[PATCH 3 of 3] Headers filter: added "add_trailer" directive
Piotr Sikora
piotrsikora at google.com
Tue Jun 13 12:19:55 UTC 2017
# HG changeset patch
# User Piotr Sikora <piotrsikora at google.com>
# Date 1490351854 25200
# Fri Mar 24 03:37:34 2017 -0700
# Node ID 46150fb672e7b92cfbe678bad71df187fcb25ae6
# Parent 73f67e06ab103e0368d1810c6f8cac5c70c4e246
Headers filter: added "add_trailer" directive.
Trailers added using this directive are evaluated after response body
is processed by output filters (but before it's written to the wire),
so it's possible to use variables calculated from the response body
as the trailer value.
Signed-off-by: Piotr Sikora <piotrsikora at google.com>
diff -r 73f67e06ab10 -r 46150fb672e7 src/http/modules/ngx_http_headers_filter_module.c
--- a/src/http/modules/ngx_http_headers_filter_module.c
+++ b/src/http/modules/ngx_http_headers_filter_module.c
@@ -48,6 +48,7 @@ typedef struct {
time_t expires_time;
ngx_http_complex_value_t *expires_value;
ngx_array_t *headers;
+ ngx_array_t *trailers;
} ngx_http_headers_conf_t;
@@ -105,7 +106,15 @@ static ngx_command_t ngx_http_headers_f
|NGX_CONF_TAKE23,
ngx_http_headers_add,
NGX_HTTP_LOC_CONF_OFFSET,
- 0,
+ offsetof(ngx_http_headers_conf_t, headers),
+ NULL },
+
+ { ngx_string("add_trailer"),
+ NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
+ |NGX_CONF_TAKE23,
+ ngx_http_headers_add,
+ NGX_HTTP_LOC_CONF_OFFSET,
+ offsetof(ngx_http_headers_conf_t, trailers),
NULL },
ngx_null_command
@@ -144,6 +153,7 @@ ngx_module_t ngx_http_headers_filter_mo
static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
+static ngx_http_output_body_filter_pt ngx_http_next_body_filter;
static ngx_int_t
@@ -154,10 +164,15 @@ ngx_http_headers_filter(ngx_http_request
ngx_http_header_val_t *h;
ngx_http_headers_conf_t *conf;
+ if (r != r->main) {
+ return ngx_http_next_header_filter(r);
+ }
+
conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module);
- if ((conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL)
- || r != r->main)
+ if (conf->expires == NGX_HTTP_EXPIRES_OFF
+ && conf->headers == NULL
+ && conf->trailers == NULL)
{
return ngx_http_next_header_filter(r);
}
@@ -206,11 +221,101 @@ ngx_http_headers_filter(ngx_http_request
}
}
+ if (conf->trailers) {
+ h = conf->trailers->elts;
+ for (i = 0; i < conf->trailers->nelts; i++) {
+
+ if (!safe_status && !h[i].always) {
+ continue;
+ }
+
+ r->expect_trailers = 1;
+ break;
+ }
+ }
+
return ngx_http_next_header_filter(r);
}
static ngx_int_t
+ngx_http_trailers_filter(ngx_http_request_t *r, ngx_chain_t *in)
+{
+ ngx_str_t value;
+ ngx_uint_t i, safe_status;
+ ngx_chain_t *cl;
+ ngx_table_elt_t *t;
+ ngx_http_header_val_t *h;
+ ngx_http_headers_conf_t *conf;
+
+ conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module);
+
+ if (in == NULL
+ || conf->trailers == NULL
+ || !r->expect_trailers
+ || r->header_only)
+ {
+ return ngx_http_next_body_filter(r, in);
+ }
+
+ for (cl = in; cl; cl = cl->next) {
+ if (cl->buf->last_buf) {
+ break;
+ }
+ }
+
+ if (cl == NULL) {
+ return ngx_http_next_body_filter(r, in);
+ }
+
+ switch (r->headers_out.status) {
+
+ case NGX_HTTP_OK:
+ case NGX_HTTP_CREATED:
