mariadb/sql/sql_acl.cc

/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


/*
  The privileges are saved in the following tables:
  mysql/user	 ; super user who are allowed to do almoust anything
  mysql/host	 ; host priviliges. This is used if host is empty in mysql/db.
  mysql/db	 ; database privileges / user

  data in tables is sorted according to how many not-wild-cards there is
  in the relevant fields. Empty strings comes last.
*/

#include "mysql_priv.h"
#include "sql_acl.h"
#include "hash_filo.h"
#include <m_ctype.h>
#include <stdarg.h>

/*
 ACL_HOST is used if no host is specified
 */

struct acl_host_and_ip
{
  char *hostname;
  long ip,ip_mask;			// Used with masked ip:s
};

class ACL_ACCESS {
public:
  ulong sort;
  uint access;
};

class ACL_HOST :public ACL_ACCESS
{
public:
  acl_host_and_ip host;
  char *db;
};

class ACL_USER :public ACL_ACCESS
{
public:
  acl_host_and_ip host;
  uint hostname_length;
  char *user,*password;
  ulong salt[2];
};

class ACL_DB :public ACL_ACCESS
{
public:
  acl_host_and_ip host;
  char *user,*db;
};

class acl_entry :public hash_filo_element
{
public:
  uint access;
  uint16 length;
  char key[1];					// Key will be stored here
};

static byte* acl_entry_get_key(acl_entry *entry,uint *length,
			       my_bool not_used __attribute__((unused)))
{
  *length=(uint) entry->length;
  return (byte*) entry->key;
}

#define ACL_KEY_LENGTH (sizeof(long)+NAME_LEN+17)

static DYNAMIC_ARRAY acl_hosts,acl_users,acl_dbs;
static MEM_ROOT mem, memex;
static bool initialized=0;
static bool allow_all_hosts=1;
static HASH acl_check_hosts, hash_tables;
static DYNAMIC_ARRAY acl_wild_hosts;
static hash_filo *acl_cache;
static uint grant_version=0;
static uint get_access(TABLE *form,uint fieldnr);
static int acl_compare(ACL_ACCESS *a,ACL_ACCESS *b);
static ulong get_sort(uint count,...);
static void init_check_host(void);
static ACL_USER *find_acl_user(const char *host, const char *user);
static bool update_user_table(THD *thd, const char *host, const char *user,
			      const char *new_password);
static void update_hostname(acl_host_and_ip *host, const char *hostname);
static bool compare_hostname(const acl_host_and_ip *host, const char *hostname,
			     const char *ip);

int  acl_init(bool dont_read_acl_tables)
{
  THD  *thd;
  TABLE_LIST tables[3];
  TABLE *table;
  READ_RECORD read_record_info;
  DBUG_ENTER("acl_init");

  if (!acl_cache)
    acl_cache=new hash_filo(ACL_CACHE_SIZE,0,0,
			    (hash_get_key) acl_entry_get_key,
			    (void (*)(void*)) free);
  if (dont_read_acl_tables)
    DBUG_RETURN(0); /* purecov: tested */

  if (!(thd=new THD))
    DBUG_RETURN(1); /* purecov: inspected */
  acl_cache->clear(1);				// Clear locked hostname cache
  thd->version=refresh_version;
  thd->mysys_var=my_thread_var;
  thd->current_tablenr=0;
  thd->open_tables=0;
  thd->db=my_strdup("mysql",MYF(0));
  bzero((char*) &tables,sizeof(tables));
  tables[0].name=tables[0].real_name=(char*) "host";
  tables[1].name=tables[1].real_name=(char*) "user";
  tables[2].name=tables[2].real_name=(char*) "db";
  tables[0].next=tables+1;
  tables[1].next=tables+2;
  tables[0].lock_type=tables[1].lock_type=tables[2].lock_type=TL_READ;
  tables[0].db=tables[1].db=tables[2].db=thd->db;

  if (open_tables(thd,tables))
  {
    close_thread_tables(thd); /* purecov: inspected */
    delete thd; /* purecov: inspected */
    DBUG_RETURN(1); /* purecov: inspected */
  }
  TABLE *ptr[3];				// Lock tables for quick update
  ptr[0]= tables[0].table;
  ptr[1]= tables[1].table;
  ptr[2]= tables[2].table;
  MYSQL_LOCK *lock=mysql_lock_tables(thd,ptr,3);
  if (!lock)
  {
    close_thread_tables(thd); /* purecov: inspected */
    delete thd; /* purecov: inspected */
    DBUG_RETURN(1); /* purecov: inspected */
  }

  init_sql_alloc(&mem,1024,0);
  init_read_record(&read_record_info,thd,table= tables[0].table,NULL,1,0);
  VOID(init_dynamic_array(&acl_hosts,sizeof(ACL_HOST),20,50));
  while (!(read_record_info.read_record(&read_record_info)))
  {
    ACL_HOST host;
    update_hostname(&host.host,get_field(&mem, table,0));
    host.db=get_field(&mem, table,1);
    host.access=get_access(table,2);
    host.access=fix_rights_for_db(host.access);
    host.sort=get_sort(2,host.host.hostname,host.db);
#ifndef TO_BE_REMOVED
    if (table->fields ==  8)
    {						// Without grant
      if (host.access & CREATE_ACL)
	host.access|=REFERENCES_ACL | INDEX_ACL | ALTER_ACL;
    }
#endif
    VOID(push_dynamic(&acl_hosts,(gptr) &host));
  }
  qsort((gptr) dynamic_element(&acl_hosts,0,ACL_HOST*),acl_hosts.elements,
	sizeof(ACL_HOST),(qsort_cmp) acl_compare);
  end_read_record(&read_record_info);
  freeze_size(&acl_hosts);

  init_read_record(&read_record_info,thd,table=tables[1].table,NULL,1,0);
  VOID(init_dynamic_array(&acl_users,sizeof(ACL_USER),50,100));
  if (table->field[2]->field_length == 8 &&
      protocol_version == PROTOCOL_VERSION)
  {
    sql_print_error(
	    "Old 'user' table. (Check README or the Reference manual). Continuing --old-protocol"); /* purecov: tested */
    protocol_version=9; /* purecov: tested */
  }

  allow_all_hosts=0;
  while (!(read_record_info.read_record(&read_record_info)))
  {
    ACL_USER user;
    uint length=0;
    update_hostname(&user.host,get_field(&mem, table,0));
    user.user=get_field(&mem, table,1);
    user.password=get_field(&mem, table,2);
    if (user.password && (length=(uint) strlen(user.password)) == 8 &&
	protocol_version == PROTOCOL_VERSION)
    {
      sql_print_error(
		      "Found old style password for user '%s'. Ignoring user. (You may want to restart using --old-protocol)",
		      user.user ? user.user : ""); /* purecov: tested */
    }
    else if (length % 8)		// This holds true for passwords
    {
      sql_print_error(
		      "Found invalid password for user: '%s@%s'; Ignoring user",
		      user.user ? user.user : "",
		      user.host.hostname ? user.host.hostname : ""); /* purecov: tested */
      continue; /* purecov: tested */
    }
    get_salt_from_password(user.salt,user.password);
    user.access=get_access(table,3);
    user.sort=get_sort(2,user.host.hostname,user.user);
    user.hostname_length=user.host.hostname ? (uint) strlen(user.host.hostname) : 0;
#ifndef TO_BE_REMOVED
    if (table->fields <= 13)
    {						// Without grant
      if (user.access & CREATE_ACL)
	user.access|=REFERENCES_ACL | INDEX_ACL | ALTER_ACL;
    }
#endif
    VOID(push_dynamic(&acl_users,(gptr) &user));
    if (!user.host.hostname || user.host.hostname[0] == wild_many &&
	!user.host.hostname[1])
      allow_all_hosts=1;			// Anyone can connect
  }
  qsort((gptr) dynamic_element(&acl_users,0,ACL_USER*),acl_users.elements,
	sizeof(ACL_USER),(qsort_cmp) acl_compare);
  end_read_record(&read_record_info);
  freeze_size(&acl_users);

  init_read_record(&read_record_info,thd,table=tables[2].table,NULL,1,0);
  VOID(init_dynamic_array(&acl_dbs,sizeof(ACL_DB),50,100));
  while (!(read_record_info.read_record(&read_record_info)))
  {
    ACL_DB db;
    update_hostname(&db.host,get_field(&mem, table,0));
    db.db=get_field(&mem, table,1);
    db.user=get_field(&mem, table,2);
    db.access=get_access(table,3);
    db.access=fix_rights_for_db(db.access);
    db.sort=get_sort(3,db.host.hostname,db.db,db.user);
#ifndef TO_BE_REMOVED
    if (table->fields <=  9)
    {						// Without grant
      if (db.access & CREATE_ACL)
	db.access|=REFERENCES_ACL | INDEX_ACL | ALTER_ACL;
    }
#endif
    VOID(push_dynamic(&acl_dbs,(gptr) &db));
  }
  qsort((gptr) dynamic_element(&acl_dbs,0,ACL_DB*),acl_dbs.elements,
	sizeof(ACL_DB),(qsort_cmp) acl_compare);
  end_read_record(&read_record_info);
  freeze_size(&acl_dbs);
  init_check_host();

  mysql_unlock_tables(thd, lock);
  thd->version--;				// Force close to free memory
  close_thread_tables(thd);
  delete thd;
  initialized=1;
  DBUG_RETURN(0);
}


void acl_free(bool end)
{
  free_root(&mem,MYF(0));
  delete_dynamic(&acl_hosts);
  delete_dynamic(&acl_users);
  delete_dynamic(&acl_dbs);
  delete_dynamic(&acl_wild_hosts);
  hash_free(&acl_check_hosts);
  if (!end)
    acl_cache->clear(1); /* purecov: inspected */
  else
  {
    delete acl_cache;
    acl_cache=0;
  }
}

