From 0524358cef990482f4c1ccdde320ab9ad0309255 Mon Sep 17 00:00:00 2001
From: tyrolyean <tyrolyean@tyrolyean.net>
Date: Wed, 29 Apr 2020 00:08:34 +0200
Subject: [PATCH] Added instance id option to mark messages

Signed-off-by: tyrolyean <tyrolyean@tyrolyean.net>
---
 include/config.h |  2 ++
 src/config.c     |  4 ++++
 src/detect.c     |  1 +
 src/main.c       | 24 +++++++++++++++++++++++-
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/include/config.h b/include/config.h
index adfd0b0..7ceb29a 100644
--- a/include/config.h
+++ b/include/config.h
@@ -26,4 +26,6 @@ extern uint16_t listen_port, forward_port;
 
 extern int abort_on_pgp, abort_on_dkim;
 
+extern char* instance_id;
+
 #endif /* CONFIG_H */
diff --git a/src/config.c b/src/config.c
index 7d62b30..8cb4876 100644
--- a/src/config.c
+++ b/src/config.c
@@ -14,7 +14,11 @@
  * specific language governing permissions and limitations
  * under the License.
  */
+
 #include "config.h"
 
+#include <stddef.h>
+
 uint16_t listen_port = 4269, forward_port = 4270;
 int abort_on_pgp = true, abort_on_dkim = true;
+char* instance_id = NULL;
diff --git a/src/detect.c b/src/detect.c
index bcf96cc..61fea86 100644
--- a/src/detect.c
+++ b/src/detect.c
@@ -58,6 +58,7 @@ bool detect_dkim(struct email_t* mail){
 		if(strcasestr(mail->message, dkim_signatures[i]) != NULL
 				&& strcasestr(mail->message, dkim_signatures[i])
 				<= (mail->message+mail->header_len)){
+			/* DKIM only happens inside the header, not the body! */
 			points++;
 		}
 		
diff --git a/src/main.c b/src/main.c
index 99bdd72..aed82fd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -7,6 +7,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <getopt.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
 
 #include "network.h"
 #include "config.h"
@@ -27,12 +30,13 @@ int main(int argc, char* argv[]){
 			{"noabort-dkim",no_argument, &abort_on_dkim,0},
 			{"in-port",	required_argument, 0, 'i'},
 			{"out-port",	required_argument, 0, 'o'},
+			{"instance-id",	required_argument, 0, 'n'},
 			{0, 0, 0, 0}
 		};
 		/* getopt_long stores the option index here. */
 		int option_index = 0;
 
-		c = getopt_long (argc, argv, "i:o:pd",
+		c = getopt_long (argc, argv, "n:i:o:pd",
 			       long_options, &option_index);
 
 		/* Detect the end of the options. */
@@ -50,6 +54,10 @@ int main(int argc, char* argv[]){
 		case 'o':
 			forward_port = atoi(optarg);
 			break;
+			
+		case 'n':
+			instance_id = optarg;
+			break;
 
 		case '?':
 			/* getopt_long already printed an error message. */
@@ -61,6 +69,17 @@ int main(int argc, char* argv[]){
 		}
 	}
 
+	/* If not already specified, populate the instance ID with the sytem 
+	 * hostname.
+	 */
+	if(instance_id == NULL){
+		instance_id = malloc(HOST_NAME_MAX + 1);
+		memset(instance_id, 0, HOST_NAME_MAX + 1);
+		if(gethostname(instance_id, HOST_NAME_MAX) < 0){
+			perror("gethostname failed! set instance id manually");
+		}
+	}
+
 	printf("Incoming port: %u outgoing port: %u on loopback interface\n",
 		 listen_port, forward_port);
 
@@ -69,6 +88,9 @@ int main(int argc, char* argv[]){
 
 	printf("Ignoring DKIM signed messages: %s\n",
 		abort_on_dkim ? "true" : "false");
+	
+	printf("Instance id for messages: %s\n",
+		instance_id);
 
 	if(init_net() < 0){
 		return EXIT_FAILURE;