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mariadb/sql/net_serv.cc
unknown 2a0d2fef51 Bug#12713 "Error in a stored function called from a SELECT doesn't 
cause ROLLBACK of statement", part 1. Review fixes.

Do not send OK/EOF packets to the client until we reached the end of 
the current statement.
This is a consolidation, to keep the functionality that is shared by all 
SQL statements in one place in the server.
Currently this functionality includes:
- close_thread_tables()
- log_slow_statement().

After this patch and the subsequent patch for Bug#12713, it shall also include:
- ha_autocommit_or_rollback()
- net_end_statement()
- query_cache_end_of_result().

In future it may also include:
- mysql_reset_thd_for_next_command().


include/mysql_com.h:
  Rename now unused members of NET: no_send_ok, no_send_error, report_error.
  These were server-specific variables related to the client/server
  protocol. They have been made obsolete by this patch.
  
  Previously the same members of NET were used to store the error message
  both on the client and on the server. 
  The error message was stored in net.last_error (client: mysql->net.last_error,
  server: thd->net.last_error).
  The error code was stored in net.last_errno (client: mysql->net.last_errno,
  server: thd->net.last_errno).
  The server error code and message are now stored elsewhere 
  (in the Diagnostics_area), thus NET members are no longer used by the
  server.
  Rename last_error to client_last_error, last_errno to client_last_errno
  to avoid potential bugs introduced by merges.
include/mysql_h.ic:
  Update the ABI file to reflect a rename. 
  Renames do not break the binary compatibility.
libmysql/libmysql.c:
  Rename last_error to client_last_error, last_errno to client_last_errno.
  This is necessary to ensure no unnoticed bugs introduced by merged
  changesets.
  
  Remove net.report_error, net.no_send_ok, net.no_send_error.
libmysql/manager.c:
  Rename net.last_errno to net.client_last_errno.
libmysqld/lib_sql.cc:
  Rename net.last_errno to net.client_last_errno.
  
  Update the embedded implementation of the client-server protocol to
  reflect the refactoring of protocol.cc.
libmysqld/libmysqld.c:
  Rename net.last_errno to net.client_last_errno.
mysql-test/r/events.result:
  Update to reflect the change in mysql_rm_db(). Now we drop stored
  routines and events for a given database name only if there
  is a directory for this database name. ha_drop_database() and
  query_cache_invalidate() are called likewise. 
  Previously we would attempt to drop routines/events even if database
  directory was not found (it worked, since routines and events are stored
  in tables). This fixes Bug 29958 "Weird message on DROP DATABASE if mysql.proc
  does not exist".
  The change was done because the previous code used to call send_ok()
  twice, which led to an assertion failure when asserts against it were
  added by this patch.
mysql-test/r/grant.result:
  Fix the patch for Bug 16470, now FLUSH PRIVILEGES produces an error 
  if mysql.procs_priv is missing.
  This fixes the assert that send_ok() must not called after send_error()
  (the original patch for Bug 16470 was prone to this).
mysql-test/suite/rpl/r/rpl_row_tabledefs_2myisam.result:
  Produce a more detailed error message.
mysql-test/suite/rpl/r/rpl_row_tabledefs_3innodb.result:
  Produce a more detailed error message.
mysql-test/t/grant.test:
  Update the test, now FLUSH PRIVILEGES returns an error if mysql.procs_priv
  is missing.
server-tools/instance-manager/mysql_connection.cc:
  Rename net.last_errno to net.client_last_errno.
sql/ha_ndbcluster_binlog.cc:
  Add asserts. 
  
  Use getters to access statement status information.
  
  Add a comment why run_query() is broken. Reset the diagnostics area
  in the end of run_query() to fulfill the invariant that the diagnostics_area
  is never assigned twice per statement (see the comment in the code
  when this can happen). We still do not clear thd->is_fatal_error and
  thd->is_slave_error, which may lead to bugs, I consider the whole affair
  as something to be dealt with separately.
sql/ha_partition.cc:
  fatal_error() doesn't set an error by itself. Perhaps we should
  remove this method altogether and instead add a flag to my_error 
  to set thd->is_fatal_error property.
  
  Meanwhile, this change is a part of inspection made to the entire source
  code with the goal to ensure that fatal_error()
  is always accompanied by my_error().
sql/item_func.cc:
  There is no net.last_error anymore. Remove the obsolete assignment.
sql/log_event.cc:
  Use getters to access statement error status information.
sql/log_event_old.cc:
  Use getters to access statement error status information.
sql/mysqld.cc:
  Previously, if a continue handler for an error was found, my_message_sql() 
  would not set an error in THD. Since the current statement
  must be aborted in any case, find_handler() had a hack to assign 
  thd->net.report_error to 1.
  
  Remove this hack. Set an error in my_message_sql() even if the continue
  handler is found. The error will be cleared anyway when the handler
  is executed. This is one action among many in this patch to ensure the 
  invariant that whenever thd->is_error() is TRUE, we have a message in 
  thd->main_da.message().
sql/net_serv.cc:
  Use a full-blown my_error() in net_serv.cc to report an error,
  instead of just setting net->last_errno. This ensures the invariant that
  whenever thd->is_error() returns TRUE, we have a message in 
  thd->main_da.message().
  
  Remove initialization of removed NET members.
sql/opt_range.cc:
  Use my_error() instead of just raising thd->net.report_error. 
  This ensures the invariant that whenever thd->is_error() returns TRUE, 
  there is a message in thd->main_da.message().
sql/opt_sum.cc:
  Move invocation of fatal_error() right next to the place where
  we set the error message. That makes it easier to track that whenever
  fatal_error() is called, there is a message in THD.
sql/protocol.cc:
  Rename send_ok() and send_eof() to net_send_ok() and net_send_eof() 
  respectively. These functions write directly to the network and are not 
  for use anywhere outside the client/server protocol code. 
  
  Remove the code that was responsible for cases when either there is 
  no error code, or no error message, or both.
  Instead the calling code ensures that they are always present. Asserts
  are added to enforce the invariant.
  
