| /* 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. |
| */ |
| |
| /* |
| * mod_data.c --- Turn the response into an rfc2397 data URL, suitable for |
| * displaying as inline content on a page. |
| */ |
| |
| #include "apr.h" |
| #include "apr_strings.h" |
| #include "apr_buckets.h" |
| #include "apr_base64.h" |
| #include "apr_lib.h" |
| |
| #include "ap_config.h" |
| #include "util_filter.h" |
| #include "httpd.h" |
| #include "http_config.h" |
| #include "http_log.h" |
| #include "http_request.h" |
| #include "http_protocol.h" |
| |
| #define DATA_FILTER "DATA" |
| |
| module AP_MODULE_DECLARE_DATA data_module; |
| |
| typedef struct data_ctx |
| { |
| unsigned char overflow[3]; |
| int count; |
| apr_bucket_brigade *bb; |
| } data_ctx; |
| |
| /** |
| * Create a data URL as follows: |
| * |
| * data:[<mime-type>;][charset=<charset>;]base64,<payload> |
| * |
| * Where: |
| * |
| * mime-type: The mime type of the original response. |
| * charset: The optional character set corresponding to the mime type. |
| * payload: A base64 version of the response body. |
| * |
| * The content type of the response is set to text/plain. |
| * |
| * The Content-Length header, if present, is updated with the new content |
| * length based on the increase in size expected from the base64 conversion. |
| * If the Content-Length header is too large to fit into an int, we remove |
| * the Content-Length header instead. |
| */ |
| static apr_status_t data_out_filter(ap_filter_t *f, apr_bucket_brigade *bb) |
| { |
| apr_bucket *e, *ee; |
| request_rec *r = f->r; |
| data_ctx *ctx = f->ctx; |
| apr_status_t rv = APR_SUCCESS; |
| |
| /* first time in? create a context */ |
| if (!ctx) { |
| char *type; |
| char *charset = NULL; |
| char *end; |
| const char *content_length; |
| |
| /* base64-ing won't work on subrequests, it would be nice if |
| * it did. Within subrequests, we have no EOS to check for, |
| * so we don't know when to flush the tail to the network. |
| */ |
| if (!ap_is_initial_req(f->r)) { |
| ap_remove_output_filter(f); |
| return ap_pass_brigade(f->next, bb); |
| } |
| |
| ctx = f->ctx = apr_pcalloc(r->pool, sizeof(*ctx)); |
| ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc); |
| |
| type = apr_pstrdup(r->pool, r->content_type); |
| if (type) { |
| charset = strchr(type, ' '); |
| if (charset) { |
| *charset++ = 0; |
| end = strchr(charset, ' '); |
| if (end) { |
| *end++ = 0; |
| } |
| } |
| } |
| |
| apr_brigade_printf(ctx->bb, NULL, NULL, "data:%s%s;base64,", |
| type ? type : "", charset ? charset : ""); |
| |
| content_length = apr_table_get(r->headers_out, "Content-Length"); |
| if (content_length) { |
| apr_off_t len, clen; |
| apr_brigade_length(ctx->bb, 1, &len); |
| if (ap_parse_strict_length(&clen, content_length) |
| && clen < APR_INT32_MAX) { |
| ap_set_content_length(r, len + |
| apr_base64_encode_len((int)clen) - 1); |
| } |
| else { |
| apr_table_unset(r->headers_out, "Content-Length"); |
| } |
| } |
| |
| ap_set_content_type(r, "text/plain"); |
| |
| } |
| |
| /* Do nothing if asked to filter nothing. */ |
| if (APR_BRIGADE_EMPTY(bb)) { |
| return ap_pass_brigade(f->next, bb); |
| } |
| |
| while (APR_SUCCESS == rv && !APR_BRIGADE_EMPTY(bb)) { |
| const char *data; |
| apr_size_t size; |
| apr_size_t tail; |
| apr_size_t len; |
| /* buffer big enough for 8000 encoded bytes (6000 raw bytes) and terminator */ |
