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Diffstat (limited to 'sql/net_serv.cc')
| -rw-r--r-- | sql/net_serv.cc | 1437 |
1 files changed, 1437 insertions, 0 deletions
diff --git a/sql/net_serv.cc b/sql/net_serv.cc new file mode 100644 index 00000000..1d2409f1 --- /dev/null +++ b/sql/net_serv.cc @@ -0,0 +1,1437 @@ +/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. + Copyright (c) 2012, 2020, MariaDB Corporation. + + 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */ + +/** + @file + + This file is the net layer API for the MySQL client/server protocol. + + 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 "mariadb.h" +#include <mysql.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 "probes_mysql.h" +#include <debug_sync.h> +#include "proxy_protocol.h" + +PSI_memory_key key_memory_NET_buff; +PSI_memory_key key_memory_NET_compress_packet; + +#ifdef EMBEDDED_LIBRARY +#undef MYSQL_SERVER +#undef MYSQL_CLIENT +#define MYSQL_CLIENT +#endif /*EMBEDDED_LIBRARY */ + +/* + to reduce the number of ifdef's in the code +*/ +#ifdef EXTRA_DEBUG +#define EXTRA_DEBUG_fprintf fprintf +#define EXTRA_DEBUG_fflush fflush +#define EXTRA_DEBUG_ASSERT DBUG_ASSERT +#else +static void inline EXTRA_DEBUG_fprintf(...) {} +#ifndef MYSQL_SERVER +static int inline EXTRA_DEBUG_fflush(...) { return 0; } +#endif +#endif /* EXTRA_DEBUG */ + +#ifdef MYSQL_SERVER +#include <sql_class.h> +#include <sql_connect.h> +#define MYSQL_SERVER_my_error my_error +#else +static void inline MYSQL_SERVER_my_error(...) {} +#endif + +#ifndef EXTRA_DEBUG_ASSERT +# define EXTRA_DEBUG_ASSERT(X) do {} while(0) +#endif + +/* + 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, 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. */ +#ifndef NO_ALARM +#define NO_ALARM +#endif +#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 sql_priv.h here, we have to + live with this for a while. +*/ +extern ulonglong test_flags; +extern ulong bytes_sent, bytes_received, net_big_packet_count; +#ifdef HAVE_QUERY_CACHE +#define USE_QUERY_CACHE +extern void query_cache_insert(void *thd, const char *packet, size_t length, + unsigned pkt_nr); +#endif // HAVE_QUERY_CACHE +#define update_statistics(A) A +extern my_bool thd_net_is_killed(THD *thd); +/* Additional instrumentation hooks for the server */ +#include "mysql_com_server.h" +#else +#define update_statistics(A) +#define thd_net_is_killed(A) 0 +#endif + + +static my_bool net_write_buff(NET *, const uchar *, size_t len); + +my_bool net_allocate_new_packet(NET *net, void *thd, uint my_flags); + +/** Init with packet info. */ + +my_bool my_net_init(NET *net, Vio *vio, void *thd, uint my_flags) +{ + DBUG_ENTER("my_net_init"); + DBUG_PRINT("enter", ("my_flags: %u", my_flags)); + net->vio = vio; + net->read_timeout= 0; + net->write_timeout= 0; + my_net_local_init(net); /* Set some limits */ + + if (net_allocate_new_packet(net, thd, my_flags)) + DBUG_RETURN(1); + + net->error=0; net->return_status=0; + net->pkt_nr=net->compress_pkt_nr=0; + net->last_error[0]=0; + net->compress=0; net->reading_or_writing=0; + net->where_b = net->remain_in_buf=0; + net->net_skip_rest_factor= 0; + net->last_errno=0; + net->thread_specific_malloc= MY_TEST(my_flags & MY_THREAD_SPECIFIC); + net->thd= 0; +#ifdef MYSQL_SERVER + net->extension= NULL; + net->thd= thd; +#endif + + if (vio) + { + /* For perl DBI/DBD. */ + net->fd= vio_fd(vio); +#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); +} + + +/** + Allocate and assign new net buffer + + @note In case of error the old buffer left + + @retval TRUE error + @retval FALSE success +*/ + +my_bool net_allocate_new_packet(NET *net, void *thd, uint my_flags) +{ + uchar *tmp; + DBUG_ENTER("net_allocate_new_packet"); + if (!