/* Copyright (C) 2007-2014 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, see <http://www.gnu.org/licenses/>.
 */

#ifndef _NET_BATMAN_ADV_MAIN_H_
#define _NET_BATMAN_ADV_MAIN_H_

#define BATADV_DRIVER_AUTHOR "Marek Lindner <mareklindner@neomailbox.ch>, " \
                             "Simon Wunderlich <sw@simonwunderlich.de>"
#define BATADV_DRIVER_DESC   "B.A.T.M.A.N. advanced"
#define BATADV_DRIVER_DEVICE "batman-adv"

#ifndef BATADV_SOURCE_VERSION
#define BATADV_SOURCE_VERSION "2015.0"
#endif

/* B.A.T.M.A.N. parameters */

#define BATADV_TQ_MAX_VALUE 255
#define BATADV_JITTER 20

/* Time To Live of broadcast messages */
#define BATADV_TTL 50

/* purge originators after time in seconds if no valid packet comes in
 * -> TODO: check influence on BATADV_TQ_LOCAL_WINDOW_SIZE
 */
#define BATADV_PURGE_TIMEOUT 200000 /* 200 seconds */
#define BATADV_TT_LOCAL_TIMEOUT 600000 /* in milliseconds */
#define BATADV_TT_CLIENT_ROAM_TIMEOUT 600000 /* in milliseconds */
#define BATADV_TT_CLIENT_TEMP_TIMEOUT 600000 /* in milliseconds */
#define BATADV_TT_WORK_PERIOD 5000 /* 5 seconds */
#define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */
#define BATADV_DAT_ENTRY_TIMEOUT (5*60000) /* 5 mins in milliseconds */
/* sliding packet range of received originator messages in sequence numbers
 * (should be a multiple of our word size)
 */
#define BATADV_TQ_LOCAL_WINDOW_SIZE 64
/* milliseconds we have to keep pending tt_req */
#define BATADV_TT_REQUEST_TIMEOUT 3000

#define BATADV_TQ_GLOBAL_WINDOW_SIZE 5
#define BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM 1
#define BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM 1
#define BATADV_TQ_TOTAL_BIDRECT_LIMIT 1

/* number of OGMs sent with the last tt diff */
#define BATADV_TT_OGM_APPEND_MAX 3

/* Time in which a client can roam at most ROAMING_MAX_COUNT times in
 * milliseconds
 */
#define BATADV_ROAMING_MAX_TIME 20000
#define BATADV_ROAMING_MAX_COUNT 5

#define BATADV_NO_FLAGS 0

#define BATADV_NULL_IFINDEX 0 /* dummy ifindex used to avoid iface checks */

#define BATADV_NO_MARK 0

/* default interface for multi interface operation. The default interface is
 * used for communication which originated locally (i.e. is not forwarded)
 * or where special forwarding is not desired/necessary.
 */
#define BATADV_IF_DEFAULT       ((struct batadv_hard_iface *)NULL)

#define BATADV_NUM_WORDS BITS_TO_LONGS(BATADV_TQ_LOCAL_WINDOW_SIZE)

#define BATADV_LOG_BUF_LEN 8192   /* has to be a power of 2 */

/* number of packets to send for broadcasts on different interface types */
#define BATADV_NUM_BCASTS_DEFAULT 1
#define BATADV_NUM_BCASTS_WIRELESS 3
#define BATADV_NUM_BCASTS_MAX 3

/* msecs after which an ARP_REQUEST is sent in broadcast as fallback */
#define ARP_REQ_DELAY 250
/* numbers of originator to contact for any PUT/GET DHT operation */
#define BATADV_DAT_CANDIDATES_NUM 3

/* BATADV_TQ_SIMILARITY_THRESHOLD - TQ points that a secondary metric can differ
 * at most from the primary one in order to be still considered acceptable
 */
#define BATADV_TQ_SIMILARITY_THRESHOLD 50

/* how much worse secondary interfaces may be to be considered as bonding
 * candidates
 */
#define BATADV_BONDING_TQ_THRESHOLD     50

