linux/drivers/target/iscsi/iscsi_target_nego.c
Maurizio Lombardi fec1b2fa62 scsi: target: iscsi: Fix a race condition between login_work and the login thread
In case a malicious initiator sends some random data immediately after a
login PDU; the iscsi_target_sk_data_ready() callback will schedule the
login_work and, at the same time, the negotiation may end without clearing
the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are
required to complete the login).

The login has been completed but the login_work function will find the
LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling
itself; at this point, if the initiator drops the connection, the
iscsit_conn structure will be freed, login_work will dereference a released
socket structure and the kernel crashes.

BUG: kernel NULL pointer dereference, address: 0000000000000230
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
RIP: 0010:_raw_read_lock_bh+0x15/0x30
Call trace:
 iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod]
 process_one_work+0x1e8/0x3c0

Fix this bug by forcing login_work to stop after the login has been
completed and the socket callbacks have been restored.

Add a comment to clearify the return values of iscsi_target_do_login()

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20221115125638.102517-1-mlombard@redhat.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2022-11-24 03:22:53 +00:00

1397 lines
37 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
* This file contains main functions related to iSCSI Parameter negotiation.
*
* (c) Copyright 2007-2013 Datera, Inc.
*
* Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
*
******************************************************************************/
#include <linux/ctype.h>
#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <net/sock.h>
#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/iscsi/iscsi_transport.h>
#include <target/iscsi/iscsi_target_core.h>
#include "iscsi_target_parameters.h"
#include "iscsi_target_login.h"
#include "iscsi_target_nego.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_util.h"
#include "iscsi_target.h"
#include "iscsi_target_auth.h"
#define MAX_LOGIN_PDUS 7
void convert_null_to_semi(char *buf, int len)
{
int i;
for (i = 0; i < len; i++)
if (buf[i] == '\0')
buf[i] = ';';
}
static int strlen_semi(char *buf)
{
int i = 0;
while (buf[i] != '\0') {
if (buf[i] == ';')
return i;
i++;
}
return -1;
}
int extract_param(
const char *in_buf,
const char *pattern,
unsigned int max_length,
char *out_buf,
unsigned char *type)
{
char *ptr;
int len;
if (!in_buf || !pattern || !out_buf || !type)
return -EINVAL;
ptr = strstr(in_buf, pattern);
if (!ptr)
return -ENOENT;
ptr = strstr(ptr, "=");
if (!ptr)
return -EINVAL;
ptr += 1;
if (*ptr == '0' && (*(ptr+1) == 'x' || *(ptr+1) == 'X')) {
ptr += 2; /* skip 0x */
*type = HEX;
} else if (*ptr == '0' && (*(ptr+1) == 'b' || *(ptr+1) == 'B')) {
ptr += 2; /* skip 0b */
*type = BASE64;
} else
*type = DECIMAL;
len = strlen_semi(ptr);
if (len < 0)
return -EINVAL;
if (len >= max_length) {
pr_err("Length of input: %d exceeds max_length:"
" %d\n", len, max_length);
return -EINVAL;
}
memcpy(out_buf, ptr, len);
out_buf[len] = '\0';
return 0;
}
static struct iscsi_node_auth *iscsi_get_node_auth(struct iscsit_conn *conn)
{
struct iscsi_portal_group *tpg;
struct iscsi_node_acl *nacl;
struct se_node_acl *se_nacl;
if (conn->sess->sess_ops->SessionType)
return &iscsit_global->discovery_acl.node_auth;
se_nacl = conn->sess->se_sess->se_node_acl;
if (!se_nacl) {
pr_err("Unable to locate struct se_node_acl for CHAP auth\n");
return NULL;
}
if (se_nacl->dynamic_node_acl) {
tpg = to_iscsi_tpg(se_nacl->se_tpg);
return &tpg->tpg_demo_auth;
}
nacl = to_iscsi_nacl(se_nacl);
return &nacl->node_auth;
}
static u32 iscsi_handle_authentication(
struct iscsit_conn *conn,
char *in_buf,
char *out_buf,
int in_length,
int *out_length,
unsigned char *authtype)
{
struct iscsi_node_auth *auth;
auth = iscsi_get_node_auth(conn);
if (!auth)
return -1;
if (strstr("CHAP", authtype))
strcpy(conn->sess->auth_type, "CHAP");
else
strcpy(conn->sess->auth_type, NONE);
if (strstr("None", authtype))
return 1;
else if (strstr("CHAP", authtype))
return chap_main_loop(conn, auth, in_buf, out_buf,
&in_length, out_length);
/* SRP, SPKM1, SPKM2 and KRB5 are unsupported */
return 2;
}
static void iscsi_remove_failed_auth_entry(struct iscsit_conn *conn)
{
kfree(conn->auth_protocol);
}
int iscsi_target_check_login_request(
struct iscsit_conn *conn,
struct iscsi_login *login)
{
int req_csg, req_nsg;
u32 payload_length;
struct iscsi_login_req *login_req;
login_req = (struct iscsi_login_req *) login->req;
payload_length = ntoh24(login_req->dlength);
