diff options
Diffstat (limited to 'fs/smb/client/connect.c')
| -rw-r--r-- | fs/smb/client/connect.c | 4835 |
1 files changed, 4835 insertions, 0 deletions
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c new file mode 100644 index 000000000..49fdc6dfd --- /dev/null +++ b/fs/smb/client/connect.c @@ -0,0 +1,4835 @@ +// 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 MAX_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; + + /* if we need to signal just this channel */ + if (!all_channels) { + spin_lock(&server->srv_lock); + if (server->tcpStatus != CifsExiting) + server->tcpStatus = CifsNeedReconnect; + spin_unlock(&server->srv_lock); + return; + } + + 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 */ + spin_lock(&ses->chan_lock); + if (!cifs_chan_is_iface_active(ses, server)) { + spin_unlock(&ses->chan_lock); + cifs_chan_update_iface(ses, server); + spin_lock(&ses->chan_lock); + } + + if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) { + spin_unlock(&ses->chan_lock); + continue; + } + + if (mark_smb_session) + CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses); + else + cifs_chan_set_need_reconnect(ses, server); + + cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n", + __func__, ses->chans_need_reconnect); + + /* If all channels need reconnect, then tcon needs reconnect */ + if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) { + spin_unlock(&ses->chan_lock); + continue; + } + spin_unlock(&ses->chan_lock); + + spin_lock(&ses->ses_lock); + ses->ses_status = SES_NEED_RECON; + spin_unlock(&ses->ses_lock); + + list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { + tcon->need_reconnect = true; + spin_lock(&tcon->tc_lock); + tcon->status = TID_NEED_RECON; + spin_unlock(&tcon->tc_lock); + } + if (ses->tcon_ipc) { + ses->tcon_ipc->need_reconnect = true; + spin_lock(&ses->tcon_ipc->tc_lock); + ses->tcon_ipc->status = TID_NEED_RECON; + spin_unlock(&ses->tcon_ipc->tc_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)) { + spin_lock(&server->srv_lock); + kfree(server->hostname); + server->hostname = hostname; + spin_unlock(&server->srv_lock); + } 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; + cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc); + + /* 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, ITER_DEST, &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, ITER_DEST, 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, ITER_DEST, &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; + bool pending_reconnect = false; + + 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; + + pending_reconnect = false; +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) { + if (server->ops->next_header(server, buf, &next_offset)) { + cifs_dbg(VFS, "%s: malformed response (next_offset=%u)\n", + __func__, next_offset); + cifs_reconnect(server, true); + continue; + } + 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 > MAX_STATUS_IO_TIMEOUT) { + cifs_server_dbg(VFS, + "Number of request timeouts exceeded %d. Reconnecting", + MAX_STATUS_IO_TIMEOUT); + + pending_reconnect = true; + num_io_timeout = 0; + } + } + + 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; + } + + /* do this reconnect at the very end after processing all MIDs */ + if (pending_reconnect) + cifs_reconnect(server, true); + + } /* 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); +} + +int +cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs) +{ + struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr; + struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs; + struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr; + struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs; + + switch (srcaddr->sa_family) { + case AF_UNSPEC: + switch (rhs->sa_family) { + case AF_UNSPEC: + return 0; + case AF_INET: + case AF_INET6: + return 1; + default: + return -1; + } + case AF_INET: { + switch (rhs->sa_family) { + case AF_UNSPEC: + return -1; + case AF_INET: + return memcmp(saddr4, vaddr4, + sizeof(struct sockaddr_in)); + case AF_INET6: + return 1; + default: + return -1; + } + } + case AF_INET6: { + switch (rhs->sa_family) { + case AF_UNSPEC: + case AF_INET: + return -1; + case AF_INET6: + return memcmp(saddr6, + vaddr6, + sizeof(struct sockaddr_in6)); + default: + return -1; + } + } + default: + return -1; /* don't expect to be here */ + } +} + +/* + * 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; + + lockdep_assert_held(&server->srv_lock); + + if (ctx->nosharesock) + return 0; + + /* this server does not share socket */ + if (server->nosharesock) + return 0; + + /* If multidialect negotiation see if existing sessions match one */ + if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) { + if (server->vals->protocol_id < SMB30_PROT_ID) + return 0; + } else if (strcmp(ctx->vals->version_string, + SMBDEFAULT_VERSION_STRING) == 0) { + if (server->vals->protocol_id < SMB21_PROT_ID) + return 0; + } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops)) + return 0; + + if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns)) + return 0; + + if (strcasecmp(server->hostname, ctx->server_hostname)) + return 0; + + if (!match_address(server, addr, + (struct sockaddr *)&ctx->srcaddr)) + return 0; + + if (!match_port(server, addr)) + return 0; + + if (!match_security(server, ctx)) + return 0; + + if (server->echo_interval != ctx->echo_interval * HZ) + return 0; + + if (server->rdma != ctx->rdma) + return 0; + + if (server->ignore_signature != ctx->ignore_signature) + return 0; + + if (server->min_offload != ctx->min_offload) + return 0; + + return 1; +} + +struct TCP_Server_Info * +cifs_find_tcp_session(struct smb3_fs_context *ctx) +{ + struct TCP_Server_Info *server; + + spin_lock(&cifs_tcp_ses_lock); + list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { + spin_lock(&server->srv_lock); +#ifdef CONFIG_CIFS_DFS_UPCALL + /* + * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for + * DFS connections to do failover properly, so avoid sharing them with regular + * shares or even links that may connect to same server but having completely + * different failover targets. + */ + if (server->is_dfs_conn) { + spin_unlock(&server->srv_lock); + continue; + } +#endif + /* + * Skip ses channels since they're only handled in lower layers + * (e.g. cifs_send_recv). + */ + if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) { + spin_unlock(&server->srv_lock); + continue; + } + spin_unlock(&server->srv_lock); + + ++server->srv_count; + spin_unlock(&cifs_tcp_ses_lock); + cifs_dbg(FYI, "Existing tcp session with server found\n"); + return server; + } + spin_unlock(&cifs_tcp_ses_lock); + return NULL; +} + +void +cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect) +{ + struct task_struct *task; + + spin_lock(&cifs_tcp_ses_lock); + if (--server->srv_count > 0) { + spin_unlock(&cifs_tcp_ses_lock); + return; + } + + /* srv_count can never go negative */ + WARN_ON(server->srv_count < 0); + + put_net(cifs_net_ns(server)); + + list_del_init(&server->tcp_ses_list); + spin_unlock(&cifs_tcp_ses_lock); + + /* For secondary channels, we pick up ref-count on the primary server */ + if (CIFS_SERVER_IS_CHAN(server)) + cifs_put_tcp_session(server->primary_server, from_reconnect); + + cancel_delayed_work_sync(&server->echo); + cancel_delayed_work_sync(&server->resolve); + + if (from_reconnect) + /* + * Avoid deadlock here: reconnect work calls + * cifs_put_tcp_session() at its end. Need to be sure + * that reconnect work does nothing with server pointer after + * that step. + */ + cancel_delayed_work(&server->reconnect); + else + cancel_delayed_work_sync(&server->reconnect); + + spin_lock(&server->srv_lock); + server->tcpStatus = CifsExiting; + spin_unlock(&server->srv_lock); + + cifs_crypto_secmech_release(server); + + kfree_sensitive(server->session_key.response); + server->session_key.response = NULL; + server->session_key.len = 0; + kfree(server->hostname); + server->hostname = NULL; + + task = xchg(&server->tsk, NULL); + if (task) + send_sig(SIGKILL, task, 1); +} + +struct TCP_Server_Info * +cifs_get_tcp_session(struct smb3_fs_context *ctx, + struct TCP_Server_Info *primary_server) +{ + struct TCP_Server_Info *tcp_ses = NULL; + int rc; + + cifs_dbg(FYI, "UNC: %s\n", ctx->UNC); + + /* see if we already have a matching tcp_ses */ + tcp_ses = cifs_find_tcp_session(ctx); + if (tcp_ses) + return tcp_ses; + + tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL); + if (!tcp_ses) { + rc = -ENOMEM; + goto out_err; + } + + tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL); + if (!tcp_ses->hostname) { + rc = -ENOMEM; + goto out_err; + } + + if (ctx->nosharesock) + tcp_ses->nosharesock = true; + + tcp_ses->ops = ctx->ops; + tcp_ses->vals = ctx->vals; + cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns)); + + tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId); + tcp_ses->noblockcnt = ctx->rootfs; + tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs; + tcp_ses->noautotune = ctx->noautotune; + tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay; + tcp_ses->rdma = ctx->rdma; + tcp_ses->in_flight = 0; + tcp_ses->max_in_flight = 0; + tcp_ses->credits = 1; + if (primary_server) { + spin_lock(&cifs_tcp_ses_lock); + ++primary_server->srv_count; + spin_unlock(&cifs_tcp_ses_lock); + tcp_ses->primary_server = primary_server; + } + init_waitqueue_head(&tcp_ses->response_q); + init_waitqueue_head(&tcp_ses->request_q); + INIT_LIST_HEAD(&tcp_ses->pending_mid_q); + mutex_init(&tcp_ses->_srv_mutex); + memcpy(tcp_ses->workstation_RFC1001_name, + ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL); + memcpy(tcp_ses->server_RFC1001_name, + ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL); + tcp_ses->session_estab = false; + tcp_ses->sequence_number = 0; + tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */ + 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 and chan_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 + */ + if (ses->chan_max < ctx->max_channels) + return 0; + + 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$")] = {0}; + bool seal = false; + struct TCP_Server_Info *server = ses->server; + + /* + * If the mount request that resulted in the creation of the + * session requires encryption, force IPC to be encrypted too. + */ + if (ctx->seal) { + if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) + seal = true; + else { + cifs_server_dbg(VFS, + "IPC: server doesn't support encryption\n"); + return -EOPNOTSUPP; + } + } + + tcon = tconInfoAlloc(); + if (tcon == NULL) + return -ENOMEM; + + spin_lock(&server->srv_lock); + scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname); + spin_unlock(&server->srv_lock); + + 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); + + spin_lock(&tcon->tc_lock); + tcon->status = TID_GOOD; + spin_unlock(&tcon->tc_lock); + 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; + } + spin_lock(&ses->chan_lock); + if (!match_session(ses, ctx)) { + spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); + continue; + } + spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); + + ++ses->ses_count; + spin_unlock(&cifs_tcp_ses_lock); + return ses; + } + spin_unlock(&cifs_tcp_ses_lock); + return NULL; +} + +void cifs_put_smb_ses(struct cifs_ses *ses) +{ + unsigned int rc, xid; + unsigned int chan_count; + struct TCP_Server_Info *server = ses->server; + + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + return; + } + spin_unlock(&ses->ses_lock); + + cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); + cifs_dbg(FYI, + "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE"); + + spin_lock(&cifs_tcp_ses_lock); + if (--ses->ses_count > 0) { + spin_unlock(&cifs_tcp_ses_lock); + return; + } + spin_unlock(&cifs_tcp_ses_lock); + + /* ses_count can never go negative */ + WARN_ON(ses->ses_count < 0); + + if (ses->ses_status == SES_GOOD) + ses->ses_status = SES_EXITING; + + cifs_free_ipc(ses); + + if (ses->ses_status == SES_EXITING && server->ops->logoff) { + xid = get_xid(); + rc = server->ops->logoff(xid, ses); + if (rc) + cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n", + __func__, rc); + _free_xid(xid); + } + + spin_lock(&cifs_tcp_ses_lock); + list_del_init(&ses->smb_ses_list); + spin_unlock(&cifs_tcp_ses_lock); + + chan_count = ses->chan_count; + + /* close any extra channels */ + if (chan_count > 1) { + int i; + + for (i = 1; i < chan_count; i++) { + if (ses->chans[i].iface) { + kref_put(&ses->chans[i].iface->refcount, release_iface); + ses->chans[i].iface = NULL; + } + cifs_put_tcp_session(ses->chans[i].server, 0); + ses->chans[i].server = NULL; + } + } + + /* we now account for primary channel in iface->refcount */ + if (ses->chans[0].iface) { + kref_put(&ses->chans[0].iface->refcount, release_iface); + ses->chans[0].