From c4f5490abdd5ab7fcd6ed1dc24f29530663a9283 Mon Sep 17 00:00:00 2001
From: Dominik Meyer <dmeyer@federationhq.de>
Date: Tue, 26 Dec 2023 15:34:34 +0100
Subject: [PATCH] ADD: initial version of rcpt_mysql plugin

---
 plugins/rcpt_mysql | 232 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 232 insertions(+)
 create mode 100644 plugins/rcpt_mysql

diff --git a/plugins/rcpt_mysql b/plugins/rcpt_mysql
new file mode 100644
index 0000000..90d61a6
--- /dev/null
+++ b/plugins/rcpt_mysql
@@ -0,0 +1,232 @@
+use Qpsmtpd::Constants;
+use DBI;
+
+
+#
+# called when initializing the plugin 
+#
+sub init {
+    my ($self, $qp, %args) = @_;
+
+    # some default values
+    $self->{database} = "mail";
+    $self->{host} = "localhost";
+    $self->{port} = "3301";
+    $self->{user} = undef;
+    $self->{pass} = undef;
+    $self->{rawquery}= undef;
+
+    # the cache timeout in seconds
+    $self->{cacheTimeout} = 500; #seconds
+
+    # a map for caching database repsonses
+    # done on a per email basis
+    $self->{cache} = {};
+
+    # parse the configuration file
+    $self->parseConfig();
+
+    $self->createQuery();
+
+    $self->createDSN();
+}
+
+sub createDSN 
+{
+    my $self = shift;
+
+    my $dsn = "DBI:MariaDB:database=" . $self->{database} . ";host=" . $self->{host} . ";port=" . $self->{port};
+    $self->{dsn} = $dsn;
+   
+}
+
+sub createQuery
+{
+    my $self = shift;
+
+    #
+    # !u the user part of the rcpt
+    # !d the domain part of the rcpt
+
+    my @params;
+    my @variables = split /!/,$self->{rawquery};
+
+    for my $v (@variables)
+    {
+        if ($v eq "u")
+        {
+            push(@params,"user");
+        }
+        elsif ($v eq "d")
+        {
+            push(@params,"domain")
+        }
+    }
+
+    $self->{sqlparams}=\@params;
+
+    my $query = $self->{rawquery};
+    $query =~s/!u/?/g;
+    $query =~s/!d/?/g;
+
+    $self->{sqlquery}=$query;
+
+}
+
+sub prepareParams
+{
+    my $self = shift;
+    my $recipient = shift;
+
+    my @params;
+
+    for my $p (@params)
+    {
+        if ($p eq "user")
+        {
+            push(@params,$recipient->user);
+        }
+        elsif($p eq "domain")
+        {
+           push(@params,$recipient->user); 
+        }
+    }
+
+    return @params;
+}
+
+sub parseConfig 
+{
+    my $self = shift;
+
+    # parse the configuration file of this plugin line by line
+    my @config = $self->qp->config('rcpt_mysql');
+
+    for my $line (@config)
+    {
+        my @value = split /:=/, $line;
+
+        my $key = lc($value[0]);
+
+        if ( $key eq "database")
+        {
+            $self->{database} = $value[1];
+        }
+        elsif ( $key eq "host")
+        {
+            $self->{host} = $value[1];
+        }
+        elsif ( $key eq "user")
+        {
+            $self->{user} = $value[1];
+        }
+        elsif ( $key eq "pass")
+        {
+            $self->{pass} = $value[1];
+        }
+        elsif ( $key eq "port")
+        {
+            $self->{port} = $value[1];
+        }
+        elsif ( $key eq "cachetimeout")
+        {
+            $self->{cacheTimeout} = $value[1];
+        }
+        elsif ( $key eq "pass")
+        {
+            $self->{pass} = $value[1];
+        }
+        elsif ( $key eq "query")
+        {
+            $self->{rawquery} = $value[1];
+        }
+        else 
+        {
+            warn("Key \"" . $key . "\" is an unknown configuration option");
+        }
+
+    }
+
+}
+
+sub askCache 
+{
+    my $self      = shift;
+    my $recipient = shift;
+    
+    # combine to a normal recipient
+    my $rcpt = lc $recipient->user . '@' . lc $recipient->host;
+
+    # check if there is something in the cache for this recipient
+    if ($self->{cache}->{$rcpt} && $self->{cache}->{$rcpt}->{time}-time() <= $self->{cacheTimeout}) {
+        if ($self->{cache}->{$rcpt}->{hit} == 0 )
+        {
+            return DECLINED;
+        }
+        else 
+        {
+            return OK;
+        }
+    }
+
+    return undef;
+}
+
+sub askDatabase 
+{
+    my $self        = shift;
+    my $recipient   = shift;
+    my $dbh         = DBI::connect($self->{dsn}, $self->{user}, $self->{pass},{ RaiseError => 0, PrintError => 0 });
+
+    if ($dbh->err())
+    {
+        warn("error connecting to DB: " . $dbh->errstr());
+        return DENYSOFT;
+    }
+
+    my $sth = $dbh->prepare($self->{sqlquery});
+    if ($sth->err())
+    {
+        warn("error preparing query: " . $sth->errstr());
+        return DENYSOFT;
+    }
+
+    $sth->execute($self->prepareParams($recipient));
+
+    my $ret = DECLINED;
+
+    if ($sth->rows > 0)
+    {
+        $ret = OK;
+    }
+
+    return $ret;
+}
+
+#
+# plugin hook called if rcpt_to is issued within the smtp session
+#
+sub rcpt_to {
+    my ($self, $transaction, $recipient) = @_;
+
+    # some basic validations
+    return DECLINED unless $recipient->host && $recipient->user;
+
+    # ask the cache for results
+    my $cacheResult = $self->askCache($recipient);
+    return $cacheResult if defined($cacheResult);
+
+    # ask the database for results
+    return $self->askDatabase($recipient);    
+}
+
+#
+# called for registering all the hooks
+#
+sub register {
+    my ($self, $qp, %args) = @_;
+    
+    
+    $self->register_hook("rcpt", "rcpt_handler");
+    
+}