/*-
 * Copyright (c) 1982, 1986, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)socketvar.h 8.3 (Berkeley) 2/19/95
 * $FreeBSD: src/sys/sys/socketvar.h,v 1.46.2.10 2003/08/24 08:24:39 hsu Exp $
 * $DragonFly: src/sys/sys/socketvar.h,v 1.35 2008/08/28 23:15:45 dillon Exp $
 */

#ifndef _SYS_SOCKETVAR_H_
#define _SYS_SOCKETVAR_H_

#ifndef _SYS_TYPES_H_
#include <sys/types.h>
#endif
#ifndef _SYS_QUEUE_H_
#include <sys/queue.h>                  /* for TAILQ macros */
#endif
#ifndef _SYS_EVENT_H_
#include <sys/event.h>                  /* for struct kqinfo */
#endif
#ifndef _SYS_THREAD_H_
#include <sys/thread.h>                 /* for struct lwkt_token */
#endif
#ifndef _SYS_SOCKBUF_H_
#include <sys/sockbuf.h>
#endif

#if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)

#ifndef _NET_NETMSG_H_
#include <net/netmsg.h>
#endif

#ifndef _SYS_SPINLOCK_H_
#include <sys/spinlock.h>
#endif

struct accept_filter;

/*
 * Signaling socket buffers contain additional elements for locking
 * and signaling conditions.  These are used primarily by sockets.
 *
 * WARNING: See partial clearing of fields in kern/uipc_socket.c
 *          sorflush() and sowflush().
 */
struct signalsockbuf {
        struct sockbuf sb;
        struct kqinfo ssb_kq;   /* process selecting read/write */
        struct notifymsglist ssb_mlist; /* list of pending predicate messages */
        uint32_t ssb_flags;     /* flags, see below (use atomic ops) */
        u_int   ssb_timeo;      /* timeout for read/write */
        long    ssb_lowat;      /* low water mark */
        u_long  ssb_hiwat;      /* high water mark / max actual char count */
        u_long  ssb_mbmax;      /* max chars of mbufs to use */
        struct lwkt_token ssb_token; /* frontend/backend serializer */
};

#define ssb_cc          sb.sb_cc        /* commonly used fields */
#define ssb_mb          sb.sb_mb        /* commonly used fields */
#define ssb_mbcnt       sb.sb_mbcnt     /* commonly used fields */
#define ssb_cc_prealloc sb.sb_cc_prealloc
#define ssb_mbcnt_prealloc sb.sb_mbcnt_prealloc

#define SSB_LOCK        0x0001          /* lock on data queue */
#define SSB_WANT        0x0002          /* someone is waiting to lock */
#define SSB_WAIT        0x0004          /* someone is waiting for data/space */
#define SSB_ASYNC       0x0010          /* ASYNC I/O, need signals */
#define SSB_UPCALL      0x0020          /* someone wants an upcall */
#define SSB_NOINTR      0x0040          /* operations not interruptible */
/*#define SSB_AIO       0x0080*/        /* AIO operations queued */
#define SSB_KNOTE       0x0100          /* kernel note attached */
#define SSB_MEVENT      0x0200          /* need message event notification */
#define SSB_STOP        0x0400          /* backpressure indicator */
#define SSB_AUTOSIZE    0x0800          /* automatically size socket buffer */
#define SSB_AUTOLOWAT   0x1000          /* automatically scale lowat */
#define SSB_WAKEUP      0x2000          /* wakeup event race */
#define SSB_PREALLOC    0x4000          /* prealloc supported */
#define SSB_STOPSUPP    0x8000          /* SSB_STOP supported */

#define SSB_CLEAR_MASK  (SSB_ASYNC | SSB_UPCALL | SSB_STOP | \
                         SSB_AUTOSIZE | SSB_AUTOLOWAT)

#define SSB_NOTIFY_MASK (SSB_WAIT | SSB_ASYNC | SSB_UPCALL | \
                         SSB_KNOTE | SSB_MEVENT)

