alistair23-linux/net/batman-adv/packet.h
Antonio Quartulli 30cfd02b60 batman-adv: detect not yet announced clients
With the current TT mechanism a new client joining the network is not
immediately able to communicate with other hosts because its MAC address has not
been announced yet. This situation holds until the first OGM containing its
joining event will be spread over the mesh network.

This behaviour can be acceptable in networks where the originator interval is a
small value (e.g. 1sec) but if that value is set to an higher time (e.g. 5secs)
the client could suffer from several malfunctions like DHCP client timeouts,
etc.

This patch adds an early detection mechanism that makes nodes in the network
able to recognise "not yet announced clients" by means of the broadcast packets
they emitted on connection (e.g. ARP or DHCP request). The added client will
then be confirmed upon receiving the OGM claiming it or purged if such OGM
is not received within a fixed amount of time.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-08-23 14:20:22 +02:00

230 lines
6 KiB
C

/* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#ifndef _NET_BATMAN_ADV_PACKET_H_
#define _NET_BATMAN_ADV_PACKET_H_
#define BATADV_ETH_P_BATMAN 0x4305 /* unofficial/not registered Ethertype */
enum batadv_packettype {
BATADV_IV_OGM = 0x01,
BATADV_ICMP = 0x02,
BATADV_UNICAST = 0x03,
BATADV_BCAST = 0x04,
BATADV_VIS = 0x05,
BATADV_UNICAST_FRAG = 0x06,
BATADV_TT_QUERY = 0x07,
BATADV_ROAM_ADV = 0x08,
};
/* this file is included by batctl which needs these defines */
#define BATADV_COMPAT_VERSION 14
enum batadv_iv_flags {
BATADV_NOT_BEST_NEXT_HOP = BIT(3),
BATADV_PRIMARIES_FIRST_HOP = BIT(4),
BATADV_VIS_SERVER = BIT(5),
BATADV_DIRECTLINK = BIT(6),
};
/* ICMP message types */
enum batadv_icmp_packettype {
BATADV_ECHO_REPLY = 0,
BATADV_DESTINATION_UNREACHABLE = 3,
BATADV_ECHO_REQUEST = 8,
BATADV_TTL_EXCEEDED = 11,
BATADV_PARAMETER_PROBLEM = 12,
};
/* vis defines */
enum batadv_vis_packettype {
BATADV_VIS_TYPE_SERVER_SYNC = 0,
BATADV_VIS_TYPE_CLIENT_UPDATE = 1,
};
/* fragmentation defines */
enum batadv_unicast_frag_flags {
BATADV_UNI_FRAG_HEAD = BIT(0),
BATADV_UNI_FRAG_LARGETAIL = BIT(1),
};
/* TT_QUERY subtypes */
#define BATADV_TT_QUERY_TYPE_MASK 0x3
enum batadv_tt_query_packettype {
BATADV_TT_REQUEST = 0,
BATADV_TT_RESPONSE = 1,
};
/* TT_QUERY flags */
enum batadv_tt_query_flags {
BATADV_TT_FULL_TABLE = BIT(2),
};
/* BATADV_TT_CLIENT flags.
* Flags from BIT(0) to BIT(7) are sent on the wire, while flags from BIT(8) to
* BIT(15) are used for local computation only
*/
enum batadv_tt_client_flags {
BATADV_TT_CLIENT_DEL = BIT(0),
BATADV_TT_CLIENT_ROAM = BIT(1),
BATADV_TT_CLIENT_WIFI = BIT(2),
BATADV_TT_CLIENT_TEMP = BIT(3),
BATADV_TT_CLIENT_NOPURGE = BIT(8),
BATADV_TT_CLIENT_NEW = BIT(9),
BATADV_TT_CLIENT_PENDING = BIT(10),
};
/* claim frame types for the bridge loop avoidance */
enum batadv_bla_claimframe {
BATADV_CLAIM_TYPE_CLAIM = 0x00,
BATADV_CLAIM_TYPE_UNCLAIM = 0x01,
BATADV_CLAIM_TYPE_ANNOUNCE = 0x02,
BATADV_CLAIM_TYPE_REQUEST = 0x03,
};
/* the destination hardware field in the ARP frame is used to
