2019-06-25 10:11:55 +03:00

411 lines
11 KiB
C++

/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2023-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#define MXS_MODULE_NAME "maxscaled"
#include <maxscale/ccdefs.hh>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <maxscale/dcb.hh>
#include <maxscale/buffer.hh>
#include <maxscale/protocol.hh>
#include <maxscale/service.hh>
#include <maxscale/session.hh>
#include <sys/ioctl.h>
#include <errno.h>
#include <pwd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <maxscale/router.hh>
#include <maxscale/poll.hh>
#include <maxbase/atomic.h>
#include <maxscale/adminusers.h>
#include <maxscale/modinfo.h>
#include "maxscaled.hh"
#include <maxscale/maxadmin.h>
#include <maxbase/alloc.h>
/**
* @file maxscaled.c - MaxScale administration protocol
*
*
* @verbatim
* Revision History
* Date Who Description
* 13/06/2014 Mark Riddoch Initial implementation
* 07/07/2015 Martin Brampton Correct failure handling
* 17/05/2016 Massimiliano Pinto Check for UNIX socket address
*
* @endverbatim
*/
#define GETPWUID_BUF_LEN 255
static int maxscaled_read_event(DCB* dcb);
static int maxscaled_write_event(DCB* dcb);
static int maxscaled_write(DCB* dcb, GWBUF* queue);
static int maxscaled_error(DCB* dcb);
static int maxscaled_hangup(DCB* dcb);
static int maxscaled_accept(DCB*);
static int maxscaled_close(DCB* dcb);
static char* mxsd_default_auth();
static bool authenticate_unix_socket(MAXSCALED* protocol, DCB* dcb)
{
bool authenticated = false;
struct ucred ucred;
socklen_t len = sizeof(struct ucred);
/* Get UNIX client credentials from socket*/
if (getsockopt(dcb->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) == 0)
{
struct passwd pw_entry;
struct passwd* pw_tmp;
char buf[GETPWUID_BUF_LEN];
/* Fetch username from UID */
if (getpwuid_r(ucred.uid, &pw_entry, buf, sizeof(buf), &pw_tmp) == 0)
{
GWBUF* username;
/* Set user in protocol */
protocol->username = strdup(pw_entry.pw_name);
username = gwbuf_alloc(strlen(protocol->username) + 1);
strcpy((char*)GWBUF_DATA(username), protocol->username);
/* Authenticate the user */
if (dcb->authfunc.extract(dcb, username)
&& dcb->authfunc.authenticate(dcb) == 0)
{
dcb_printf(dcb, MAXADMIN_AUTH_SUCCESS_REPLY);
protocol->state = MAXSCALED_STATE_DATA;
dcb->user = strdup(protocol->username);
}
else
{
dcb_printf(dcb, MAXADMIN_AUTH_FAILED_REPLY);
}
gwbuf_free(username);
authenticated = true;
}
else
{
MXS_ERROR("Failed to get UNIX user %ld details for 'MaxScale Admin'",
(unsigned long)ucred.uid);
}
}
else
{
MXS_ERROR("Failed to get UNIX domain socket credentials for 'MaxScale Admin'.");
}
return authenticated;
}
static bool authenticate_inet_socket(MAXSCALED* protocol, DCB* dcb)
{
dcb_printf(dcb, MAXADMIN_AUTH_USER_PROMPT);
return true;
}
static bool authenticate_socket(MAXSCALED* protocol, DCB* dcb)
{
bool authenticated = false;
struct sockaddr address;
socklen_t address_len = sizeof(address);
if (getsockname(dcb->fd, &address, &address_len) == 0)
{
if (address.sa_family == AF_UNIX)
{
authenticated = authenticate_unix_socket(protocol, dcb);
}
else
{
authenticated = authenticate_inet_socket(protocol, dcb);
}
}
else
{
MXS_ERROR("Could not get socket family of client connection: %s",
mxs_strerror(errno));
}
return authenticated;
}
extern "C"
{
/**
* The module entry point routine. It is this routine that
* must populate the structure that is referred to as the
* "module object", this is a structure with the set of
* external entry points for this module.
*
* @return The module object
*/
MXS_MODULE* MXS_CREATE_MODULE()
{
MXS_INFO("Initialise MaxScaled Protocol module.");
static MXS_PROTOCOL MyObject =
{
maxscaled_read_event, /**< Read - EPOLLIN handler */
maxscaled_write, /**< Write - data from gateway */
maxscaled_write_event, /**< WriteReady - EPOLLOUT handler */
maxscaled_error, /**< Error - EPOLLERR handler */
maxscaled_hangup, /**< HangUp - EPOLLHUP handler */
maxscaled_accept, /**< Accept */
NULL, /**< Connect */
maxscaled_close, /**< Close */
NULL, /**< Authentication */
mxsd_default_auth, /**< Default authenticator */
NULL, /**< Connection limit reached */
NULL,
NULL,
};
static MXS_MODULE info =
{
MXS_MODULE_API_PROTOCOL,
MXS_MODULE_GA,
MXS_PROTOCOL_VERSION,
"A maxscale protocol for the administration interface",
"V2.0.0",
MXS_NO_MODULE_CAPABILITIES,
&MyObject,
NULL, /* Process init. */
NULL, /* Process finish. */
NULL, /* Thread init. */
NULL, /* Thread finish. */
{
{MXS_END_MODULE_PARAMS}
}
};
return &info;
}
}
/*lint +e14 */
/**
* The default authenticator name for this protocol
*
* @return name of authenticator
*/
static char* mxsd_default_auth()
{
return const_cast<char*>("MaxAdminAuth");
}
/**
* Read event for EPOLLIN on the maxscaled protocol module.