  Instead of a direct access to thd->server_status and thd->total_warn_count
  use function parameters, since these from now on don't always come directly
  from THD.
  
  Introduce net_end_statement(), the single-entry-point replacement API for 
  send_ok(), send_eof() and net_send_error().
  
  Implement Protocol::end_partial_result_set to use in select_send::abort()
  when there is a continue handler.
sql/protocol.h:
  Update declarations.
sql/repl_failsafe.cc:
  Use getters to access statement status information in THD.
  Rename net.last_error to net.client_last_error.
sql/rpl_record.cc:
  Set an error message in prepare_record() if there is no default
  value for the field -- later we do print this message to the client.
sql/rpl_rli.cc:
  Use getters to access statement status information in THD.
sql/slave.cc:
  In create_table_from_dump() (a common function that is used in 
  LOAD MASTER TABLE SQL statement and COM_LOAD_MASTER_DATA), instead of hacks
  with no_send_ok, clear the diagnostics area when mysql_rm_table() succeeded.
  
  Update has_temporary_error() to work correctly when no error is set.
  This is the case when Incident_log_event is executed: it always returns
  an error but does not set an error message.
  
  Use getters to access error status information.
sql/sp_head.cc:
  Instead of hacks with no_send_error, work through the diagnostics area 
  interface to suppress sending of OK/ERROR packets to the client.
  
  Move query_cache_end_of_result before log_slow_statement(), similarly
  to how it's done in dispatch_command().
sql/sp_rcontext.cc:
  Remove hacks with assignment of thd->net.report_error, they are not
  necessary any more (see the changes in mysqld.cc).
sql/sql_acl.cc:
  Use getters to access error status information in THD.
sql/sql_base.cc:
  Access thd->main_da.sql_errno() only if there is an error. This fixes
  a bug when auto-discovery, that was effectively disabled under pre-locking.
sql/sql_binlog.cc:
  Remove hacks with no_send_ok/no_send_error, they are not necessary 
  anymore: the caller is responsible for network communication.
sql/sql_cache.cc:
  Disable sending of OK/ERROR/EOF packet in the end of dispatch_command
  if the response has been served from the query cache. This raises the 
  question whether we should store EOF packet in the query cache at all,
  or generate it anew for each statement (we should generate it anew), but
  this is to be addressed separately.
sql/sql_class.cc:
  Implement class Diagnostics_area. Please see comments in sql_class.h
  for details.
  
  Fix a subtle coding mistake in select_send::send_data: when on slave, 
  an error in Item::send() was ignored.
  The problem became visible due to asserts that the diagnostics area is
  never double assigned.
  
  Remove initialization of removed NET members.
  
  In select_send::abort() do not call select_send::send_eof(). This is
  not inheritance-safe. Even if a stored procedure continue handler is
  found, the current statement is aborted, not succeeded.
  Instead introduce a Protocol API to send the required response, 
  Protocol::end_partial_result_set().
  
  This simplifies implementation of select_send::send_eof(). No need
  to add more asserts that there is no error, there is an assert inside
  Diagnostics_area::set_ok_status() already.
  
  Leave no trace of no_send_* in the code.
sql/sql_class.h:
  Declare class Diagnostics_area. 
  
  Remove the hack with no_send_ok from
  Substatement_state.
  
  Provide inline implementations of send_ok/send_eof.
  
  Add commetns.
sql/sql_connect.cc:
  Remove hacks with no_send_error. 
  
  Since now an error in THD is always set if net->error, it's not necessary
  to check both net->error and thd->is_error() in the do_command loop.
  
  Use thd->main_da.message() instead of net->last_errno.
  
  Remove the hack with is_slave_error in sys_init_connect. Since now we do not
  reset the diagnostics area in net_send_error (it's reset at the beginning
  of the next statement), we can access it safely even after 
  execute_init_command.
sql/sql_db.cc:
  Update the code to satisfy the invariant that the diagnostics area is never
  assigned twice.
  Incidentally, this fixes Bug 29958 "Weird message on DROP DATABASE if 
  mysql.proc does not exist".
sql/sql_delete.cc:
  Change multi-delete to abort in abort(), as per select_send protocol.
  Fixes the merge error with the test for Bug 29136
sql/sql_derived.cc:
  Use getters to access error information.
sql/sql_insert.cc:
  Use getters to access error information.
sql-common/client.c:
  Rename last_error to client_last_error, last_errno to client_last_errno.
sql/sql_parse.cc:
  Remove hacks with no_send_error. Deploy net_end_statement().
  
  The story of COM_SHUTDOWN is interesting. Long story short, the server 
  would become on its death's door, and only no_send_ok/no_send_error assigned
  by send_ok()/net_send_error() would hide its babbling from the client.
  
  First of all, COM_QUIT does not require a response. So, the comment saying
  "Let's send a response to possible COM_QUIT" is not only groundless 
  (even mysqladmin shutdown/mysql_shutdown() doesn't send COM_QUIT after 
  COM_SHUTDOWN), it's plainly incorrect.
  
  Secondly, besides this additional 'OK' packet to respond to a hypothetical
  COM_QUIT, there was the following code in dispatch_command():
  
  if (thd->killed)
    thd->send_kill_message();
  if (thd->is_error()
    net_send_error(thd);
  
  This worked out really funny for the thread through which COM_SHUTDOWN
  was delivered: we would get COM_SHUTDOWN, say okay, say okay again, 
  kill everybody, get the kill signal ourselves, and then attempt to say 
  "Server shutdown in progress" to the client that is very likely long gone.
  
  This all became visible when asserts were added that the Diagnostics_area
  is not assigned twice.
  
  Move query_cache_end_of_result() to the end of dispatch_command(), since
  net_send_eof() has been moved there. This is safe, query_cache_end_of_result()
  is a no-op if there is no started query in the cache.
  
  Consistently use select_send interface to call abort() or send_eof()
  depending on the operation result.
  
