~drizzle-trunk/drizzle/development

/* Copyright (C) 2007 MySQL 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; version 2 of the License.

   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 */

/*

  Functions to autenticate and handle reqests for a connection

*/

#include "mysql_priv.h"

#define MIN_HANDSHAKE_SIZE      6

/*

  Get structure for logging connection data for the current user

*/

char *ip_to_hostname(struct sockaddr_storage *in, int addrLen)

{

  char *name;

  int gxi_error;

  char hostname_buff[NI_MAXHOST];

  /* Historical comparison for 127.0.0.1 */

  gxi_error= getnameinfo((struct sockaddr *)in, addrLen,

                         hostname_buff, NI_MAXHOST,

                         NULL, 0, NI_NUMERICHOST);

  if (gxi_error)

  {

    return NULL;

  }

  if (!(name= my_strdup(hostname_buff, MYF(0))))

  {

    return NULL;

  }

  return NULL;

}

/**

  Check if user exist and password supplied is correct.

  @param  thd         thread handle, thd->security_ctx->{host,user,ip} are used

  @param  command     originator of the check: now check_user is called

                      during connect and change user procedures; used for

                      logging.

  @param  passwd      scrambled password received from client

  @param  passwd_len  length of scrambled password

  @param  db          database name to connect to, may be NULL

  @param  check_count true if establishing a new connection. In this case

                      check that we have not exceeded the global

                      max_connections limist

  @note Host, user and passwd may point to communication buffer.

  Current implementation does not depend on that, but future changes

  should be done with this in mind; 'thd' is INOUT, all other params

  are 'IN'.

  @retval  0  OK; thd->security_ctx->user/master_access/priv_user/db_access and

              thd->db are updated; OK is sent to the client.

  @retval  1  error, e.g. access denied or handshake error, not sent to

              the client. A message is pushed into the error stack.

*/

int

check_user(THD *thd, enum enum_server_command command,

           const char *passwd __attribute__((__unused__)),

           uint passwd_len, const char *db,

           bool check_count)

{

  LEX_STRING db_str= { (char *) db, db ? strlen(db) : 0 };

  /*

    Clear thd->db as it points to something, that will be freed when

    connection is closed. We don't want to accidentally free a wrong

    pointer if connect failed. Also in case of 'CHANGE USER' failure,

    current database will be switched to 'no database selected'.

  */

  thd->reset_db(NULL, 0);

  my_bool opt_secure_auth_local;

  pthread_mutex_lock(&LOCK_global_system_variables);

  opt_secure_auth_local= opt_secure_auth;

  pthread_mutex_unlock(&LOCK_global_system_variables);

  /*

    If the server is running in secure auth mode, short scrambles are 

    forbidden.

  */

  if (opt_secure_auth_local && passwd_len == SCRAMBLE_LENGTH_323)

  {

    my_error(ER_NOT_SUPPORTED_AUTH_MODE, MYF(0));

    general_log_print(thd, COM_CONNECT, ER(ER_NOT_SUPPORTED_AUTH_MODE));

    return(1);

  }

  if (passwd_len != 0 &&

      passwd_len != SCRAMBLE_LENGTH &&

      passwd_len != SCRAMBLE_LENGTH_323)

  {

    my_error(ER_HANDSHAKE_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);

    return(1);

  }

  USER_RESOURCES ur;

  thd->security_ctx->skip_grants();

  memset(&ur, 0, sizeof(USER_RESOURCES));

  if (check_count)

  {

    pthread_mutex_lock(&LOCK_connection_count);

    bool count_ok= connection_count <= max_connections;

    VOID(pthread_mutex_unlock(&LOCK_connection_count));

    if (!count_ok)

    {                                         // too many connections

      my_error(ER_CON_COUNT_ERROR, MYF(0));

      return(1);

    }

  }

  /*

    Log the command before authentication checks, so that the user can

    check the log for the tried login tried and also to detect

    break-in attempts.

