[PATCH 3 of 3] Headers filter: added "add_trailer" directive
Piotr Sikora
piotrsikora at google.com
Sat Jun 3 03:33:47 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 acdc80c0d4ef8aa2519e2882ff1a3bd4a316ad81
# Parent 8d74ff6c2015180f5c1f399f492214d7d0a52b3f
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 8d74ff6c2015 -r acdc80c0d4ef 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;
@@ -72,6 +73,8 @@ static char *ngx_http_headers_expires(ng
void *conf);
static char *ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
+static char *ngx_http_headers_add_trailer(ngx_conf_t *cf, ngx_command_t *cmd,
+ void *conf);
static ngx_http_set_header_t ngx_http_set_headers[] = {
@@ -108,6 +111,14 @@ static ngx_command_t ngx_http_headers_f
0,
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_trailer,
+ NGX_HTTP_LOC_CONF_OFFSET,
+ 0,
+ NULL },
+
ngx_null_command
};
@@ -144,6 +155,7 @@ 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 +166,15 @@ 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 +223,103 @@ 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;
+ }
+
+ if (h[i].value.value.len) {
+ 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 +666,7 @@ 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 +697,10 @@ 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 +711,9 @@ 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;
}
@@ -741,3 +858,63 @@ ngx_http_headers_add(ngx_conf_t *cf, ngx
return NGX_CONF_OK;
}
+
+
+static char *
+ngx_http_headers_add_trailer(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
+{
+ ngx_http_headers_conf_t *hcf = conf;
+
+ ngx_str_t *value;
+ ngx_http_header_val_t *hv;
+ ngx_http_compile_complex_value_t ccv;
+
+ value = cf->args->elts;
+
+ if (hcf->trailers == NULL) {
+ hcf->trailers = ngx_array_create(cf->pool, 1,
+ sizeof(ngx_http_header_val_t));
+ if (hcf->trailers == NULL) {
+ return NGX_CONF_ERROR;
+ }
+ }
+
+ hv = ngx_array_push(hcf->trailers);
+ if (hv == NULL) {
+ return NGX_CONF_ERROR;
+ }
+
+ hv->key = value[1];
+ hv->handler = NULL;
+ hv->offset = 0;
+ hv->always = 0;
+
+ if (value[2].len == 0) {
+ ngx_memzero(&hv->value, sizeof(ngx_http_complex_value_t));
+
+ } else {
+ ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
+
+ ccv.cf = cf;
+ ccv.value = &value[2];
+ ccv.complex_value = &hv->value;
+
+ if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
+ return NGX_CONF_ERROR;
+ }
+ }
+
+ if (cf->args->nelts == 3) {
+ return NGX_CONF_OK;
+ }
+
+ if (ngx_strcmp(value[3].data, "always") != 0) {
+ ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+ "invalid parameter \"%V\"", &value[3]);
+ return NGX_CONF_ERROR;
+ }
+
+ hv->always = 1;
+
+ return NGX_CONF_OK;
+}
More information about the nginx-devel
mailing list