From 868c9531cdc95a0d4ceef1f7f8306df194f03d6f Mon Sep 17 00:00:00 2001
From: Ad Schellevis <ad@opnsense.org>
Date: Tue, 19 Jul 2022 20:13:00 +0200
Subject: [PATCH] system: remove last bits of clog (circular logging) support,
 closes https://github.com/opnsense/core/issues/5892

---
 src/opnsense/scripts/filter/read_log.py       |  8 ++------
 src/opnsense/scripts/systemhealth/clearlog    |  2 +-
 src/opnsense/scripts/systemhealth/queryLog.py | 12 ++++--------
 src/opnsense/site-python/log_helper.py        | 19 +------------------
 4 files changed, 8 insertions(+), 33 deletions(-)

diff --git a/src/opnsense/scripts/filter/read_log.py b/src/opnsense/scripts/filter/read_log.py
index d2a1f67c7..742e79f70 100755
--- a/src/opnsense/scripts/filter/read_log.py
+++ b/src/opnsense/scripts/filter/read_log.py
@@ -37,7 +37,7 @@ import argparse
 import ujson
 import subprocess
 sys.path.insert(0, "/usr/local/opnsense/site-python")
-from log_helper import reverse_log_reader, fetch_clog
+from log_helper import reverse_log_reader
 from params import update_params
 
 
@@ -107,12 +107,8 @@ if __name__ == '__main__':
     if os.path.isfile('/var/log/filter.log'):
         filter_logs.append('/var/log/filter.log')
 
-    for filter_log in filter_logs:
+    for filename in filter_logs:
         do_exit = False
-        try:
-            filename = fetch_clog(filter_log)
-        except Exception as e:
-            filename = filter_log
         for record in reverse_log_reader(filename):
             if record['line'].find('filterlog') > -1:
                 rule = dict()
diff --git a/src/opnsense/scripts/systemhealth/clearlog b/src/opnsense/scripts/systemhealth/clearlog
index 8d18e83ed..7bad0f78c 100755
--- a/src/opnsense/scripts/systemhealth/clearlog
+++ b/src/opnsense/scripts/systemhealth/clearlog
@@ -57,9 +57,9 @@ if (isset($opts['m']) && isset($opts['f'])) {
         system_syslog_start();
     }
 
+    // non syslog files, in case service doesn't use our default syslog naming
     $filename = "{$basename}.log";
     if (is_file($filename)) {
-        // remove legacy clog file
         @unlink($filename);
         system_syslog_start();
         // XXX: should probably add some plugin hook for this.
diff --git a/src/opnsense/scripts/systemhealth/queryLog.py b/src/opnsense/scripts/systemhealth/queryLog.py
index c3712edef..2d8b74f94 100755
--- a/src/opnsense/scripts/systemhealth/queryLog.py
+++ b/src/opnsense/scripts/systemhealth/queryLog.py
@@ -39,7 +39,7 @@ import datetime
 import glob
 from logformats import FormatContainer, BaseLogFormat
 sys.path.insert(0, "/usr/local/opnsense/site-python")
-from log_helper import reverse_log_reader, fetch_clog
+from log_helper import reverse_log_reader
 import argparse
 
 if __name__ == '__main__':
@@ -85,13 +85,9 @@ if __name__ == '__main__':
             filter_regexp = re.compile('.*')
 
         row_number = 0
-        for log_filename in log_filenames:
-            if os.path.exists(log_filename):
-                format_container = FormatContainer(log_filename)
-                try:
-                    filename = fetch_clog(log_filename)
-                except Exception as e:
-                    filename = log_filename
+        for filename in log_filenames:
+            if os.path.exists(filename):
+                format_container = FormatContainer(filename)
                 for rec in reverse_log_reader(filename):
                     row_number += 1
                     if rec['line'] != "" and filter_regexp.match(('%s' % rec['line']).lower()):
diff --git a/src/opnsense/site-python/log_helper.py b/src/opnsense/site-python/log_helper.py
index 644c99c03..884ceadd5 100644
--- a/src/opnsense/site-python/log_helper.py
+++ b/src/opnsense/site-python/log_helper.py
@@ -1,5 +1,5 @@
 """
-    Copyright (c) 2015-2019 Ad Schellevis <ad@opnsense.org>
+    Copyright (c) 2015-2022 Ad Schellevis <ad@opnsense.org>
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -74,20 +74,3 @@ def reverse_log_reader(filename, block_size=81920, start_pos=None):
 
         if file_byte_start == 0 and bol == -1:
             yield {'line': data.strip().strip('\u0000'), 'pos': len(data)}
-
-def fetch_clog(input_log):
-    """ fetch clog file (circular log)
-    :param input_log: clog input file
-    :return: stringIO
-    """
-    with open(input_log, 'r+b') as fd:
-        # clog to memory
-        mm = mmap.mmap(fd.fileno(), 0)
-        # unpack clog information struct
-        clog_footer = struct.unpack('iiii', mm[-16:])  # cf_magic, cf_wrap, cf_next, cf_max, cf_lock
-        if mm[-20:-16] != b'CLOG':
-            raise Exception('not a valid clog file')
-        # concat log file into new output stream, start at current wrap position
-        output_stream = StringIO(mm[clog_footer[1]:-20].decode() + mm[:clog_footer[1]].decode())
-        output_stream.seek(0)
-        return output_stream