switch (login_req->opcode & ISCSI_OPCODE_MASK) {
case ISCSI_OP_LOGIN:
break;
default:
pr_err("Received unknown opcode 0x%02x.\n",
login_req->opcode & ISCSI_OPCODE_MASK);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if ((login_req->flags & ISCSI_FLAG_LOGIN_CONTINUE) &&
(login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
pr_err("Login request has both ISCSI_FLAG_LOGIN_CONTINUE"
" and ISCSI_FLAG_LOGIN_TRANSIT set, protocol error.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
req_csg = ISCSI_LOGIN_CURRENT_STAGE(login_req->flags);
req_nsg = ISCSI_LOGIN_NEXT_STAGE(login_req->flags);
if (req_csg != login->current_stage) {
pr_err("Initiator unexpectedly changed login stage"
" from %d to %d, login failed.\n", login->current_stage,
req_csg);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if ((req_nsg == 2) || (req_csg >= 2) ||
((login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT) &&
(req_nsg <= req_csg))) {
pr_err("Illegal login_req->flags Combination, CSG: %d,"
" NSG: %d, ISCSI_FLAG_LOGIN_TRANSIT: %d.\n", req_csg,
req_nsg, (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT));
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if ((login_req->max_version != login->version_max) ||
(login_req->min_version != login->version_min)) {
pr_err("Login request changed Version Max/Nin"
" unexpectedly to 0x%02x/0x%02x, protocol error\n",
login_req->max_version, login_req->min_version);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if (memcmp(login_req->isid, login->isid, 6) != 0) {
pr_err("Login request changed ISID unexpectedly,"
" protocol error.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if (login_req->itt != login->init_task_tag) {
pr_err("Login request changed ITT unexpectedly to"
" 0x%08x, protocol error.\n", login_req->itt);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if (payload_length > MAX_KEY_VALUE_PAIRS) {
pr_err("Login request payload exceeds default"
" MaxRecvDataSegmentLength: %u, protocol error.\n",
MAX_KEY_VALUE_PAIRS);
return -1;
}
return 0;
}
EXPORT_SYMBOL(iscsi_target_check_login_request);
static int iscsi_target_check_first_request(
struct iscsit_conn *conn,
struct iscsi_login *login)
{
struct iscsi_param *param = NULL;
struct se_node_acl *se_nacl;
login->first_request = 0;
list_for_each_entry(param, &conn->param_list->param_list, p_list) {
if (!strncmp(param->name, SESSIONTYPE, 11)) {
if (!IS_PSTATE_ACCEPTOR(param)) {
pr_err("SessionType key not received"
" in first login request.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_MISSING_FIELDS);
return -1;
}
if (!strncmp(param->value, DISCOVERY, 9))
return 0;
}
if (!strncmp(param->name, INITIATORNAME, 13)) {
if (!IS_PSTATE_ACCEPTOR(param)) {
if (!login->leading_connection)
continue;
pr_err("InitiatorName key not received"
" in first login request.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_MISSING_FIELDS);
return -1;
}
/*
* For non-leading connections, double check that the
* received InitiatorName matches the existing session's
* struct iscsi_node_acl.
*/
if (!login->leading_connection) {
se_nacl = conn->sess->se_sess->se_node_acl;
if (!se_nacl) {
pr_err("Unable to locate"
" struct se_node_acl\n");
iscsit_tx_login_rsp(conn,
ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
return -1;
}
if (strcmp(param->value,
se_nacl->initiatorname)) {
pr_err("Incorrect"
" InitiatorName: %s for this"
" iSCSI Initiator Node.\n",
param->value);
iscsit_tx_login_rsp(conn,
ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
return -1;
}
}
}
}
return 0;
}
static int iscsi_target_do_tx_login_io(struct iscsit_conn *conn, struct iscsi_login *login)
{
u32 padding = 0;
struct iscsi_login_rsp *login_rsp;
login_rsp = (struct iscsi_login_rsp *) login->rsp;
login_rsp->opcode = ISCSI_OP_LOGIN_RSP;
hton24(login_rsp->dlength, login->rsp_length);
memcpy(login_rsp->isid, login->isid, 6);
login_rsp->tsih = cpu_to_be16(login->tsih);
login_rsp->itt = login->init_task_tag;
login_rsp->statsn = cpu_to_be32(conn->stat_sn++);
login_rsp->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
login_rsp->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
pr_debug("Sending Login Response, Flags: 0x%02x, ITT: 0x%08x,"
" ExpCmdSN; 0x%08x, MaxCmdSN: 0x%08x, StatSN: 0x%08x, Length:"
" %u\n", login_rsp->flags, (__force u32)login_rsp->itt,
ntohl(login_rsp->exp_cmdsn), ntohl(login_rsp->max_cmdsn),
ntohl(login_rsp->statsn), login->rsp_length);
padding = ((-login->rsp_length) & 3);
/*
* Before sending the last login response containing the transition
* bit for full-feature-phase, go ahead and start up TX/RX threads
* now to avoid potential resource allocation failures after the
* final login response has been sent.
