/*
 * Copyright (C) 2012 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 * Id: ip_proxy.h,v 2.31.2.2 2005/03/12 19:33:48 darrenr Exp
 */

#ifndef __IP_PROXY_H__
#define __IP_PROXY_H__

#ifndef SOLARIS
# if defined(sun) && defined(__SVR4)
#  define       SOLARIS         1
# else
#  define       SOLARIS         0
# endif
#endif

#define SIOCPROXY       _IOWR('r', 64, struct ap_control)

#ifndef APR_LABELLEN
#define APR_LABELLEN    16
#endif
#define AP_SESS_SIZE    53

struct  nat;
struct  ipnat;
struct  ipstate;

typedef struct  ap_tcp {
        u_short apt_sport;      /* source port */
        u_short apt_dport;      /* destination port */
        short   apt_sel[2];     /* {seq,ack}{off,min} set selector */
        short   apt_seqoff[2];  /* sequence # difference */
        u_32_t  apt_seqmin[2];  /* don't change seq-off until after this */
        short   apt_ackoff[2];  /* sequence # difference */
        u_32_t  apt_ackmin[2];  /* don't change seq-off until after this */
        u_char  apt_state[2];   /* connection state */
} ap_tcp_t;

typedef struct  ap_udp {
        u_short apu_sport;      /* source port */
        u_short apu_dport;      /* destination port */
} ap_udp_t;

typedef struct ap_session {
        struct  aproxy  *aps_apr;
        union {
                struct  ap_tcp  apu_tcp;
                struct  ap_udp  apu_udp;
        } aps_un;
        U_QUAD_T aps_bytes;     /* bytes sent */
        U_QUAD_T aps_pkts;      /* packets sent */
        void    *aps_nat;       /* pointer back to nat struct */
        void    *aps_data;      /* private data */
        int     aps_psiz;       /* size of private data */
        struct  ap_session      *aps_next;
} ap_session_t;

#define aps_sport       aps_un.apu_tcp.apt_sport
#define aps_dport       aps_un.apu_tcp.apt_dport
#define aps_sel         aps_un.apu_tcp.apt_sel
#define aps_seqoff      aps_un.apu_tcp.apt_seqoff
#define aps_seqmin      aps_un.apu_tcp.apt_seqmin
#define aps_state       aps_un.apu_tcp.apt_state
#define aps_ackoff      aps_un.apu_tcp.apt_ackoff
#define aps_ackmin      aps_un.apu_tcp.apt_ackmin


typedef struct  ap_control {
        char    apc_label[APR_LABELLEN];
        char    apc_config[APR_LABELLEN];
        u_char  apc_p;
        /*
         * The following fields are upto the proxy's apr_ctl routine to deal
         * with.  When the proxy gets this in kernel space, apc_data will
         * point to a malloc'd region of memory of apc_dsize bytes.  If the
         * proxy wants to keep that memory, it must set apc_data to NULL
         * before it returns.  It is expected if this happens that it will
         * take care to free it in apr_fini or otherwise as appropriate.
         * apc_cmd is provided as a standard place to put simple commands,
         * with apc_arg being available to put a simple arg.
         */
        u_long  apc_cmd;
        u_long  apc_arg;
        void    *apc_data;
        size_t  apc_dsize;
} ap_ctl_t;

#define APC_CMD_ADD     0
#define APC_CMD_DEL     1


typedef struct  aproxy  {
        struct  aproxy  *apr_next;
        struct  aproxy  *apr_parent;
        char    apr_label[APR_LABELLEN];        /* Proxy label # */
        u_char  apr_p;                          /* protocol */
        int     apr_flags;
        int     apr_ref;
        int     apr_clones;
        void    (* apr_load)(void);
        void    (* apr_unload)(void);
        void    *(* apr_create)(ipf_main_softc_t *);
        void    (* apr_destroy)(ipf_main_softc_t *, void *);
        int     (* apr_init)(ipf_main_softc_t *, void *);
        void    (* apr_fini)(ipf_main_softc_t *, void *);
        int     (* apr_new)(void *, fr_info_t *, ap_session_t *,
                                 struct nat *);
        void    (* apr_del)(ipf_main_softc_t *, ap_session_t *);
        int     (* apr_inpkt)(void *, fr_info_t *, ap_session_t *,
                                   struct nat *);
        int     (* apr_outpkt)(void *, fr_info_t *, ap_session_t *,
                                    struct nat *);
        int     (* apr_match)(fr_info_t *, ap_session_t *, struct nat *);
        int     (* apr_ctl)(ipf_main_softc_t *, void *, ap_ctl_t *);
        int     (* apr_clear)(struct aproxy *);
        int     (* apr_flush)(struct aproxy *, int);
        void    *apr_soft;
} aproxy_t;

