1 files changed, 119 insertions, 0 deletions
diff --git a/src/file_format.cc b/src/file_format.cc
new file mode 100644
index 0000000..d82b78c
--- /dev/null
+++ b/src/file_format.cc
@@ -0,0 +1,119 @@
+/**
+ * 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;
+}