include/types/fd.h

/*
  include/types/fd.h
  File descriptors states.

  Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation, version 2.1
  exclusively.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef _TYPES_FD_H
#define _TYPES_FD_H

#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

#include <common/config.h>
#include <types/task.h>
#include <types/buffers.h>
#include <types/protocols.h>

/* different possible states for the fd */
#define FD_STCLOSE	0
#define FD_STLISTEN	1
#define FD_STCONN	2
#define FD_STREADY	3
#define FD_STERROR	4

enum {
	DIR_RD=0,
	DIR_WR=1,
	DIR_SIZE
};

/*
 * FD_POLL_IN remains set as long as some data is pending for read.
 * FD_POLL_OUT remains set as long as the fd accepts to write data.
 * FD_POLL_ERR and FD_POLL_ERR remain set forever (until processed).
 */
#define FD_POLL_IN	0x01
#define FD_POLL_PRI	0x02
#define FD_POLL_OUT	0x04
#define FD_POLL_ERR	0x08
#define FD_POLL_HUP	0x10

#define FD_POLL_DATA    (FD_POLL_IN  | FD_POLL_OUT)
#define FD_POLL_STICKY  (FD_POLL_ERR | FD_POLL_HUP)

/* bit values for fdtab[fd]->flags. Most of them are used to hold a value
 * consecutive to a behaviour change.
 */
#define FD_FL_TCP               0x0001       /* socket is TCP */
#define FD_FL_TCP_NODELAY       0x0002
#define FD_FL_TCP_CORK          0x0004

/* info about one given fd */
struct fdtab {
	struct {
		int (*f)(int fd);            /* read/write function */
		struct buffer *b;            /* read/write buffer */
	} cb[DIR_SIZE];
	void *owner;                         /* the session (or proxy) associated with this fd */
	unsigned short flags;                /* various flags precising the exact status of this fd */
	unsigned char state;                 /* the state of this fd */
	unsigned char ev;                    /* event seen in return of poll() : FD_POLL_* */
	struct sockaddr *peeraddr;           /* pointer to peer's network address, or NULL if unset */
	socklen_t peerlen;                   /* peer's address length, or 0 if unset */
	int local_port;                      /* optional local port */
	struct port_range *port_range;       /* optional port range to bind to */
};

/*
 * Poller descriptors.
 *  - <name> is initialized by the poller's register() function, and should not
 *    be allocated, just linked to.
 *  - <pref> is initialized by the poller's register() function. It is set to 0
 *    by default, meaning the poller is disabled. init() should set it to 0 in
 *    case of failure. term() must set it to 0. A generic unoptimized select()
 *    poller should set it to 100.
 *  - <private> is initialized by the poller's init() function, and cleaned by
 *    the term() function.
 *  - cond_s() checks if fd was not set then sets it and returns 1. Otherwise
 *    it returns 0. It may be the same as set().
 *  - cond_c() checks if fd was set then clears it and returns 1. Otherwise
 *    it returns 0. It may be the same as clr().
 *  - clo() should be used to do indicate the poller that fd will be closed. It
 *    may be the same as rem() on some pollers.
 *  - poll() calls the poller, expiring at <exp>
 */
struct poller {
	void   *private;                                     /* any private data for the poller */
	int  REGPRM2 (*is_set)(const int fd, int dir);       /* check if <fd> is being polled for dir <dir> */
	int  REGPRM2    (*set)(const int fd, int dir);       /* set   polling on <fd> for <dir> */
	int  REGPRM2    (*clr)(const int fd, int dir);       /* clear polling on <fd> for <dir> */
	int  REGPRM2 (*cond_s)(const int fd, int dir);       /* set   polling on <fd> for <dir> if unset */
	int  REGPRM2 (*cond_c)(const int fd, int dir);       /* clear polling on <fd> for <dir> if set */
	void REGPRM1    (*rem)(const int fd);                /* remove any polling on <fd> */
	void REGPRM1    (*clo)(const int fd);                /* mark <fd> as closed */
    	void REGPRM2   (*poll)(struct poller *p, int exp);   /* the poller itself */
	int  REGPRM1   (*init)(struct poller *p);            /* poller initialization */
	void REGPRM1   (*term)(struct poller *p);            /* termination of this poller */
	int  REGPRM1   (*test)(struct poller *p);            /* pre-init check of the poller */
	int  REGPRM1   (*fork)(struct poller *p);            /* post-fork re-opening */
	const char   *name;                                  /* poller name */
	int    pref;                                         /* try pollers with higher preference first */
};

extern struct poller cur_poller; /* the current poller */
extern int nbpollers;
#define MAX_POLLERS	10
extern struct poller pollers[MAX_POLLERS];   /* all registered pollers */

extern struct fdtab *fdtab;             /* array of all the file descriptors */
extern int maxfd;                       /* # of the highest fd + 1 */
extern int totalconn;                   /* total # of terminated sessions */
extern int actconn;                     /* # of active sessions */

#endif /* _TYPES_FD_H */

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */