Added support for trailers in HTTP responses.

Example:

   ngx_table_elt_t  *h;

   h = ngx_list_push(&r->headers_out.trailers);
   if (h == NULL) {
       return NGX_ERROR;
   }

   ngx_str_set(&h->key, "Fun");
   ngx_str_set(&h->value, "with trailers");
   h->hash = ngx_hash_key_lc(h->key.data, h->key.len);

The code above adds "Fun: with trailers" trailer to the response.

Modules that want to emit trailers must set r->expect_trailers = 1
in header filter, otherwise they might not be emitted for HTTP/1.1
responses that aren't already chunked.

This change also adds $sent_trailer_* variables.

Signed-off-by: Piotr Sikora <piotrsikora@google.com>
This commit is contained in:
Piotr Sikora 2017-03-24 03:37:34 -07:00
parent fa0992ed29
commit cfdce50657
5 changed files with 160 additions and 30 deletions

View File

@ -17,6 +17,8 @@ typedef struct {
static ngx_int_t ngx_http_chunked_filter_init(ngx_conf_t *cf);
static ngx_chain_t *ngx_http_chunked_create_trailers(ngx_http_request_t *r,
ngx_http_chunked_filter_ctx_t *ctx);
static ngx_http_module_t ngx_http_chunked_filter_module_ctx = {
@ -69,27 +71,29 @@ ngx_http_chunked_header_filter(ngx_http_request_t *r)
return ngx_http_next_header_filter(r);
}
if (r->headers_out.content_length_n == -1) {
if (r->http_version < NGX_HTTP_VERSION_11) {
r->keepalive = 0;
if (r->headers_out.content_length_n == -1
|| r->expect_trailers)
{
clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
} else {
clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
if (clcf->chunked_transfer_encoding) {
r->chunked = 1;
ctx = ngx_pcalloc(r->pool,
sizeof(ngx_http_chunked_filter_ctx_t));
if (ctx == NULL) {
return NGX_ERROR;
}
ngx_http_set_ctx(r, ctx, ngx_http_chunked_filter_module);
} else {
r->keepalive = 0;
if (r->http_version >= NGX_HTTP_VERSION_11
&& clcf->chunked_transfer_encoding)
{
if (r->expect_trailers) {
ngx_http_clear_content_length(r);
}
r->chunked = 1;
ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_filter_ctx_t));
if (ctx == NULL) {
return NGX_ERROR;
}
ngx_http_set_ctx(r, ctx, ngx_http_chunked_filter_module);
} else if (r->headers_out.content_length_n == -1) {
r->keepalive = 0;
}
}
@ -179,26 +183,17 @@ ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
}
if (cl->buf->last_buf) {
tl = ngx_chain_get_free_buf(r->pool, &ctx->free);
tl = ngx_http_chunked_create_trailers(r, ctx);
if (tl == NULL) {
return NGX_ERROR;
}
b = tl->buf;
b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module;
b->temporary = 0;
b->memory = 1;
b->last_buf = 1;
b->pos = (u_char *) CRLF "0" CRLF CRLF;
b->last = b->pos + 7;
cl->buf->last_buf = 0;
*ll = tl;
if (size == 0) {
b->pos += 2;
tl->buf->pos += 2;
}
} else if (size > 0) {
@ -230,6 +225,109 @@ ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
}
static ngx_chain_t *
ngx_http_chunked_create_trailers(ngx_http_request_t *r,
ngx_http_chunked_filter_ctx_t *ctx)
{
size_t len;
ngx_buf_t *b;
ngx_uint_t i;
ngx_chain_t *cl;
ngx_list_part_t *part;
ngx_table_elt_t *header;
len = 0;
part = &r->headers_out.trailers.part;
header = part->elts;
for (i = 0; /* void */; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
header = part->elts;
i = 0;
}
if (header[i].hash == 0) {
continue;
}
len += header[i].key.len + sizeof(": ") - 1
+ header[i].value.len + sizeof(CRLF) - 1;
}
cl = ngx_chain_get_free_buf(r->pool, &ctx->free);
if (cl == NULL) {
return NULL;
}
b = cl->buf;
b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module;
b->temporary = 0;
b->memory = 1;
b->last_buf = 1;
if (len == 0) {
b->pos = (u_char *) CRLF "0" CRLF CRLF;
b->last = b->pos + sizeof(CRLF "0" CRLF CRLF) - 1;
return cl;
}
len += sizeof(CRLF "0" CRLF CRLF) - 1;
b->pos = ngx_palloc(r->pool, len);
if (b->pos == NULL) {
return NULL;
}
b->last = b->pos;
*b->last++ = CR; *b->last++ = LF;
*b->last++ = '0';
*b->last++ = CR; *b->last++ = LF;
part = &r->headers_out.trailers.part;
header = part->elts;
for (i = 0; /* void */; i++) {
if (i >= part->nelts) {
if (part->next == NULL) {
break;
}
part = part->next;
header = part->elts;
i = 0;
}
if (header[i].hash == 0) {
continue;
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http trailer: \"%V: %V\"",
&header[i].key, &header[i].value);
b->last = ngx_copy(b->last, header[i].key.data, header[i].key.len);
*b->last++ = ':'; *b->last++ = ' ';
b->last = ngx_copy(b->last, header[i].value.data, header[i].value.len);
*b->last++ = CR; *b->last++ = LF;
}
*b->last++ = CR; *b->last++ = LF;
return cl;
}
static ngx_int_t
ngx_http_chunked_filter_init(ngx_conf_t *cf)
{