| char buffer[APR_BUCKET_BUFF_SIZE + 1]; |
| char encoded[((sizeof(ctx->overflow)) / 3) * 4 + 1]; |
| |
| e = APR_BRIGADE_FIRST(bb); |
| |
| /* EOS means we are done. */ |
| if (APR_BUCKET_IS_EOS(e)) { |
| |
| /* write away the tail */ |
| if (ctx->count) { |
| len = apr_base64_encode_binary(encoded, ctx->overflow, |
| ctx->count); |
| apr_brigade_write(ctx->bb, NULL, NULL, encoded, len - 1); |
| ctx->count = 0; |
| } |
| |
| /* pass the EOS across */ |
| APR_BUCKET_REMOVE(e); |
| APR_BRIGADE_INSERT_TAIL(ctx->bb, e); |
| |
| /* pass what we have down the chain */ |
| ap_remove_output_filter(f); |
| rv = ap_pass_brigade(f->next, ctx->bb); |
| |
| /* pass any stray buckets after the EOS down the stack */ |
| if ((APR_SUCCESS == rv) && (!APR_BRIGADE_EMPTY(bb))) { |
| rv = ap_pass_brigade(f->next, bb); |
| } |
| continue; |
| } |
| |
| /* flush what we can, we can't flush the tail until EOS */ |
| if (APR_BUCKET_IS_FLUSH(e)) { |
| |
| /* pass the flush bucket across */ |
| APR_BUCKET_REMOVE(e); |
| APR_BRIGADE_INSERT_TAIL(ctx->bb, e); |
| |
| /* pass what we have down the chain */ |
| rv = ap_pass_brigade(f->next, ctx->bb); |
| continue; |
| } |
| |
| /* metadata buckets are preserved as is */ |
| if (APR_BUCKET_IS_METADATA(e)) { |
| /* |
| * Remove meta data bucket from old brigade and insert into the |
| * new. |
| */ |
| APR_BUCKET_REMOVE(e); |
| APR_BRIGADE_INSERT_TAIL(ctx->bb, e); |
| continue; |
| } |
| |
| /* make sure we don't read more than 6000 bytes at a time */ |
| apr_brigade_partition(bb, (APR_BUCKET_BUFF_SIZE / 4 * 3), &ee); |
| |
| /* size will never be more than 6000 bytes */ |
| if (APR_SUCCESS == (rv = apr_bucket_read(e, &data, &size, |
| APR_BLOCK_READ))) { |
| |
| /* fill up and write out our overflow buffer if partially used */ |
| while (size && ctx->count && ctx->count < sizeof(ctx->overflow)) { |
| ctx->overflow[ctx->count++] = *data++; |
| size--; |
| } |
| if (ctx->count == sizeof(ctx->overflow)) { |
| len = apr_base64_encode_binary(encoded, ctx->overflow, |
| sizeof(ctx->overflow)); |
| apr_brigade_write(ctx->bb, NULL, NULL, encoded, len - 1); |
| ctx->count = 0; |
| } |
| |
| /* write the main base64 chunk */ |
| tail = size % sizeof(ctx->overflow); |
| size -= tail; |
| if (size) { |
| len = apr_base64_encode_binary(buffer, |
| (const unsigned char *) data, size); |
| apr_brigade_write(ctx->bb, NULL, NULL, buffer, len - 1); |
| } |
| |
| /* save away any tail in the overflow buffer */ |
| if (tail) { |
| memcpy(ctx->overflow, data + size, tail); |
| ctx->count += tail; |
| } |
| |
| apr_bucket_delete(e); |
| |
| /* pass what we have down the chain */ |
| rv = ap_pass_brigade(f->next, ctx->bb); |
| if (rv) { |
| /* should break out of the loop, since our write to the client |
| * failed in some way. */ |
| continue; |
| } |
| |
| } |
| |
| } |
| |
| return rv; |
| |
| } |
| |
| static const command_rec data_cmds[] = { { NULL } }; |
| |
| static void register_hooks(apr_pool_t *p) |
| { |
| ap_register_output_filter(DATA_FILTER, data_out_filter, NULL, |
| AP_FTYPE_RESOURCE); |
| } |
| AP_DECLARE_MODULE(data) = { STANDARD20_MODULE_STUFF, |
| NULL, /* create per-directory config structure */ |
| NULL, /* merge per-directory config structures */ |
| NULL, /* create per-server config structure */ |
| NULL, /* merge per-server config structures */ |
| data_cmds, /* command apr_table_t */ |
| register_hooks /* register hooks */ |
| }; |