  Remove thd->fatal_error() from reset_master(), it was a no-op. 
  in hacks with no_send_error woudl save us
  from complete breakage of the client/server protocol.
  
  Consistently use select_send::abort() whenever there is an error, 
  and select_send::send_eof() in case of success.
  The issue became visible due to added asserts.
sql/sql_partition.cc:
  Always set an error in THD whenever there is a call to fatal_error().
sql/sql_prepare.cc:
  Deploy class Diagnostics_area.
  Remove the unnecessary juggling with the protocol in 
  Select_fetch_protocol_binary::send_eof(). EOF packet format is 
  protocol-independent.
sql/sql_select.cc:
  Call fatal_error() directly in opt_sum_query.
  Call my_error() whenever we call thd->fatal_error().
sql/sql_servers.cc:
  Use getters to access error information in THD.
sql/sql_show.cc:
  Use getters to access error information in THD.
  
  Add comments.
  
  Call my_error() whenever we call fatal_error().
sql/sql_table.cc:
  Replace hacks with no_send_ok with the interface of the diagnostics area.
  
  Clear the error if ENOENT error in ha_delete_table().
sql/sql_update.cc:
  Introduce multi_update::abort(), which is the proper way to abort a
  multi-update. This fixes the merge conflict between this patch and
  the patch for Bug 29136.
sql/table.cc:
  Use a getter to access error information in THD.
sql/tztime.cc:
  Use a getter to access error information in THD.
2007-12-12 18:21:01 +03:00

