static int send_headers(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream)
{
h2o_timestamp_t ts;
h2o_get_timestamp(conn->super.ctx, &stream->req.pool, &ts);
/* cancel push with an error response */
if (h2o_http2_stream_is_push(stream->stream_id)) {
if (400 <= stream->req.res.status)
goto CancelPush;
if (stream->cache_digests != NULL) {
ssize_t etag_index = h2o_find_header(&stream->req.headers, H2O_TOKEN_ETAG, -1);
if (etag_index != -1) {
h2o_iovec_t url = h2o_concat(&stream->req.pool, stream->req.input.scheme->name, h2o_iovec_init(H2O_STRLIT("://")),
stream->req.input.authority, stream->req.input.path);
h2o_iovec_t *etag = &stream->req.headers.entries[etag_index].value;
if (h2o_cache_digests_lookup_by_url_and_etag(stream->cache_digests, url.base, url.len, etag->base, etag->len) ==
H2O_CACHE_DIGESTS_STATE_FRESH)
goto CancelPush;
}
}
}
/* reset casper cookie in case cache-digests exist */
if (stream->cache_digests != NULL && stream->req.hostconf->http2.casper.capacity_bits != 0) {
h2o_add_header(&stream->req.pool, &stream->req.res.headers, H2O_TOKEN_SET_COOKIE,
H2O_STRLIT("h2o_casper=; Path=/; Expires=Sat, 01 Jan 2000 00:00:00 GMT"));
}
/* CASPER */
if (conn->casper != NULL) {
/* update casper if necessary */
if (stream->req.hostconf->http2.casper.track_all_types || is_blocking_asset(&stream->req)) {
if (h2o_http2_casper_lookup(conn->casper, stream->req.path.base, stream->req.path.len, 1)) {
/* cancel if the pushed resource is already marked as cached */
if (h2o_http2_stream_is_push(stream->stream_id))
goto CancelPush;
}
}
if (stream->cache_digests != NULL)
goto SkipCookie;
/* browsers might ignore push responses, or they may process the responses in a different order than they were pushed.
* Therefore H2O tries to include casper cookie only in the last stream that may be received by the client, or when the
* value become stable; see also: https://github.com/h2o/h2o/issues/421
*/
if (h2o_http2_stream_is_push(stream->stream_id)) {
if (!(conn->num_streams.pull.open == 0 && (conn->num_streams.push.half_closed - conn->num_streams.push.send_body) == 1))
goto SkipCookie;
} else {
if (conn->num_streams.push.half_closed - conn->num_streams.push.send_body != 0)
goto SkipCookie;
}
h2o_iovec_t cookie = h2o_http2_casper_get_cookie(conn->casper);
h2o_add_header(&stream->req.pool, &stream->req.res.headers, H2O_TOKEN_SET_COOKIE, cookie.base, cookie.len);
SkipCookie:;
}
if (h2o_http2_stream_is_push(stream->stream_id)) {
/* for push, send the push promise */
if (!stream->push.promise_sent)
h2o_http2_stream_send_push_promise(conn, stream);
/* send ASAP if it is a blocking asset (even in case of Firefox we can't wait 1RTT for it to reprioritize the asset) */
if (is_blocking_asset(&stream->req))
h2o_http2_scheduler_rebind(&stream->_refs.scheduler, &conn->scheduler, 257, 0);
} else {
/* raise the priority of asset files that block rendering to highest if the user-agent is _not_ using dependency-based
* prioritization (e.g. that of Firefox)
*/
if (conn->num_streams.priority.open == 0 && stream->req.hostconf->http2.reprioritize_blocking_assets &&
h2o_http2_scheduler_get_parent(&stream->_refs.scheduler) == &conn->scheduler && is_blocking_asset(&stream->req))
h2o_http2_scheduler_rebind(&stream->_refs.scheduler, &conn->scheduler, 257, 0);
}
/* send HEADERS, as well as start sending body */
if (h2o_http2_stream_is_push(stream->stream_id))
h2o_add_header_by_str(&stream->req.pool, &stream->req.res.headers, H2O_STRLIT("x-http2-push"), 0, H2O_STRLIT("pushed"));
h2o_hpack_flatten_response(&conn->_write.buf, &conn->_output_header_table, stream->stream_id,
conn->peer_settings.max_frame_size, &stream->req.res, &ts, &conn->super.ctx->globalconf->server_name,
stream->req.res.content_length);
h2o_http2_conn_request_write(conn);
h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_SEND_BODY);
return 0;
CancelPush:
h2o_add_header_by_str(&stream->req.pool, &stream->req.res.headers, H2O_STRLIT("x-http2-push"), 0, H2O_STRLIT("cancelled"));
h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_END_STREAM);
h2o_linklist_insert(&conn->_write.streams_to_proceed, &stream->_refs.link);
if (stream->push.promise_sent) {