/* should not be bigger than 512 bytes or change the size of
 * forw_packet->direct_link_flags
 */
#define BATADV_MAX_AGGREGATION_BYTES 512
#define BATADV_MAX_AGGREGATION_MS 100

#define BATADV_BLA_PERIOD_LENGTH        10000   /* 10 seconds */
#define BATADV_BLA_BACKBONE_TIMEOUT     (BATADV_BLA_PERIOD_LENGTH * 3)
#define BATADV_BLA_CLAIM_TIMEOUT        (BATADV_BLA_PERIOD_LENGTH * 10)
#define BATADV_BLA_WAIT_PERIODS         3

#define BATADV_DUPLIST_SIZE             16
#define BATADV_DUPLIST_TIMEOUT          500     /* 500 ms */
/* don't reset again within 30 seconds */
#define BATADV_RESET_PROTECTION_MS 30000
#define BATADV_EXPECTED_SEQNO_RANGE     65536

#define BATADV_NC_NODE_TIMEOUT 10000 /* Milliseconds */

enum batadv_mesh_state {
        BATADV_MESH_INACTIVE,
        BATADV_MESH_ACTIVE,
        BATADV_MESH_DEACTIVATING,
};

#define BATADV_BCAST_QUEUE_LEN          256
#define BATADV_BATMAN_QUEUE_LEN 256

enum batadv_uev_action {
        BATADV_UEV_ADD = 0,
        BATADV_UEV_DEL,
        BATADV_UEV_CHANGE,
};

enum batadv_uev_type {
        BATADV_UEV_GW = 0,
};

#define BATADV_GW_THRESHOLD     50

/* Number of fragment chains for each orig_node */
#define BATADV_FRAG_BUFFER_COUNT 8
/* Maximum number of fragments for one packet */
#define BATADV_FRAG_MAX_FRAGMENTS 16
/* Maxumim size of each fragment */
#define BATADV_FRAG_MAX_FRAG_SIZE 1400
/* Time to keep fragments while waiting for rest of the fragments */
#define BATADV_FRAG_TIMEOUT 10000

#define BATADV_DAT_CANDIDATE_NOT_FOUND  0
#define BATADV_DAT_CANDIDATE_ORIG       1

/* Debug Messages */
#ifdef pr_fmt
#undef pr_fmt
#endif
/* Append 'batman-adv: ' before kernel messages */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

/* Kernel headers */

#include <linux/mutex.h>        /* mutex */
#include <linux/module.h>       /* needed by all modules */
#include <linux/netdevice.h>    /* netdevice */
#include <linux/etherdevice.h>  /* ethernet address classification */
#include <linux/if_ether.h>     /* ethernet header */
#include <linux/poll.h>         /* poll_table */
#include <linux/kthread.h>      /* kernel threads */
#include <linux/pkt_sched.h>    /* schedule types */
#include <linux/workqueue.h>    /* workqueue */
#include <linux/percpu.h>
#include <linux/slab.h>
#include <net/sock.h>           /* struct sock */
#include <net/addrconf.h>       /* ipv6 address stuff */
#include <linux/ip.h>
#include <net/rtnetlink.h>
#include <linux/jiffies.h>
#include <linux/seq_file.h>
#include <linux/if_vlan.h>

#include "types.h"

#define BATADV_PRINT_VID(vid) (vid & BATADV_VLAN_HAS_TAG ? \
                               (int)(vid & VLAN_VID_MASK) : -1)

extern char batadv_routing_algo[];
extern struct list_head batadv_hardif_list;

extern unsigned char batadv_broadcast_addr[];
extern struct workqueue_struct *batadv_event_workqueue;

int batadv_mesh_init(struct net_device *soft_iface);
void batadv_mesh_free(struct net_device *soft_iface);
int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr);
struct batadv_hard_iface *
batadv_seq_print_text_primary_if_get(struct seq_file *seq);
int batadv_max_header_len(void);
void batadv_skb_set_priority(struct sk_buff *skb, int offset);
int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
                           struct packet_type *ptype,
                           struct net_device *orig_dev);
int
batadv_recv_handler_register(uint8_t packet_type,
                             int (*recv_handler)(struct sk_buff *,
                                                 struct batadv_hard_iface *));
void batadv_recv_handler_unregister(uint8_t packet_type);
int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops);
int batadv_algo_select(struct batadv_priv *bat_priv, char *name);
int batadv_algo_seq_print_text(struct seq_file *seq, void *offset);
__be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);