1149 lines
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/* Copyright (C) 2000 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 */
/*
This file is the net layer API for the MySQL client/server protocol,
which is a tightly coupled, proprietary protocol owned by MySQL AB.
Any re-implementations of this protocol must also be under GPL
unless one has got an license from MySQL AB stating otherwise.
*/
/*
Write and read of logical packets to/from socket
Writes are cached into net_buffer_length big packets.
Read packets are reallocated dynamicly when reading big packets.
Each logical packet has the following pre-info:
3 byte length & 1 byte package-number.
This file needs to be written in C as it's used by the libmysql client as a
C file.
*/
/*
HFTODO this must be hidden if we don't want client capabilities in
embedded library
*/
#include <my_global.h>
#include <mysql.h>
#include <mysql_embed.h>
#include <mysql_com.h>
#include <mysqld_error.h>
#include <my_sys.h>
#include <m_string.h>
#include <my_net.h>
#include <violite.h>
#include <signal.h>
#include <errno.h>
#ifdef __NETWARE__
#include <sys/select.h>
#endif
#ifdef EMBEDDED_LIBRARY
#undef MYSQL_SERVER
#undef MYSQL_CLIENT
#define MYSQL_CLIENT
#endif /*EMBEDDED_LIBRARY */
/*
The following handles the differences when this is linked between the
client and the server.
This gives an error if a too big packet is found
The server can change this with the -O switch, but because the client
can't normally do this the client should have a bigger max_allowed_packet.
*/
#if defined(__WIN__) || !defined(MYSQL_SERVER)
/* The following is because alarms doesn't work on windows. */
#define NO_ALARM
#endif
#ifndef NO_ALARM
#include "my_pthread.h"
void sql_print_error(const char *format,...);
#else
#define DONT_USE_THR_ALARM
#endif /* NO_ALARM */
#include "thr_alarm.h"
#ifdef MYSQL_SERVER
/*
The following variables/functions should really not be declared
extern, but as it's hard to include mysql_priv.h here, we have to
live with this for a while.
*/
extern uint test_flags;
extern ulong bytes_sent, bytes_received, net_big_packet_count;
extern pthread_mutex_t LOCK_bytes_sent , LOCK_bytes_received;
#ifndef MYSQL_INSTANCE_MANAGER
#ifdef HAVE_QUERY_CACHE
#define USE_QUERY_CACHE
extern void query_cache_init_query(NET *net);
extern void query_cache_insert(NET *net, const char *packet, ulong length);
#endif // HAVE_QUERY_CACHE
#define update_statistics(A) A
#endif /* MYSQL_INSTANCE_MANGER */
#endif /* defined(MYSQL_SERVER) && !defined(MYSQL_INSTANCE_MANAGER) */
#if !defined(MYSQL_SERVER) || defined(MYSQL_INSTANCE_MANAGER)
#define update_statistics(A)
#define thd_increment_bytes_sent(N)
#endif
#define TEST_BLOCKING 8
#define MAX_PACKET_LENGTH (256L*256L*256L-1)
static my_bool net_write_buff(NET *net,const uchar *packet,ulong len);
/* Init with packet info */
my_bool my_net_init(NET *net, Vio* vio)
{
DBUG_ENTER("my_net_init");
net->vio = vio;
my_net_local_init(net); /* Set some limits */
if (!(net->buff=(uchar*) my_malloc((size_t) net->max_packet+
NET_HEADER_SIZE + COMP_HEADER_SIZE,
MYF(MY_WME))))
DBUG_RETURN(1);
net->buff_end=net->buff+net->max_packet;
net->error=0; net->return_errno=0; net->return_status=0;
net->pkt_nr=net->compress_pkt_nr=0;
net->write_pos=net->read_pos = net->buff;
net->client_last_error[0]=0;
net->compress=0; net->reading_or_writing=0;
net->where_b = net->remain_in_buf=0;
net->client_last_errno=0;
#ifdef USE_QUERY_CACHE
query_cache_init_query(net);
#else
net->query_cache_query= 0;
#endif
if (vio != 0) /* If real connection */
{
net->fd = vio_fd(vio); /* For perl DBI/DBD */
#if defined(MYSQL_SERVER) && !defined(__WIN__)
if (!(test_flags & TEST_BLOCKING))
{
my_bool old_mode;
vio_blocking(vio, FALSE, &old_mode);
}
#endif
vio_fastsend(vio);
}
DBUG_RETURN(0);
}
void net_end(NET *net)
{
DBUG_ENTER("net_end");
my_free(net->buff,MYF(MY_ALLOW_ZERO_PTR));
net->buff=0;
DBUG_VOID_RETURN;
}
/* Realloc the packet buffer */
my_bool net_realloc(NET *net, size_t length)
{
uchar *buff;
size_t pkt_length;
DBUG_ENTER("net_realloc");
DBUG_PRINT("enter",("length: %lu", (ulong) length));
if (length >= net->max_packet_size)
{
DBUG_PRINT("error", ("Packet too large. Max size: %lu",
net->max_packet_size));
/* @todo: 1 and 2 codes are identical. */
net->error= 1;
net->client_last_errno= ER_NET_PACKET_TOO_LARGE;
#ifdef MYSQL_SERVER
my_error(ER_NET_PACKET_TOO_LARGE, MYF(0));
#endif
DBUG_RETURN(1);
}
pkt_length = (length+IO_SIZE-1) & ~(IO_SIZE-1);
/*
We must allocate some extra bytes for the end 0 and to be able to
read big compressed blocks
*/
if (!(buff= (uchar*) my_realloc((char*) net->buff, pkt_length +
NET_HEADER_SIZE + COMP_HEADER_SIZE,
MYF(MY_WME))))
{
/* @todo: 1 and 2 codes are identical. */
net->error= 1;
net->client_last_errno= ER_OUT_OF_RESOURCES;
/* In the server the error is reported by MY_WME flag. */
DBUG_RETURN(1);
}
net->buff=net->write_pos=buff;
net->buff_end=buff+(net->max_packet= (ulong) pkt_length);
DBUG_RETURN(0);
}
/*
Check if there is any data to be read from the socket
SYNOPSIS
net_data_is_ready()
sd socket descriptor
DESCRIPTION
Check if there is any data to be read from the socket.
RETURN VALUES
0 No data to read
1 Data or EOF to read
-1 Don't know if data is ready or not
*/
#if !defined(EMBEDDED_LIBRARY)
static int net_data_is_ready(my_socket sd)
{
#ifdef HAVE_POLL
struct pollfd ufds;
int res;
ufds.fd= sd;
ufds.events= POLLIN | POLLPRI;
if (!(res= poll(&ufds, 1, 0)))
return 0;
if (res < 0 || !(ufds.revents & (POLLIN | POLLPRI)))
return 0;
return 1;
#else
fd_set sfds;
struct timeval tv;
int res;
#ifndef __WIN__
