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connect.c
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// SPDX-License-Identifier: LGPL-2.1
/*
*
* Copyright (C) International Business Machines Corp., 2002,2011
* Author(s): Steve French ([email protected])
*
*/
#include <linux/fs.h>
#include <linux/net.h>
#include <linux/string.h>
#include <linux/sched/mm.h>
#include <linux/sched/signal.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/utsname.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/pagevec.h>
#include <linux/freezer.h>
#include <linux/namei.h>
#include <linux/uuid.h>
#include <linux/uaccess.h>
#include <asm/processor.h>
#include <linux/inet.h>
#include <linux/module.h>
#include <keys/user-type.h>
#include <net/ipv6.h>
#include <linux/parser.h>
#include <linux/bvec.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "ntlmssp.h"
#include "nterr.h"
#include "rfc1002pdu.h"
#include "fscache.h"
#include "smb2proto.h"
#include "smbdirect.h"
#include "dns_resolve.h"
#ifdef CONFIG_CIFS_DFS_UPCALL
#include "dfs_cache.h"
#endif
#include "fs_context.h"
#include "cifs_swn.h"
extern mempool_t *cifs_req_poolp;
extern bool disable_legacy_dialects;
/* FIXME: should these be tunable? */
#define TLINK_ERROR_EXPIRE (1 * HZ)
#define TLINK_IDLE_EXPIRE (600 * HZ)
/* Drop the connection to not overload the server */
#define NUM_STATUS_IO_TIMEOUT 5
struct mount_ctx {
struct cifs_sb_info *cifs_sb;
struct smb3_fs_context *fs_ctx;
unsigned int xid;
struct TCP_Server_Info *server;
struct cifs_ses *ses;
struct cifs_tcon *tcon;
#ifdef CONFIG_CIFS_DFS_UPCALL
struct cifs_ses *root_ses;
uuid_t mount_id;
char *origin_fullpath, *leaf_fullpath;
#endif
};
static int ip_connect(struct TCP_Server_Info *server);
static int generic_ip_connect(struct TCP_Server_Info *server);
static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
static void cifs_prune_tlinks(struct work_struct *work);
/*
* Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
* get their ip addresses changed at some point.
*
* This should be called with server->srv_mutex held.
*/
static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
{
int rc;
int len;
char *unc, *ipaddr = NULL;
time64_t expiry, now;
unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
if (!server->hostname)
return -EINVAL;
/* if server hostname isn't populated, there's nothing to do here */
if (server->hostname[0] == '\0')
return 0;
len = strlen(server->hostname) + 3;
unc = kmalloc(len, GFP_KERNEL);
if (!unc) {
cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
return -ENOMEM;
}
scnprintf(unc, len, "\\\\%s", server->hostname);
rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
kfree(unc);
if (rc < 0) {
cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
__func__, server->hostname, rc);
goto requeue_resolve;
}
spin_lock(&server->srv_lock);
rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
strlen(ipaddr));
spin_unlock(&server->srv_lock);
kfree(ipaddr);
/* rc == 1 means success here */
if (rc) {
now = ktime_get_real_seconds();
if (expiry && expiry > now)
/*
* To make sure we don't use the cached entry, retry 1s
* after expiry.
*/
ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
}
rc = !rc ? -1 : 0;
requeue_resolve:
cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
__func__, ttl);
mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
return rc;
}
static void smb2_query_server_interfaces(struct work_struct *work)
{
int rc;
struct cifs_tcon *tcon = container_of(work,
struct cifs_tcon,
query_interfaces.work);
/*
* query server network interfaces, in case they change
*/
rc = SMB3_request_interfaces(0, tcon, false);
if (rc) {
cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
__func__, rc);
}
queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
(SMB_INTERFACE_POLL_INTERVAL * HZ));
}
static void cifs_resolve_server(struct work_struct *work)
{
int rc;
struct TCP_Server_Info *server = container_of(work,
struct TCP_Server_Info, resolve.work);
cifs_server_lock(server);
/*
* Resolve the hostname again to make sure that IP address is up-to-date.
*/
rc = reconn_set_ipaddr_from_hostname(server);
if (rc) {
cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
__func__, rc);
}
cifs_server_unlock(server);
}
/*
* Update the tcpStatus for the server.