	/* Reload acl list if possible */

void acl_reload(void)
{
  DYNAMIC_ARRAY old_acl_hosts,old_acl_users,old_acl_dbs;
  MEM_ROOT old_mem;
  bool old_initialized;
  DBUG_ENTER("acl_reload");

  if (current_thd && current_thd->locked_tables)
  {					// Can't have locked tables here
    current_thd->lock=current_thd->locked_tables;
    current_thd->locked_tables=0;
    close_thread_tables(current_thd);
  }
  if ((old_initialized=initialized))
    VOID(pthread_mutex_lock(&acl_cache->lock));

  old_acl_hosts=acl_hosts;
  old_acl_users=acl_users;
  old_acl_dbs=acl_dbs;
  old_mem=mem;
  delete_dynamic(&acl_wild_hosts);
  hash_free(&acl_check_hosts);

  if (acl_init(0))
  {					// Error. Revert to old list
    acl_free();					/* purecov: inspected */
    acl_hosts=old_acl_hosts;
    acl_users=old_acl_users;
    acl_dbs=old_acl_dbs;
    mem=old_mem;
    init_check_host();
  }
  else
  {
    free_root(&old_mem,MYF(0));
    delete_dynamic(&old_acl_hosts);
    delete_dynamic(&old_acl_users);
    delete_dynamic(&old_acl_dbs);
  }
  if (old_initialized)
    VOID(pthread_mutex_unlock(&acl_cache->lock));
  DBUG_VOID_RETURN;
}


/* Get all access bits from table after fieldnr */

static uint get_access(TABLE *form,uint fieldnr)
{
  uint access_bits=0,bit;
  char buff[2];
  String res(buff,sizeof(buff));
  Field **pos;

  for (pos=form->field+fieldnr,bit=1 ; *pos ; pos++ , bit<<=1)
  {
    (*pos)->val_str(&res,&res);
    if (toupper(res[0]) == 'Y')
      access_bits|=bit;
  }
  return access_bits;
}


/*
 return a number with if sorted put string in this order:
 no wildcards
 wildcards
 empty string
 */

static ulong get_sort(uint count,...)
{
  va_list args;
  va_start(args,count);
  ulong sort=0;

  while (count--)
  {
    char *str=va_arg(args,char*);
    uint chars=0,wild=0;

    if (str)
    {
      for (; *str ; str++)
      {
	if (*str == wild_many || *str == wild_one || *str == wild_prefix)
	  wild++;
	else
	  chars++;
      }
    }
    sort= (sort << 8) + (wild ? 1 : chars ? 2 : 0);
  }
  va_end(args);
  return sort;
}


static int acl_compare(ACL_ACCESS *a,ACL_ACCESS *b)
{
  if (a->sort > b->sort)
    return -1;
  if (a->sort < b->sort)
    return 1;
  return 0;
}


/* Get master privilges for user (priviliges for all tables) */


uint acl_getroot(const char *host, const char *ip, const char *user,
		 const char *password,const char *message,char **priv_user,
		 bool old_ver)
{
  uint user_access=NO_ACCESS;
  *priv_user=(char*) user;

  if (!initialized)
    return (uint) ~NO_ACCESS;			// If no data allow anything /* purecov: tested */
  VOID(pthread_mutex_lock(&acl_cache->lock));

  /*
    Get possible access from user_list. This is or'ed to others not
    fully specified
  */
  for (uint i=0 ; i < acl_users.elements ; i++)
  {
    ACL_USER *acl_user=dynamic_element(&acl_users,i,ACL_USER*);
    if (!acl_user->user || !strcmp(user,acl_user->user))
    {
      if (compare_hostname(&acl_user->host,host,ip))
      {
	if (!acl_user->password && !*password ||
	    (acl_user->password && *password &&
	     !check_scramble(password,message,acl_user->salt,
			     (my_bool) old_ver)))
	{
	  user_access=acl_user->access;
	  if (!acl_user->user)
	    *priv_user=(char*) "";	// Change to anonymous user /* purecov: inspected */
	  break;
	}
#ifndef ALLOW_DOWNGRADE_OF_USERS
	break;				// Wrong password breaks loop /* purecov: inspected */
#endif
      }
    }
  }
  VOID(pthread_mutex_unlock(&acl_cache->lock));
  return user_access;
}


/*
** Functions to add and change user and database privileges when one
** changes things with GRANT
*/

static byte* check_get_key(ACL_USER *buff,uint *length,
			   my_bool not_used __attribute__((unused)))
{
  *length=buff->hostname_length;
  return (byte*) buff->host.hostname;
}

static void acl_update_user(const char *user, const char *host,
			    const char *password, uint privileges)
{
  for (uint i=0 ; i < acl_users.elements ; i++)
  {
    ACL_USER *acl_user=dynamic_element(&acl_users,i,ACL_USER*);
    if (!acl_user->user && !user[0] ||
	acl_user->user &&
	!strcmp(user,acl_user->user))
    {
      if (!acl_user->host.hostname && !host[0] ||
	  acl_user->host.hostname && !strcmp(host,acl_user->host.hostname))
      {
	acl_user->access=privileges;
	if (password)
	{
	  if (!password[0])
	    acl_user->password=0;
	  else
	  {
	    acl_user->password=(char*) "";	// Just point at something
	    get_salt_from_password(acl_user->salt,password);
	  }
	}
	break;
      }
    }
  }
}


static void acl_insert_user(const char *user, const char *host,
			    const char *password,
			    uint privileges)
{
  ACL_USER acl_user;
  acl_user.user=strdup_root(&mem,user);
  update_hostname(&acl_user.host,strdup_root(&mem,host));
  acl_user.password=0;
  acl_user.access=privileges;
  acl_user.sort=get_sort(2,acl_user.host.hostname,acl_user.user);
  acl_user.hostname_length=(uint) strlen(acl_user.host.hostname);
  if (password)
  {
    acl_user.password=(char*) "";		// Just point at something
    get_salt_from_password(acl_user.salt,password);
  }

  VOID(push_dynamic(&acl_users,(gptr) &acl_user));
  if (!acl_user.host.hostname || acl_user.host.hostname[0] == wild_many
      && !acl_user.host.hostname[1])
    allow_all_hosts=1;			// Anyone can connect /* purecov: tested */
  qsort((gptr) dynamic_element(&acl_users,0,ACL_USER*),acl_users.elements,
	sizeof(ACL_USER),(qsort_cmp) acl_compare);

  /* We must free acl_check_hosts as its memory is mapped to acl_user */
  delete_dynamic(&acl_wild_hosts);
  hash_free(&acl_check_hosts);
  init_check_host();
}


static void acl_update_db(const char *user, const char *host, const char *db,
			  uint privileges)
{
  for (uint i=0 ; i < acl_dbs.elements ; i++)
  {
    ACL_DB *acl_db=dynamic_element(&acl_dbs,i,ACL_DB*);
    if (!acl_db->user && !user[0] ||
	acl_db->user &&
	!strcmp(user,acl_db->user))
    {
      if (!acl_db->host.hostname && !host[0] ||
	  acl_db->host.hostname && !strcmp(host,acl_db->host.hostname))
      {
	if (!acl_db->db && !db[0] ||
	    acl_db->db && !strcmp(db,acl_db->db))
	{
	  if (privileges)
	    acl_db->access=privileges;
	  else
	    delete_dynamic_element(&acl_dbs,i);
	}
      }
    }
  }
}


static void acl_insert_db(const char *user, const char *host, const char *db,
			  uint privileges)
{
  ACL_DB acl_db;
  /* The acl_cache mutex is locked by mysql_grant */
  acl_db.user=strdup_root(&mem,user);
  update_hostname(&acl_db.host,strdup_root(&mem,host));
  acl_db.db=strdup_root(&mem,db);
  acl_db.access=privileges;
  acl_db.sort=get_sort(3,acl_db.host.hostname,acl_db.db,acl_db.user);
  VOID(push_dynamic(&acl_dbs,(gptr) &acl_db));
  qsort((gptr) dynamic_element(&acl_dbs,0,ACL_DB*),acl_dbs.elements,
	sizeof(ACL_DB),(qsort_cmp) acl_compare);
}


/*****************************************************************************
** Get privilege for a host, user and db combination
*****************************************************************************/

uint acl_get(const char *host, const char *ip, const char *bin_ip,
	     const char *user, const char *db)
{
  uint host_access,db_access,i,key_length;
  db_access=0; host_access= ~0;
  char key[ACL_KEY_LENGTH],*end;
  acl_entry *entry;

  VOID(pthread_mutex_lock(&acl_cache->lock));
  memcpy_fixed(&key,bin_ip,sizeof(struct in_addr));
  end=strmov(strmov(key+sizeof(struct in_addr),user)+1,db);
  key_length=(uint) (end-key);
  if ((entry=(acl_entry*) acl_cache->search(key,key_length)))
  {
    db_access=entry->access;
    VOID(pthread_mutex_unlock(&acl_cache->lock));
    return db_access;
  }

  /*
    Check if there are some access rights for database and user
  */
  for (i=0 ; i < acl_dbs.elements ; i++)
  {
    ACL_DB *acl_db=dynamic_element(&acl_dbs,i,ACL_DB*);
    if (!acl_db->user || !strcmp(user,acl_db->user))
    {
      if (compare_hostname(&acl_db->host,host,ip))
      {
	if (!acl_db->db || !wild_compare(db,acl_db->db))
	{
	  db_access=acl_db->access;
	  if (acl_db->host.hostname)
	    goto exit;				// Fully specified. Take it
	  break; /* purecov: tested */
	}
      }
    }
  }
  if (!db_access)
    goto exit;					// Can't be better

  /*
    No host specified for user. Get hostdata from host table
  */
  host_access=0;				// Host must be found
  for (i=0 ; i < acl_hosts.elements ; i++)
  {
    ACL_HOST *acl_host=dynamic_element(&acl_hosts,i,ACL_HOST*);
    if (compare_hostname(&acl_host->host,host,ip))
    {
      if (!acl_host->db || !wild_compare(db,acl_host->db))
      {
	host_access=acl_host->access;		// Fully specified. Take it
	break;
      }
    }
  }
exit:
  /* Save entry in cache for quick retrieval */
  if ((entry= (acl_entry*) malloc(sizeof(acl_entry)+key_length)))
  {
    entry->access=(db_access & host_access);
    entry->length=key_length;
    memcpy((gptr) entry->key,key,key_length);
    acl_cache->add(entry);
  }
  VOID(pthread_mutex_unlock(&acl_cache->lock));
  return (db_access & host_access);
}


int wild_case_compare(const char *str,const char *wildstr)
{
  reg3 int flag;
  DBUG_ENTER("wild_case_compare");

  while (*wildstr)
  {
    while (*wildstr && *wildstr != wild_many && *wildstr != wild_one)
    {
      if (*wildstr == wild_prefix && wildstr[1])
	wildstr++;
      if (toupper(*wildstr++) != toupper(*str++)) DBUG_RETURN(1);
    }
    if (! *wildstr ) DBUG_RETURN (*str != 0);
    if (*wildstr++ == wild_one)
    {
      if (! *str++) DBUG_RETURN (1);	/* One char; skipp */
    }
    else
    {						/* Found '*' */
      if (!*wildstr) DBUG_RETURN(0);		/* '*' as last char: OK */
      flag=(*wildstr != wild_many && *wildstr != wild_one);
      do
      {
	if (flag)
	{
	  char cmp;
	  if ((cmp= *wildstr) == wild_prefix && wildstr[1])
	    cmp=wildstr[1];
	  cmp=toupper(cmp);
	  while (*str && toupper(*str) != cmp)
	    str++;
	  if (!*str) DBUG_RETURN (1);
	}
	if (wild_case_compare(str,wildstr) == 0) DBUG_RETURN (0);
      } while (*str++);
      DBUG_RETURN(1);
    }
  }
  DBUG_RETURN (*str != '\0');
}