  */

  general_log_print(thd, command,

                    (thd->main_security_ctx.priv_user ==

                     thd->main_security_ctx.user ?

                     (char*) "%s@%s on %s" :

                     (char*) "%s@%s as anonymous on %s"),

                    thd->main_security_ctx.user,

                    thd->main_security_ctx.host_or_ip,

                    db ? db : (char*) "");

  /*

    This is the default access rights for the current database.  It's

    set to 0 here because we don't have an active database yet (and we

    may not have an active database to set.

  */

  thd->main_security_ctx.db_access=0;

  /* Change database if necessary */

  if (db && db[0])

  {

    if (mysql_change_db(thd, &db_str, false))

    {

      /* mysql_change_db() has pushed the error message. */

      return(1);

    }

  }

  my_ok(thd);

  thd->password= test(passwd_len);          // remember for error messages 

  /* Ready to handle queries */

  return(0);

}

/*

  Check for maximum allowable user connections, if the mysqld server is

  started with corresponding variable that is greater then 0.

*/

extern "C" uchar *get_key_conn(user_conn *buff, size_t *length,

			      my_bool not_used __attribute__((unused)))

{

  *length= buff->len;

  return (uchar*) buff->user;

}

extern "C" void free_user(struct user_conn *uc)

{

  my_free((char*) uc,MYF(0));

}

void thd_init_client_charset(THD *thd, uint cs_number)

{

  /*

   Use server character set and collation if

   - opt_character_set_client_handshake is not set

   - client has not specified a character set

   - client character set is the same as the servers

   - client character set doesn't exists in server

  */

  if (!opt_character_set_client_handshake ||

      !(thd->variables.character_set_client= get_charset(cs_number, MYF(0))) ||

      !my_strcasecmp(&my_charset_latin1,

                     global_system_variables.character_set_client->name,

                     thd->variables.character_set_client->name))

  {

    thd->variables.character_set_client=

      global_system_variables.character_set_client;

    thd->variables.collation_connection=

      global_system_variables.collation_connection;

    thd->variables.character_set_results=

      global_system_variables.character_set_results;

  }

  else

  {

    thd->variables.character_set_results=

      thd->variables.collation_connection= 

      thd->variables.character_set_client;

  }

}

/*

  Initialize connection threads

*/

bool init_new_connection_handler_thread()

{

  pthread_detach_this_thread();

  /* Win32 calls this in pthread_create */

  if (my_thread_init())

    return 1;

  return 0;

}

/*

  Perform handshake, authorize client and update thd ACL variables.

  SYNOPSIS

    check_connection()

    thd  thread handle

  RETURN

     0  success, OK is sent to user, thd is updated.

    -1  error, which is sent to user

   > 0  error code (not sent to user)

*/

static int check_connection(THD *thd)

{

  NET *net= &thd->net;

  ulong pkt_len= 0;

  char *end;

#ifdef SIGNAL_WITH_VIO_CLOSE

  thd->set_active_vio(net->vio);

#endif

  if (!thd->main_security_ctx.host)         // If TCP/IP connection

  {

    char ip[NI_MAXHOST];

    if (vio_peer_addr(net->vio, ip, &thd->peer_port, NI_MAXHOST))

    {

      my_error(ER_BAD_HOST_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);

      return 1;

    }

    if (!(thd->main_security_ctx.ip= my_strdup(ip,MYF(MY_WME))))

      return 1; /* The error is set by my_strdup(). */

    thd->main_security_ctx.host_or_ip= thd->main_security_ctx.ip;

    thd->main_security_ctx.host= ip_to_hostname(&net->vio->remote, 

                                                net->vio->addrLen);

    thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;

  }

  else /* Hostname given means that the connection was on a socket */

  {

    thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;

    thd->main_security_ctx.ip= 0;

    /* Reset sin_addr */

    bzero((char*) &net->vio->remote, sizeof(net->vio->remote));

  }

  vio_keepalive(net->vio, true);

  ulong server_capabilites;