#define APR_DELETE      1

#define APR_ERR(x)      ((x) << 16)
#define APR_EXIT(x)     (((x) >> 16) & 0xffff)
#define APR_INC(x)      ((x) & 0xffff)


#ifdef _KERNEL
/*
 * Generic #define's to cover missing things in the kernel
 */
# ifndef isdigit
#  define isdigit(x)    ((x) >= '0' && (x) <= '9')
# endif
# ifndef isupper
#  define isupper(x)    (((unsigned)(x) >= 'A') && ((unsigned)(x) <= 'Z'))
# endif
# ifndef islower
#  define islower(x)    (((unsigned)(x) >= 'a') && ((unsigned)(x) <= 'z'))
# endif
# ifndef isalpha
#  define isalpha(x)    (isupper(x) || islower(x))
# endif
# ifndef toupper
#  define toupper(x)    (isupper(x) ? (x) : (x) - 'a' + 'A')
# endif
# ifndef isspace
#  define isspace(x)    (((x) == ' ') || ((x) == '\r') || ((x) == '\n') || \
                         ((x) == '\t') || ((x) == '\b'))
# endif
#endif /* _KERNEL */

/*
 * For the ftp proxy.
 */
#define FTP_BUFSZ       160
#define IPF_FTPBUFSZ    160

typedef struct  ftpside {
        char    *ftps_rptr;
        char    *ftps_wptr;
        void    *ftps_ifp;
        u_32_t  ftps_seq[2];
        u_32_t  ftps_len;
        int     ftps_junk;
        int     ftps_cmds;
        int     ftps_cmd;
        char    ftps_buf[FTP_BUFSZ];
} ftpside_t;

typedef struct  ftpinfo {
        int             ftp_passok;
        int             ftp_incok;
        void            *ftp_pendstate;
        nat_t           *ftp_pendnat;
        ftpside_t       ftp_side[2];
} ftpinfo_t;


/*
 * IPsec proxy
 */
typedef u_32_t          ipsec_cookie_t[2];

typedef struct ipsec_pxy {
        ipsec_cookie_t  ipsc_icookie;
        ipsec_cookie_t  ipsc_rcookie;
        int             ipsc_rckset;
        nat_t           *ipsc_nat;
        struct ipstate  *ipsc_state;
        ipnat_t         *ipsc_rule;
} ipsec_pxy_t;


/*
 * For the irc proxy.
 */
typedef struct  ircinfo {
        size_t  irc_len;
        char    *irc_snick;
        char    *irc_dnick;
        char    *irc_type;
        char    *irc_arg;
        char    *irc_addr;
        u_32_t  irc_ipnum;
        u_short irc_port;
} ircinfo_t;


/*
 * For the DNS "proxy"
 */
typedef struct dnsinfo {
        ipfmutex_t      dnsi_lock;
        u_short         dnsi_id;
        char            dnsi_buffer[512];
} dnsinfo_t;


/*
 * Real audio proxy structure and #defines
 */
typedef struct  raudio_s {
        int     rap_seenpna;
        int     rap_seenver;
        int     rap_version;
        int     rap_eos;        /* End Of Startup */
        int     rap_gotid;
        int     rap_gotlen;
        int     rap_mode;
        int     rap_sdone;
        u_short rap_plport;
        u_short rap_prport;
        u_short rap_srport;
        char    rap_svr[19];
        u_32_t  rap_sbf;        /* flag to indicate which of the 19 bytes have
                                 * been filled
                                 */
        u_32_t  rap_sseq;
} raudio_t;

#define RA_ID_END       0
#define RA_ID_UDP       1
#define RA_ID_ROBUST    7

#define RAP_M_UDP       1
#define RAP_M_ROBUST    2
#define RAP_M_TCP       4
#define RAP_M_UDP_ROBUST        (RAP_M_UDP|RAP_M_ROBUST)