/* Windows uses an _array_ of 64 fd's as default, so it's safe */
if (sd >= FD_SETSIZE)
return -1;
#define NET_DATA_IS_READY_CAN_RETURN_MINUS_ONE
#endif
FD_ZERO(&sfds);
FD_SET(sd, &sfds);
tv.tv_sec= tv.tv_usec= 0;
if ((res= select(sd+1, &sfds, NULL, NULL, &tv)) < 0)
return 0;
else
return test(res ? FD_ISSET(sd, &sfds) : 0);
#endif /* HAVE_POLL */
}
#endif /* EMBEDDED_LIBRARY */
/*
Remove unwanted characters from connection
and check if disconnected
SYNOPSIS
net_clear()
net NET handler
clear_buffer If <> 0, then clear all data from communication buffer
DESCRIPTION
Read from socket until there is nothing more to read. Discard
what is read.
If there is anything when to read 'net_clear' is called this
normally indicates an error in the protocol.
When connection is properly closed (for TCP it means with
a FIN packet), then select() considers a socket "ready to read",
in the sense that there's EOF to read, but read() returns 0.
*/
void net_clear(NET *net, my_bool clear_buffer)
{
#if !defined(EMBEDDED_LIBRARY)
size_t count;
int ready;
#endif
DBUG_ENTER("net_clear");
#if !defined(EMBEDDED_LIBRARY)
if (clear_buffer)
{
while ((ready= net_data_is_ready(net->vio->sd)) > 0)
{
/* The socket is ready */
if ((long) (count= vio_read(net->vio, net->buff,
(size_t) net->max_packet)) > 0)
{
DBUG_PRINT("info",("skipped %ld bytes from file: %s",
(long) count, vio_description(net->vio)));
#if defined(EXTRA_DEBUG)
fprintf(stderr,"Note: net_clear() skipped %ld bytes from file: %s\n",
(long) count, vio_description(net->vio));
#endif
}
else
{
DBUG_PRINT("info",("socket ready but only EOF to read - disconnected"));
net->error= 2;
break;
}
}
#ifdef NET_DATA_IS_READY_CAN_RETURN_MINUS_ONE
/* 'net_data_is_ready' returned "don't know" */
if (ready == -1)
{
/* Read unblocking to clear net */
my_bool old_mode;
if (!vio_blocking(net->vio, FALSE, &old_mode))
{
while ((long) (count= vio_read(net->vio, net->buff,
(size_t) net->max_packet)) > 0)
DBUG_PRINT("info",("skipped %ld bytes from file: %s",
(long) count, vio_description(net->vio)));
vio_blocking(net->vio, TRUE, &old_mode);
}
}
#endif /* NET_DATA_IS_READY_CAN_RETURN_MINUS_ONE */
}
#endif /* EMBEDDED_LIBRARY */
net->pkt_nr=net->compress_pkt_nr=0; /* Ready for new command */
net->write_pos=net->buff;
DBUG_VOID_RETURN;
}
/* Flush write_buffer if not empty. */
my_bool net_flush(NET *net)
{
my_bool error= 0;
DBUG_ENTER("net_flush");
if (net->buff != net->write_pos)
{
error=test(net_real_write(net, net->buff,
(size_t) (net->write_pos - net->buff)));
net->write_pos=net->buff;
}
/* Sync packet number if using compression */
if (net->compress)
net->pkt_nr=net->compress_pkt_nr;
DBUG_RETURN(error);
}
/*****************************************************************************
** Write something to server/client buffer
*****************************************************************************/
/*
Write a logical packet with packet header
Format: Packet length (3 bytes), packet number(1 byte)
When compression is used a 3 byte compression length is added
NOTE
If compression is used the original package is modified!
*/
my_bool
my_net_write(NET *net,const uchar *packet,size_t len)
{
uchar buff[NET_HEADER_SIZE];
if (unlikely(!net->vio)) /* nowhere to write */
return 0;
/*
Big packets are handled by splitting them in packets of MAX_PACKET_LENGTH
length. The last packet is always a packet that is < MAX_PACKET_LENGTH.
(The last packet may even have a length of 0)
*/
while (len >= MAX_PACKET_LENGTH)
{
const ulong z_size = MAX_PACKET_LENGTH;
int3store(buff, z_size);
buff[3]= (uchar) net->pkt_nr++;
if (net_write_buff(net, buff, NET_HEADER_SIZE) ||
net_write_buff(net, packet, z_size))
return 1;
packet += z_size;
len-= z_size;
}
/* Write last packet */
int3store(buff,len);
buff[3]= (uchar) net->pkt_nr++;
if (net_write_buff(net, buff, NET_HEADER_SIZE))
return 1;
#ifndef DEBUG_DATA_PACKETS
DBUG_DUMP("packet_header", buff, NET_HEADER_SIZE);
#endif
return test(net_write_buff(net,packet,len));
}
/*
Send a command to the server.
SYNOPSIS
net_write_command()
net NET handler
command Command in MySQL server (enum enum_server_command)
header Header to write after command
head_len Length of header
packet Query or parameter to query
len Length of packet
DESCRIPTION
The reason for having both header and packet is so that libmysql
can easy add a header to a special command (like prepared statements)
without having to re-alloc the string.
As the command is part of the first data packet, we have to do some data
juggling to put the command in there, without having to create a new
packet.
This function will split big packets into sub-packets if needed.
(Each sub packet can only be 2^24 bytes)
RETURN VALUES
0 ok
1 error
*/
my_bool
net_write_command(NET *net,uchar command,
const uchar *header, size_t head_len,
const uchar *packet, size_t len)
{
ulong length=len+1+head_len; /* 1 extra byte for command */
uchar buff[NET_HEADER_SIZE+1];
uint header_size=NET_HEADER_SIZE+1;
DBUG_ENTER("net_write_command");
DBUG_PRINT("enter",("length: %lu", (ulong) len));
buff[4]=command; /* For first packet */
if (length >= MAX_PACKET_LENGTH)
{
/* Take into account that we have the command in the first header */
len= MAX_PACKET_LENGTH - 1 - head_len;
do
{
int3store(buff, MAX_PACKET_LENGTH);
buff[3]= (uchar) net->pkt_nr++;
if (net_write_buff(net, buff, header_size) ||
net_write_buff(net, header, head_len) ||
net_write_buff(net, packet, len))
DBUG_RETURN(1);
packet+= len;
length-= MAX_PACKET_LENGTH;
len= MAX_PACKET_LENGTH;
head_len= 0;
header_size= NET_HEADER_SIZE;
} while (length >= MAX_PACKET_LENGTH);
