[PATCH 0/3] batctl: tcpdump: Add support to identify missing packets

[PATCH 0/3] batctl: tcpdump: Add support to identify missing packets

[Sven Eckelmann]

Hi,

when running batctl's tcpdump today on a normal batman-adv slave interface,
you will see warnings like:

  Warning - packet contains unknown batman packet type: 0x41
  Warning - packet contains unknown batman packet type: 0x02

This is caused by missing dumping routinges in the tcpdump implementation.
Since these packets (coded, fragmented) cannot be decoded/reassembled
easily these packets are only identified and some basic header informations
are shown.

Also not all TVLVs in the header were shown. The mcast part was dropped and
thus the debugging of the new mcast feature flags was not possible with
batctl.

Kind regards,
	Sven

Sven Eckelmann (3):
  batctl: tcpdump: Add support for MCAST TVLV
  batctl: tcpdump: Add support for unicast fragmentation
  batctl: tcpdump: Add support for coded packets

 tcpdump.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 tcpdump.h |   1 +
 2 files changed, 110 insertions(+), 1 deletion(-)

-- 
2.20.1

[PATCH 1/3] batctl: tcpdump: Add support for MCAST TVLV

[Sven Eckelmann]

The multicast support in batman-adv was introduced in commit 77ec494490d6
("batman-adv: Announce new capability via multicast TVLV") but the tcpdump
parser was not updated to parse this TVLV container.

The parser requires support of parsing the current TVLV container (v2) and
the pre-bridging implementation (v1) to correctly show all TVLVs of OGMs
(and related packets).

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
Cc: Linus Lüssing <linus.luessing@c0d3.blue>

 tcpdump.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/tcpdump.c b/tcpdump.c
index 8106a64..9153fc4 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -196,6 +196,45 @@ static void batctl_tvlv_parse_roam_v1(void *buff, ssize_t buff_len)
 	       BATADV_PRINT_VID(ntohs(tvlv->vid)));
 }
 
+static void batctl_tvlv_parse_mcast_v1(void *buff __maybe_unused,
+				       ssize_t buff_len)
+{
+	struct batadv_tvlv_mcast_data *tvlv = buff;
+	uint8_t flags;
+
+	if (buff_len != sizeof(*tvlv)) {
+		fprintf(stderr, "Warning - dropping received %s packet as it is not the correct size (%zu): %zu\n",
+			"TVLV MCASTv1", sizeof(*tvlv), buff_len);
+		return;
+	}
+
+	flags = tvlv->flags;
+
+	printf("\tTVLV MCASTv1: [%c%c%c]\n",
+	       flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES ? 'U' : '.',
+	       flags & BATADV_MCAST_WANT_ALL_IPV4 ? '4' : '.',
+	       flags & BATADV_MCAST_WANT_ALL_IPV6 ? '6' : '.');
+}
+
+static void batctl_tvlv_parse_mcast_v2(void *buff, ssize_t buff_len)
+{
+	struct batadv_tvlv_mcast_data *tvlv = buff;
+	uint8_t flags;
+
+	if (buff_len != sizeof(*tvlv)) {
+		fprintf(stderr, "Warning - dropping received %s packet as it is not the correct size (%zu): %zu\n",
+			"TVLV MCASTv2", sizeof(*tvlv), buff_len);
+		return;
+	}
+
+	flags = tvlv->flags;
+
+	printf("\tTVLV MCASTv2: [%c%c%c]\n",
+	       flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES ? 'U' : '.',
+	       flags & BATADV_MCAST_WANT_ALL_IPV4 ? '4' : '.',
+	       flags & BATADV_MCAST_WANT_ALL_IPV6 ? '6' : '.');
+}
+
 typedef void (*batctl_tvlv_parser_t)(void *buff, ssize_t buff_len);
 
 static batctl_tvlv_parser_t tvlv_parser_get(uint8_t type, uint8_t version)
@@ -241,6 +280,16 @@ static batctl_tvlv_parser_t tvlv_parser_get(uint8_t type, uint8_t version)
 			return NULL;
 		}
 
