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0870d86eac
linux/fs/cifs/connect.c
Zhang Xiaoxu 1dcdf5f5b2 cifs: Fix connections leak when tlink setup failed 
If the tlink setup failed, lost to put the connections, then
the module refcnt leak since the cifsd kthread not exit.

Also leak the fscache info, and for next mount with fsc, it will
print the follow errors:
  CIFS: Cache volume key already in use (cifs,127.0.0.1:445,TEST)

Let's check the result of tlink setup, and do some cleanup.

Fixes: 56c762eb9b ("cifs: Refactor out cifs_mount()")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-11-11 11:59:30 -06:00

4743 lines
126 KiB
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// SPDX-License-Identifier: LGPL-2.1
/*
*
* Copyright (C) International Business Machines Corp., 2002,2011
* Author(s): Steve French (sfrench@us.ibm.com)
*
*/
#include <linux/fs.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/sched/mm.h>
#include <linux/sched/signal.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/pagevec.h>
#include <linux/freezer.h>
#include <linux/namei.h>
#include <linux/uuid.h>
#include <linux/uaccess.h>
#include <asm/processor.h>
#include <linux/inet.h>
#include <linux/module.h>
#include <keys/user-type.h>
#include <net/ipv6.h>
#include <linux/parser.h>
#include <linux/bvec.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "ntlmssp.h"
#include "nterr.h"
#include "rfc1002pdu.h"
#include "fscache.h"
#include "smb2proto.h"
#include "smbdirect.h"
#include "dns_resolve.h"
#ifdef CONFIG_CIFS_DFS_UPCALL
#include "dfs_cache.h"
#endif
#include "fs_context.h"
#include "cifs_swn.h"
extern mempool_t *cifs_req_poolp;
extern bool disable_legacy_dialects;
/* FIXME: should these be tunable? */
#define TLINK_ERROR_EXPIRE (1 * HZ)
#define TLINK_IDLE_EXPIRE (600 * HZ)
/* Drop the connection to not overload the server */
#define NUM_STATUS_IO_TIMEOUT 5
struct mount_ctx {
struct cifs_sb_info *cifs_sb;
struct smb3_fs_context *fs_ctx;
unsigned int xid;
struct TCP_Server_Info *server;
struct cifs_ses *ses;
struct cifs_tcon *tcon;
#ifdef CONFIG_CIFS_DFS_UPCALL
struct cifs_ses *root_ses;
uuid_t mount_id;
char *origin_fullpath, *leaf_fullpath;
#endif
};
static int ip_connect(struct TCP_Server_Info *server);
static int generic_ip_connect(struct TCP_Server_Info *server);
static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
static void cifs_prune_tlinks(struct work_struct *work);
/*
* Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
* get their ip addresses changed at some point.
*
* This should be called with server->srv_mutex held.
*/
static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
{
int rc;
int len;
char *unc, *ipaddr = NULL;
time64_t expiry, now;
unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
if (!server->hostname)
return -EINVAL;
/* if server hostname isn't populated, there's nothing to do here */
if (server->hostname[0] == '\0')
return 0;
len = strlen(server->hostname) + 3;
unc = kmalloc(len, GFP_KERNEL);
if (!unc) {
cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
return -ENOMEM;
}
scnprintf(unc, len, "\\\\%s", server->hostname);
rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
kfree(unc);
if (rc < 0) {
cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
__func__, server->hostname, rc);
goto requeue_resolve;
}
spin_lock(&server->srv_lock);
rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
strlen(ipaddr));
spin_unlock(&server->srv_lock);
kfree(ipaddr);
/* rc == 1 means success here */
if (rc) {
now = ktime_get_real_seconds();
if (expiry && expiry > now)
/*
* To make sure we don't use the cached entry, retry 1s
* after expiry.
*/
ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
}
rc = !rc ? -1 : 0;
requeue_resolve:
cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
__func__, ttl);
mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
return rc;
}
static void smb2_query_server_interfaces(struct work_struct *work)
{
int rc;
struct cifs_tcon *tcon = container_of(work,
struct cifs_tcon,
query_interfaces.work);
/*
* query server network interfaces, in case they change
*/
rc = SMB3_request_interfaces(0, tcon, false);
if (rc) {
cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
__func__, rc);
}
queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
(SMB_INTERFACE_POLL_INTERVAL * HZ));
}
static void cifs_resolve_server(struct work_struct *work)
{
int rc;
struct TCP_Server_Info *server = container_of(work,
struct TCP_Server_Info, resolve.work);
cifs_server_lock(server);
/*
* Resolve the hostname again to make sure that IP address is up-to-date.
*/
rc = reconn_set_ipaddr_from_hostname(server);
if (rc) {
cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
__func__, rc);
}
cifs_server_unlock(server);
}
/*
* Update the tcpStatus for the server.
* This is used to signal the cifsd thread to call cifs_reconnect
* ONLY cifsd thread should call cifs_reconnect. For any other
* thread, use this function
*
* @server: the tcp ses for which reconnect is needed
* @all_channels: if this needs to be done for all channels
*/
void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
bool all_channels)
{
struct TCP_Server_Info *pserver;
struct cifs_ses *ses;
int i;
/* If server is a channel, select the primary channel */
pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
spin_lock(&pserver->srv_lock);
if (!all_channels) {
pserver->tcpStatus = CifsNeedReconnect;
spin_unlock(&pserver->srv_lock);
return;
}
spin_unlock(&pserver->srv_lock);
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
spin_lock(&ses->chan_lock);
for (i = 0; i < ses->chan_count; i++) {
spin_lock(&ses->chans[i].server->srv_lock);
ses->chans[i].server->tcpStatus = CifsNeedReconnect;
spin_unlock(&ses->chans[i].server->srv_lock);
}
spin_unlock(&ses->chan_lock);
}
spin_unlock(&cifs_tcp_ses_lock);
}
/*
* Mark all sessions and tcons for reconnect.
* IMPORTANT: make sure that this gets called only from
* cifsd thread. For any other thread, use
* cifs_signal_cifsd_for_reconnect
*
* @server: the tcp ses for which reconnect is needed
* @server needs to be previously set to CifsNeedReconnect.
* @mark_smb_session: whether even sessions need to be marked
*/
void
cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
bool mark_smb_session)
{
struct TCP_Server_Info *pserver;
struct cifs_ses *ses, *nses;
struct cifs_tcon *tcon;
/*
* before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
* are not used until reconnected.
*/
cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
/* If server is a channel, select the primary channel */
pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
/* check if iface is still active */
if (!cifs_chan_is_iface_active(ses, server))
cifs_chan_update_iface(ses, server);
spin_lock(&ses->chan_lock);
if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
goto next_session;
if (mark_smb_session)
CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
else
cifs_chan_set_need_reconnect(ses, server);
/* If all channels need reconnect, then tcon needs reconnect */
if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
goto next_session;
ses->ses_status = SES_NEED_RECON;
list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
tcon->need_reconnect = true;
tcon->status = TID_NEED_RECON;
}
if (ses->tcon_ipc)
ses->tcon_ipc->need_reconnect = true;
next_session:
spin_unlock(&ses->chan_lock);
}
spin_unlock(&cifs_tcp_ses_lock);
}
static void
cifs_abort_connection(struct TCP_Server_Info *server)
{
struct mid_q_entry *mid, *nmid;
struct list_head retry_list;
server->maxBuf = 0;
server->max_read = 0;
/* do not want to be sending data on a socket we are freeing */
cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
cifs_server_lock(server);
if (server->ssocket) {
cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
server->ssocket->flags);
kernel_sock_shutdown(server->ssocket, SHUT_WR);
cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
server->ssocket->flags);
sock_release(server->ssocket);
server->ssocket = NULL;
}
server->sequence_number = 0;
server->session_estab = false;
kfree_sensitive(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
server->lstrp = jiffies;
/* mark submitted MIDs for retry and issue callback */
INIT_LIST_HEAD(&retry_list);
cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
spin_lock(&server->mid_lock);
list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
kref_get(&mid->refcount);
if (mid->mid_state == MID_REQUEST_SUBMITTED)
mid->mid_state = MID_RETRY_NEEDED;
list_move(&mid->qhead, &retry_list);
mid->mid_flags |= MID_DELETED;
}
spin_unlock(&server->mid_lock);
cifs_server_unlock(server);
cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
list_del_init(&mid->qhead);
mid->callback(mid);
release_mid(mid);
}
if (cifs_rdma_enabled(server)) {
cifs_server_lock(server);
smbd_destroy(server);
cifs_server_unlock(server);
}
}
static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
{
spin_lock(&server->srv_lock);
server->nr_targets = num_targets;
if (server->tcpStatus == CifsExiting) {
/* the demux thread will exit normally next time through the loop */
spin_unlock(&server->srv_lock);
wake_up(&server->response_q);
return false;
}
cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
trace_smb3_reconnect(server->CurrentMid, server->conn_id,
server->hostname);
server->tcpStatus = CifsNeedReconnect;
spin_unlock(&server->srv_lock);
return true;
}
/*
* cifs tcp session reconnection
*
* mark tcp session as reconnecting so temporarily locked
* mark all smb sessions as reconnecting for tcp session
* reconnect tcp session
* wake up waiters on reconnection? - (not needed currently)
*
* if mark_smb_session is passed as true, unconditionally mark
* the smb session (and tcon) for reconnect as well. This value
* doesn't really matter for non-multichannel scenario.
*
*/
static int __cifs_reconnect(struct TCP_Server_Info *server,
bool mark_smb_session)
{
int rc = 0;
if (!cifs_tcp_ses_needs_reconnect(server, 1))
return 0;
cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
cifs_abort_connection(server);
do {
try_to_freeze();
cifs_server_lock(server);
if (!cifs_swn_set_server_dstaddr(server)) {
/* resolve the hostname again to make sure that IP address is up-to-date */
rc = reconn_set_ipaddr_from_hostname(server);
cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
}
if (cifs_rdma_enabled(server))
rc = smbd_reconnect(server);
else
rc = generic_ip_connect(server);
if (rc) {
cifs_server_unlock(server);
cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
msleep(3000);
} else {
atomic_inc(&tcpSesReconnectCount);
set_credits(server, 1);
spin_lock(&server->srv_lock);
if (server->tcpStatus != CifsExiting)
server->tcpStatus = CifsNeedNegotiate;
spin_unlock(&server->srv_lock);
cifs_swn_reset_server_dstaddr(server);
cifs_server_unlock(server);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
}
} while (server->tcpStatus == CifsNeedReconnect);
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsNeedNegotiate)
mod_delayed_work(cifsiod_wq, &server->echo, 0);
spin_unlock(&server->srv_lock);
wake_up(&server->response_q);
return rc;
}
#ifdef CONFIG_CIFS_DFS_UPCALL
static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
{
int rc;
char *hostname;
if (!cifs_swn_set_server_dstaddr(server)) {
if (server->hostname != target) {
hostname = extract_hostname(target);
if (!IS_ERR(hostname)) {
kfree(server->hostname);
server->hostname = hostname;
} else {
cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
__func__, PTR_ERR(hostname));
cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
server->hostname);
}
}
/* resolve the hostname again to make sure that IP address is up-to-date. */
rc = reconn_set_ipaddr_from_hostname(server);
cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
}
/* Reconnect the socket */
if (cifs_rdma_enabled(server))
rc = smbd_reconnect(server);
else
rc = generic_ip_connect(server);
return rc;
}
static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
struct dfs_cache_tgt_iterator **target_hint)
{
int rc;
struct dfs_cache_tgt_iterator *tit;
*target_hint = NULL;
/* If dfs target list is empty, then reconnect to last server */
tit = dfs_cache_get_tgt_iterator(tl);
if (!tit)
return __reconnect_target_unlocked(server, server->hostname);
/* Otherwise, try every dfs target in @tl */
for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
if (!rc) {
*target_hint = tit;
break;
}
}
return rc;
}
static int reconnect_dfs_server(struct TCP_Server_Info *server)
{
int rc = 0;
const char *refpath = server->current_fullpath + 1;
struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
struct dfs_cache_tgt_iterator *target_hint = NULL;
int num_targets = 0;
/*
* Determine the number of dfs targets the referral path in @cifs_sb resolves to.
*
* smb2_reconnect() needs to know how long it should wait based upon the number of dfs
* targets (server->nr_targets). It's also possible that the cached referral was cleared
* through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
* refreshing the referral, so, in this case, default it to 1.
*/
if (!dfs_cache_noreq_find(refpath, NULL, &tl))
num_targets = dfs_cache_get_nr_tgts(&tl);
if (!num_targets)
num_targets = 1;
if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
return 0;
/*
* Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
* different server or share during failover. It could be improved by adding some logic to
* only do that in case it connects to a different server or share, though.
*/
cifs_mark_tcp_ses_conns_for_reconnect(server, true);
cifs_abort_connection(server);
do {
try_to_freeze();
cifs_server_lock(server);
rc = reconnect_target_unlocked(server, &tl, &target_hint);
if (rc) {
/* Failed to reconnect socket */
cifs_server_unlock(server);
cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
msleep(3000);
continue;
}
/*
* Socket was created. Update tcp session status to CifsNeedNegotiate so that a
* process waiting for reconnect will know it needs to re-establish session and tcon
* through the reconnected target server.
*/
atomic_inc(&tcpSesReconnectCount);
set_credits(server, 1);
spin_lock(&server->srv_lock);
if (server->tcpStatus != CifsExiting)
server->tcpStatus = CifsNeedNegotiate;
spin_unlock(&server->srv_lock);
cifs_swn_reset_server_dstaddr(server);
cifs_server_unlock(server);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
} while (server->tcpStatus == CifsNeedReconnect);
if (target_hint)
dfs_cache_noreq_update_tgthint(refpath, target_hint);
dfs_cache_free_tgts(&tl);
/* Need to set up echo worker again once connection has been established */
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsNeedNegotiate)
mod_delayed_work(cifsiod_wq, &server->echo, 0);
spin_unlock(&server->srv_lock);
wake_up(&server->response_q);
return rc;
}
int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
{
/* If tcp session is not an dfs connection, then reconnect to last target server */
spin_lock(&server->srv_lock);
if (!server->is_dfs_conn) {
spin_unlock(&server->srv_lock);
return __cifs_reconnect(server, mark_smb_session);
}
spin_unlock(&server->srv_lock);
mutex_lock(&server->refpath_lock);
if (!server->origin_fullpath || !server->leaf_fullpath) {
mutex_unlock(&server->refpath_lock);
return __cifs_reconnect(server, mark_smb_session);
}
mutex_unlock(&server->refpath_lock);
return reconnect_dfs_server(server);
}
#else
int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
{
return __cifs_reconnect(server, mark_smb_session);
}
#endif
static void
cifs_echo_request(struct work_struct *work)
{
int rc;
struct TCP_Server_Info *server = container_of(work,
struct TCP_Server_Info, echo.work);
/*
* We cannot send an echo if it is disabled.
