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; }

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