diff options
Diffstat (limited to 'sql/net_serv.cc')
| -rw-r--r-- | sql/net_serv.cc | 85 |
1 files changed, 74 insertions, 11 deletions
diff --git a/sql/net_serv.cc b/sql/net_serv.cc index 7326c0395e3..ef56f0d77e2 100644 --- a/sql/net_serv.cc +++ b/sql/net_serv.cc @@ -194,30 +194,93 @@ my_bool net_realloc(NET *net, ulong length) DBUG_RETURN(0); } - /* Remove unwanted characters from connection */ + +/* + 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 +*/ + +static my_bool net_data_is_ready(my_socket sd) +{ + fd_set sfds; + struct timeval tv; + int res; + + 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 FALSE; + else + return test(res ? FD_ISSET(sd, &sfds) : 0); +} + + +/* + Remove unwanted characters from connection + and check if disconnected + + SYNOPSIS + net_clear() + net NET handler + + 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) { + int count; DBUG_ENTER("net_clear"); -#if !defined(EXTRA_DEBUG) && !defined(EMBEDDED_LIBRARY) +#if !defined(EMBEDDED_LIBRARY) + while(net_data_is_ready(net->vio->sd)) { - int count; /* One may get 'unused' warn */ - my_bool old_mode; - if (!vio_blocking(net->vio, FALSE, &old_mode)) + /* The socket is ready */ + if ((count= vio_read(net->vio, (char*) (net->buff), + (uint32) net->max_packet)) > 0) { - while ((count = vio_read(net->vio, (char*) (net->buff), - (uint32) net->max_packet)) > 0) - DBUG_PRINT("info",("skipped %d bytes from file: %s", - count, vio_description(net->vio))); - vio_blocking(net->vio, TRUE, &old_mode); + DBUG_PRINT("info",("skipped %d bytes from file: %s", + count, vio_description(net->vio))); +#ifdef EXTRA_DEBUG + fprintf(stderr,"skipped %d bytes from file: %s\n", + count, vio_description(net->vio)); +#endif + } + else + { + DBUG_PRINT("info",("socket ready but only EOF to read - disconnected")); + net->error= 2; + break; } } -#endif /* EXTRA_DEBUG */ +#endif 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) |