(tmp= (uchar*) my_malloc(key_memory_NET_buff, + (size_t) net->max_packet + + NET_HEADER_SIZE + COMP_HEADER_SIZE + 1, + MYF(MY_WME | my_flags)))) + DBUG_RETURN(1); + net->buff= tmp; + net->buff_end=net->buff+net->max_packet; + net->write_pos=net->read_pos = net->buff; + DBUG_RETURN(0); +} + + +void net_end(NET *net) +{ + DBUG_ENTER("net_end"); + my_free(net->buff); + 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->last_errno= ER_NET_PACKET_TOO_LARGE; + MYSQL_SERVER_my_error(ER_NET_PACKET_TOO_LARGE, MYF(0)); + 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 + 1 safety byte since uint3korr() in + my_real_read() may actually read 4 bytes depending on build flags and + platform. + */ + if (!(buff= (uchar*) my_realloc(key_memory_NET_buff, + (char*) net->buff, pkt_length + + NET_HEADER_SIZE + COMP_HEADER_SIZE + 1, + MYF(MY_WME | (net->thread_specific_malloc + ? MY_THREAD_SPECIFIC : 0))))) + { + /* @todo: 1 and 2 codes are identical. */ + net->error= 1; + net->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. + + @param sd socket descriptor + + @retval + 0 No data to read + @retval + 1 Data or EOF to read + @retval + -1 Don't know if data is ready or not +*/ + +#if !defined(EMBEDDED_LIBRARY) && defined(DBUG_OFF) + +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((int) (sd + 1), &sfds, NULL, NULL, &tv)) < 0) + return 0; + else + return MY_TEST(res ? FD_ISSET(sd, &sfds) : 0); +#endif /* HAVE_POLL */ +} + +#endif /* EMBEDDED_LIBRARY */ + +/** + Clear (reinitialize) the NET structure for a new command. + + @remark Performs debug checking of the socket buffer to + ensure that the protocol sequence is correct. + + - Read from socket until there is nothing more to read. Discard + what is read. + - Initialize net for new net_read/net_write calls. + + If there is anything when to read 'net_clear' is called this + normally indicates an error in the protocol. Normally one should not + need to do clear the communication buffer. If one compiles without + -DUSE_NET_CLEAR then one wins one read call / query. + + 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. + + @param net NET handler + @param clear_buffer if <> 0, then clear all data from comm buff +*/ + +void net_clear(NET *net, my_bool clear_buffer __attribute__((unused))) +{ + DBUG_ENTER("net_clear"); + +/* + We don't do a clear in case of not DBUG_OFF to catch bugs in the + protocol handling. +*/ + +#if (!defined(EMBEDDED_LIBRARY) && defined(DBUG_OFF)) || defined(USE_NET_CLEAR) + if (clear_buffer) + { + size_t count; + int ready; + while ((ready= net_data_is_ready(vio_fd(net->vio))) > 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))); + EXTRA_DEBUG_fprintf(stderr,"Note: net_clear() skipped %ld bytes from file: %s\n", + (long) count, vio_description(net->vio)); + } + 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= MY_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 packet 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; + + MYSQL_NET_WRITE_START(len); + + /* + 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)) + { + MYSQL_NET_WRITE_DONE(1); + 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)) + { + MYSQL_NET_WRITE_DONE(1); + return 1; + } +#ifndef DEBUG_DATA_PACKETS + DBUG_DUMP("packet_header", buff, NET_HEADER_SIZE); +#endif + my_bool rc= MY_TEST(net_write_buff(net, packet, len)); + MYSQL_NET_WRITE_DONE(rc); + return rc; +} + + +/** + Send a command to the server. + + 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) + + @param net NET handler + @param command Command in MySQL server (enum enum_server_command) + @param header Header to write after command + @param head_len Length of header + @param packet