# HG changeset patch
# User Piotr Sikora <piotrsik...@google.com>
# Date 1490351854 25200
# Fri Mar 24 03:37:34 2017 -0700
# Node ID 52201fff87e8c5a096287cf206cdcc14c0d81ce7
# Parent e84aa49c5bc7a3250d4844b581e4bf3ed42db5f5
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 <piotrsik...@google.com>
diff -r e84aa49c5bc7 -r 52201fff87e8
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
};
@@ -144,20 +155,30 @@ 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
ngx_http_headers_filter(ngx_http_request_t *r)
{
- ngx_str_t value;
- ngx_uint_t i, safe_status;
- ngx_http_header_val_t *h;
- ngx_http_headers_conf_t *conf;
+ u_char *p, *data;
+ size_t len;
+ ngx_str_t value;
+ ngx_uint_t i, safe_status;
+ ngx_table_elt_t *t;
+ ngx_http_header_val_t *h;
+ ngx_http_headers_conf_t *conf;
+ ngx_http_core_loc_conf_t *clcf;
+
+ 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 +227,162 @@ ngx_http_headers_filter(ngx_http_request
}
}
+ if (conf->trailers) {
+
+ if (r->header_only
+ || r->headers_out.status == NGX_HTTP_NOT_MODIFIED
+ || r->headers_out.status == NGX_HTTP_NO_CONTENT
+ || r->headers_out.status < NGX_HTTP_OK
+ || r->method == NGX_HTTP_HEAD)
+ {
+ return ngx_http_next_header_filter(r);
+ }
+
+ if (r->http_version < NGX_HTTP_VERSION_20) {
+ clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
+
+ if (!clcf->chunked_transfer_encoding) {
+ return ngx_http_next_header_filter(r);
+ }
+ }
+
+ len = 0;
+
+ 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) {
+ len += h[i].key.len + sizeof(", ") - 1;
+ }
+ }
+
+ if (len == 0) {
+ return ngx_http_next_header_filter(r);
+ }
+
+ len -= sizeof(", ") - 1;
+
+ data = ngx_pnalloc(r->pool, len);
+ if (data == NULL) {
+ return NGX_ERROR;
+ }
+
+ t = ngx_list_push(&r->headers_out.headers);
+ if (t == NULL) {
+ return NGX_ERROR;
+ }
+
+ p = data;
+
+ 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) {
+ p = ngx_copy(p, h[i].key.data, h[i].key.len);
+
+ if (p == data + len) {
+ break;
+ }
+
+ *p++ = ','; *p++ = ' ';
+ }
+ }
+
+ ngx_str_set(&t->key, "Trailer");
+ t->value.data = data;
+ t->value.len = len;
+ t->hash = 1;
+
+ r->expect_trailers = 1;
+ }
+
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_PARTIAL_CONTENT:
+ case NGX_HTTP_MOVED_PERMANENTLY:
+ case NGX_HTTP_MOVED_TEMPORARILY:
+ case NGX_HTTP_SEE_OTHER:
+ case NGX_HTTP_TEMPORARY_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 +729,7 @@ 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 +760,10 @@ 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 +774,9 @@ 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 +921,63 @@ 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;
+}
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