Add vw-bap-sniffer

3 files changed, 193 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 0ff3668..5b235d5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,9 @@
 CFLAGS += -Wall -g
 
+all: vw-bap-dump vw-bap-sniffer
+
+
 vw-bap-dump: vw-bap-dump.c vw-bap.c
+
+vw-bap-sniffer: vw-bap-sniffer.c vw-bap.c
+	gcc -o $@ $^ -lncurses
diff --git a/vw-bap-sniffer.c b/vw-bap-sniffer.c
new file mode 100644
index 0000000..3639a07
--- /dev/null
+++ b/vw-bap-sniffer.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2017 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 <ncurses.h>
+
+#include "vw-bap.h"
+
+
+
+
+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);
+	}
+
+	/* Convert interface name to index */
+	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);
+	}
+
+	/* Open the CAN interface */
+	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 = 1; /* 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;
+	unsigned can_id;
+	struct BAP_RXer *bap;
+	unsigned sub_node_id;
+
+	if (argc < 4) {
+		printf("syntax: %s IFNAME CAN_ID SubNode \n", argv[0]);
+		return 1;
+	}
+
+	can_id = strtoul(argv[2], NULL, 0);
+	sub_node_id = strtoul(argv[3], NULL, 0);
+
+	bap = vw_bap_alloc();
+	if (!bap) {
+		printf("Out of memory allocating BAP struct.\n");
+		return 1;
+	}
+
+	printf("Listening for CAN ID: %x and SubNode %d\n", can_id, sub_node_id);
+
+
+
+	s = net_init(argv[1]);
+
+
+	initscr();
+
+
+	while (1) {
+		int retval;
+
+		FD_ZERO(&rdfs);
+		FD_SET(s, &rdfs);
+
+		retval = select(s+1, &rdfs, NULL, NULL, NULL);
+		/* We currently rely on Linux timeout behavior here,
+		 * i.e. the timeout now reflects the remaining time */
+		if (retval < 0) {
+			perror("select");
+			return 1;
+		} else if (!retval) {
+			/* Timeout, we NEED to check this first */
+		} else if (FD_ISSET(s, &rdfs)) {
+			struct can_frame frame;
+			ssize_t ret;
+
+			ret = read(s, &frame, sizeof(frame));
+			if (ret < 0) {
+				perror("read from CAN socket");
+				return 1;
+			}
+
+			if (can_id == frame.can_id) {
+				struct BAP_Frame *bap_frame;
+				unsigned i;
+
+				bap_frame = vw_bap_handle_can_frame(bap, &frame);
+				if (bap_frame && bap_frame->subnode == sub_node_id) {
+					mvprintw(bap_frame->function, 0, "");
+
+					printw("%u. %2i/%-2i .%02i --",
+						bap_frame->opcode,
+						bap_frame->subnode,
+						bap_frame->function,
+						bap_frame->len);
+
+					/* Limit huge packets */
+					if (bap_frame->len > 20) {
+						bap_frame->len = 20;
+					}
+
+					/* Hex dump */
+					for (i = 0; i < bap_frame->len; i++) {
+						if (!(i % 4)) {
+							printw(" ");
+						}
+						printw("%02x", (unsigned char)(bap_frame->data[i]));
+					}
+
+					printw("\n");
+
+					/* ASCII dump */
+					mvprintw(bap_frame->function, 64, "");
+					for (i = 0; i < bap_frame->len; i++) {
+						unsigned char c = bap_frame->data[i];
+						if (!isprint(c) || c == '\n' || c == '\r') {
+							c = '.';
+						}
+						printw("%c", c);
+					}
+					printw("'");
+					printw("\n");
+
+					refresh();
+
+					vw_bap_frame_free(bap_frame);
+				}
+			}
+
+			continue;
+		}
+	}
+
+	endwin();
+
+	vw_bap_free(bap);
+
+	close(s);
+
+	return 0;
+}
diff --git a/vw-bap.h b/vw-bap.h
index 00c9b75..5485138 100644
--- a/vw-bap.h
+++ b/vw-bap.h
@@ -11,6 +11,7 @@ typedef unsigned short BAP_FrameLen;
 
 
 struct BAP_Frame {
+	/* True if frame was/will be transmitted in multi-frame syntax */
 	int is_multiframe;
 
 	BAP_OpCode opcode;
@@ -23,7 +24,10 @@ struct BAP_Frame {
 
 
 struct BAP_RXer {
+	/* Temporary storage for incomplete frames */
 	struct BAP_Frame *mfchannel[8];
+
+	/* How many bytes have we already received on each channel? */
 	BAP_FrameLen len_done[8];
 };