* Also, no need to ping if we got a response recently.
*/
if (server->tcpStatus == CifsNeedReconnect ||
server->tcpStatus == CifsExiting ||
server->tcpStatus == CifsNew ||
(server->ops->can_echo && !server->ops->can_echo(server)) ||
time_before(jiffies, server->lstrp + server->echo_interval - HZ))
goto requeue_echo;
rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
if (rc)
cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
server->hostname);
/* Check witness registrations */
cifs_swn_check();
requeue_echo:
queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
}
static bool
allocate_buffers(struct TCP_Server_Info *server)
{
if (!server->bigbuf) {
server->bigbuf = (char *)cifs_buf_get();
if (!server->bigbuf) {
cifs_server_dbg(VFS, "No memory for large SMB response\n");
msleep(3000);
/* retry will check if exiting */
return false;
}
} else if (server->large_buf) {
/* we are reusing a dirty large buf, clear its start */
memset(server->bigbuf, 0, HEADER_SIZE(server));
}
if (!server->smallbuf) {
server->smallbuf = (char *)cifs_small_buf_get();
if (!server->smallbuf) {
cifs_server_dbg(VFS, "No memory for SMB response\n");
msleep(1000);
/* retry will check if exiting */
return false;
}
/* beginning of smb buffer is cleared in our buf_get */
} else {
/* if existing small buf clear beginning */
memset(server->smallbuf, 0, HEADER_SIZE(server));
}
return true;
}
static bool
server_unresponsive(struct TCP_Server_Info *server)
{
/*
* We need to wait 3 echo intervals to make sure we handle such
* situations right:
* 1s client sends a normal SMB request
* 2s client gets a response
* 30s echo workqueue job pops, and decides we got a response recently
* and don't need to send another
* ...
* 65s kernel_recvmsg times out, and we see that we haven't gotten
* a response in >60s.
*/
spin_lock(&server->srv_lock);
if ((server->tcpStatus == CifsGood ||
server->tcpStatus == CifsNeedNegotiate) &&
(!server->ops->can_echo || server->ops->can_echo(server)) &&
time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
spin_unlock(&server->srv_lock);
cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
(3 * server->echo_interval) / HZ);
cifs_reconnect(server, false);
return true;
}
spin_unlock(&server->srv_lock);
return false;
}
static inline bool
zero_credits(struct TCP_Server_Info *server)
{
int val;
spin_lock(&server->req_lock);
val = server->credits + server->echo_credits + server->oplock_credits;
if (server->in_flight == 0 && val == 0) {
spin_unlock(&server->req_lock);
return true;
}
spin_unlock(&server->req_lock);
return false;
}
static int
cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
{
int length = 0;
int total_read;
for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
try_to_freeze();
/* reconnect if no credits and no requests in flight */
if (zero_credits(server)) {
cifs_reconnect(server, false);
return -ECONNABORTED;
}
if (server_unresponsive(server))
return -ECONNABORTED;
if (cifs_rdma_enabled(server) && server->smbd_conn)
length = smbd_recv(server->smbd_conn, smb_msg);
else
length = sock_recvmsg(server->ssocket, smb_msg, 0);
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsExiting) {
spin_unlock(&server->srv_lock);
return -ESHUTDOWN;
}
if (server->tcpStatus == CifsNeedReconnect) {
spin_unlock(&server->srv_lock);
cifs_reconnect(server, false);
return -ECONNABORTED;
}
spin_unlock(&server->srv_lock);
if (length == -ERESTARTSYS ||
length == -EAGAIN ||
length == -EINTR) {
/*
* Minimum sleep to prevent looping, allowing socket
* to clear and app threads to set tcpStatus
* CifsNeedReconnect if server hung.
*/
usleep_range(1000, 2000);
length = 0;
continue;
}
if (length <= 0) {
cifs_dbg(FYI, "Received no data or error: %d\n", length);
cifs_reconnect(server, false);
return -ECONNABORTED;
}
}
return total_read;
}
int
cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
unsigned int to_read)
{
struct msghdr smb_msg = {};
struct kvec iov = {.iov_base = buf, .iov_len = to_read};
iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
return cifs_readv_from_socket(server, &smb_msg);
}
ssize_t
cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
{
struct msghdr smb_msg = {};
/*
* iov_iter_discard already sets smb_msg.type and count and iov_offset
* and cifs_readv_from_socket sets msg_control and msg_controllen
* so little to initialize in struct msghdr
*/
iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
return cifs_readv_from_socket(server, &smb_msg);
}
int
cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
unsigned int page_offset, unsigned int to_read)
{
struct msghdr smb_msg = {};
struct bio_vec bv = {
.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
return cifs_readv_from_socket(server, &smb_msg);
}
static bool
is_smb_response(struct TCP_Server_Info *server, unsigned char type)
{
/*
* The first byte big endian of the length field,
* is actually not part of the length but the type
* with the most common, zero, as regular data.
*/
switch (type) {
case RFC1002_SESSION_MESSAGE:
/* Regular SMB response */
return true;
case RFC1002_SESSION_KEEP_ALIVE:
cifs_dbg(FYI, "RFC 1002 session keep alive\n");
break;
case RFC1002_POSITIVE_SESSION_RESPONSE:
cifs_dbg(FYI, "RFC 1002 positive session response\n");
break;
case RFC1002_NEGATIVE_SESSION_RESPONSE:
/*
* We get this from Windows 98 instead of an error on
* SMB negprot response.
*/
cifs_dbg(FYI, "RFC 1002 negative session response\n");
/* give server a second to clean up */
msleep(1000);
/*
* Always try 445 first on reconnect since we get NACK
* on some if we ever connected to port 139 (the NACK
* is since we do not begin with RFC1001 session
* initialize frame).
*/
cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
cifs_reconnect(server, true);
break;
default:
cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
cifs_reconnect(server, true);
}
return false;
}
void
dequeue_mid(struct mid_q_entry *mid, bool malformed)
{
#ifdef CONFIG_CIFS_STATS2
mid->when_received = jiffies;
#endif
spin_lock(&mid->server->mid_lock);
if (!malformed)
mid->mid_state = MID_RESPONSE_RECEIVED;
else
mid->mid_state = MID_RESPONSE_MALFORMED;
/*
* Trying to handle/dequeue a mid after the send_recv()
* function has finished processing it is a bug.
*/
if (mid->mid_flags & MID_DELETED) {
spin_unlock(&mid->server->mid_lock);
pr_warn_once("trying to dequeue a deleted mid\n");
} else {
list_del_init(&mid->qhead);
mid->mid_flags |= MID_DELETED;
spin_unlock(&mid->server->mid_lock);
}
}
static unsigned int
smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
{
struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
/*
* SMB1 does not use credits.
*/
if (is_smb1(server))
return 0;
return le16_to_cpu(shdr->CreditRequest);
}
static void
handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
char *buf, int malformed)
{
if (server->ops->check_trans2 &&
server->ops->check_trans2(mid, server, buf, malformed))
return;
mid->credits_received = smb2_get_credits_from_hdr(buf, server);
mid->resp_buf = buf;
mid->large_buf = server->large_buf;
/* Was previous buf put in mpx struct for multi-rsp? */
if (!mid->multiRsp) {
/* smb buffer will be freed by user thread */
if (server->large_buf)
server->bigbuf = NULL;
else
server->smallbuf = NULL;
}
dequeue_mid(mid, malformed);
}
int
cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
{
bool srv_sign_required = server->sec_mode & server->vals->signing_required;
bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
bool mnt_sign_enabled;
/*
* Is signing required by mnt options? If not then check
* global_secflags to see if it is there.
*/
if (!mnt_sign_required)
mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
CIFSSEC_MUST_SIGN);
/*
* If signing is required then it's automatically enabled too,
* otherwise, check to see if the secflags allow it.
*/
mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
(global_secflags & CIFSSEC_MAY_SIGN);
/* If server requires signing, does client allow it? */
if (srv_sign_required) {
if (!mnt_sign_enabled) {
cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
return -EOPNOTSUPP;
}
server->sign = true;
}
/* If client requires signing, does server allow it? */
if (mnt_sign_required) {
if (!srv_sign_enabled) {
cifs_dbg(VFS, "Server does not support signing!\n");
return -EOPNOTSUPP;
}
server->sign = true;
}
if (cifs_rdma_enabled(server) && server->sign)
cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
return 0;
}
static void clean_demultiplex_info(struct TCP_Server_Info *server)
{
int length;
/* take it off the list, if it's not already */
spin_lock(&server->srv_lock);
list_del_init(&server->tcp_ses_list);
spin_unlock(&server->srv_lock);
cancel_delayed_work_sync(&server->echo);
cancel_delayed_work_sync(&server->resolve);
spin_lock(&server->srv_lock);
server->tcpStatus = CifsExiting;
spin_unlock(&server->srv_lock);
wake_up_all(&server->response_q);
/* check if we have blocked requests that need to free */
spin_lock(&server->req_lock);
if (server->credits <= 0)
server->credits = 1;
spin_unlock(&server->req_lock);
/*
* Although there should not be any requests blocked on this queue it
* can not hurt to be paranoid and try to wake up requests that may
* haven been blocked when more than 50 at time were on the wire to the
* same server - they now will see the session is in exit state and get
* out of SendReceive.
*/
wake_up_all(&server->request_q);
/* give those requests time to exit */
msleep(125);
if (cifs_rdma_enabled(server))
smbd_destroy(server);
if (server->ssocket) {
sock_release(server->ssocket);
server->ssocket = NULL;
}
if (!list_empty(&server->pending_mid_q)) {
struct list_head dispose_list;
struct mid_q_entry *mid_entry;
struct list_head *tmp, *tmp2;
INIT_LIST_HEAD(&dispose_list);
spin_lock(&server->mid_lock);
list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
kref_get(&mid_entry->refcount);
mid_entry->mid_state = MID_SHUTDOWN;
list_move(&mid_entry->qhead, &dispose_list);
mid_entry->mid_flags |= MID_DELETED;
}
spin_unlock(&server->mid_lock);
/* now walk dispose list and issue callbacks */
list_for_each_safe(tmp, tmp2, &dispose_list) {
mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
list_del_init(&mid_entry->qhead);
mid_entry->callback(mid_entry);
release_mid(mid_entry);
}
/* 1/8th of sec is more than enough time for them to exit */
msleep(125);
}
if (!list_empty(&server->pending_mid_q)) {
/*
* mpx threads have not exited yet give them at least the smb
* send timeout time for long ops.
*
* Due to delays on oplock break requests, we need to wait at
* least 45 seconds before giving up on a request getting a
* response and going ahead and killing cifsd.
*/
cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
msleep(46000);
/*
* If threads still have not exited they are probably never
* coming home not much else we can do but free the memory.
*/
}
#ifdef CONFIG_CIFS_DFS_UPCALL
kfree(server->origin_fullpath);
kfree(server->leaf_fullpath);
#endif
kfree(server);
length = atomic_dec_return(&tcpSesAllocCount);
if (length > 0)
mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
}
static int
standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
int length;
char *buf = server->smallbuf;
unsigned int pdu_length = server->pdu_size;
/* make sure this will fit in a large buffer */
if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
HEADER_PREAMBLE_SIZE(server)) {
cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
cifs_reconnect(server, true);
return -ECONNABORTED;
}
/* switch to large buffer if too big for a small one */
if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
server->large_buf = true;
memcpy(server->bigbuf, buf, server->total_read);
buf = server->bigbuf;
}
/* now read the rest */
length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
pdu_length - MID_HEADER_SIZE(server));
if (length < 0)
return length;
server->total_read += length;
dump_smb(buf, server->total_read);
return cifs_handle_standard(server, mid);
}
int
cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
int rc;
/*
* We know that we received enough to get to the MID as we
* checked the pdu_length earlier. Now check to see
* if the rest of the header is OK.
*
* 48 bytes is enough to display the header and a little bit
* into the payload for debugging purposes.
*/
rc = server->ops->check_message(buf, server->total_read, server);
if (rc)
cifs_dump_mem("Bad SMB: ", buf,
min_t(unsigned int, server->total_read, 48));
if (server->ops->is_session_expired &&
server->ops->is_session_expired(buf)) {
cifs_reconnect(server, true);
return -1;
}
if (server->ops->is_status_pending &&
server->ops->is_status_pending(buf, server))
return -1;
if (!mid)
return rc;
handle_mid(mid, server, buf, rc);
return 0;
}
static void
smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
{
struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
int scredits, in_flight;
/*
* SMB1 does not use credits.
*/
if (is_smb1(server))
return;
if (shdr->CreditRequest) {
spin_lock(&server->req_lock);
server->credits += le16_to_cpu(shdr->CreditRequest);
scredits = server->credits;
in_flight = server->in_flight;
spin_unlock(&server->req_lock);
wake_up(&server->request_q);
trace_smb3_hdr_credits(server->CurrentMid,
server->conn_id, server->hostname, scredits,
le16_to_cpu(shdr->CreditRequest), in_flight);
cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
__func__, le16_to_cpu(shdr->CreditRequest),
scredits);
}
}
static int
cifs_demultiplex_thread(void *p)
{
int i, num_mids, length;
struct TCP_Server_Info *server = p;
unsigned int pdu_length;
unsigned int next_offset;
char *buf = NULL;
struct task_struct *task_to_wake = NULL;
struct mid_q_entry *mids[MAX_COMPOUND];
char *bufs[MAX_COMPOUND];
unsigned int noreclaim_flag, num_io_timeout = 0;
noreclaim_flag = memalloc_noreclaim_save();
cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
length = atomic_inc_return(&tcpSesAllocCount);
if (length > 1)
mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
set_freezable();
allow_kernel_signal(SIGKILL);
while (server->tcpStatus != CifsExiting) {
if (try_to_freeze())
continue;
if (!allocate_buffers(server))
continue;
server->large_buf = false;
buf = server->smallbuf;
pdu_length = 4; /* enough to get RFC1001 header */
length = cifs_read_from_socket(server, buf, pdu_length);
if (length < 0)
continue;
if (is_smb1(server))
server->total_read = length;
else
server->total_read = 0;
/*
* The right amount was read from socket - 4 bytes,
* so we can now interpret the length field.