len=length; /* Data left to be written */
}
int3store(buff,length);
buff[3]= (uchar) net->pkt_nr++;
DBUG_RETURN(test(net_write_buff(net, buff, header_size) ||
(head_len && net_write_buff(net, header, head_len)) ||
net_write_buff(net, packet, len) || net_flush(net)));
}
/*
Caching the data in a local buffer before sending it.
SYNOPSIS
net_write_buff()
net Network handler
packet Packet to send
len Length of packet
DESCRIPTION
Fill up net->buffer and send it to the client when full.
If the rest of the to-be-sent-packet is bigger than buffer,
send it in one big block (to avoid copying to internal buffer).
If not, copy the rest of the data to the buffer and return without
sending data.
NOTES
The cached buffer can be sent as it is with 'net_flush()'.
In this code we have to be careful to not send a packet longer than
MAX_PACKET_LENGTH to net_real_write() if we are using the compressed
protocol as we store the length of the compressed packet in 3 bytes.
RETURN
0 ok
1
*/
static my_bool
net_write_buff(NET *net, const uchar *packet, ulong len)
{
ulong left_length;
if (net->compress && net->max_packet > MAX_PACKET_LENGTH)
left_length= MAX_PACKET_LENGTH - (net->write_pos - net->buff);
else
left_length= (ulong) (net->buff_end - net->write_pos);
#ifdef DEBUG_DATA_PACKETS
DBUG_DUMP("data", packet, len);
#endif
if (len > left_length)
{
if (net->write_pos != net->buff)
{
/* Fill up already used packet and write it */
memcpy((char*) net->write_pos,packet,left_length);
if (net_real_write(net, net->buff,
(size_t) (net->write_pos - net->buff) + left_length))
return 1;
net->write_pos= net->buff;
packet+= left_length;
len-= left_length;
}
if (net->compress)
{
/*
We can't have bigger packets than 16M with compression
Because the uncompressed length is stored in 3 bytes
*/
left_length= MAX_PACKET_LENGTH;
while (len > left_length)
{
if (net_real_write(net, packet, left_length))
return 1;
packet+= left_length;
len-= left_length;
}
}
if (len > net->max_packet)
return net_real_write(net, packet, len) ? 1 : 0;
/* Send out rest of the blocks as full sized blocks */
}
memcpy((char*) net->write_pos,packet,len);
net->write_pos+= len;
return 0;
}
/*
Read and write one packet using timeouts.
If needed, the packet is compressed before sending.
*/
int
net_real_write(NET *net,const uchar *packet, size_t len)
{
size_t length;
const uchar *pos,*end;
thr_alarm_t alarmed;
#ifndef NO_ALARM
ALARM alarm_buff;
#endif
uint retry_count=0;
my_bool net_blocking = vio_is_blocking(net->vio);
DBUG_ENTER("net_real_write");
#if defined(MYSQL_SERVER) && defined(USE_QUERY_CACHE)
query_cache_insert(net, (char*) packet, len);
#endif
if (net->error == 2)
DBUG_RETURN(-1); /* socket can't be used */
net->reading_or_writing=2;
#ifdef HAVE_COMPRESS
if (net->compress)
{
size_t complen;
uchar *b;
uint header_length=NET_HEADER_SIZE+COMP_HEADER_SIZE;
if (!(b= (uchar*) my_malloc(len + NET_HEADER_SIZE +
COMP_HEADER_SIZE, MYF(MY_WME))))
{
net->error= 2;
net->client_last_errno= ER_OUT_OF_RESOURCES;
/* In the server, the error is reported by MY_WME flag. */
net->reading_or_writing= 0;
DBUG_RETURN(1);
}
memcpy(b+header_length,packet,len);
if (my_compress(b+header_length, &len, &complen))
complen=0;
int3store(&b[NET_HEADER_SIZE],complen);
int3store(b,len);
b[3]=(uchar) (net->compress_pkt_nr++);
len+= header_length;
packet= b;
}
#endif /* HAVE_COMPRESS */
#ifdef DEBUG_DATA_PACKETS
DBUG_DUMP("data", packet, len);
#endif
#ifndef NO_ALARM
thr_alarm_init(&alarmed);
if (net_blocking)
thr_alarm(&alarmed, net->write_timeout, &alarm_buff);
#else
alarmed=0;
/* Write timeout is set in my_net_set_write_timeout */
#endif /* NO_ALARM */
pos= packet;
end=pos+len;
while (pos != end)
{
if ((long) (length= vio_write(net->vio,pos,(size_t) (end-pos))) <= 0)
{
my_bool interrupted = vio_should_retry(net->vio);
#if !defined(__WIN__)
if ((interrupted || length == 0) && !thr_alarm_in_use(&alarmed))
{
if (!thr_alarm(&alarmed, net->write_timeout, &alarm_buff))
{ /* Always true for client */
my_bool old_mode;
while (vio_blocking(net->vio, TRUE, &old_mode) < 0)
{
if (vio_should_retry(net->vio) && retry_count++ < net->retry_count)
continue;
#ifdef EXTRA_DEBUG
fprintf(stderr,
"%s: my_net_write: fcntl returned error %d, aborting thread\n",
my_progname,vio_errno(net->vio));
#endif /* EXTRA_DEBUG */
net->error= 2; /* Close socket */
net->client_last_errno= ER_NET_PACKET_TOO_LARGE;
#ifdef MYSQL_SERVER
my_error(ER_NET_PACKET_TOO_LARGE, MYF(0));
#endif
goto end;
}
retry_count=0;
continue;
}
}
else
#endif /* !defined(__WIN__) */
if (thr_alarm_in_use(&alarmed) && !thr_got_alarm(&alarmed) &&
interrupted)
{
if (retry_count++ < net->retry_count)
continue;
#ifdef EXTRA_DEBUG
fprintf(stderr, "%s: write looped, aborting thread\n",
my_progname);
#endif /* EXTRA_DEBUG */
}
#if defined(THREAD_SAFE_CLIENT) && !defined(MYSQL_SERVER)
if (vio_errno(net->vio) == SOCKET_EINTR)
{
DBUG_PRINT("warning",("Interrupted write. Retrying..."));
continue;
}
#endif /* defined(THREAD_SAFE_CLIENT) && !defined(MYSQL_SERVER) */
net->error= 2; /* Close socket */
net->client_last_errno= (interrupted ? ER_NET_WRITE_INTERRUPTED :
ER_NET_ERROR_ON_WRITE);
#ifdef MYSQL_SERVER
my_error(net->client_last_errno, MYF(0));
#endif /* MYSQL_SERVER */
break;
}
pos+=length;
update_statistics(thd_increment_bytes_sent(length));
}
#ifndef __WIN__
end:
#endif
#ifdef HAVE_COMPRESS
if (net->compress)
my_free((char*) packet,MYF(0));
#endif
if (thr_alarm_in_use(&alarmed))
{
my_bool old_mode;
thr_end_alarm(&alarmed);
vio_blocking(net->vio, net_blocking, &old_mode);
}
net->reading_or_writing=0;
DBUG_RETURN(((int) (pos != end)));
}