* This is used to signal the cifsd thread to call cifs_reconnect
* ONLY cifsd thread should call cifs_reconnect. For any other
* thread, use this function
*
* @server: the tcp ses for which reconnect is needed
* @all_channels: if this needs to be done for all channels
*/
void
cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
bool all_channels)
{
struct TCP_Server_Info *pserver;
struct cifs_ses *ses;
int i;
/* If server is a channel, select the primary channel */
pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
spin_lock(&pserver->srv_lock);
if (!all_channels) {
pserver->tcpStatus = CifsNeedReconnect;
spin_unlock(&pserver->srv_lock);
return;
}
spin_unlock(&pserver->srv_lock);
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
spin_lock(&ses->chan_lock);
for (i = 0; i < ses->chan_count; i++) {
spin_lock(&ses->chans[i].server->srv_lock);
ses->chans[i].server->tcpStatus = CifsNeedReconnect;
spin_unlock(&ses->chans[i].server->srv_lock);
}
spin_unlock(&ses->chan_lock);
}
spin_unlock(&cifs_tcp_ses_lock);
}
/*
* Mark all sessions and tcons for reconnect.
* IMPORTANT: make sure that this gets called only from
* cifsd thread. For any other thread, use
* cifs_signal_cifsd_for_reconnect
*
* @server: the tcp ses for which reconnect is needed
* @server needs to be previously set to CifsNeedReconnect.
* @mark_smb_session: whether even sessions need to be marked
*/
void
cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
bool mark_smb_session)
{
struct TCP_Server_Info *pserver;
struct cifs_ses *ses, *nses;
struct cifs_tcon *tcon;
/*
* before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
* are not used until reconnected.
*/
cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
/* If server is a channel, select the primary channel */
pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
/* check if iface is still active */
if (!cifs_chan_is_iface_active(ses, server))
cifs_chan_update_iface(ses, server);
spin_lock(&ses->chan_lock);
if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
goto next_session;
if (mark_smb_session)
CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
else
cifs_chan_set_need_reconnect(ses, server);
/* If all channels need reconnect, then tcon needs reconnect */
if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
goto next_session;
ses->ses_status = SES_NEED_RECON;
list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
tcon->need_reconnect = true;
tcon->status = TID_NEED_RECON;
}
if (ses->tcon_ipc)
ses->tcon_ipc->need_reconnect = true;
next_session:
spin_unlock(&ses->chan_lock);
}
spin_unlock(&cifs_tcp_ses_lock);
}
static void
cifs_abort_connection(struct TCP_Server_Info *server)
{
struct mid_q_entry *mid, *nmid;
struct list_head retry_list;
server->maxBuf = 0;
server->max_read = 0;
/* do not want to be sending data on a socket we are freeing */
cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
cifs_server_lock(server);
if (server->ssocket) {
cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
server->ssocket->flags);
kernel_sock_shutdown(server->ssocket, SHUT_WR);
cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
server->ssocket->flags);
sock_release(server->ssocket);
server->ssocket = NULL;
}
server->sequence_number = 0;
server->session_estab = false;
kfree_sensitive(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
server->lstrp = jiffies;
/* mark submitted MIDs for retry and issue callback */
INIT_LIST_HEAD(&retry_list);
cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
spin_lock(&server->mid_lock);
list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
kref_get(&mid->refcount);
if (mid->mid_state == MID_REQUEST_SUBMITTED)
mid->mid_state = MID_RETRY_NEEDED;
list_move(&mid->qhead, &retry_list);
mid->mid_flags |= MID_DELETED;
}
spin_unlock(&server->mid_lock);
cifs_server_unlock(server);
cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
list_del_init(&mid->qhead);
mid->callback(mid);
release_mid(mid);
}
if (cifs_rdma_enabled(server)) {
cifs_server_lock(server);
smbd_destroy(server);
cifs_server_unlock(server);
}
}
static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
{
spin_lock(&server->srv_lock);
server->nr_targets = num_targets;
if (server->tcpStatus == CifsExiting) {
/* the demux thread will exit normally next time through the loop */
spin_unlock(&server->srv_lock);
wake_up(&server->response_q);
return false;
}
cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
trace_smb3_reconnect(server->CurrentMid, server->conn_id,
server->hostname);
server->tcpStatus = CifsNeedReconnect;
spin_unlock(&server->srv_lock);
return true;
}
/*
* cifs tcp session reconnection
*
* mark tcp session as reconnecting so temporarily locked
* mark all smb sessions as reconnecting for tcp session
* reconnect tcp session
* wake up waiters on reconnection? - (not needed currently)
*
* if mark_smb_session is passed as true, unconditionally mark
* the smb session (and tcon) for reconnect as well. This value
* doesn't really matter for non-multichannel scenario.