*/
pdu_length = get_rfc1002_length(buf);
cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
if (!is_smb_response(server, buf[0]))
continue;
next_pdu:
server->pdu_size = pdu_length;
/* make sure we have enough to get to the MID */
if (server->pdu_size < MID_HEADER_SIZE(server)) {
cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
server->pdu_size);
cifs_reconnect(server, true);
continue;
}
/* read down to the MID */
length = cifs_read_from_socket(server,
buf + HEADER_PREAMBLE_SIZE(server),
MID_HEADER_SIZE(server));
if (length < 0)
continue;
server->total_read += length;
if (server->ops->next_header) {
next_offset = server->ops->next_header(buf);
if (next_offset)
server->pdu_size = next_offset;
}
memset(mids, 0, sizeof(mids));
memset(bufs, 0, sizeof(bufs));
num_mids = 0;
if (server->ops->is_transform_hdr &&
server->ops->receive_transform &&
server->ops->is_transform_hdr(buf)) {
length = server->ops->receive_transform(server,
mids,
bufs,
&num_mids);
} else {
mids[0] = server->ops->find_mid(server, buf);
bufs[0] = buf;
num_mids = 1;
if (!mids[0] || !mids[0]->receive)
length = standard_receive3(server, mids[0]);
else
length = mids[0]->receive(server, mids[0]);
}
if (length < 0) {
for (i = 0; i < num_mids; i++)
if (mids[i])
release_mid(mids[i]);
continue;
}
if (server->ops->is_status_io_timeout &&
server->ops->is_status_io_timeout(buf)) {
num_io_timeout++;
if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
cifs_reconnect(server, false);
num_io_timeout = 0;
continue;
}
}
server->lstrp = jiffies;
for (i = 0; i < num_mids; i++) {
if (mids[i] != NULL) {
mids[i]->resp_buf_size = server->pdu_size;
if (bufs[i] && server->ops->is_network_name_deleted)
server->ops->is_network_name_deleted(bufs[i],
server);
if (!mids[i]->multiRsp || mids[i]->multiEnd)
mids[i]->callback(mids[i]);
release_mid(mids[i]);
} else if (server->ops->is_oplock_break &&
server->ops->is_oplock_break(bufs[i],
server)) {
smb2_add_credits_from_hdr(bufs[i], server);
cifs_dbg(FYI, "Received oplock break\n");
} else {
cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
atomic_read(&mid_count));
cifs_dump_mem("Received Data is: ", bufs[i],
HEADER_SIZE(server));
smb2_add_credits_from_hdr(bufs[i], server);
#ifdef CONFIG_CIFS_DEBUG2
if (server->ops->dump_detail)
server->ops->dump_detail(bufs[i],
server);
cifs_dump_mids(server);
#endif /* CIFS_DEBUG2 */
}
}
if (pdu_length > server->pdu_size) {
if (!allocate_buffers(server))
continue;
pdu_length -= server->pdu_size;
server->total_read = 0;
server->large_buf = false;
buf = server->smallbuf;
goto next_pdu;
}
} /* end while !EXITING */
/* buffer usually freed in free_mid - need to free it here on exit */
cifs_buf_release(server->bigbuf);
if (server->smallbuf) /* no sense logging a debug message if NULL */
cifs_small_buf_release(server->smallbuf);
task_to_wake = xchg(&server->tsk, NULL);
clean_demultiplex_info(server);
/* if server->tsk was NULL then wait for a signal before exiting */
if (!task_to_wake) {
set_current_state(TASK_INTERRUPTIBLE);
while (!signal_pending(current)) {
schedule();
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
}
memalloc_noreclaim_restore(noreclaim_flag);
module_put_and_kthread_exit(0);
}
/*
* Returns true if srcaddr isn't specified and rhs isn't specified, or
* if srcaddr is specified and matches the IP address of the rhs argument
*/
bool
cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
{
switch (srcaddr->sa_family) {
case AF_UNSPEC:
return (rhs->sa_family == AF_UNSPEC);
case AF_INET: {
struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
}
case AF_INET6: {
struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
}
default:
WARN_ON(1);
return false; /* don't expect to be here */
}
}
/*
* If no port is specified in addr structure, we try to match with 445 port
* and if it fails - with 139 ports. It should be called only if address
* families of server and addr are equal.
*/
static bool
match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
{
__be16 port, *sport;
/* SMBDirect manages its own ports, don't match it here */
if (server->rdma)
return true;
switch (addr->sa_family) {
case AF_INET:
sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
port = ((struct sockaddr_in *) addr)->sin_port;
break;
case AF_INET6:
sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
port = ((struct sockaddr_in6 *) addr)->sin6_port;
break;
default:
WARN_ON(1);
return false;
}
if (!port) {
port = htons(CIFS_PORT);
if (port == *sport)
return true;
port = htons(RFC1001_PORT);
}
return port == *sport;
}
static bool
match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
struct sockaddr *srcaddr)
{
switch (addr->sa_family) {
case AF_INET: {
struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
struct sockaddr_in *srv_addr4 =
(struct sockaddr_in *)&server->dstaddr;
if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
return false;
break;
}
case AF_INET6: {
struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
struct sockaddr_in6 *srv_addr6 =
(struct sockaddr_in6 *)&server->dstaddr;
if (!ipv6_addr_equal(&addr6->sin6_addr,
&srv_addr6->sin6_addr))
return false;
if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
return false;
break;
}
default:
WARN_ON(1);
return false; /* don't expect to be here */
}
if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
return false;
return true;
}
static bool
match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
{
/*
* The select_sectype function should either return the ctx->sectype
* that was specified, or "Unspecified" if that sectype was not
* compatible with the given NEGOTIATE request.
*/
if (server->ops->select_sectype(server, ctx->sectype)
== Unspecified)
return false;
/*
* Now check if signing mode is acceptable. No need to check
* global_secflags at this point since if MUST_SIGN is set then
* the server->sign had better be too.
*/
if (ctx->sign && !server->sign)
return false;
return true;
}
/* this function must be called with srv_lock held */
static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
{
struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
if (ctx->nosharesock)
return 0;
/* this server does not share socket */
if (server->nosharesock)
return 0;
/* If multidialect negotiation see if existing sessions match one */
if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
if (server->vals->protocol_id < SMB30_PROT_ID)
return 0;
} else if (strcmp(ctx->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0) {
if (server->vals->protocol_id < SMB21_PROT_ID)
return 0;
} else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
return 0;
if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
return 0;
if (strcasecmp(server->hostname, ctx->server_hostname))
return 0;
if (!match_address(server, addr,
(struct sockaddr *)&ctx->srcaddr))
return 0;
if (!match_port(server, addr))
return 0;
if (!match_security(server, ctx))
return 0;
if (server->echo_interval != ctx->echo_interval * HZ)
return 0;
if (server->rdma != ctx->rdma)
return 0;
if (server->ignore_signature != ctx->ignore_signature)
return 0;
if (server->min_offload != ctx->min_offload)
return 0;
return 1;
}
struct TCP_Server_Info *
cifs_find_tcp_session(struct smb3_fs_context *ctx)
{
struct TCP_Server_Info *server;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
spin_lock(&server->srv_lock);
#ifdef CONFIG_CIFS_DFS_UPCALL
/*
* DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
* DFS connections to do failover properly, so avoid sharing them with regular
* shares or even links that may connect to same server but having completely
* different failover targets.
*/
if (server->is_dfs_conn) {
spin_unlock(&server->srv_lock);
continue;
}
#endif
/*
* Skip ses channels since they're only handled in lower layers
* (e.g. cifs_send_recv).
*/
if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) {
spin_unlock(&server->srv_lock);
continue;
}
spin_unlock(&server->srv_lock);
++server->srv_count;
spin_unlock(&cifs_tcp_ses_lock);
cifs_dbg(FYI, "Existing tcp session with server found\n");
return server;
}
spin_unlock(&cifs_tcp_ses_lock);
return NULL;
}
void
cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
{
struct task_struct *task;
spin_lock(&cifs_tcp_ses_lock);
if (--server->srv_count > 0) {
spin_unlock(&cifs_tcp_ses_lock);
return;
}
/* srv_count can never go negative */
WARN_ON(server->srv_count < 0);
put_net(cifs_net_ns(server));
list_del_init(&server->tcp_ses_list);
spin_unlock(&cifs_tcp_ses_lock);
/* For secondary channels, we pick up ref-count on the primary server */
if (CIFS_SERVER_IS_CHAN(server))
cifs_put_tcp_session(server->primary_server, from_reconnect);
cancel_delayed_work_sync(&server->echo);
cancel_delayed_work_sync(&server->resolve);
if (from_reconnect)
/*
* Avoid deadlock here: reconnect work calls
* cifs_put_tcp_session() at its end. Need to be sure
* that reconnect work does nothing with server pointer after
* that step.
*/
cancel_delayed_work(&server->reconnect);
else
cancel_delayed_work_sync(&server->reconnect);
spin_lock(&server->srv_lock);
server->tcpStatus = CifsExiting;
spin_unlock(&server->srv_lock);
cifs_crypto_secmech_release(server);
kfree_sensitive(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
kfree(server->hostname);
server->hostname = NULL;
task = xchg(&server->tsk, NULL);
if (task)
send_sig(SIGKILL, task, 1);
}
struct TCP_Server_Info *
cifs_get_tcp_session(struct smb3_fs_context *ctx,
struct TCP_Server_Info *primary_server)
{
struct TCP_Server_Info *tcp_ses = NULL;
int rc;
cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
/* see if we already have a matching tcp_ses */
tcp_ses = cifs_find_tcp_session(ctx);
if (tcp_ses)
return tcp_ses;
tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
if (!tcp_ses) {
rc = -ENOMEM;
goto out_err;
}
tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
if (!tcp_ses->hostname) {
rc = -ENOMEM;
goto out_err;
}
if (ctx->nosharesock)
tcp_ses->nosharesock = true;
tcp_ses->ops = ctx->ops;
tcp_ses->vals = ctx->vals;
cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
tcp_ses->noblockcnt = ctx->rootfs;
tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
tcp_ses->noautotune = ctx->noautotune;
tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
tcp_ses->rdma = ctx->rdma;
tcp_ses->in_flight = 0;
tcp_ses->max_in_flight = 0;
tcp_ses->credits = 1;
if (primary_server) {
spin_lock(&cifs_tcp_ses_lock);
++primary_server->srv_count;
spin_unlock(&cifs_tcp_ses_lock);
tcp_ses->primary_server = primary_server;
}
init_waitqueue_head(&tcp_ses->response_q);
init_waitqueue_head(&tcp_ses->request_q);
INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
mutex_init(&tcp_ses->_srv_mutex);
memcpy(tcp_ses->workstation_RFC1001_name,
ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
memcpy(tcp_ses->server_RFC1001_name,
ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
tcp_ses->session_estab = false;
tcp_ses->sequence_number = 0;
tcp_ses->reconnect_instance = 1;
tcp_ses->lstrp = jiffies;
tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
spin_lock_init(&tcp_ses->req_lock);
spin_lock_init(&tcp_ses->srv_lock);
spin_lock_init(&tcp_ses->mid_lock);
INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
mutex_init(&tcp_ses->reconnect_mutex);
#ifdef CONFIG_CIFS_DFS_UPCALL
mutex_init(&tcp_ses->refpath_lock);
#endif
memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
sizeof(tcp_ses->srcaddr));
memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
sizeof(tcp_ses->dstaddr));
if (ctx->use_client_guid)
memcpy(tcp_ses->client_guid, ctx->client_guid,
SMB2_CLIENT_GUID_SIZE);
else
generate_random_uuid(tcp_ses->client_guid);
/*
* at this point we are the only ones with the pointer
* to the struct since the kernel thread not created yet
* no need to spinlock this init of tcpStatus or srv_count
*/
tcp_ses->tcpStatus = CifsNew;
++tcp_ses->srv_count;
if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
tcp_ses->echo_interval = ctx->echo_interval * HZ;
else
tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
if (tcp_ses->rdma) {
#ifndef CONFIG_CIFS_SMB_DIRECT
cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
rc = -ENOENT;
goto out_err_crypto_release;
#endif
tcp_ses->smbd_conn = smbd_get_connection(
tcp_ses, (struct sockaddr *)&ctx->dstaddr);
if (tcp_ses->smbd_conn) {
cifs_dbg(VFS, "RDMA transport established\n");
rc = 0;
goto smbd_connected;
} else {
rc = -ENOENT;
goto out_err_crypto_release;
}
}
rc = ip_connect(tcp_ses);
if (rc < 0) {
cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
goto out_err_crypto_release;
}
smbd_connected:
/*
* since we're in a cifs function already, we know that
* this will succeed. No need for try_module_get().