/*
 * MSN RPC proxy
 */
typedef struct  msnrpcinfo      {
        u_int           mri_flags;
        int             mri_cmd[2];
        u_int           mri_valid;
        struct  in_addr mri_raddr;
        u_short         mri_rport;
} msnrpcinfo_t;


/*
 * Sun RPCBIND proxy
 */
#define RPCB_MAXMSG     888
#define RPCB_RES_PMAP   0       /* Response contains a v2 port. */
#define RPCB_RES_STRING 1       /* " " " v3 (GETADDR) string. */
#define RPCB_RES_LIST   2       /* " " " v4 (GETADDRLIST) list. */
#define RPCB_MAXREQS    32      /* Arbitrary limit on tracked transactions */

#define RPCB_REQMIN     40
#define RPCB_REQMAX     888
#define RPCB_REPMIN     20
#define RPCB_REPMAX     604     /* XXX double check this! */

/*
 * These macros determine the number of bytes between p and the end of
 * r->rs_buf relative to l.
 */
#define RPCB_BUF_END(r) (char *)((r)->rm_msgbuf + (r)->rm_buflen)
#define RPCB_BUF_GEQ(r, p, l)   \
        ((RPCB_BUF_END((r)) > (char *)(p)) &&           \
         ((RPCB_BUF_END((r)) - (char *)(p)) >= (l)))
#define RPCB_BUF_EQ(r, p, l)                            \
        (RPCB_BUF_END((r)) == ((char *)(p) + (l)))

/*
 * The following correspond to RPC(B) detailed in RFC183[13].
 */
#define RPCB_CALL               0
#define RPCB_REPLY              1
#define RPCB_MSG_VERSION        2
#define RPCB_PROG               100000
#define RPCB_GETPORT            3
#define RPCB_GETADDR            3
#define RPCB_GETADDRLIST        11
#define RPCB_MSG_ACCEPTED       0
#define RPCB_MSG_DENIED         1

/* BEGIN (Generic XDR structures) */
typedef struct xdr_string {
        u_32_t  *xs_len;
        char    *xs_str;
} xdr_string_t;

typedef struct xdr_auth {
        /* u_32_t       xa_flavor; */
        xdr_string_t    xa_string;
} xdr_auth_t;

typedef struct xdr_uaddr {
        u_32_t          xu_ip;
        u_short         xu_port;
        xdr_string_t    xu_str;
} xdr_uaddr_t;

typedef struct xdr_proto {
        u_int           xp_proto;
        xdr_string_t    xp_str;
} xdr_proto_t;

#define xu_xslen        xu_str.xs_len
#define xu_xsstr        xu_str.xs_str
#define xp_xslen        xp_str.xs_len
#define xp_xsstr        xp_str.xs_str
/* END (Generic XDR structures) */

/* BEGIN (RPC call structures) */
typedef struct pmap_args {
        /* u_32_t       pa_prog; */
        /* u_32_t       pa_vers; */
        u_32_t          *pa_prot;
        /* u_32_t       pa_port; */
} pmap_args_t;

typedef struct rpcb_args {
        /* u_32_t       *ra_prog; */
        /* u_32_t       *ra_vers; */
        xdr_proto_t     ra_netid;
        xdr_uaddr_t     ra_maddr;
        /* xdr_string_t ra_owner; */
} rpcb_args_t;

typedef struct rpc_call {
        /* u_32_t       rc_rpcvers; */
        /* u_32_t       rc_prog; */
        u_32_t  *rc_vers;
        u_32_t  *rc_proc;
        xdr_auth_t      rc_authcred;
        xdr_auth_t      rc_authverf;
        union {
                pmap_args_t     ra_pmapargs;
                rpcb_args_t     ra_rpcbargs;
        } rpcb_args;
} rpc_call_t;

#define rc_pmapargs     rpcb_args.ra_pmapargs
#define rc_rpcbargs     rpcb_args.ra_rpcbargs
/* END (RPC call structures) */

