// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Namjae Jeon <[email protected]>
* Copyright (C) 2018 Samsung Electronics Co., Ltd.
*/
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/module.h>
#include "server.h"
#include "smb_common.h"
#include "mgmt/ksmbd_ida.h"
#include "connection.h"
#include "transport_tcp.h"
#include "transport_rdma.h"
static DEFINE_MUTEX(init_lock);
static struct ksmbd_conn_ops default_conn_ops;
LIST_HEAD(conn_list);
DECLARE_RWSEM(conn_list_lock);
/**
* ksmbd_conn_free() - free resources of the connection instance
*
* @conn: connection instance to be cleaned up
*
* During the thread termination, the corresponding conn instance
* resources(sock/memory) are released and finally the conn object is freed.
*/
void ksmbd_conn_free(struct ksmbd_conn *conn)
{
down_write(&conn_list_lock);
list_del(&conn->conns_list);
up_write(&conn_list_lock);
xa_destroy(&conn->sessions);
kvfree(conn->request_buf);
kfree(conn->preauth_info);
if (atomic_dec_and_test(&conn->refcnt))
kfree(conn);
}
/**
* ksmbd_conn_alloc() - initialize a new connection instance
*
* Return: ksmbd_conn struct on success, otherwise NULL
*/
struct ksmbd_conn *ksmbd_conn_alloc(void)
{
struct ksmbd_conn *conn;
conn = kzalloc(sizeof(struct ksmbd_conn), GFP_KERNEL);
if (!conn)
return NULL;
conn->need_neg = true;
ksmbd_conn_set_new(conn);
conn->local_nls = load_nls("utf8");
if (!conn->local_nls)
conn->local_nls = load_nls_default();
if (IS_ENABLED(CONFIG_UNICODE))
conn->um = utf8_load(UNICODE_AGE(12, 1, 0));
else
conn->um = ERR_PTR(-EOPNOTSUPP);
if (IS_ERR(conn->um))
conn->um = NULL;
atomic_set(&conn->req_running, 0);
atomic_set(&conn->r_count, 0);
atomic_set(&conn->refcnt, 1);
conn->total_credits = 1;
conn->outstanding_credits = 0;
init_waitqueue_head(&conn->req_running_q);
init_waitqueue_head(&conn->r_count_q);
INIT_LIST_HEAD(&conn->conns_list);
INIT_LIST_HEAD(&conn->requests);
INIT_LIST_HEAD(&conn->async_requests);
spin_lock_init(&conn->request_lock);
spin_lock_init(&conn->credits_lock);
ida_init(&conn->async_ida);
xa_init(&conn->sessions);
spin_lock_init(&conn->llist_lock);
INIT_LIST_HEAD(&conn->lock_list);
init_rwsem(&conn->session_lock);
down_write(&conn_list_lock);
list_add(&conn->conns_list, &conn_list);
up_write(&conn_list_lock);
return conn;
}
bool ksmbd_conn_lookup_dialect(struct ksmbd_conn *c)
{
struct ksmbd_conn *t;
bool ret = false;
down_read(&conn_list_lock);
list_for_each_entry(t, &conn_list, conns_list) {
if (memcmp(t->ClientGUID, c->ClientGUID, SMB2_CLIENT_GUID_SIZE))
continue;
ret = true;
break;
}
up_read(&conn_list_lock);
return ret;
}
void ksmbd_conn_enqueue_request(struct ksmbd_work *work)
{
struct ksmbd_conn *conn = work->conn;
struct list_head *requests_queue = NULL;
if (conn->ops->get_cmd_val(work) != SMB2_CANCEL_HE)
requests_queue = &conn->requests;
if (requests_queue) {
atomic_inc(&conn->req_running);
spin_lock(&conn->request_lock);
list_add_tail(&work->request_entry, requests_queue);
spin_unlock(&conn->request_lock);
}
}
void ksmbd_conn_try_dequeue_request(struct ksmbd_work *work)
{
struct ksmbd_conn *conn = work->conn;