*
*/
static int __cifs_reconnect(struct TCP_Server_Info *server,
bool mark_smb_session)
{
int rc = 0;
if (!cifs_tcp_ses_needs_reconnect(server, 1))
return 0;
cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
cifs_abort_connection(server);
do {
try_to_freeze();
cifs_server_lock(server);
if (!cifs_swn_set_server_dstaddr(server)) {
/* resolve the hostname again to make sure that IP address is up-to-date */
rc = reconn_set_ipaddr_from_hostname(server);
cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
}
if (cifs_rdma_enabled(server))
rc = smbd_reconnect(server);
else
rc = generic_ip_connect(server);
if (rc) {
cifs_server_unlock(server);
cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
msleep(3000);
} else {
atomic_inc(&tcpSesReconnectCount);
set_credits(server, 1);
spin_lock(&server->srv_lock);
if (server->tcpStatus != CifsExiting)
server->tcpStatus = CifsNeedNegotiate;
spin_unlock(&server->srv_lock);
cifs_swn_reset_server_dstaddr(server);
cifs_server_unlock(server);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
}
} while (server->tcpStatus == CifsNeedReconnect);
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsNeedNegotiate)
mod_delayed_work(cifsiod_wq, &server->echo, 0);
spin_unlock(&server->srv_lock);
wake_up(&server->response_q);
return rc;
}
#ifdef CONFIG_CIFS_DFS_UPCALL
static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
{
int rc;
char *hostname;
if (!cifs_swn_set_server_dstaddr(server)) {
if (server->hostname != target) {
hostname = extract_hostname(target);
if (!IS_ERR(hostname)) {
kfree(server->hostname);
server->hostname = hostname;
} else {
cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
__func__, PTR_ERR(hostname));
cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
server->hostname);
}
}
/* resolve the hostname again to make sure that IP address is up-to-date. */
rc = reconn_set_ipaddr_from_hostname(server);
cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
}
/* Reconnect the socket */
if (cifs_rdma_enabled(server))
rc = smbd_reconnect(server);
else
rc = generic_ip_connect(server);
return rc;
}
static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
struct dfs_cache_tgt_iterator **target_hint)
{
int rc;
struct dfs_cache_tgt_iterator *tit;
*target_hint = NULL;
/* If dfs target list is empty, then reconnect to last server */
tit = dfs_cache_get_tgt_iterator(tl);
if (!tit)
return __reconnect_target_unlocked(server, server->hostname);
/* Otherwise, try every dfs target in @tl */
for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
if (!rc) {
*target_hint = tit;
break;
}
}
return rc;
}
static int reconnect_dfs_server(struct TCP_Server_Info *server)
{
int rc = 0;
const char *refpath = server->current_fullpath + 1;
struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
struct dfs_cache_tgt_iterator *target_hint = NULL;
int num_targets = 0;
/*
* Determine the number of dfs targets the referral path in @cifs_sb resolves to.
*
* smb2_reconnect() needs to know how long it should wait based upon the number of dfs
* targets (server->nr_targets). It's also possible that the cached referral was cleared
* through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
* refreshing the referral, so, in this case, default it to 1.
*/
if (!dfs_cache_noreq_find(refpath, NULL, &tl))
num_targets = dfs_cache_get_nr_tgts(&tl);
if (!num_targets)
num_targets = 1;
if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
return 0;
/*
* Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
* different server or share during failover. It could be improved by adding some logic to
* only do that in case it connects to a different server or share, though.