/*****************************************************************************
** check if there are any possible matching entries for this host
** All host names without wild cards are stored in a hash table,
** entries with wildcards are stored in a dynamic array
*****************************************************************************/

static void init_check_host(void)
{
  DBUG_ENTER("init_check_host");
  VOID(init_dynamic_array(&acl_wild_hosts,sizeof(struct acl_host_and_ip),
			  acl_users.elements,1));
  VOID(hash_init(&acl_check_hosts,acl_users.elements,0,0,
		 (hash_get_key) check_get_key,0,HASH_CASE_INSENSITIVE));
  if (!allow_all_hosts)
  {
    for (uint i=0 ; i < acl_users.elements ; i++)
    {
      ACL_USER *acl_user=dynamic_element(&acl_users,i,ACL_USER*);
      if (strchr(acl_user->host.hostname,wild_many) ||
	  strchr(acl_user->host.hostname,wild_one) ||
	  acl_user->host.ip_mask)
      {						// Has wildcard
	uint j;
	for (j=0 ; j < acl_wild_hosts.elements ; j++)
	{					// Check if host already exists
	  acl_host_and_ip *acl=dynamic_element(&acl_wild_hosts,j,
					       acl_host_and_ip *);
	  if (!my_strcasecmp(acl_user->host.hostname,acl->hostname))
	    break;				// already stored
	}
	if (j == acl_wild_hosts.elements)	// If new
	  (void) push_dynamic(&acl_wild_hosts,(char*) &acl_user->host);
      }
      else if (!hash_search(&acl_check_hosts,(byte*) &acl_user->host,
			    (uint) strlen(acl_user->host.hostname)))
      {
	if (hash_insert(&acl_check_hosts,(byte*) acl_user))
	{					// End of memory
	  allow_all_hosts=1;			// Should never happen
	  DBUG_VOID_RETURN;
	}
      }
    }
  }
  freeze_size(&acl_wild_hosts);
  freeze_size(&acl_check_hosts.array);
  DBUG_VOID_RETURN;
}


/* Return true if there is no users that can match the given host */

bool acl_check_host(const char *host, const char *ip)
{
  if (allow_all_hosts)
    return 0;
  VOID(pthread_mutex_lock(&acl_cache->lock));

  if (host && hash_search(&acl_check_hosts,(byte*) host,(uint) strlen(host)) ||
      ip && hash_search(&acl_check_hosts,(byte*) ip,(uint) strlen(ip)))
  {
    VOID(pthread_mutex_unlock(&acl_cache->lock));
    return 0;					// Found host
  }
  for (uint i=0 ; i < acl_wild_hosts.elements ; i++)
  {
    acl_host_and_ip *acl=dynamic_element(&acl_wild_hosts,i,acl_host_and_ip*);
    if (compare_hostname(acl, host, ip))
    {
      VOID(pthread_mutex_unlock(&acl_cache->lock));
      return 0;					// Host ok
    }
  }
  VOID(pthread_mutex_unlock(&acl_cache->lock));
  return 1;					// Host is not allowed
}

/*****************************************************************************
** Change password for the user if it's not an anonymous user
** Note: This should write the error directly to the client!
*****************************************************************************/

bool change_password(THD *thd, const char *host, const char *user,
		     char *new_password)
{
  uint length=0;
  if (!user[0])
  {
    send_error(&thd->net, ER_PASSWORD_ANONYMOUS_USER);
    return 1;
  }
  if (!initialized)
  {
    send_error(&thd->net, ER_PASSWORD_NOT_ALLOWED); /* purecov: inspected */
    return 1; /* purecov: inspected */
  }
  if (!host)
    host=thd->ip; /* purecov: tested */
  /* password should always be 0 or 16 chars; simple hack to avoid cracking */
  length=(uint) strlen(new_password);
  new_password[length & 16]=0;

  if (!thd || strcmp(thd->user,user) ||
      my_strcasecmp(host,thd->host ? thd->host : thd->ip))
  {
    if (check_access(thd, UPDATE_ACL, "mysql",0,1))
      return 1;
  }
  VOID(pthread_mutex_lock(&acl_cache->lock));
  ACL_USER *acl_user;
  if (!(acl_user= find_acl_user(host,user)) || !acl_user->user)
  {
    send_error(&thd->net, ER_PASSWORD_NO_MATCH);
    VOID(pthread_mutex_unlock(&acl_cache->lock));
    return 1;
  }
  if (update_user_table(thd,
			acl_user->host.hostname ? acl_user->host.hostname : "",
			acl_user->user, new_password))
  {
    VOID(pthread_mutex_unlock(&acl_cache->lock)); /* purecov: deadcode */
    send_error(&thd->net,0); /* purecov: deadcode */
    return 1; /* purecov: deadcode */
  }
  get_salt_from_password(acl_user->salt,new_password);
  if (!new_password[0])
    acl_user->password=0;
  else
    acl_user->password=(char*) "";		// Point at something
  acl_cache->clear(1);				// Clear locked hostname cache
  VOID(pthread_mutex_unlock(&acl_cache->lock));

  char buff[460];
  
  Query_log_event qinfo(thd, buff);
  qinfo.q_len =
    my_sprintf(buff,
	       (buff,"SET PASSWORD FOR \"%-.120s\"@\"%-.120s\"=\"%-.120s\"",
		acl_user->user,
		acl_user->host.hostname ? acl_user->host.hostname : "",
		new_password));
  mysql_update_log.write(thd,buff,qinfo.q_len);
  mysql_bin_log.write(&qinfo);
  return 0;
}


/*
  Find first entry that matches the current user
*/

static ACL_USER *
find_acl_user(const char *host, const char *user)
{
  for (uint i=0 ; i < acl_users.elements ; i++)
  {
    ACL_USER *acl_user=dynamic_element(&acl_users,i,ACL_USER*);
    if (!acl_user->user && !user[0] ||
	acl_user->user && !strcmp(user,acl_user->user))
    {
      if (compare_hostname(&acl_user->host,host,host))
	return acl_user;
    }
  }
  return 0;
}

/*****************************************************************************
	Handle comparing of hostname
	A hostname may be of type:
	hostname   (May include wildcards);   monty.pp.sci.fi
	ip	   (May include wildcards);   192.168.0.0
	ip/netmask			      192.168.0.0/255.255.255.0

	A net mask of 0.0.0.0 is not allowed.
*****************************************************************************/

static const char *calc_ip(const char *ip, long *val, char end)
{
  long ip_val,tmp;
  if (!(ip=str2int(ip,10,0,255,&ip_val)) || *ip != '.')
    return 0;
  ip_val<<=24;
  if (!(ip=str2int(ip+1,10,0,255,&tmp)) || *ip != '.')
    return 0;
  ip_val+=tmp<<16;
  if (!(ip=str2int(ip+1,10,0,255,&tmp)) || *ip != '.')
    return 0;
  ip_val+=tmp<<8;
  if (!(ip=str2int(ip+1,10,0,255,&tmp)) || *ip != end)
    return 0;
  *val=ip_val+tmp;
  return ip;
}


static void update_hostname(acl_host_and_ip *host, const char *hostname)
{
  host->hostname=(char*) hostname;		// This will not be modified!
  if (hostname &&
      (!(hostname=calc_ip(hostname,&host->ip,'/')) ||
       !(hostname=calc_ip(hostname+1,&host->ip_mask,'\0'))))
  {
    host->ip=host->ip_mask=0;			// Not a masked ip
  }
}


static bool compare_hostname(const acl_host_and_ip *host, const char *hostname,
			     const char *ip)
{
  long tmp;
  if (host->ip_mask && ip && calc_ip(ip,&tmp,'\0'))
  {
    return (tmp & host->ip_mask) == host->ip;
  }
  return (!host->hostname ||
	  (hostname && !wild_case_compare(hostname,host->hostname)) ||
	  (ip && !wild_compare(ip,host->hostname)));
}


/****************************************************************************
** Code to update grants in the user and database privilege tables
****************************************************************************/

static bool update_user_table(THD *thd, const char *host, const char *user,
			      const char *new_password)
{
  TABLE_LIST tables;
  TABLE *table;
  bool error=1;
  DBUG_ENTER("update_user_table");
  DBUG_PRINT("enter",("user: %s  host: %s",user,host));

  bzero((char*) &tables,sizeof(tables));
  tables.name=tables.real_name=(char*) "user";
  tables.db=(char*) "mysql";
  if (!(table=open_ltable(thd,&tables,TL_WRITE)))
    DBUG_RETURN(1); /* purecov: deadcode */
  table->field[0]->store(host,(uint) strlen(host));
  table->field[1]->store(user,(uint) strlen(user));

  if (table->file->index_read_idx(table->record[0],0,
				  (byte*) table->field[0]->ptr,0,
				  HA_READ_KEY_EXACT))
  {
    my_error(ER_PASSWORD_NO_MATCH,MYF(0));	/* purecov: deadcode */
    DBUG_RETURN(1);				/* purecov: deadcode */
  }
  store_record(table,1);
  table->field[2]->store(new_password,(uint) strlen(new_password));
  if ((error=table->file->update_row(table->record[1],table->record[0])))
  {
    table->file->print_error(error,MYF(0));	/* purecov: deadcode */
    goto end;					/* purecov: deadcode */
  }
  error=0;					// Record updated

end:
  close_thread_tables(thd);
  DBUG_RETURN(error);
}

/****************************************************************************
** Handle GRANT commands
****************************************************************************/

