[pve-devel] [PATCH common 1/1] tools: Add callback based filtering for firewall logfiles

[Christian Ebner <c.ebner@proxmox.com>]

This patch introduces callback based filtering functionality for firewall logs.
In addition, the contents of rotated logfiles are included by setting the
`include_rotated_logs` flag.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
---
 src/PVE/Tools.pm | 108 +++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 91 insertions(+), 17 deletions(-)

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index cdbee6d..cafc2f7 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -17,6 +17,7 @@ use IO::Handle;
 use IO::Pipe;
 use IO::Select;
 use IO::Socket::IP;
+use IO::Zlib;
 use IPC::Open3;
 use JSON;
 use POSIX qw(EINTR EEXIST EOPNOTSUPP);
@@ -1265,29 +1266,19 @@ sub split_args {
     return $str ? [ Text::ParseWords::shellwords($str) ] : [];
 }
 
-sub dump_logfile {
-    my ($filename, $start, $limit, $filter) = @_;
-
-    my $lines = [];
-    my $count = 0;
-
-    my $fh = IO::File->new($filename, "r");
-    if (!$fh) {
-	$count++;
-	push @$lines, { n => $count, t => "unable to open file - $!"};
-	return ($count, $lines);
-    }
+sub dump_logfile_by_filehandle {
+    my ($fh, $start, $limit, $filter, $count, $lines, $read_until_end) = @_;
 
-    $start = $start // 0;
-    $limit = $limit // 50;
-
-    my $read_until_end = $limit == 0;
     my $line;
 
     if ($filter) {
 	# duplicate code, so that we do not slow down normal path
 	while (defined($line = <$fh>)) {
-	    next if $line !~ m/$filter/;
+	    if (ref($filter) eq 'CODE') {
+		next if !$filter->($line);
+	    } else {
+		next if $line !~ m/$filter/;
+	    }
 	    next if $count++ < $start;
 	    if (!$read_until_end) {
 		next if $limit <= 0;
@@ -1308,6 +1299,29 @@ sub dump_logfile {
 	}
     }
 
+    return ($count, $lines, $limit);
+}
+
+sub dump_logfile {
+    my ($filename, $start, $limit, $filter) = @_;
+
+    $start = $start // 0;
+    $limit = $limit // 50;
+
+    my $read_until_end = $limit == 0;
+    my $lines = [];
+    my $count = 0;
+
+    my $fh = IO::File->new($filename, "r");
+    if (!$fh) {
+	$count++;
+	push @$lines, { n => $count, t => "unable to open file - $!"};
+	return ($count, $lines);
+    }
+
+    ($count, $lines, $limit) = dump_logfile_by_filehandle(
+	$fh, $start, $limit, $filter, $count, $lines, $read_until_end);
+
     close($fh);
 
     # HACK: ExtJS store.guaranteeRange() does not like empty array
@@ -1320,6 +1334,66 @@ sub dump_logfile {
     return ($count, $lines);
 }
 
+sub dump_fw_logfile {
+    my ($filename, $start, $limit, $filter, $include_rotated_logs) = @_;
+
+    if (!$include_rotated_logs) {
+	return dump_logfile($filename, $start, $limit, $filter);
+    }
+
+    $start = $start // 0;
+    $limit = $limit // 50;
+
+    # Take into consideration also rotated logs                                              
+    my ($basename, $logdir, $type) = fileparse($filename);
+    my @files = ();                                                                          
+
+    opendir(LOGDIR, $logdir) || die "Cannot open $logdir";
+    my $entry;
+    while ($entry = readdir(LOGDIR)) {
+	my $namefilter = $basename."*";
+	next if $entry !~ m/$namefilter/;
+	push @files, $entry;
+    }
+    closedir(LOGDIR);
+    @files = reverse sort @files;
+
+    my $read_until_end = $limit == 0;
+    my $lines = [];
+    my $count = 0;
+
+    foreach (@files) {
+	my ($base, $path, $type) = fileparse($_, ".gz");
+
+	my $fh;
+	if ($type eq '.gz') {
+	    $fh = IO::Zlib->new($logdir.$_, "r");
+	} else {
+	    $fh = IO::File->new($logdir.$_, "r");
+	}
+
+	if (!$fh) {
+	    $count++;
+	    push @$lines, { n => $count, t => "unable to open file - $!"};
+	    return ($count, $lines);
+	}
+
+	($count, $lines, $limit) = dump_logfile_by_filehandle(
+	    $fh, $start, $limit, $filter, $count, $lines, $read_until_end);
+
+	close($fh);
+    }
+
+    # HACK: ExtJS store.guaranteeRange() does not like empty array
+    # so we add a line
+    if (!$count) {
+	$count++;
+	push @$lines, { n => $count, t => "no content"};
+    }
+
+    return ($count, $lines);
+}
+
 sub dump_journal {
     my ($start, $limit, $since, $until, $service) = @_;
 
-- 
2.30.2