*/
__module_get(THIS_MODULE);
tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
tcp_ses, "cifsd");
if (IS_ERR(tcp_ses->tsk)) {
rc = PTR_ERR(tcp_ses->tsk);
cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
module_put(THIS_MODULE);
goto out_err_crypto_release;
}
tcp_ses->min_offload = ctx->min_offload;
/*
* at this point we are the only ones with the pointer
* to the struct since the kernel thread not created yet
* no need to spinlock this update of tcpStatus
*/
spin_lock(&tcp_ses->srv_lock);
tcp_ses->tcpStatus = CifsNeedNegotiate;
spin_unlock(&tcp_ses->srv_lock);
if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
else
tcp_ses->max_credits = ctx->max_credits;
tcp_ses->nr_targets = 1;
tcp_ses->ignore_signature = ctx->ignore_signature;
/* thread spawned, put it on the list */
spin_lock(&cifs_tcp_ses_lock);
list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
spin_unlock(&cifs_tcp_ses_lock);
/* queue echo request delayed work */
queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
/* queue dns resolution delayed work */
cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
__func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
return tcp_ses;
out_err_crypto_release:
cifs_crypto_secmech_release(tcp_ses);
put_net(cifs_net_ns(tcp_ses));
out_err:
if (tcp_ses) {
if (CIFS_SERVER_IS_CHAN(tcp_ses))
cifs_put_tcp_session(tcp_ses->primary_server, false);
kfree(tcp_ses->hostname);
if (tcp_ses->ssocket)
sock_release(tcp_ses->ssocket);
kfree(tcp_ses);
}
return ERR_PTR(rc);
}
/* this function must be called with ses_lock held */
static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
{
if (ctx->sectype != Unspecified &&
ctx->sectype != ses->sectype)
return 0;
/*
* If an existing session is limited to less channels than
* requested, it should not be reused
*/
spin_lock(&ses->chan_lock);
if (ses->chan_max < ctx->max_channels) {
spin_unlock(&ses->chan_lock);
return 0;
}
spin_unlock(&ses->chan_lock);
switch (ses->sectype) {
case Kerberos:
if (!uid_eq(ctx->cred_uid, ses->cred_uid))
return 0;
break;
default:
/* NULL username means anonymous session */
if (ses->user_name == NULL) {
if (!ctx->nullauth)
return 0;
break;
}
/* anything else takes username/password */
if (strncmp(ses->user_name,
ctx->username ? ctx->username : "",
CIFS_MAX_USERNAME_LEN))
return 0;
if ((ctx->username && strlen(ctx->username) != 0) &&
ses->password != NULL &&
strncmp(ses->password,
ctx->password ? ctx->password : "",
CIFS_MAX_PASSWORD_LEN))
return 0;
}
return 1;
}
/**
* cifs_setup_ipc - helper to setup the IPC tcon for the session
* @ses: smb session to issue the request on
* @ctx: the superblock configuration context to use for building the
* new tree connection for the IPC (interprocess communication RPC)
*
* A new IPC connection is made and stored in the session
* tcon_ipc. The IPC tcon has the same lifetime as the session.
*/
static int
cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
{
int rc = 0, xid;
struct cifs_tcon *tcon;
char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
bool seal = false;
struct TCP_Server_Info *server = ses->server;
/*
* If the mount request that resulted in the creation of the
* session requires encryption, force IPC to be encrypted too.
*/
if (ctx->seal) {
if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
seal = true;
else {
cifs_server_dbg(VFS,
"IPC: server doesn't support encryption\n");
return -EOPNOTSUPP;
}
}
tcon = tconInfoAlloc();
if (tcon == NULL)
return -ENOMEM;
scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
xid = get_xid();
tcon->ses = ses;
tcon->ipc = true;
tcon->seal = seal;
rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
free_xid(xid);
if (rc) {
cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
tconInfoFree(tcon);
goto out;
}
cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
ses->tcon_ipc = tcon;
out:
return rc;
}
/**
* cifs_free_ipc - helper to release the session IPC tcon
* @ses: smb session to unmount the IPC from
*
* Needs to be called everytime a session is destroyed.
*
* On session close, the IPC is closed and the server must release all tcons of the session.
* No need to send a tree disconnect here.
*
* Besides, it will make the server to not close durable and resilient files on session close, as
* specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
*/
static int
cifs_free_ipc(struct cifs_ses *ses)
{
struct cifs_tcon *tcon = ses->tcon_ipc;
if (tcon == NULL)
return 0;
tconInfoFree(tcon);
ses->tcon_ipc = NULL;
return 0;
}
static struct cifs_ses *
cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
{
struct cifs_ses *ses;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
spin_lock(&ses->ses_lock);
if (ses->ses_status == SES_EXITING) {
spin_unlock(&ses->ses_lock);
continue;
}
if (!match_session(ses, ctx)) {
spin_unlock(&ses->ses_lock);
continue;
}
spin_unlock(&ses->ses_lock);
++ses->ses_count;
spin_unlock(&cifs_tcp_ses_lock);
return ses;
}
spin_unlock(&cifs_tcp_ses_lock);
return NULL;
}
void cifs_put_smb_ses(struct cifs_ses *ses)
{
unsigned int rc, xid;
unsigned int chan_count;
struct TCP_Server_Info *server = ses->server;
spin_lock(&ses->ses_lock);
if (ses->ses_status == SES_EXITING) {
spin_unlock(&ses->ses_lock);
return;
}
spin_unlock(&ses->ses_lock);
cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
cifs_dbg(FYI,
"%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
spin_lock(&cifs_tcp_ses_lock);
if (--ses->ses_count > 0) {
spin_unlock(&cifs_tcp_ses_lock);
return;
}
spin_unlock(&cifs_tcp_ses_lock);
/* ses_count can never go negative */
WARN_ON(ses->ses_count < 0);
if (ses->ses_status == SES_GOOD)
ses->ses_status = SES_EXITING;
cifs_free_ipc(ses);
if (ses->ses_status == SES_EXITING && server->ops->logoff) {
xid = get_xid();
rc = server->ops->logoff(xid, ses);
if (rc)
cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
__func__, rc);
_free_xid(xid);
}
spin_lock(&cifs_tcp_ses_lock);
list_del_init(&ses->smb_ses_list);
spin_unlock(&cifs_tcp_ses_lock);
chan_count = ses->chan_count;
/* close any extra channels */
if (chan_count > 1) {
int i;
for (i = 1; i < chan_count; i++) {
if (ses->chans[i].iface) {
kref_put(&ses->chans[i].iface->refcount, release_iface);
ses->chans[i].iface = NULL;
}
cifs_put_tcp_session(ses->chans[i].server, 0);
ses->chans[i].server = NULL;
}
}
sesInfoFree(ses);
cifs_put_tcp_session(server, 0);
}
#ifdef CONFIG_KEYS
/* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
#define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
/* Populate username and pw fields from keyring if possible */
static int
cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
{
int rc = 0;
int is_domain = 0;
const char *delim, *payload;
char *desc;
ssize_t len;
struct key *key;
struct TCP_Server_Info *server = ses->server;
struct sockaddr_in *sa;
struct sockaddr_in6 *sa6;
const struct user_key_payload *upayload;
desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
if (!desc)
return -ENOMEM;
/* try to find an address key first */
switch (server->dstaddr.ss_family) {
case AF_INET:
sa = (struct sockaddr_in *)&server->dstaddr;
sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
break;
case AF_INET6:
sa6 = (struct sockaddr_in6 *)&server->dstaddr;
sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
break;
default:
cifs_dbg(FYI, "Bad ss_family (%hu)\n",
server->dstaddr.ss_family);
rc = -EINVAL;
goto out_err;
}
cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
key = request_key(&key_type_logon, desc, "");
if (IS_ERR(key)) {
if (!ses->domainName) {
cifs_dbg(FYI, "domainName is NULL\n");
rc = PTR_ERR(key);
goto out_err;
}
/* didn't work, try to find a domain key */
sprintf(desc, "cifs:d:%s", ses->domainName);
cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
key = request_key(&key_type_logon, desc, "");
if (IS_ERR(key)) {
rc = PTR_ERR(key);
goto out_err;
}
is_domain = 1;
}
down_read(&key->sem);
upayload = user_key_payload_locked(key);
if (IS_ERR_OR_NULL(upayload)) {
rc = upayload ? PTR_ERR(upayload) : -EINVAL;
goto out_key_put;
}
/* find first : in payload */
payload = upayload->data;
delim = strnchr(payload, upayload->datalen, ':');
cifs_dbg(FYI, "payload=%s\n", payload);
if (!delim) {
cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
upayload->datalen);
rc = -EINVAL;
goto out_key_put;
}
len = delim - payload;
if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
len);
rc = -EINVAL;
goto out_key_put;
}
ctx->username = kstrndup(payload, len, GFP_KERNEL);
if (!ctx->username) {
cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
len);
rc = -ENOMEM;
goto out_key_put;
}
cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
len = key->datalen - (len + 1);
if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
rc = -EINVAL;
kfree(ctx->username);
ctx->username = NULL;
goto out_key_put;
}
++delim;
ctx->password = kstrndup(delim, len, GFP_KERNEL);
if (!ctx->password) {
cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
len);
rc = -ENOMEM;
kfree(ctx->username);
ctx->username = NULL;
goto out_key_put;
}
/*
* If we have a domain key then we must set the domainName in the
* for the request.
*/
if (is_domain && ses->domainName) {
ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
if (!ctx->domainname) {
cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
len);
rc = -ENOMEM;
kfree(ctx->username);
ctx->username = NULL;
kfree_sensitive(ctx->password);
ctx->password = NULL;
goto out_key_put;
}
}
strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
out_key_put:
up_read(&key->sem);
key_put(key);
out_err:
kfree(desc);
cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
return rc;
}
#else /* ! CONFIG_KEYS */
static inline int
cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
struct cifs_ses *ses __attribute__((unused)))
{
return -ENOSYS;
}
#endif /* CONFIG_KEYS */
/**
* cifs_get_smb_ses - get a session matching @ctx data from @server
* @server: server to setup the session to
* @ctx: superblock configuration context to use to setup the session
*
* This function assumes it is being called from cifs_mount() where we
* already got a server reference (server refcount +1). See
* cifs_get_tcon() for refcount explanations.
*/
struct cifs_ses *
cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
{
int rc = -ENOMEM;
unsigned int xid;
struct cifs_ses *ses;
struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
xid = get_xid();
ses = cifs_find_smb_ses(server, ctx);
if (ses) {
cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
ses->ses_status);
spin_lock(&ses->chan_lock);
if (cifs_chan_needs_reconnect(ses, server)) {
spin_unlock(&ses->chan_lock);
cifs_dbg(FYI, "Session needs reconnect\n");
mutex_lock(&ses->session_mutex);
rc = cifs_negotiate_protocol(xid, ses, server);
if (rc) {
mutex_unlock(&ses->session_mutex);
/* problem -- put our ses reference */
cifs_put_smb_ses(ses);
free_xid(xid);
return ERR_PTR(rc);
}
rc = cifs_setup_session(xid, ses, server,
ctx->local_nls);
if (rc) {
mutex_unlock(&ses->session_mutex);
/* problem -- put our reference */
cifs_put_smb_ses(ses);
free_xid(xid);
return ERR_PTR(rc);
}
mutex_unlock(&ses->session_mutex);
spin_lock(&ses->chan_lock);
}
spin_unlock(&ses->chan_lock);
/* existing SMB ses has a server reference already */
cifs_put_tcp_session(server, 0);
free_xid(xid);
return ses;
}
cifs_dbg(FYI, "Existing smb sess not found\n");
ses = sesInfoAlloc();
if (ses == NULL)
goto get_ses_fail;
/* new SMB session uses our server ref */
ses->server = server;
if (server->dstaddr.ss_family == AF_INET6)
sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
else
sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
if (ctx->username) {
ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
if (!ses->user_name)
goto get_ses_fail;
}
/* ctx->password freed at unmount */
if (ctx->password) {
ses->password = kstrdup(ctx->password, GFP_KERNEL);
if (!ses->password)
goto get_ses_fail;
}
if (ctx->domainname) {
ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
if (!ses->domainName)
goto get_ses_fail;
}
strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
if (ctx->domainauto)
ses->domainAuto = ctx->domainauto;
ses->cred_uid = ctx->cred_uid;
ses->linux_uid = ctx->linux_uid;
ses->sectype = ctx->sectype;
ses->sign = ctx->sign;
/* add server as first channel */
spin_lock(&ses->chan_lock);
ses->chans[0].server = server;
ses->chan_count = 1;
ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
ses->chans_need_reconnect = 1;
spin_unlock(&ses->chan_lock);
mutex_lock(&ses->session_mutex);
rc = cifs_negotiate_protocol(xid, ses, server);
if (!rc)
rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
mutex_unlock(&ses->session_mutex);
/* each channel uses a different signing key */
spin_lock(&ses->chan_lock);
memcpy(ses->chans[0].signkey, ses->smb3signingkey,
sizeof(ses->smb3signingkey));
spin_unlock(&ses->chan_lock);
if (rc)
goto get_ses_fail;
/*
* success, put it on the list and add it as first channel
* note: the session becomes active soon after this. So you'll
* need to lock before changing something in the session.
*/
spin_lock(&cifs_tcp_ses_lock);
list_add(&ses->smb_ses_list, &server->smb_ses_list);
spin_unlock(&cifs_tcp_ses_lock);
free_xid(xid);
cifs_setup_ipc(ses, ctx);
return ses;
get_ses_fail:
sesInfoFree(ses);
free_xid(xid);
return ERR_PTR(rc);
}
/* this function must be called with tc_lock held */
static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
{
if (tcon->status == TID_EXITING)
return 0;
if (strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
return 0;
if (tcon->seal != ctx->seal)
return 0;
if (tcon->snapshot_time != ctx->snapshot_time)
return 0;
if (tcon->handle_timeout != ctx->handle_timeout)
return 0;
if (tcon->no_lease != ctx->no_lease)
return 0;
if (tcon->nodelete != ctx->nodelete)
return 0;
return 1;
}
static struct cifs_tcon *
cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
{
struct cifs_tcon *tcon;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
spin_lock(&tcon->tc_lock);
if (!match_tcon(tcon, ctx)) {
spin_unlock(&tcon->tc_lock);
continue;
}
++tcon->tc_count;
spin_unlock(&tcon->tc_lock);
spin_unlock(&cifs_tcp_ses_lock);
return tcon;
}
spin_unlock(&cifs_tcp_ses_lock);
return NULL;
}
void
cifs_put_tcon(struct cifs_tcon *tcon)
{
unsigned int xid;
struct cifs_ses *ses;
/*
* IPC tcon share the lifetime of their session and are
* destroyed in the session put function
*/
if (tcon == NULL || tcon->ipc)
return;
ses = tcon->ses;
cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
spin_lock(&cifs_tcp_ses_lock);
spin_lock(&tcon->tc_lock);
if (--tcon->tc_count > 0) {
spin_unlock(&tcon->tc_lock);
spin_unlock(&cifs_tcp_ses_lock);
return;
}
/* tc_count can never go negative */
WARN_ON(tcon->tc_count < 0);
list_del_init(&tcon->tcon_list);
spin_unlock(&tcon->tc_lock);
spin_unlock(&cifs_tcp_ses_lock);
/* cancel polling of interfaces */
cancel_delayed_work_sync(&tcon->query_interfaces);
if (tcon->use_witness) {
int rc;
rc = cifs_swn_unregister(tcon);
if (rc < 0) {
cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
__func__, rc);
}
}
xid = get_xid();
if (ses->server->ops->tree_disconnect)
ses->server->ops->tree_disconnect(xid, tcon);
_free_xid(xid);
cifs_fscache_release_super_cookie(tcon);
tconInfoFree(tcon);
cifs_put_smb_ses(ses);
}
/**
* cifs_get_tcon - get a tcon matching @ctx data from @ses
* @ses: smb session to issue the request on
* @ctx: the superblock configuration context to use for building the
*
* - tcon refcount is the number of mount points using the tcon.