/**
 * enum batadv_dbg_level - available log levels
 * @BATADV_DBG_BATMAN: OGM and TQ computations related messages
 * @BATADV_DBG_ROUTES: route added / changed / deleted
 * @BATADV_DBG_TT: translation table messages
 * @BATADV_DBG_BLA: bridge loop avoidance messages
 * @BATADV_DBG_DAT: ARP snooping and DAT related messages
 * @BATADV_DBG_NC: network coding related messages
 * @BATADV_DBG_ALL: the union of all the above log levels
 */
enum batadv_dbg_level {
        BATADV_DBG_BATMAN = BIT(0),
        BATADV_DBG_ROUTES = BIT(1),
        BATADV_DBG_TT     = BIT(2),
        BATADV_DBG_BLA    = BIT(3),
        BATADV_DBG_DAT    = BIT(4),
        BATADV_DBG_NC     = BIT(5),
        BATADV_DBG_ALL    = 63,
};

#ifdef CONFIG_BATMAN_ADV_DEBUG
int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
__printf(2, 3);

/* possibly ratelimited debug output */
#define _batadv_dbg(type, bat_priv, ratelimited, fmt, arg...)   \
        do {                                                    \
                if (atomic_read(&bat_priv->log_level) & type && \
                    (!ratelimited || net_ratelimit()))          \
                        batadv_debug_log(bat_priv, fmt, ## arg);\
        }                                                       \
        while (0)
#else /* !CONFIG_BATMAN_ADV_DEBUG */
__printf(4, 5)
static inline void _batadv_dbg(int type __always_unused,
                               struct batadv_priv *bat_priv __always_unused,
                               int ratelimited __always_unused,
                               const char *fmt __always_unused, ...)
{
}
#endif

#define batadv_dbg(type, bat_priv, arg...) \
        _batadv_dbg(type, bat_priv, 0, ## arg)
#define batadv_dbg_ratelimited(type, bat_priv, arg...) \
        _batadv_dbg(type, bat_priv, 1, ## arg)

#define batadv_info(net_dev, fmt, arg...)                               \
        do {                                                            \
                struct net_device *_netdev = (net_dev);                 \
                struct batadv_priv *_batpriv = netdev_priv(_netdev);    \
                batadv_dbg(BATADV_DBG_ALL, _batpriv, fmt, ## arg);      \
                pr_info("%s: " fmt, _netdev->name, ## arg);             \
        } while (0)
#define batadv_err(net_dev, fmt, arg...)                                \
        do {                                                            \
                struct net_device *_netdev = (net_dev);                 \
                struct batadv_priv *_batpriv = netdev_priv(_netdev);    \
                batadv_dbg(BATADV_DBG_ALL, _batpriv, fmt, ## arg);      \
                pr_err("%s: " fmt, _netdev->name, ## arg);              \
        } while (0)

/* returns 1 if they are the same ethernet addr
 *
 * note: can't use ether_addr_equal() as it requires aligned memory
 */
static inline int batadv_compare_eth(const void *data1, const void *data2)
{
        return ether_addr_equal_unaligned(data1, data2);
}

/**
 * has_timed_out - compares current time (jiffies) and timestamp + timeout
 * @timestamp:          base value to compare with (in jiffies)
 * @timeout:            added to base value before comparing (in milliseconds)
 *
 * Returns true if current time is after timestamp + timeout
 */
static inline bool batadv_has_timed_out(unsigned long timestamp,
                                        unsigned int timeout)
{
        return time_is_before_jiffies(timestamp + msecs_to_jiffies(timeout));
}

