From 80a42e7896a9ddda3cc7f267861f2bcfa256c3d1 Mon Sep 17 00:00:00 2001
From: tyrolyean <tyrolyean@tyrolyean.net>
Date: Tue, 28 Apr 2020 23:31:18 +0200
Subject: [PATCH] Implement optarg and Readme update

Signed-off-by: tyrolyean <tyrolyean@tyrolyean.net>
---
 README           | 38 ++++++++++++++++++++++++++++---
 include/config.h |  4 +++-
 src/config.c     |  2 +-
 src/main.c       | 59 +++++++++++++++++++++++++++++++++++++++++++++---
 src/network.c    |  3 ---
 5 files changed, 95 insertions(+), 11 deletions(-)

diff --git a/README b/README
index 935db9e..a4c04fa 100644
--- a/README
+++ b/README
@@ -1,5 +1,37 @@
 MAILATTACH
 
-This program starts a process which listens on a unix socket for incoming
-milter connections. Incoming mail is scanned for large files and files above a
-certain threshold are replaced with links which the user may specify.
+This program starts a process which listens on the LOOPBACKv4 address for
+incoming connections from postfix. The postfix master should view this as an
+advanced filter as explained in their documentation for post queue filtering:
+
+http://www.postfix.org/FILTER_README.html
+
+The original attempt was to implement this as a pre queue filter, but this
+required the milter protocol and postfix currently does not implement the
+replace body function from libmilter.
+
+You can specify the following command line options:
+
+--abort-pgp --noabort-pgp
+	To either abort the attachment process if PGP encryption or signatures 
+	have been detected or not. If true, the mail will not be modified.
+
+--abort-dkim --noabort-dkim
+	To either abort the attachment process if DKIM signatures have been
+	detected or not. If true, the mail will not be modified.
+
+--in-port -i
+	The incoming smtp port/the port from which mail is received.
+
+--out-port -o
+	The outgoing smtp port/the port to which mail ist passed through.
+
+HOWTO
+
+We essentially are MITM sniffing your email traffic and playing proxy from your
+postfix to your postfix. That's how this is intended to work according to the
+postfix website.
+
+This program needs to be started via it's own systemd service on system boot.
+You need to add the in and oputput ports to your postfix queue as described in
+the link above. More documentation is to a TODO
diff --git a/include/config.h b/include/config.h
index b1aa220..adfd0b0 100644
--- a/include/config.h
+++ b/include/config.h
@@ -22,6 +22,8 @@
 
 extern uint16_t listen_port, forward_port;
 
-extern bool abort_on_pgp, abort_on_dkim;
+/* Used as booleans, but integers for getops sake... */
+
+extern int abort_on_pgp, abort_on_dkim;
 
 #endif /* CONFIG_H */
diff --git a/src/config.c b/src/config.c
index 9056020..7d62b30 100644
--- a/src/config.c
+++ b/src/config.c
@@ -17,4 +17,4 @@
 #include "config.h"
 
 uint16_t listen_port = 4269, forward_port = 4270;
-bool abort_on_pgp = true, abort_on_dkim = true;
+int abort_on_pgp = true, abort_on_dkim = true;
diff --git a/src/main.c b/src/main.c
index 7f34893..d51c9de 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,7 +6,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-
+#include <getopt.h>
 
 #include "network.h"
 #include "config.h"
@@ -15,11 +15,64 @@
 int main(int argc, char* argv[]){
 	
 	printf("INIT\n");
-	
+
+	int c;
+
+	while (1){
+		static struct option long_options[] =
+		{
+			{"abort-pgp",	no_argument, &abort_on_pgp, 1},
+			{"abort-dkim",	no_argument, &abort_on_dkim,1},
+			{"noabort-pgp",	no_argument, &abort_on_pgp, 0},
+			{"noabort-dkim",no_argument, &abort_on_dkim,0},
+			{"in-port",	required_argument, 0, 'i'},
+			{"out-port",	required_argument, 0, 'o'},
+			{0, 0, 0, 0}
+		};
+		/* getopt_long stores the option index here. */
+		int option_index = 0;
+
+		c = getopt_long (argc, argv, "i:o:pd",
+			       long_options, &option_index);
+
+		/* Detect the end of the options. */
+		if (c == -1){
+			break;
+		}
+
+		switch (c){
+		case 0:
+			break;
+		case 'i':
+			listen_port = atoi(optarg);
+			break;
+
+		case 'o':
+			forward_port = atoi(optarg);
+			break;
+
+		case '?':
+			/* getopt_long already printed an error message. */
+			return EXIT_FAILURE;
+			break;
+
+		default:
+			abort ();
+		}
+	}
+
+	printf("Incoming port: %u outgoing port: %u on loopback interface\n",
+		 listen_port, forward_port);
+	printf("Ignoring PGP signed/encrypted messages: %s\n",
+		abort_on_pgp ? "true":false);
+	printf("Ignoring DKIM signed messages: %s\n",
+		abort_on_dkim ? "true" : "false");
+
 	if(init_net() < 0){
 		return EXIT_FAILURE;
 	}
 
-
+	loop_clients();
+	return EXIT_SUCCESS;
 
 }
diff --git a/src/network.c b/src/network.c
index b5cbf61..e5d3e2f 100644
--- a/src/network.c
+++ b/src/network.c
@@ -273,9 +273,6 @@ void loop_clients(){
 	
 	while (1) {
 
-		/*
-		* accept: wait for a connection request
-		*/
 		childfd = accept(parentfd, (struct sockaddr *) &clientaddr, &clientlen);
 		if (childfd < 0){
 			perror("accept failed");