| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al. |
| * |
| * This software is licensed as described in the file COPYING, which |
| * you should have received as part of this distribution. The terms |
| * are also available at http://curl.haxx.se/docs/copyright.html. |
| * |
| * You may opt to use, copy, modify, merge, publish, distribute and/or sell |
| * copies of the Software, and permit persons to whom the Software is |
| * furnished to do so, under the terms of the COPYING file. |
| * |
| * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY |
| * KIND, either express or implied. |
| * |
| * $Id$ |
| ***************************************************************************/ |
| |
| #include "setup.h" |
| |
| #ifdef HAVE_LIBZ |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "urldata.h" |
| #include <curl/curl.h> |
| #include "sendf.h" |
| #include "content_encoding.h" |
| #include "memory.h" |
| |
| #include "memdebug.h" |
| |
| /* Comment this out if zlib is always going to be at least ver. 1.2.0.4 |
| (doing so will reduce code size slightly). */ |
| #define OLD_ZLIB_SUPPORT 1 |
| |
| #define DSIZ 0x10000 /* buffer size for decompressed data */ |
| |
| #define GZIP_MAGIC_0 0x1f |
| #define GZIP_MAGIC_1 0x8b |
| |
| /* gzip flag byte */ |
| #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 */ |
| |
| static CURLcode |
| process_zlib_error(struct connectdata *conn, z_stream *z) |
| { |
| struct SessionHandle *data = conn->data; |
| if(z->msg) |
| failf (data, "Error while processing content unencoding: %s", |
| z->msg); |
| else |
| failf (data, "Error while processing content unencoding: " |
| "Unknown failure within decompression software."); |
| |
| return CURLE_BAD_CONTENT_ENCODING; |
| } |
| |
| static CURLcode |
| exit_zlib(z_stream *z, zlibInitState *zlib_init, CURLcode result) |
| { |
| inflateEnd(z); |
| *zlib_init = ZLIB_UNINIT; |
| return result; |
| } |
| |
| static CURLcode |
| inflate_stream(struct connectdata *conn, |
| struct SingleRequest *k) |
| { |
| int allow_restart = 1; |
| z_stream *z = &k->z; /* zlib state structure */ |
| uInt nread = z->avail_in; |
| Bytef *orig_in = z->next_in; |
| int status; /* zlib status */ |
| CURLcode result = CURLE_OK; /* Curl_client_write status */ |
| char *decomp; /* Put the decompressed data here. */ |
| |
| /* Dynamically allocate a buffer for decompression because it's uncommonly |
| large to hold on the stack */ |
| decomp = (char*)malloc(DSIZ); |
| if(decomp == NULL) { |
| return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY); |
| } |
| |
| /* because the buffer size is fixed, iteratively decompress and transfer to |
| the client via client_write. */ |
| for (;;) { |
| /* (re)set buffer for decompressed output for every iteration */ |
| z->next_out = (Bytef *)decomp; |
| z->avail_out = DSIZ; |
| |
| status = inflate(z, Z_SYNC_FLUSH); |
| if(status == Z_OK || status == Z_STREAM_END) { |
| allow_restart = 0; |
| if(DSIZ - z->avail_out) { |
| result = Curl_client_write(conn, CLIENTWRITE_BODY, decomp, |
| DSIZ - z->avail_out); |
| /* if !CURLE_OK, clean up, return */ |
| if(result) { |
| free(decomp); |
| return exit_zlib(z, &k->zlib_init, result); |
| } |
| } |
| |
| /* Done? clean up, return */ |
| if(status == Z_STREAM_END) { |
| free(decomp); |
| if(inflateEnd(z) == Z_OK) |
| return exit_zlib(z, &k->zlib_init, result); |
| else |
| return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z)); |
| } |
| |
| /* Done with these bytes, exit */ |
| if(status == Z_OK && z->avail_in == 0) { |
| free(decomp); |
| return result; |
| } |
| } |
| else if(allow_restart && status == Z_DATA_ERROR) { |
| /* some servers seem to not generate zlib headers, so this is an attempt |
| to fix and continue anyway */ |
| |