+	case BATADV_TVLV_MCAST:
+		switch (version) {
+		case 1:
+			return batctl_tvlv_parse_mcast_v1;
+		case 2:
+			return batctl_tvlv_parse_mcast_v2;
+		default:
+			return NULL;
+		}
+
 	default:
 		return NULL;
 	}
-- 
2.20.1

[PATCH 2/3] batctl: tcpdump: Add support for unicast fragmentation

[Sven Eckelmann]

The support for unicast fragmentation was implemented in commit
9b3eab61754d ("batman-adv: Receive fragmented packets and merge"). The
support to identify such packets by batctl's tcpdump was never implemented.

This minimal implementation allows to identify these packets but is not
able to reassemble the packets. Wireshark should be used when this advanced
feature is required.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
Cc: Martin Hundebøll <martin@hundeboll.net>

 tcpdump.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/tcpdump.c b/tcpdump.c
index 9153fc4..7d04dd5 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -930,6 +930,30 @@ static void dump_batman_ucast(unsigned char *packet_buff, ssize_t buff_len, int
 		      read_opt, time_printed);
 }
 
+static void dump_batman_ucast_frag(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed)
+{
+	struct batadv_frag_packet *frag_packet;
+	struct ether_header *ether_header;
+
+	LEN_CHECK((size_t)buff_len - sizeof(*ether_header),
+		  sizeof(*frag_packet), "BAT UCAST FRAG");
+
+	ether_header = (struct ether_header *)packet_buff;
+	frag_packet = (struct batadv_frag_packet *)(packet_buff + sizeof(*ether_header));
+
+	if (!time_printed)
+		time_printed = print_time();
+
+	printf("BAT %s > ",
+	       get_name_by_macaddr((struct ether_addr *)ether_header->ether_shost,
+				   read_opt));
+
+	printf("%s: UCAST FRAG, seqno %d, no %d, ttl %hhu\n",
+	       get_name_by_macaddr((struct ether_addr *)frag_packet->dest,
+				   read_opt),
+	       frag_packet->seqno, frag_packet->no, frag_packet->ttl);
+}
+
 static void dump_batman_bcast(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed)
 {
 	struct ether_header *ether_header;
@@ -1041,6 +1065,10 @@ static void parse_eth_hdr(unsigned char *packet_buff, ssize_t buff_len, int read
 			if (dump_level & DUMP_TYPE_BATUCAST)
 				dump_batman_ucast(packet_buff, buff_len, read_opt, time_printed);
 			break;
+		case BATADV_UNICAST_FRAG:
+			if (dump_level & DUMP_TYPE_BATFRAG)
+				dump_batman_ucast_frag(packet_buff, buff_len, read_opt, time_printed);
+			break;
 		case BATADV_BCAST:
 			if (dump_level & DUMP_TYPE_BATBCAST)
 				dump_batman_bcast(packet_buff, buff_len, read_opt, time_printed);
-- 
2.20.1

[PATCH 3/3] batctl: tcpdump: Add support for coded packets

[Sven Eckelmann]

The network coding support in batman-adv was introduced with commit
c3289f3650d3 ("batman-adv: network coding - code and transmit packets if
possible"). The support to identify such packets by batctl's tcpdump was
never implemented.