/*
 * Per-socket kernel structure.  Contains universal send and receive queues,
 * protocol control handle, and error information.
 */
struct socket {
        short   so_type;                /* generic type, see socket.h */
        short   so_options;             /* from socket call, see socket.h */
        short   so_linger;              /* time to linger while closing */
        short   so_state;               /* internal state flags SS_*, below */
        void    *so_pcb;                /* protocol control block */
        struct  protosw *so_proto;      /* protocol handle */
        struct  socket *so_head;        /* back pointer to accept socket */
        lwkt_port_t so_port;            /* message port */

        /*
         * These fields are used to manage sockets capable of accepting
         * new connections.
         */
        TAILQ_HEAD(, socket) so_incomp; /* in-progress, incomplete */
        TAILQ_HEAD(, socket) so_comp;   /* completed but not yet accepted */
        TAILQ_ENTRY(socket) so_list;    /* list of unaccepted connections */
        short   so_qlen;                /* so_comp count */
        short   so_incqlen;             /* so_incomp count */
        short   so_qlimit;              /* max number queued connections */

        /*
         * Misc socket support
         */
        short   so_timeo;               /* connection timeout */
        u_short so_error;               /* error affecting connection */
        u_short so_rerror;              /* error affecting receiving */
        struct  sigio *so_sigio;        /* information for async I/O or
                                           out of band data (SIGURG) */
        u_long  so_oobmark;             /* chars to oob mark */
        TAILQ_HEAD(, aiocblist) so_aiojobq; /* AIO ops waiting on socket */
        struct signalsockbuf so_rcv;
        struct signalsockbuf so_snd;

        void    (*so_upcall) (struct socket *, void *, int);
        void    *so_upcallarg;
        struct  ucred *so_cred;         /* user credentials */
        /* NB: generation count must not be first; easiest to make it last. */
        void    *so_emuldata;           /* private data for emulators */
        int     so_refs;                /* shutdown refs */
        int     so_reserved01;
        struct  so_accf {
                struct  accept_filter *so_accept_filter;
                void    *so_accept_filter_arg;  /* saved filter args */
                char    *so_accept_filter_str;  /* saved user args */
        } *so_accf;

        struct netmsg_base so_clomsg;
        struct sockaddr *so_faddr;

        struct spinlock so_rcvd_spin;
        struct netmsg_pru_rcvd so_rcvd_msg;

        lwkt_port_t so_orig_port;

        long    so_inum;

        uint32_t so_user_cookie;        /* user-specified metadata */
};

#endif

/*
 * Socket state bits.
 *
 * NOTE: The following states are interlocked with so_refs:
 *
 *      SS_NOFDREF      so_refs while not set
 *      (so_pcb)        so_refs while set
 */
#define SS_NOFDREF              0x0001  /* no file table ref any more */
#define SS_ISCONNECTED          0x0002  /* socket connected to a peer */
#define SS_ISCONNECTING         0x0004  /* in process of connecting to peer */
#define SS_ISDISCONNECTING      0x0008  /* in process of disconnecting */
#define SS_CANTSENDMORE         0x0010  /* can't send more data to peer */
#define SS_CANTRCVMORE          0x0020  /* can't receive more data from peer */
#define SS_RCVATMARK            0x0040  /* at mark on input */

#define SS_ISCLOSING            0x0080  /* in process of closing */
#define SS_ASSERTINPROG         0x0100  /* sonewconn race debugging */
#define SS_ASYNC                0x0200  /* async i/o notify */
#define SS_ISCONFIRMING         0x0400  /* deciding to accept connection req */

#define SS_INCOMP               0x0800  /* unaccepted, incomplete connection */
#define SS_COMP                 0x1000  /* unaccepted, complete connection */
#define SS_ISDISCONNECTED       0x2000  /* socket disconnected from peer */
#define SS_ACCEPTMECH           0x4000  /* allow bind override vs accepted */

