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- /* Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- /*
- * chunk_filter.c --- HTTP/1.1 chunked transfer encoding filter.
- */
- #include "apr_strings.h"
- #include "apr_thread_proc.h" /* for RLIMIT stuff */
- #define APR_WANT_STRFUNC
- #include "apr_want.h"
- #define CORE_PRIVATE
- #include "httpd.h"
- #include "http_config.h"
- #include "http_connection.h"
- #include "http_core.h"
- #include "http_protocol.h" /* For index_of_response(). Grump. */
- #include "http_request.h"
- #include "util_filter.h"
- #include "util_ebcdic.h"
- #include "ap_mpm.h"
- #include "scoreboard.h"
- #include "mod_core.h"
- /*
- * A pointer to this is used to memorize in the filter context that a bad
- * gateway error bucket had been seen. It is used as an invented unique pointer.
- */
- static char bad_gateway_seen;
- apr_status_t ap_http_chunk_filter(ap_filter_t *f, apr_bucket_brigade *b)
- {
- #define ASCII_CRLF "\015\012"
- #define ASCII_ZERO "\060"
- conn_rec *c = f->r->connection;
- apr_bucket_brigade *more;
- apr_bucket *e;
- apr_status_t rv;
- for (more = NULL; b; b = more, more = NULL) {
- apr_off_t bytes = 0;
- apr_bucket *eos = NULL;
- apr_bucket *flush = NULL;
- /* XXX: chunk_hdr must remain at this scope since it is used in a
- * transient bucket.
- */
- char chunk_hdr[20]; /* enough space for the snprintf below */
- for (e = APR_BRIGADE_FIRST(b);
- e != APR_BRIGADE_SENTINEL(b);
- e = APR_BUCKET_NEXT(e))
- {
- if (APR_BUCKET_IS_EOS(e)) {
- /* there shouldn't be anything after the eos */
- eos = e;
- break;
- }
- if (AP_BUCKET_IS_ERROR(e)
- && (((ap_bucket_error *)(e->data))->status
- == HTTP_BAD_GATEWAY)) {
- /*
- * We had a broken backend. Memorize this in the filter
- * context.
- */
- f->ctx = &bad_gateway_seen;
- continue;
- }
- if (APR_BUCKET_IS_FLUSH(e)) {
- flush = e;
- if (e != APR_BRIGADE_LAST(b)) {
- more = apr_brigade_split(b, APR_BUCKET_NEXT(e));
- }
- break;
- }
- else if (e->length == (apr_size_t)-1) {
- /* unknown amount of data (e.g. a pipe) */
- const char *data;
- apr_size_t len;
- rv = apr_bucket_read(e, &data, &len, APR_BLOCK_READ);
- if (rv != APR_SUCCESS) {
- return rv;
- }
- if (len > 0) {
- /*
- * There may be a new next bucket representing the
- * rest of the data stream on which a read() may
- * block so we pass down what we have so far.
- */
- bytes += len;
- more = apr_brigade_split(b, APR_BUCKET_NEXT(e));
- break;
- }
- else {
- /* If there was nothing in this bucket then we can
- * safely move on to the next one without pausing
- * to pass down what we have counted up so far.
- */
- continue;
- }
- }
- else {
- bytes += e->length;
- }
- }
- /*
- * XXX: if there aren't very many bytes at this point it may
- * be a good idea to set them aside and return for more,
- * unless we haven't finished counting this brigade yet.
- */
- /* if there are content bytes, then wrap them in a chunk */
- if (bytes > 0) {
- apr_size_t hdr_len;
- /*
- * Insert the chunk header, specifying the number of bytes in
- * the chunk.
- */
- hdr_len = apr_snprintf(chunk_hdr, sizeof(chunk_hdr),
- "%" APR_UINT64_T_HEX_FMT CRLF, (apr_uint64_t)bytes);
- ap_xlate_proto_to_ascii(chunk_hdr, hdr_len);
- e = apr_bucket_transient_create(chunk_hdr, hdr_len,
- c->bucket_alloc);
- APR_BRIGADE_INSERT_HEAD(b, e);
- /*
- * Insert the end-of-chunk CRLF before an EOS or
- * FLUSH bucket, or appended to the brigade
- */
- e = apr_bucket_immortal_create(ASCII_CRLF, 2, c->bucket_alloc);
- if (eos != NULL) {
- APR_BUCKET_INSERT_BEFORE(eos, e);
- }
- else if (flush != NULL) {
- APR_BUCKET_INSERT_BEFORE(flush, e);
- }
- else {
- APR_BRIGADE_INSERT_TAIL(b, e);
- }
- }
- /* RFC 2616, Section 3.6.1
- *
- * If there is an EOS bucket, then prefix it with:
- * 1) the last-chunk marker ("0" CRLF)
- * 2) the trailer
- * 3) the end-of-chunked body CRLF
- *
- * We only do this if we have not seen an error bucket with
- * status HTTP_BAD_GATEWAY. We have memorized an
- * error bucket that we had seen in the filter context.
- * The error bucket with status HTTP_BAD_GATEWAY indicates that the
- * connection to the backend (mod_proxy) broke in the middle of the
- * response. In order to signal the client that something went wrong
- * we do not create the last-chunk marker and set c->keepalive to
- * AP_CONN_CLOSE in the core output filter.
- *
- * XXX: it would be nice to combine this with the end-of-chunk
- * marker above, but this is a bit more straight-forward for
- * now.
- */
- if (eos && !f->ctx) {
- /* XXX: (2) trailers ... does not yet exist */
- e = apr_bucket_immortal_create(ASCII_ZERO ASCII_CRLF
- /* <trailers> */
- ASCII_CRLF, 5, c->bucket_alloc);
- APR_BUCKET_INSERT_BEFORE(eos, e);
- }
- /* pass the brigade to the next filter. */
- rv = ap_pass_brigade(f->next, b);
- if (rv != APR_SUCCESS || eos != NULL) {
- return rv;
- }
- }
- return APR_SUCCESS;
- }
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