lnav/src/file_format.cc
2022-03-31 08:59:33 -07:00

120 lines
3.7 KiB
C++

/**
* Copyright (c) 2020, Timothy Stack
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Timothy Stack nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
* EXPRESS 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 REGENTS OR 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.
*
* @file file_format.hh
*/
#include <unordered_map>
#include "file_format.hh"
#include "archive_manager.hh"
#include "base/auto_fd.hh"
#include "base/fs_util.hh"
#include "base/intern_string.hh"
#include "base/lnav_log.hh"
#include "config.h"
static bool
is_pcap_header(uint8_t* buffer)
{
size_t offset = 0;
if (buffer[0] == 0x0a && buffer[1] == 0x0d && buffer[2] == 0x0d
&& buffer[3] == 0x0a)
{
offset += sizeof(uint32_t) * 2;
if (buffer[offset + 0] == 0x1a && buffer[offset + 1] == 0x2b
&& buffer[offset + 2] == 0x3c && buffer[offset + 3] == 0x4d)
{
return true;
}
if (buffer[offset + 0] == 0x4d && buffer[offset + 1] == 0x3c
&& buffer[offset + 2] == 0x2b && buffer[offset + 3] == 0x1a)
{
return true;
}
return false;
}
if (buffer[0] == 0xa1 && buffer[1] == 0xb2 && buffer[2] == 0xc3
&& buffer[3] == 0xd4)
{
return true;
}
if (buffer[0] == 0xd4 && buffer[1] == 0xc3 && buffer[2] == 0xb2
&& buffer[3] == 0xa1)
{
return true;
}
if (buffer[0] == 0xa1 && buffer[1] == 0xb2 && buffer[2] == 0x3c
&& buffer[3] == 0x4d)
{
return true;
}
if (buffer[0] == 0x4d && buffer[1] == 0x3c && buffer[2] == 0xb2
&& buffer[3] == 0xa1)
{
return true;
}
return false;
}
file_format_t
detect_file_format(const ghc::filesystem::path& filename)
{
if (archive_manager::is_archive(filename)) {
return file_format_t::ARCHIVE;
}
file_format_t retval = file_format_t::UNKNOWN;
auto_fd fd;
if ((fd = lnav::filesystem::openp(filename, O_RDONLY)) != -1) {
uint8_t buffer[32];
ssize_t rc;
if ((rc = read(fd, buffer, sizeof(buffer))) > 0) {
static auto SQLITE3_HEADER = "SQLite format 3";
auto header_frag = string_fragment(buffer, 0, rc);
if (header_frag.startswith(SQLITE3_HEADER)) {
retval = file_format_t::SQLITE_DB;
} else if (rc > 24 && is_pcap_header(buffer)) {
retval = file_format_t::PCAP;
}
}
}
return retval;
}