/*
 * Externalized form of struct socket used by the sysctl(3) interface.
 */
struct  xsocket {
        size_t  xso_len;        /* length of this structure */
        struct  socket *xso_so; /* makes a convenient handle sometimes */
        short   so_type;
        short   so_options;
        short   so_linger;
        short   so_state;
        void    *so_pcb;                /* another convenient handle */
        int     xso_protocol;
        int     xso_family;
        short   so_qlen;
        short   so_incqlen;
        short   so_qlimit;
        short   so_timeo;
        u_short so_error;
        pid_t   so_pgid;
        u_long  so_oobmark;
        struct  xsockbuf {
                u_long  sb_cc;
                u_long  sb_hiwat;
                u_long  sb_mbcnt;
                u_long  sb_mbmax;
                long    sb_lowat;
                u_int   sb_timeo;
                short   sb_flags;
        } so_rcv, so_snd;
        uid_t   so_uid;         /* XXX */
};

/*
 * Macros for sockets and socket buffering.
 */

#define sosendallatonce(so) \
    ((so)->so_proto->pr_flags & PR_ATOMIC)

/* can we read something from so? */
#define soreadable(so) \
    ((so)->so_rcv.ssb_cc >= (so)->so_rcv.ssb_lowat || \
        ((so)->so_state & SS_CANTRCVMORE) || \
        !TAILQ_EMPTY(&(so)->so_comp) || (so)->so_error || (so)->so_rerror)

/* can we write something to so? */
#define sowriteable(so) \
    ((ssb_space(&(so)->so_snd) >= (so)->so_snd.ssb_lowat && \
        (((so)->so_state&SS_ISCONNECTED) || \
          ((so)->so_proto->pr_flags&PR_CONNREQUIRED)==0)) || \
     ((so)->so_state & SS_CANTSENDMORE) || \
     (so)->so_error)

/* do we have to send all at once on a socket? */

#ifdef _KERNEL

/*
 * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
 * This is problematical if the fields are unsigned, as the space might
 * still be negative (cc > hiwat or mbcnt > mbmax).  Should detect
 * overflow and return 0.
 *
 * SSB_STOP ignores cc/hiwat and returns 0.  This is used by unix domain
 * stream sockets to signal backpressure.
 */
static __inline
long
ssb_space(struct signalsockbuf *ssb)
{
        long bleft;
        long mleft;

        if (ssb->ssb_flags & SSB_STOP)
                return(0);
        bleft = ssb->ssb_hiwat - ssb->ssb_cc;
        mleft = ssb->ssb_mbmax - ssb->ssb_mbcnt;
        return((bleft < mleft) ? bleft : mleft);
}

static __inline long
ssb_space_prealloc(struct signalsockbuf *ssb)
{
        long bleft, bleft_prealloc;
        long mleft, mleft_prealloc;

        if (ssb->ssb_flags & SSB_STOP)
                return(0);

        bleft = ssb->ssb_hiwat - ssb->ssb_cc;
        bleft_prealloc = ssb->ssb_hiwat - ssb->ssb_cc_prealloc;
        if (bleft_prealloc < bleft)
                bleft = bleft_prealloc;

        mleft = ssb->ssb_mbmax - ssb->ssb_mbcnt;
        mleft_prealloc = ssb->ssb_mbmax - ssb->ssb_mbcnt_prealloc;
        if (mleft_prealloc < mleft)
                mleft = mleft_prealloc;

        return((bleft < mleft) ? bleft : mleft);
}

/*
 * NOTE: Only works w/ later ssb_appendstream() on m
 */
static __inline void
ssb_preallocstream(struct signalsockbuf *ssb, struct mbuf *m)
{
        if (m->m_len == 0)
                return;
        sbprealloc(&ssb->sb, m);
}

#endif

#define ssb_append(ssb, m)                                              \
        sbappend(&(ssb)->sb, m)

#define ssb_appendstream(ssb, m)                                        \
        sbappendstream(&(ssb)->sb, m)

#define ssb_appendrecord(ssb, m)                                        \
        sbappendrecord(&(ssb)->sb, m)

#define ssb_appendaddr(ssb, src, m, control)                            \
        ((ssb_space(ssb) <= 0) ? 0 : sbappendaddr(&(ssb)->sb, src, m, control))