Query or parameter to query + @param len Length of packet + + @retval + 0 ok + @retval + 1 error +*/ + +my_bool +net_write_command(NET *net,uchar command, + const uchar *header, size_t head_len, + const uchar *packet, size_t len) +{ + size_t length=len+1+head_len; /* 1 extra byte for command */ + uchar buff[NET_HEADER_SIZE+1]; + uint header_size=NET_HEADER_SIZE+1; + my_bool rc; + DBUG_ENTER("net_write_command"); + DBUG_PRINT("enter",("length: %lu", (ulong) len)); + + DBUG_EXECUTE_IF("simulate_error_on_packet_write", + { + if (command == COM_BINLOG_DUMP) + { + net->last_errno = ER_NET_ERROR_ON_WRITE; + DBUG_ASSERT(!debug_sync_set_action( + (THD *)net->thd, + STRING_WITH_LEN("now SIGNAL parked WAIT_FOR continue"))); + DBUG_RETURN(true); + } + };); + MYSQL_NET_WRITE_START(length); + + 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)) + { + MYSQL_NET_WRITE_DONE(1); + 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++; + rc= MY_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)); + MYSQL_NET_WRITE_DONE(rc); + DBUG_RETURN(rc); +} + +/** + Caching the data in a local buffer before sending it. + + 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. + + @param net Network handler + @param packet Packet to send + @param len Length of packet + + @note + 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. + + @retval + 0 ok + @retval + 1 +*/ + +static my_bool +net_write_buff(NET *net, const uchar *packet, size_t len) +{ + size_t left_length; + if (net->compress && net->max_packet > MAX_PACKET_LENGTH) + left_length= (MAX_PACKET_LENGTH - (net->write_pos - net->buff)); + else + left_length= (net->buff_end - net->write_pos); + +#ifdef DEBUG_DATA_PACKETS + DBUG_DUMP("data_written", 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 */ + } + if (len) + 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. + + @todo + - TODO is it needed to set this variable if we have no socket +*/ + +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->thd, (char*) packet, len, net->pkt_nr); +#endif + + if (unlikely(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(key_memory_NET_compress_packet, + len + NET_HEADER_SIZE + COMP_HEADER_SIZE + 1, + MYF(MY_WME | (net->thread_specific_malloc + ? MY_THREAD_SPECIFIC : 0))))) + { + net->error= 2; + net->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); + + /* Don't compress error packets (compress == 2) */ + if (net->compress == 2 || 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_written", 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; + EXTRA_DEBUG_fprintf(stderr, + "%s: my_net_write: fcntl returned error %d, aborting thread\n", + my_progname,vio_errno(net->vio)); + net->error= 2; /* Close socket */ + net->last_errno= ER_NET_PACKET_TOO_LARGE; + MYSQL_SERVER_my_error(ER_NET_PACKET_TOO_LARGE, MYF(0)); + 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; + EXTRA_DEBUG_fprintf(stderr, "%s: write looped, aborting thread\n", + my_progname); + } +#ifndef MYSQL_SERVER + if (vio_errno(net->vio) == SOCKET_EINTR) + { + DBUG_PRINT("warning",("Interrupted write. Retrying...")); + continue; + } +#endif /* !defined(MYSQL_SERVER) */ + net->error= 2; /* Close socket */ + net->last_errno= (interrupted ? ER_NET_WRITE_INTERRUPTED : + ER_NET_ERROR_ON_WRITE); + MYSQL_SERVER_my_error(net->last_errno, MYF(0)); + break; + } + pos+=length; + update_statistics(thd_increment_bytes_sent(net->thd, length)); + } +#ifndef __WIN__ + end: +#endif +#ifdef HAVE_COMPRESS + if (net->compress) + my_free((void*) packet); +#endif + if (thr_alarm_in_use(&alarmed)) + { + my_bool old_mode; + thr_end_alarm(&alarmed); + if (!net_blocking) + 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. + + @param net