*/
if (login->login_complete) {
int rc = iscsit_start_kthreads(conn);
if (rc) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
return -1;
}
}
if (conn->conn_transport->iscsit_put_login_tx(conn, login,
login->rsp_length + padding) < 0)
goto err;
login->rsp_length = 0;
return 0;
err:
if (login->login_complete) {
if (conn->rx_thread && conn->rx_thread_active) {
send_sig(SIGINT, conn->rx_thread, 1);
complete(&conn->rx_login_comp);
kthread_stop(conn->rx_thread);
}
if (conn->tx_thread && conn->tx_thread_active) {
send_sig(SIGINT, conn->tx_thread, 1);
kthread_stop(conn->tx_thread);
}
spin_lock(&iscsit_global->ts_bitmap_lock);
bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
get_order(1));
spin_unlock(&iscsit_global->ts_bitmap_lock);
}
return -1;
}
static void iscsi_target_sk_data_ready(struct sock *sk)
{
struct iscsit_conn *conn = sk->sk_user_data;
bool rc;
pr_debug("Entering iscsi_target_sk_data_ready: conn: %p\n", conn);
write_lock_bh(&sk->sk_callback_lock);
if (!sk->sk_user_data) {
write_unlock_bh(&sk->sk_callback_lock);
return;
}
if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
write_unlock_bh(&sk->sk_callback_lock);
pr_debug("Got LOGIN_FLAGS_READY=0, conn: %p >>>>\n", conn);
return;
}
if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
write_unlock_bh(&sk->sk_callback_lock);
pr_debug("Got LOGIN_FLAGS_CLOSED=1, conn: %p >>>>\n", conn);
return;
}
if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {
write_unlock_bh(&sk->sk_callback_lock);
pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn);
if (iscsi_target_sk_data_ready == conn->orig_data_ready)
return;
conn->orig_data_ready(sk);
return;
}
rc = schedule_delayed_work(&conn->login_work, 0);
if (!rc) {
pr_debug("iscsi_target_sk_data_ready, schedule_delayed_work"
" got false\n");
}
write_unlock_bh(&sk->sk_callback_lock);
}
static void iscsi_target_sk_state_change(struct sock *);
static void iscsi_target_set_sock_callbacks(struct iscsit_conn *conn)
{
struct sock *sk;
if (!conn->sock)
return;
sk = conn->sock->sk;
pr_debug("Entering iscsi_target_set_sock_callbacks: conn: %p\n", conn);
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = conn;
conn->orig_data_ready = sk->sk_data_ready;
conn->orig_state_change = sk->sk_state_change;
sk->sk_data_ready = iscsi_target_sk_data_ready;
sk->sk_state_change = iscsi_target_sk_state_change;
write_unlock_bh(&sk->sk_callback_lock);
sk->sk_sndtimeo = TA_LOGIN_TIMEOUT * HZ;
sk->sk_rcvtimeo = TA_LOGIN_TIMEOUT * HZ;
}
static void iscsi_target_restore_sock_callbacks(struct iscsit_conn *conn)
{
struct sock *sk;
if (!conn->sock)
return;
sk = conn->sock->sk;
pr_debug("Entering iscsi_target_restore_sock_callbacks: conn: %p\n", conn);
write_lock_bh(&sk->sk_callback_lock);
if (!sk->sk_user_data) {
write_unlock_bh(&sk->sk_callback_lock);
return;
}
sk->sk_user_data = NULL;
sk->sk_data_ready = conn->orig_data_ready;
sk->sk_state_change = conn->orig_state_change;
write_unlock_bh(&sk->sk_callback_lock);
sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
}
static int iscsi_target_do_login(struct iscsit_conn *, struct iscsi_login *);
static bool __iscsi_target_sk_check_close(struct sock *sk)
{
if (sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) {
pr_debug("__iscsi_target_sk_check_close: TCP_CLOSE_WAIT|TCP_CLOSE,"
"returning TRUE\n");
return true;
}
return false;
}
static bool iscsi_target_sk_check_close(struct iscsit_conn *conn)
{
bool state = false;
if (conn->sock) {
struct sock *sk = conn->sock->sk;
read_lock_bh(&sk->sk_callback_lock);
state = (__iscsi_target_sk_check_close(sk) ||
test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags));
read_unlock_bh(&sk->sk_callback_lock);
}
return state;
}
static bool iscsi_target_sk_check_flag(struct iscsit_conn *conn, unsigned int flag)
{
bool state = false;
if (conn->sock) {