  {

    /* buff[] needs to big enough to hold the server_version variable */

    char buff[SERVER_VERSION_LENGTH + SCRAMBLE_LENGTH + 64];

    server_capabilites= CLIENT_BASIC_FLAGS;

    if (opt_using_transactions)

      server_capabilites|= CLIENT_TRANSACTIONS;

#ifdef HAVE_COMPRESS

    server_capabilites|= CLIENT_COMPRESS;

#endif /* HAVE_COMPRESS */

    end= strnmov(buff, server_version, SERVER_VERSION_LENGTH) + 1;

    int4store((uchar*) end, thd->thread_id);

    end+= 4;

    /*

      So as check_connection is the only entry point to authorization

      procedure, scramble is set here. This gives us new scramble for

      each handshake.

    */

    create_random_string(thd->scramble, SCRAMBLE_LENGTH, &thd->rand);

    /*

      Old clients does not understand long scrambles, but can ignore packet

      tail: that's why first part of the scramble is placed here, and second

      part at the end of packet.

    */

    end= strmake(end, thd->scramble, SCRAMBLE_LENGTH_323) + 1;

    int2store(end, server_capabilites);

    /* write server characteristics: up to 16 bytes allowed */

    end[2]=(char) default_charset_info->number;

    int2store(end+3, thd->server_status);

    bzero(end+5, 13);

    end+= 18;

    /* write scramble tail */

    end= strmake(end, thd->scramble + SCRAMBLE_LENGTH_323, 

                 SCRAMBLE_LENGTH - SCRAMBLE_LENGTH_323) + 1;

    /* At this point we write connection message and read reply */

    if (net_write_command(net, (uchar) protocol_version, (uchar*) "", 0,

                          (uchar*) buff, (size_t) (end-buff)) ||

	(pkt_len= my_net_read(net)) == packet_error ||

	pkt_len < MIN_HANDSHAKE_SIZE)

    {

      my_error(ER_HANDSHAKE_ERROR, MYF(0),

               thd->main_security_ctx.host_or_ip);

      return 1;

    }

  }

#ifdef _CUSTOMCONFIG_

#include "_cust_sql_parse.h"

#endif

  if (thd->packet.alloc(thd->variables.net_buffer_length))

    return 1; /* The error is set by alloc(). */

  thd->client_capabilities= uint2korr(net->read_pos);

  if (thd->client_capabilities & CLIENT_PROTOCOL_41)

  {

    thd->client_capabilities|= ((ulong) uint2korr(net->read_pos+2)) << 16;

    thd->max_client_packet_length= uint4korr(net->read_pos+4);

    thd_init_client_charset(thd, (uint) net->read_pos[8]);

    thd->update_charset();

    end= (char*) net->read_pos+32;

  }

  else

  {

    thd->max_client_packet_length= uint3korr(net->read_pos+2);

    end= (char*) net->read_pos+5;

  }

  /*

    Disable those bits which are not supported by the server.

    This is a precautionary measure, if the client lies. See Bug#27944.

  */

  thd->client_capabilities&= server_capabilites;

  if (thd->client_capabilities & CLIENT_IGNORE_SPACE)

    thd->variables.sql_mode|= MODE_IGNORE_SPACE;

  if (end >= (char*) net->read_pos+ pkt_len +2)

  {

    my_error(ER_HANDSHAKE_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);

    return 1;

  }

  if (thd->client_capabilities & CLIENT_INTERACTIVE)

    thd->variables.net_wait_timeout= thd->variables.net_interactive_timeout;

  if ((thd->client_capabilities & CLIENT_TRANSACTIONS) &&

      opt_using_transactions)

    net->return_status= &thd->server_status;

  char *user= end;

  char *passwd= strend(user)+1;

  uint user_len= passwd - user - 1;

  char *db= passwd;

  char db_buff[NAME_LEN + 1];           // buffer to store db in utf8

  char user_buff[USERNAME_LENGTH + 1];	// buffer to store user in utf8

  uint dummy_errors;

  /*

    Old clients send null-terminated string as password; new clients send

    the size (1 byte) + string (not null-terminated). Hence in case of empty

    password both send '\0'.