#ifndef _MSC_VER
h2o_http2_encode_rst_stream_frame(&conn->_write.buf, stream->stream_id, -H2O_HTTP2_ERROR_INTERNAL);
#else
h2o_http2_encode_rst_stream_frame(&conn->_write.buf, stream->stream_id, H2O_HTTP2_ERROR_INTERNAL);
#endif
h2o_http2_conn_request_write(conn);
}
return -1;
}
static int send_headers(h2o_http2_conn_t *conn, h2o_http2_stream_t *stream)
{
h2o_timestamp_t ts;
size_t num_casper_entries_before_push = 0;
h2o_get_timestamp(conn->super.ctx, &stream->req.pool, &ts);
/* cancel push with an error response */
if (h2o_http2_stream_is_push(stream->stream_id)) {
if (400 <= stream->req.res.status)
goto CancelPush;
h2o_add_header_by_str(&stream->req.pool, &stream->req.res.headers, H2O_STRLIT("x-http2-pushed"), 0, H2O_STRLIT("1"));
}
if (stream->req.hostconf->http2.casper.capacity_bits != 0) {
/* extract the client-side cache fingerprint */
if (conn->casper == NULL)
h2o_http2_conn_init_casper(conn, stream->req.hostconf->http2.casper.capacity_bits);
size_t header_index = -1;
while ((header_index = h2o_find_header(&stream->req.headers, H2O_TOKEN_COOKIE, header_index)) != -1) {
h2o_header_t *header = stream->req.headers.entries + header_index;
h2o_http2_casper_consume_cookie(conn->casper, header->value.base, header->value.len);
}
num_casper_entries_before_push = h2o_http2_casper_num_entries(conn->casper);
/* update casper if necessary */
if (stream->req.hostconf->http2.casper.track_all_types || is_blocking_asset(&stream->req)) {
ssize_t etag_index = h2o_find_header(&stream->req.headers, H2O_TOKEN_ETAG, -1);
h2o_iovec_t etag = etag_index != -1 ? stream->req.headers.entries[etag_index].value : (h2o_iovec_t){};
if (h2o_http2_casper_lookup(conn->casper, stream->req.path.base, stream->req.path.len, etag.base, etag.len, 1)) {
/* cancel if the pushed resource is already marked as cached */
if (h2o_http2_stream_is_push(stream->stream_id))
goto CancelPush;
}
}
}
if (h2o_http2_stream_is_push(stream->stream_id)) {
/* for push, send the push promise */
if (!stream->push.promise_sent)
h2o_http2_stream_send_push_promise(conn, stream);
/* send ASAP if it is a blocking asset (even in case of Firefox we can't wait 1RTT for it to reprioritize the asset) */
if (is_blocking_asset(&stream->req))
h2o_http2_scheduler_rebind(&stream->_refs.scheduler, &conn->scheduler, 257, 0);
} else {
/* for pull, push things requested, as well as send the casper cookie if modified */
if (conn->peer_settings.enable_push) {
size_t i;
for (i = 0; i != stream->req.http2_push_paths.size; ++i)
h2o_http2_conn_push_path(conn, stream->req.http2_push_paths.entries[i], stream);
/* send casper cookie if it has been altered (due to the __stream itself__ or by some of the pushes) */
if (conn->casper != NULL && num_casper_entries_before_push != h2o_http2_casper_num_entries(conn->casper)) {
h2o_iovec_t cookie = h2o_http2_casper_build_cookie(conn->casper, &stream->req.pool);
h2o_add_header(&stream->req.pool, &stream->req.res.headers, H2O_TOKEN_SET_COOKIE, cookie.base, cookie.len);
}
}
/* raise the priority of asset files that block rendering to highest if the user-agent is _not_ using dependency-based
* prioritization (e.g. that of Firefox)
*/
if (conn->num_streams.open_priority == 0 && stream->req.hostconf->http2.reprioritize_blocking_assets &&
h2o_http2_scheduler_get_parent(&stream->_refs.scheduler) == &conn->scheduler && is_blocking_asset(&stream->req))
h2o_http2_scheduler_rebind(&stream->_refs.scheduler, &conn->scheduler, 257, 0);
}
/* send HEADERS, as well as start sending body */
h2o_hpack_flatten_response(&conn->_write.buf, &conn->_output_header_table, stream->stream_id,
conn->peer_settings.max_frame_size, &stream->req.res, &ts,
&conn->super.ctx->globalconf->server_name);
h2o_http2_conn_request_write(conn);
h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_SEND_BODY);
return 0;
CancelPush:
h2o_http2_stream_set_state(conn, stream, H2O_HTTP2_STREAM_STATE_END_STREAM);
h2o_linklist_insert(&conn->_write.streams_to_proceed, &stream->_refs.link);
if (stream->push.promise_sent) {
h2o_http2_encode_rst_stream_frame(&conn->_write.buf, stream->stream_id, H2O_HTTP2_ERROR_INTERNAL);
h2o_http2_conn_request_write(conn);
}
return -1;
}