This minimal implementation allows to identify these packets but is not
able to decode the packets.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
Cc: Martin Hundebøll <martin@hundeboll.net>

 tcpdump.c | 33 ++++++++++++++++++++++++++++++++-
 tcpdump.h |  1 +
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/tcpdump.c b/tcpdump.c
index 7d04dd5..158b82e 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -56,7 +56,7 @@ static unsigned short dump_level_all = DUMP_TYPE_BATOGM | DUMP_TYPE_BATOGM2 |
 				       DUMP_TYPE_BATELP | DUMP_TYPE_BATICMP |
 				       DUMP_TYPE_BATUCAST | DUMP_TYPE_BATBCAST |
 				       DUMP_TYPE_BATUTVLV | DUMP_TYPE_BATFRAG |
-				       DUMP_TYPE_NONBAT;
+				       DUMP_TYPE_NONBAT | DUMP_TYPE_BATCODED;
 static unsigned short dump_level;
 
 static void parse_eth_hdr(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed);
@@ -80,6 +80,7 @@ static void tcpdump_usage(void)
 	fprintf(stderr, " \t\t%3d - batman fragmented packets\n", DUMP_TYPE_BATFRAG);
 	fprintf(stderr, " \t\t%3d - batman unicast tvlv packets\n", DUMP_TYPE_BATUTVLV);
 	fprintf(stderr, " \t\t%3d - non batman packets\n", DUMP_TYPE_NONBAT);
+	fprintf(stderr, " \t\t%3d - batman coded packets\n", DUMP_TYPE_BATCODED);
 	fprintf(stderr, " \t\t%3d - batman ogm & non batman packets\n", DUMP_TYPE_BATOGM | DUMP_TYPE_NONBAT);
 }
 
@@ -981,6 +982,32 @@ static void dump_batman_bcast(unsigned char *packet_buff, ssize_t buff_len, int
 		      read_opt, time_printed);
 }
 
+static void dump_batman_coded(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed)
+{
+	struct batadv_coded_packet *coded_packet;
+	struct ether_header *ether_header;
+
+	LEN_CHECK((size_t)buff_len - sizeof(*ether_header), sizeof(*coded_packet), "BAT CODED");
+
+	ether_header = (struct ether_header *)packet_buff;
+	coded_packet = (struct batadv_coded_packet *)(packet_buff + sizeof(*ether_header));
+
+	if (!time_printed)
+		time_printed = print_time();
+
+	printf("BAT %s > ",
+	       get_name_by_macaddr((struct ether_addr *)ether_header->ether_shost,
+				   read_opt));
+
+	printf("%s|%s: CODED, ttvn %d|%d, ttl %hhu\n",
+	       get_name_by_macaddr((struct ether_addr *)coded_packet->first_orig_dest,
+				   read_opt),
+	       get_name_by_macaddr((struct ether_addr *)coded_packet->second_dest,
+				   read_opt),
+	       coded_packet->first_ttvn, coded_packet->second_ttvn,
+	       coded_packet->ttl);
+}
+
 static void dump_batman_4addr(unsigned char *packet_buff, ssize_t buff_len, int read_opt, int time_printed)
 {
 	struct ether_header *ether_header;
@@ -1073,6 +1100,10 @@ static void parse_eth_hdr(unsigned char *packet_buff, ssize_t buff_len, int read
 			if (dump_level & DUMP_TYPE_BATBCAST)
 				dump_batman_bcast(packet_buff, buff_len, read_opt, time_printed);
 			break;
+		case BATADV_CODED:
+			if (dump_level & DUMP_TYPE_BATCODED)
+				dump_batman_coded(packet_buff, buff_len, read_opt, time_printed);
+			break;
 		case BATADV_UNICAST_4ADDR:
 			if (dump_level & DUMP_TYPE_BATUCAST)
 				dump_batman_4addr(packet_buff, buff_len, read_opt, time_printed);
diff --git a/tcpdump.h b/tcpdump.h
index 6e9ae01..470b96a 100644
--- a/tcpdump.h
+++ b/tcpdump.h
@@ -33,6 +33,7 @@
 #define DUMP_TYPE_BATUTVLV 64
 #define DUMP_TYPE_BATFRAG 128
 #define DUMP_TYPE_NONBAT 256
+#define DUMP_TYPE_BATCODED 512
 
 #define IEEE80211_FCTL_FTYPE 0x0c00
 #define IEEE80211_FCTL_TODS 0x0001
-- 
2.20.1