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 = 0; + 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; + } + + rc = -ENOMEM; + + 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); + + cifs_setup_ipc(ses, ctx); + + free_xid(xid); + + return ses; + +get_ses_fail: + sesInfoFree(ses); + free_xid(xid); + return ERR_PTR(rc); +} + +/* this function must be called with tc_lock held */ +static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx) +{ + if (tcon->status == TID_EXITING) + return 0; + if (strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) + return 0; + if (tcon->seal != ctx->seal) + return 0; + if (tcon->snapshot_time != ctx->snapshot_time) + return 0; + if (tcon->handle_timeout != ctx->handle_timeout) + return 0; + if (tcon->no_lease != ctx->no_lease) + return 0; + if (tcon->nodelete != ctx->nodelete) + return 0; + return 1; +} + +static struct cifs_tcon * +cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx) +{ + struct cifs_tcon *tcon; + + spin_lock(&cifs_tcp_ses_lock); + list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { + spin_lock(&tcon->tc_lock); + if (!match_tcon(tcon, ctx)) { + spin_unlock(&tcon->tc_lock); + continue; + } + ++tcon->tc_count; + spin_unlock(&tcon->tc_lock); + spin_unlock(&cifs_tcp_ses_lock); + return tcon; + } + spin_unlock(&cifs_tcp_ses_lock); + return NULL; +} + +void +cifs_put_tcon(struct cifs_tcon *tcon) +{ + unsigned int xid; + struct cifs_ses *ses; + + /* + * IPC tcon share the lifetime of their session and are + * destroyed in the session put function + */ + if (tcon == NULL || tcon->ipc) + return; + + ses = tcon->ses; + cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count); + spin_lock(&cifs_tcp_ses_lock); + spin_lock(&tcon->tc_lock); + if (--tcon->tc_count > 0) { + spin_unlock(&tcon->tc_lock); + spin_unlock(&cifs_tcp_ses_lock); + return; + } + + /* tc_count can never go negative */ + WARN_ON(tcon->tc_count < 0); + + list_del_init(&tcon->tcon_list); + tcon->status = TID_EXITING; + spin_unlock(&tcon->tc_lock); + spin_unlock(&cifs_tcp_ses_lock); + + /* cancel polling of interfaces */ + cancel_delayed_work_sync(&tcon->query_interfaces); + + if (tcon->use_witness) { + int rc; + + rc = cifs_swn_unregister(tcon); + if (rc < 0) { + cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n", + __func__, rc); + } + } + + xid = get_xid(); + if (ses->server->ops->tree_disconnect) + ses->server->ops->tree_disconnect(xid, tcon); + _free_xid(xid); + + cifs_fscache_release_super_cookie(tcon); + tconInfoFree(tcon); + cifs_put_smb_ses(ses); +} + +/** + * cifs_get_tcon - get a tcon matching @ctx data from @ses + * @ses: smb session to issue the request on + * @ctx: the superblock configuration context to use for building the + * + * - tcon refcount is the number of mount points using the tcon. + * - ses refcount is the number of tcon using the session. + * + * 1. This function assumes it is being called from cifs_mount() where + * we already got a session reference (ses refcount +1). + * + * 2. Since we're in the context of adding a mount point, the end + * result should be either: + * + * a) a new tcon already allocated with refcount=1 (1 mount point) and + * its session refcount incremented (1 new tcon). This +1 was + * already done in (1). + * + * b) an existing tcon with refcount+1 (add a mount point to it) and + * identical ses refcount (no new tcon). Because of (1) we need to + * decrement the ses refcount. + */ +static struct cifs_tcon * +cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx) +{ + int rc, xid; + struct cifs_tcon *tcon; + + tcon = cifs_find_tcon(ses, ctx); + if (tcon) { + /* + * tcon has refcount already incremented but we need to + * decrement extra ses reference gotten by caller (case b) + */ + cifs_dbg(FYI, "Found match on UNC path\n"); + cifs_put_smb_ses(ses); + return tcon; + } + + if (!ses->server->ops->tree_connect) { + rc = -ENOSYS; + goto out_fail; + } + + tcon = tconInfoAlloc(); + if (tcon == NULL) { + rc = -ENOMEM; + goto out_fail; + } + + if (ctx->snapshot_time) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "Use SMB2 or later for snapshot mount option\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } else + tcon->snapshot_time = ctx->snapshot_time; + } + + if (ctx->handle_timeout) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "Use SMB2.1 or later for handle timeout option\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } else + tcon->handle_timeout = ctx->handle_timeout; + } + + tcon->ses = ses; + if (ctx->password) { + tcon->password = kstrdup(ctx->password, GFP_KERNEL); + if (!tcon->password) { + rc = -ENOMEM; + goto out_fail; + } + } + + if (ctx->seal) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "SMB3 or later required for encryption\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } else if (tcon->ses->server->capabilities & + SMB2_GLOBAL_CAP_ENCRYPTION) + tcon->seal = true; + else { + cifs_dbg(VFS, "Encryption is not supported on share\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } + } + + if (ctx->linux_ext) { + if (ses->server->posix_ext_supported) { + tcon->posix_extensions = true; + pr_warn_once("SMB3.11 POSIX Extensions are experimental\n"); + } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) || + (strcmp(ses->server->vals->version_string, + SMB3ANY_VERSION_STRING) == 0) || + (strcmp(ses->server->vals->version_string, + SMBDEFAULT_VERSION_STRING) == 0)) { + cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } else { + cifs_dbg(VFS, "Check vers= mount option. SMB3.11 " + "disabled but required for POSIX extensions\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } + } + + xid = get_xid(); + rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon, + ctx->local_nls); + free_xid(xid); + cifs_dbg(FYI, "Tcon rc = %d\n", rc); + if (rc) + goto out_fail; + + tcon->use_persistent = false; + /* check if SMB2 or later, CIFS does not support persistent handles */ + if (ctx->persistent) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "SMB3 or later required for persistent handles\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } else if (ses->server->capabilities & + SMB2_GLOBAL_CAP_PERSISTENT_HANDLES) + tcon->use_persistent = true; + else /* persistent handles requested but not supported */ { + cifs_dbg(VFS, + "Persistent handles not supported on share\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } + } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY) + && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES) + && (ctx->nopersistent == false)) { + cifs_dbg(FYI, "enabling persistent handles\n"); + tcon->use_persistent = true; + } else if (ctx->resilient) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "SMB2.1 or later required for resilient handles\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } + tcon->use_resilient = true; + } + + tcon->use_witness = false; + if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) { + if (ses->server->vals->protocol_id >= SMB30_PROT_ID) { + if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) { + /* + * Set witness in use flag in first place + * to retry registration in the echo task + */ + tcon->use_witness = true; + /* And try to register immediately */ + rc = cifs_swn_register(tcon); + if (rc < 0) { + cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc); + goto out_fail; + } + } else { + /* TODO: try to extend for non-cluster uses (eg multichannel) */ + cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } + } else { + cifs_dbg(VFS, "SMB3 or later required for witness option\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } + } + + /* If