/* BEGIN (RPC reply structures) */
typedef struct rpcb_entry {
        xdr_uaddr_t     re_maddr;
        xdr_proto_t     re_netid;
        /* u_32_t       re_semantics; */
        xdr_string_t    re_family;
        xdr_proto_t     re_proto;
        u_32_t          *re_more; /* 1 == another entry follows */
} rpcb_entry_t;

typedef struct rpcb_listp {
        u_32_t          *rl_list; /* 1 == list follows */
        int             rl_cnt;
        rpcb_entry_t    rl_entries[2]; /* TCP / UDP only */
} rpcb_listp_t;

typedef struct rpc_resp {
        /* u_32_t       rr_acceptdeny; */
        /* Omitted 'message denied' fork; we don't care about rejects. */
        xdr_auth_t      rr_authverf;
        /* u_32_t               *rr_astat;      */
        union {
                u_32_t          *resp_pmap;
                xdr_uaddr_t     resp_getaddr;
                rpcb_listp_t    resp_getaddrlist;
        } rpcb_reply;
} rpc_resp_t;

#define rr_v2   rpcb_reply.resp_pmap
#define rr_v3   rpcb_reply.resp_getaddr
#define rr_v4   rpcb_reply.resp_getaddrlist
/* END (RPC reply structures) */

/* BEGIN (RPC message structure & macros) */
typedef struct rpc_msg {
        char    rm_msgbuf[RPCB_MAXMSG]; /* RPCB data buffer */
        u_int   rm_buflen;
        u_32_t  *rm_xid;
        /* u_32_t Call vs Reply */
        union {
                rpc_call_t      rb_call;
                rpc_resp_t      rb_resp;
        } rm_body;
} rpc_msg_t;

#define rm_call         rm_body.rb_call
#define rm_resp         rm_body.rb_resp
/* END (RPC message structure & macros) */

/*
 * These code paths aren't hot enough to warrant per transaction
 * mutexes.
 */
typedef struct rpcb_xact {
        struct  rpcb_xact       *rx_next;
        struct  rpcb_xact       **rx_pnext;
        u_32_t  rx_xid;         /* RPC transmission ID */
        u_int   rx_type;        /* RPCB response type */
        u_int   rx_ref;         /* reference count */
        u_int   rx_proto;       /* transport protocol (v2 only) */
} rpcb_xact_t;

typedef struct rpcb_session {
        ipfmutex_t      rs_rxlock;
        rpcb_xact_t     *rs_rxlist;
} rpcb_session_t;

/*
 * For an explanation, please see the following:
 *   RFC1832 - Sections 3.11, 4.4, and 4.5.
 */
#define XDRALIGN(x)     ((((x) % 4) != 0) ? ((((x) + 3) / 4) * 4) : (x))

extern  int     ipf_proxy_add(void *, aproxy_t *);
extern  int     ipf_proxy_check(fr_info_t *, struct nat *);
extern  int     ipf_proxy_ctl(ipf_main_softc_t *, void *, ap_ctl_t *);
extern  int     ipf_proxy_del(aproxy_t *);
extern  void    ipf_proxy_deref(aproxy_t *);
extern  void    ipf_proxy_flush(void *, int);
extern  int     ipf_proxy_init(void);
extern  int     ipf_proxy_ioctl(ipf_main_softc_t *, caddr_t, ioctlcmd_t, int, void *);
extern  aproxy_t        *ipf_proxy_lookup(void *, u_int, char *);
extern  int     ipf_proxy_match(fr_info_t *, struct nat *);
extern  int     ipf_proxy_new(fr_info_t *, struct nat *);
extern  int     ipf_proxy_ok(fr_info_t *, tcphdr_t *, struct ipnat *);
extern  void    ipf_proxy_free(ipf_main_softc_t *, ap_session_t *);
extern  int     ipf_proxy_main_load(void);
extern  int     ipf_proxy_main_unload(void);
extern  ipnat_t *ipf_proxy_rule_fwd(nat_t *);
extern  ipnat_t *ipf_proxy_rule_rev(nat_t *);
extern  void    *ipf_proxy_soft_create(ipf_main_softc_t *);
extern  void    ipf_proxy_soft_destroy(ipf_main_softc_t *, void *);
extern  int     ipf_proxy_soft_init(ipf_main_softc_t *, void *);
extern  int     ipf_proxy_soft_fini(ipf_main_softc_t *, void *);

#endif /* __IP_PROXY_H__ */