#define ssb_appendcontrol(ssb, m, control)                              \
        ((ssb_space(ssb) <= 0) ? 0 : sbappendcontrol(&(ssb)->sb, m, control))

#define ssb_insert_knote(ssb, kn) do {                                  \
        knote_insert(&(ssb)->ssb_kq.ki_note, kn);                       \
        atomic_set_int(&(ssb)->ssb_flags, SSB_KNOTE);                   \
} while(0)

#define ssb_remove_knote(ssb, kn) do {                                  \
        knote_remove(&(ssb)->ssb_kq.ki_note, kn);                       \
        if (SLIST_EMPTY(&(ssb)->ssb_kq.ki_note))                        \
                atomic_clear_int(&(ssb)->ssb_flags, SSB_KNOTE);         \
} while(0)

#define sorwakeup(so)   sowakeup((so), &(so)->so_rcv)
#define sowwakeup(so)   sowakeup((so), &(so)->so_snd)

#ifdef _KERNEL

/*
 * Argument structure for sosetopt et seq.  This is in the KERNEL
 * section because it will never be visible to user code.
 */
enum sopt_dir { SOPT_GET, SOPT_SET };
struct sockopt {
        enum    sopt_dir sopt_dir; /* is this a get or a set? */
        int     sopt_level;     /* second arg of [gs]etsockopt */
        int     sopt_name;      /* third arg of [gs]etsockopt */
        void   *sopt_val;       /* fourth arg of [gs]etsockopt */
        size_t  sopt_valsize;   /* (almost) fifth arg of [gs]etsockopt */
        struct  thread *sopt_td; /* calling thread or null if kernel */
};

struct accept_filter {
        char    accf_name[16];
        void    (*accf_callback)
                (struct socket *so, void *arg, int waitflag);
        void *  (*accf_create)
                (struct socket *so, char *arg);
        void    (*accf_destroy)
                (struct socket *so);
        SLIST_ENTRY(accept_filter) accf_next;   /* next on the list */
};

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_PCB);
MALLOC_DECLARE(M_SONAME);
MALLOC_DECLARE(M_ACCF);
#endif

extern int      maxsockets;
extern u_long   sb_max;         /* nominal limit */
extern u_long   sb_max_adj;     /* actual limit used by sbreserve() */

struct file;
struct filedesc;
struct mbuf;
struct rlimit;
struct sockaddr;
struct stat;
struct ucred;
struct uio;
struct knote;
struct sysmsg;

/*
 * File operations on sockets.
 */
int     soo_read (struct file *fp, struct uio *uio, struct ucred *cred,
                        int flags);
int     soo_write (struct file *fp, struct uio *uio, struct ucred *cred,
                        int flags);
int     soo_close (struct file *fp);
int     soo_shutdown (struct file *fp, int how);
int     soo_ioctl (struct file *fp, u_long cmd, caddr_t data,
                        struct ucred *cred, struct sysmsg *msg);
int     soo_stat (struct file *fp, struct stat *ub, struct ucred *cred);
int     sokqfilter (struct file *fp, struct knote *kn);

/*
 * From uipc_socket and friends
 */
struct  sockaddr *dup_sockaddr (const struct sockaddr *sa);
int     getsockaddr (struct sockaddr **namp, caddr_t uaddr, size_t len);

void    ssb_release (struct signalsockbuf *ssb, struct socket *so);
int     ssb_reserve (struct signalsockbuf *ssb, u_long cc, struct socket *so,
                   struct rlimit *rl);
void    ssbtoxsockbuf (struct signalsockbuf *sb, struct xsockbuf *xsb);
int     ssb_wait (struct signalsockbuf *sb);
int     _ssb_lock (struct signalsockbuf *sb);