* transport the claim type and the group id
*/
struct batadv_bla_claim_dst {
uint8_t magic[3]; /* FF:43:05 */
uint8_t type; /* bla_claimframe */
__be16 group; /* group id */
} __packed;
struct batadv_header {
uint8_t packet_type;
uint8_t version; /* batman version field */
uint8_t ttl;
} __packed;
struct batadv_ogm_packet {
struct batadv_header header;
uint8_t flags; /* 0x40: DIRECTLINK flag, 0x20 VIS_SERVER flag... */
__be32 seqno;
uint8_t orig[ETH_ALEN];
uint8_t prev_sender[ETH_ALEN];
uint8_t gw_flags; /* flags related to gateway class */
uint8_t tq;
uint8_t tt_num_changes;
uint8_t ttvn; /* translation table version number */
__be16 tt_crc;
} __packed;
#define BATADV_OGM_HLEN sizeof(struct batadv_ogm_packet)
struct batadv_icmp_packet {
struct batadv_header header;
uint8_t msg_type; /* see ICMP message types above */
uint8_t dst[ETH_ALEN];
uint8_t orig[ETH_ALEN];
__be16 seqno;
uint8_t uid;
uint8_t reserved;
} __packed;
#define BATADV_RR_LEN 16
/* icmp_packet_rr must start with all fields from imcp_packet
* as this is assumed by code that handles ICMP packets
*/
struct batadv_icmp_packet_rr {
struct batadv_header header;
uint8_t msg_type; /* see ICMP message types above */
uint8_t dst[ETH_ALEN];
uint8_t orig[ETH_ALEN];
__be16 seqno;
uint8_t uid;
uint8_t rr_cur;
uint8_t rr[BATADV_RR_LEN][ETH_ALEN];
} __packed;
struct batadv_unicast_packet {
struct batadv_header header;
uint8_t ttvn; /* destination translation table version number */
uint8_t dest[ETH_ALEN];
} __packed;
struct batadv_unicast_frag_packet {
struct batadv_header header;
uint8_t ttvn; /* destination translation table version number */
uint8_t dest[ETH_ALEN];
uint8_t flags;
uint8_t align;
uint8_t orig[ETH_ALEN];
__be16 seqno;
} __packed;
struct batadv_bcast_packet {
struct batadv_header header;
uint8_t reserved;
__be32 seqno;
uint8_t orig[ETH_ALEN];
} __packed;
struct batadv_vis_packet {
struct batadv_header header;
uint8_t vis_type; /* which type of vis-participant sent this? */
__be32 seqno; /* sequence number */
uint8_t entries; /* number of entries behind this struct */
uint8_t reserved;
uint8_t vis_orig[ETH_ALEN]; /* originator reporting its neighbors */
uint8_t target_orig[ETH_ALEN]; /* who should receive this packet */
uint8_t sender_orig[ETH_ALEN]; /* who sent or forwarded this packet */
} __packed;
struct batadv_tt_query_packet {
struct batadv_header header;
/* the flag field is a combination of:
* - TT_REQUEST or TT_RESPONSE
* - TT_FULL_TABLE
*/
uint8_t flags;
uint8_t dst[ETH_ALEN];
uint8_t src[ETH_ALEN];
/* the ttvn field is:
* if TT_REQUEST: ttvn that triggered the
* request
* if TT_RESPONSE: new ttvn for the src
* orig_node
*/
uint8_t ttvn;
/* tt_data field is:
* if TT_REQUEST: crc associated with the
* ttvn
* if TT_RESPONSE: table_size
*/
__be16 tt_data;
} __packed;
struct batadv_roam_adv_packet {
struct batadv_header header;
uint8_t reserved;
uint8_t dst[ETH_ALEN];
uint8_t src[ETH_ALEN];
uint8_t client[ETH_ALEN];
} __packed;
struct batadv_tt_change {
uint8_t flags;
uint8_t addr[ETH_ALEN];
} __packed;
#endif /* _NET_BATMAN_ADV_PACKET_H_ */