* - ses refcount is the number of tcon using the session.
*
* 1. This function assumes it is being called from cifs_mount() where
* we already got a session reference (ses refcount +1).
*
* 2. Since we're in the context of adding a mount point, the end
* result should be either:
*
* a) a new tcon already allocated with refcount=1 (1 mount point) and
* its session refcount incremented (1 new tcon). This +1 was
* already done in (1).
*
* b) an existing tcon with refcount+1 (add a mount point to it) and
* identical ses refcount (no new tcon). Because of (1) we need to
* decrement the ses refcount.
*/
static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
{
int rc, xid;
struct cifs_tcon *tcon;
tcon = cifs_find_tcon(ses, ctx);
if (tcon) {
/*
* tcon has refcount already incremented but we need to
* decrement extra ses reference gotten by caller (case b)
*/
cifs_dbg(FYI, "Found match on UNC path\n");
cifs_put_smb_ses(ses);
return tcon;
}
if (!ses->server->ops->tree_connect) {
rc = -ENOSYS;
goto out_fail;
}
tcon = tconInfoAlloc();
if (tcon == NULL) {
rc = -ENOMEM;
goto out_fail;
}
if (ctx->snapshot_time) {
if (ses->server->vals->protocol_id == 0) {
cifs_dbg(VFS,
"Use SMB2 or later for snapshot mount option\n");
rc = -EOPNOTSUPP;
goto out_fail;
} else
tcon->snapshot_time = ctx->snapshot_time;
}
if (ctx->handle_timeout) {
if (ses->server->vals->protocol_id == 0) {
cifs_dbg(VFS,
"Use SMB2.1 or later for handle timeout option\n");
rc = -EOPNOTSUPP;
goto out_fail;
} else
tcon->handle_timeout = ctx->handle_timeout;
}
tcon->ses = ses;
if (ctx->password) {
tcon->password = kstrdup(ctx->password, GFP_KERNEL);
if (!tcon->password) {
rc = -ENOMEM;
goto out_fail;
}
}
if (ctx->seal) {
if (ses->server->vals->protocol_id == 0) {
cifs_dbg(VFS,
"SMB3 or later required for encryption\n");
rc = -EOPNOTSUPP;
goto out_fail;
} else if (tcon->ses->server->capabilities &
SMB2_GLOBAL_CAP_ENCRYPTION)
tcon->seal = true;
else {
cifs_dbg(VFS, "Encryption is not supported on share\n");
rc = -EOPNOTSUPP;
goto out_fail;
}
}
if (ctx->linux_ext) {
if (ses->server->posix_ext_supported) {
tcon->posix_extensions = true;
pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
} else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
(strcmp(ses->server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) ||
(strcmp(ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0)) {
cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
rc = -EOPNOTSUPP;
goto out_fail;
} else {
cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
"disabled but required for POSIX extensions\n");
rc = -EOPNOTSUPP;
goto out_fail;
}
}
xid = get_xid();
rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
ctx->local_nls);
free_xid(xid);
cifs_dbg(FYI, "Tcon rc = %d\n", rc);
if (rc)
goto out_fail;
tcon->use_persistent = false;
/* check if SMB2 or later, CIFS does not support persistent handles */
if (ctx->persistent) {
if (ses->server->vals->protocol_id == 0) {
cifs_dbg(VFS,
"SMB3 or later required for persistent handles\n");
rc = -EOPNOTSUPP;
goto out_fail;
} else if (ses->server->capabilities &
SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
tcon->use_persistent = true;
else /* persistent handles requested but not supported */ {
cifs_dbg(VFS,
"Persistent handles not supported on share\n");
rc = -EOPNOTSUPP;
goto out_fail;
}
} else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
&& (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
&& (ctx->nopersistent == false)) {
cifs_dbg(FYI, "enabling persistent handles\n");
tcon->use_persistent = true;
} else if (ctx->resilient) {
if (ses->server->vals->protocol_id == 0) {
cifs_dbg(VFS,
"SMB2.1 or later required for resilient handles\n");
rc = -EOPNOTSUPP;
goto out_fail;
}
tcon->use_resilient = true;
}
tcon->use_witness = false;
if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
/*
* Set witness in use flag in first place
* to retry registration in the echo task
*/
tcon->use_witness = true;
/* And try to register immediately */
rc = cifs_swn_register(tcon);
if (rc < 0) {
cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
goto out_fail;
}
} else {
/* TODO: try to extend for non-cluster uses (eg multichannel) */
cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
rc = -EOPNOTSUPP;
goto out_fail;
}
} else {
cifs_dbg(VFS, "SMB3 or later required for witness option\n");
rc = -EOPNOTSUPP;
goto out_fail;
}
}
/* If the user really knows what they are doing they can override */
if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
if (ctx->cache_ro)
cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
else if (ctx->cache_rw)
cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
}
if (ctx->no_lease) {
if (ses->server->vals->protocol_id == 0) {
cifs_dbg(VFS,
"SMB2 or later required for nolease option\n");
rc = -EOPNOTSUPP;
goto out_fail;
} else
tcon->no_lease = ctx->no_lease;
}
/*
* We can have only one retry value for a connection to a share so for
* resources mounted more than once to the same server share the last
* value passed in for the retry flag is used.
*/
tcon->retry = ctx->retry;
tcon->nocase = ctx->nocase;
tcon->broken_sparse_sup = ctx->no_sparse;
if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
tcon->nohandlecache = ctx->nohandlecache;
else
tcon->nohandlecache = true;
tcon->nodelete = ctx->nodelete;
tcon->local_lease = ctx->local_lease;
INIT_LIST_HEAD(&tcon->pending_opens);
/* schedule query interfaces poll */
INIT_DELAYED_WORK(&tcon->query_interfaces,
smb2_query_server_interfaces);
queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
(SMB_INTERFACE_POLL_INTERVAL * HZ));
spin_lock(&cifs_tcp_ses_lock);
list_add(&tcon->tcon_list, &ses->tcon_list);
spin_unlock(&cifs_tcp_ses_lock);
return tcon;
out_fail:
tconInfoFree(tcon);
return ERR_PTR(rc);
}
void
cifs_put_tlink(struct tcon_link *tlink)
{
if (!tlink || IS_ERR(tlink))
return;
if (!atomic_dec_and_test(&tlink->tl_count) ||
test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
tlink->tl_time = jiffies;
return;
}
if (!IS_ERR(tlink_tcon(tlink)))
cifs_put_tcon(tlink_tcon(tlink));
kfree(tlink);
return;
}
static int
compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
{
struct cifs_sb_info *old = CIFS_SB(sb);
struct cifs_sb_info *new = mnt_data->cifs_sb;
unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
return 0;
if (old->mnt_cifs_serverino_autodisabled)
newflags &= ~CIFS_MOUNT_SERVER_INUM;
if (oldflags != newflags)
return 0;
/*
* We want to share sb only if we don't specify an r/wsize or
* specified r/wsize is greater than or equal to existing one.
*/
if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
return 0;
if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
return 0;
if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
!gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
return 0;
if (old->ctx->file_mode != new->ctx->file_mode ||
old->ctx->dir_mode != new->ctx->dir_mode)
return 0;
if (strcmp(old->local_nls->charset, new->local_nls->charset))
return 0;
if (old->ctx->acregmax != new->ctx->acregmax)
return 0;
if (old->ctx->acdirmax != new->ctx->acdirmax)
return 0;
if (old->ctx->closetimeo != new->ctx->closetimeo)
return 0;
return 1;
}
static int
match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
{
struct cifs_sb_info *old = CIFS_SB(sb);
struct cifs_sb_info *new = mnt_data->cifs_sb;
bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
old->prepath;
bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
new->prepath;
if (old_set && new_set && !strcmp(new->prepath, old->prepath))
return 1;
else if (!old_set && !new_set)
return 1;
return 0;
}
int
cifs_match_super(struct super_block *sb, void *data)
{
struct cifs_mnt_data *mnt_data = data;
struct smb3_fs_context *ctx;
struct cifs_sb_info *cifs_sb;
struct TCP_Server_Info *tcp_srv;
struct cifs_ses *ses;
struct cifs_tcon *tcon;
struct tcon_link *tlink;
int rc = 0;
spin_lock(&cifs_tcp_ses_lock);
cifs_sb = CIFS_SB(sb);
tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
if (tlink == NULL) {
/* can not match superblock if tlink were ever null */
spin_unlock(&cifs_tcp_ses_lock);
return 0;
}
tcon = tlink_tcon(tlink);
ses = tcon->ses;
tcp_srv = ses->server;
ctx = mnt_data->ctx;
spin_lock(&tcp_srv->srv_lock);
spin_lock(&ses->ses_lock);
spin_lock(&tcon->tc_lock);
if (!match_server(tcp_srv, ctx) ||
!match_session(ses, ctx) ||
!match_tcon(tcon, ctx) ||
!match_prepath(sb, mnt_data)) {
rc = 0;
goto out;
}
rc = compare_mount_options(sb, mnt_data);
out:
spin_unlock(&tcon->tc_lock);
spin_unlock(&ses->ses_lock);
spin_unlock(&tcp_srv->srv_lock);
spin_unlock(&cifs_tcp_ses_lock);
cifs_put_tlink(tlink);
return rc;
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key cifs_key[2];
static struct lock_class_key cifs_slock_key[2];
static inline void
cifs_reclassify_socket4(struct socket *sock)
{
struct sock *sk = sock->sk;
BUG_ON(!sock_allow_reclassification(sk));
sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
&cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
}
static inline void
cifs_reclassify_socket6(struct socket *sock)
{
struct sock *sk = sock->sk;
BUG_ON(!sock_allow_reclassification(sk));
sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
&cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
}
#else
static inline void
cifs_reclassify_socket4(struct socket *sock)
{
}
static inline void
cifs_reclassify_socket6(struct socket *sock)
{
}
#endif
/* See RFC1001 section 14 on representation of Netbios names */
static void rfc1002mangle(char *target, char *source, unsigned int length)
{
unsigned int i, j;
for (i = 0, j = 0; i < (length); i++) {
/* mask a nibble at a time and encode */
target[j] = 'A' + (0x0F & (source[i] >> 4));
target[j+1] = 'A' + (0x0F & source[i]);
j += 2;
}
}
static int
bind_socket(struct TCP_Server_Info *server)
{
int rc = 0;
if (server->srcaddr.ss_family != AF_UNSPEC) {
/* Bind to the specified local IP address */
struct socket *socket = server->ssocket;
rc = socket->ops->bind(socket,
(struct sockaddr *) &server->srcaddr,
sizeof(server->srcaddr));
if (rc < 0) {
struct sockaddr_in *saddr4;
struct sockaddr_in6 *saddr6;
saddr4 = (struct sockaddr_in *)&server->srcaddr;
saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
if (saddr6->sin6_family == AF_INET6)
cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
&saddr6->sin6_addr, rc);
else
cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
&saddr4->sin_addr.s_addr, rc);
}
}
return rc;
}
static int
ip_rfc1001_connect(struct TCP_Server_Info *server)
{
int rc = 0;
/*
* some servers require RFC1001 sessinit before sending
* negprot - BB check reconnection in case where second
* sessinit is sent but no second negprot
*/
struct rfc1002_session_packet *ses_init_buf;
unsigned int req_noscope_len;
struct smb_hdr *smb_buf;
ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
GFP_KERNEL);
if (ses_init_buf) {
ses_init_buf->trailer.session_req.called_len = 32;
if (server->server_RFC1001_name[0] != 0)
rfc1002mangle(ses_init_buf->trailer.
session_req.called_name,
server->server_RFC1001_name,
RFC1001_NAME_LEN_WITH_NULL);
else
rfc1002mangle(ses_init_buf->trailer.
session_req.called_name,
DEFAULT_CIFS_CALLED_NAME,
RFC1001_NAME_LEN_WITH_NULL);
ses_init_buf->trailer.session_req.calling_len = 32;
/*
* calling name ends in null (byte 16) from old smb
* convention.
*/
if (server->workstation_RFC1001_name[0] != 0)
rfc1002mangle(ses_init_buf->trailer.
session_req.calling_name,
server->workstation_RFC1001_name,
RFC1001_NAME_LEN_WITH_NULL);
else
rfc1002mangle(ses_init_buf->trailer.
session_req.calling_name,
"LINUX_CIFS_CLNT",
RFC1001_NAME_LEN_WITH_NULL);
ses_init_buf->trailer.session_req.scope1 = 0;
ses_init_buf->trailer.session_req.scope2 = 0;
smb_buf = (struct smb_hdr *)ses_init_buf;
/* sizeof RFC1002_SESSION_REQUEST with no scopes */
req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
/* == cpu_to_be32(0x81000044) */
smb_buf->smb_buf_length =
cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
rc = smb_send(server, smb_buf, 0x44);
kfree(ses_init_buf);
/*
* RFC1001 layer in at least one server
* requires very short break before negprot
* presumably because not expecting negprot
* to follow so fast. This is a simple
* solution that works without
* complicating the code and causes no
* significant slowing down on mount
* for everyone else
*/
usleep_range(1000, 2000);
}
/*
* else the negprot may still work without this
* even though malloc failed
*/
return rc;
}
static int
generic_ip_connect(struct TCP_Server_Info *server)
{
int rc = 0;
__be16 sport;
int slen, sfamily;
struct socket *socket = server->ssocket;
struct sockaddr *saddr;
saddr = (struct sockaddr *) &server->dstaddr;
if (server->dstaddr.ss_family == AF_INET6) {
struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
sport = ipv6->sin6_port;
slen = sizeof(struct sockaddr_in6);
sfamily = AF_INET6;
cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
ntohs(sport));
} else {
struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
sport = ipv4->sin_port;
slen = sizeof(struct sockaddr_in);
sfamily = AF_INET;
cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
ntohs(sport));
}
if (socket == NULL) {
rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
IPPROTO_TCP, &socket, 1);
if (rc < 0) {
cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
server->ssocket = NULL;
return rc;
}
/* BB other socket options to set KEEPALIVE, NODELAY? */
cifs_dbg(FYI, "Socket created\n");
server->ssocket = socket;
socket->sk->sk_allocation = GFP_NOFS;
if (sfamily == AF_INET6)
cifs_reclassify_socket6(socket);
else
cifs_reclassify_socket4(socket);
}
rc = bind_socket(server);
if (rc < 0)
return rc;
/*
* Eventually check for other socket options to change from
* the default. sock_setsockopt not used because it expects
* user space buffer
*/
socket->sk->sk_rcvtimeo = 7 * HZ;
socket->sk->sk_sndtimeo = 5 * HZ;
/* make the bufsizes depend on wsize/rsize and max requests */
if (server->noautotune) {
if (socket->sk->sk_sndbuf < (200 * 1024))
socket->sk->sk_sndbuf = 200 * 1024;
if (socket->sk->sk_rcvbuf < (140 * 1024))
socket->sk->sk_rcvbuf = 140 * 1024;
}
if (server->tcp_nodelay)
tcp_sock_set_nodelay(socket->sk);
cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
socket->sk->sk_sndbuf,
socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
rc = socket->ops->connect(socket, saddr, slen,
server->noblockcnt ? O_NONBLOCK : 0);
/*
* When mounting SMB root file systems, we do not want to block in
* connect. Otherwise bail out and then let cifs_reconnect() perform
* reconnect failover - if possible.