static int replace_user_table(TABLE *table, const LEX_USER &combo,
			      uint rights, char what)
{
  int error = -1;
  uint i,j;
  bool ima=0;
  char *password,empty_string[1];
  DBUG_ENTER("replace_user_table");

  if (combo.password.str && combo.password.str[0])
    password=combo.password.str;
  else
  {
    password=empty_string;
    empty_string[0]=0;
  }

  table->field[0]->store(combo.host.str,combo.host.length);
  table->field[1]->store(combo.user.str,combo.user.length);
  table->file->index_init(0);
  if (table->file->index_read(table->record[0],
			      (byte*) table->field[0]->ptr,0,
			      HA_READ_KEY_EXACT))
  {
    if (what == 'N')
    {
      my_printf_error(ER_NONEXISTING_GRANT,ER(ER_NONEXISTING_GRANT),
		      MYF(0),combo.user.str,combo.host.str);
      error= -1;
      goto end;
    }
    ima = 0; // no row; ima on Serbian means 'there is something'
    restore_record(table,2);			// cp empty row from record[2]
    table->field[0]->store(combo.host.str,combo.host.length);
    table->field[1]->store(combo.user.str,combo.user.length);
    table->field[2]->store(password,(uint) strlen(password));
  }
  else
  {
    ima = 1;
    store_record(table,1);			// Save copy for update
    if (combo.password.str)			// If password given
      table->field[2]->store(password,(uint) strlen(password));
  }

  for (i = 3, j = SELECT_ACL;			// starting from reload
       i < table->fields;
       i++, j <<= 1)
  {
    if (j & rights)				 // set requested privileges
      table->field[i]->store(&what,1);
  }
  rights=get_access(table,3);

  if (ima)  // there is a row, therefore go to update, instead of insert
  {
    /*
      We should NEVER delete from the user table, as a uses can still
      use mysqld even if he doesn't have any privileges in the user table!
    */
    if (cmp_record(table,1) &&
	(error=table->file->update_row(table->record[1],table->record[0])))
    {						// This should never happen
      table->file->print_error(error,MYF(0));	/* purecov: deadcode */
      error= -1;				/* purecov: deadcode */
      goto end;					/* purecov: deadcode */
    }
  }
  else if ((error=table->file->write_row(table->record[0]))) // insert
  {						// This should never happen
    if (error && error != HA_ERR_FOUND_DUPP_KEY &&
	error != HA_ERR_FOUND_DUPP_UNIQUE)	/* purecov: inspected */
    {
      table->file->print_error(error,MYF(0));	/* purecov: deadcode */
      error= -1;				/* purecov: deadcode */
      goto end;					/* purecov: deadcode */
    }
  }
  error=0;					// Privileges granted / revoked

 end:
  if (!error)
  {
    acl_cache->clear(1);			// Clear privilege cache
    if (!combo.password.str)
      password=0;				// No password given on command
    if (ima)
      acl_update_user(combo.user.str,combo.host.str,password,rights);
    else
      acl_insert_user(combo.user.str,combo.host.str,password,rights);
  }
  table->file->index_end();
  DBUG_RETURN(error);
}


/*
** change grants in the mysql.db table
*/

static int replace_db_table(TABLE *table, const char *db,
			    const LEX_USER &combo,
			    uint rights, char what)
{
  uint i,j,store_rights;
  bool ima=0;
  int error;
  DBUG_ENTER("replace_db_table");

  // is there such a user in user table in memory ????
  if (!initialized || !find_acl_user(combo.host.str,combo.user.str))
  {
    my_error(ER_PASSWORD_NO_MATCH,MYF(0));
    DBUG_RETURN(-1);
  }

  table->field[0]->store(combo.host.str,combo.host.length);
  table->field[1]->store(db,(uint) strlen(db));
  table->field[2]->store(combo.user.str,combo.user.length);
  table->file->index_init(0);
  if (table->file->index_read(table->record[0],(byte*) table->field[0]->ptr,0,
	      HA_READ_KEY_EXACT))
  {
    if (what == 'N')
    { // no row, no revoke
      my_printf_error(ER_NONEXISTING_GRANT,ER(ER_NONEXISTING_GRANT),MYF(0),
		      combo.user.str,combo.host.str);
      goto abort;
    }
    ima = 0; // no row
    restore_record(table,2);			// cp empty row from record[2]
    table->field[0]->store(combo.host.str,combo.host.length);
    table->field[1]->store(db,(uint) strlen(db));
    table->field[2]->store(combo.user.str,combo.user.length);
  }
  else
  {
    ima = 1;
    store_record(table,1);
  }

  store_rights=get_rights_for_db(rights);
  for (i = 3, j = 1; i < table->fields; i++, j <<= 1)
  {
    if (j & store_rights)			// do it if priv is chosen
      table->field [i]->store(&what,1);		// set requested privileges
  }
  rights=get_access(table,3);
  rights=fix_rights_for_db(rights);

  if (ima) // there is a row, therefore go update, else insert
  {
    if (rights)
    {
      if ((error=table->file->update_row(table->record[1],table->record[0])))
	goto table_error;			/* purecov: deadcode */
    }
    else	/* must have been a revoke of all privileges */
    {
      if ((error = table->file->delete_row(table->record[1])))
	goto table_error;			/* purecov: deadcode */
    }
  }
  else if ((error=table->file->write_row(table->record[0])))
  {
    if (error && error != HA_ERR_FOUND_DUPP_KEY) /* purecov: inspected */
      goto table_error; /* purecov: deadcode */
  }

  acl_cache->clear(1);				// Clear privilege cache
  if (ima)
    acl_update_db(combo.user.str,combo.host.str,db,rights);
  else
    acl_insert_db(combo.user.str,combo.host.str,db,rights);
  table->file->index_end();
  DBUG_RETURN(0);

  /* This could only happen if the grant tables got corrupted */
 table_error:
  table->file->print_error(error,MYF(0));	/* purecov: deadcode */
  table->file->index_end();

 abort:
  DBUG_RETURN(-1);
}


class GRANT_COLUMN :public Sql_alloc
{
public:
  char *column;
  uint rights, key_length;
  GRANT_COLUMN(String &c,  uint y) :rights (y)
  {
    column= memdup_root(&memex,c.ptr(),key_length=c.length());
  }
};

static byte* get_key_column(GRANT_COLUMN *buff,uint *length,
			    my_bool not_used __attribute__((unused)))
{
  *length=buff->key_length;
  return (byte*) buff->column;
}

class GRANT_TABLE :public Sql_alloc
{
public:
  char *host,*db,*user,*tname, *hash_key;
  uint privs, cols, key_length;
  HASH hash_columns;
  GRANT_TABLE (const char *h, const char *d,const char *u, const char *t,
	       uint p,uint c)
    : privs(p), cols(c)
  {
    host = strdup_root(&memex,h);
    db =   strdup_root(&memex,d);
    user = strdup_root(&memex,u);
    tname= strdup_root(&memex,t);
    key_length =(uint) strlen(d)+(uint) strlen(u)+(uint) strlen(t)+3;
    hash_key = (char*) alloc_root(&memex,key_length);
    strmov(strmov(strmov(hash_key,user)+1,db)+1,tname);
    (void) hash_init(&hash_columns,0,0,0, (hash_get_key) get_key_column,0,
		     HASH_CASE_INSENSITIVE);
  }

  GRANT_TABLE (TABLE *form, TABLE *col_privs)
  {
    byte key[MAX_KEY_LENGTH];

    host =  get_field(&memex,form,0);
    db =    get_field(&memex,form,1);
    user =  get_field(&memex,form,2);  if (!user) user=(char*) "";
    tname = get_field(&memex,form,3);
    if (!host || !db || !tname)
    {
      /* Wrong table row; Ignore it */
      privs = cols = 0;				/* purecov: inspected */
      return;					/* purecov: inspected */
    }
    key_length = (uint) strlen(db) + (uint) strlen(user) + (uint) strlen (tname) + 3;
    hash_key = (char*) alloc_root(&memex,key_length);
    strmov(strmov(strmov(hash_key,user)+1,db)+1,tname);
    privs = (uint) form->field[6]->val_int();
    cols  = (uint) form->field[7]->val_int();
    privs = fix_rights_for_table(privs);
    cols =  fix_rights_for_column(cols);

    (void) hash_init(&hash_columns,0,0,0, (hash_get_key) get_key_column,0,
		     HASH_CASE_INSENSITIVE);
    if (cols)
    {
      int key_len;
      col_privs->field[0]->store(host,(uint) strlen(host));
      col_privs->field[1]->store(db,(uint) strlen(db));
      col_privs->field[2]->store(user,(uint) strlen(user));
      col_privs->field[3]->store(tname,(uint) strlen(tname));
      key_len=(col_privs->field[0]->pack_length()+
	       col_privs->field[1]->pack_length()+
	       col_privs->field[2]->pack_length()+
	       col_privs->field[3]->pack_length());
      key_copy(key,col_privs,0,key_len);
      col_privs->field[4]->store("",0);
      col_privs->file->index_init(0);
      if (col_privs->file->index_read(col_privs->record[0],
				      (byte*) col_privs->field[0]->ptr,
				      key_len, HA_READ_KEY_EXACT))
      {
	cols = 0; /* purecov: deadcode */
	return;
      }
      do
      {
	String *res,column_name;
	GRANT_COLUMN *mem_check;
	/* As column name is a string, we don't have to supply a buffer */
	res=col_privs->field[4]->val_str(&column_name,&column_name);
	uint priv= (uint) col_privs->field[6]->val_int();
	if (!(mem_check = new GRANT_COLUMN(*res,
					   fix_rights_for_column(priv))))
	{
	  // Don't use this entry
	  privs = cols = 0;			/* purecov: deadcode */
	  return;				/* purecov: deadcode */
	}
	hash_insert(&hash_columns, (byte *) mem_check);
      } while (!col_privs->file->index_next(col_privs->record[0]) &&
	       !key_cmp(col_privs,key,0,key_len));
    }
  }
  bool ok() { return privs != 0 || cols != 0; }
};

static byte* get_grant_table(GRANT_TABLE *buff,uint *length,
			     my_bool not_used __attribute__((unused)))
{
  *length=buff->key_length;
  return (byte*) buff->hash_key;
}

void free_grant_table(GRANT_TABLE *grant_table)
{
  hash_free(&grant_table->hash_columns);
}

