# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1562934931 -10800
# Node ID 0cb693b4cbbb3231c91d0b3f40e1a17472d6eed9
# Parent  02cd116ebe2a80c8d16a40085a30110def8cf67f
Perl: disabled unrelated calls from variable handlers.

Variable handlers are not expected to send anything to the client, cannot
sleep or read body, and are not expected to modify the request.  Added
appropriate protection to prevent accidental foot shooting.

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
@@ -110,6 +110,10 @@ status(r, code)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->variable) {
+        croak("status(): cannot be used in variable handler");
+    }
+
     r->headers_out.status = SvIV(ST(1));
 
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
@@ -133,6 +137,10 @@ send_http_header(r, ...)
         croak("send_http_header(): called after error");
     }
 
+    if (ctx->variable) {
+        croak("send_http_header(): cannot be used in variable handler");
+    }
+
     if (r->headers_out.status == 0) {
         r->headers_out.status = NGX_HTTP_OK;
     }
@@ -400,6 +408,10 @@ has_request_body(r, next)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->variable) {
+        croak("has_request_body(): cannot be used in variable handler");
+    }
+
     if (ctx->next) {
         croak("has_request_body(): another handler active");
     }
@@ -526,6 +538,10 @@ discard_request_body(r)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->variable) {
+        croak("discard_request_body(): cannot be used in variable handler");
+    }
+
     rc = ngx_http_discard_request_body(r);
 
     if (rc != NGX_OK) {
@@ -551,6 +567,10 @@ header_out(r, key, value)
         croak("header_out(): called after error");
     }
 
+    if (ctx->variable) {
+        croak("header_out(): cannot be used in variable handler");
+    }
+
     key = ST(1);
     value = ST(2);
 
@@ -640,6 +660,10 @@ print(r, ...)
         croak("print(): called after error");
     }
 
+    if (ctx->variable) {
+        croak("print(): cannot be used in variable handler");
+    }
+
     if (items == 2) {
 
         /*
@@ -750,6 +774,10 @@ sendfile(r, filename, offset = -1, bytes
         croak("sendfile(): called after error");
     }
 
+    if (ctx->variable) {
+        croak("sendfile(): cannot be used in variable handler");
+    }
+
     filename = SvPV_nolen(ST(1));
 
     if (filename == NULL) {
@@ -852,6 +880,10 @@ flush(r)
         croak("flush(): called after error");
     }
 
+    if (ctx->variable) {
+        croak("flush(): cannot be used in variable handler");
+    }
+
     b = ngx_calloc_buf(r->pool);
     if (b == NULL) {
         ctx->error = 1;
@@ -883,6 +915,10 @@ internal_redirect(r, uri)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->variable) {
+        croak("internal_redirect(): cannot be used in variable handler");
+    }
+
     uri = ST(1);
 
     if (ngx_http_perl_sv2str(aTHX_ r, &ctx->redirect_uri, uri) != NGX_OK) {
@@ -911,6 +947,10 @@ allow_ranges(r)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->variable) {
+        croak("allow_ranges(): cannot be used in variable handler");
+    }
+
     r->allow_ranges = 1;
 
 
@@ -1097,6 +1137,10 @@ sleep(r, sleep, next)
 
     ngx_http_perl_set_request(r, ctx);
 
+    if (ctx->variable) {
+        croak("sleep(): cannot be used in variable handler");
+    }
+
     if (ctx->next) {
         croak("sleep(): another handler active");
     }
diff --git a/src/http/modules/perl/ngx_http_perl_module.c b/src/http/modules/perl/ngx_http_perl_module.c
--- a/src/http/modules/perl/ngx_http_perl_module.c
+++ b/src/http/modules/perl/ngx_http_perl_module.c
@@ -302,6 +302,7 @@ ngx_http_perl_variable(ngx_http_request_
 
     ngx_int_t                   rc;
     ngx_str_t                   value;
+    ngx_uint_t                  saved;
     ngx_http_perl_ctx_t        *ctx;
     ngx_http_perl_main_conf_t  *pmcf;
 
@@ -321,6 +322,9 @@ ngx_http_perl_variable(ngx_http_request_
         ctx->request = r;
     }
 
+    saved = ctx->variable;
+    ctx->variable = 1;
+
     pmcf = ngx_http_get_module_main_conf(r, ngx_http_perl_module);
 
     value.data = NULL;
@@ -347,6 +351,7 @@ ngx_http_perl_variable(ngx_http_request_
         v->not_found = 1;
     }
 
+    ctx->variable = saved;
     ctx->filename.data = NULL;
     ctx->redirect_uri.len = 0;
 
diff --git a/src/http/modules/perl/ngx_http_perl_module.h b/src/http/modules/perl/ngx_http_perl_module.h
--- a/src/http/modules/perl/ngx_http_perl_module.h
+++ b/src/http/modules/perl/ngx_http_perl_module.h
@@ -33,6 +33,7 @@ typedef struct {
 
     unsigned                  done:1;
     unsigned                  error:1;
+    unsigned                  variable:1;
 
     ngx_array_t              *variables;  /* array of ngx_http_perl_var_t */