#define batadv_atomic_dec_not_zero(v)   atomic_add_unless((v), -1, 0)

/* Returns the smallest signed integer in two's complement with the sizeof x */
#define batadv_smallest_signed_int(x) (1u << (7u + 8u * (sizeof(x) - 1u)))

/* Checks if a sequence number x is a predecessor/successor of y.
 * they handle overflows/underflows and can correctly check for a
 * predecessor/successor unless the variable sequence number has grown by
 * more then 2**(bitwidth(x)-1)-1.
 * This means that for a uint8_t with the maximum value 255, it would think:
 *  - when adding nothing - it is neither a predecessor nor a successor
 *  - before adding more than 127 to the starting value - it is a predecessor,
 *  - when adding 128 - it is neither a predecessor nor a successor,
 *  - after adding more than 127 to the starting value - it is a successor
 */
#define batadv_seq_before(x, y) ({typeof(x)_d1 = (x); \
                                 typeof(y)_d2 = (y); \
                                 typeof(x)_dummy = (_d1 - _d2); \
                                 (void)(&_d1 == &_d2); \
                                 _dummy > batadv_smallest_signed_int(_dummy); })
#define batadv_seq_after(x, y) batadv_seq_before(y, x)

/* Stop preemption on local cpu while incrementing the counter */
static inline void batadv_add_counter(struct batadv_priv *bat_priv, size_t idx,
                                      size_t count)
{
        this_cpu_add(bat_priv->bat_counters[idx], count);
}

#define batadv_inc_counter(b, i) batadv_add_counter(b, i, 1)

/* Sum and return the cpu-local counters for index 'idx' */
static inline uint64_t batadv_sum_counter(struct batadv_priv *bat_priv,
                                          size_t idx)
{
        uint64_t *counters, sum = 0;
        int cpu;

        for_each_possible_cpu(cpu) {
                counters = per_cpu_ptr(bat_priv->bat_counters, cpu);
                sum += counters[idx];
        }

        return sum;
}

/* Define a macro to reach the control buffer of the skb. The members of the
 * control buffer are defined in struct batadv_skb_cb in types.h.
 * The macro is inspired by the similar macro TCP_SKB_CB() in tcp.h.
 */
#define BATADV_SKB_CB(__skb)       ((struct batadv_skb_cb *)&((__skb)->cb[0]))

void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
                                    uint8_t type, uint8_t version,
                                    void *tvlv_value, uint16_t tvlv_value_len);
uint16_t batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
                                          unsigned char **packet_buff,
                                          int *packet_buff_len,
                                          int packet_min_len);
void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv,
                             struct batadv_ogm_packet *batadv_ogm_packet,
                             struct batadv_orig_node *orig_node);
void batadv_tvlv_container_unregister(struct batadv_priv *bat_priv,
                                      uint8_t type, uint8_t version);

void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
                                  void (*optr)(struct batadv_priv *bat_priv,
                                               struct batadv_orig_node *orig,
                                               uint8_t flags,
                                               void *tvlv_value,
                                               uint16_t tvlv_value_len),
                                  int (*uptr)(struct batadv_priv *bat_priv,
                                              uint8_t *src, uint8_t *dst,
                                              void *tvlv_value,
                                              uint16_t tvlv_value_len),
                                  uint8_t type, uint8_t version, uint8_t flags);
void batadv_tvlv_handler_unregister(struct batadv_priv *bat_priv,
                                    uint8_t type, uint8_t version);
int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
                                   bool ogm_source,
                                   struct batadv_orig_node *orig_node,
                                   uint8_t *src, uint8_t *dst,
                                   void *tvlv_buff, uint16_t tvlv_buff_len);
void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, uint8_t *src,
                              uint8_t *dst, uint8_t type, uint8_t version,
                              void *tvlv_value, uint16_t tvlv_value_len);
unsigned short batadv_get_vid(struct sk_buff *skb, size_t header_len);
bool batadv_vlan_ap_isola_get(struct batadv_priv *bat_priv, unsigned short vid);

#endif /* _NET_BATMAN_ADV_MAIN_H_ */