123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182 |
- // Copyright 2014 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #include "net/filter/gzip_header.h"
- #include <string.h>
- #include <algorithm>
- #include "base/check_op.h"
- #include "third_party/zlib/zlib.h"
- namespace net {
- const uint8_t GZipHeader::magic[] = {0x1f, 0x8b};
- GZipHeader::GZipHeader() {
- Reset();
- }
- GZipHeader::~GZipHeader() = default;
- void GZipHeader::Reset() {
- state_ = IN_HEADER_ID1;
- flags_ = 0;
- extra_length_ = 0;
- }
- GZipHeader::Status GZipHeader::ReadMore(const char* inbuf,
- size_t inbuf_len,
- const char** header_end) {
- const uint8_t* pos = reinterpret_cast<const uint8_t*>(inbuf);
- const uint8_t* const end = pos + inbuf_len;
- while ( pos < end ) {
- switch ( state_ ) {
- case IN_HEADER_ID1:
- if ( *pos != magic[0] ) return INVALID_HEADER;
- pos++;
- state_++;
- break;
- case IN_HEADER_ID2:
- if ( *pos != magic[1] ) return INVALID_HEADER;
- pos++;
- state_++;
- break;
- case IN_HEADER_CM:
- if ( *pos != Z_DEFLATED ) return INVALID_HEADER;
- pos++;
- state_++;
- break;
- case IN_HEADER_FLG:
- flags_ = (*pos) & (FLAG_FHCRC | FLAG_FEXTRA |
- FLAG_FNAME | FLAG_FCOMMENT);
- pos++;
- state_++;
- break;
- case IN_HEADER_MTIME_BYTE_0:
- pos++;
- state_++;
- break;
- case IN_HEADER_MTIME_BYTE_1:
- pos++;
- state_++;
- break;
- case IN_HEADER_MTIME_BYTE_2:
- pos++;
- state_++;
- break;
- case IN_HEADER_MTIME_BYTE_3:
- pos++;
- state_++;
- break;
- case IN_HEADER_XFL:
- pos++;
- state_++;
- break;
- case IN_HEADER_OS:
- pos++;
- state_++;
- break;
- case IN_XLEN_BYTE_0:
- if ( !(flags_ & FLAG_FEXTRA) ) {
- state_ = IN_FNAME;
- break;
- }
- // We have a two-byte little-endian length, followed by a
- // field of that length.
- extra_length_ = *pos;
- pos++;
- state_++;
- break;
- case IN_XLEN_BYTE_1:
- extra_length_ += *pos << 8;
- pos++;
- state_++;
- // We intentionally fall through, because if we have a
- // zero-length FEXTRA, we want to check to notice that we're
- // done reading the FEXTRA before we exit this loop...
- [[fallthrough]];
- case IN_FEXTRA: {
- // Grab the rest of the bytes in the extra field, or as many
- // of them as are actually present so far.
- const uint16_t num_extra_bytes = static_cast<uint16_t>(
- std::min(static_cast<ptrdiff_t>(extra_length_), (end - pos)));
- pos += num_extra_bytes;
- extra_length_ -= num_extra_bytes;
- if ( extra_length_ == 0 ) {
- state_ = IN_FNAME; // advance when we've seen extra_length_ bytes
- flags_ &= ~FLAG_FEXTRA; // we're done with the FEXTRA stuff
- }
- break;
- }
- case IN_FNAME:
- if ( !(flags_ & FLAG_FNAME) ) {
- state_ = IN_FCOMMENT;
- break;
- }
- // See if we can find the end of the \0-terminated FNAME field.
- pos = reinterpret_cast<const uint8_t*>(memchr(pos, '\0', (end - pos)));
- if (pos != nullptr) {
- pos++; // advance past the '\0'
- flags_ &= ~FLAG_FNAME; // we're done with the FNAME stuff
- state_ = IN_FCOMMENT;
- } else {
- pos = end; // everything we have so far is part of the FNAME
- }
- break;
- case IN_FCOMMENT:
- if ( !(flags_ & FLAG_FCOMMENT) ) {
- state_ = IN_FHCRC_BYTE_0;
- break;
- }
- // See if we can find the end of the \0-terminated FCOMMENT field.
- pos = reinterpret_cast<const uint8_t*>(memchr(pos, '\0', (end - pos)));
- if (pos != nullptr) {
- pos++; // advance past the '\0'
- flags_ &= ~FLAG_FCOMMENT; // we're done with the FCOMMENT stuff
- state_ = IN_FHCRC_BYTE_0;
- } else {
- pos = end; // everything we have so far is part of the FNAME
- }
- break;
- case IN_FHCRC_BYTE_0:
- if ( !(flags_ & FLAG_FHCRC) ) {
- state_ = IN_DONE;
- break;
- }
- pos++;
- state_++;
- break;
- case IN_FHCRC_BYTE_1:
- pos++;
- flags_ &= ~FLAG_FHCRC; // we're done with the FHCRC stuff
- state_++;
- break;
- case IN_DONE:
- *header_end = reinterpret_cast<const char*>(pos);
- return COMPLETE_HEADER;
- }
- }
- if ( (state_ > IN_HEADER_OS) && (flags_ == 0) ) {
- *header_end = reinterpret_cast<const char*>(pos);
- return COMPLETE_HEADER;
- } else {
- return INCOMPLETE_HEADER;
- }
- }
- } // namespace net
|