+ case NGX_HTTP_NO_CONTENT:
+ case NGX_HTTP_PARTIAL_CONTENT:
+ case NGX_HTTP_MOVED_PERMANENTLY:
+ case NGX_HTTP_MOVED_TEMPORARILY:
+ case NGX_HTTP_SEE_OTHER:
+ case NGX_HTTP_NOT_MODIFIED:
+ case NGX_HTTP_TEMPORARY_REDIRECT:
+ case NGX_HTTP_PERMANENT_REDIRECT:
+ safe_status = 1;
+ break;
+
+ default:
+ safe_status = 0;
+ break;
+ }
+
+ h = conf->trailers->elts;
+ for (i = 0; i < conf->trailers->nelts; i++) {
+
+ if (!safe_status && !h[i].always) {
+ continue;
+ }
+
+ if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) {
+ return NGX_ERROR;
+ }
+
+ if (value.len) {
+ t = ngx_list_push(&r->headers_out.trailers);
+ if (t == NULL) {
+ return NGX_ERROR;
+ }
+
+ t->key = h[i].key;
+ t->value = value;
+ t->hash = 1;
+ }
+ }
+
+ return ngx_http_next_body_filter(r, in);
+}
+
+
+static ngx_int_t
ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf)
{
char *err;
@@ -557,6 +662,7 @@ ngx_http_headers_create_conf(ngx_conf_t
* set by ngx_pcalloc():
*
* conf->headers = NULL;
+ * conf->trailers = NULL;
* conf->expires_time = 0;
* conf->expires_value = NULL;
*/
@@ -587,6 +693,10 @@ ngx_http_headers_merge_conf(ngx_conf_t *
conf->headers = prev->headers;
}
+ if (conf->trailers == NULL) {
+ conf->trailers = prev->trailers;
+ }
+
return NGX_CONF_OK;
}
@@ -597,6 +707,9 @@ ngx_http_headers_filter_init(ngx_conf_t
ngx_http_next_header_filter = ngx_http_top_header_filter;
ngx_http_top_header_filter = ngx_http_headers_filter;
+ ngx_http_next_body_filter = ngx_http_top_body_filter;
+ ngx_http_top_body_filter = ngx_http_trailers_filter;
+
return NGX_OK;
}
@@ -674,42 +787,49 @@ ngx_http_headers_add(ngx_conf_t *cf, ngx
{
ngx_http_headers_conf_t *hcf = conf;
- ngx_str_t *value;
- ngx_uint_t i;
- ngx_http_header_val_t *hv;
- ngx_http_set_header_t *set;
- ngx_http_compile_complex_value_t ccv;
+ ngx_str_t *value;
+ ngx_uint_t i;
+ ngx_array_t **headers;
+ ngx_http_header_val_t *hv;
+ ngx_http_set_header_t *set;
+ ngx_http_compile_complex_value_t ccv;
value = cf->args->elts;
- if (hcf->headers == NULL) {
- hcf->headers = ngx_array_create(cf->pool, 1,
- sizeof(ngx_http_header_val_t));
- if (hcf->headers == NULL) {
+ headers = (ngx_array_t **) ((char *) hcf + cmd->offset);
+
+ if (*headers == NULL) {
+ *headers = ngx_array_create(cf->pool, 1,
+ sizeof(ngx_http_header_val_t));
+ if (*headers == NULL) {
return NGX_CONF_ERROR;
}
}
- hv = ngx_array_push(hcf->headers);
+ hv = ngx_array_push(*headers);
if (hv == NULL) {
return NGX_CONF_ERROR;
}
hv->key = value[1];
- hv->handler = ngx_http_add_header;
+ hv->handler = NULL;
hv->offset = 0;
hv->always = 0;
- set = ngx_http_set_headers;
- for (i = 0; set[i].name.len; i++) {
- if (ngx_strcasecmp(value[1].data, set[i].name.data) != 0) {
- continue;
+ if (headers == &hcf->headers) {
+ hv->handler = ngx_http_add_header;
+
+ set = ngx_http_set_headers;
+ for (i = 0; set[i].name.len; i++) {
+ if (ngx_strcasecmp(value[1].data, set[i].name.data) != 0) {
+ continue;
+ }
+
+ hv->offset = set[i].offset;
+ hv->handler = set[i].handler;
+
+ break;
}
-
- hv->offset = set[i].offset;
- hv->handler = set[i].handler;
-
- break;
}
if (value[2].len == 0) {
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