/* 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_deflate.c: Perform deflate content-encoding on the fly * * Written by Ian Holsman, Justin Erenkrantz, and Nick Kew */ /* * Portions of this software are based upon zlib code by Jean-loup Gailly * (zlib functions gz_open and gzwrite, check_header) */ /* zlib flags */ #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ #define HEAD_CRC 0x02 /* bit 1 set: header CRC present */ #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ #define COMMENT 0x10 /* bit 4 set: file comment present */ #define RESERVED 0xE0 /* bits 5..7: reserved */ #include "httpd.h" #include "http_config.h" #include "http_log.h" #include "apr_lib.h" #include "apr_strings.h" #include "apr_general.h" #include "util_filter.h" #include "apr_buckets.h" #include "http_request.h" #define APR_WANT_STRFUNC #include "apr_want.h" #include "zlib.h" static const char deflateFilterName[] = "DEFLATE"; module AP_MODULE_DECLARE_DATA deflate_module; typedef struct deflate_filter_config_t { int windowSize; int memlevel; int compressionlevel; apr_size_t bufferSize; char *note_ratio_name; char *note_input_name; char *note_output_name; } deflate_filter_config; /* RFC 1952 Section 2.3 defines the gzip header: * * +---+---+---+---+---+---+---+---+---+---+ * |ID1|ID2|CM |FLG| MTIME |XFL|OS | * +---+---+---+---+---+---+---+---+---+---+ */ static const char gzip_header[10] = { '\037', '\213', Z_DEFLATED, 0, 0, 0, 0, 0, /* mtime */ 0, 0x03 /* Unix OS_CODE */ }; /* magic header */ static const char deflate_magic[2] = { '\037', '\213' }; /* windowsize is negative to suppress Zlib header */ #define DEFAULT_COMPRESSION Z_DEFAULT_COMPRESSION #define DEFAULT_WINDOWSIZE -15 #define DEFAULT_MEMLEVEL 9 #define DEFAULT_BUFFERSIZE 8096 /* Check whether a request is gzipped, so we can un-gzip it. * If a request has multiple encodings, we need the gzip * to be the outermost non-identity encoding. */ static int check_gzip(request_rec *r, apr_table_t *hdrs1, apr_table_t *hdrs2) { int found = 0; apr_table_t *hdrs = hdrs1; const char *encoding = apr_table_get(hdrs, "Content-Encoding"); if (!encoding && (hdrs2 != NULL)) { /* the output filter has two tables and a content_encoding to check */ encoding = apr_table_get(hdrs2, "Content-Encoding"); hdrs = hdrs2; if (!encoding) { encoding = r->content_encoding; hdrs = NULL; } } if (encoding && *encoding) { /* check the usual/simple case first */ if (!strcasecmp(encoding, "gzip") || !strcasecmp(encoding, "x-gzip")) { found = 1; if (hdrs) { apr_table_unset(hdrs, "Content-Encoding"); } else { r->content_encoding = NULL; } } else if (ap_strchr_c(encoding, ',') != NULL) { /* If the outermost encoding isn't gzip, there's nowt * we can do. So only check the last non-identity token */ char *new_encoding = apr_pstrdup(r->pool, encoding); char *ptr; for(;;) { char *token = ap_strrchr(new_encoding, ','); if (!token) { /* gzip:identity or other:identity */ if (!strcasecmp(new_encoding, "gzip") || !strcasecmp(new_encoding, "x-gzip")) { found = 1; if (hdrs) { apr_table_unset(hdrs, "Content-Encoding"); } else { r->content_encoding = NULL; } } break; /* seen all tokens */ } for (ptr=token+1; apr_isspace(*ptr); ++ptr); if (!strcasecmp(ptr, "gzip") || !strcasecmp(ptr, "x-gzip")) { *token = '\0'; if (hdrs) { apr_table_setn(hdrs, "Content-Encoding", new_encoding); } else { r->content_encoding = new_encoding; } found = 1; } else if (!ptr[0] || !strcasecmp(ptr, "identity")) { *token = '\0'; continue; /* strip the token and find the next one */ } break; /* found a non-identity token */ } } } return found; } /* Outputs a long in LSB order to the given file * only the bottom 4 bits are required for the deflate file format. */ static void putLong(unsigned char *string, unsigned long x) { string[0] = (unsigned char)(x & 0xff); string[1] = (unsigned char)((x & 0xff00) >> 8); string[2] = (unsigned char)((x & 0xff0000) >> 16); string[3] = (unsigned char)((x & 0xff000000) >> 24); } /* Inputs a string and returns a long. */ static unsigned long getLong(unsigned char *string) { return ((unsigned long)string[0]) | (((unsigned long)string[1]) << 8) | (((unsigned long)string[2]) << 16) | (((unsigned long)string[3]) << 24); } static void *create_deflate_server_config(apr_pool_t *p, server_rec *s) { deflate_filter_config *c = apr_pcalloc(p, sizeof *c); c->memlevel = DEFAULT_MEMLEVEL; c->windowSize = DEFAULT_WINDOWSIZE; c->bufferSize = DEFAULT_BUFFERSIZE; c->compressionlevel = DEFAULT_COMPRESSION; return c; } static const char *deflate_set_window_size(cmd_parms *cmd, void *dummy, const char *arg) { deflate_filter_config *c = ap_get_module_config(cmd->server->module_config, &deflate_module); int i; i = atoi(arg); if (i < 1 || i > 15) return "DeflateWindowSize must be between 1 and 15"; c->windowSize = i * -1; return NULL; } static const char *deflate_set_buffer_size(cmd_parms *cmd, void *dummy, const char *arg) { deflate_filter_config *c = ap_get_module_config(cmd->server->module_config, &deflate_module); int n = atoi(arg); if (n <= 0) { return "DeflateBufferSize should be positive"; } c->bufferSize = (apr_size_t)n; return NULL; } static const char *deflate_set_note(cmd_parms *cmd, void *dummy, const char *arg1, const char *arg2) { deflate_filter_config *c = ap_get_module_config(cmd->server->module_config, &deflate_module); if (arg2 == NULL) { c->note_ratio_name = apr_pstrdup(cmd->pool, arg1); } else if (!strcasecmp(arg1, "ratio")) { c->note_ratio_name = apr_pstrdup(cmd->pool, arg2); } else if (!strcasecmp(arg1, "input")) { c->note_input_name = apr_pstrdup(cmd->pool, arg2); } else if (!strcasecmp(arg1, "output")) { c->note_output_name = apr_pstrdup(cmd->pool, arg2); } else { return apr_psprintf(cmd->pool, "Unknown note type %s", arg1); } return NULL; } static const char *deflate_set_memlevel(cmd_parms *cmd, void *dummy, const char *arg) { deflate_filter_config *c = ap_get_module_config(cmd->server->module_config, &deflate_module); int i; i = atoi(arg); if (i < 1 || i > 9) return "DeflateMemLevel must be between 1 and 9"; c->memlevel = i; return NULL; } static const char *deflate_set_compressionlevel(cmd_parms *cmd, void *dummy, const char *arg) { deflate_filter_config *c = ap_get_module_config(cmd->server->module_config, &deflate_module); int i; i = atoi(arg); if (i < 1 || i > 9) return "Compression Level must be between 1 and 9"; c->compressionlevel = i; return NULL; } typedef struct deflate_ctx_t { z_stream stream; unsigned char *buffer; unsigned long crc; apr_bucket_brigade *bb, *proc_bb; int (*libz_end_func)(z_streamp); unsigned char *validation_buffer; apr_size_t validation_buffer_length; int inflate_init; } deflate_ctx; /* Number of validation bytes (CRC and length) after the compressed data */ #define VALIDATION_SIZE 8 /* Do not update ctx->crc, see comment in flush_libz_buffer */ #define NO_UPDATE_CRC 0 /* Do update ctx->crc, see comment in flush_libz_buffer */ #define UPDATE_CRC 1 static int flush_libz_buffer(deflate_ctx *ctx, deflate_filter_config *c, struct apr_bucket_alloc_t *bucket_alloc, int (*libz_func)(z_streamp, int), int flush, int crc) { int zRC = Z_OK; int done = 0; unsigned int deflate_len; apr_bucket *b; for (;;) { deflate_len = c->bufferSize - ctx->stream.avail_out; if (deflate_len != 0) { /* * Do we need to update ctx->crc? Usually this is the case for * inflate action where we need to do a crc on the output, whereas * in the deflate case we need to do a crc on the input */ if (crc) { ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, deflate_len); } b = apr_bucket_heap_create((char *)ctx->buffer, deflate_len, NULL, bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->bb, b); ctx->stream.next_out = ctx->buffer; ctx->stream.avail_out = c->bufferSize; } if (done) break; zRC = libz_func(&ctx->stream, flush); /* * We can ignore Z_BUF_ERROR because: * When we call libz_func we can assume that * * - avail_in is zero (due to the surrounding code that calls * flush_libz_buffer) * - avail_out is non zero due to our actions some lines above * * So the only reason for Z_BUF_ERROR is that the internal libz * buffers are now empty and thus we called libz_func one time * too often. This does not hurt. It simply says that we are done. */ if (zRC == Z_BUF_ERROR) { zRC = Z_OK; break; } done = (ctx->stream.avail_out != 0 || zRC == Z_STREAM_END); if (zRC != Z_OK && zRC != Z_STREAM_END) break; } return zRC; } static apr_status_t deflate_ctx_cleanup(void *data) { deflate_ctx *ctx = (deflate_ctx *)data; if (ctx) ctx->libz_end_func(&ctx->stream); return APR_SUCCESS; } /* PR 39727: we're screwing up our clients if we leave a strong ETag * header while transforming content. Henrik Nordstrom suggests * appending ";gzip". * * Pending a more thorough review of our Etag handling, let's just * implement his suggestion. It fixes the bug, or at least turns it * from a showstopper to an inefficiency. And it breaks nothing that * wasn't already broken. */ static void deflate_check_etag(request_rec *r, const char *transform) { const char *etag = apr_table_get(r->headers_out, "ETag"); if (etag && (((etag[0] != 'W') && (etag[0] !