struct sock *sk = conn->sock->sk;
read_lock_bh(&sk->sk_callback_lock);
state = test_bit(flag, &conn->login_flags);
read_unlock_bh(&sk->sk_callback_lock);
}
return state;
}
static bool iscsi_target_sk_check_and_clear(struct iscsit_conn *conn, unsigned int flag)
{
bool state = false;
if (conn->sock) {
struct sock *sk = conn->sock->sk;
write_lock_bh(&sk->sk_callback_lock);
state = (__iscsi_target_sk_check_close(sk) ||
test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags));
if (!state)
clear_bit(flag, &conn->login_flags);
write_unlock_bh(&sk->sk_callback_lock);
}
return state;
}
static void iscsi_target_login_drop(struct iscsit_conn *conn, struct iscsi_login *login)
{
bool zero_tsih = login->zero_tsih;
iscsi_remove_failed_auth_entry(conn);
iscsi_target_nego_release(conn);
iscsi_target_login_sess_out(conn, zero_tsih, true);
}
struct conn_timeout {
struct timer_list timer;
struct iscsit_conn *conn;
};
static void iscsi_target_login_timeout(struct timer_list *t)
{
struct conn_timeout *timeout = from_timer(timeout, t, timer);
struct iscsit_conn *conn = timeout->conn;
pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
if (conn->login_kworker) {
pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
conn->login_kworker->comm, conn->login_kworker->pid);
send_sig(SIGINT, conn->login_kworker, 1);
}
}
static void iscsi_target_do_login_rx(struct work_struct *work)
{
struct iscsit_conn *conn = container_of(work,
struct iscsit_conn, login_work.work);
struct iscsi_login *login = conn->login;
struct iscsi_np *np = login->np;
struct iscsi_portal_group *tpg = conn->tpg;
struct iscsi_tpg_np *tpg_np = conn->tpg_np;
struct conn_timeout timeout;
int rc, zero_tsih = login->zero_tsih;
bool state;
pr_debug("entering iscsi_target_do_login_rx, conn: %p, %s:%d\n",
conn, current->comm, current->pid);
/*
* If iscsi_target_do_login_rx() has been invoked by ->sk_data_ready()
* before initial PDU processing in iscsi_target_start_negotiation()
* has completed, go ahead and retry until it's cleared.
*
* Otherwise if the TCP connection drops while this is occuring,
* iscsi_target_start_negotiation() will detect the failure, call
* cancel_delayed_work_sync(&conn->login_work), and cleanup the
* remaining iscsi connection resources from iscsi_np process context.
*/
if (iscsi_target_sk_check_flag(conn, LOGIN_FLAGS_INITIAL_PDU)) {
schedule_delayed_work(&conn->login_work, msecs_to_jiffies(10));
return;
}
spin_lock(&tpg->tpg_state_lock);
state = (tpg->tpg_state == TPG_STATE_ACTIVE);
spin_unlock(&tpg->tpg_state_lock);
if (!state) {
pr_debug("iscsi_target_do_login_rx: tpg_state != TPG_STATE_ACTIVE\n");
goto err;
}
if (iscsi_target_sk_check_close(conn)) {
pr_debug("iscsi_target_do_login_rx, TCP state CLOSE\n");
goto err;
}
conn->login_kworker = current;
allow_signal(SIGINT);
timeout.conn = conn;
timer_setup_on_stack(&timeout.timer, iscsi_target_login_timeout, 0);
mod_timer(&timeout.timer, jiffies + TA_LOGIN_TIMEOUT * HZ);
pr_debug("Starting login timer for %s/%d\n", current->comm, current->pid);
rc = conn->conn_transport->iscsit_get_login_rx(conn, login);
del_timer_sync(&timeout.timer);
destroy_timer_on_stack(&timeout.timer);
flush_signals(current);
conn->login_kworker = NULL;
if (rc < 0)
goto err;
pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n",
conn, current->comm, current->pid);
/*
* LOGIN_FLAGS_READ_ACTIVE is cleared so that sk_data_ready
* could be triggered again after this.
*
* LOGIN_FLAGS_WRITE_ACTIVE is cleared after we successfully
* process a login PDU, so that sk_state_chage can do login
* cleanup as needed if the socket is closed. If a delayed work is
* ongoing (LOGIN_FLAGS_WRITE_ACTIVE or LOGIN_FLAGS_READ_ACTIVE),
* sk_state_change will leave the cleanup to the delayed work or
* it will schedule a delayed work to do cleanup.