/*****************************************************************************
** Read something from server/clinet
*****************************************************************************/
#ifndef NO_ALARM
static my_bool net_safe_read(NET *net, uchar *buff, size_t length,
thr_alarm_t *alarmed)
{
uint retry_count=0;
while (length > 0)
{
size_t tmp;
if ((long) (tmp= vio_read(net->vio, buff, length)) <= 0)
{
my_bool interrupted = vio_should_retry(net->vio);
if (!thr_got_alarm(alarmed) && interrupted)
{ /* Probably in MIT threads */
if (retry_count++ < net->retry_count)
continue;
}
return 1;
}
length-= tmp;
buff+= tmp;
}
return 0;
}
/*
Help function to clear the commuication buffer when we get a too big packet.
SYNOPSIS
my_net_skip_rest()
net Communication handle
remain Bytes to read
alarmed Parameter for thr_alarm()
alarm_buff Parameter for thr_alarm()
RETURN VALUES
0 Was able to read the whole packet
1 Got mailformed packet from client
*/
static my_bool my_net_skip_rest(NET *net, uint32 remain, thr_alarm_t *alarmed,
ALARM *alarm_buff)
{
uint32 old=remain;
DBUG_ENTER("my_net_skip_rest");
DBUG_PRINT("enter",("bytes_to_skip: %u", (uint) remain));
/* The following is good for debugging */
update_statistics(thd_increment_net_big_packet_count(1));
if (!thr_alarm_in_use(alarmed))
{
my_bool old_mode;
if (thr_alarm(alarmed,net->read_timeout, alarm_buff) ||
vio_blocking(net->vio, TRUE, &old_mode) < 0)
DBUG_RETURN(1); /* Can't setup, abort */
}
for (;;)
{
while (remain > 0)
{
size_t length= min(remain, net->max_packet);
if (net_safe_read(net, net->buff, length, alarmed))
DBUG_RETURN(1);
update_statistics(thd_increment_bytes_received(length));
remain -= (uint32) length;
}
if (old != MAX_PACKET_LENGTH)
break;
if (net_safe_read(net, net->buff, NET_HEADER_SIZE, alarmed))
DBUG_RETURN(1);
old=remain= uint3korr(net->buff);
net->pkt_nr++;
}
DBUG_RETURN(0);
}
#endif /* NO_ALARM */
/*
Reads one packet to net->buff + net->where_b
Returns length of packet. Long packets are handled by my_net_read().
This function reallocates the net->buff buffer if necessary.
*/
static ulong
my_real_read(NET *net, size_t *complen)
{
uchar *pos;
size_t length;
uint i,retry_count=0;
ulong len=packet_error;
thr_alarm_t alarmed;
#ifndef NO_ALARM
ALARM alarm_buff;
#endif
my_bool net_blocking=vio_is_blocking(net->vio);
uint32 remain= (net->compress ? NET_HEADER_SIZE+COMP_HEADER_SIZE :
NET_HEADER_SIZE);
*complen = 0;
net->reading_or_writing=1;
thr_alarm_init(&alarmed);
#ifndef NO_ALARM
if (net_blocking)
thr_alarm(&alarmed,net->read_timeout,&alarm_buff);
#else
/* Read timeout is set in my_net_set_read_timeout */
#endif /* NO_ALARM */
pos = net->buff + net->where_b; /* net->packet -4 */
for (i=0 ; i < 2 ; i++)
{
while (remain > 0)
{
/* First read is done with non blocking mode */
if ((long) (length= vio_read(net->vio, pos, remain)) <= 0L)
{
my_bool interrupted = vio_should_retry(net->vio);
DBUG_PRINT("info",("vio_read returned %ld errno: %d",
(long) length, vio_errno(net->vio)));
#if !defined(__WIN__) || defined(MYSQL_SERVER)
/*
We got an error that there was no data on the socket. We now set up
an alarm to not 'read forever', change the socket to non blocking
mode and try again
*/
if ((interrupted || length == 0) && !thr_alarm_in_use(&alarmed))
{
if (!thr_alarm(&alarmed,net->read_timeout,&alarm_buff)) /* Don't wait too long */
{
my_bool old_mode;
while (vio_blocking(net->vio, TRUE, &old_mode) < 0)
{
if (vio_should_retry(net->vio) &&
retry_count++ < net->retry_count)
continue;
DBUG_PRINT("error",
("fcntl returned error %d, aborting thread",
vio_errno(net->vio)));
#ifdef EXTRA_DEBUG
fprintf(stderr,
"%s: read: fcntl returned error %d, aborting thread\n",
my_progname,vio_errno(net->vio));
#endif /* EXTRA_DEBUG */
len= packet_error;
net->error= 2; /* Close socket */
net->client_last_errno= ER_NET_FCNTL_ERROR;
#ifdef MYSQL_SERVER
my_error(ER_NET_FCNTL_ERROR, MYF(0));
#endif
goto end;
}
retry_count=0;
continue;
}
}
#endif /* (!defined(__WIN__) || defined(MYSQL_SERVER) */
if (thr_alarm_in_use(&alarmed) && !thr_got_alarm(&alarmed) &&
interrupted)
{ /* Probably in MIT threads */
if (retry_count++ < net->retry_count)
continue;
#ifdef EXTRA_DEBUG
fprintf(stderr, "%s: read looped with error %d, aborting thread\n",
my_progname,vio_errno(net->vio));
#endif /* EXTRA_DEBUG */
}
#if defined(THREAD_SAFE_CLIENT) && !defined(MYSQL_SERVER)
if (vio_errno(net->vio) == SOCKET_EINTR)
{
DBUG_PRINT("warning",("Interrupted read. Retrying..."));
continue;
}
#endif
DBUG_PRINT("error",("Couldn't read packet: remain: %u errno: %d length: %ld",
remain, vio_errno(net->vio), (long) length));
len= packet_error;
net->error= 2; /* Close socket */
net->client_last_errno= (vio_was_interrupted(net->vio) ?
ER_NET_READ_INTERRUPTED :
ER_NET_READ_ERROR);
#ifdef MYSQL_SERVER
my_error(net->client_last_errno, MYF(0));
#endif
goto end;
}
remain -= (uint32) length;
pos+= length;
update_statistics(thd_increment_bytes_received(length));
}
if (i == 0)
{ /* First parts is packet length */
ulong helping;
DBUG_DUMP("packet_header", net->buff+net->where_b,
NET_HEADER_SIZE);
if (net->buff[net->where_b + 3] != (uchar) net->pkt_nr)
{
if (net->buff[net->where_b] != (uchar) 255)
{
DBUG_PRINT("error",
("Packets out of order (Found: %d, expected %u)",
(int) net->buff[net->where_b + 3],
net->pkt_nr));
#ifdef EXTRA_DEBUG
fflush(stdout);
fprintf(stderr,"Error: Packets out of order (Found: %d, expected %d)\n",
(int) net->buff[net->where_b + 3],
(uint) (uchar) net->pkt_nr);
fflush(stderr);
DBUG_ASSERT(0);
#endif
}
len= packet_error;
/* Not a NET error on the client. XXX: why? */