| (void) inflateEnd(z); /* don't care about the return code */ |
| if(inflateInit2(z, -MAX_WBITS) != Z_OK) { |
| return process_zlib_error(conn, z); |
| } |
| z->next_in = orig_in; |
| z->avail_in = nread; |
| allow_restart = 0; |
| continue; |
| } |
| else { /* Error; exit loop, handle below */ |
| free(decomp); |
| return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z)); |
| } |
| } |
| /* Will never get here */ |
| } |
| |
| CURLcode |
| Curl_unencode_deflate_write(struct connectdata *conn, |
| struct SingleRequest *k, |
| ssize_t nread) |
| { |
| z_stream *z = &k->z; /* zlib state structure */ |
| |
| /* Initialize zlib? */ |
| if(k->zlib_init == ZLIB_UNINIT) { |
| z->zalloc = (alloc_func)Z_NULL; |
| z->zfree = (free_func)Z_NULL; |
| z->opaque = 0; |
| z->next_in = NULL; |
| z->avail_in = 0; |
| if(inflateInit(z) != Z_OK) |
| return process_zlib_error(conn, z); |
| k->zlib_init = ZLIB_INIT; |
| } |
| |
| /* Set the compressed input when this function is called */ |
| z->next_in = (Bytef *)k->str; |
| z->avail_in = (uInt)nread; |
| |
| /* Now uncompress the data */ |
| return inflate_stream(conn, k); |
| } |
| |
| #ifdef OLD_ZLIB_SUPPORT |
| /* Skip over the gzip header */ |
| static enum { |
| GZIP_OK, |
| GZIP_BAD, |
| GZIP_UNDERFLOW |
| } check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen) |
| { |
| int method, flags; |
| const ssize_t totallen = len; |
| |
| /* The shortest header is 10 bytes */ |
| if(len < 10) |
| return GZIP_UNDERFLOW; |
| |
| if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1)) |
| return GZIP_BAD; |
| |
| method = data[2]; |
| flags = data[3]; |
| |
| if(method != Z_DEFLATED || (flags & RESERVED) != 0) { |
| /* Can't handle this compression method or unknown flag */ |
| return GZIP_BAD; |
| } |
| |
| /* Skip over time, xflags, OS code and all previous bytes */ |
| len -= 10; |
| data += 10; |
| |
| if(flags & EXTRA_FIELD) { |
| ssize_t extra_len; |
| |
| if(len < 2) |
| return GZIP_UNDERFLOW; |
| |
| extra_len = (data[1] << 8) | data[0]; |
| |
| if(len < (extra_len+2)) |
| return GZIP_UNDERFLOW; |
| |
| len -= (extra_len + 2); |
| data += (extra_len + 2); |
| } |
| |
| if(flags & ORIG_NAME) { |
| /* Skip over NUL-terminated file name */ |
| while(len && *data) { |
| --len; |
| ++data; |
| } |
| if(!len || *data) |
| return GZIP_UNDERFLOW; |
| |
| /* Skip over the NUL */ |
| --len; |
| ++data; |
| } |
| |
| if(flags & COMMENT) { |
| /* Skip over NUL-terminated comment */ |
| while(len && *data) { |
| --len; |
| ++data; |
| } |
| if(!len || *data) |
| return GZIP_UNDERFLOW; |
| |
| /* Skip over the NUL */ |
| --len; |
| ++data; |
| } |
| |
| if(flags & HEAD_CRC) { |
| if(len < 2) |
| return GZIP_UNDERFLOW; |
| |
| len -= 2; |
| data += 2; |
| } |
| |
| *headerlen = totallen - len; |
| return GZIP_OK; |
| } |
| #endif |
| |
| CURLcode |
| Curl_unencode_gzip_write(struct connectdata *conn, |
| struct SingleRequest *k, |
| ssize_t nread) |
| { |
| z_stream *z = &k->z; /* zlib state structure */ |
| |
| /* Initialize zlib? */ |
| if(k->zlib_init == ZLIB_UNINIT) { |
| z->zalloc = (alloc_func)Z_NULL; |
| z->zfree = (free_func)Z_NULL; |
| z->opaque = 0; |
| z->next_in = NULL; |
| z->avail_in = 0; |
| |
| if(strcmp(zlibVersion(), "1.2.0.4") >= 0) { |
| /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */ |
| if(inflateInit2(z, MAX_WBITS+32) != Z_OK) { |
| return process_zlib_error(conn, z); |
| } |
| k->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */ |
| |
| } else { |
| /* we must parse the gzip header ourselves */ |
| if(inflateInit2(z, -MAX_WBITS) != Z_OK) { |
| return process_zlib_error(conn, z); |
| } |
| k->zlib_init = ZLIB_INIT; /* Initial call state */ |
| } |
| } |
| |
| if(k->zlib_init == ZLIB_INIT_GZIP) { |
| /* Let zlib handle the gzip decompression entirely */ |