='w')) || (etag[1] != '/'))) { apr_table_set(r->headers_out, "ETag", apr_pstrcat(r->pool, etag, "-", transform, NULL)); } } static apr_status_t deflate_out_filter(ap_filter_t *f, apr_bucket_brigade *bb) { apr_bucket *e; request_rec *r = f->r; deflate_ctx *ctx = f->ctx; int zRC; deflate_filter_config *c; /* Do nothing if asked to filter nothing. */ if (APR_BRIGADE_EMPTY(bb)) { return ap_pass_brigade(f->next, bb); } c = ap_get_module_config(r->server->module_config, &deflate_module); /* If we don't have a context, we need to ensure that it is okay to send * the deflated content. If we have a context, that means we've done * this before and we liked it. * This could be not so nice if we always fail. But, if we succeed, * we're in better shape. */ if (!ctx) { char *token; const char *encoding; /* only work on main request/no subrequests */ if (r->main != NULL) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* some browsers might have problems, so set no-gzip * (with browsermatch) for them */ if (apr_table_get(r->subprocess_env, "no-gzip")) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* We can't operate on Content-Ranges */ if (apr_table_get(r->headers_out, "Content-Range") != NULL) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* Some browsers might have problems with content types * other than text/html, so set gzip-only-text/html * (with browsermatch) for them */ if (r->content_type == NULL || strncmp(r->content_type, "text/html", 9)) { const char *env_value = apr_table_get(r->subprocess_env, "gzip-only-text/html"); if ( env_value && (strcmp(env_value,"1") == 0) ) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } } /* Let's see what our current Content-Encoding is. * If it's already encoded, don't compress again. * (We could, but let's not.) */ encoding = apr_table_get(r->headers_out, "Content-Encoding"); if (encoding) { const char *err_enc; err_enc = apr_table_get(r->err_headers_out, "Content-Encoding"); if (err_enc) { encoding = apr_pstrcat(r->pool, encoding, ",", err_enc, NULL); } } else { encoding = apr_table_get(r->err_headers_out, "Content-Encoding"); } if (r->content_encoding) { encoding = encoding ? apr_pstrcat(r->pool, encoding, ",", r->content_encoding, NULL) : r->content_encoding; } if (encoding) { const char *tmp = encoding; token = ap_get_token(r->pool, &tmp, 0); while (token && *token) { /* stolen from mod_negotiation: */ if (strcmp(token, "identity") && strcmp(token, "7bit") && strcmp(token, "8bit") && strcmp(token, "binary")) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* Otherwise, skip token */ if (*tmp) { ++tmp; } token = (*tmp) ? ap_get_token(r->pool, &tmp, 0) : NULL; } } /* Even if we don't accept this request based on it not having * the Accept-Encoding, we need to note that we were looking * for this header and downstream proxies should be aware of that. */ apr_table_mergen(r->headers_out, "Vary", "Accept-Encoding"); /* force-gzip will just force it out regardless if the browser * can actually do anything with it. */ if (!apr_table_get(r->subprocess_env, "force-gzip")) { const char *accepts; /* if they don't have the line, then they can't play */ accepts = apr_table_get(r->headers_in, "Accept-Encoding"); if (accepts == NULL) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } token = ap_get_token(r->pool, &accepts, 0); while (token && token[0] && strcasecmp(token, "gzip")) { /* skip parameters, XXX: ;q=foo evaluation? */ while (*accepts == ';') { ++accepts; token = ap_get_token(r->pool, &accepts, 1); } /* retrieve next token */ if (*accepts == ',') { ++accepts; } token = (*accepts) ? ap_get_token(r->pool, &accepts, 