/* -*- 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_utils.h
 */

#ifndef _SHIM_UTILS_H_
#define _SHIM_UTILS_H_

#include <shim_handle.h>

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

struct shim_handle;

void sysparser_printf (const char * fmt, ...);

/* string object */
struct shim_str * get_str_obj (void);
int free_str_obj (struct shim_str * str);
int init_str_mgr (void);

/* qstring object */
#define QSTR_INIT  { .len = 0, .oflow = NULL }

static inline const char * qstrgetstr (const struct shim_qstr * qstr)
{
    return qstr->oflow ? qstr->oflow->str : qstr->name;
}

static inline void qstrfree (struct shim_qstr * qstr)
{
    if (qstr->oflow) {
        free_str_obj(qstr->oflow);
        qstr->oflow = NULL;
    }

    qstr->name[0] = 0;
    qstr->len = 0;
}

static inline char * qstrsetstr (struct shim_qstr * qstr,
                                 const char * str, size_t size)
{
    if (!str) {
        qstrfree(qstr);
        return NULL;
    }

    if (size >= STR_SIZE)
        return NULL;

    char * buf = qstr->name;

    if (size >= QSTR_SIZE) {
        if (!qstr->oflow) {
            qstr->oflow = get_str_obj();
            if (!qstr->oflow)
                return NULL;
        }
        buf = qstr->oflow->str;
    } else {
        if (qstr->oflow) {
            free_str_obj(qstr->oflow);
            qstr->oflow = NULL;
        }
    }

    memcpy(buf, str, size);
    buf[size] = 0;
    qstr->len = size;

    return buf;
}

static inline char * qstrsetstrs (struct shim_qstr * qstr,
                                  int nstrs,
                                  const char ** strs, size_t * sizes)
{
    size_t total_size = 0;

    for (int i = 0 ; i < nstrs ; i++)
        total_size += sizes[i];

    if (total_size >= STR_SIZE)
        return NULL;

    char * buf = qstr->name;

    if (total_size >= QSTR_SIZE) {
        if (!qstr->oflow) {
            // TODO: alloc proper size.
            qstr->oflow = get_str_obj();
            if (!qstr->oflow)
                return NULL;
        }
        buf = qstr->oflow->str;
    }

    char * ptr = buf;
    qstr->len = 0;

    for (int i = 0 ; i < nstrs ; i++) {
        int size = sizes[i];
        memcpy(ptr, strs[i], size);
        ptr[size] = 0;
        qstr->len += size;
        ptr += size;
    }

    return buf;
}

static inline int qstrempty (const struct shim_qstr * qstr)
{
    return qstr->len == 0;
}

static inline void qstrcopy (struct shim_qstr * to,
                             const struct shim_qstr * from)
{
    qstrsetstr(to, qstrgetstr(from), from->len);
    to->hash = from->hash;
}

static inline int qstrcmpstr (const struct shim_qstr * qstr,
                              const char * str, size_t size)
{
    if (qstr->len != size)
        return 1;

    return memcmp(qstrgetstr(qstr), str, size);
}

//#define SLAB_DEBUG_PRINT
//#define SLAB_DEBUG_TRACE

/* heap allocation functions */
int init_slab (void);

#if defined(SLAB_DEBUG_PRINT) || defined(SLAB_DEBUG_TRACE)
void * __malloc_debug (size_t size, const char * file, int line);
#define malloc(size) __malloc_debug((size), __FILE__, __LINE__)
void __free_debug (void * mem, const char * file, int line);
#define free(mem) __free_debug((mem), __FILE__, __LINE__)
void * __malloc_copy_debug (const void * mem, size_t size,
                             const char * file, int line);
#define malloc_copy(mem, size) __malloc_copy_debug((mem), (size), __FILE__, __LINE__)
#else
void * malloc (size_t size);
void free (void * mem);
void * malloc_copy (const void * mem, size_t size);
#endif

static_always_inline
char * qstrtostr (struct shim_qstr * qstr, bool on_stack)
{
    int len = qstr->len;
    char * buf = on_stack ? __alloca(len + 1) : malloc(len + 1);

    if (!buf)
        return NULL;

    memcpy(buf, qstrgetstr(qstr), len);

    buf[len] = 0;
    return buf;
}


/* typedef a 32 bit type */
# ifndef UINT4
# define UINT4 uint32_t
# endif

/* Data structure for MD5 (Message Digest) computation */
struct shim_md5_ctx {
    UINT4 i[2];                   /* number of _bits_ handled mod 2^64 */
    UINT4 buf[4];                                    /* scratch buffer */
    unsigned char in[64];                              /* input buffer */
    unsigned char digest[16];     /* actual digest after MD5Final call */
};

void md5_init (struct shim_md5_ctx * mdContext);
void md5_update (struct shim_md5_ctx * mdContext, const void * buf,
                       size_t len);
void md5_final (struct shim_md5_ctx * mdContext);

/* prompt user for confirmation */
int message_confirm (const char * message, const char * options);

/* get random bytes (not for crypto!) */
void getrand (void * buffer, size_t size);

/* ELF binary loading */
int check_elf_object (struct shim_handle * file);
int load_elf_object (struct shim_handle * file, void * addr, size_t mapped);
int load_elf_interp (struct shim_handle * exec);
int free_elf_interp (void);
int execute_elf_object (struct shim_handle * exec, int argc, const char ** argp,
                        int nauxv, elf_auxv_t * auxp);
int remove_loaded_libraries (void);

/* gdb debugging support */
void remove_r_debug (void * addr);
void append_r_debug (const char * uri, void * addr, void * dyn_addr);
void clean_link_map_list (void);

/* create unique files/pipes */
#define PIPE_URI_SIZE   40
int create_pipe (IDTYPE * pipeid, char * uri, size_t size, PAL_HANDLE * hdl,
                 struct shim_qstr * qstr);
int create_dir (const char * prefix, char * path, size_t size,
                struct shim_handle ** hdl);
int create_file (const char * prefix, char * path, size_t size,
                 struct shim_handle ** hdl);
int create_handle (const char * prefix, char * path, size_t size,
                   PAL_HANDLE * hdl, unsigned int * id);


/* Asynchronous event support */
int init_async (void);
int64_t install_async_event (PAL_HANDLE object, unsigned long time,
                              void (*callback) (IDTYPE caller, void * arg),
                              void * arg);
int create_async_helper (void);
struct shim_thread * terminate_async_helper (void);

extern struct config_store * root_config;

#endif /* _SHIM_UTILS_H */