*/
if (conn->sock) {
struct sock *sk = conn->sock->sk;
write_lock_bh(&sk->sk_callback_lock);
if (!test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags)) {
clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);
set_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags);
}
write_unlock_bh(&sk->sk_callback_lock);
}
rc = iscsi_target_do_login(conn, login);
if (rc < 0) {
goto err;
} else if (!rc) {
if (iscsi_target_sk_check_and_clear(conn,
LOGIN_FLAGS_WRITE_ACTIVE))
goto err;
} else if (rc == 1) {
cancel_delayed_work(&conn->login_work);
iscsi_target_nego_release(conn);
iscsi_post_login_handler(np, conn, zero_tsih);
iscsit_deaccess_np(np, tpg, tpg_np);
}
return;
err:
iscsi_target_restore_sock_callbacks(conn);
cancel_delayed_work(&conn->login_work);
iscsi_target_login_drop(conn, login);
iscsit_deaccess_np(np, tpg, tpg_np);
}
static void iscsi_target_sk_state_change(struct sock *sk)
{
struct iscsit_conn *conn;
void (*orig_state_change)(struct sock *);
bool state;
pr_debug("Entering iscsi_target_sk_state_change\n");
write_lock_bh(&sk->sk_callback_lock);
conn = sk->sk_user_data;
if (!conn) {
write_unlock_bh(&sk->sk_callback_lock);
return;
}
orig_state_change = conn->orig_state_change;
if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {
pr_debug("Got LOGIN_FLAGS_READY=0 sk_state_change conn: %p\n",
conn);
write_unlock_bh(&sk->sk_callback_lock);
orig_state_change(sk);
return;
}
state = __iscsi_target_sk_check_close(sk);
pr_debug("__iscsi_target_sk_close_change: state: %d\n", state);
if (test_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags) ||
test_bit(LOGIN_FLAGS_WRITE_ACTIVE, &conn->login_flags)) {
pr_debug("Got LOGIN_FLAGS_{READ|WRITE}_ACTIVE=1"
" sk_state_change conn: %p\n", conn);
if (state)
set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
write_unlock_bh(&sk->sk_callback_lock);
orig_state_change(sk);
return;
}
if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {
pr_debug("Got LOGIN_FLAGS_CLOSED=1 sk_state_change conn: %p\n",
conn);
write_unlock_bh(&sk->sk_callback_lock);
orig_state_change(sk);
return;
}
/*
* If the TCP connection has dropped, go ahead and set LOGIN_FLAGS_CLOSED,
* but only queue conn->login_work -> iscsi_target_do_login_rx()
* processing if LOGIN_FLAGS_INITIAL_PDU has already been cleared.
*
* When iscsi_target_do_login_rx() runs, iscsi_target_sk_check_close()
* will detect the dropped TCP connection from delayed workqueue context.
*
* If LOGIN_FLAGS_INITIAL_PDU is still set, which means the initial
* iscsi_target_start_negotiation() is running, iscsi_target_do_login()
* via iscsi_target_sk_check_close() or iscsi_target_start_negotiation()
* via iscsi_target_sk_check_and_clear() is responsible for detecting the
* dropped TCP connection in iscsi_np process context, and cleaning up
* the remaining iscsi connection resources.
*/
if (state) {
pr_debug("iscsi_target_sk_state_change got failed state\n");
set_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags);
state = test_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
write_unlock_bh(&sk->sk_callback_lock);
orig_state_change(sk);
if (!state)
schedule_delayed_work(&conn->login_work, 0);
return;
}
write_unlock_bh(&sk->sk_callback_lock);
orig_state_change(sk);
}
/*
* NOTE: We check for existing sessions or connections AFTER the initiator
* has been successfully authenticated in order to protect against faked
* ISID/TSIH combinations.
*/
static int iscsi_target_check_for_existing_instances(
struct iscsit_conn *conn,
struct iscsi_login *login)
{
if (login->checked_for_existing)
return 0;
login->checked_for_existing = 1;
if (!login->tsih)
return iscsi_check_for_session_reinstatement(conn);
else
return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
login->initial_exp_statsn);
}
static int iscsi_target_do_authentication(
struct iscsit_conn *conn,
struct iscsi_login *login)
{
int authret;
u32 payload_length;
struct iscsi_param *param;
struct iscsi_login_req *login_req;
struct iscsi_login_rsp *login_rsp;
login_req = (struct iscsi_login_req *) login->req;
login_rsp = (struct iscsi_login_rsp *) login->rsp;
payload_length = ntoh24(login_req->dlength);
param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
if (!param)
return -1;
authret = iscsi_handle_authentication(
conn,
login->req_buf,
login->rsp_buf,
payload_length,
&login->rsp_length,
param->value);
switch (authret) {
case 0:
pr_debug("Received OK response"
" from LIO Authentication, continuing.\n");
break;
case 1:
pr_debug("iSCSI security negotiation"
" completed successfully.\n");
login->auth_complete = 1;
if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
(login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
ISCSI_FLAG_LOGIN_TRANSIT);
login->current_stage = 1;
}
return iscsi_target_check_for_existing_instances(
conn, login);
case 2:
pr_err("Security negotiation"
" failed.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_AUTH_FAILED);
return -1;
default:
pr_err("Received unknown error %d from LIO"
" Authentication\n", authret);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_TARGET_ERROR);
return -1;
}
return 0;
}
bool iscsi_conn_auth_required(struct iscsit_conn *conn)
{
struct iscsi_node_acl *nacl;
struct se_node_acl *se_nacl;
if (conn->sess->sess_ops->SessionType) {
/*
* For SessionType=Discovery
*/
return conn->tpg->tpg_attrib.authentication;
}
/*
* For SessionType=Normal
*/