/* Search after a matching grant. Prefer exact grants before not exact ones */

static GRANT_TABLE *table_hash_search(const char *host,const char* ip,
				      const char *db,
				      const char *user, const char *tname,
				      bool exact)
{
  char helping [NAME_LEN*2+USERNAME_LENGTH+3];
  uint len;
  GRANT_TABLE *grant_table,*found=0;

  len  = (uint) (strmov(strmov(strmov(helping,user)+1,db)+1,tname)-helping)+ 1;
  for (grant_table=(GRANT_TABLE*) hash_search(&hash_tables,(byte*) helping,
					      len) ;
       grant_table ;
       grant_table= (GRANT_TABLE*) hash_next(&hash_tables,(byte*) helping,len))
  {
    if (exact)
    {
      if ((host && !strcmp(host,grant_table->host)) ||
	  (ip && !strcmp(ip,grant_table->host)))
	return grant_table;
    }
    else
    {
      if ((host && !wild_case_compare(host,grant_table->host)) ||
	  (ip && !wild_case_compare(ip,grant_table->host)))
	found=grant_table;					// Host ok
    }
  }
  return found;
}



static inline GRANT_COLUMN *
column_hash_search(GRANT_TABLE *t, const char *cname,
					uint length)
{
  return (GRANT_COLUMN*) hash_search(&t->hash_columns, (byte*) cname,length);
}


static int replace_column_table(GRANT_TABLE *g_t,
				TABLE *table, const LEX_USER &combo,
				List <LEX_COLUMN> &columns,
				const char *db, const char *table_name,
				uint rights, bool revoke_grant)
{
  int error=0,result=0;
  uint key_length;
  byte key[MAX_KEY_LENGTH];
  DBUG_ENTER("replace_column_table");

  table->field[0]->store(combo.host.str,combo.host.length);
  table->field[1]->store(db,(uint) strlen(db));
  table->field[2]->store(combo.user.str,combo.user.length);
  table->field[3]->store(table_name,(uint) strlen(table_name));
  key_length=(table->field[0]->pack_length()+ table->field[1]->pack_length()+
	      table->field[2]->pack_length()+ table->field[3]->pack_length());
  key_copy(key,table,0,key_length);

  rights &= COL_ACLS;				// Only ACL for columns

  /* first fix privileges for all columns in column list */

  List_iterator <LEX_COLUMN> iter(columns);
  class LEX_COLUMN *xx;
  table->file->index_init(0);
  while ((xx=iter++))
  {
    uint privileges = xx->rights;
    bool ima=0;
    key_restore(table,key,0,key_length);
    table->field[4]->store(xx->column.ptr(),xx->column.length());

    if (table->file->index_read(table->record[0],(byte*) table->field[0]->ptr,
				0, HA_READ_KEY_EXACT))
    {
      if (revoke_grant)
      {
	my_printf_error(ER_NONEXISTING_TABLE_GRANT,
			ER(ER_NONEXISTING_TABLE_GRANT),MYF(0),
			combo.user.str, combo.host.str,table_name); /* purecov: inspected */
	result= -1; /* purecov: inspected */
	continue; /* purecov: inspected */
      }
      ima = 0;
      restore_record(table,2);			// Get empty record
      key_restore(table,key,0,key_length);
      table->field[4]->store(xx->column.ptr(),xx->column.length());
    }
    else
    {
      uint tmp= (uint) table->field[6]->val_int();
      tmp=fix_rights_for_column(tmp);

      if (revoke_grant)
	privileges = tmp & ~(privileges | rights);
      else
	privileges |= tmp;
      ima = 1;
      store_record(table,1);			// copy original row
    }

    table->field[6]->store((longlong) get_rights_for_column(privileges));

    if (ima) // there is a row, therefore go update, else insert
    {
      if (privileges)
	error=table->file->update_row(table->record[1],table->record[0]);
      else
	error=table->file->delete_row(table->record[1]);
      if (error)
      {
	table->file->print_error(error,MYF(0)); /* purecov: inspected */
	result= -1;				/* purecov: inspected */
	goto end;				/* purecov: inspected */
      }
      GRANT_COLUMN *grant_column = column_hash_search(g_t,
						      xx->column.ptr(),
						      xx->column.length());
      if (grant_column)				// Should always be true
	grant_column->rights = privileges;	// Update hash
    }
    else					// new grant
    {
      if ((error=table->file->write_row(table->record[0])))
      {
	table->file->print_error(error,MYF(0)); /* purecov: inspected */
	result= -1;				/* purecov: inspected */
	goto end;				/* purecov: inspected */
      }
      GRANT_COLUMN *grant_column = new GRANT_COLUMN(xx->column,privileges);
      hash_insert(&g_t->hash_columns,(byte*) grant_column);
    }
  }
  table->file->index_end();

  /*
    If revoke of privileges on the table level, remove all such privileges
    for all columns
  */

  if (revoke_grant)
  {
    table->file->index_init(0);
    if (table->file->index_read(table->record[0], (byte*) table->field[0]->ptr,
				key_length, HA_READ_KEY_EXACT))
      goto end;

    // Scan trough all rows with the same host,db,user and table
    do
    {
      uint privileges = (uint) table->field[6]->val_int();
      privileges=fix_rights_for_column(privileges);
      store_record(table,1);

      if (privileges & rights)	// is in this record the priv to be revoked ??
      {
	GRANT_COLUMN *grant_column = NULL;
	char  colum_name_buf[HOSTNAME_LENGTH+1];
	String column_name(colum_name_buf,sizeof(colum_name_buf));

	privileges&= ~rights;
	table->field[6]->store((longlong)
			       get_rights_for_column(privileges));
	table->field[4]->val_str(&column_name,&column_name);
	grant_column = column_hash_search(g_t,
					  column_name.ptr(),
					  column_name.length());
	if (privileges)
	{
	  int tmp_error;
	  if ((tmp_error=table->file->update_row(table->record[1],
						 table->record[0])))
	  {					/* purecov: deadcode */
	    table->file->print_error(tmp_error,MYF(0)); /* purecov: deadcode */
	    result= -1;				/* purecov: deadcode */
	    goto end;				/* purecov: deadcode */
	  }
	  if (grant_column)
	    grant_column->rights  = privileges; // Update hash
	}
	else
	{
	  int tmp_error;
	  if ((tmp_error = table->file->delete_row(table->record[1])))
	  {					/* purecov: deadcode */
	    table->file->print_error(tmp_error,MYF(0)); /* purecov: deadcode */
	    result= -1;				/* purecov: deadcode */
	    goto end;				/* purecov: deadcode */
	  }
	  if (grant_column)
	    hash_delete(&g_t->hash_columns,(byte*) grant_column);
	}
      }
    } while (!table->file->index_next(table->record[0]) &&
	     !key_cmp(table,key,0,key_length));
  }

 end:
  table->file->index_end();
  DBUG_RETURN(result);
}


static int replace_table_table(THD *thd, GRANT_TABLE *grant_table,
			       TABLE *table, const LEX_USER &combo,
			       const char *db, const char *table_name,
			       uint rights, uint kolone, bool revoke_grant)
{
  char grantor[HOSTNAME_LENGTH+1+USERNAME_LENGTH];
  int ima = 1;
  int error=0;
  uint store_table_rights,store_col_rights;
  DBUG_ENTER("replace_table_table");

  strxmov(grantor,thd->user,"@",thd->host ? thd->host : thd->ip ? thd->ip :"",
	  NullS);

  // The following should always succeed as new users are created before
  // this function is called!
  if (!find_acl_user(combo.host.str,combo.user.str))
  {
    my_error(ER_PASSWORD_NO_MATCH,MYF(0));	/* purecov: deadcode */
    DBUG_RETURN(-1);				/* purecov: deadcode */
  }

  restore_record(table,2);			// Get empty record
  table->field[0]->store(combo.host.str,combo.host.length);
  table->field[1]->store(db,(uint) strlen(db));
  table->field[2]->store(combo.user.str,combo.user.length);
  table->field[3]->store(table_name,(uint) strlen(table_name));
  store_record(table,1);			// store at pos 1

  if (table->file->index_read_idx(table->record[0],0,
				  (byte*) table->field[0]->ptr,0,
				  HA_READ_KEY_EXACT))
  {
    /*
      The following should never happen as we first check the in memory
      grant tables for the user.  There is however always a small change that
      the user has modified the grant tables directly.
    */
    if (revoke_grant)
    { // no row, no revoke
      my_printf_error(ER_NONEXISTING_TABLE_GRANT,
		      ER(ER_NONEXISTING_TABLE_GRANT),MYF(0),
		      combo.user.str,combo.host.str,
		      table_name);		/* purecov: deadcode */
      DBUG_RETURN(-1);				/* purecov: deadcode */
    }
    ima = 0;					// no row
    restore_record(table,1);			// Get saved record
  }

  store_table_rights=get_rights_for_table(rights);
  store_col_rights=get_rights_for_column(kolone);
  if (ima)
  {
    uint j,k;
    store_record(table,1);
    j = (uint) table->field[6]->val_int();
    k = (uint) table->field[7]->val_int();

    if (revoke_grant)
    {
      // column rights are already fixed in mysql_table_grant !
      store_table_rights=j & ~store_table_rights;
    }
    else
    {
      store_table_rights|=j;
      store_col_rights|=k;
    }
  }

  table->field[4]->store(grantor,(uint) strlen(grantor));
  table->field[6]->store((longlong) store_table_rights);
  table->field[7]->store((longlong) store_col_rights);
  rights=fix_rights_for_table(store_table_rights);
  kolone=fix_rights_for_column(store_col_rights);

  if (ima) // there is a row, therefore go update, else insert
  {
    if (store_table_rights || store_col_rights)
    {
      if ((error=table->file->update_row(table->record[1],table->record[0])))
	goto table_error;			/* purecov: deadcode */
    }
    else if ((error = table->file->delete_row(table->record[1])))
      goto table_error;				/* purecov: deadcode */
  }
  else
  {
    error=table->file->write_row(table->record[0]);
    if (error && error != HA_ERR_FOUND_DUPP_KEY)
      goto table_error;				/* purecov: deadcode */
  }

  if (rights | kolone)
  {
    grant_table->privs = rights;
    grant_table->cols = kolone;
  }
  else
  {
    hash_delete(&hash_tables,(byte*) grant_table);
  }
  DBUG_RETURN(0);