| z->next_in = (Bytef *)k->str; |
| z->avail_in = (uInt)nread; |
| /* Now uncompress the data */ |
| return inflate_stream(conn, k); |
| } |
| |
| #ifndef OLD_ZLIB_SUPPORT |
| /* Support for old zlib versions is compiled away and we are running with |
| an old version, so return an error. */ |
| return exit_zlib(z, &k->zlib_init, CURLE_FUNCTION_NOT_FOUND); |
| |
| #else |
| /* This next mess is to get around the potential case where there isn't |
| * enough data passed in to skip over the gzip header. If that happens, we |
| * malloc a block and copy what we have then wait for the next call. If |
| * there still isn't enough (this is definitely a worst-case scenario), we |
| * make the block bigger, copy the next part in and keep waiting. |
| * |
| * This is only required with zlib versions < 1.2.0.4 as newer versions |
| * can handle the gzip header themselves. |
| */ |
| |
| switch (k->zlib_init) { |
| /* Skip over gzip header? */ |
| case ZLIB_INIT: |
| { |
| /* Initial call state */ |
| ssize_t hlen; |
| |
| switch (check_gzip_header((unsigned char *)k->str, nread, &hlen)) { |
| case GZIP_OK: |
| z->next_in = (Bytef *)k->str + hlen; |
| z->avail_in = (uInt)(nread - hlen); |
| k->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */ |
| break; |
| |
| case GZIP_UNDERFLOW: |
| /* We need more data so we can find the end of the gzip header. It's |
| * possible that the memory block we malloc here will never be freed if |
| * the transfer abruptly aborts after this point. Since it's unlikely |
| * that circumstances will be right for this code path to be followed in |
| * the first place, and it's even more unlikely for a transfer to fail |
| * immediately afterwards, it should seldom be a problem. |
| */ |
| z->avail_in = (uInt)nread; |
| z->next_in = malloc(z->avail_in); |
| if(z->next_in == NULL) { |
| return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY); |
| } |
| memcpy(z->next_in, k->str, z->avail_in); |
| k->zlib_init = ZLIB_GZIP_HEADER; /* Need more gzip header data state */ |
| /* We don't have any data to inflate yet */ |
| return CURLE_OK; |
| |
| case GZIP_BAD: |
| default: |
| return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z)); |
| } |
| |
| } |
| break; |
| |
| case ZLIB_GZIP_HEADER: |
| { |
| /* Need more gzip header data state */ |
| ssize_t hlen; |
| unsigned char *oldblock = z->next_in; |
| |
| z->avail_in += nread; |
| z->next_in = realloc(z->next_in, z->avail_in); |
| if(z->next_in == NULL) { |
| free(oldblock); |
| return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY); |
| } |
| /* Append the new block of data to the previous one */ |
| memcpy(z->next_in + z->avail_in - nread, k->str, nread); |
| |
| switch (check_gzip_header(z->next_in, z->avail_in, &hlen)) { |
| case GZIP_OK: |
| /* This is the zlib stream data */ |
| free(z->next_in); |
| /* Don't point into the malloced block since we just freed it */ |
| z->next_in = (Bytef *)k->str + hlen + nread - z->avail_in; |
| z->avail_in = (uInt)(z->avail_in - hlen); |
| k->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */ |
| break; |
| |
| case GZIP_UNDERFLOW: |
| /* We still don't have any data to inflate! */ |
| return CURLE_OK; |
| |
| case GZIP_BAD: |
| default: |
| free(z->next_in); |
| return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z)); |
| } |
| |
| } |
| break; |
| |
| case ZLIB_GZIP_INFLATING: |
| default: |
| /* Inflating stream state */ |
| z->next_in = (Bytef *)k->str; |
| z->avail_in = (uInt)nread; |
| break; |
| } |
| |
| if(z->avail_in == 0) { |
| /* We don't have any data to inflate; wait until next time */ |
| return CURLE_OK; |
| } |
| |
| /* We've parsed the header, now uncompress the data */ |
| return inflate_stream(conn, k); |
| #endif |
| } |
| #endif /* HAVE_LIBZ */ |