if (list_empty(&work->request_entry) &&
list_empty(&work->async_request_entry))
return;
atomic_dec(&conn->req_running);
spin_lock(&conn->request_lock);
list_del_init(&work->request_entry);
spin_unlock(&conn->request_lock);
if (work->asynchronous)
release_async_work(work);
wake_up_all(&conn->req_running_q);
}
void ksmbd_conn_lock(struct ksmbd_conn *conn)
{
mutex_lock(&conn->srv_mutex);
}
void ksmbd_conn_unlock(struct ksmbd_conn *conn)
{
mutex_unlock(&conn->srv_mutex);
}
void ksmbd_all_conn_set_status(u64 sess_id, u32 status)
{
struct ksmbd_conn *conn;
down_read(&conn_list_lock);
list_for_each_entry(conn, &conn_list, conns_list) {
if (conn->binding || xa_load(&conn->sessions, sess_id))
WRITE_ONCE(conn->status, status);
}
up_read(&conn_list_lock);
}
void ksmbd_conn_wait_idle(struct ksmbd_conn *conn)
{
wait_event(conn->req_running_q, atomic_read(&conn->req_running) < 2);
}
int ksmbd_conn_wait_idle_sess_id(struct ksmbd_conn *curr_conn, u64 sess_id)
{
struct ksmbd_conn *conn;
int rc, retry_count = 0, max_timeout = 120;
int rcount = 1;
retry_idle:
if (retry_count >= max_timeout)
return -EIO;
down_read(&conn_list_lock);
list_for_each_entry(conn, &conn_list, conns_list) {
if (conn->binding || xa_load(&conn->sessions, sess_id)) {
if (conn == curr_conn)
rcount = 2;
if (atomic_read(&conn->req_running) >= rcount) {
rc = wait_event_timeout(conn->req_running_q,
atomic_read(&conn->req_running) < rcount,
HZ);
if (!rc) {
up_read(&conn_list_lock);
retry_count++;
goto retry_idle;
}
}
}
}
up_read(&conn_list_lock);
return 0;
}
int ksmbd_conn_write(struct ksmbd_work *work)
{
struct ksmbd_conn *conn = work->conn;
int sent;
if (!work->response_buf) {
pr_err("NULL response header\n");
return -EINVAL;
}
if (work->send_no_response)
return 0;
if (!work->iov_idx)
return -EINVAL;
ksmbd_conn_lock(conn);
sent = conn->transport->ops->writev(conn->transport, work->iov,
work->iov_cnt,
get_rfc1002_len(work->iov[0].iov_base) + 4,
work->need_invalidate_rkey,
work->remote_key);
ksmbd_conn_unlock(conn);
if (sent < 0) {
pr_err("Failed to send message: %d\n", sent);
return sent;
}
return 0;
}
int ksmbd_conn_rdma_read(struct ksmbd_conn *conn,
void *buf, unsigned int buflen,
struct smb2_buffer_desc_v1 *desc,
unsigned int desc_len)
{
int ret = -EINVAL;
if (conn->transport->ops->rdma_read)
ret = conn->transport->ops->rdma_read(conn->transport,
buf, buflen,
desc, desc_len);
return ret;
}
int ksmbd_conn_rdma_write(struct ksmbd_conn *conn,
void *buf, unsigned int buflen,
struct smb2_buffer_desc_v1 *desc,
unsigned int desc_len)
{
int ret = -EINVAL;
if (conn->transport->ops->rdma_write)
ret = conn->transport->ops->rdma_write(conn->transport,
buf, buflen,
desc, desc_len);
return ret;
}
bool ksmbd_conn_alive(struct ksmbd_conn *conn)
{
if (!ksmbd_server_running())
return false;
if (ksmbd_conn_exiting(conn))
return false;
if (kthread_should_stop())
return false;
if (atomic_read(&conn->stats.open_files_count) > 0)
return true;
/*
* Stop current session if the time that get last request from client
* is bigger than deadtime user configured and opening file count is
* zero.