Communication handle + @param remain Bytes to read + @param alarmed Parameter for thr_alarm() + @param alarm_buff Parameter for thr_alarm() + + @retval + 0 Was able to read the whole packet + @retval + 1 Got mailformed packet from client +*/ + +static my_bool my_net_skip_rest(NET *net, uint32 remain, thr_alarm_t *alarmed, + ALARM *alarm_buff) +{ + longlong limit= net->max_packet_size*net->net_skip_rest_factor; + 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(net->thd, 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= MY_MIN(remain, net->max_packet); + if (net_safe_read(net, net->buff, length, alarmed)) + DBUG_RETURN(1); + update_statistics(thd_increment_bytes_received(net->thd, length)); + remain -= (uint32) length; + limit-= length; + if (limit < 0) + DBUG_RETURN(1); + } + if (old != MAX_PACKET_LENGTH) + break; + if (net_safe_read(net, net->buff, NET_HEADER_SIZE, alarmed)) + DBUG_RETURN(1); + limit-= NET_HEADER_SIZE; + old=remain= uint3korr(net->buff); + net->pkt_nr++; + } + DBUG_RETURN(0); +} +#endif /* NO_ALARM */ + + +/** + Try to parse and process proxy protocol header. + + This function is called in case MySQL packet header cannot be parsed. + It checks if proxy header was sent, and that it was send from allowed remote + host, as defined by proxy-protocol-networks parameter. + + If proxy header is parsed, then THD and ACL structures and changed to indicate + the new peer address and port. + + Note, that proxy header can only be sent either when the connection is established, + or as the client reply packet to +*/ +#undef IGNORE /* for Windows */ +typedef enum { RETRY, ABORT, IGNORE} handle_proxy_header_result; +static handle_proxy_header_result handle_proxy_header(NET *net) +{ +#if !defined(MYSQL_SERVER) || defined(EMBEDDED_LIBRARY) + return IGNORE; +#else + THD *thd= (THD *)net->thd; + + if (!has_proxy_protocol_header(net) || !thd || + thd->get_command() != COM_CONNECT) + return IGNORE; + + /* + Proxy information found in the first 4 bytes received so far. + Read and parse proxy header , change peer ip address and port in THD. + */ + proxy_peer_info peer_info; + + if (!thd->net.vio) + { + DBUG_ASSERT(0); + return ABORT; + } + + if (!is_proxy_protocol_allowed((sockaddr *)&(thd->net.vio->remote))) + { + /* proxy-protocol-networks variable needs to be set to allow this remote address */ + my_printf_error(ER_HOST_NOT_PRIVILEGED, "Proxy header is not accepted from %s", + MYF(0), thd->main_security_ctx.ip); + return ABORT; + } + + if (parse_proxy_protocol_header(net, &peer_info)) + { + /* Failed to parse proxy header*/ + my_printf_error(ER_UNKNOWN_ERROR, "Failed to parse proxy header", MYF(0)); + return ABORT; + } + + if (peer_info.is_local_command) + /* proxy header indicates LOCAL connection, no action necessary */ + return RETRY; + /* Change peer address in THD and ACL structures.*/ + uint host_errors; + return (handle_proxy_header_result)thd_set_peer_addr(thd, + &(peer_info.peer_addr), NULL, peer_info.port, + false, &host_errors); +#endif +} + +/** + Reads one packet to net->buff + net->where_b. + Long packets are handled by my_net_read(). + This function reallocates the net->buff buffer if necessary. + + @return + Returns length of packet. +*/ + +static ulong +my_real_read(NET *net, size_t *complen, + my_bool header __attribute__((unused))) +{ + uchar *pos; + size_t length; + uint i,retry_count=0; + ulong len=packet_error; + my_bool expect_error_packet __attribute__((unused))= 0; + thr_alarm_t alarmed; +#ifndef NO_ALARM + ALARM alarm_buff; +#endif + +retry: + + my_bool net_blocking=vio_is_blocking(net->vio); + uint32 remain= (net->compress ? NET_HEADER_SIZE+COMP_HEADER_SIZE : + NET_HEADER_SIZE); +#ifdef MYSQL_SERVER + size_t