*/
if (server->noblockcnt && rc == -EINPROGRESS)
rc = 0;
if (rc < 0) {
cifs_dbg(FYI, "Error %d connecting to server\n", rc);
trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
sock_release(socket);
server->ssocket = NULL;
return rc;
}
trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
if (sport == htons(RFC1001_PORT))
rc = ip_rfc1001_connect(server);
return rc;
}
static int
ip_connect(struct TCP_Server_Info *server)
{
__be16 *sport;
struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
if (server->dstaddr.ss_family == AF_INET6)
sport = &addr6->sin6_port;
else
sport = &addr->sin_port;
if (*sport == 0) {
int rc;
/* try with 445 port at first */
*sport = htons(CIFS_PORT);
rc = generic_ip_connect(server);
if (rc >= 0)
return rc;
/* if it failed, try with 139 port */
*sport = htons(RFC1001_PORT);
}
return generic_ip_connect(server);
}
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
{
/*
* If we are reconnecting then should we check to see if
* any requested capabilities changed locally e.g. via
* remount but we can not do much about it here
* if they have (even if we could detect it by the following)
* Perhaps we could add a backpointer to array of sb from tcon
* or if we change to make all sb to same share the same
* sb as NFS - then we only have one backpointer to sb.
* What if we wanted to mount the server share twice once with
* and once without posixacls or posix paths?
*/
__u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
if (ctx && ctx->no_linux_ext) {
tcon->fsUnixInfo.Capability = 0;
tcon->unix_ext = 0; /* Unix Extensions disabled */
cifs_dbg(FYI, "Linux protocol extensions disabled\n");
return;
} else if (ctx)
tcon->unix_ext = 1; /* Unix Extensions supported */
if (!tcon->unix_ext) {
cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
return;
}
if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
__u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
/*
* check for reconnect case in which we do not
* want to change the mount behavior if we can avoid it
*/
if (ctx == NULL) {
/*
* turn off POSIX ACL and PATHNAMES if not set
* originally at mount time
*/
if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
cifs_dbg(VFS, "POSIXPATH support change\n");
cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
} else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
cifs_dbg(VFS, "possible reconnect error\n");
cifs_dbg(VFS, "server disabled POSIX path support\n");
}
}
if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
cifs_dbg(VFS, "per-share encryption not supported yet\n");
cap &= CIFS_UNIX_CAP_MASK;
if (ctx && ctx->no_psx_acl)
cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
cifs_dbg(FYI, "negotiated posix acl support\n");
if (cifs_sb)
cifs_sb->mnt_cifs_flags |=
CIFS_MOUNT_POSIXACL;
}
if (ctx && ctx->posix_paths == 0)
cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
cifs_dbg(FYI, "negotiate posix pathnames\n");
if (cifs_sb)
cifs_sb->mnt_cifs_flags |=
CIFS_MOUNT_POSIX_PATHS;
}
cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
#ifdef CONFIG_CIFS_DEBUG2
if (cap & CIFS_UNIX_FCNTL_CAP)
cifs_dbg(FYI, "FCNTL cap\n");
if (cap & CIFS_UNIX_EXTATTR_CAP)
cifs_dbg(FYI, "EXTATTR cap\n");
if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
cifs_dbg(FYI, "POSIX path cap\n");
if (cap & CIFS_UNIX_XATTR_CAP)
cifs_dbg(FYI, "XATTR cap\n");
if (cap & CIFS_UNIX_POSIX_ACL_CAP)
cifs_dbg(FYI, "POSIX ACL cap\n");
if (cap & CIFS_UNIX_LARGE_READ_CAP)
cifs_dbg(FYI, "very large read cap\n");
if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
cifs_dbg(FYI, "very large write cap\n");
if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
cifs_dbg(FYI, "transport encryption cap\n");
if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
cifs_dbg(FYI, "mandatory transport encryption cap\n");
#endif /* CIFS_DEBUG2 */
if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
if (ctx == NULL)
cifs_dbg(FYI, "resetting capabilities failed\n");
else
cifs_dbg(VFS, "Negotiating Unix capabilities with the server failed. Consider mounting with the Unix Extensions disabled if problems are found by specifying the nounix mount option.\n");
}
}
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
{
struct smb3_fs_context *ctx = cifs_sb->ctx;
INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
spin_lock_init(&cifs_sb->tlink_tree_lock);
cifs_sb->tlink_tree = RB_ROOT;
cifs_dbg(FYI, "file mode: %04ho dir mode: %04ho\n",
ctx->file_mode, ctx->dir_mode);
/* this is needed for ASCII cp to Unicode converts */
if (ctx->iocharset == NULL) {
/* load_nls_default cannot return null */
cifs_sb->local_nls = load_nls_default();
} else {
cifs_sb->local_nls = load_nls(ctx->iocharset);
if (cifs_sb->local_nls == NULL) {
cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
ctx->iocharset);
return -ELIBACC;
}
}
ctx->local_nls = cifs_sb->local_nls;
smb3_update_mnt_flags(cifs_sb);
if (ctx->direct_io)
cifs_dbg(FYI, "mounting share using direct i/o\n");
if (ctx->cache_ro) {
cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
} else if (ctx->cache_rw) {
cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
CIFS_MOUNT_RW_CACHE);
}
if ((ctx->cifs_acl) && (ctx->dynperm))
cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
if (ctx->prepath) {
cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
if (cifs_sb->prepath == NULL)
return -ENOMEM;
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
}
return 0;
}
/* Release all succeed connections */
static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
{
int rc = 0;
if (mnt_ctx->tcon)
cifs_put_tcon(mnt_ctx->tcon);
else if (mnt_ctx->ses)
cifs_put_smb_ses(mnt_ctx->ses);
else if (mnt_ctx->server)
cifs_put_tcp_session(mnt_ctx->server, 0);
mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
free_xid(mnt_ctx->xid);
}
/* Get connections for tcp, ses and tcon */
static int mount_get_conns(struct mount_ctx *mnt_ctx)
{
int rc = 0;
struct TCP_Server_Info *server = NULL;
struct cifs_ses *ses = NULL;
struct cifs_tcon *tcon = NULL;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
unsigned int xid;
xid = get_xid();
/* get a reference to a tcp session */
server = cifs_get_tcp_session(ctx, NULL);
if (IS_ERR(server)) {
rc = PTR_ERR(server);
server = NULL;
goto out;
}
/* get a reference to a SMB session */
ses = cifs_get_smb_ses(server, ctx);
if (IS_ERR(ses)) {
rc = PTR_ERR(ses);
ses = NULL;
goto out;
}
if ((ctx->persistent == true) && (!(ses->server->capabilities &
SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
cifs_server_dbg(VFS, "persistent handles not supported by server\n");
rc = -EOPNOTSUPP;
goto out;
}
/* search for existing tcon to this server share */
tcon = cifs_get_tcon(ses, ctx);
if (IS_ERR(tcon)) {
rc = PTR_ERR(tcon);
tcon = NULL;
goto out;
}
/* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
if (tcon->posix_extensions)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
/* tell server which Unix caps we support */
if (cap_unix(tcon->ses)) {
/*
* reset of caps checks mount to see if unix extensions disabled
* for just this mount.
*/
reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
spin_lock(&tcon->ses->server->srv_lock);
if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
(le64_to_cpu(tcon->fsUnixInfo.Capability) &
CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
spin_unlock(&tcon->ses->server->srv_lock);
rc = -EACCES;
goto out;
}
spin_unlock(&tcon->ses->server->srv_lock);
} else
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
tcon->unix_ext = 0; /* server does not support them */
/* do not care if a following call succeed - informational */
if (!tcon->pipe && server->ops->qfs_tcon) {
server->ops->qfs_tcon(xid, tcon, cifs_sb);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
if (tcon->fsDevInfo.DeviceCharacteristics &
cpu_to_le32(FILE_READ_ONLY_DEVICE))
cifs_dbg(VFS, "mounted to read only share\n");
else if ((cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_RW_CACHE) == 0)
cifs_dbg(VFS, "read only mount of RW share\n");
/* no need to log a RW mount of a typical RW share */
}
}
/*
* Clamp the rsize/wsize mount arguments if they are too big for the server
* and set the rsize/wsize to the negotiated values if not passed in by
* the user on mount
*/
if ((cifs_sb->ctx->wsize == 0) ||
(cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
if ((cifs_sb->ctx->rsize == 0) ||
(cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
/*
* The cookie is initialized from volume info returned above.
* Inside cifs_fscache_get_super_cookie it checks
* that we do not get super cookie twice.
*/
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
cifs_fscache_get_super_cookie(tcon);
out:
mnt_ctx->server = server;
mnt_ctx->ses = ses;
mnt_ctx->tcon = tcon;
mnt_ctx->xid = xid;
return rc;
}
static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
struct cifs_tcon *tcon)
{
struct tcon_link *tlink;
/* hang the tcon off of the superblock */
tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
if (tlink == NULL)
return -ENOMEM;
tlink->tl_uid = ses->linux_uid;
tlink->tl_tcon = tcon;
tlink->tl_time = jiffies;
set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
cifs_sb->master_tlink = tlink;
spin_lock(&cifs_sb->tlink_tree_lock);
tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
spin_unlock(&cifs_sb->tlink_tree_lock);
queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
TLINK_IDLE_EXPIRE);
return 0;
}
#ifdef CONFIG_CIFS_DFS_UPCALL
/* Get unique dfs connections */
static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
{
int rc;
mnt_ctx->fs_ctx->nosharesock = true;
rc = mount_get_conns(mnt_ctx);
if (mnt_ctx->server) {
cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
spin_lock(&mnt_ctx->server->srv_lock);
mnt_ctx->server->is_dfs_conn = true;
spin_unlock(&mnt_ctx->server->srv_lock);
}
return rc;
}
/*
* cifs_build_path_to_root returns full path to root when we do not have an
* existing connection (tcon)
*/
static char *
build_unc_path_to_root(const struct smb3_fs_context *ctx,
const struct cifs_sb_info *cifs_sb, bool useppath)
{
char *full_path, *pos;
unsigned int pplen = useppath && ctx->prepath ?
strlen(ctx->prepath) + 1 : 0;
unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
if (unc_len > MAX_TREE_SIZE)
return ERR_PTR(-EINVAL);
full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
if (full_path == NULL)
return ERR_PTR(-ENOMEM);
memcpy(full_path, ctx->UNC, unc_len);
pos = full_path + unc_len;
if (pplen) {
*pos = CIFS_DIR_SEP(cifs_sb);
memcpy(pos + 1, ctx->prepath, pplen);
pos += pplen;
}
*pos = '\0'; /* add trailing null */
convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
return full_path;
}
/*
* expand_dfs_referral - Update cifs_sb from dfs referral path
*
* cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
* submount. Otherwise it will be left untouched.
*/
static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
struct dfs_info3_param *referral)
{
int rc;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
char *fake_devname = NULL, *mdata = NULL;
mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
&fake_devname);
if (IS_ERR(mdata)) {
rc = PTR_ERR(mdata);
mdata = NULL;
} else {
/*
* We can not clear out the whole structure since we no longer have an explicit
* function to parse a mount-string. Instead we need to clear out the individual
* fields that are no longer valid.
*/
kfree(ctx->prepath);
ctx->prepath = NULL;
rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
}
kfree(fake_devname);
kfree(cifs_sb->ctx->mount_options);
cifs_sb->ctx->mount_options = mdata;
return rc;
}
#endif
/* TODO: all callers to this are broken. We are not parsing mount_options here
* we should pass a clone of the original context?
*/
int
cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
{
int rc;
if (devname) {
cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
rc = smb3_parse_devname(devname, ctx);
if (rc) {
cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
return rc;
}
}
if (mntopts) {
char *ip;
rc = smb3_parse_opt(mntopts, "ip", &ip);
if (rc) {
cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
return rc;
}
rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
kfree(ip);
if (!rc) {
cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
return -EINVAL;
}
}
if (ctx->nullauth) {
cifs_dbg(FYI, "Anonymous login\n");
kfree(ctx->username);
ctx->username = NULL;
} else if (ctx->username) {
/* BB fixme parse for domain name here */
cifs_dbg(FYI, "Username: %s\n", ctx->username);
} else {
cifs_dbg(VFS, "No username specified\n");
/* In userspace mount helper we can get user name from alternate
locations such as env variables and files on disk */
return -EINVAL;
}
return 0;
}
static int
cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
unsigned int xid,
struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb,
char *full_path,
int added_treename)
{
int rc;
char *s;
char sep, tmp;
int skip = added_treename ? 1 : 0;
sep = CIFS_DIR_SEP(cifs_sb);
s = full_path;
rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
while (rc == 0) {
/* skip separators */
while (*s == sep)
s++;
if (!*s)
break;
/* next separator */
while (*s && *s != sep)
s++;
/*
* if the treename is added, we then have to skip the first
* part within the separators
*/
if (skip) {
skip = 0;
continue;
}
/*
* temporarily null-terminate the path at the end of
* the current component
*/
tmp = *s;
*s = 0;
rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
full_path);
*s = tmp;
}
return rc;
}
/*
* Check if path is remote (i.e. a DFS share).
