Entity tags: downgrade strong etags to weak ones as needed.
See http://mailman.nginx.org/pipermail/nginx-devel/2013-November/004523.html.
diff --git a/src/http/modules/ngx_http_addition_filter_module.c b/src/http/modules/ngx_http_addition_filter_module.c
index f598cea..db4970b 100644
--- a/src/http/modules/ngx_http_addition_filter_module.c
+++ b/src/http/modules/ngx_http_addition_filter_module.c
@@ -121,7 +121,7 @@
ngx_http_clear_content_length(r);
ngx_http_clear_accept_ranges(r);
- ngx_http_clear_etag(r);
+ ngx_http_weak_etag(r);
return ngx_http_next_header_filter(r);
}
diff --git a/src/http/modules/ngx_http_gunzip_filter_module.c b/src/http/modules/ngx_http_gunzip_filter_module.c
index adadc9d..70ec0aa 100644
--- a/src/http/modules/ngx_http_gunzip_filter_module.c
+++ b/src/http/modules/ngx_http_gunzip_filter_module.c
@@ -165,7 +165,7 @@
ngx_http_clear_content_length(r);
ngx_http_clear_accept_ranges(r);
- ngx_http_clear_etag(r);
+ ngx_http_weak_etag(r);
return ngx_http_next_header_filter(r);
}
diff --git a/src/http/modules/ngx_http_gzip_filter_module.c b/src/http/modules/ngx_http_gzip_filter_module.c
index ea1f1d0..c57a4a3 100644
--- a/src/http/modules/ngx_http_gzip_filter_module.c
+++ b/src/http/modules/ngx_http_gzip_filter_module.c
@@ -306,7 +306,7 @@
ngx_http_clear_content_length(r);
ngx_http_clear_accept_ranges(r);
- ngx_http_clear_etag(r);
+ ngx_http_weak_etag(r);
return ngx_http_next_header_filter(r);
}
diff --git a/src/http/modules/ngx_http_ssi_filter_module.c b/src/http/modules/ngx_http_ssi_filter_module.c
index aeb1376..8236320 100644
--- a/src/http/modules/ngx_http_ssi_filter_module.c
+++ b/src/http/modules/ngx_http_ssi_filter_module.c
@@ -369,10 +369,13 @@
if (r == r->main) {
ngx_http_clear_content_length(r);
ngx_http_clear_accept_ranges(r);
- ngx_http_clear_etag(r);
if (!slcf->last_modified) {
ngx_http_clear_last_modified(r);
+ ngx_http_clear_etag(r);
+
+ } else {
+ ngx_http_weak_etag(r);
}
}
diff --git a/src/http/modules/ngx_http_sub_filter_module.c b/src/http/modules/ngx_http_sub_filter_module.c
index 3ba59d6..5e6e038 100644
--- a/src/http/modules/ngx_http_sub_filter_module.c
+++ b/src/http/modules/ngx_http_sub_filter_module.c
@@ -175,10 +175,13 @@
if (r == r->main) {
ngx_http_clear_content_length(r);
- ngx_http_clear_etag(r);
if (!slcf->last_modified) {
ngx_http_clear_last_modified(r);
+ ngx_http_clear_etag(r);
+
+ } else {
+ ngx_http_weak_etag(r);
}
}
diff --git a/src/http/modules/ngx_http_xslt_filter_module.c b/src/http/modules/ngx_http_xslt_filter_module.c
index 9e85693..315081e 100644
--- a/src/http/modules/ngx_http_xslt_filter_module.c
+++ b/src/http/modules/ngx_http_xslt_filter_module.c
@@ -337,12 +337,14 @@
r->headers_out.content_length = NULL;
}
- ngx_http_clear_etag(r);
-
conf = ngx_http_get_module_loc_conf(r, ngx_http_xslt_filter_module);
if (!conf->last_modified) {
ngx_http_clear_last_modified(r);
+ ngx_http_clear_etag(r);
+
+ } else {
+ ngx_http_weak_etag(r);
}
}
diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index fb02dd4..2947ad3 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -1851,6 +1851,46 @@
}
+void
+ngx_http_weak_etag(ngx_http_request_t *r)
+{
+ size_t len;
+ u_char *p;
+ ngx_table_elt_t *etag;
+
+ etag = r->headers_out.etag;
+
+ if (etag == NULL) {
+ return;
+ }
+
+ if (etag->value.len > 2
+ && etag->value.data[0] == 'W'
+ && etag->value.data[1] == '/')
+ {
+ return;
+ }
+
+ if (etag->value.len < 1 || etag->value.data[0] != '"') {
+ r->headers_out.etag->hash = 0;
+ r->headers_out.etag = NULL;
+ return;
+ }
+
+ p = ngx_pnalloc(r->pool, etag->value.len + 2);
+ if (p == NULL) {
+ r->headers_out.etag->hash = 0;
+ r->headers_out.etag = NULL;
+ return;
+ }
+
+ len = ngx_sprintf(p, "W/%V", &etag->value) - p;
+
+ etag->value.data = p;
+ etag->value.len = len;
+}
+
+
ngx_int_t
ngx_http_send_response(ngx_http_request_t *r, ngx_uint_t status,
ngx_str_t *ct, ngx_http_complex_value_t *cv)
diff --git a/src/http/ngx_http_core_module.h b/src/http/ngx_http_core_module.h
index 799d2fe..285120d 100644
--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -501,6 +501,7 @@
ngx_int_t ngx_http_set_content_type(ngx_http_request_t *r);
void ngx_http_set_exten(ngx_http_request_t *r);
ngx_int_t ngx_http_set_etag(ngx_http_request_t *r);
+void ngx_http_weak_etag(ngx_http_request_t *r);
ngx_int_t ngx_http_send_response(ngx_http_request_t *r, ngx_uint_t status,
ngx_str_t *ct, ngx_http_complex_value_t *cv);
u_char *ngx_http_map_uri_to_path(ngx_http_request_t *r, ngx_str_t *name,