count= remain; + struct st_net_server *server_extension= 0; + + if (header) + { + server_extension= static_cast<st_net_server*> (net->extension); + if (server_extension != NULL) + { + void *user_data= server_extension->m_user_data; + server_extension->m_before_header(net, user_data, count); + } + } +#endif + + *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 (i== 0 && unlikely(thd_net_is_killed((THD*) net->thd))) + { + DBUG_PRINT("info", ("thd is killed")); + len= packet_error; + net->error= 0; + net->last_errno= ER_CONNECTION_KILLED; + MYSQL_SERVER_my_error(net->last_errno, MYF(0)); + goto end; + } + +#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 the 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))); + EXTRA_DEBUG_fprintf(stderr, + "%s: read: fcntl returned error %d, aborting thread\n", + my_progname,vio_errno(net->vio)); + len= packet_error; + net->error= 2; /* Close socket */ + net->last_errno= ER_NET_FCNTL_ERROR; + MYSQL_SERVER_my_error(ER_NET_FCNTL_ERROR, MYF(0)); + 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; + EXTRA_DEBUG_fprintf(stderr, "%s: read looped with error %d, aborting thread\n", + my_progname,vio_errno(net->vio)); + } +#ifndef MYSQL_SERVER + if (length != 0 && 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->last_errno= (vio_was_timeout(net->vio) ? + ER_NET_READ_INTERRUPTED : + ER_NET_READ_ERROR); + MYSQL_SERVER_my_error(net->last_errno, MYF(0)); + goto end; + } + remain -= (uint32) length; + pos+= length; + update_statistics(thd_increment_bytes_received(net->thd, length)); + } + +#ifdef DEBUG_DATA_PACKETS + DBUG_DUMP("data_read", net->buff+net->where_b, length); +#endif + if (i == 0) + { /* First parts is packet length */ + size_t helping; +#ifndef DEBUG_DATA_PACKETS + DBUG_DUMP("packet_header", net->buff+net->where_b, + NET_HEADER_SIZE); +#endif + if (net->buff[net->where_b + 3] != (uchar) net->pkt_nr) + { +#ifndef MYSQL_SERVER + if (net->buff[net->where_b + 3] == (uchar) (net->pkt_nr -1)) + { + /* + If the server was killed then the server may have missed the + last sent client packet and the packet numbering may be one off. + */ + DBUG_PRINT("warning", ("Found possible out of order packets")); + expect_error_packet= 1; + } + else +#endif + goto packets_out_of_order; + } + net->compress_pkt_nr= ++net->pkt_nr; +#ifdef HAVE_COMPRESS + if (net->compress) + { + /* + The following uint3korr() may read 4 bytes, so make sure we don't + read unallocated or uninitialized memory. The right-hand expression + must match the size of the buffer allocated in net_realloc(). + */ + DBUG_ASSERT(net->where_b + NET_HEADER_SIZE + sizeof(uint32) <= + net->max_packet + NET_HEADER_SIZE + COMP_HEADER_SIZE + 1); + /* + 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 = MY_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; +#ifdef MYSQL_SERVER + if (server_extension != NULL) + { + void *user_data= server_extension->m_user_data; + server_extension->m_after_header(net, user_data, count, 0); + server_extension= NULL; + } +#endif + } +#ifndef MYSQL_SERVER + else if (expect_error_packet) + { + /* + This check is safe both for compressed and not compressed protocol + as for the compressed protocol errors are not compressed anymore. + */ + if (net->buff[net->where_b] != (uchar) 255) + { + /* Restore pkt_nr to original value */ + net->pkt_nr--; + goto packets_out_of_order; + } + } +#endif + } + +end: + if (thr_alarm_in_use(&alarmed)) + { + my_bool old_mode; + thr_end_alarm(&alarmed); + if (!net_blocking) + vio_blocking(net->vio, net_blocking, &old_mode); + } + net->reading_or_writing=0; +#ifdef DEBUG_DATA_PACKETS + if (len != packet_error) + DBUG_DUMP("data_read", net->buff+net->where_b, len); +#endif +#ifdef MYSQL_SERVER + if (server_extension != NULL) + { + void *user_data= server_extension->m_user_data; + server_extension->m_after_header(net, user_data, count, 1); + DBUG_ASSERT(len == packet_error || len == 0); + } +#endif + return(len); + +packets_out_of_order: + { + switch (handle_proxy_header(net)) { + case ABORT: + /* error happened, message is already written. */ + len= packet_error; + goto end; + case RETRY: + goto retry; + case IGNORE: + break; + } + + DBUG_PRINT("error", + ("Packets out of order (Found: %d, expected %u)", + (int) net->buff[net->where_b + 3], + net->pkt_nr)); + EXTRA_DEBUG_ASSERT(0); + /* + We don't make noise server side, since the client is expected + to break the protocol for e.g. --send LOAD DATA .. LOCAL where + the server expects the client to send a file, but the client + may reply with a new command instead. + */ +#ifndef MYSQL_SERVER + EXTRA_DEBUG_fflush(stdout); + EXTRA_DEBUG_fprintf(stderr,"Error: Packets out of order (Found: %d, expected %d)\n", + (int) net->buff[net->where_b + 3], + (uint) (uchar) net->pkt_nr); + EXTRA_DEBUG_fflush(stderr); +#endif + len= packet_error; + MYSQL_SERVER_my_error(ER_NET_PACKETS_OUT_OF_ORDER, MYF(0)); + goto end; + } +} + + + +/* Old interface. See my_net_read_packet() for function description */ + +#undef my_net_read + +ulong my_net_read(NET *net) +{ + return my_net_read_packet(net, 0); +} + + +/** + 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. + + read_from_server is set when the server is reading a new command + from the client. + + @return + The function returns the length of the found packet or packet_error. + net->read_pos points to the read data. +*/ +ulong +my_net_read_packet(NET *net, my_bool read_from_server) +{ + ulong reallen = 0; + return my_net_read_packet_reallen(net, read_from_server, &reallen); +} + + +ulong +my_net_read_packet_reallen(NET *net, my_bool read_from_server, ulong* reallen) +{ + size_t len, complen; + + MYSQL_NET_READ_START(); + + *reallen = 0; +#ifdef HAVE_COMPRESS + if (!net->compress) + { +#endif + len = my_real_read(net,&complen, read_from_server); + 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 += (ulong)len; + total_length += len; + len = my_real_read(net,&complen, 0); + } while (len == MAX_PACKET_LENGTH); + if (likely(len != packet_error)) + len+= total_length; + net->where_b = save_pos; + } + + net->read_pos = net->buff + net->where_b; + if (likely(len != packet_error)) + { + net->read_pos[len]=0; /* Safeguard for mysql_use_result */ + *reallen = (ulong)len; + } + MYSQL_NET_READ_DONE(0, len); + return (ulong)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, read_from_server)) + == packet_error) + { + MYSQL_NET_READ_DONE(1, 0); + return packet_error; + } + read_from_server= 0; + if (my_uncompress(net->buff + net->where_b, packet_len, + &complen)) + { + net->error= 2; /* caller will close socket */ + net->last_errno= ER_NET_UNCOMPRESS_ERROR; + MYSQL_SERVER_my_error(ER_NET_UNCOMPRESS_ERROR, MYF(0)); + MYSQL_NET_READ_DONE(1, 0); + return packet_error; + } + buf_length+= (ulong)complen; + *reallen += packet_len; + } + + 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 */ + MYSQL_NET_READ_DONE(0, len); + return (ulong)len; +} + + +void my_net_set_read_timeout(NET *net, uint timeout) +{ + DBUG_ENTER("my_net_set_read_timeout"); + DBUG_PRINT("enter", ("timeout: %d", timeout)); + if (net->read_timeout != timeout) + { + net->read_timeout= timeout; + if (net->vio) + vio_timeout(net->vio, 0, timeout); + } + 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)); + if (net->write_timeout != timeout) + { + net->write_timeout= timeout; + if (net->vio) + vio_timeout(net->vio, 1, timeout); + } + DBUG_VOID_RETURN; +} |