/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 2000-2002 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Apache" and "Apache Software Foundation" must * not be used to endorse or promote products derived from this * software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache", * nor may "Apache" appear in their name, without prior written * permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * . * * Portions of this software are based upon public domain software * (zlib functions gz_open and gzwrite) */ /* * mod_deflate.c: Perform deflate transfer-encoding on the fly * * Written by Ian Holsman (IanH@apache.org) * */ #include "httpd.h" #include "http_config.h" #include "http_log.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" #ifdef HAVE_ZUTIL_H #include "zutil.h" #else /* As part of the encoding process, we must send what our OS_CODE is * (or so it seems based on what I can tell of how gzip encoding works). * * zutil.h is not always included with zlib distributions (it is a private * header), so this is straight from zlib 1.1.3's zutil.h. */ #ifdef OS2 #define OS_CODE 0x06 #endif #ifdef WIN32 /* Window 95 & Windows NT */ #define OS_CODE 0x0b #endif #if defined(VAXC) || defined(VMS) #define OS_CODE 0x02 #endif #ifdef AMIGA #define OS_CODE 0x01 #endif #if defined(ATARI) || defined(atarist) #define OS_CODE 0x05 #endif #if defined(MACOS) || defined(TARGET_OS_MAC) #define OS_CODE 0x07 #endif #ifdef __50SERIES /* Prime/PRIMOS */ #define OS_CODE 0x0F #endif #ifdef TOPS20 #define OS_CODE 0x0a #endif #ifndef OS_CODE #define OS_CODE 0x03 /* assume Unix */ #endif #endif static const char deflateFilterName[] = "DEFLATE"; module AP_MODULE_DECLARE_DATA deflate_module; typedef struct deflate_filter_config_t { int windowSize; int memlevel; int bufferSize; char *noteName; } deflate_filter_config; /* windowsize is negative to suppress Zlib header */ #define DEFAULT_WINDOWSIZE -15 #define DEFAULT_MEMLEVEL 9 #define DEFAULT_BUFFERSIZE 8096 /* 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; 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); c->bufferSize = atoi(arg); if (c->bufferSize <= 0) { return "DeflateBufferSize should be positive"; } return NULL; } static const char *deflate_set_note(cmd_parms *cmd, void *dummy, const char *arg) { deflate_filter_config *c = ap_get_module_config(cmd->server->module_config, &deflate_module); c->noteName = apr_pstrdup(cmd->pool, arg); 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; } /* magic header */ static char deflate_magic[2] = { '\037', '\213' }; typedef struct deflate_ctx_t { z_stream stream; unsigned char *buffer; unsigned long crc; apr_bucket_brigade *bb, *proc_bb; } deflate_ctx; 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 = 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 *buf, *token; const char *encoding, *accepts; /* only work on main request/no subrequests */ if (r->main) { 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); } /* 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)) && apr_table_get(r->subprocess_env, "gzip-only-text/html")) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* Let's see what our current Content-Encoding is. * If gzip is present, don't gzip again. (We could, but let's not.) */ encoding = apr_table_get(r->headers_out, "Content-Encoding"); if (encoding) { const char *tmp = encoding; token = ap_get_token(r->pool, &tmp, 0); while (token && token[0]) { if (!strcasecmp(token, "gzip")) { ap_remove_output_filter(f); return ap_pass_brigade(f->next, bb); } /* Otherwise, skip token */ tmp++; token = ap_get_token(r->pool, &tmp, 0); } } /* 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 token */ accepts++; token = ap_get_token(r->pool, &accepts, 0); } /* No acceptable token found. */ if (token == NULL || token[0] == '\0') { 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); zRC = deflateInit2(&ctx->stream, Z_BEST_SPEED, Z_DEFLATED, c->windowSize, c->memlevel, Z_DEFAULT_STRATEGY); if (zRC != Z_OK) { f->ctx = NULL; ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "unable to init Zlib: " "deflateInit2 returned %d: URL %s", zRC, r->uri); return ap_pass_brigade(f->next, bb); } /* RFC 1952 Section 2.3 dictates the gzip header: * * +---+---+---+---+---+---+---+---+---+---+ * |ID1|ID2|CM |FLG| MTIME |XFL|OS | * +---+---+---+---+---+---+---+---+---+---+ * * If we wish to populate in MTIME (as hinted in RFC 1952), do: * putLong(date_array, apr_time_now() / APR_USEC_PER_SEC); * where date_array is a char[4] and then print date_array in the * MTIME position. WARNING: ENDIANNESS ISSUE HERE. */ buf = apr_psprintf(r->pool, "%c%c%c%c%c%c%c%c%c%c", deflate_magic[0], deflate_magic[1], Z_DEFLATED, 0 /* flags */, 0, 0, 0, 0 /* 4 chars for mtime */, 0 /* xflags */, OS_CODE); e = apr_bucket_pool_create(buf, 10, r->pool, 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_setn(r->headers_out, "Vary", "Accept-Encoding"); apr_table_unset(r->headers_out, "Content-Length"); /* initialize deflate output buffer */ ctx->stream.next_out = ctx->buffer; ctx->stream.avail_out = c->bufferSize; } APR_BRIGADE_FOREACH(e, bb) { const char *data; apr_bucket *b; apr_size_t len; int done = 0; if (APR_BUCKET_IS_EOS(e)) { char *buf; unsigned int deflate_len; ctx->stream.avail_in = 0; /* should be zero already anyway */ for (;;) { deflate_len = c->bufferSize - ctx->stream.avail_out; if (deflate_len != 0) { b = apr_bucket_heap_create((char *)ctx->buffer, deflate_len, NULL, f->c->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 = deflate(&ctx->stream, Z_FINISH); if (deflate_len == 0 && zRC == Z_BUF_ERROR) { zRC = Z_OK; } done = (ctx->stream.avail_out != 0 || zRC == Z_STREAM_END); if (zRC != Z_OK && zRC != Z_STREAM_END) { break; } } buf = apr_palloc(r->pool, 8); putLong((unsigned char *)&buf[0], ctx->crc); putLong((unsigned char *)&buf[4], ctx->stream.total_in); b = apr_bucket_pool_create(buf, 8, 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); if (c->noteName) { if (ctx->stream.total_in > 0) { int total; total = ctx->stream.total_out * 100 / ctx->stream.total_in; apr_table_setn(r->notes, c->noteName, apr_itoa(r->pool, total)); } else { apr_table_setn(r->notes, c->noteName, "-"); } } deflateEnd(&ctx->stream); /* 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_bucket *bkt; zRC = deflate(&(ctx->stream), Z_SYNC_FLUSH); if (zRC != Z_OK) { return APR_EGENERAL; } 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; bkt = apr_bucket_flush_create(f->c->bucket_alloc); APR_BRIGADE_INSERT_TAIL(ctx->bb, bkt); ap_pass_brigade(f->next, ctx->bb); 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) { 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; } zRC = deflate(&(ctx->stream), Z_NO_FLUSH); if (zRC != Z_OK) return APR_EGENERAL; } } apr_brigade_destroy(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) { int found = 0; char *token, deflate_hdr[10]; const char *encoding; apr_size_t len; /* only work on main request/no subrequests */ if (r->main) { ap_remove_input_filter(f); return ap_get_brigade(f->next, bb, mode, block, readbytes); } /* Let's see what our current Content-Encoding is. * If gzip is present, don't gzip again. (We could, but let's not.) */ encoding = apr_table_get(r->headers_in, "Content-Encoding"); if (encoding) { const char *tmp = encoding; token = ap_get_token(r->pool, &tmp, 0); while (token && token[0]) { if (!strcasecmp(token, "gzip")) { found = 1; break; } /* Otherwise, skip token */ tmp++; token = ap_get_token(r->pool, &tmp, 0); } } if (found == 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; } 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; 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) { return rv; } APR_BRIGADE_FOREACH(bkt, ctx->bb) { const char *data; apr_size_t len; /* If we actually see the EOS, that means we screwed up! */ if (APR_BUCKET_IS_EOS(bkt)) { return APR_EGENERAL; } if (APR_BUCKET_IS_FLUSH(bkt)) { apr_bucket *tmp_heap; zRC = inflate(&(ctx->stream), Z_SYNC_FLUSH); if (zRC != Z_OK) { 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) { 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) { return APR_EGENERAL; } ctx->stream.next_in += 4; compLen = getLong(ctx->stream.next_in); if (ctx->stream.total_out != compLen) { return APR_EGENERAL; } } else { /* FIXME: We need to grab the 8 verification bytes * from the wire! */ 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 (!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; } static void register_hooks(apr_pool_t *p) { ap_register_output_filter(deflateFilterName, deflate_out_filter, AP_FTYPE_CONTENT_SET); ap_register_input_filter(deflateFilterName, deflate_in_filter, AP_FTYPE_CONTENT_SET); } static const command_rec deflate_filter_cmds[] = { AP_INIT_TAKE1("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)"), {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 */ };