*
* Return -EREMOTE if it is, otherwise 0 or -errno.
*/
static int is_path_remote(struct mount_ctx *mnt_ctx)
{
int rc;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
struct TCP_Server_Info *server = mnt_ctx->server;
unsigned int xid = mnt_ctx->xid;
struct cifs_tcon *tcon = mnt_ctx->tcon;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
char *full_path;
#ifdef CONFIG_CIFS_DFS_UPCALL
bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
#endif
if (!server->ops->is_path_accessible)
return -EOPNOTSUPP;
/*
* cifs_build_path_to_root works only when we have a valid tcon
*/
full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
tcon->Flags & SMB_SHARE_IS_IN_DFS);
if (full_path == NULL)
return -ENOMEM;
cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
full_path);
#ifdef CONFIG_CIFS_DFS_UPCALL
if (nodfs) {
if (rc == -EREMOTE)
rc = -EOPNOTSUPP;
goto out;
}
/* path *might* exist with non-ASCII characters in DFS root
* try again with full path (only if nodfs is not set) */
if (rc == -ENOENT && is_tcon_dfs(tcon))
rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
full_path);
#endif
if (rc != 0 && rc != -EREMOTE)
goto out;
if (rc != -EREMOTE) {
rc = cifs_are_all_path_components_accessible(server, xid, tcon,
cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
if (rc != 0) {
cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
rc = 0;
}
}
out:
kfree(full_path);
return rc;
}
#ifdef CONFIG_CIFS_DFS_UPCALL
static void set_root_ses(struct mount_ctx *mnt_ctx)
{
if (mnt_ctx->ses) {
spin_lock(&cifs_tcp_ses_lock);
mnt_ctx->ses->ses_count++;
spin_unlock(&cifs_tcp_ses_lock);
dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
}
mnt_ctx->root_ses = mnt_ctx->ses;
}
static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
{
int rc;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
*isdfs = true;
rc = mount_get_conns(mnt_ctx);
/*
* If called with 'nodfs' mount option, then skip DFS resolving. Otherwise unconditionally
* try to get an DFS referral (even cached) to determine whether it is an DFS mount.
*
* Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
* to respond with PATH_NOT_COVERED to requests that include the prefix.
*/
if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
ctx->UNC + 1, NULL, root_tl)) {
if (rc)
return rc;
/* Check if it is fully accessible and then mount it */
rc = is_path_remote(mnt_ctx);
if (!rc)
*isdfs = false;
else if (rc != -EREMOTE)
return rc;
}
return 0;
}
static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
const char *ref_path, struct dfs_cache_tgt_iterator *tit)
{
int rc;
struct dfs_info3_param ref = {};
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
char *oldmnt = cifs_sb->ctx->mount_options;
cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
dfs_cache_get_tgt_name(tit));
rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
if (rc)
goto out;
rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
if (rc)
goto out;
/* Connect to new target only if we were redirected (e.g. mount options changed) */
if (oldmnt != cifs_sb->ctx->mount_options) {
mount_put_conns(mnt_ctx);
rc = mount_get_dfs_conns(mnt_ctx);
}
if (!rc) {
if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
set_root_ses(mnt_ctx);
rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
cifs_remap(cifs_sb), ref_path, tit);
}
out:
free_dfs_info_param(&ref);
return rc;
}
static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
{
int rc;
char *full_path;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
struct dfs_cache_tgt_iterator *tit;
/* Put initial connections as they might be shared with other mounts. We need unique dfs
* connections per mount to properly failover, so mount_get_dfs_conns() must be used from
* now on.
*/
mount_put_conns(mnt_ctx);
mount_get_dfs_conns(mnt_ctx);
set_root_ses(mnt_ctx);
full_path = build_unc_path_to_root(ctx, cifs_sb, true);
if (IS_ERR(full_path))
return PTR_ERR(full_path);
mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
cifs_remap(cifs_sb));
if (IS_ERR(mnt_ctx->origin_fullpath)) {
rc = PTR_ERR(mnt_ctx->origin_fullpath);
mnt_ctx->origin_fullpath = NULL;
goto out;
}
/* Try all dfs root targets */
for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
if (!rc) {
mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
if (!mnt_ctx->leaf_fullpath)
rc = -ENOMEM;
break;
}
}
out:
kfree(full_path);
return rc;
}
static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
{
int rc;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
char *full_path;
struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
struct dfs_cache_tgt_iterator *tit;
full_path = build_unc_path_to_root(ctx, cifs_sb, true);
if (IS_ERR(full_path))
return PTR_ERR(full_path);
kfree(mnt_ctx->leaf_fullpath);
mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
cifs_remap(cifs_sb));
if (IS_ERR(mnt_ctx->leaf_fullpath)) {
rc = PTR_ERR(mnt_ctx->leaf_fullpath);
mnt_ctx->leaf_fullpath = NULL;
goto out;
}
/* Get referral from dfs link */
rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
if (rc)
goto out;
/* Try all dfs link targets. If an I/O fails from currently connected DFS target with an
* error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
* specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
* STATUS_PATH_NOT_COVERED."
*/
for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
if (!rc) {
rc = is_path_remote(mnt_ctx);
if (!rc || rc == -EREMOTE)
break;
}
}
out:
kfree(full_path);
dfs_cache_free_tgts(&tl);
return rc;
}
static int follow_dfs_link(struct mount_ctx *mnt_ctx)
{
int rc;
struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
char *full_path;
int num_links = 0;
full_path = build_unc_path_to_root(ctx, cifs_sb, true);
if (IS_ERR(full_path))
return PTR_ERR(full_path);
kfree(mnt_ctx->origin_fullpath);
mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
cifs_remap(cifs_sb));
kfree(full_path);
if (IS_ERR(mnt_ctx->origin_fullpath)) {
rc = PTR_ERR(mnt_ctx->origin_fullpath);
mnt_ctx->origin_fullpath = NULL;
return rc;
}
do {
rc = __follow_dfs_link(mnt_ctx);
if (!rc || rc != -EREMOTE)
break;
} while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
return rc;
}
/* Set up DFS referral paths for failover */
static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
{
struct TCP_Server_Info *server = mnt_ctx->server;
mutex_lock(&server->refpath_lock);
server->origin_fullpath = mnt_ctx->origin_fullpath;
server->leaf_fullpath = mnt_ctx->leaf_fullpath;
server->current_fullpath = mnt_ctx->leaf_fullpath;
mutex_unlock(&server->refpath_lock);
mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
}
int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
{
int rc;
struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
bool isdfs;
rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
if (rc)
goto error;
if (!isdfs)
goto out;
/* proceed as DFS mount */
uuid_gen(&mnt_ctx.mount_id);
rc = connect_dfs_root(&mnt_ctx, &tl);
dfs_cache_free_tgts(&tl);
if (rc)
goto error;
rc = is_path_remote(&mnt_ctx);
if (rc)
rc = follow_dfs_link(&mnt_ctx);
if (rc)
goto error;
setup_server_referral_paths(&mnt_ctx);
/*
* After reconnecting to a different server, unique ids won't match anymore, so we disable
* serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
*/
cifs_autodisable_serverino(cifs_sb);
/*
* Force the use of prefix path to support failover on DFS paths that resolve to targets
* that have different prefix paths.
*/
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
kfree(cifs_sb->prepath);
cifs_sb->prepath = ctx->prepath;
ctx->prepath = NULL;
uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
out:
cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
if (rc)
goto error;
free_xid(mnt_ctx.xid);
return rc;
error:
dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
kfree(mnt_ctx.origin_fullpath);
kfree(mnt_ctx.leaf_fullpath);
mount_put_conns(&mnt_ctx);
return rc;
}
#else
int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
{
int rc = 0;
struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
rc = mount_get_conns(&mnt_ctx);
if (rc)
goto error;
if (mnt_ctx.tcon) {
rc = is_path_remote(&mnt_ctx);
if (rc == -EREMOTE)
rc = -EOPNOTSUPP;
if (rc)
goto error;
}
rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
if (rc)
goto error;
free_xid(mnt_ctx.xid);
return rc;
error:
mount_put_conns(&mnt_ctx);
return rc;
}
#endif
/*
* Issue a TREE_CONNECT request.
*/
int
CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
const char *tree, struct cifs_tcon *tcon,
const struct nls_table *nls_codepage)
{
struct smb_hdr *smb_buffer;
struct smb_hdr *smb_buffer_response;
TCONX_REQ *pSMB;
TCONX_RSP *pSMBr;
unsigned char *bcc_ptr;
int rc = 0;
int length;
__u16 bytes_left, count;
if (ses == NULL)
return -EIO;
smb_buffer = cifs_buf_get();
if (smb_buffer == NULL)
return -ENOMEM;
smb_buffer_response = smb_buffer;
header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
NULL /*no tid */ , 4 /*wct */ );
smb_buffer->Mid = get_next_mid(ses->server);
smb_buffer->Uid = ses->Suid;
pSMB = (TCONX_REQ *) smb_buffer;
pSMBr = (TCONX_RSP *) smb_buffer_response;
pSMB->AndXCommand = 0xFF;
pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
bcc_ptr = &pSMB->Password[0];
pSMB->PasswordLength = cpu_to_le16(1); /* minimum */
*bcc_ptr = 0; /* password is null byte */
bcc_ptr++; /* skip password */
/* already aligned so no need to do it below */
if (ses->server->sign)
smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
if (ses->capabilities & CAP_STATUS32) {
smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
}
if (ses->capabilities & CAP_DFS) {
smb_buffer->Flags2 |= SMBFLG2_DFS;
}
if (ses->capabilities & CAP_UNICODE) {
smb_buffer->Flags2 |= SMBFLG2_UNICODE;
length =
cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
6 /* max utf8 char length in bytes */ *
(/* server len*/ + 256 /* share len */), nls_codepage);
bcc_ptr += 2 * length; /* convert num 16 bit words to bytes */
bcc_ptr += 2; /* skip trailing null */
} else { /* ASCII */
strcpy(bcc_ptr, tree);
bcc_ptr += strlen(tree) + 1;
}
strcpy(bcc_ptr, "?????");
bcc_ptr += strlen("?????");
bcc_ptr += 1;
count = bcc_ptr - &pSMB->Password[0];
be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
pSMB->ByteCount = cpu_to_le16(count);
rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
0);
/* above now done in SendReceive */
if (rc == 0) {
bool is_unicode;
tcon->tid = smb_buffer_response->Tid;
bcc_ptr = pByteArea(smb_buffer_response);
bytes_left = get_bcc(smb_buffer_response);
length = strnlen(bcc_ptr, bytes_left - 2);
if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
is_unicode = true;
else
is_unicode = false;
/* skip service field (NB: this field is always ASCII) */
if (length == 3) {
if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
(bcc_ptr[2] == 'C')) {
cifs_dbg(FYI, "IPC connection\n");
tcon->ipc = true;
tcon->pipe = true;
}
} else if (length == 2) {
if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
/* the most common case */
cifs_dbg(FYI, "disk share connection\n");
}
}
bcc_ptr += length + 1;
bytes_left -= (length + 1);
strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
/* mostly informational -- no need to fail on error here */
kfree(tcon->nativeFileSystem);
tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
bytes_left, is_unicode,
nls_codepage);
cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
if ((smb_buffer_response->WordCount == 3) ||
(smb_buffer_response->WordCount == 7))
/* field is in same location */
tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
else
tcon->Flags = 0;
cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
}
cifs_buf_release(smb_buffer);
return rc;
}
static void delayed_free(struct rcu_head *p)
{
struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
unload_nls(cifs_sb->local_nls);
smb3_cleanup_fs_context(cifs_sb->ctx);
kfree(cifs_sb);
}
void
cifs_umount(struct cifs_sb_info *cifs_sb)
{
struct rb_root *root = &cifs_sb->tlink_tree;
struct rb_node *node;
struct tcon_link *tlink;
cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
spin_lock(&cifs_sb->tlink_tree_lock);
while ((node = rb_first(root))) {
tlink = rb_entry(node, struct tcon_link, tl_rbnode);
cifs_get_tlink(tlink);
clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
rb_erase(node, root);
spin_unlock(&cifs_sb->tlink_tree_lock);
cifs_put_tlink(tlink);
spin_lock(&cifs_sb->tlink_tree_lock);
}
spin_unlock(&cifs_sb->tlink_tree_lock);
kfree(cifs_sb->prepath);
#ifdef CONFIG_CIFS_DFS_UPCALL
dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
#endif
call_rcu(&cifs_sb->rcu, delayed_free);
}
int
cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
struct TCP_Server_Info *server)
{
int rc = 0;
if (!server->ops->need_neg || !server->ops->negotiate)
return -ENOSYS;
/* only send once per connect */
spin_lock(&server->srv_lock);
if (!server->ops->need_neg(server) ||
server->tcpStatus != CifsNeedNegotiate) {
spin_unlock(&server->srv_lock);
return 0;
}
server->tcpStatus = CifsInNegotiate;
spin_unlock(&server->srv_lock);
rc = server->ops->negotiate(xid, ses, server);
if (rc == 0) {
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsInNegotiate)
server->tcpStatus = CifsGood;
else
rc = -EHOSTDOWN;
spin_unlock(&server->srv_lock);
} else {
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsInNegotiate)
server->tcpStatus = CifsNeedNegotiate;
spin_unlock(&server->srv_lock);
}
return rc;
}
int
cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
struct TCP_Server_Info *server,
struct nls_table *nls_info)
{
int rc = -ENOSYS;
struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
bool is_binding = false;
spin_lock(&ses->ses_lock);
if (server->dstaddr.ss_family == AF_INET6)
scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
else
scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
if (ses->ses_status != SES_GOOD &&
ses->ses_status != SES_NEW &&
ses->ses_status != SES_NEED_RECON) {
spin_unlock(&ses->ses_lock);
return 0;
}
/* only send once per connect */
spin_lock(&ses->chan_lock);
if (CIFS_ALL_CHANS_GOOD(ses) ||
cifs_chan_in_reconnect(ses, server)) {
spin_unlock(&ses->chan_lock);
spin_unlock(&ses->ses_lock);
return 0;
}
is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
cifs_chan_set_in_reconnect(ses, server);
spin_unlock(&ses->chan_lock);
if (!is_binding)
ses->ses_status = SES_IN_SETUP;
spin_unlock(&ses->ses_lock);
