/* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
/* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */

/* Copyright (C) 2014 Stony Brook University
   This file is part of Graphene Library OS.

   Graphene Library OS 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, either version 3 of the
   License, or (at your option) any later version.

   Graphene Library OS 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 program.  If not, see <http://www.gnu.org/licenses/>.  */

/*
 * shim_handle.h
 *
 * Definitions of types and functions for file/handle bookkeeping.
 */

#ifndef _SHIM_HANDLE_H_
#define _SHIM_HANDLE_H_

#include <shim_types.h>
#include <shim_defs.h>
#include <shim_sysv.h>

#include <pal.h>
#include <list.h>

#include <linux/shm.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/un.h>

#include <asm/fcntl.h>

/* start definition of shim handle */
enum shim_handle_type {
    TYPE_FILE,
    TYPE_DEV,
    TYPE_PIPE,
    TYPE_SOCK,
    TYPE_DIR,
    TYPE_SHM,
    TYPE_SEM,
    TYPE_MSG,
    TYPE_FUTEX,
    TYPE_STR,
    TYPE_EPOLL,
};

struct shim_handle;
struct shim_thread;
struct shim_vma;

enum shim_file_type {
    FILE_UNKNOWN,
    FILE_REGULAR,
    FILE_DIR,
    FILE_DEV,
    FILE_TTY,
};

struct shim_file_data {
    LOCKTYPE            lock;
    struct atomic_int   version;
    bool                queried;
    enum shim_file_type type;
    mode_t     mode;
    struct atomic_int   size;
    struct shim_qstr    host_uri;
    unsigned long       atime;
    unsigned long       mtime;
    unsigned long       ctime;
    unsigned long       nlink;
};

struct shim_file_handle {
    unsigned int        version;
    struct shim_file_data * data;

    enum shim_file_type type;
    unsigned long       size;
    unsigned long       marker;

    enum { FILEBUF_MAP, FILEBUF_NONE } buf_type;
    unsigned long       mapsize;
    unsigned long       mapoffset;
    void *              mapbuf;
};

#define FILE_HANDLE_DATA(hdl)   ((hdl)->info.file.data)
#define FILE_DENTRY_DATA(dent)  ((struct shim_file_data *) (dent)->data)

struct shim_dev_ops {
    /* open: provide a filename relative to the mount point and flags,
       modify the shim handle */
    int (*open) (struct shim_handle * hdl, const char * name, int flags);

    /* close: clean up the file state inside the handle */
    int (*close) (struct shim_handle * hdl);

    /* read: the content from the file opened as handle */
    int (*read) (struct shim_handle * hdl, void * buf, size_t count);

    /* write: the content from the file opened as handle */
    int (*write) (struct shim_handle * hdl, const void * buf, size_t count);

    /* flush: flush out user buffer */
    int (*flush) (struct shim_handle * hdl);

    /* seek: the content from the file opened as handle */
    int (*seek) (struct shim_handle * hdl, off_t offset, int wence);

    int (*truncate) (struct shim_handle * hdl, uint64_t len);

    int (*mode) (const char * name, mode_t * mode);

    /* stat, hstat: get status of the file */
    int (*stat) (const char * name, struct stat * buf);
    int (*hstat) (struct shim_handle * hdl, struct stat * buf);
};

struct shim_dev_handle {
    struct shim_dev_ops     dev_ops;
};

struct shim_pipe_handle {
#if USE_SIMPLE_PIPE == 1
    struct shim_handle *    pair;
#else
    IDTYPE                  pipeid;
#endif
};

#define SOCK_STREAM     1
#define SOCK_DGRAM      2
#define SOCK_NONBLOCK   04000
#define SOCK_CLOEXEC    02000000

#define SOL_TCP         6

#define PF_LOCAL        1
#define PF_UNIX         PF_LOCAL
#define PF_FILE         PF_LOCAL
#define PF_INET         2
#define PF_INET6        10