se_nacl = conn->sess->se_sess->se_node_acl;
if (!se_nacl) {
pr_debug("Unknown ACL is trying to connect\n");
return true;
}
if (se_nacl->dynamic_node_acl) {
pr_debug("Dynamic ACL %s is trying to connect\n",
se_nacl->initiatorname);
return conn->tpg->tpg_attrib.authentication;
}
pr_debug("Known ACL %s is trying to connect\n",
se_nacl->initiatorname);
nacl = to_iscsi_nacl(se_nacl);
if (nacl->node_attrib.authentication == NA_AUTHENTICATION_INHERITED)
return conn->tpg->tpg_attrib.authentication;
return nacl->node_attrib.authentication;
}
static int iscsi_target_handle_csg_zero(
struct iscsit_conn *conn,
struct iscsi_login *login)
{
int ret;
u32 payload_length;
struct iscsi_param *param;
struct iscsi_login_req *login_req;
struct iscsi_login_rsp *login_rsp;
login_req = (struct iscsi_login_req *) login->req;
login_rsp = (struct iscsi_login_rsp *) login->rsp;
payload_length = ntoh24(login_req->dlength);
param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
if (!param)
return -1;
ret = iscsi_decode_text_input(
PHASE_SECURITY|PHASE_DECLARATIVE,
SENDER_INITIATOR|SENDER_RECEIVER,
login->req_buf,
payload_length,
conn);
if (ret < 0)
return -1;
if (ret > 0) {
if (login->auth_complete) {
pr_err("Initiator has already been"
" successfully authenticated, but is still"
" sending %s keys.\n", param->value);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
goto do_auth;
} else if (!payload_length) {
pr_err("Initiator sent zero length security payload,"
" login failed\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_AUTH_FAILED);
return -1;
}
if (login->first_request)
if (iscsi_target_check_first_request(conn, login) < 0)
return -1;
ret = iscsi_encode_text_output(
PHASE_SECURITY|PHASE_DECLARATIVE,
SENDER_TARGET,
login->rsp_buf,
&login->rsp_length,
conn->param_list,
conn->tpg->tpg_attrib.login_keys_workaround);
if (ret < 0)
return -1;
if (!iscsi_check_negotiated_keys(conn->param_list)) {
bool auth_required = iscsi_conn_auth_required(conn);
if (auth_required) {
if (!strncmp(param->value, NONE, 4)) {
pr_err("Initiator sent AuthMethod=None but"
" Target is enforcing iSCSI Authentication,"
" login failed.\n");
iscsit_tx_login_rsp(conn,
ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_AUTH_FAILED);
return -1;
}
if (!login->auth_complete)
return 0;
if (strncmp(param->value, NONE, 4) &&
!login->auth_complete)
return 0;
}
if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
(login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
ISCSI_FLAG_LOGIN_TRANSIT;
login->current_stage = 1;
}
}
return 0;
do_auth:
return iscsi_target_do_authentication(conn, login);
}
static bool iscsi_conn_authenticated(struct iscsit_conn *conn,
struct iscsi_login *login)
{
if (!iscsi_conn_auth_required(conn))
return true;
if (login->auth_complete)
return true;
return false;
}
static int iscsi_target_handle_csg_one(struct iscsit_conn *conn, struct iscsi_login *login)
{
int ret;
u32 payload_length;
struct iscsi_login_req *login_req;
struct iscsi_login_rsp *login_rsp;
login_req = (struct iscsi_login_req *) login->req;
login_rsp = (struct iscsi_login_rsp *) login->rsp;
payload_length = ntoh24(login_req->dlength);
ret = iscsi_decode_text_input(
PHASE_OPERATIONAL|PHASE_DECLARATIVE,
SENDER_INITIATOR|SENDER_RECEIVER,
login->req_buf,
payload_length,
conn);
if (ret < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if (login->first_request)
if (iscsi_target_check_first_request(conn, login) < 0)
return -1;
if (iscsi_target_check_for_existing_instances(conn, login) < 0)
return -1;
ret = iscsi_encode_text_output(
PHASE_OPERATIONAL|PHASE_DECLARATIVE,
SENDER_TARGET,
login->rsp_buf,
&login->rsp_length,
conn->param_list,
conn->tpg->tpg_attrib.login_keys_workaround);
if (ret < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
return -1;
}
if (!iscsi_conn_authenticated(conn, login)) {
pr_err("Initiator is requesting CSG: 1, has not been"
" successfully authenticated, and the Target is"
" enforcing iSCSI Authentication, login failed.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_AUTH_FAILED);
return -1;
}
if (!iscsi_check_negotiated_keys(conn->param_list))
if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
(login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
ISCSI_FLAG_LOGIN_TRANSIT;
return 0;
}
/*
* RETURN VALUE:
*
* 1 = Login successful
* -1 = Login failed
* 0 = More PDU exchanges required
*/
static int iscsi_target_do_login(struct iscsit_conn *conn, struct iscsi_login *login)
{
int pdu_count = 0;
struct iscsi_login_req *login_req;
struct iscsi_login_rsp *login_rsp;
login_req = (struct iscsi_login_req *) login->req;
login_rsp = (struct iscsi_login_rsp *) login->rsp;
while (1) {
if (++pdu_count > MAX_LOGIN_PDUS) {
pr_err("MAX_LOGIN_PDUS count reached.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_TARGET_ERROR);
return -1;
}
switch (ISCSI_LOGIN_CURRENT_STAGE(login_req->flags)) {
case 0:
login_rsp->flags &= ~ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK;
if (iscsi_target_handle_csg_zero(conn, login) < 0)
return -1;
break;
case 1:
login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
if (iscsi_target_handle_csg_one(conn, login) < 0)
return -1;
if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
/*
* Check to make sure the TCP connection has not
* dropped asynchronously while session reinstatement
* was occuring in this kthread context, before
* transitioning to full feature phase operation.