#ifdef MYSQL_SERVER
my_error(ER_NET_PACKETS_OUT_OF_ORDER, MYF(0));
#endif
goto end;
}
net->compress_pkt_nr= ++net->pkt_nr;
#ifdef HAVE_COMPRESS
if (net->compress)
{
/*
If the packet is compressed then complen > 0 and contains the
number of bytes in the uncompressed packet
*/
*complen=uint3korr(&(net->buff[net->where_b + NET_HEADER_SIZE]));
}
#endif
len=uint3korr(net->buff+net->where_b);
if (!len) /* End of big multi-packet */
goto end;
helping = max(len,*complen) + net->where_b;
/* The necessary size of net->buff */
if (helping >= net->max_packet)
{
if (net_realloc(net,helping))
{
#if defined(MYSQL_SERVER) && !defined(NO_ALARM)
if (!net->compress &&
!my_net_skip_rest(net, (uint32) len, &alarmed, &alarm_buff))
net->error= 3; /* Successfully skiped packet */
#endif
len= packet_error; /* Return error and close connection */
goto end;
}
}
pos=net->buff + net->where_b;
remain = (uint32) len;
}
}
end:
if (thr_alarm_in_use(&alarmed))
{
my_bool old_mode;
thr_end_alarm(&alarmed);
vio_blocking(net->vio, net_blocking, &old_mode);
}
net->reading_or_writing=0;
#ifdef DEBUG_DATA_PACKETS
if (len != packet_error)
DBUG_DUMP("data", net->buff+net->where_b, len);
#endif
return(len);
}
/*
Read a packet from the client/server and return it without the internal
package header.
If the packet is the first packet of a multi-packet packet
(which is indicated by the length of the packet = 0xffffff) then
all sub packets are read and concatenated.
If the packet was compressed, its uncompressed and the length of the
uncompressed packet is returned.
The function returns the length of the found packet or packet_error.
net->read_pos points to the read data.
*/
ulong
my_net_read(NET *net)
{
size_t len, complen;
#ifdef HAVE_COMPRESS
if (!net->compress)
{
#endif
len = my_real_read(net,&complen);
if (len == MAX_PACKET_LENGTH)
{
/* First packet of a multi-packet. Concatenate the packets */
ulong save_pos = net->where_b;
size_t total_length= 0;
do
{
net->where_b += len;
total_length += len;
len = my_real_read(net,&complen);
} while (len == MAX_PACKET_LENGTH);
if (len != packet_error)
len+= total_length;
net->where_b = save_pos;
}
net->read_pos = net->buff + net->where_b;
if (len != packet_error)
net->read_pos[len]=0; /* Safeguard for mysql_use_result */
return len;
#ifdef HAVE_COMPRESS
}
else
{
/* We are using the compressed protocol */
ulong buf_length;
ulong start_of_packet;
ulong first_packet_offset;
uint read_length, multi_byte_packet=0;
if (net->remain_in_buf)
{
buf_length= net->buf_length; /* Data left in old packet */
first_packet_offset= start_of_packet= (net->buf_length -
net->remain_in_buf);
/* Restore the character that was overwritten by the end 0 */
net->buff[start_of_packet]= net->save_char;
}
else
{
/* reuse buffer, as there is nothing in it that we need */
buf_length= start_of_packet= first_packet_offset= 0;
}
for (;;)
{
ulong packet_len;
if (buf_length - start_of_packet >= NET_HEADER_SIZE)
{
read_length = uint3korr(net->buff+start_of_packet);
if (!read_length)
{
/* End of multi-byte packet */
start_of_packet += NET_HEADER_SIZE;
break;
}
if (read_length + NET_HEADER_SIZE <= buf_length - start_of_packet)
{
if (multi_byte_packet)
{
/* Remove packet header for second packet */
memmove(net->buff + first_packet_offset + start_of_packet,
net->buff + first_packet_offset + start_of_packet +
NET_HEADER_SIZE,
buf_length - start_of_packet);
start_of_packet += read_length;
buf_length -= NET_HEADER_SIZE;
}
else
start_of_packet+= read_length + NET_HEADER_SIZE;
if (read_length != MAX_PACKET_LENGTH) /* last package */
{
multi_byte_packet= 0; /* No last zero len packet */
break;
}
multi_byte_packet= NET_HEADER_SIZE;
/* Move data down to read next data packet after current one */
if (first_packet_offset)
{
memmove(net->buff,net->buff+first_packet_offset,
buf_length-first_packet_offset);
buf_length-=first_packet_offset;
start_of_packet -= first_packet_offset;
first_packet_offset=0;
}
continue;
}
}
/* Move data down to read next data packet after current one */
if (first_packet_offset)
{
memmove(net->buff,net->buff+first_packet_offset,
buf_length-first_packet_offset);
buf_length-=first_packet_offset;
start_of_packet -= first_packet_offset;
first_packet_offset=0;
}
net->where_b=buf_length;
if ((packet_len = my_real_read(net,&complen)) == packet_error)
return packet_error;
if (my_uncompress(net->buff + net->where_b, packet_len,
&complen))
{
net->error= 2; /* caller will close socket */
net->client_last_errno= ER_NET_UNCOMPRESS_ERROR;
#ifdef MYSQL_SERVER
my_error(ER_NET_UNCOMPRESS_ERROR, MYF(0));
#endif
return packet_error;
}
buf_length+= complen;
}
net->read_pos= net->buff+ first_packet_offset + NET_HEADER_SIZE;
net->buf_length= buf_length;
net->remain_in_buf= (ulong) (buf_length - start_of_packet);
len = ((ulong) (start_of_packet - first_packet_offset) - NET_HEADER_SIZE -
multi_byte_packet);
net->save_char= net->read_pos[len]; /* Must be saved */
net->read_pos[len]=0; /* Safeguard for mysql_use_result */
}
#endif /* HAVE_COMPRESS */
return len;
}
void my_net_set_read_timeout(NET *net, uint timeout)
{
DBUG_ENTER("my_net_set_read_timeout");
DBUG_PRINT("enter", ("timeout: %d", timeout));
net->read_timeout= timeout;
#ifdef NO_ALARM
if (net->vio)
vio_timeout(net->vio, 0, timeout);
#endif
DBUG_VOID_RETURN;
}
void my_net_set_write_timeout(NET *net, uint timeout)
{
DBUG_ENTER("my_net_set_write_timeout");
DBUG_PRINT("enter", ("timeout: %d", timeout));
net->write_timeout= timeout;
#ifdef NO_ALARM
if (net->vio)
vio_timeout(net->vio, 1, timeout);
#endif
DBUG_VOID_RETURN;
}
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