View File

@ -2485,6 +2485,13 @@ ngx_http_subrequest(ngx_http_request_t *r,
return NGX_ERROR;
}
if (ngx_list_init(&sr->headers_out.trailers, r->pool, 4,
sizeof(ngx_table_elt_t))
!= NGX_OK)
{
return NGX_ERROR;
}
cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
sr->main_conf = cscf->ctx->main_conf;
sr->srv_conf = cscf->ctx->srv_conf;

View File

@ -562,6 +562,14 @@ ngx_http_create_request(ngx_connection_t *c)
return NULL;
}
if (ngx_list_init(&r->headers_out.trailers, r->pool, 4,
sizeof(ngx_table_elt_t))
!= NGX_OK)
{
ngx_destroy_pool(r->pool);
return NULL;
}
r->ctx = ngx_pcalloc(r->pool, sizeof(void *) * ngx_http_max_module);
if (r->ctx == NULL) {
ngx_destroy_pool(r->pool);

View File

@ -252,6 +252,7 @@ typedef struct {
typedef struct {
ngx_list_t headers;
ngx_list_t trailers;
ngx_uint_t status;
ngx_str_t status_line;
@ -514,6 +515,7 @@ struct ngx_http_request_s {
unsigned pipeline:1;
unsigned chunked:1;
unsigned header_only:1;
unsigned expect_trailers:1;
unsigned keepalive:1;
unsigned lingering_close:1;
unsigned discard_body:1;

View File

@ -38,6 +38,8 @@ static ngx_int_t ngx_http_variable_unknown_header_in(ngx_http_request_t *r,
ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_unknown_header_out(ngx_http_request_t *r,
ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_unknown_trailer_out(ngx_http_request_t *r,
ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_request_line(ngx_http_request_t *r,
ngx_http_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_http_variable_cookie(ngx_http_request_t *r,
@ -365,6 +367,9 @@ static ngx_http_variable_t ngx_http_core_variables[] = {
{ ngx_string("sent_http_"), NULL, ngx_http_variable_unknown_header_out,
0, NGX_HTTP_VAR_PREFIX, 0 },
{ ngx_string("sent_trailer_"), NULL, ngx_http_variable_unknown_trailer_out,
0, NGX_HTTP_VAR_PREFIX, 0 },
{ ngx_string("cookie_"), NULL, ngx_http_variable_cookie,
0, NGX_HTTP_VAR_PREFIX, 0 },
@ -934,6 +939,16 @@ ngx_http_variable_unknown_header_out(ngx_http_request_t *r,
}
static ngx_int_t
ngx_http_variable_unknown_trailer_out(ngx_http_request_t *r,
ngx_http_variable_value_t *v, uintptr_t data)
{
return ngx_http_variable_unknown_header(v, (ngx_str_t *) data,
&r->headers_out.trailers.part,
sizeof("sent_trailer_") - 1);
}
ngx_int_t
ngx_http_variable_unknown_header(ngx_http_variable_value_t *v, ngx_str_t *var,
ngx_list_part_t *part, size_t prefix)