*/
if (iscsi_target_sk_check_close(conn))
return -1;
login->tsih = conn->sess->tsih;
login->login_complete = 1;
iscsi_target_restore_sock_callbacks(conn);
if (iscsi_target_do_tx_login_io(conn,
login) < 0)
return -1;
return 1;
}
break;
default:
pr_err("Illegal CSG: %d received from"
" Initiator, protocol error.\n",
ISCSI_LOGIN_CURRENT_STAGE(login_req->flags));
break;
}
if (iscsi_target_do_tx_login_io(conn, login) < 0)
return -1;
if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
}
break;
}
return 0;
}
static void iscsi_initiatorname_tolower(
char *param_buf)
{
char *c;
u32 iqn_size = strlen(param_buf), i;
for (i = 0; i < iqn_size; i++) {
c = &param_buf[i];
if (!isupper(*c))
continue;
*c = tolower(*c);
}
}
/*
* Processes the first Login Request..
*/
int iscsi_target_locate_portal(
struct iscsi_np *np,
struct iscsit_conn *conn,
struct iscsi_login *login)
{
char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
struct iscsit_session *sess = conn->sess;
struct iscsi_tiqn *tiqn;
struct iscsi_tpg_np *tpg_np = NULL;
struct iscsi_login_req *login_req;
struct se_node_acl *se_nacl;
u32 payload_length, queue_depth = 0;
int sessiontype = 0, ret = 0, tag_num, tag_size;
INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
iscsi_target_set_sock_callbacks(conn);
login->np = np;
login_req = (struct iscsi_login_req *) login->req;
payload_length = ntoh24(login_req->dlength);
tmpbuf = kmemdup_nul(login->req_buf, payload_length, GFP_KERNEL);
if (!tmpbuf) {
pr_err("Unable to allocate memory for tmpbuf.\n");
return -1;
}
start = tmpbuf;
end = (start + payload_length);
/*
* Locate the initial keys expected from the Initiator node in
* the first login request in order to progress with the login phase.
*/
while (start < end) {
if (iscsi_extract_key_value(start, &key, &value) < 0) {
ret = -1;
goto out;
}
if (!strncmp(key, "InitiatorName", 13))
i_buf = value;
else if (!strncmp(key, "SessionType", 11))
s_buf = value;
else if (!strncmp(key, "TargetName", 10))
t_buf = value;
start += strlen(key) + strlen(value) + 2;
}
/*
* See 5.3. Login Phase.
*/
if (!i_buf) {
pr_err("InitiatorName key not received"
" in first login request.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_MISSING_FIELDS);
ret = -1;
goto out;
}
/*
* Convert the incoming InitiatorName to lowercase following
* RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
* are NOT case sensitive.
*/
iscsi_initiatorname_tolower(i_buf);
if (!s_buf) {
if (!login->leading_connection)
goto get_target;
pr_err("SessionType key not received"
" in first login request.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_MISSING_FIELDS);
ret = -1;
goto out;
}
/*
* Use default portal group for discovery sessions.
*/
sessiontype = strncmp(s_buf, DISCOVERY, 9);
if (!sessiontype) {
conn->tpg = iscsit_global->discovery_tpg;
if (!login->leading_connection)
goto get_target;
sess->sess_ops->SessionType = 1;
/*
* Setup crc32c modules from libcrypto
*/
if (iscsi_login_setup_crypto(conn) < 0) {
pr_err("iscsi_login_setup_crypto() failed\n");
ret = -1;
goto out;
}
/*
* Serialize access across the discovery struct iscsi_portal_group to
* process login attempt.