*
* @param dcb The descriptor control block
* @return
*/
static int maxscaled_read_event(DCB* dcb)
{
int n;
GWBUF* head = NULL;
MAXSCALED* maxscaled = (MAXSCALED*)dcb->protocol;
if ((n = dcb_read(dcb, &head, 0)) != -1)
{
if (head)
{
if (GWBUF_LENGTH(head))
{
switch (maxscaled->state)
{
case MAXSCALED_STATE_LOGIN:
{
size_t len = GWBUF_LENGTH(head);
char user[len + 1];
memcpy(user, GWBUF_DATA(head), len);
user[len] = '\0';
maxscaled->username = MXS_STRDUP_A(user);
dcb->user = MXS_STRDUP_A(user);
maxscaled->state = MAXSCALED_STATE_PASSWD;
dcb_printf(dcb, MAXADMIN_AUTH_PASSWORD_PROMPT);
gwbuf_free(head);
}
break;
case MAXSCALED_STATE_PASSWD:
{
char* password = strndup((char*)GWBUF_DATA(head), GWBUF_LENGTH(head));
if (admin_verify_inet_user(maxscaled->username, password))
{
dcb_printf(dcb, MAXADMIN_AUTH_SUCCESS_REPLY);
maxscaled->state = MAXSCALED_STATE_DATA;
}
else
{
dcb_printf(dcb, MAXADMIN_AUTH_FAILED_REPLY);
maxscaled->state = MAXSCALED_STATE_LOGIN;
}
gwbuf_free(head);
free(password);
}
break;
case MAXSCALED_STATE_DATA:
{
MXS_SESSION_ROUTE_QUERY(dcb->session, head);
dcb_printf(dcb, "OK");
}
break;
}
}
else
{
// Force the free of the buffer header
gwbuf_free(head);
}
}
}
return n;
}
/**
* EPOLLOUT handler for the maxscaled protocol module.
*
* @param dcb The descriptor control block
* @return
*/
static int maxscaled_write_event(DCB* dcb)
{
return dcb_drain_writeq(dcb);
}
/**
* Write routine for the maxscaled protocol module.
*
* Writes the content of the buffer queue to the socket
* observing the non-blocking principles of MaxScale.
*
* @param dcb Descriptor Control Block for the socket
* @param queue Linked list of buffes to write
*/
static int maxscaled_write(DCB* dcb, GWBUF* queue)
{
int rc;
rc = dcb_write(dcb, queue);
return rc;
}
/**
* Handler for the EPOLLERR event.
*
* @param dcb The descriptor control block
*/
static int maxscaled_error(DCB* dcb)
{
return 0;
}
/**
* Handler for the EPOLLHUP event.
*
* @param dcb The descriptor control block
*/
static int maxscaled_hangup(DCB* dcb)
{
dcb_close(dcb);
return 0;
}
/**
* Handler for the EPOLLIN event when the DCB refers to the listening
* socket for the protocol.
*
* @param dcb The descriptor control block
* @return The number of new connections created
*/
static int maxscaled_accept(DCB* client_dcb)
{
socklen_t len = sizeof(struct ucred);
struct ucred ucred;
MAXSCALED* maxscaled_protocol = (MAXSCALED*)calloc(1, sizeof(MAXSCALED));
if (!maxscaled_protocol)
{
dcb_close(client_dcb);
return 0;
}
maxscaled_protocol->username = NULL;
maxscaled_protocol->state = MAXSCALED_STATE_LOGIN;
bool authenticated = false;
if (!authenticate_socket(maxscaled_protocol, client_dcb))
{
dcb_close(client_dcb);
free(maxscaled_protocol);
return 0;
}
pthread_mutex_init(&maxscaled_protocol->lock, NULL);
client_dcb->protocol = (void*)maxscaled_protocol;
if (!session_start(client_dcb->session) || poll_add_dcb(client_dcb))
{
dcb_close(client_dcb);
return 0;
}
return 1;
}
/**
* The close handler for the descriptor. Called by the gateway to
* explicitly close a connection.
*
* @param dcb The descriptor control block
*/
static int maxscaled_close(DCB* dcb)
{
MAXSCALED* maxscaled = static_cast<MAXSCALED*>(dcb->protocol);
if (!maxscaled)
{
return 0;
}
pthread_mutex_lock(&maxscaled->lock);
if (maxscaled->username)
{
MXS_FREE(maxscaled->username);
maxscaled->username = NULL;
}
pthread_mutex_unlock(&maxscaled->lock);
return 0;
}