    This strlen() can't be easily deleted without changing protocol.

    Cast *passwd to an unsigned char, so that it doesn't extend the sign for

    *passwd > 127 and become 2**32-127+ after casting to uint.

  */

  uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ?

    (uchar)(*passwd++) : strlen(passwd);

  db= thd->client_capabilities & CLIENT_CONNECT_WITH_DB ?

    db + passwd_len + 1 : 0;

  /* strlen() can't be easily deleted without changing protocol */

  uint db_len= db ? strlen(db) : 0;

  if (passwd + passwd_len + db_len > (char *)net->read_pos + pkt_len)

  {

    my_error(ER_HANDSHAKE_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);

    return 1;

  }

  /* Since 4.1 all database names are stored in utf8 */

  if (db)

  {

    db_buff[copy_and_convert(db_buff, sizeof(db_buff)-1,

                             system_charset_info,

                             db, db_len,

                             thd->charset(), &dummy_errors)]= 0;

    db= db_buff;

  }

  user_buff[user_len= copy_and_convert(user_buff, sizeof(user_buff)-1,

                                       system_charset_info, user, user_len,

                                       thd->charset(), &dummy_errors)]= '\0';

  user= user_buff;

  /* If username starts and ends in "'", chop them off */

  if (user_len > 1 && user[0] == '\'' && user[user_len - 1] == '\'')

  {

    user[user_len-1]= 0;

    user++;

    user_len-= 2;

  }

  if (thd->main_security_ctx.user)

    x_free(thd->main_security_ctx.user);

  if (!(thd->main_security_ctx.user= my_strdup(user, MYF(MY_WME))))

    return 1; /* The error is set by my_strdup(). */

  return check_user(thd, COM_CONNECT, passwd, passwd_len, db, true);

}

/*

  Setup thread to be used with the current thread

  SYNOPSIS

    bool setup_connection_thread_globals()

    thd    Thread/connection handler

  RETURN

    0   ok

    1   Error (out of memory)

        In this case we will close the connection and increment status

*/

bool setup_connection_thread_globals(THD *thd)

{

  if (thd->store_globals())

  {

    close_connection(thd, ER_OUT_OF_RESOURCES, 1);

    statistic_increment(aborted_connects,&LOCK_status);

    thread_scheduler.end_thread(thd, 0);

    return 1;                                   // Error

  }

  return 0;

}

/*

  Autenticate user, with error reporting

  SYNOPSIS

   login_connection()

   thd        Thread handler

  NOTES

    Connection is not closed in case of errors

  RETURN

    0    ok

    1    error

*/

bool login_connection(THD *thd)

{

  NET *net= &thd->net;

  int error;

  /* Use "connect_timeout" value during connection phase */

  my_net_set_read_timeout(net, connect_timeout);

  my_net_set_write_timeout(net, connect_timeout);

  lex_start(thd);

  error= check_connection(thd);

  net_end_statement(thd);

  if (error)

  {						// Wrong permissions

    statistic_increment(aborted_connects,&LOCK_status);

    return(1);

  }

  /* Connect completed, set read/write timeouts back to default */

  my_net_set_read_timeout(net, thd->variables.net_read_timeout);

  my_net_set_write_timeout(net, thd->variables.net_write_timeout);

  return(0);

}

/*

  Close an established connection

  NOTES

    This mainly updates status variables

*/

void end_connection(THD *thd)

{

  NET *net= &thd->net;

  plugin_thdvar_cleanup(thd);

  if (thd->killed || (net->error && net->vio != 0))

  {

    statistic_increment(aborted_threads,&LOCK_status);

  }

  if (net->error && net->vio != 0)

  {

    if (!thd->killed && thd->variables.log_warnings > 1)

