#ifndef _NF_OSF_H
#define _NF_OSF_H

#include <linux/types.h>
#include <linux/ip.h>
#include <linux/tcp.h>

#define MAXGENRELEN     32

#define NF_OSF_GENRE    (1 << 0)
#define NF_OSF_TTL      (1 << 1)
#define NF_OSF_LOG      (1 << 2)
#define NF_OSF_INVERT   (1 << 3)

#define NF_OSF_LOGLEVEL_ALL             0       /* log all matched fingerprints */
#define NF_OSF_LOGLEVEL_FIRST           1       /* log only the first matced fingerprint */
#define NF_OSF_LOGLEVEL_ALL_KNOWN       2       /* do not log unknown packets */

#define NF_OSF_TTL_TRUE                 0       /* True ip and fingerprint TTL comparison */

/* Check if ip TTL is less than fingerprint one */
#define NF_OSF_TTL_LESS                 1

/* Do not compare ip and fingerprint TTL at all */
#define NF_OSF_TTL_NOCHECK              2

#define NF_OSF_FLAGMASK         (NF_OSF_GENRE | NF_OSF_TTL | \
                                 NF_OSF_LOG | NF_OSF_INVERT)
/* Wildcard MSS (kind of).
 * It is used to implement a state machine for the different wildcard values
 * of the MSS and window sizes.
 */
struct nf_osf_wc {
        __u32   wc;
        __u32   val;
};

/* This struct represents IANA options
 * http://www.iana.org/assignments/tcp-parameters
 */
struct nf_osf_opt {
        __u16                   kind, length;
        struct nf_osf_wc        wc;
};

struct nf_osf_info {
        char    genre[MAXGENRELEN];
        __u32   len;
        __u32   flags;
        __u32   loglevel;
        __u32   ttl;
};

struct nf_osf_user_finger {
        struct nf_osf_wc        wss;

        __u8    ttl, df;
        __u16   ss, mss;
        __u16   opt_num;

        char    genre[MAXGENRELEN];
        char    version[MAXGENRELEN];
        char    subtype[MAXGENRELEN];

        /* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */
        struct nf_osf_opt       opt[MAX_IPOPTLEN];
};

struct nf_osf_nlmsg {
        struct nf_osf_user_finger       f;
        struct iphdr                    ip;
        struct tcphdr                   tcp;
};

/* Defines for IANA option kinds */
enum iana_options {
        OSFOPT_EOL = 0,         /* End of options */
        OSFOPT_NOP,             /* NOP */
        OSFOPT_MSS,             /* Maximum segment size */
        OSFOPT_WSO,             /* Window scale option */
        OSFOPT_SACKP,           /* SACK permitted */
        OSFOPT_SACK,            /* SACK */
        OSFOPT_ECHO,
        OSFOPT_ECHOREPLY,
        OSFOPT_TS,              /* Timestamp option */
        OSFOPT_POCP,            /* Partial Order Connection Permitted */
        OSFOPT_POSP,            /* Partial Order Service Profile */

        /* Others are not used in the current OSF */
        OSFOPT_EMPTY = 255,
};

/* Initial window size option state machine: multiple of mss, mtu or
 * plain numeric value. Can also be made as plain numeric value which
 * is not a multiple of specified value.
 */
enum nf_osf_window_size_options {
        OSF_WSS_PLAIN   = 0,
        OSF_WSS_MSS,
        OSF_WSS_MTU,
        OSF_WSS_MODULO,
        OSF_WSS_MAX,
};

enum nf_osf_attr_type {
        OSF_ATTR_UNSPEC,
        OSF_ATTR_FINGER,
        OSF_ATTR_MAX,
};

/*
 * Add/remove fingerprint from the kernel.
 */
enum nf_osf_msg_types {
        OSF_MSG_ADD,
        OSF_MSG_REMOVE,
        OSF_MSG_MAX,
};

#endif /* _NF_OSF_H */