak("has_request_body(): another handler active");
+    }
+
     if (r->headers_in.content_length_n <= 0 && !r->headers_in.chunked) {
         XSRETURN_UNDEF;
     }
@@ -1093,6 +1097,10 @@ sleep(r, sleep, next)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->next) {
+        croak("sleep(): another handler active");
+    }
+
     sleep = (ngx_msec_t) SvIV(ST(1));
 
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,