*/
if (server_conf.deadtime > 0 &&
time_after(jiffies, conn->last_active + server_conf.deadtime)) {
ksmbd_debug(CONN, "No response from client in %lu minutes\n",
server_conf.deadtime / SMB_ECHO_INTERVAL);
return false;
}
return true;
}
#define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr))
#define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
/**
* ksmbd_conn_handler_loop() - session thread to listen on new smb requests
* @p: connection instance
*
* One thread each per connection
*
* Return: 0 on success
*/
int ksmbd_conn_handler_loop(void *p)
{
struct ksmbd_conn *conn = (struct ksmbd_conn *)p;
struct ksmbd_transport *t = conn->transport;
unsigned int pdu_size, max_allowed_pdu_size;
char hdr_buf[4] = {0,};
int size;
mutex_init(&conn->srv_mutex);
__module_get(THIS_MODULE);
if (t->ops->prepare && t->ops->prepare(t))
goto out;
conn->last_active = jiffies;
set_freezable();
while (ksmbd_conn_alive(conn)) {
if (try_to_freeze())
continue;
kvfree(conn->request_buf);
conn->request_buf = NULL;
size = t->ops->read(t, hdr_buf, sizeof(hdr_buf), -1);
if (size != sizeof(hdr_buf))
break;
pdu_size = get_rfc1002_len(hdr_buf);
ksmbd_debug(CONN, "RFC1002 header %u bytes\n", pdu_size);
if (ksmbd_conn_good(conn))
max_allowed_pdu_size =
SMB3_MAX_MSGSIZE + conn->vals->max_write_size;
else
max_allowed_pdu_size = SMB3_MAX_MSGSIZE;
if (pdu_size > max_allowed_pdu_size) {
pr_err_ratelimited("PDU length(%u) exceeded maximum allowed pdu size(%u) on connection(%d)\n",
pdu_size, max_allowed_pdu_size,
READ_ONCE(conn->status));
break;
}
/*
* Check maximum pdu size(0x00FFFFFF).
*/
if (pdu_size > MAX_STREAM_PROT_LEN)
break;
if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE)
break;
/* 4 for rfc1002 length field */
/* 1 for implied bcc[0] */
size = pdu_size + 4 + 1;
conn->request_buf = kvmalloc(size, GFP_KERNEL);
if (!conn->request_buf)
break;
memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf));
/*
* We already read 4 bytes to find out PDU size, now
* read in PDU
*/
size = t->ops->read(t, conn->request_buf + 4, pdu_size, 2);
if (size < 0) {
pr_err("sock_read failed: %d\n", size);
break;
}
if (size != pdu_size) {
pr_err("PDU error. Read: %d, Expected: %d\n",
size, pdu_size);
continue;
}
if (!ksmbd_smb_request(conn))
break;
if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId ==
SMB2_PROTO_NUMBER) {
if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
break;
}
if (!default_conn_ops.process_fn) {
pr_err("No connection request callback\n");
break;
}
if (default_conn_ops.process_fn(conn)) {
pr_err("Cannot handle request\n");
break;
}
}
out:
ksmbd_conn_set_releasing(conn);
/* Wait till all reference dropped to the Server object*/
wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
if (IS_ENABLED(CONFIG_UNICODE))
utf8_unload(conn->um);
unload_nls(conn->local_nls);
if (default_conn_ops.terminate_fn)
default_conn_ops.terminate_fn(conn);
t->ops->disconnect(t);
module_put(THIS_MODULE);
return 0;
}
void ksmbd_conn_init_server_callbacks(struct ksmbd_conn_ops *ops)
{
default_conn_ops.process_fn = ops->process_fn;
default_conn_ops.terminate_fn = ops->terminate_fn;
}
int ksmbd_conn_transport_init(void)
{
int ret;
mutex_lock(&init_lock);
ret = ksmbd_tcp_init();
if (ret) {
pr_err("Failed to init TCP subsystem: %d\n", ret);
goto out;
}
ret = ksmbd_rdma_init();
if (ret) {
pr_err("Failed to init RDMA subsystem: %d\n", ret);
goto out;
}
out:
mutex_unlock(&init_lock);
return ret;
}
static void stop_sessions(void)
{
struct ksmbd_conn *conn;
struct ksmbd_transport *t;
again:
down_read(&conn_list_lock);
list_for_each_entry(conn, &conn_list, conns_list) {
t = conn->transport;
ksmbd_conn_set_exiting(conn);
if (t->ops->shutdown) {
up_read(&conn_list_lock);
t->ops->shutdown(t);
down_read(&conn_list_lock);
}
}
up_read(&conn_list_lock);
if (!list_empty(&conn_list)) {
schedule_timeout_interruptible(HZ / 10); /* 100ms */
goto again;
}
}
void ksmbd_conn_transport_destroy(void)
{
mutex_lock(&init_lock);
ksmbd_tcp_destroy();
ksmbd_rdma_destroy();
stop_sessions();
mutex_unlock(&init_lock);
}
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