*/
cifs_mark_tcp_ses_conns_for_reconnect(server, true);
cifs_abort_connection(server);
do {
try_to_freeze();
cifs_server_lock(server);
rc = reconnect_target_unlocked(server, &tl, &target_hint);
if (rc) {
/* Failed to reconnect socket */
cifs_server_unlock(server);
cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
msleep(3000);
continue;
}
/*
* Socket was created. Update tcp session status to CifsNeedNegotiate so that a
* process waiting for reconnect will know it needs to re-establish session and tcon
* through the reconnected target server.
*/
atomic_inc(&tcpSesReconnectCount);
set_credits(server, 1);
spin_lock(&server->srv_lock);
if (server->tcpStatus != CifsExiting)
server->tcpStatus = CifsNeedNegotiate;
spin_unlock(&server->srv_lock);
cifs_swn_reset_server_dstaddr(server);
cifs_server_unlock(server);
mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
} while (server->tcpStatus == CifsNeedReconnect);
if (target_hint)
dfs_cache_noreq_update_tgthint(refpath, target_hint);
dfs_cache_free_tgts(&tl);
/* Need to set up echo worker again once connection has been established */
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsNeedNegotiate)
mod_delayed_work(cifsiod_wq, &server->echo, 0);
spin_unlock(&server->srv_lock);
wake_up(&server->response_q);
return rc;
}
int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
{
/* If tcp session is not an dfs connection, then reconnect to last target server */
spin_lock(&server->srv_lock);
if (!server->is_dfs_conn) {
spin_unlock(&server->srv_lock);
return __cifs_reconnect(server, mark_smb_session);
}
spin_unlock(&server->srv_lock);
mutex_lock(&server->refpath_lock);
if (!server->origin_fullpath || !server->leaf_fullpath) {
mutex_unlock(&server->refpath_lock);
return __cifs_reconnect(server, mark_smb_session);
}
mutex_unlock(&server->refpath_lock);
return reconnect_dfs_server(server);
}
#else
int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
{
return __cifs_reconnect(server, mark_smb_session);
}
#endif
static void
cifs_echo_request(struct work_struct *work)
{
int rc;
struct TCP_Server_Info *server = container_of(work,
struct TCP_Server_Info, echo.work);
/*
* We cannot send an echo if it is disabled.
* Also, no need to ping if we got a response recently.
*/
if (server->tcpStatus == CifsNeedReconnect ||
server->tcpStatus == CifsExiting ||
server->tcpStatus == CifsNew ||
(server->ops->can_echo && !server->ops->can_echo(server)) ||
time_before(jiffies, server->lstrp + server->echo_interval - HZ))
goto requeue_echo;
rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
if (rc)
cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
server->hostname);
/* Check witness registrations */
cifs_swn_check();
requeue_echo:
queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
}
static bool
allocate_buffers(struct TCP_Server_Info *server)
{
if (!server->bigbuf) {
server->bigbuf = (char *)cifs_buf_get();
if (!server->bigbuf) {
cifs_server_dbg(VFS, "No memory for large SMB response\n");
msleep(3000);
/* retry will check if exiting */
return false;
}
} else if (server->large_buf) {
/* we are reusing a dirty large buf, clear its start */
memset(server->bigbuf, 0, HEADER_SIZE(server));
}
if (!server->smallbuf) {
server->smallbuf = (char *)cifs_small_buf_get();
if (!server->smallbuf) {
cifs_server_dbg(VFS, "No memory for SMB response\n");
msleep(1000);
/* retry will check if exiting */
return false;
}
/* beginning of smb buffer is cleared in our buf_get */
} else {
/* if existing small buf clear beginning */
memset(server->smallbuf, 0, HEADER_SIZE(server));
}
return true;
}
static bool
server_unresponsive(struct TCP_Server_Info *server)
{
/*
* We need to wait 3 echo intervals to make sure we handle such
* situations right:
* 1s client sends a normal SMB request
* 2s client gets a response
* 30s echo workqueue job pops, and decides we got a response recently
* and don't need to send another
* ...
* 65s kernel_recvmsg times out, and we see that we haven't gotten
* a response in >60s.