 /* This should never happen */
 table_error:
  table->file->print_error(error,MYF(0)); /* purecov: deadcode */
  DBUG_RETURN(-1); /* purecov: deadcode */
}


int mysql_table_grant (THD *thd, TABLE_LIST *table_list,
		       List <LEX_USER> &user_list,
		       List <LEX_COLUMN> &columns, uint rights,
		       bool revoke_grant)
{
  uint column_priv = 0;
  List_iterator <LEX_USER> str_list (user_list);
  LEX_USER *Str;
  TABLE_LIST tables[3];
  DBUG_ENTER("mysql_table_grant");

  if (!initialized)
  {
    send_error(&(thd->net), ER_UNKNOWN_COM_ERROR); /* purecov: inspected */
    return 1;					/* purecov: inspected */
  }
  if (rights & ~TABLE_ACLS)
  {
    my_error(ER_ILLEGAL_GRANT_FOR_TABLE,MYF(0));
    DBUG_RETURN(-1);
  }

  if (columns.elements && !revoke_grant)
  {
    TABLE *table;
    class LEX_COLUMN *check;
    List_iterator <LEX_COLUMN> iter(columns);

    if (!(table=open_ltable(thd,table_list,TL_READ)))
      DBUG_RETURN(-1);
    while ((check = iter++))
    {
      if (!find_field_in_table(thd,table,check->column.ptr(),
			       check->column.length(),0,0))
      {
	my_printf_error(ER_BAD_FIELD_ERROR,ER(ER_BAD_FIELD_ERROR),MYF(0),
			check->column.c_ptr(),table_list->name);
	DBUG_RETURN(-1);
      }
      column_priv |= check->rights | (rights & COL_ACLS);
    }
    close_thread_tables(thd);
  }
  else if (!(rights & CREATE_ACL) && !revoke_grant)
  {
    char buf[FN_REFLEN];
    sprintf(buf,"%s/%s/%s.frm",mysql_data_home,table_list->db,
	    table_list->name);
    fn_format(buf,buf,"","",4+16+32);
    if (access(buf,F_OK))
    {
      my_error(ER_NO_SUCH_TABLE,MYF(0),table_list->db,table_list->name);
      DBUG_RETURN(-1);
    }
  }

  /* open the mysql.tables_priv and mysql.columns_priv tables */

  bzero((char*) &tables,sizeof(tables));
  tables[0].name=tables[0].real_name= (char*) "user";
  tables[1].name=tables[1].real_name= (char*) "tables_priv";
  tables[2].name=tables[2].real_name= (char*) "columns_priv";
  tables[0].next=tables+1;
  /* Don't open column table if we don't need it ! */
  tables[1].next=((column_priv ||
		   (revoke_grant && ((rights & COL_ACLS) || columns.elements)))
		  ? tables+2 : 0);
  tables[0].lock_type=tables[1].lock_type=tables[2].lock_type=TL_WRITE;
  tables[0].db=tables[1].db=tables[2].db=(char*) "mysql";

  if (open_and_lock_tables(thd,tables))
  {						// Should never happen
    close_thread_tables(thd);			/* purecov: deadcode */
    DBUG_RETURN(-1);				/* purecov: deadcode */
  }

  int result=0;
  pthread_mutex_lock(&LOCK_grant);
  MEM_ROOT *old_root=my_pthread_getspecific_ptr(MEM_ROOT*,THR_MALLOC);
  my_pthread_setspecific_ptr(THR_MALLOC,&memex);

  while ((Str = str_list++))
  {
    GRANT_TABLE *grant_table;
    if (!Str->host.str)
    {
      Str->host.str=(char*) "%";
      Str->host.length=1;
    }
    if (Str->host.length > HOSTNAME_LENGTH ||
	Str->user.length > USERNAME_LENGTH)
    {
      my_error(ER_GRANT_WRONG_HOST_OR_USER,MYF(0));
      result= -1;
      continue;
    }
    /* Create user if needed */
    if ((replace_user_table(tables[0].table,
			    *Str,
			    0,
			    revoke_grant ? 'N' : 'Y')))
    {
      result= -1;				// Remember error
      continue;					// Add next user
    }

    /* Find/create cached table grant */
    grant_table= table_hash_search(Str->host.str,NullS,table_list->db,
				   Str->user.str,
				   table_list->name,1);
    if (!grant_table)
    {
      if (revoke_grant)
      {
	my_printf_error(ER_NONEXISTING_TABLE_GRANT,
			ER(ER_NONEXISTING_TABLE_GRANT),MYF(0),
			Str->user.str, Str->host.str,table_list->name);
	result= -1;
	continue;
      }
      grant_table = new GRANT_TABLE (Str->host.str,table_list->db,
				     Str->user.str,
				     table_list->name,
				     rights,
				     column_priv);
      if (!grant_table)				// end of memory
      {
	result= -1;				/* purecov: deadcode */
	continue;				/* purecov: deadcode */
      }
      hash_insert(&hash_tables,(byte*) grant_table);
    }

    /* If revoke_grant, calculate the new column privilege for tables_priv */
    if (revoke_grant)
    {
      class LEX_COLUMN *check;
      List_iterator <LEX_COLUMN> iter(columns);
      GRANT_COLUMN *grant_column;

      /* Fix old grants */
      while ((check = iter++))
      {
	grant_column = column_hash_search(grant_table,
					  check->column.ptr(),
					  check->column.length());
	if (grant_column)
	  grant_column->rights&= ~(check->rights | rights);
      }
      /* scan trough all columns to get new column grant */
      column_priv=0;
      for (uint idx=0 ; idx < grant_table->hash_columns.records ; idx++)
      {
	grant_column= (GRANT_COLUMN*) hash_element(&grant_table->hash_columns,
						   idx);
	grant_column->rights&= ~rights;		// Fix other columns
	column_priv|= grant_column->rights;
      }
    }
    else
    {
      column_priv|= grant_table->cols;
    }


    /* update table and columns */

    if (replace_table_table(thd,grant_table,tables[1].table,*Str,
			    table_list->db,
			    table_list->name,
			    rights, column_priv, revoke_grant))
    {						// Crashend table ??
      result= -1;			       /* purecov: deadcode */
    }
    else if (tables[2].table)
    {
      if ((replace_column_table(grant_table,tables[2].table, *Str,
				columns,
				table_list->db,
				table_list->name,
				rights, revoke_grant)))
      {
	result= -1;
      }
    }
  }
  grant_option=TRUE;
  my_pthread_setspecific_ptr(THR_MALLOC,old_root);
  pthread_mutex_unlock(&LOCK_grant);
  if (!result)
    send_ok(&thd->net);
  /* Tables are automaticly closed */
  DBUG_RETURN(result);
}


int mysql_grant (THD *thd, const char *db, List <LEX_USER> &list, uint rights,
		 bool revoke_grant)
{
  List_iterator <LEX_USER> str_list (list);
  LEX_USER *Str;
  char what;
  TABLE_LIST tables[2];
  DBUG_ENTER("mysql_grant");

  if (!initialized)
  {
    send_error(&(thd->net), ER_UNKNOWN_COM_ERROR); /* purecov: tested */
    return 1; /* purecov: tested */
  }

  what = (revoke_grant) ? 'N' : 'Y';

  /* open the mysql.user and mysql.db tables */

  tables[0].name=tables[0].real_name=(char*) "user";
  tables[1].name=tables[1].real_name=(char*) "db";
  tables[0].next=tables+1;
  tables[1].next=0;
  tables[0].lock_type=tables[1].lock_type=TL_WRITE;
  tables[0].db=tables[1].db=(char*) "mysql";
  tables[0].table=tables[1].table=0;
  if (open_and_lock_tables(thd,tables))
  {						// This should never happen
    close_thread_tables(thd);			/* purecov: deadcode */
    DBUG_RETURN(-1);				/* purecov: deadcode */
  }

 // go through users in user_list

  pthread_mutex_lock(&LOCK_grant);
  VOID(pthread_mutex_lock(&acl_cache->lock));
  grant_version++;

  int result=0;
  while ((Str = str_list++))
  {
    if (!Str->host.str)
    {
      Str->host.str=(char*) "%";
      Str->host.length=1;
    }
    if (Str->host.length > HOSTNAME_LENGTH ||
	Str->user.length > USERNAME_LENGTH)
    {
      my_error(ER_GRANT_WRONG_HOST_OR_USER,MYF(0));
      result= -1;
      continue;
    }
    if ((replace_user_table(tables[0].table,
			    *Str,
			    (!db ? rights : 0), what)))
      result= -1;
    if (db)
      if (( replace_db_table(tables[1].table, db, *Str, rights,
			     what)))
	result= -1;
  }
  VOID(pthread_mutex_unlock(&acl_cache->lock));
  pthread_mutex_unlock(&LOCK_grant);
  close_thread_tables(thd);

  if (!result)
    send_ok(&thd->net);
  DBUG_RETURN(result);
}

 /* Free grant array if possible */

void  grant_free(void)
{
  DBUG_ENTER("grant_free");
  grant_option = FALSE;
  hash_free(&hash_tables);
  free_root(&memex,MYF(0));
  DBUG_VOID_RETURN;
}


/* Init grant array if possible */

int  grant_init (void)
{
  THD  *thd;
  TABLE_LIST tables[2];
  int error = 0;
  TABLE *t_table, *c_table;
  DBUG_ENTER("grant_init");

  grant_option = FALSE;
  (void) hash_init(&hash_tables,0,0,0, (hash_get_key) get_grant_table,
		   (hash_free_key) free_grant_table,0);
  init_sql_alloc(&memex,1024,0);

  if (!initialized)
    DBUG_RETURN(0);				/* purecov: tested */
  if (!(thd=new THD))
    DBUG_RETURN(1);				/* purecov: deadcode */

  thd->version=refresh_version;
  thd->mysys_var=my_thread_var;
  thd->current_tablenr=0;
  thd->open_tables=0;
  thd->db=my_strdup("mysql",MYF(0));
  bzero((char*) &tables,sizeof(tables));
  tables[0].name=tables[0].real_name= (char*) "tables_priv";
  tables[1].name=tables[1].real_name= (char*) "columns_priv";
  tables[0].next=tables+1;
  tables[0].lock_type=tables[1].lock_type=TL_READ;
  tables[0].db=tables[1].db=thd->db;

  if (open_tables(thd,tables))
  {						// No grant tables
    close_thread_tables(thd);			/* purecov: deadcode */
    delete thd;					/* purecov: deadcode */
    DBUG_RETURN(1);				/* purecov: deadcode */
  }
  TABLE *ptr[2];				// Lock tables for quick update
  ptr[0]= tables[0].table;
  ptr[1]= tables[1].table;
  MYSQL_LOCK *lock=mysql_lock_tables(thd,ptr,2);
  if (!lock)
  {
    close_thread_tables(thd);			/* purecov: deadcode */
    delete thd;					/* purecov: deadcode */
    DBUG_RETURN(1);				/* purecov: deadcode */
  }

  t_table = tables[0].table; c_table = tables[1].table;
  t_table->file->index_init(0);
  if (t_table->file->index_first(t_table->record[0]))
  {
    t_table->file->index_end();
    mysql_unlock_tables(thd, lock);
    thd->version--;				// Force close to free memory
    close_thread_tables(thd);
    delete thd;
    DBUG_RETURN(0);				// Empty table is ok!
  }
  grant_option = TRUE;
  t_table->file->index_end();

