From: mivirl <>
Date: Wed, 7 Feb 2024 16:22:52 +0000 (-0600)
Subject: client: Add comments explaining behavior
X-Git-Url: http://mivirl.dev/git/?a=commitdiff_plain;h=23f6ad789639e60670a62e86dd876a2fa2e441ec;p=remote-logging.git

client: Add comments explaining behavior
---

diff --git a/src/client.pl b/src/client.pl
index 16bae4c..6999ee6 100644
--- a/src/client.pl
+++ b/src/client.pl
@@ -88,6 +88,8 @@ sub register {
     my $socket = connect_to_server;
     $socket->send("register\n");
     $socket->send("$hostname\n");
+
+    # Wait for connection to be established, try up to 5 times
     my $response;
     foreach (1..5) {
         sleep $_;
@@ -107,7 +109,9 @@ sub register {
 
 sub login {
     my $socket = connect_to_server;
-    my $response = "";
+
+    # Wait for connection to be established, try up to 5 times
+    my $response;
     $socket->send("login\n");
     $socket->send("$clientName\n");
     $socket->send("$clientKey\n");
@@ -127,7 +131,9 @@ sub login {
 
 sub send_info {
     my $socket = login($clientName, $clientKey);
+
     my $info = join "", ns_system('./busybox',  'sh', '-c', 'hostname; date; uname -a; lspci; lsusb; ifconfig');
+
     $socket->send("info\n");
     $socket->send($info);
     $socket->send("⟃---EOF---⟄\n");
@@ -142,9 +148,16 @@ sub send_log {
         return;
     }
 
+    # Check that log exists and is readable by current user
     exit if (! -e $file || ! -r _);
+
     my $socket = login($clientName, $clientKey);
+
+    # Replace / character with similar-looking character that is valid
+    # for filenames. Used to show full path to file
     my $fileName = $file =~ s/\//／/gr;
+
+    # Upload tailed log continuously
     $socket->send("log\n");
     $socket->send("$fileName\n");
     print_log "Log: Uploading $file";
@@ -166,6 +179,8 @@ sub send_processes {
     }
 
     my $socket = login($clientName, $clientKey);
+
+    # Upload process log continuously
     $socket->send("processes\n");
     print_log "Processes: Started";
     my $commandLog = ns_systemFH('./pspy64', '-f');
@@ -187,6 +202,8 @@ sub send_command_output {
     }
 
     my $socket = login($clientName, $clientKey);
+
+    # Upload command output continously with provided filename
     my ($fileName) = $name;
     $socket->send("command\n");
     $socket->send("$fileName\n");
@@ -209,13 +226,20 @@ sub send_file {
         return;
     }
 
+    # Check that log exists and is readable by current user
     exit if (! -e $file || ! -r _);
+
+    # Replace / character with similar-looking character that is valid
+    # for filenames. Used to show full path to file
     my $fileName = $file =~ s/\//／/gr;
     my ($fileHash) = ns_system('./busybox', 'md5sum', "$file");
     chomp $fileName; chomp $fileHash;
     ($fileHash) = $fileHash =~ m/([0-9a-f]+)/;
 
     my $socket = login($clientName, $clientKey);
+
+    # Send filename and hash to server, wait for a response with the port to
+    # upload the file to
     $socket->send("file\n");
     $socket->send("$fileName\n");
     $socket->send("$fileHash\n");
@@ -223,6 +247,7 @@ sub send_file {
     $socket->recv(my $port, 128);
     ($port) = $port =~ m/(\d+)/;
 
+    # Send file once
     print_log "File: upload port is $port ($file)";
     open(my $fileFH, '<', "$file") || die "Failed to open $file";
     my $fileSocket = connect_to_server $port;
@@ -232,10 +257,11 @@ sub send_file {
     close($fileFH);
     close($fileSocket);
 
+    # Server checks that the uploaded hash matches and informs on error
+    # No retry is attempted on failed upload
     $socket->recv(my $response, 128);
     if ($response =~ m/Transfer success/) {
         print_log "File: upload success ($file)";
-        exit;
     } else {
         print_log "File: upload failure ($file)";
     }
@@ -249,6 +275,8 @@ sub watch_directory {
         push @child_processes, $pid;
         return;
     }
+
+    # Recursively monitor directory for files that are written to. Uploads files when found
     my $monitor = ns_systemFH('./inotifywait', '-r', '-m', '-e', 'close_write', '--format', '%w%f', $dir);
     while (<$monitor>) {
         chomp;
@@ -272,8 +300,8 @@ sub capture_packets {
 send_info();
 send_processes();
 
-# Files, logs, and commands to send to the server
 # ------------------------------------------------------------------------------
+# Files, logs, and commands to send to the server
 
 # These files will have their contents sent as they are updated
 send_log('/var/log/secure');