void    soabort_async (struct socket *so, boolean_t clr_head);
void    soabort_direct (struct socket *so);
int     soaccept (struct socket *so, struct sockaddr **nam);
void    soaccept_generic (struct socket *so);
struct  socket *soalloc (int waitok, struct protosw *);
int     sobind (struct socket *so, struct sockaddr *nam, struct thread *td);
void    socantrcvmore (struct socket *so);
void    socantsendmore (struct socket *so);
void    soroverflow(struct socket *so);
int     socket_wait (struct socket *so, struct timespec *ts, int *res);
int     soclose (struct socket *so, int fflags);
int     soconnect (struct socket *so, struct sockaddr *nam, struct thread *td,
            boolean_t sync);
int     soconnect2 (struct socket *so1, struct socket *so2, struct ucred *cred);
int     socreate (int dom, struct socket **aso, int type, int proto,
            struct thread *td);
int     sodisconnect (struct socket *so);
void    sodiscard (struct socket *so);
void    sofree (struct socket *so);
int     sogetopt (struct socket *so, struct sockopt *sopt);
void    sohasoutofband (struct socket *so);
void    soisconnected (struct socket *so);
void    soisconnecting (struct socket *so);
void    soisdisconnected (struct socket *so);
void    soisdisconnecting (struct socket *so);
void    soisreconnected (struct socket *so);
void    soisreconnecting (struct socket *so);
void    sosetport (struct socket *so, struct lwkt_port *port);
int     solisten (struct socket *so, int backlog, struct thread *td);
struct socket *sonewconn (struct socket *head, int connstatus);
struct socket *sonewconn_faddr (struct socket *head, int connstatus,
            const struct sockaddr *faddr, boolean_t keep_ref);
void    soinherit(struct socket *so, struct socket *so_inh);
int     sooptcopyin (struct sockopt *sopt, void *buf, size_t len,
                         size_t minlen);
int     soopt_to_kbuf (struct sockopt *sopt, void *buf, size_t len,
                         size_t minlen);
int     sooptcopyout (struct sockopt *sopt, const void *buf, size_t len);
void    soopt_from_kbuf (struct sockopt *sopt, const void *buf, size_t len);

/* XXX; prepare mbuf for (__FreeBSD__ < 3) routines. */
int     soopt_getm (struct sockopt *sopt, struct mbuf **mp);
int     soopt_mcopyin (struct sockopt *sopt, struct mbuf *m);
void    soopt_to_mbuf (struct sockopt *sopt, struct mbuf *m);
int     soopt_mcopyout (struct sockopt *sopt, struct mbuf *m);
int     soopt_from_mbuf (struct sockopt *sopt, struct mbuf *m);

int     soreceive (struct socket *so, struct sockaddr **paddr,
                       struct uio *uio, struct sockbuf *sio,
                       struct mbuf **controlp, int *flagsp);
int     sorecvtcp (struct socket *so, struct sockaddr **paddr,
                       struct uio *uio, struct sockbuf *sio,
                       struct mbuf **controlp, int *flagsp);
int     soreserve (struct socket *so, u_long sndcc, u_long rcvcc,
                   struct rlimit *rl);
void    sorflush (struct socket *so);
int     sosend (struct socket *so, struct sockaddr *addr, struct uio *uio,
                    struct mbuf *top, struct mbuf *control, int flags,
                    struct thread *td);
int     sosendudp (struct socket *so, struct sockaddr *addr, struct uio *uio,
                    struct mbuf *top, struct mbuf *control, int flags,
                    struct thread *td);
int     sosendtcp (struct socket *so, struct sockaddr *addr, struct uio *uio,
                    struct mbuf *top, struct mbuf *control, int flags,
                    struct thread *td);
int     sosetopt (struct socket *so, struct sockopt *sopt);
int     soshutdown (struct socket *so, int how);
void    sotoxsocket (struct socket *so, struct xsocket *xso);
void    sowakeup (struct socket *so, struct signalsockbuf *sb);

/* accept filter functions */
int     accept_filt_add (struct accept_filter *filt);
int     accept_filt_del (char *name);
struct accept_filter *  accept_filt_get (char *name);
#ifdef ACCEPT_FILTER_MOD
int accept_filt_generic_mod_event (module_t mod, int event, void *data);
SYSCTL_DECL(_net_inet_accf);
#endif /* ACCEPT_FILTER_MOD */

#endif /* _KERNEL */

#endif /* !_SYS_SOCKETVAR_H_ */