  MEM_ROOT *old_root=my_pthread_getspecific_ptr(MEM_ROOT*,THR_MALLOC);
  my_pthread_setspecific_ptr(THR_MALLOC,&memex);
  while (!error)
  {
    GRANT_TABLE *mem_check;
    if (!(mem_check=new GRANT_TABLE(t_table,c_table)) ||
	mem_check->ok() && hash_insert(&hash_tables,(byte*) mem_check))
    {
      /* This could only happen if we are out memory */
      my_pthread_setspecific_ptr(THR_MALLOC,old_root); /* purecov: deadcode */
      grant_option = FALSE;			/* purecov: deadcode */
      mysql_unlock_tables(thd, lock);		/* purecov: deadcode */
      close_thread_tables(thd);			/* purecov: deadcode */
      delete thd;				/* purecov: deadcode */
      DBUG_RETURN(1);				/* purecov: deadcode */
    }
    error = t_table->file->index_next(t_table->record[0]);
  }
  my_pthread_setspecific_ptr(THR_MALLOC,old_root);
  mysql_unlock_tables(thd, lock);
  thd->version--;				// Force close to free memory
  close_thread_tables(thd);
  delete thd;
  DBUG_RETURN(0);
}


/* Reload grant array if possible */

void grant_reload(void)
{
  HASH old_hash_tables;bool old_grant_option;
  MEM_ROOT old_mem;
  DBUG_ENTER("grant_reload");

  // Locked tables are checked by acl_init and doesn't have to be checked here

  pthread_mutex_lock(&LOCK_grant);
  grant_version++;
  old_hash_tables=hash_tables;
  old_grant_option = grant_option;
  old_mem = memex;

  if (grant_init())
  {						// Error. Revert to old hash
    grant_free();				/* purecov: deadcode */
    hash_tables=old_hash_tables;		/* purecov: deadcode */
    grant_option = old_grant_option;		/* purecov: deadcode */
    memex = old_mem;				/* purecov: deadcode */
  }
  else
  {
    hash_free(&old_hash_tables);
    free_root(&old_mem,MYF(0));
  }
  pthread_mutex_unlock(&LOCK_grant);
  DBUG_VOID_RETURN;
}


/****************************************************************************
** Check grants
** All errors are written directly to the client if command name is given !
****************************************************************************/

bool check_grant(THD *thd, uint want_access, TABLE_LIST *tables,
		 uint show_table)
{
  TABLE_LIST *table;
  char *user = thd->priv_user;

  want_access &= ~thd->master_access;
  if (!want_access)
    return 0;					// ok

  pthread_mutex_lock(&LOCK_grant);
  for (table=tables; table ;table=table->next)
  {
    if (!(~table->grant.privilege & want_access))
    {
      table->grant.want_privilege=0;
      continue;					// Already checked
    }
    const char *db = table->db ? table->db : thd->db;
    GRANT_TABLE *grant_table = table_hash_search(thd->host,thd->ip,db,user,
						 table->real_name,0);
    if (!grant_table)
    {
      want_access &= ~table->grant.privilege;
      goto err;					// No grants
    }
    if (show_table)
      continue;					// We have some priv on this

    table->grant.grant_table=grant_table;	// Remember for column test
    table->grant.version=grant_version;
    table->grant.privilege|= grant_table->privs;
    table->grant.want_privilege= ((want_access & COL_ACLS)
				  & ~table->grant.privilege);

    if (!(~table->grant.privilege & want_access))
      continue;

    if (want_access & ~(grant_table->cols | table->grant.privilege))
    {
      want_access &= ~(grant_table->cols | table->grant.privilege);
      goto err;					// impossible
    }
  }
  pthread_mutex_unlock(&LOCK_grant);
  return 0;

 err:
  pthread_mutex_unlock(&LOCK_grant);
  if (show_table != 1)				// Not a silent skip of table
  {
    const char *command="";
    if (want_access & SELECT_ACL)
       command ="select";
    else if (want_access & INSERT_ACL)
      command = "insert";
    else if (want_access & UPDATE_ACL)
      command = "update";
    else if (want_access & DELETE_ACL)
      command = "delete";
    else if (want_access & DROP_ACL)
      command = "drop";
    else if (want_access & CREATE_ACL)
      command = "create";
    else if (want_access & ALTER_ACL)
      command = "alter";
    else if (want_access & INDEX_ACL)
      command = "index";
    else if (want_access & GRANT_ACL)
      command = "grant";
    net_printf(&thd->net,ER_TABLEACCESS_DENIED_ERROR,
	       command,
	       thd->priv_user,
	       thd->host ? thd->host : (thd->ip ? thd->ip : "unknown"),
	       table ? table->real_name : "unknown");
  }
  return 1;
}


bool check_grant_column (THD *thd,TABLE *table, const char *name,
			 uint length, uint show_tables)
{
  GRANT_TABLE *grant_table;
  GRANT_COLUMN *grant_column;

  uint want_access=table->grant.want_privilege;
  if (!want_access)
    return 0;					// Already checked

  pthread_mutex_lock(&LOCK_grant);

  // reload table if someone has modified any grants

  if (table->grant.version != grant_version)
  {
    table->grant.grant_table=
      table_hash_search(thd->host,thd->ip,thd->db,
			thd->priv_user,
			table->real_name,0);	/* purecov: inspected */
    table->grant.version=grant_version;		/* purecov: inspected */
  }
  if (!(grant_table=table->grant.grant_table))
    goto err;					/* purecov: deadcode */

  grant_column=column_hash_search(grant_table, name, length);
  if (grant_column && !(~grant_column->rights & want_access))
  {
    pthread_mutex_unlock(&LOCK_grant);
    return 0;
  }
#ifdef NOT_USED
  if (show_tables && (grant_column || table->grant.privilege & COL_ACLS))
  {
    pthread_mutex_unlock(&LOCK_grant);		/* purecov: deadcode */
    return 0;					/* purecov: deadcode */
  }
#endif

  /* We must use my_printf_error() here! */
 err:
  pthread_mutex_unlock(&LOCK_grant);
  if (!show_tables)
  {
    const char *command="";
    if (want_access & SELECT_ACL)
       command ="select";
    else if (want_access & INSERT_ACL)
      command = "insert";
    else if (want_access & UPDATE_ACL)
      command = "update";
    my_printf_error(ER_COLUMNACCESS_DENIED_ERROR,
		    ER(ER_COLUMNACCESS_DENIED_ERROR),
		    MYF(0),
		    command,
		    thd->priv_user,
		    thd->host ? thd->host : (thd->ip ? thd->ip : "unknown"),
		    name,
		    table ? table->real_name : "unknown");
  }
  return 1;
}


bool check_grant_all_columns(THD *thd,uint want_access, TABLE *table)
{
  GRANT_TABLE *grant_table;
  GRANT_COLUMN *grant_column;
  Field *field=0,**ptr;

  want_access &= ~table->grant.privilege;
  if (!want_access)
    return 0;					// Already checked

  pthread_mutex_lock(&LOCK_grant);

  // reload table if someone has modified any grants

  if (table->grant.version != grant_version)
  {
    table->grant.grant_table=
      table_hash_search(thd->host,thd->ip,thd->db,
			thd->priv_user,
			table->real_name,0);	/* purecov: inspected */
    table->grant.version=grant_version;		/* purecov: inspected */
  }
  // The following should always be true
  if (!(grant_table=table->grant.grant_table))
    goto err;					/* purecov: inspected */

  for (ptr=table->field; (field= *ptr) ; ptr++)
  {
    grant_column=column_hash_search(grant_table, field->field_name,
				    (uint) strlen(field->field_name));
    if (!grant_column || (~grant_column->rights & want_access))
      goto err;
  }
  pthread_mutex_unlock(&LOCK_grant);
  return 0;

  /* We must use my_printf_error() here! */
 err:
  pthread_mutex_unlock(&LOCK_grant);

  const char *command="";
  if (want_access & SELECT_ACL)
    command ="select";
  else if (want_access & INSERT_ACL)
    command = "insert";
  my_printf_error(ER_COLUMNACCESS_DENIED_ERROR,
		  ER(ER_COLUMNACCESS_DENIED_ERROR),
		  MYF(0),
		  command,
		  thd->priv_user,
		  thd->host ? thd->host : (thd->ip ? thd->ip : "unknown"),
		  field ? field->field_name : "unknown",
		  table->real_name);
  return 1;
}


/****************************************************************************
** Check if a user has the right to access a database
** Access is accepted if he has a grant for any table in the database
** Return 1 if access is denied
****************************************************************************/

bool check_grant_db(THD *thd,const char *db)
{
  char helping [NAME_LEN+USERNAME_LENGTH+2];
  uint len;
  bool error=1;

  len  = (uint) (strmov(strmov(helping,thd->priv_user)+1,db)-helping)+ 1;
  pthread_mutex_lock(&LOCK_grant);

  for (uint idx=0 ; idx < hash_tables.records ; idx++)
  {
    GRANT_TABLE *grant_table = (GRANT_TABLE*) hash_element(&hash_tables,idx);
    if (len < grant_table->key_length &&
	!memcmp(grant_table->hash_key,helping,len) &&
	(thd->host && !wild_case_compare(thd->host,grant_table->host) ||
	 (thd->ip && !wild_case_compare(thd->ip,grant_table->host))))
    {
      error=0;					// Found match
      break;
    }
  }
  pthread_mutex_unlock(&LOCK_grant);
  return error;
}