the user really knows what they are doing they can override */ + if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) { + if (ctx->cache_ro) + cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n"); + else if (ctx->cache_rw) + cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n"); + } + + if (ctx->no_lease) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "SMB2 or later required for nolease option\n"); + rc = -EOPNOTSUPP; + goto out_fail; + } else + tcon->no_lease = ctx->no_lease; + } + + /* + * We can have only one retry value for a connection to a share so for + * resources mounted more than once to the same server share the last + * value passed in for the retry flag is used. + */ + tcon->retry = ctx->retry; + tcon->nocase = ctx->nocase; + tcon->broken_sparse_sup = ctx->no_sparse; + if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING) + tcon->nohandlecache = ctx->nohandlecache; + else + tcon->nohandlecache = true; + tcon->nodelete = ctx->nodelete; + tcon->local_lease = ctx->local_lease; + INIT_LIST_HEAD(&tcon->pending_opens); + tcon->status = TID_GOOD; + + INIT_DELAYED_WORK(&tcon->query_interfaces, + smb2_query_server_interfaces); + if (ses->server->dialect >= SMB30_PROT_ID && + (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) { + /* schedule query interfaces poll */ + 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); + + /* We do not want to use a superblock that has been shutdown */ + if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) { + spin_unlock(&cifs_tcp_ses_lock); + return 0; + } + + 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(&ses->chan_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->chan_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 = kernel_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 req = {}; + struct smb_hdr *smb_buf = (struct smb_hdr *)&req; + unsigned int len; + + req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name); + + if (server->server_RFC1001_name[0] != 0) + rfc1002mangle(req.trailer.session_req.called_name, + server->server_RFC1001_name, + RFC1001_NAME_LEN_WITH_NULL); + else + rfc1002mangle(req.trailer.session_req.called_name, + DEFAULT_CIFS_CALLED_NAME, + RFC1001_NAME_LEN_WITH_NULL); + + req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name); + + /* calling name ends in null (byte 16) from old smb convention */ + if (server->workstation_RFC1001_name[0] != 0) + rfc1002mangle(req.trailer.session_req.calling_name, + server->workstation_RFC1001_name, + RFC1001_NAME_LEN_WITH_NULL); + else + rfc1002mangle(req.trailer.session_req.calling_name, + "LINUX_CIFS_CLNT", + RFC1001_NAME_LEN_WITH_NULL); + + /* + * As per rfc1002, @len must be the number of bytes that follows the + * length field of a rfc1002 session request payload. + */ + len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req); + + smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len); + rc = smb_send(server, smb_buf, len); + /* + * 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); + + 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 = kernel_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; + + 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); + if (rc != 0 && rc != -EREMOTE) + goto out; + + if (rc != -EREMOTE) { + rc = cifs_are_all_path_components_accessible(server, xid, tcon, + cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS); + if (rc != 0) { + cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n"); + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; + rc = 0; + } + } + +out: + kfree(full_path); + return rc; +} + +#ifdef CONFIG_CIFS_DFS_UPCALL +static void set_root_ses(struct mount_ctx *mnt_ctx) +{ + if (mnt_ctx->ses) { + spin_lock(&cifs_tcp_ses_lock); + mnt_ctx->ses->ses_count++; + spin_unlock(&cifs_tcp_ses_lock); + dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses); + } + mnt_ctx->root_ses = mnt_ctx->ses; +} + +static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl) +{ + int rc; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + + *isdfs = true; + + rc = mount_get_conns(mnt_ctx); + /* + * If called with 'nodfs' mount option, then skip DFS resolving. Otherwise unconditionally + * try to get an DFS referral (even cached) to determine whether it is an DFS mount. + * + * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem + * to respond with PATH_NOT_COVERED to requests that include the prefix. + */ + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) || + dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), + ctx->UNC + 1, NULL, root_tl)) { + if (rc) + return rc; + /* Check if it is fully accessible and then mount it */ + rc = is_path_remote(mnt_ctx); + if (!rc) + *isdfs = false; + else if (rc != -EREMOTE) + return rc; + } + return 0; +} + +static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path, + const char *ref_path, struct dfs_cache_tgt_iterator *tit) +{ + int rc; + struct dfs_info3_param ref = {}; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + char *oldmnt = cifs_sb->ctx->mount_options; + + cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path, + dfs_cache_get_tgt_name(tit)); + + rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref); + if (rc) + goto out; + + rc = expand_dfs_referral(mnt_ctx, full_path, &ref); + if (rc) + goto out; + + /* Connect to new target only if we were redirected (e.g. mount options changed) */ + if (oldmnt != cifs_sb->ctx->mount_options) { + mount_put_conns(mnt_ctx); + rc = mount_get_dfs_conns(mnt_ctx); + } + if (!rc) { + if (cifs_is_referral_server(mnt_ctx->tcon, &ref)) + set_root_ses(mnt_ctx); + rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls, + cifs_remap(cifs_sb), ref_path, tit); + } + +out: + free_dfs_info_param(&ref); + return rc; +} + +static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl) +{ + int rc; + char *full_path; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + struct dfs_cache_tgt_iterator *tit; + + /* Put initial connections as they might be shared with other mounts. We need unique dfs + * connections per mount to properly failover, so mount_get_dfs_conns() must be used from + * now on. + */ + mount_put_conns(mnt_ctx); + mount_get_dfs_conns(mnt_ctx); + set_root_ses(mnt_ctx); + + full_path = build_unc_path_to_root(ctx, cifs_sb, true); + if (IS_ERR(full_path)) + return PTR_ERR(full_path); + + mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls, + cifs_remap(cifs_sb)); + if (IS_ERR(mnt_ctx->origin_fullpath)) { + rc = PTR_ERR(mnt_ctx->origin_fullpath); + mnt_ctx->origin_fullpath = NULL; + goto out; + } + + /* Try all dfs root targets */ + for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl); + tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) { + rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit); + if (!rc) { + mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL); + if (!mnt_ctx->leaf_fullpath) + rc = -ENOMEM; + break; + } + } + +out: + kfree(full_path); + return rc; +} + +static int __follow_dfs_link(struct mount_ctx *mnt_ctx) +{ + int rc; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + char *full_path; + struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl); + struct dfs_cache_tgt_iterator *tit; + + full_path = build_unc_path_to_root(ctx, cifs_sb, true); + if (IS_ERR(full_path)) + return PTR_ERR(full_path); + + kfree(mnt_ctx->leaf_fullpath); + mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls, + cifs_remap(cifs_sb)); + if (IS_ERR(mnt_ctx->leaf_fullpath)) { + rc = PTR_ERR(mnt_ctx->leaf_fullpath); + mnt_ctx->leaf_fullpath = NULL; + goto out; + } + + /* Get referral from dfs link */ + rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls, + cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl); + if (rc) + goto out; + + /* Try all dfs link targets. If an I/O fails from currently connected DFS target with an + * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as + * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than + * STATUS_PATH_NOT_COVERED." + */ + for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl); + tit; tit = dfs_cache_get_next_tgt(&tl, tit)) { + rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit); + if (!rc) { + rc = is_path_remote(mnt_ctx); + if (!rc || rc == -EREMOTE) + break; + } + } + +out: + kfree(full_path); + dfs_cache_free_tgts(&tl); + return rc; +} + +static int follow_dfs_link(struct mount_ctx *mnt_ctx) +{ + int rc; + struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb; + struct smb3_fs_context *ctx = mnt_ctx->fs_ctx; + char *full_path; + int num_links = 0; + + full_path = build_unc_path_to_root(ctx, cifs_sb, true); + if (IS_ERR(full_path)) + return PTR_ERR(full_path); + + kfree(mnt_ctx->origin_fullpath); + mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls, + cifs_remap(cifs_sb)); + kfree(full_path); + + if (IS_ERR(mnt_ctx->origin_fullpath)) { + rc = PTR_ERR(mnt_ctx->origin_fullpath); + mnt_ctx->origin_fullpath = NULL; + return rc; + } + + do { + rc = __follow_dfs_link(mnt_ctx); + if (!rc || rc != -EREMOTE) + break; + } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS); + + return rc; +} + +/* Set up DFS referral paths for failover */ +static void setup_server_referral_paths(struct mount_ctx *mnt_ctx) +{ + struct TCP_Server_Info *server = mnt_ctx->server; + + mutex_lock(&server->refpath_lock); + server->origin_fullpath = mnt_ctx->origin_fullpath; + server->leaf_fullpath = mnt_ctx->leaf_fullpath; + server->current_fullpath = mnt_ctx->leaf_fullpath; + mutex_unlock(&server->refpath_lock); + mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL; +} + +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) +{ + int rc; + struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, }; + struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl); + bool isdfs; + + rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl); + if (rc) + goto error; + if (!isdfs) + goto out; + + /* proceed as DFS mount */ + uuid_gen(&mnt_ctx.mount_id); + rc = connect_dfs_root(&mnt_ctx, &tl); + dfs_cache_free_tgts(&tl); + + if (rc) + goto error; + + rc = is_path_remote(&mnt_ctx); + if (rc) + rc = follow_dfs_link(&mnt_ctx); + if (rc) + goto error; + + setup_server_referral_paths(&mnt_ctx); + /* + * After reconnecting to a different server, unique ids won't match anymore, so we disable + * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE). + */ + cifs_autodisable_serverino(cifs_sb); + /* + * Force the use of prefix path to support failover on DFS paths that resolve to targets + * that have different prefix paths. + */ + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; + kfree(cifs_sb->prepath); + cifs_sb->prepath = ctx->prepath; + ctx->prepath = NULL; + uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id); + +out: + cifs_try_adding_channels(cifs_sb, mnt_ctx.ses); + rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon); + if (rc) + goto error; + + free_xid(mnt_ctx.xid); + return rc; + +error: + dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id); + kfree(mnt_ctx.origin_fullpath); + kfree(mnt_ctx.leaf_fullpath); + mount_put_conns(&mnt_ctx); + return rc; +} +#else +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) +{ + int rc = 0; + struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, }; + + rc = mount_get_conns(&mnt_ctx); + if (rc) + goto error; + + if (mnt_ctx.tcon) { + rc = is_path_remote(&mnt_ctx); + if (rc == -EREMOTE) + rc = -EOPNOTSUPP; + if (rc) + goto error; + } + + rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon); + if (rc) + goto error; + + free_xid(mnt_ctx.xid); + return rc; + +error: + mount_put_conns(&mnt_ctx); + return rc; +} +#endif + +/* + * Issue a TREE_CONNECT request. + */ +int +CIFSTCon(const unsigned int xid, struct cifs_ses *ses, + const char *tree, struct cifs_tcon *tcon, + const struct nls_table *nls_codepage) +{ + struct smb_hdr *smb_buffer; + struct smb_hdr *smb_buffer_response; + TCONX_REQ *pSMB; + TCONX_RSP *pSMBr; + unsigned char *bcc_ptr; + int rc = 0; + int length; + __u16 bytes_left, count; + + if (ses == NULL) + return -EIO; + + smb_buffer = cifs_buf_get(); + if (smb_buffer == NULL) + return -ENOMEM; + + smb_buffer_response = smb_buffer; + + header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX, + NULL /*no tid */ , 4 /*wct */ ); + + smb_buffer->Mid = get_next_mid(ses->server); + smb_buffer->Uid = ses->Suid; + pSMB = (TCONX_REQ *) smb_buffer; + pSMBr = (TCONX_RSP *) smb_buffer_response; + + pSMB->AndXCommand = 0xFF; + pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO); + bcc_ptr = &pSMB->Password[0]; + + pSMB->PasswordLength = cpu_to_le16(1); /* minimum */ + *bcc_ptr = 0; /* password is null byte */ + bcc_ptr++; /* skip password */ + /* already aligned so no need to do it below */ + + if (ses->server->sign) + smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; + + if (ses->capabilities & CAP_STATUS32) { + smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS; + } + if (ses->capabilities & CAP_DFS) { + smb_buffer->Flags2 |= SMBFLG2_DFS; + } + if (ses->capabilities & CAP_UNICODE) { + smb_buffer->Flags2 |= SMBFLG2_UNICODE; + length = + cifs_strtoUTF16((__le16 *) bcc_ptr, tree, + 6 /* max utf8 char length in bytes */ * + (/* server len*/ + 256 /* share len */), nls_codepage); + bcc_ptr += 2 * length; /* convert num 16 bit words to bytes */ + bcc_ptr += 2; /* skip trailing null */ + } else { /* ASCII */ + strcpy(bcc_ptr, tree); + bcc_ptr += strlen(tree) + 1; + } + strcpy(bcc_ptr, "?????"); + bcc_ptr += strlen("?????"); + bcc_ptr += 1; + count = bcc_ptr - &pSMB->Password[0]; + be32_add_cpu(&pSMB->hdr.smb_buf_length, count); + pSMB->ByteCount = cpu_to_le16(count); + + rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length, + 0); + + /* above now done in SendReceive */ + if (rc == 0) { + bool is_unicode; + + tcon->tid = smb_buffer_response->Tid; + bcc_ptr = pByteArea(smb_buffer_response); + bytes_left = get_bcc(smb_buffer_response); + length = strnlen(bcc_ptr, bytes_left - 2); + if (smb_buffer->Flags2 & SMBFLG2_UNICODE) + is_unicode = true; + else + is_unicode = false; + + + /* skip service field (NB: this field is always ASCII) */ + if (length == 3) { + if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') && + (bcc_ptr[2] == 'C')) { + cifs_dbg(FYI, "IPC connection\n"); + tcon->ipc = true; + tcon->pipe = true; + } + } else if (length == 2) { + if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) { + /* the most common case */ + cifs_dbg(FYI, "disk share connection\n"); + } + } + bcc_ptr += length + 1; + bytes_left -= (length + 1); + strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name)); + + /* mostly informational -- no need to fail on error here */ + kfree(tcon->nativeFileSystem); + tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr, + bytes_left, is_unicode, + nls_codepage); + + cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem); + + if ((smb_buffer_response->WordCount == 3) || + (smb_buffer_response->WordCount == 7)) + /* field is in same location */ + tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport); + else + tcon->Flags = 0; + cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags); + } + + cifs_buf_release(smb_buffer); + return rc; +} + +static void delayed_free(struct rcu_head *p) +{ + struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu); + + unload_nls(cifs_sb->local_nls); + smb3_cleanup_fs_context(cifs_sb->ctx); + kfree(cifs_sb); +} + +void +cifs_umount(struct cifs_sb_info *cifs_sb) +{ + struct rb_root *root = &cifs_sb->tlink_tree; + struct rb_node *node; + struct tcon_link *tlink; + + cancel_delayed_work_sync(&cifs_sb->prune_tlinks); + + spin_lock(&cifs_sb->tlink_tree_lock); + while ((node = rb_first(root))) { + tlink = rb_entry(node, struct tcon_link, tl_rbnode); + cifs_get_tlink(tlink); + clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); + rb_erase(node, root); + + spin_unlock(&cifs_sb->tlink_tree_lock); + cifs_put_tlink(tlink); + spin_lock(&cifs_sb->tlink_tree_lock); + } + spin_unlock(&cifs_sb->tlink_tree_lock); + + kfree(cifs_sb->prepath); +#ifdef CONFIG_CIFS_DFS_UPCALL + dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id); +#endif + call_rcu(&cifs_sb->rcu, delayed_free); +} + +int +cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses, + struct TCP_Server_Info *server) +{ + int rc = 0; + + if (!server->ops->need_neg || !server->ops->negotiate) + return -ENOSYS; + + /* only send once per connect */ + spin_lock(&server->srv_lock); + if (server->tcpStatus != CifsGood && + server->tcpStatus != CifsNew && + server->tcpStatus != CifsNeedNegotiate) { + spin_unlock(&server->srv_lock); + return -EHOSTDOWN; + } + + if (!server->ops->need_neg(server) && + server->tcpStatus == CifsGood) { + 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 TCP_Server_Info *pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server; + struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr; + struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr; + bool is_binding = false; + + spin_lock(&ses->ses_lock); + cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n", + __func__, ses->chans_need_reconnect); + + if (ses->ses_status != SES_GOOD && + ses->ses_status != SES_NEW && + ses->ses_status != SES_NEED_RECON) { + spin_unlock(&ses->ses_lock); + return -EHOSTDOWN; + } + + /* only send once per connect */ + spin_lock(&ses->chan_lock); + if (CIFS_ALL_CHANS_GOOD(ses)) { + if (ses->ses_status == SES_NEED_RECON) + ses->ses_status = SES_GOOD; + spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); + return 0; + } + + cifs_chan_set_in_reconnect(ses, server); + is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses); + spin_unlock(&ses->chan_lock); + + if (!is_binding) { + ses->ses_status = SES_IN_SETUP; + + /* force iface_list refresh */ + ses->iface_last_update = 0; + } + spin_unlock(&ses->ses_lock); + + /* update ses ip_addr only for primary chan */ + if (server == pserver) { + 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 (!is_binding) { + ses->capabilities = server->capabilities; + if (!linuxExtEnabled) + ses->capabilities &= (~server->vals->cap_unix); + + if (ses->auth_key.response) { + cifs_dbg(FYI, "Free previous auth_key.response = %p\n", + ses->auth_key.response); + kfree_sensitive(ses->auth_key.response); + ses->auth_key.response = NULL; + ses->auth_key.len = 0; + } + } + + cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n", + server->sec_mode, server->capabilities, server->timeAdj); + + if (server->ops->sess_setup) + rc = server->ops->sess_setup(xid, ses, server, nls_info); + + if (rc) { + cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc); + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_IN_SETUP) + ses->ses_status = SES_NEED_RECON; + spin_lock(&ses->chan_lock); + cifs_chan_clear_in_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); + } else { + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_IN_SETUP) + ses->ses_status = SES_GOOD; + spin_lock(&ses->chan_lock); + cifs_chan_clear_in_reconnect(ses, server); + cifs_chan_clear_need_reconnect(ses, server); + spin_unlock(&ses->chan_lock); + spin_unlock(&ses->ses_lock); + } + + return rc; +} + +static int +cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses) +{ + ctx->sectype = ses->sectype; + + /* krb5 is special, since we don't need username or pw */ + if (ctx->sectype == Kerberos) + return 0; + + return cifs_set_cifscreds(ctx, ses); +} + +static struct cifs_tcon * +cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid) +{ + int rc; + struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb); + struct cifs_ses *ses; + struct cifs_tcon *tcon = NULL; + struct smb3_fs_context *ctx; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (ctx == NULL) + return ERR_PTR(-ENOMEM); + + ctx->local_nls = cifs_sb->local_nls; + ctx->linux_uid = fsuid; + ctx->cred_uid = fsuid; + ctx->UNC = master_tcon->tree_name; + ctx->retry = master_tcon->retry; + ctx->nocase = master_tcon->nocase; + ctx->nohandlecache = master_tcon->nohandlecache; + ctx->local_lease = master_tcon->local_lease; + ctx->no_lease = master_tcon->no_lease; + ctx->resilient = master_tcon->use_resilient; + ctx->persistent = master_tcon->use_persistent; + ctx->handle_timeout = master_tcon->handle_timeout; + ctx->no_linux_ext = !master_tcon->unix_ext; + ctx->linux_ext = master_tcon->posix_extensions; + ctx->sectype = master_tcon->ses->sectype; + ctx->sign = master_tcon->ses->sign; + ctx->seal = master_tcon->seal; + ctx->witness = master_tcon->use_witness; + + rc = cifs_set_vol_auth(ctx, master_tcon->ses); + if (rc) { + tcon = ERR_PTR(rc); + goto out; + } + + /* get a reference for the same TCP session */ + spin_lock(&cifs_tcp_ses_lock); + ++master_tcon->ses->server->srv_count; + spin_unlock(&cifs_tcp_ses_lock); + + ses = cifs_get_smb_ses(master_tcon->ses->server, ctx); + if (IS_ERR(ses)) { + tcon = (struct cifs_tcon *)ses; + cifs_put_tcp_session(master_tcon->ses->server, 0); + goto out; + } + + tcon = cifs_get_tcon(ses, ctx); + if (IS_ERR(tcon)) { + cifs_put_smb_ses(ses); + goto out; + } + +#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY + if (cap_unix(ses)) + reset_cifs_unix_caps(0, tcon, NULL, ctx); +#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */ + +out: + kfree(ctx->username); + kfree_sensitive(ctx->password); + kfree(ctx); + + return tcon; +} + +struct cifs_tcon * +cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb) +{ + return tlink_tcon(cifs_sb_master_tlink(cifs_sb)); +} + +/* find and return a tlink with given uid */ +static struct tcon_link * +tlink_rb_search(struct rb_root *root, kuid_t uid) +{ + struct rb_node *node = root->rb_node; + struct tcon_link *tlink; + + while (node) { + tlink = rb_entry(node, struct tcon_link, tl_rbnode); + + if (uid_gt(tlink->tl_uid, uid)) + node = node->rb_left; + else if (uid_lt(tlink->tl_uid, uid)) + node = node->rb_right; + else + return tlink; + } + return NULL; +} + +/* insert a tcon_link into the tree */ +static void +tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink) +{ + struct rb_node **new = &(root->rb_node), *parent = NULL; + struct tcon_link *tlink; + + while (*new) { + tlink = rb_entry(*new, struct tcon_link, tl_rbnode); + parent = *new; + + if (uid_gt(tlink->tl_uid, new_tlink->tl_uid)) + new = &((*new)->rb_left); + else + new = &((*new)->rb_right); + } + + rb_link_node(&new_tlink->tl_rbnode, parent, new); + rb_insert_color(&new_tlink->tl_rbnode, root); +} + +/* + * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the + * current task. + * + * If the superblock doesn't refer to a multiuser mount, then just return + * the master tcon for the mount. + * + * First, search the rbtree for an existing tcon for this fsuid. If one + * exists, then check to see if it's pending construction. If it is then wait + * for construction to complete. Once it's no longer pending, check to see if + * it failed and either return an error or retry construction, depending on + * the timeout. + * + * If one doesn't exist then insert a new tcon_link struct into the tree and + * try to construct a new one. + */ +struct tcon_link * +cifs_sb_tlink(struct cifs_sb_info *cifs_sb) +{ + int ret; + kuid_t fsuid = current_fsuid(); + struct tcon_link *tlink, *newtlink; + + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) + return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb)); + + spin_lock(&cifs_sb->tlink_tree_lock); + tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid); + if (tlink) + cifs_get_tlink(tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + + if (tlink == NULL) { + newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL); + if (newtlink == NULL) + return ERR_PTR(-ENOMEM); + newtlink->tl_uid = fsuid; + newtlink->tl_tcon = ERR_PTR(-EACCES); + set_bit(TCON_LINK_PENDING, &newtlink->tl_flags); + set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags); + cifs_get_tlink(newtlink); + + spin_lock(&cifs_sb->tlink_tree_lock); + /* was one inserted after previous search? */ + tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid); + if (tlink) { + cifs_get_tlink(tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + kfree(newtlink); + goto wait_for_construction; + } + tlink = newtlink; + tlink_rb_insert(&cifs_sb->tlink_tree, tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + } else { +wait_for_construction: + ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING, + TASK_INTERRUPTIBLE); + if (ret) { + cifs_put_tlink(tlink); + return ERR_PTR(-ERESTARTSYS); + } + + /* if it's good, return it */ + if (!IS_ERR(tlink->tl_tcon)) + return tlink; + + /* return error if we tried this already recently */ + if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) { + cifs_put_tlink(tlink); + return ERR_PTR(-EACCES); + } + + if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags)) + goto wait_for_construction; + } + + tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid); + clear_bit(TCON_LINK_PENDING, &tlink->tl_flags); + wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING); + + if (IS_ERR(tlink->tl_tcon)) { + cifs_put_tlink(tlink); + return ERR_PTR(-EACCES); + } + + return tlink; +} + +/* + * periodic workqueue job that scans tcon_tree for a superblock and closes + * out tcons. + */ +static void +cifs_prune_tlinks(struct work_struct *work) +{ + struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info, + prune_tlinks.work); + struct rb_root *root = &cifs_sb->tlink_tree; + struct rb_node *node; + struct rb_node *tmp; + struct tcon_link *tlink; + + /* + * Because we drop the spinlock in the loop in order to put the tlink + * it's not guarded against removal of links from the tree. The only + * places that remove entries from the tree are this function and + * umounts. Because this function is non-reentrant and is canceled + * before umount can proceed, this is safe. + */ + spin_lock(&cifs_sb->tlink_tree_lock); + node = rb_first(root); + while (node != NULL) { + tmp = node; + node = rb_next(tmp); + tlink = rb_entry(tmp, struct tcon_link, tl_rbnode); + + if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) || + atomic_read(&tlink->tl_count) != 0 || + time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies)) + continue; + + cifs_get_tlink(tlink); + clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); + rb_erase(tmp, root); + + spin_unlock(&cifs_sb->tlink_tree_lock); + cifs_put_tlink(tlink); + spin_lock(&cifs_sb->tlink_tree_lock); + } + spin_unlock(&cifs_sb->tlink_tree_lock); + + queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks, + TLINK_IDLE_EXPIRE); +} + +#ifdef CONFIG_CIFS_DFS_UPCALL +/* Update dfs referral path of superblock */ +static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb, + const char *target) +{ + int rc = 0; + size_t len = strlen(target); + char *refpath, *npath; + + if (unlikely(len < 2 || *target != '\\')) + return -EINVAL; + + if (target[1] == '\\') { + len += 1; + refpath = kmalloc(len, GFP_KERNEL); + if (!refpath) + return -ENOMEM; + + scnprintf(refpath, len, "%s", target); + } else { + len += sizeof("\\"); + refpath = kmalloc(len, GFP_KERNEL); + if (!refpath) + return -ENOMEM; + + scnprintf(refpath, len, "\\%s", target); + } + + npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb)); + kfree(refpath); + + if (IS_ERR(npath)) { + rc = PTR_ERR(npath); + } else { + mutex_lock(&server->refpath_lock); + kfree(server->leaf_fullpath); + server->leaf_fullpath = npath; + mutex_unlock(&server->refpath_lock); + server->current_fullpath = server->leaf_fullpath; + } + return rc; +} + +static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host, + size_t tcp_host_len, char *share, bool *target_match) +{ + int rc = 0; + const char *dfs_host; + size_t dfs_host_len; + + *target_match = true; + extract_unc_hostname(share, &dfs_host, &dfs_host_len); + + /* Check if hostnames or addresses match */ + if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) { + cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len, + dfs_host, (int)tcp_host_len, tcp_host); + rc = match_target_ip(server, dfs_host, dfs_host_len, target_match); + if (rc) + cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc); + } + return rc; +} + +static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, char *tree, bool islink, + struct dfs_cache_tgt_list *tl) +{ + int rc; + struct TCP_Server_Info *server = tcon->ses->server; + const struct smb_version_operations *ops = server->ops; + struct cifs_tcon *ipc = tcon->ses->tcon_ipc; + char *share = NULL, *prefix = NULL; + const char *tcp_host; + size_t tcp_host_len; + struct dfs_cache_tgt_iterator *tit; + bool target_match; + + extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len); + + tit = dfs_cache_get_tgt_iterator(tl); + if (!tit) { + rc = -ENOENT; + goto out; + } + + /* Try to tree connect to all dfs targets */ + for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) { + const char *target = dfs_cache_get_tgt_name(tit); + struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl); + + kfree(share); + kfree(prefix); + share = prefix = NULL; + + /* Check if share matches with tcp ses */ + rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix); + if (rc) { + cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc); + break; + } + + rc = target_share_matches_server(server, tcp_host, tcp_host_len, share, + &target_match); + if (rc) + break; + if (!target_match) { + rc = -EHOSTUNREACH; + continue; + } + + if (ipc->need_reconnect) { + scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname); + rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls); + if (rc) + break; + } + + scnprintf(tree, MAX_TREE_SIZE, "\\%s", share); + if (!islink) { + rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls); + break; + } + /* + * If no dfs referrals were returned from link target, then just do a TREE_CONNECT + * to it. Otherwise, cache the dfs referral and then mark current tcp ses for + * reconnect so either the demultiplex thread or the echo worker will reconnect to + * newly resolved target. + */ + if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target, + NULL, &ntl)) { + rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls); + if (rc) + continue; + rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit); + if (!rc) + rc = cifs_update_super_prepath(cifs_sb, prefix); + } else { + /* Target is another dfs share */ + rc = update_server_fullpath(server, cifs_sb, target); + dfs_cache_free_tgts(tl); + + if (!rc) { + rc = -EREMOTE; + list_replace_init(&ntl.tl_list, &tl->tl_list); + } else + dfs_cache_free_tgts(&ntl); + } + break; + } + +out: + kfree(share); + kfree(prefix); + + return rc; +} + +static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon, + struct cifs_sb_info *cifs_sb, char *tree, bool islink, + struct dfs_cache_tgt_list *tl) +{ + int rc; + int num_links = 0; + struct TCP_Server_Info *server = tcon->ses->server; + + do { + rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl); + if (!rc || rc != -EREMOTE) + break; + } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS); + /* + * If we couldn't tree connect to any targets from last referral path, then retry from + * original referral path. + */ + if (rc && server->current_fullpath != server->origin_fullpath) { + server->current_fullpath = server->origin_fullpath; + cifs_signal_cifsd_for_reconnect(server, true); + } + + dfs_cache_free_tgts(tl); + return rc; +} + +int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc) +{ + int rc; + struct TCP_Server_Info *server = tcon->ses->server; + const struct smb_version_operations *ops = server->ops; + struct super_block *sb = NULL; + struct cifs_sb_info *cifs_sb; + struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl); + char *tree; + struct dfs_info3_param ref = {0}; + + /* only send once per connect */ + spin_lock(&tcon->tc_lock); + if (tcon->ses->ses_status != SES_GOOD || + (tcon->status != TID_NEW && + tcon->status != TID_NEED_TCON)) { + spin_unlock(&tcon->tc_lock); + return 0; + } + tcon->status = TID_IN_TCON; + spin_unlock(&tcon->tc_lock); + + tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL); + if (!tree) { + rc = -ENOMEM; + goto out; + } + + if (tcon->ipc) { + scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname); + rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); + goto out; + } + + sb = cifs_get_tcp_super(server); + if (IS_ERR(sb)) { + rc = PTR_ERR(sb); + cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc); + goto out; + } + + cifs_sb = CIFS_SB(sb); + + /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */ + if (!server->current_fullpath || + dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) { + rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls); + goto out; + } + + rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK, + &tl); + free_dfs_info_param(&ref); + +out: + kfree(tree); + cifs_put_tcp_super(sb); + + if (rc) { + spin_lock(&tcon->tc_lock); + if (tcon->status == TID_IN_TCON) + tcon->status = TID_NEED_TCON; + spin_unlock(&tcon->tc_lock); + } else { + spin_lock(&tcon->tc_lock); + if (tcon->status == TID_IN_TCON) + tcon->status = TID_GOOD; + spin_unlock(&tcon->tc_lock); + tcon->need_reconnect = false; + } + + return rc; +} +#else +int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc) +{ + int rc; + const struct smb_version_operations *ops = tcon->ses->server->ops; + + /* only send once per connect */ + spin_lock(&tcon->tc_lock); + if (tcon->ses->ses_status != SES_GOOD || + (tcon->status != TID_NEW && + tcon->status != TID_NEED_TCON)) { + spin_unlock(&tcon->tc_lock); + return 0; + } + tcon->status = TID_IN_TCON; + spin_unlock(&tcon->tc_lock); + + rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc); + if (rc) { + spin_lock(&tcon->tc_lock); + if (tcon->status == TID_IN_TCON) + tcon->status = TID_NEED_TCON; + spin_unlock(&tcon->tc_lock); + } else { + spin_lock(&tcon->tc_lock); + if (tcon->status == TID_IN_TCON) + tcon->status = TID_GOOD; + tcon->need_reconnect = false; + spin_unlock(&tcon->tc_lock); + } + + return rc; +} +#endif |