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OpenCloudOS-Kernel/fs/cifs/connect.c

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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);
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(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;
smb_msg->msg_control = NULL;
smb_msg->msg_controllen = 0;
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
*/
smb_msg.msg_name = NULL;
smb_msg.msg_namelen = 0;
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(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
kfree(server->hostname);
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->treeName : "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->treeName, 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);
if (--tcon->tc_count > 0) {
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(&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;
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 scope */
smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
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:
free_xid(mnt_ctx.xid);
cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
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;
}
free_xid(mnt_ctx.xid);
return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
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];
if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
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->treeName, tree, sizeof(tcon->treeName));
/* 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(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->treeName;
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->treeName, 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->treeName, 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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