*/
spin_lock(&server->srv_lock);
if ((server->tcpStatus == CifsGood ||
server->tcpStatus == CifsNeedNegotiate) &&
(!server->ops->can_echo || server->ops->can_echo(server)) &&
time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
spin_unlock(&server->srv_lock);
cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
(3 * server->echo_interval) / HZ);
cifs_reconnect(server, false);
return true;
}
spin_unlock(&server->srv_lock);
return false;
}
static inline bool
zero_credits(struct TCP_Server_Info *server)
{
int val;
spin_lock(&server->req_lock);
val = server->credits + server->echo_credits + server->oplock_credits;
if (server->in_flight == 0 && val == 0) {
spin_unlock(&server->req_lock);
return true;
}
spin_unlock(&server->req_lock);
return false;
}
static int
cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
{
int length = 0;
int total_read;
for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
try_to_freeze();
/* reconnect if no credits and no requests in flight */
if (zero_credits(server)) {
cifs_reconnect(server, false);
return -ECONNABORTED;
}
if (server_unresponsive(server))
return -ECONNABORTED;
if (cifs_rdma_enabled(server) && server->smbd_conn)
length = smbd_recv(server->smbd_conn, smb_msg);
else
length = sock_recvmsg(server->ssocket, smb_msg, 0);
spin_lock(&server->srv_lock);
if (server->tcpStatus == CifsExiting) {
spin_unlock(&server->srv_lock);
return -ESHUTDOWN;
}
if (server->tcpStatus == CifsNeedReconnect) {
spin_unlock(&server->srv_lock);
cifs_reconnect(server, false);
return -ECONNABORTED;
}
spin_unlock(&server->srv_lock);
if (length == -ERESTARTSYS ||
length == -EAGAIN ||
length == -EINTR) {
/*
* Minimum sleep to prevent looping, allowing socket
* to clear and app threads to set tcpStatus
* CifsNeedReconnect if server hung.
*/
usleep_range(1000, 2000);
length = 0;
continue;
}
if (length <= 0) {
cifs_dbg(FYI, "Received no data or error: %d\n", length);
cifs_reconnect(server, false);
return -ECONNABORTED;
}
}
return total_read;
}
int
cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
unsigned int to_read)
{
struct msghdr smb_msg = {};
struct kvec iov = {.iov_base = buf, .iov_len = to_read};
iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
return cifs_readv_from_socket(server, &smb_msg);
}
ssize_t
cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
{
struct msghdr smb_msg = {};
/*
* iov_iter_discard already sets smb_msg.type and count and iov_offset
* and cifs_readv_from_socket sets msg_control and msg_controllen
* so little to initialize in struct msghdr
*/
iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
return cifs_readv_from_socket(server, &smb_msg);
}
int
cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
unsigned int page_offset, unsigned int to_read)
{
struct msghdr smb_msg = {};
struct bio_vec bv = {
.bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
return cifs_readv_from_socket(server, &smb_msg);
}
static bool
is_smb_response(struct TCP_Server_Info *server, unsigned char type)
{
/*
* The first byte big endian of the length field,
* is actually not part of the length but the type
* with the most common, zero, as regular data.
*/
switch (type) {
case RFC1002_SESSION_MESSAGE:
/* Regular SMB response */
return true;
case RFC1002_SESSION_KEEP_ALIVE:
cifs_dbg(FYI, "RFC 1002 session keep alive\n");
break;
case RFC1002_POSITIVE_SESSION_RESPONSE:
cifs_dbg(FYI, "RFC 1002 positive session response\n");
break;
case RFC1002_NEGATIVE_SESSION_RESPONSE:
/*
* We get this from Windows 98 instead of an error on
* SMB negprot response.
*/
cifs_dbg(FYI, "RFC 1002 negative session response\n");
/* give server a second to clean up */
msleep(1000);
/*
* Always try 445 first on reconnect since we get NACK
* on some if we ever connected to port 139 (the NACK
* is since we do not begin with RFC1001 session
* initialize frame).
*/
cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
cifs_reconnect(server, true);
break;
default:
cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
cifs_reconnect(server, true);
}
return false;
}
void
dequeue_mid(struct mid_q_entry *mid, bool malformed)
{
#ifdef CONFIG_CIFS_STATS2
mid->when_received = jiffies;
#endif
spin_lock(&mid->server->mid_lock);
if (!malformed)
mid->mid_state = MID_RESPONSE_RECEIVED;
else
mid->mid_state = MID_RESPONSE_MALFORMED;
/*
* Trying to handle/dequeue a mid after the send_recv()
* function has finished processing it is a bug.