if (!is_binding) {
ses->capabilities = server->capabilities;
if (!linuxExtEnabled)
ses->capabilities &= (~server->vals->cap_unix);
if (ses->auth_key.response) {
cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
ses->auth_key.response);
kfree_sensitive(ses->auth_key.response);
ses->auth_key.response = NULL;
ses->auth_key.len = 0;
}
}
cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
server->sec_mode, server->capabilities, server->timeAdj);
if (server->ops->sess_setup)
rc = server->ops->sess_setup(xid, ses, server, nls_info);
if (rc) {
cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
spin_lock(&ses->ses_lock);
if (ses->ses_status == SES_IN_SETUP)
ses->ses_status = SES_NEED_RECON;
spin_lock(&ses->chan_lock);
cifs_chan_clear_in_reconnect(ses, server);
spin_unlock(&ses->chan_lock);
spin_unlock(&ses->ses_lock);
} else {
spin_lock(&ses->ses_lock);
if (ses->ses_status == SES_IN_SETUP)
ses->ses_status = SES_GOOD;
spin_lock(&ses->chan_lock);
cifs_chan_clear_in_reconnect(ses, server);
cifs_chan_clear_need_reconnect(ses, server);
spin_unlock(&ses->chan_lock);
spin_unlock(&ses->ses_lock);
}
return rc;
}
static int
cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
{
ctx->sectype = ses->sectype;
/* krb5 is special, since we don't need username or pw */
if (ctx->sectype == Kerberos)
return 0;
return cifs_set_cifscreds(ctx, ses);
}
static struct cifs_tcon *
cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
{
int rc;
struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
struct cifs_ses *ses;
struct cifs_tcon *tcon = NULL;
struct smb3_fs_context *ctx;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (ctx == NULL)
return ERR_PTR(-ENOMEM);
ctx->local_nls = cifs_sb->local_nls;
ctx->linux_uid = fsuid;
ctx->cred_uid = fsuid;
ctx->UNC = master_tcon->tree_name;
ctx->retry = master_tcon->retry;
ctx->nocase = master_tcon->nocase;
ctx->nohandlecache = master_tcon->nohandlecache;
ctx->local_lease = master_tcon->local_lease;
ctx->no_lease = master_tcon->no_lease;
ctx->resilient = master_tcon->use_resilient;
ctx->persistent = master_tcon->use_persistent;
ctx->handle_timeout = master_tcon->handle_timeout;
ctx->no_linux_ext = !master_tcon->unix_ext;
ctx->linux_ext = master_tcon->posix_extensions;
ctx->sectype = master_tcon->ses->sectype;
ctx->sign = master_tcon->ses->sign;
ctx->seal = master_tcon->seal;
ctx->witness = master_tcon->use_witness;
rc = cifs_set_vol_auth(ctx, master_tcon->ses);
if (rc) {
tcon = ERR_PTR(rc);
goto out;
}
/* get a reference for the same TCP session */
spin_lock(&cifs_tcp_ses_lock);
++master_tcon->ses->server->srv_count;
spin_unlock(&cifs_tcp_ses_lock);
ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
if (IS_ERR(ses)) {
tcon = (struct cifs_tcon *)ses;
cifs_put_tcp_session(master_tcon->ses->server, 0);
goto out;
}
tcon = cifs_get_tcon(ses, ctx);
if (IS_ERR(tcon)) {
cifs_put_smb_ses(ses);
goto out;
}
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
if (cap_unix(ses))
reset_cifs_unix_caps(0, tcon, NULL, ctx);
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
out:
kfree(ctx->username);
kfree_sensitive(ctx->password);
kfree(ctx);
return tcon;
}
struct cifs_tcon *
cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
{
return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
}
/* find and return a tlink with given uid */
static struct tcon_link *
tlink_rb_search(struct rb_root *root, kuid_t uid)
{
struct rb_node *node = root->rb_node;
struct tcon_link *tlink;
while (node) {
tlink = rb_entry(node, struct tcon_link, tl_rbnode);
if (uid_gt(tlink->tl_uid, uid))
node = node->rb_left;
else if (uid_lt(tlink->tl_uid, uid))
node = node->rb_right;
else
return tlink;
}
return NULL;
}
/* insert a tcon_link into the tree */
static void
tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
{
struct rb_node **new = &(root->rb_node), *parent = NULL;
struct tcon_link *tlink;
while (*new) {
tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
parent = *new;
if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
new = &((*new)->rb_left);
else
new = &((*new)->rb_right);
}
rb_link_node(&new_tlink->tl_rbnode, parent, new);
rb_insert_color(&new_tlink->tl_rbnode, root);
}
/*
* Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
* current task.
*
* If the superblock doesn't refer to a multiuser mount, then just return
* the master tcon for the mount.
*
* First, search the rbtree for an existing tcon for this fsuid. If one
* exists, then check to see if it's pending construction. If it is then wait
* for construction to complete. Once it's no longer pending, check to see if
* it failed and either return an error or retry construction, depending on
* the timeout.
*
* If one doesn't exist then insert a new tcon_link struct into the tree and
* try to construct a new one.
*/
struct tcon_link *
cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
{
int ret;
kuid_t fsuid = current_fsuid();
struct tcon_link *tlink, *newtlink;
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
spin_lock(&cifs_sb->tlink_tree_lock);
tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
if (tlink)
cifs_get_tlink(tlink);
spin_unlock(&cifs_sb->tlink_tree_lock);
if (tlink == NULL) {
newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
if (newtlink == NULL)
return ERR_PTR(-ENOMEM);
newtlink->tl_uid = fsuid;
newtlink->tl_tcon = ERR_PTR(-EACCES);
set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
cifs_get_tlink(newtlink);
spin_lock(&cifs_sb->tlink_tree_lock);
/* was one inserted after previous search? */
tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
if (tlink) {
cifs_get_tlink(tlink);
spin_unlock(&cifs_sb->tlink_tree_lock);
kfree(newtlink);
goto wait_for_construction;
}
tlink = newtlink;
tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
spin_unlock(&cifs_sb->tlink_tree_lock);
} else {
wait_for_construction:
ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
TASK_INTERRUPTIBLE);
if (ret) {
cifs_put_tlink(tlink);
return ERR_PTR(-ERESTARTSYS);
}
/* if it's good, return it */
if (!IS_ERR(tlink->tl_tcon))
return tlink;
/* return error if we tried this already recently */
if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
cifs_put_tlink(tlink);
return ERR_PTR(-EACCES);
}
if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
goto wait_for_construction;
}
tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
if (IS_ERR(tlink->tl_tcon)) {
cifs_put_tlink(tlink);
return ERR_PTR(-EACCES);
}
return tlink;
}
/*
* periodic workqueue job that scans tcon_tree for a superblock and closes
* out tcons.
*/
static void
cifs_prune_tlinks(struct work_struct *work)
{
struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
prune_tlinks.work);
struct rb_root *root = &cifs_sb->tlink_tree;
struct rb_node *node;
struct rb_node *tmp;
struct tcon_link *tlink;
/*
* Because we drop the spinlock in the loop in order to put the tlink
* it's not guarded against removal of links from the tree. The only
* places that remove entries from the tree are this function and
* umounts. Because this function is non-reentrant and is canceled
* before umount can proceed, this is safe.
*/
spin_lock(&cifs_sb->tlink_tree_lock);
node = rb_first(root);
while (node != NULL) {
tmp = node;
node = rb_next(tmp);
tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
atomic_read(&tlink->tl_count) != 0 ||
time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
continue;
cifs_get_tlink(tlink);
clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
rb_erase(tmp, root);
spin_unlock(&cifs_sb->tlink_tree_lock);
cifs_put_tlink(tlink);
spin_lock(&cifs_sb->tlink_tree_lock);
}
spin_unlock(&cifs_sb->tlink_tree_lock);
queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
TLINK_IDLE_EXPIRE);
}
#ifdef CONFIG_CIFS_DFS_UPCALL
/* Update dfs referral path of superblock */
static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
const char *target)
{
int rc = 0;
size_t len = strlen(target);
char *refpath, *npath;
if (unlikely(len < 2 || *target != '\\'))
return -EINVAL;
if (target[1] == '\\') {
len += 1;
refpath = kmalloc(len, GFP_KERNEL);
if (!refpath)
return -ENOMEM;
scnprintf(refpath, len, "%s", target);
} else {
len += sizeof("\\");
refpath = kmalloc(len, GFP_KERNEL);
if (!refpath)
return -ENOMEM;
scnprintf(refpath, len, "\\%s", target);
}
npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
kfree(refpath);
if (IS_ERR(npath)) {
rc = PTR_ERR(npath);
} else {
mutex_lock(&server->refpath_lock);
kfree(server->leaf_fullpath);
server->leaf_fullpath = npath;
mutex_unlock(&server->refpath_lock);
server->current_fullpath = server->leaf_fullpath;
}
return rc;
}
static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
size_t tcp_host_len, char *share, bool *target_match)
{
int rc = 0;
const char *dfs_host;
size_t dfs_host_len;
*target_match = true;
extract_unc_hostname(share, &dfs_host, &dfs_host_len);
/* Check if hostnames or addresses match */
if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
dfs_host, (int)tcp_host_len, tcp_host);
rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
if (rc)
cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
}
return rc;
}
static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, char *tree, bool islink,
struct dfs_cache_tgt_list *tl)
{
int rc;
struct TCP_Server_Info *server = tcon->ses->server;
const struct smb_version_operations *ops = server->ops;
struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
char *share = NULL, *prefix = NULL;
const char *tcp_host;
size_t tcp_host_len;
struct dfs_cache_tgt_iterator *tit;
bool target_match;
extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
tit = dfs_cache_get_tgt_iterator(tl);
if (!tit) {
rc = -ENOENT;
goto out;
}
/* Try to tree connect to all dfs targets */
for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
const char *target = dfs_cache_get_tgt_name(tit);
struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
kfree(share);
kfree(prefix);
share = prefix = NULL;
/* Check if share matches with tcp ses */
rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
if (rc) {
cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
break;
}
rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
&target_match);
if (rc)
break;
if (!target_match) {
rc = -EHOSTUNREACH;
continue;
}
if (ipc->need_reconnect) {
scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
if (rc)
break;
}
scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
if (!islink) {
rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
break;
}
/*
* If no dfs referrals were returned from link target, then just do a TREE_CONNECT
* to it. Otherwise, cache the dfs referral and then mark current tcp ses for
* reconnect so either the demultiplex thread or the echo worker will reconnect to
* newly resolved target.
*/
if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
NULL, &ntl)) {
rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
if (rc)
continue;
rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
if (!rc)
rc = cifs_update_super_prepath(cifs_sb, prefix);
} else {
/* Target is another dfs share */
rc = update_server_fullpath(server, cifs_sb, target);
dfs_cache_free_tgts(tl);
if (!rc) {
rc = -EREMOTE;
list_replace_init(&ntl.tl_list, &tl->tl_list);
} else
dfs_cache_free_tgts(&ntl);
}
break;
}
out:
kfree(share);
kfree(prefix);
return rc;
}
static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, char *tree, bool islink,
struct dfs_cache_tgt_list *tl)
{
int rc;
int num_links = 0;
struct TCP_Server_Info *server = tcon->ses->server;
do {
rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
if (!rc || rc != -EREMOTE)
break;
} while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
/*
* If we couldn't tree connect to any targets from last referral path, then retry from
* original referral path.
*/
if (rc && server->current_fullpath != server->origin_fullpath) {
server->current_fullpath = server->origin_fullpath;
cifs_signal_cifsd_for_reconnect(server, true);
}
dfs_cache_free_tgts(tl);
return rc;
}
int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
{
int rc;
struct TCP_Server_Info *server = tcon->ses->server;
const struct smb_version_operations *ops = server->ops;
struct super_block *sb = NULL;
struct cifs_sb_info *cifs_sb;
struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
char *tree;
struct dfs_info3_param ref = {0};
/* only send once per connect */
spin_lock(&tcon->tc_lock);
if (tcon->ses->ses_status != SES_GOOD ||
(tcon->status != TID_NEW &&
tcon->status != TID_NEED_TCON)) {
spin_unlock(&tcon->tc_lock);
return 0;
}
tcon->status = TID_IN_TCON;
spin_unlock(&tcon->tc_lock);
tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
if (!tree) {
rc = -ENOMEM;
goto out;
}
if (tcon->ipc) {
scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
goto out;
}
sb = cifs_get_tcp_super(server);
if (IS_ERR(sb)) {
rc = PTR_ERR(sb);
cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
goto out;
}
cifs_sb = CIFS_SB(sb);
/* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
if (!server->current_fullpath ||
dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls);
goto out;
}
rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
&tl);
free_dfs_info_param(&ref);
out:
kfree(tree);
cifs_put_tcp_super(sb);
if (rc) {
spin_lock(&tcon->tc_lock);
if (tcon->status == TID_IN_TCON)
tcon->status = TID_NEED_TCON;
spin_unlock(&tcon->tc_lock);
} else {
spin_lock(&tcon->tc_lock);
if (tcon->status == TID_IN_TCON)
tcon->status = TID_GOOD;
spin_unlock(&tcon->tc_lock);
tcon->need_reconnect = false;
}
return rc;
}
#else
int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
{
int rc;
const struct smb_version_operations *ops = tcon->ses->server->ops;
/* only send once per connect */
spin_lock(&tcon->tc_lock);
if (tcon->ses->ses_status != SES_GOOD ||
(tcon->status != TID_NEW &&
tcon->status != TID_NEED_TCON)) {
spin_unlock(&tcon->tc_lock);
return 0;
}
tcon->status = TID_IN_TCON;
spin_unlock(&tcon->tc_lock);
rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
if (rc) {
spin_lock(&tcon->tc_lock);
if (tcon->status == TID_IN_TCON)
tcon->status = TID_NEED_TCON;
spin_unlock(&tcon->tc_lock);
} else {
spin_lock(&tcon->tc_lock);
if (tcon->status == TID_IN_TCON)
tcon->status = TID_GOOD;
tcon->need_reconnect = false;
spin_unlock(&tcon->tc_lock);
}
return rc;
}
#endif
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