*/
if (iscsit_access_np(np, conn->tpg) < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
ret = -1;
goto out;
}
ret = 0;
goto alloc_tags;
}
get_target:
if (!t_buf) {
pr_err("TargetName key not received"
" in first login request while"
" SessionType=Normal.\n");
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_MISSING_FIELDS);
ret = -1;
goto out;
}
/*
* Locate Target IQN from Storage Node.
*/
tiqn = iscsit_get_tiqn_for_login(t_buf);
if (!tiqn) {
pr_err("Unable to locate Target IQN: %s in"
" Storage Node\n", t_buf);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
ret = -1;
goto out;
}
pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
/*
* Locate Target Portal Group from Storage Node.
*/
conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np);
if (!conn->tpg) {
pr_err("Unable to locate Target Portal Group"
" on %s\n", tiqn->tiqn);
iscsit_put_tiqn_for_login(tiqn);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
ret = -1;
goto out;
}
conn->tpg_np = tpg_np;
pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
/*
* Setup crc32c modules from libcrypto
*/
if (iscsi_login_setup_crypto(conn) < 0) {
pr_err("iscsi_login_setup_crypto() failed\n");
kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
iscsit_put_tiqn_for_login(tiqn);
conn->tpg = NULL;
ret = -1;
goto out;
}
/*
* Serialize access across the struct iscsi_portal_group to
* process login attempt.
*/
if (iscsit_access_np(np, conn->tpg) < 0) {
kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
iscsit_put_tiqn_for_login(tiqn);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
conn->tpg = NULL;
ret = -1;
goto out;
}
/*
* conn->sess->node_acl will be set when the referenced
* struct iscsit_session is located from received ISID+TSIH in
* iscsi_login_non_zero_tsih_s2().
*/
if (!login->leading_connection) {
ret = 0;
goto out;
}
/*
* This value is required in iscsi_login_zero_tsih_s2()
*/
sess->sess_ops->SessionType = 0;
/*
* Locate incoming Initiator IQN reference from Storage Node.
*/
sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
&conn->tpg->tpg_se_tpg, i_buf);
if (!sess->se_sess->se_node_acl) {
pr_err("iSCSI Initiator Node: %s is not authorized to"
" access iSCSI target portal group: %hu.\n",
i_buf, conn->tpg->tpgt);
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
ret = -1;
goto out;
}
se_nacl = sess->se_sess->se_node_acl;
queue_depth = se_nacl->queue_depth;
/*
* Setup pre-allocated tags based upon allowed per NodeACL CmdSN
* depth for non immediate commands, plus extra tags for immediate
* commands.
*
* Also enforce a ISCSIT_MIN_TAGS to prevent unnecessary contention
* in per-cpu-ida tag allocation logic + small queue_depth.
*/
alloc_tags:
tag_num = max_t(u32, ISCSIT_MIN_TAGS, queue_depth);
tag_num = (tag_num * 2) + ISCSIT_EXTRA_TAGS;
tag_size = sizeof(struct iscsit_cmd) + conn->conn_transport->priv_size;
ret = transport_alloc_session_tags(sess->se_sess, tag_num, tag_size);
if (ret < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
ISCSI_LOGIN_STATUS_NO_RESOURCES);
ret = -1;
}
out:
kfree(tmpbuf);
return ret;
}
int iscsi_target_start_negotiation(
struct iscsi_login *login,
struct iscsit_conn *conn)
{
int ret;
if (conn->sock) {
struct sock *sk = conn->sock->sk;
write_lock_bh(&sk->sk_callback_lock);
set_bit(LOGIN_FLAGS_READY, &conn->login_flags);
set_bit(LOGIN_FLAGS_INITIAL_PDU, &conn->login_flags);
write_unlock_bh(&sk->sk_callback_lock);
}
/*
* If iscsi_target_do_login returns zero to signal more PDU
* exchanges are required to complete the login, go ahead and
* clear LOGIN_FLAGS_INITIAL_PDU but only if the TCP connection
* is still active.
*
* Otherwise if TCP connection dropped asynchronously, go ahead
* and perform connection cleanup now.
*/
ret = iscsi_target_do_login(conn, login);
if (!ret && iscsi_target_sk_check_and_clear(conn, LOGIN_FLAGS_INITIAL_PDU))
ret = -1;
if (ret < 0) {
iscsi_target_restore_sock_callbacks(conn);
iscsi_remove_failed_auth_entry(conn);
}
if (ret != 0) {
cancel_delayed_work_sync(&conn->login_work);
iscsi_target_nego_release(conn);
}
return ret;
}
void iscsi_target_nego_release(struct iscsit_conn *conn)
{
struct iscsi_login *login = conn->conn_login;
if (!login)
return;
kfree(login->req_buf);
kfree(login->rsp_buf);
kfree(login);
conn->conn_login = NULL;
}