*/
if (mid->mid_flags & MID_DELETED) {
spin_unlock(&mid->server->mid_lock);
pr_warn_once("trying to dequeue a deleted mid\n");
} else {
list_del_init(&mid->qhead);
mid->mid_flags |= MID_DELETED;
spin_unlock(&mid->server->mid_lock);
}
}
static unsigned int
smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
{
struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
/*
* SMB1 does not use credits.
*/
if (is_smb1(server))
return 0;
return le16_to_cpu(shdr->CreditRequest);
}
static void
handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
char *buf, int malformed)
{
if (server->ops->check_trans2 &&
server->ops->check_trans2(mid, server, buf, malformed))
return;
mid->credits_received = smb2_get_credits_from_hdr(buf, server);
mid->resp_buf = buf;
mid->large_buf = server->large_buf;
/* Was previous buf put in mpx struct for multi-rsp? */
if (!mid->multiRsp) {
/* smb buffer will be freed by user thread */
if (server->large_buf)
server->bigbuf = NULL;
else
server->smallbuf = NULL;
}
dequeue_mid(mid, malformed);
}
int
cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
{
bool srv_sign_required = server->sec_mode & server->vals->signing_required;
bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
bool mnt_sign_enabled;
/*
* Is signing required by mnt options? If not then check
* global_secflags to see if it is there.
*/
if (!mnt_sign_required)
mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
CIFSSEC_MUST_SIGN);
/*
* If signing is required then it's automatically enabled too,
* otherwise, check to see if the secflags allow it.
*/
mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
(global_secflags & CIFSSEC_MAY_SIGN);
/* If server requires signing, does client allow it? */
if (srv_sign_required) {
if (!mnt_sign_enabled) {
cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
return -EOPNOTSUPP;
}
server->sign = true;
}
/* If client requires signing, does server allow it? */
if (mnt_sign_required) {
if (!srv_sign_enabled) {
cifs_dbg(VFS, "Server does not support signing!\n");
return -EOPNOTSUPP;
}
server->sign = true;
}
if (cifs_rdma_enabled(server) && server->sign)
cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
return 0;
}
static void clean_demultiplex_info(struct TCP_Server_Info *server)
{
int length;
/* take it off the list, if it's not already */
spin_lock(&server->srv_lock);
list_del_init(&server->tcp_ses_list);
spin_unlock(&server->srv_lock);
cancel_delayed_work_sync(&server->echo);
cancel_delayed_work_sync(&server->resolve);
spin_lock(&server->srv_lock);
server->tcpStatus = CifsExiting;
spin_unlock(&server->srv_lock);
wake_up_all(&server->response_q);
/* check if we have blocked requests that need to free */
spin_lock(&server->req_lock);
if (server->credits <= 0)
server->credits = 1;
spin_unlock(&server->req_lock);
/*
* Although there should not be any requests blocked on this queue it
* can not hurt to be paranoid and try to wake up requests that may
* haven been blocked when more than 50 at time were on the wire to the
* same server - they now will see the session is in exit state and get
* out of SendReceive.
*/
wake_up_all(&server->request_q);
/* give those requests time to exit */
msleep(125);
if (cifs_rdma_enabled(server))
smbd_destroy(server);
if (server->ssocket) {
sock_release(server->ssocket);
server->ssocket = NULL;
}
if (!list_empty(&server->pending_mid_q)) {
struct list_head dispose_list;
struct mid_q_entry *mid_entry;
struct list_head *tmp, *tmp2;
INIT_LIST_HEAD(&dispose_list);
spin_lock(&server->mid_lock);
list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
kref_get(&mid_entry->refcount);
mid_entry->mid_state = MID_SHUTDOWN;
list_move(&mid_entry->qhead, &dispose_list);
mid_entry->mid_flags |= MID_DELETED;
}
spin_unlock(&server->mid_lock);
/* now walk dispose list and issue callbacks */
list_for_each_safe(tmp, tmp2, &dispose_list) {