From 97f941a4a561180e79859da40a9a8babca89ccea Mon Sep 17 00:00:00 2001
From: norly <ny-git@enpas.org>
Date: Sat, 11 Jun 2016 01:49:40 +0200
Subject: [PATCH] Initial commit

---
 Makefile |   3 ++
 vw-nm.c  | 159 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 162 insertions(+)
 create mode 100644 Makefile
 create mode 100644 vw-nm.c

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..1605cc0
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,3 @@
+CFLAGS += -Wall -g
+
+vw-nm:
diff --git a/vw-nm.c b/vw-nm.c
new file mode 100644
index 0000000..c3bf537
--- /dev/null
+++ b/vw-nm.c
@@ -0,0 +1,159 @@
+/*
+ * Copyright 2015 Max Staudt
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <linux/can.h>
+#include <linux/can/raw.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <endian.h>
+
+
+static int base_id = 0x420;
+static int my_id = 0x1a;
+static int next_id = 0x19;  //myid
+
+static int ignore_counter = 10;
+
+static void on_nm_frame(int socket)
+{
+  struct can_frame frame;
+  struct sockaddr_can addr;
+  int ret;
+  socklen_t len;
+
+  ret = recvfrom(socket, &frame, sizeof(struct can_frame), 0,
+                  (struct sockaddr *)&addr, &len);
+  if (ret < 0) {
+    perror("recvfrom");
+    exit(1);
+  }
+
+  if (frame.can_id >> 5 == 0x420 >> 5) {
+    printf("Received NM frame from %03x\n", frame.can_id);
+  }
+
+  if (frame.can_id == base_id + my_id) {
+    printf("Skipping my own NM frame.\n");
+    return;
+  }
+
+  switch (frame.data[1]) {
+    case 01:
+      if (frame.data[0] == my_id) {
+        struct can_frame txframe = {.can_id = base_id + next_id,
+                                    .can_dlc = 8,
+                                    .data = {next_id, 01, 00, 00, 00, 00, 00, 00},
+                                   };
+	ssize_t tmp = write(socket, &txframe, sizeof(txframe));
+	if (tmp != sizeof(txframe)) {
+		perror("write socket");
+		//return 1;
+	}
+      }
+      break;
+    case 02:
+      if (ignore_counter > 0) {
+        ignore_counter--;
+        break;
+      }
+      if (next_id <= my_id
+          ? frame.can_id - base_id < next_id
+          : next_id == my_id || frame.can_id - base_id < next_id) {
+        next_id = frame.can_id - base_id;
+
+        struct can_frame txframe = {.can_id = base_id + my_id,
+                                    .can_dlc = 8,
+                                    .data = {my_id, 02, 01, 04, 00, 04, 00, 00},
+                                   };
+	ssize_t tmp = write(socket, &txframe, sizeof(txframe));
+	if (tmp != sizeof(txframe)) {
+		perror("write socket");
+		//return 1;
+	}
+      }
+      break;
+  }
+}
+
+
+
+
+
+static int net_init(char *ifname)
+{
+        int s;
+	int recv_own_msgs;
+	struct sockaddr_can addr;
+	struct ifreq ifr;
+
+	s = socket(PF_CAN, SOCK_RAW, CAN_RAW);
+	if (s < 0) {
+		perror("socket");
+		exit(1);
+	}
+
+	memset(&ifr.ifr_name, 0, sizeof(ifr.ifr_name));
+	strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
+		perror("SIOCGIFINDEX");
+		exit(1);
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.can_family = AF_CAN;
+	addr.can_ifindex = ifr.ifr_ifindex;
+	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+		perror("bind");
+		return 0;
+	}
+
+	recv_own_msgs = 0; /* 0 = disabled (default), 1 = enabled */
+	setsockopt(s, SOL_CAN_RAW, CAN_RAW_RECV_OWN_MSGS,
+			&recv_own_msgs, sizeof(recv_own_msgs));
+
+	return s;
+}
+
+int main(int argc, char **argv)
+{
+  	fd_set rdfs;
+	int s;
+
+	if (argc != 2) {
+		printf("syntax: %s IFNAME\n", argv[0]);
+		exit(1);
+	}
+
+	s = net_init(argv[1]);
+
+	while (1) {
+
+		FD_ZERO(&rdfs);
+
+		FD_SET(s, &rdfs);
+
+		if (select(s+1, &rdfs, NULL, NULL, NULL) < 0) {
+			perror("select");
+			return 1;
+		}
+
+		if (FD_ISSET(s, &rdfs)) {
+			on_nm_frame(s);
+			continue;
+		}
+	}
+
+	return 0;
+}
-- 
2.30.2