#define AF_UNIX         PF_UNIX
#define AF_INET         PF_INET
#define AF_INET6        PF_INET6

enum shim_sock_state {
    SOCK_CREATED,
    SOCK_BOUND,
    SOCK_CONNECTED,
    SOCK_BOUNDCONNECTED,
    SOCK_LISTENED,
    SOCK_ACCEPTED,
    SOCK_SHUTDOWN,
};

struct shim_unix_data {
    unsigned int pipeid;
};

struct shim_sock_handle {
    int     domain;
    int     sock_type;
    int     protocol;
    int     error;

    enum shim_sock_state sock_state;

    union shim_sock_addr {
        // INET addr
        struct {
            struct addr_inet {
                unsigned short      port;
                unsigned short      ext_port;
                union {
                    struct in_addr  v4;
                    struct in6_addr v6;
                } addr;
            } bind, conn;
        } in;
        // UNIX addr
        struct addr_unix {
            struct shim_dentry * dentry;
            unsigned int         pipeid;
            struct shim_unix_data * data;
        } un;
    } addr;

    struct shim_sock_option {
        struct shim_sock_option * next;
        int     level;
        int     optname;
        int     optlen;
        char    optval[];
    } * pending_options;
};

struct shim_dirent {
    struct shim_dirent * next;
    unsigned long        ino;          /* Inode number */
    unsigned char        type;
    char                 name[];       /* File name (null-terminated) */
};

struct shim_dir_handle {
    int offset;
    struct shim_dentry * dotdot;
    struct shim_dentry * dot;
    struct shim_dentry ** buf;
    struct shim_dentry ** ptr;
};

struct shim_shm_handle {
    /* XXX: need to implement */
    void * __reserved;
};

struct msg_type;
struct msg_item;
struct msg_client;

#define MAX_SYSV_CLIENTS        32

DEFINE_LIST(shim_msg_handle);
struct shim_msg_handle {
    unsigned long       msqkey;         /* msg queue key from user */
    IDTYPE              msqid;          /* msg queue identifier */
    bool                owned;          /* owned by current process */
    struct shim_ipc_info * owner;
    LEASETYPE           lease;
    int                 perm;           /* access permissions */
    bool                deleted;        /* marking the queue deleted */
    int                 nmsgs;          /* number of msgs */
    int                 currentsize;    /* current size in bytes */
    struct msg_qobj *   queue;
    int                 queuesize;
    int                 queueused;
    struct msg_qobj *   freed;
    PAL_HANDLE          event;          /* event for waiting */
    int                 ntypes;
    int                 maxtypes;
    struct msg_type *   types;
    struct sysv_score   scores[MAX_SYSV_CLIENTS];
    LIST_TYPE(shim_msg_handle) list;
    LIST_TYPE(shim_msg_handle) key_hlist;
    LIST_TYPE(shim_msg_handle) qid_hlist;
};

struct sem_objs;

DEFINE_LIST(shim_sem_handle);
struct shim_sem_handle {
    unsigned long       semkey;
    IDTYPE              semid;
    bool                owned;
    struct shim_ipc_info * owner;
    LEASETYPE           lease;
    int                 perm;
    bool                deleted;
    PAL_HANDLE          event;
    int                 nsems;
    struct sem_obj *    sems;
    int                 nreqs;
    struct sysv_score   scores[MAX_SYSV_CLIENTS];
    LISTP_TYPE(sem_ops) migrated;
    LIST_TYPE(shim_sem_handle) list;
    LIST_TYPE(shim_sem_handle) key_hlist;
    LIST_TYPE(shim_sem_handle) sid_hlist;
};
DEFINE_LIST(futex_waiter);
DEFINE_LISTP(futex_waiter);
DEFINE_LIST(shim_futex_handle);
struct shim_futex_handle {
    unsigned int *      uaddr;
    LISTP_TYPE(futex_waiter) waiters;
    struct shim_vma *   vma;
    LIST_TYPE(shim_futex_handle) list;
};

struct shim_str_data {
    REFTYPE ref_count;
    char * str;
    size_t len;
    size_t buf_size;
    bool dirty;
    int (*update) (struct shim_handle * hdl);
    int (*modify) (struct shim_handle * hdl);
};

struct shim_str_handle {
    struct shim_str_data * data;       /* inode is stored in dentry, too.
                                          store pointer here for efficiency */
    char * ptr;
};