0) : NULL; } /* No acceptable token found. */ if (token == NULL || token[0] == '\0') { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } } /* For a 304 or 204 response there is no entity included in * the response and hence nothing to deflate. */ if (r->status == HTTP_NOT_MODIFIED || r->status == HTTP_NO_CONTENT) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* We're cool with filtering this. */ ctx = f->ctx = apr_pcalloc(r->pool, sizeof(*ctx)); ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc); ctx->buffer = apr_palloc(r->pool, c->bufferSize); ctx->libz_end_func = deflateEnd; zRC = deflateInit2(&ctx->stream, c->compressionlevel, Z_DEFLATED, c->windowSize, c->memlevel, Z_DEFAULT_STRATEGY); if (zRC != Z_OK) { deflateEnd(&ctx->stream); ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "unable to init Zlib: " "deflateInit2 returned %d: URL %s", zRC, r->uri); /* * Remove ourselves as it does not make sense to return: * We are not able to init libz and pass data down the chain * uncompressed. */ ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* * Register a cleanup function to ensure that we cleanup the internal * libz resources. */ apr_pool_cleanup_register(r->pool, ctx, deflate_ctx_cleanup, apr_pool_cleanup_null); /* add immortal gzip header */ e = apr_bucket_immortal_create(gzip_header, sizeof gzip_header, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->bb, e); /* If the entire Content-Encoding is "identity", we can replace it. */ if (!encoding || !strcasecmp(encoding, "identity")) { apr_table_setn(r->headers_out, "Content-Encoding", "gzip"); } else { apr_table_mergen(r->headers_out, "Content-Encoding", "gzip"); } apr_table_unset(r->headers_out, "Content-Length"); apr_table_unset(r->headers_out, "Content-MD5"); deflate_check_etag(r, "gzip"); /* initialize deflate output buffer */ ctx->stream.next_out = ctx->buffer; ctx->stream.avail_out = c->bufferSize; } while (!APR_BRIGADE_EMPTY(bb)) { const char *data; apr_bucket *b; apr_size_t len; e = APR_BRIGADE_FIRST(bb); if (APR_BUCKET_IS_EOS(e)) { char *buf; ctx->stream.avail_in = 0; /* should be zero already anyway */ /* flush the remaining data from the zlib buffers */ flush_libz_buffer(ctx, c, f->c->bucket_alloc, deflate, Z_FINISH, NO_UPDATE_CRC); buf = apr_palloc(r->pool, VALIDATION_SIZE); putLong((unsigned char *)&buf[0], ctx->crc); putLong((unsigned char *)&buf[4], ctx->stream.total_in); b = apr_bucket_pool_create(buf, VALIDATION_SIZE, r->pool, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->bb, b); ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "Zlib: Compressed %ld to %ld : URL %s", ctx->stream.total_in, ctx->stream.total_out, r->uri); /* leave notes for logging */ if (c->note_input_name) { apr_table_setn(r->notes, c->note_input_name, (ctx->stream.total_in > 0) ? apr_off_t_toa(r->pool, ctx->stream.total_in) : "-"); } if (c->note_output_name) { apr_table_setn(r->notes, c->note_output_name, (ctx->stream.total_in > 0) ? apr_off_t_toa(r->pool, ctx->stream.total_out) : "-"); } if (c->note_ratio_name) { apr_table_setn(r->notes, c->note_ratio_name, (ctx->stream.total_in > 0) ? apr_itoa(r->pool, (int)(ctx->stream.total_out * 100 / ctx->stream.total_in)) : "-"); } deflateEnd(&ctx->stream); /* No need for cleanup any longer */ apr_pool_cleanup_kill(r->pool, ctx, deflate_ctx_cleanup); /* Remove EOS from the old list, and insert into the new. */ APR_BUCKET_REMOVE(e); APR_BRIGADE_INSERT_TAIL(ctx->bb, e); /* Okay, we've seen the EOS. * Time to pass it along down the chain. */ return ap_pass_brigade(f->next, ctx->bb); } if (APR_BUCKET_IS_FLUSH(e)) { apr_status_t rv; /* flush the remaining data from the zlib buffers */ zRC = flush_libz_buffer(ctx, c, f->c->bucket_alloc, deflate, Z_SYNC_FLUSH, NO_UPDATE_CRC); if (zRC != Z_OK) { return APR_EGENERAL; } /* Remove flush bucket from old brigade anf insert into the new. */ APR_BUCKET_REMOVE(e); APR_BRIGADE_INSERT_TAIL(ctx->bb, e); rv = ap_pass_brigade(f->next, ctx->bb); if (rv != APR_SUCCESS) { return rv; } continue; } 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; } /* read */ apr_bucket_read(e, &data, &len, APR_BLOCK_READ); /* This crc32 function is from zlib. */ ctx->crc = crc32(ctx->crc, (const Bytef *)data, len); /* write */ ctx->stream.next_in = (unsigned char *)data; /* We just lost const-ness, * but we'll just have to * trust zlib */ ctx->stream.avail_in = len; while (ctx->stream.avail_in != 0) { if (ctx->stream.avail_out == 0) { apr_status_t rv; ctx->stream.next_out = ctx->buffer; len = c->bufferSize - ctx->stream.avail_out; b = apr_bucket_heap_create((char *)ctx->buffer, len, NULL, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->bb, b); ctx->stream.avail_out = c->bufferSize; /* Send what we have right now to the next filter. */ rv = ap_pass_brigade(f->next, ctx->bb); if (rv != APR_SUCCESS) { return rv; } } zRC = deflate(&(ctx->stream), Z_NO_FLUSH); if (zRC != Z_OK) { return APR_EGENERAL; } } apr_bucket_delete(e); } apr_brigade_cleanup(bb); return APR_SUCCESS; } /* This is the deflate input filter (inflates). */ static apr_status_t deflate_in_filter(ap_filter_t *f, apr_bucket_brigade *bb, ap_input_mode_t mode, apr_read_type_e block, apr_off_t readbytes) { apr_bucket *bkt; request_rec *r = f->r; deflate_ctx *ctx = f->ctx; int zRC; apr_status_t rv; deflate_filter_config *c; /* just get out of the way of things we don't want. */ if (mode != AP_MODE_READBYTES) { return ap_get_brigade(f->next, bb, mode, block, readbytes); } c = ap_get_module_config(r->server->module_config, &deflate_module); if (!ctx) { char deflate_hdr[10]; apr_size_t len; /* only work on main request/no subrequests */ if (!ap_is_initial_req(r)) { ap_remove_input_filter(f); return ap_get_brigade(f->next, bb, mode, block, readbytes); } /* We can't operate on Content-Ranges */ if (apr_table_get(r->headers_in, "Content-Range") != NULL) { ap_remove_input_filter(f); return ap_get_brigade(f->next, bb, mode, block, readbytes); } /* Check whether request body is gzipped. * * If it is, we're transforming the contents, invalidating * some request headers including Content-Encoding. * * If not, we just remove ourself. */ if (check_gzip(r, r->headers_in, NULL) == 0) { ap_remove_input_filter(f); return ap_get_brigade(f->next, bb, mode, block, readbytes); } f->ctx = ctx = apr_pcalloc(f->r->pool, sizeof(*ctx)); ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc); ctx->proc_bb = apr_brigade_create(r->pool, f->c->bucket_alloc); ctx->buffer = apr_palloc(r->pool, c->bufferSize); rv = ap_get_brigade(f->next, ctx->bb, AP_MODE_READBYTES, block, 10); if (rv != APR_SUCCESS) { return rv; } apr_table_unset(r->headers_in, "Content-Length"); apr_table_unset(r->headers_in, "Content-MD5"); len = 10; rv = apr_brigade_flatten(ctx->bb, deflate_hdr, &len); if (rv != APR_SUCCESS) { return rv; } /* We didn't get the magic bytes. */ if (len != 10 || deflate_hdr[0] != deflate_magic[0] || deflate_hdr[1] != deflate_magic[1]) { return APR_EGENERAL; } /* We can't handle flags for now. */ if (deflate_hdr[3] != 0) { return APR_EGENERAL; } zRC = inflateInit2(&ctx->stream, c->windowSize); if (zRC != Z_OK) { f->ctx = NULL; inflateEnd(&ctx->stream); ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "unable to init Zlib: " "inflateInit2 returned %d: URL %s", zRC, r->uri); ap_remove_input_filter(f); return ap_get_brigade(f->next, bb, mode, block, readbytes); } /* initialize deflate output buffer */ ctx->stream.next_out = ctx->buffer; ctx->stream.avail_out = c->bufferSize; apr_brigade_cleanup(ctx->bb); } if (APR_BRIGADE_EMPTY(ctx->proc_bb)) { rv = ap_get_brigade(f->next, ctx->bb, mode, block, readbytes); if (rv != APR_SUCCESS) { /* What about APR_EAGAIN errors? */ inflateEnd(&ctx->stream); return rv; } for (bkt = APR_BRIGADE_FIRST(ctx->bb); bkt != APR_BRIGADE_SENTINEL(ctx->bb); bkt = APR_BUCKET_NEXT(bkt)) { const char *data; apr_size_t len; /* If we actually see the EOS, that means we screwed up! */ if (APR_BUCKET_IS_EOS(bkt)) { inflateEnd(&ctx->stream); return APR_EGENERAL; } if (APR_BUCKET_IS_FLUSH(bkt)) { apr_bucket *tmp_heap; zRC = inflate(&(ctx->stream), Z_SYNC_FLUSH); if (zRC != Z_OK) { inflateEnd(&ctx->stream); return APR_EGENERAL; } ctx->stream.next_out = ctx->buffer; len = c->bufferSize - ctx->stream.avail_out; ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len); tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len, NULL, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap); ctx->stream.avail_out = c->bufferSize; /* Move everything to the returning brigade. */ APR_BUCKET_REMOVE(bkt); APR_BRIGADE_CONCAT(bb, ctx->bb); break; } /* read */ apr_bucket_read(bkt, &data, &len, APR_BLOCK_READ); /* pass through zlib inflate. */ ctx->stream.next_in = (unsigned char *)data; ctx->stream.avail_in = len; zRC = Z_OK; while (ctx->stream.avail_in != 0) { if (ctx->stream.avail_out == 0) { apr_bucket *tmp_heap; ctx->stream.next_out = ctx->buffer; len = c->bufferSize - ctx->stream.avail_out; ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len); tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len, NULL, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap); ctx->stream.avail_out = c->bufferSize; } zRC = inflate(&ctx->stream, Z_NO_FLUSH); if (zRC == Z_STREAM_END) { break; } if (zRC != Z_OK) { inflateEnd(&ctx->stream); return APR_EGENERAL; } } if (zRC == Z_STREAM_END) { apr_bucket *tmp_heap, *eos; ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "Zlib: Inflated %ld to %ld : URL %s", ctx->stream.total_in, ctx->stream.total_out, r->uri); len = c->bufferSize - ctx->stream.avail_out; ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len); tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len, NULL, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap); ctx->stream.avail_out = c->bufferSize; /* Is the remaining 8 bytes already in the avail stream? */ if (ctx->stream.avail_in >= 8) { unsigned long compCRC, compLen; compCRC = getLong(ctx->stream.next_in); if (ctx->crc != compCRC) { inflateEnd(&ctx->stream); return APR_EGENERAL; } ctx->stream.next_in += 4; compLen = getLong(ctx->stream.next_in); if (ctx->stream.total_out != compLen) { inflateEnd(&ctx->stream); return APR_EGENERAL; } } else { /* FIXME: We need to grab the 8 verification bytes * from the wire! */ inflateEnd(&ctx->stream); return APR_EGENERAL; } inflateEnd(&ctx->stream); eos = apr_bucket_eos_create(f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, eos); break; } } apr_brigade_cleanup(ctx->bb); } /* If we are about to return nothing for a 'blocking' read and we have * some data in our zlib buffer, flush it out so we can return something. */ if (block == APR_BLOCK_READ && APR_BRIGADE_EMPTY(ctx->proc_bb) && ctx->stream.avail_out < c->bufferSize) { apr_bucket *tmp_heap; apr_size_t len; ctx->stream.next_out = ctx->buffer; len = c->bufferSize - ctx->stream.avail_out; ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len); tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len, NULL, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap); ctx->stream.avail_out = c->bufferSize; } if (!APR_BRIGADE_EMPTY(ctx->proc_bb)) { apr_bucket_brigade *newbb; /* May return APR_INCOMPLETE which is fine by us. */ apr_brigade_partition(ctx->proc_bb, readbytes, &bkt); newbb = apr_brigade_split(ctx->proc_bb, bkt); APR_BRIGADE_CONCAT(bb, ctx->proc_bb); APR_BRIGADE_CONCAT(ctx->proc_bb, newbb); } return APR_SUCCESS; } /* Filter to inflate for a content-transforming proxy. */ static apr_status_t inflate_out_filter(ap_filter_t *f, apr_bucket_brigade *bb) { int zlib_method; int zlib_flags; apr_bucket *e; request_rec *r = f->r; deflate_ctx *ctx = f->ctx; int zRC; apr_status_t rv; deflate_filter_config *c; /* Do nothing if asked to filter nothing. */ if (APR_BRIGADE_EMPTY(bb)) { return ap_pass_brigade(f->next, bb); } c = ap_get_module_config(r->server->module_config, &deflate_module); if (!ctx) { /* only work on main request/no subrequests */ if (!ap_is_initial_req(r)) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* We can't operate on Content-Ranges */ if (apr_table_get(r->headers_out, "Content-Range") != NULL) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* * Let's see what our current Content-Encoding is. * Only inflate if gzipped. */ if (check_gzip(r, r->headers_out, r->err_headers_out) == 0) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* No need to inflate HEAD or 204/304 */ if (APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(bb))) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } f->ctx = ctx = apr_pcalloc(f->r->pool, sizeof(*ctx)); ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc); ctx->buffer = apr_palloc(r->pool, c->bufferSize); ctx->libz_end_func = inflateEnd; ctx->validation_buffer = NULL; ctx->validation_buffer_length = 0; zRC = inflateInit2(&ctx->stream, c->windowSize); if (zRC != Z_OK) { f->ctx = NULL; inflateEnd(&ctx->stream); ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "unable to init Zlib: " "inflateInit2 returned %d: URL %s", zRC, r->uri); /* * Remove ourselves as it does not make sense to return: * We are not able to init libz and pass data down the chain * compressed. */ ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* * Register a cleanup function to ensure that we cleanup the internal * libz resources. */ apr_pool_cleanup_register(r->pool, ctx, deflate_ctx_cleanup, apr_pool_cleanup_null); /* these are unlikely to be set anyway, but ... */ apr_table_unset(r->headers_out, "Content-Length"); apr_table_unset(r->headers_out, "Content-MD5"); deflate_check_etag(r, "gunzip"); /* initialize inflate output buffer */ ctx->stream.next_out = ctx->buffer; ctx->stream.avail_out = c->bufferSize; ctx->inflate_init = 0; } while (!APR_BRIGADE_EMPTY(bb)) { const char *data; apr_bucket *b; apr_size_t len; e = APR_BRIGADE_FIRST(bb); if (APR_BUCKET_IS_EOS(e)) { /* * We are really done now. Ensure that we never return here, even * if a second EOS bucket falls down the chain. Thus remove * ourselves. */ ap_remove_output_filter(f); /* should be zero already anyway */ ctx->stream.avail_in = 0; /* * Flush the remaining data from the zlib buffers. It is correct * to use Z_SYNC_FLUSH in this case and not Z_FINISH as in the * deflate case. In the inflate case Z_FINISH requires to have a * large enough output buffer to put ALL data in otherwise it * fails, whereas in the deflate case you can empty a filled output * buffer and call it again until no more output can be created. */ flush_libz_buffer(ctx, c, f->c->bucket_alloc, inflate, Z_SYNC_FLUSH, UPDATE_CRC); ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "Zlib: Inflated %ld to %ld : URL %s", ctx->stream.total_in, ctx->stream.total_out, r->uri); if (ctx->validation_buffer_length == VALIDATION_SIZE) { unsigned long compCRC, compLen; compCRC = getLong(ctx->validation_buffer); if (ctx->crc != compCRC) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Zlib: Checksum of inflated stream invalid"); return APR_EGENERAL; } ctx->validation_buffer += VALIDATION_SIZE / 2; compLen = getLong(ctx->validation_buffer); if (ctx->stream.total_out != compLen) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Zlib: Length of inflated stream invalid"); return APR_EGENERAL; } } else { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Zlib: Validation bytes not present"); return APR_EGENERAL; } inflateEnd(&ctx->stream); /* No need for cleanup any longer */ apr_pool_cleanup_kill(r->pool, ctx, deflate_ctx_cleanup); /* Remove EOS from the old list, and insert into the new. */ APR_BUCKET_REMOVE(e); APR_BRIGADE_INSERT_TAIL(ctx->bb, e); /* * Okay, we've seen the EOS. * Time to pass it along down the chain. */ return ap_pass_brigade(f->next, ctx->bb); } if (APR_BUCKET_IS_FLUSH(e)) { apr_status_t rv; /* flush the remaining data from the zlib buffers */ zRC = flush_libz_buffer(ctx, c, f->c->bucket_alloc, inflate, Z_SYNC_FLUSH, UPDATE_CRC); if (zRC != Z_OK) { return APR_EGENERAL; } /* Remove flush bucket from old brigade anf insert into the new. */ APR_BUCKET_REMOVE(e); APR_BRIGADE_INSERT_TAIL(ctx->bb, e); rv = ap_pass_brigade(f->next, ctx->bb); if (rv != APR_SUCCESS) { return rv; } continue; } 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; } /* read */ apr_bucket_read(e, &data, &len, APR_BLOCK_READ); /* first bucket contains zlib header */ if (!ctx->inflate_init++) { if (len < 10) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Insufficient data for inflate"); return APR_EGENERAL; } else { zlib_method = data[2]; zlib_flags = data[3]; if (zlib_method != Z_DEFLATED) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "inflate: data not deflated!"); ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } if (data[0] != deflate_magic[0] || data[1] != deflate_magic[1] || (zlib_flags & RESERVED) != 0) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "inflate: bad header"); return APR_EGENERAL ; } data += 10 ; len -= 10 ; } if (zlib_flags & EXTRA_FIELD) { unsigned int bytes = (unsigned int)(data[0]); bytes += ((unsigned int)(data[1])) << 8; bytes += 2; if (len < bytes) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "inflate: extra field too big (not " "supported)"); return APR_EGENERAL; } data += bytes; len -= bytes; } if (zlib_flags & ORIG_NAME) { while (len-- && *data++); } if (zlib_flags & COMMENT) { while (len-- && *data++); } if (zlib_flags & HEAD_CRC) { len -= 2; data += 2; } } /* pass through zlib inflate. */ ctx->stream.next_in = (unsigned char *)data; ctx->stream.avail_in = len; if (ctx->validation_buffer) { if (ctx->validation_buffer_length < VALIDATION_SIZE) { apr_size_t copy_size; copy_size = VALIDATION_SIZE - ctx->validation_buffer_length; if (copy_size > ctx->stream.avail_in) copy_size = ctx->stream.avail_in; memcpy(ctx->validation_buffer + ctx->validation_buffer_length, ctx->stream.next_in, copy_size); /* Saved copy_size bytes */ ctx->stream.avail_in -= copy_size; ctx->validation_buffer_length += copy_size; } if (ctx->stream.avail_in) { ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "Zlib: %d bytes of garbage at the end of " "compressed stream.", ctx->stream.avail_in); /* * There is nothing worth consuming for zlib left, because it is * either garbage data or the data has been copied to the * validation buffer (processing validation data is no business * for zlib). So set ctx->stream.avail_in to zero to indicate * this to the following while loop. */ ctx->stream.avail_in = 0; } } zRC = Z_OK; while (ctx->stream.avail_in != 0) { if (ctx->stream.avail_out == 0) { ctx->stream.next_out = ctx->buffer; len = c->bufferSize - ctx->stream.avail_out; ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len); b = apr_bucket_heap_create((char *)ctx->buffer, len, NULL, f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->bb, b); ctx->stream.avail_out = c->bufferSize; /* Send what we have right now to the next filter. */ rv = ap_pass_brigade(f->next, ctx->bb); if (rv != APR_SUCCESS) { return rv; } } zRC = inflate(&ctx->stream, Z_NO_FLUSH); if (zRC == Z_STREAM_END) { /* * We have inflated all data. Now try to capture the * validation bytes. We may not have them all available * right now, but capture what is there. */ ctx->validation_buffer = apr_pcalloc(f->r->pool, VALIDATION_SIZE); if (ctx->stream.avail_in > VALIDATION_SIZE) { ctx->validation_buffer_length = VALIDATION_SIZE; ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, "Zlib: %d bytes of garbage at the end of " "compressed stream.", ctx->stream.avail_in - VALIDATION_SIZE); } else if (ctx->stream.avail_in > 0) { ctx->validation_buffer_length = ctx->stream.avail_in; } if (ctx->validation_buffer_length) memcpy(ctx->validation_buffer, ctx->stream.next_in, ctx->validation_buffer_length); break; } if (zRC != Z_OK) { return APR_EGENERAL; } } apr_bucket_delete(e); } apr_brigade_cleanup(bb); return APR_SUCCESS; } #define PROTO_FLAGS AP_FILTER_PROTO_CHANGE|AP_FILTER_PROTO_CHANGE_LENGTH static void register_hooks(apr_pool_t *p) { ap_register_output_filter(deflateFilterName, deflate_out_filter, NULL, AP_FTYPE_CONTENT_SET); ap_register_output_filter("INFLATE", inflate_out_filter, NULL, AP_FTYPE_RESOURCE-1); ap_register_input_filter(deflateFilterName, deflate_in_filter, NULL, AP_FTYPE_CONTENT_SET); } static const command_rec deflate_filter_cmds[] = { AP_INIT_TAKE12("DeflateFilterNote", deflate_set_note, NULL, RSRC_CONF, "Set a note to report on compression ratio"), AP_INIT_TAKE1("DeflateWindowSize", deflate_set_window_size, NULL, RSRC_CONF, "Set the Deflate window size (1-15)"), AP_INIT_TAKE1("DeflateBufferSize", deflate_set_buffer_size, NULL, RSRC_CONF, "Set the Deflate Buffer Size"), AP_INIT_TAKE1("DeflateMemLevel", deflate_set_memlevel, NULL, RSRC_CONF, "Set the Deflate Memory Level (1-9)"), AP_INIT_TAKE1("DeflateCompressionLevel", deflate_set_compressionlevel, NULL, RSRC_CONF, "Set the Deflate Compression Level (1-9)"), {NULL} }; module AP_MODULE_DECLARE_DATA deflate_module = { STANDARD20_MODULE_STUFF, NULL, /* dir config creater */ NULL, /* dir merger --- default is to override */ create_deflate_server_config, /* server config */ NULL, /* merge server config */ deflate_filter_cmds, /* command table */ register_hooks /* register hooks */ };
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