    {

      Security_context *sctx= thd->security_ctx;

      sql_print_warning(ER(ER_NEW_ABORTING_CONNECTION),

                        thd->thread_id,(thd->db ? thd->db : "unconnected"),

                        sctx->user ? sctx->user : "unauthenticated",

                        sctx->host_or_ip,

                        (thd->main_da.is_error() ? thd->main_da.message() :

                         ER(ER_UNKNOWN_ERROR)));

    }

  }

}

/*

  Initialize THD to handle queries

*/

void prepare_new_connection_state(THD* thd)

{

  Security_context *sctx= thd->security_ctx;

  if (thd->variables.max_join_size == HA_POS_ERROR)

    thd->options |= OPTION_BIG_SELECTS;

  if (thd->client_capabilities & CLIENT_COMPRESS)

    thd->net.compress=1;				// Use compression

  /*

    Much of this is duplicated in create_embedded_thd() for the

    embedded server library.

    TODO: refactor this to avoid code duplication there

  */

  thd->version= refresh_version;

  thd->proc_info= 0;

  thd->command= COM_SLEEP;

  thd->set_time();

  thd->init_for_queries();

  /* In the past this would only run of the user did not have SUPER_ACL */

  if (sys_init_connect.value_length)

  {

    execute_init_command(thd, &sys_init_connect, &LOCK_sys_init_connect);

    if (thd->is_error())

    {

      thd->killed= THD::KILL_CONNECTION;

      sql_print_warning(ER(ER_NEW_ABORTING_CONNECTION),

                        thd->thread_id,(thd->db ? thd->db : "unconnected"),

                        sctx->user ? sctx->user : "unauthenticated",

                        sctx->host_or_ip, "init_connect command failed");

      sql_print_warning("%s", thd->main_da.message());

    }

    thd->proc_info=0;

    thd->set_time();

    thd->init_for_queries();

  }

}

/*

  Thread handler for a connection

  SYNOPSIS

    handle_one_connection()

    arg		Connection object (THD)

  IMPLEMENTATION

    This function (normally) does the following:

    - Initialize thread

    - Initialize THD to be used with this thread

    - Authenticate user

    - Execute all queries sent on the connection

    - Take connection down

    - End thread  / Handle next connection using thread from thread cache

*/

pthread_handler_t handle_one_connection(void *arg)

{

  THD *thd= (THD*) arg;

  ulong launch_time= (ulong) ((thd->thr_create_utime= my_micro_time()) -

                              thd->connect_utime);

  if (thread_scheduler.init_new_connection_thread())

  {

    close_connection(thd, ER_OUT_OF_RESOURCES, 1);

    statistic_increment(aborted_connects,&LOCK_status);

    thread_scheduler.end_thread(thd,0);

    return 0;

  }

  if (launch_time >= slow_launch_time*1000000L)

    statistic_increment(slow_launch_threads,&LOCK_status);

  /*

    handle_one_connection() is normally the only way a thread would

    start and would always be on the very high end of the stack ,

    therefore, the thread stack always starts at the address of the

    first local variable of handle_one_connection, which is thd. We

    need to know the start of the stack so that we could check for

    stack overruns.

  */

  thd->thread_stack= (char*) &thd;

  if (setup_connection_thread_globals(thd))

    return 0;

  for (;;)

  {

    NET *net= &thd->net;

    if (login_connection(thd))

      goto end_thread;

    prepare_new_connection_state(thd);

    while (!net->error && net->vio != 0 &&

           !(thd->killed == THD::KILL_CONNECTION))

    {

      if (do_command(thd))

	break;

    }

    end_connection(thd);

end_thread:

    close_connection(thd, 0, 1);

    if (thread_scheduler.end_thread(thd,1))

      return 0;                                 // Probably no-threads

    /*

      If end_thread() returns, we are either running with

      thread-handler=no-threads or this thread has been schedule to

      handle the next connection.

    */

    thd= current_thd;

    thd->thread_stack= (char*) &thd;

  }

}