DEFINE_LIST(shim_epoll_fd);
DEFINE_LISTP(shim_epoll_fd);
struct shim_epoll_handle {
    int                 maxfds;
    int                 nfds;
    LISTP_TYPE(shim_epoll_fd) fds;
    FDTYPE *            pal_fds;
    PAL_HANDLE *        pal_handles;
    int                 npals;
    int                 nread;
    int                 nwaiters;
    AEVENTTYPE          event;
};

struct shim_mount;
struct shim_qstr;
struct shim_dentry;

/* The epolls list links to the back field of the shim_epoll_fd structure 
 */
struct shim_handle {
    enum shim_handle_type   type;

    REFTYPE             ref_count;

    char                    fs_type[8];
    struct shim_mount *     fs;
    struct shim_qstr        path;
    struct shim_dentry *    dentry;
    LISTP_TYPE(shim_epoll_fd) epolls;

    struct shim_qstr        uri;    /* URI representing this handle, it is not
                                     * necessary to be set. */

    PAL_HANDLE              pal_handle;

    union {
        struct shim_file_handle   file;
        struct shim_dev_handle    dev;
        struct shim_pipe_handle   pipe;
        struct shim_sock_handle   sock;
        struct shim_dir_handle    dir;
        struct shim_shm_handle    shm;
        struct shim_msg_handle    msg;
        struct shim_sem_handle    sem;
        struct shim_futex_handle  futex;
        struct shim_str_handle    str;
        struct shim_epoll_handle  epoll;
    } info;

    int                 flags;
    int                 acc_mode;
    IDTYPE              owner;
    REFTYPE             opened;
    LOCKTYPE            lock;
};

/* allocating / manage handle */
struct shim_handle * get_new_handle (void);
void flush_handle (struct shim_handle * hdl);
void open_handle (struct shim_handle * hdl);
void close_handle (struct shim_handle * hdl);
void get_handle (struct shim_handle * hdl);
void put_handle (struct shim_handle * hdl);

/* file descriptor table */
struct shim_fd_handle {
    FDTYPE      vfd;        /* virtual file descriptor */
    int         flags;      /* file descriptor flags, only FD_CLOEXEC */

    struct shim_handle * handle;
};

#define MAX_MAX_FDS         (65536)
#define DEFAULT_MAX_FDS     (1024)
extern unsigned int max_fds;

struct shim_handle_map {
    /* the top of created file descriptors */
    FDTYPE      fd_size;
    FDTYPE      fd_top;

    /* refrence count and lock */
    REFTYPE     ref_count;
    LOCKTYPE    lock;

    /* An array of file descriptor belong to this mapping */
    struct shim_fd_handle ** map;
};

/* allocating file descriptors */
#define FD_NULL ((FDTYPE) -1)
#define HANDLE_ALLOCATED(fd_handle) ((fd_handle) && (fd_handle)->vfd != FD_NULL)

struct shim_handle * __get_fd_handle (FDTYPE fd, int * flags,
                                      struct shim_handle_map * map);
struct shim_handle * get_fd_handle (FDTYPE fd, int * flags,
                                    struct shim_handle_map * map);
int set_new_fd_handle (struct shim_handle * hdl, int flags,
                       struct shim_handle_map * map);
int set_new_fd_handle_by_fd (FDTYPE fd, struct shim_handle * hdl,
                             int flags, struct shim_handle_map * map);
struct shim_handle *
__detach_fd_handle (struct shim_fd_handle * fd, int * flags,
                    struct shim_handle_map * map);
struct shim_handle * detach_fd_handle (FDTYPE fd, int * flags,
                                       struct shim_handle_map * map);

/* manage handle mapping */
int dup_handle_map (struct shim_handle_map ** new_map,
                    struct shim_handle_map * old_map);
int flush_handle_map (struct shim_handle_map * map);
void get_handle_map (struct shim_handle_map * map);
void put_handle_map (struct shim_handle_map * map);
int walk_handle_map (int (*callback) (struct shim_fd_handle *,
                                      struct shim_handle_map *, void *),
                     struct shim_handle_map * map, void * arg);

int init_handle (void);
int init_important_handles (void);

size_t get_file_size (struct shim_handle * file);

int do_handle_read (struct shim_handle * hdl, void * buf, int count);
int do_handle_write (struct shim_handle * hdl, const void * buf, int count);

#endif /* _SHIM_HANDLE_H_ */