/*****************************************************************************
** Functions to retrieve the grant for a table/column  (for SHOW functions)
*****************************************************************************/

uint get_table_grant(THD *thd, TABLE_LIST *table)
{
  char *user = thd->priv_user;
  const char *db = table->db ? table->db : thd->db;
  GRANT_TABLE *grant_table;

  pthread_mutex_lock(&LOCK_grant);
  grant_table = table_hash_search(thd->host,thd->ip,db,user,
				       table->real_name,0);
  table->grant.grant_table=grant_table; // Remember for column test
  table->grant.version=grant_version;
  if (grant_table)
    table->grant.privilege|= grant_table->privs;
  pthread_mutex_unlock(&LOCK_grant);
  return table->grant.privilege;
}


uint get_column_grant(THD *thd, TABLE_LIST *table, Field *field)
{
  GRANT_TABLE *grant_table;
  GRANT_COLUMN *grant_column;
  uint priv;

  pthread_mutex_lock(&LOCK_grant);
  // reload table if someone has modified any grants
  if (table->grant.version != grant_version)
  {
    table->grant.grant_table=
      table_hash_search(thd->host,thd->ip,thd->db,
			thd->priv_user,
			table->real_name,0);	/* purecov: inspected */
    table->grant.version=grant_version;		/* purecov: inspected */
  }

  if (!(grant_table=table->grant.grant_table))
    priv=table->grant.privilege;
  else
  {
    grant_column=column_hash_search(grant_table, field->field_name,
				    (uint) strlen(field->field_name));
    if (!grant_column)
      priv=table->grant.privilege;
    else
      priv=table->grant.privilege | grant_column->rights;
  }
  pthread_mutex_unlock(&LOCK_grant);
  return priv;
}


/*****************************************************************************
** SHOW GRANTS : send to client grant-like strings depicting user@host
** privileges
*****************************************************************************/

static const char *command_array[]=
{"SELECT", "INSERT","UPDATE","DELETE","CREATE", "DROP","RELOAD","SHUTDOWN",
 "PROCESS","FILE","GRANT","REFERENCES","INDEX","ALTER"};
static int command_lengths[]={6,6,6,6,6,4,6,8,7,4,5,9,5,5};

int mysql_show_grants(THD *thd,LEX_USER *lex_user) 
{
  uint counter, want_access,index;
  int  error = 0;
  ACL_USER *acl_user; ACL_DB *acl_db;
  char buff[1024];
  DBUG_ENTER("mysql_grant");

  LINT_INIT(acl_user);
  if (!initialized)
  {
    send_error(&(thd->net), ER_UNKNOWN_COM_ERROR);
    DBUG_RETURN(-1);
  }
  if (!lex_user->host.str)
  {
    lex_user->host.str=(char*) "%";
    lex_user->host.length=1;
  }
  if (lex_user->host.length > HOSTNAME_LENGTH ||
      lex_user->user.length > USERNAME_LENGTH)
  {
    my_error(ER_GRANT_WRONG_HOST_OR_USER,MYF(0));
    DBUG_RETURN(-1);
  }

  for (counter=0 ; counter < acl_users.elements ; counter++)
  {
    const char *user,*host;
    acl_user=dynamic_element(&acl_users,counter,ACL_USER*);
    if (!(user=acl_user->user))
      user="";
    if (!(host=acl_user->host.hostname))
      host="%";
    if (!strcmp(lex_user->user.str,user) &&
	!strcmp(lex_user->host.str,host))
      break;
  }
  if (counter == acl_users.elements) 
  {
    my_printf_error(ER_NONEXISTING_GRANT,ER(ER_NONEXISTING_GRANT),
		    MYF(0),lex_user->user.str,lex_user->host.str);
    DBUG_RETURN(-1);
  }

  Item_string *field=new Item_string("",0);
  List<Item> field_list;
  field->name=buff;
  field->max_length=1024;
  strxmov(buff,"Grants for ",lex_user->user.str,"@",
	  lex_user->host.str,NullS);
  field_list.push_back(field);
  if (send_fields(thd,field_list,1))
    DBUG_RETURN(-1);

  VOID(pthread_mutex_lock(&acl_cache->lock));

  /* Add first global access grants */
  if (acl_user->access || acl_user->password)
  {
    want_access=acl_user->access;
    String global(buff,sizeof(buff));
    global.length(0);
    global.append("GRANT ",6);

    if (test_all_bits(want_access, (GLOBAL_ACLS & ~ GRANT_ACL)))
      global.append("ALL PRIVILEGES",14);
    else if (!(want_access & ~GRANT_ACL))
      global.append("USAGE",5);
    else 
    {
      bool found=0;
      uint j,test_access= want_access & ~GRANT_ACL;
      for (counter=0, j = SELECT_ACL;j <= GLOBAL_ACLS;counter++,j <<= 1)
      {
	if (test_access & j) 
	{
	  if (found)
	    global.append(", ",2);
	  found=1;
	  global.append(command_array[counter],command_lengths[counter]);
	}
      }
    }
    global.append (" ON *.* TO '",12);
    global.append(lex_user->user.str,lex_user->user.length); 
    global.append ("'@'",3);
    global.append(lex_user->host.str,lex_user->host.length);
    global.append ('\'');
    if (acl_user->password)
    {
      char passd_buff[HASH_PASSWORD_LENGTH+1];
      make_password_from_salt(passd_buff,acl_user->salt);
      global.append(" IDENTIFIED BY PASSWORD '",25);
      global.append(passd_buff);
      global.append('\'');
    }
    if (want_access & GRANT_ACL)
      global.append(" WITH GRANT OPTION",18); 
    thd->packet.length(0);
    net_store_data(&thd->packet,global.ptr(),global.length());
    if (my_net_write(&thd->net,(char*) thd->packet.ptr(),
		     thd->packet.length()))
    {
      error=-1; goto end;
    }
  }

  /* Add database access */
  for (counter=0 ; counter < acl_dbs.elements ; counter++)
  {
    const char *user,*host;

    acl_db=dynamic_element(&acl_dbs,counter,ACL_DB*);
    if (!(user=acl_db->user))
      user="";
    if (!(host=acl_db->host.hostname))
      host="";

    if (!strcmp(lex_user->user.str,user) &&
	!strcmp(lex_user->host.str,host))
    {
      want_access=acl_db->access;
      if (want_access) 
      {
	String db(buff,sizeof(buff));
	db.length(0);
	db.append("GRANT ",6);

	if (test_all_bits(want_access,(DB_ACLS & ~GRANT_ACL)))
	  db.append("ALL PRIVILEGES",14);
	else
	{
	  int found=0, cnt;
	  uint j,test_access= want_access & ~GRANT_ACL;
	  for (cnt=0, j = SELECT_ACL; j <= DB_ACLS; cnt++,j <<= 1)
	  {
	    if (test_access & j)
	    {
	      if (found)
		db.append(", ",2);
	      found = 1;
	      db.append(command_array[cnt],command_lengths[cnt]);
	    }
	  }
	}
	db.append (" ON ",4);
	db.append(acl_db->db);
	db.append (".* TO '",7);
	db.append(lex_user->user.str,lex_user->user.length); 
	db.append ("'@'",3);
	db.append(lex_user->host.str, lex_user->host.length);
	db.append ('\'');	
	if (want_access & GRANT_ACL)
	  db.append(" WITH GRANT OPTION",18); 
	thd->packet.length(0);
	net_store_data(&thd->packet,db.ptr(),db.length());
	if (my_net_write(&thd->net,(char*) thd->packet.ptr(),
			 thd->packet.length()))
	{
	  error=-1;
	  goto end;
	}
      }
    }
  }

  /* Add column access */
  for (index=0 ; index < hash_tables.records ; index++)
  {
    const char *user,*host;
    GRANT_TABLE *grant_table= (GRANT_TABLE*) hash_element(&hash_tables,index); 

    if (!(user=grant_table->user))
      user="";
    if (!(host=grant_table->host))
      host="";

    if (!strcmp(lex_user->user.str,user) &&
	!strcmp(lex_user->host.str,host))
    {
      want_access=grant_table->privs;
      if ((want_access | grant_table->cols) != 0)
      {
	String global(buff,sizeof(buff));
	global.length(0);
	global.append("GRANT ",6);

	if (test_all_bits(grant_table->privs,(TABLE_ACLS & ~GRANT_ACL)))
	  global.append("ALL PRIVILEGES",14);
	else 
	{
	  int found=0;
	  uint j,test_access= (want_access | grant_table->cols) & ~GRANT_ACL;

	  for (counter=0, j = SELECT_ACL;j <= TABLE_ACLS; counter++,j <<= 1)
	  {
	    if (test_access & j) 
	    {
	      if (found)
		global.append(", ",2);
	      found = 1;
	      global.append(command_array[counter],command_lengths[counter]);

	      if (grant_table->cols) 
	      {
		uint found_col=0;
		for (uint col_index=0 ;
		     col_index < grant_table->hash_columns.records ;
		     col_index++)
		{
		  GRANT_COLUMN *grant_column = (GRANT_COLUMN*)
		    hash_element(&grant_table->hash_columns,col_index);
		  if (grant_column->rights & j) 
		  {
		    if (!found_col) 
		    {
		      global.append(" (",2);
		      found_col=1;
		    }
		    else
		      global.append(", ",2);
		    global.append(grant_column->column,
				  grant_column->key_length);
		  }
		}
		if (found_col)
		  global.append(')');
	      }
	    }
	  }
	}
	global.append(" ON ",4);
	global.append(grant_table->db);
	global.append(".",1);
	global.append(grant_table->tname);
	global.append(" TO '",5);
	global.append(lex_user->user.str,lex_user->user.length); 
	global.append("'@'",3);
	global.append(lex_user->host.str,lex_user->host.length); 
	global.append('\'');
	if (want_access & GRANT_ACL)
	  global.append(" WITH GRANT OPTION",18); 
	thd->packet.length(0);
	net_store_data(&thd->packet,global.ptr(),global.length());
	if (my_net_write(&thd->net,(char*) thd->packet.ptr(),
			 thd->packet.length()))
	{
	  error=-1;
	  goto end;
	}
      }
    }
  }
 end:
  VOID(pthread_mutex_unlock(&acl_cache->lock));
  send_eof(&thd->net);
  DBUG_RETURN(error);
}


/*****************************************************************************
** Instantiate used templates
*****************************************************************************/

#ifdef __GNUC__
template class List_iterator<LEX_COLUMN>;
template class List_iterator<LEX_USER>;
template class List<LEX_COLUMN>;
template class List<LEX_USER>;
#endif