/* 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; }