// SPDX-License-Identifier: LGPL-2.1 /* * * Copyright (C) International Business Machines Corp., 2002,2011 * Author(s): Steve French (sfrench@us.ibm.com) * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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; 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(&cifs_tcp_ses_lock); rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr, strlen(ipaddr)); spin_unlock(&cifs_tcp_ses_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 cifs_resolve_server(struct work_struct *work) { int rc; struct TCP_Server_Info *server = container_of(work, struct TCP_Server_Info, resolve.work); mutex_lock(&server->srv_mutex); /* * 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); } mutex_unlock(&server->srv_mutex); } /** * Mark all sessions and tcons for reconnect. * * @server needs to be previously set to CifsNeedReconnect. */ static void cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server) { struct list_head *tmp, *tmp2; struct cifs_ses *ses; struct cifs_tcon *tcon; struct mid_q_entry *mid_entry; struct list_head retry_list; server->maxBuf = 0; server->max_read = 0; cifs_dbg(FYI, "Mark tcp session as need reconnect\n"); trace_smb3_reconnect(server->CurrentMid, server->conn_id, server->hostname); /* * 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 sessions and tcons for reconnect\n", __func__); spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &server->smb_ses_list) { ses = list_entry(tmp, struct cifs_ses, smb_ses_list); ses->need_reconnect = true; list_for_each(tmp2, &ses->tcon_list) { tcon = list_entry(tmp2, struct cifs_tcon, tcon_list); tcon->need_reconnect = true; } if (ses->tcon_ipc) ses->tcon_ipc->need_reconnect = true; } spin_unlock(&cifs_tcp_ses_lock); /* do not want to be sending data on a socket we are freeing */ cifs_dbg(FYI, "%s: tearing down socket\n", __func__); mutex_lock(&server->srv_mutex); if (server->ssocket) { cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state, server->ssocket->flags); kernel_sock_shutdown(server->ssocket, SHUT_WR); cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state, server->ssocket->flags); sock_release(server->ssocket); server->ssocket = NULL; } server->sequence_number = 0; server->session_estab = false; kfree(server->session_key.response); server->session_key.response = NULL; server->session_key.len = 0; server->lstrp = jiffies; /* mark submitted MIDs for retry and issue callback */ INIT_LIST_HEAD(&retry_list); cifs_dbg(FYI, "%s: moving mids to private list\n", __func__); spin_lock(&GlobalMid_Lock); list_for_each_safe(tmp, tmp2, &server->pending_mid_q) { mid_entry = list_entry(tmp, struct mid_q_entry, qhead); kref_get(&mid_entry->refcount); if (mid_entry->mid_state == MID_REQUEST_SUBMITTED) mid_entry->mid_state = MID_RETRY_NEEDED; list_move(&mid_entry->qhead, &retry_list); mid_entry->mid_flags |= MID_DELETED; } spin_unlock(&GlobalMid_Lock); mutex_unlock(&server->srv_mutex); cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__); list_for_each_safe(tmp, tmp2, &retry_list) { mid_entry = list_entry(tmp, struct mid_q_entry, qhead); list_del_init(&mid_entry->qhead); mid_entry->callback(mid_entry); cifs_mid_q_entry_release(mid_entry); } if (cifs_rdma_enabled(server)) { mutex_lock(&server->srv_mutex); smbd_destroy(server); mutex_unlock(&server->srv_mutex); } } static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets) { spin_lock(&GlobalMid_Lock); server->nr_targets = num_targets; if (server->tcpStatus == CifsExiting) { /* the demux thread will exit normally next time through the loop */ spin_unlock(&GlobalMid_Lock); wake_up(&server->response_q); return false; } server->tcpStatus = CifsNeedReconnect; spin_unlock(&GlobalMid_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) */ static int __cifs_reconnect(struct TCP_Server_Info *server) { int rc = 0; if (!cifs_tcp_ses_needs_reconnect(server, 1)) return 0; cifs_mark_tcp_ses_conns_for_reconnect(server); do { try_to_freeze(); mutex_lock(&server->srv_mutex); 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) { mutex_unlock(&server->srv_mutex); cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc); msleep(3000); } else { atomic_inc(&tcpSesReconnectCount); set_credits(server, 1); spin_lock(&GlobalMid_Lock); if (server->tcpStatus != CifsExiting) server->tcpStatus = CifsNeedNegotiate; spin_unlock(&GlobalMid_Lock); cifs_swn_reset_server_dstaddr(server); mutex_unlock(&server->srv_mutex); } } while (server->tcpStatus == CifsNeedReconnect); if (server->tcpStatus == CifsNeedNegotiate) mod_delayed_work(cifsiod_wq, &server->echo, 0); wake_up(&server->response_q); return rc; } #ifdef CONFIG_CIFS_DFS_UPCALL static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target) { int rc; char *hostname; if (!cifs_swn_set_server_dstaddr(server)) { if (server->hostname != target) { hostname = extract_hostname(target); if (!IS_ERR(hostname)) { kfree(server->hostname); server->hostname = hostname; } else { cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n", __func__, PTR_ERR(hostname)); cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__, server->hostname); } } /* resolve the hostname again to make sure that IP address is up-to-date. */ rc = reconn_set_ipaddr_from_hostname(server); cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc); } /* Reconnect the socket */ if (cifs_rdma_enabled(server)) rc = smbd_reconnect(server); else rc = generic_ip_connect(server); return rc; } static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl, struct dfs_cache_tgt_iterator **target_hint) { int rc; struct dfs_cache_tgt_iterator *tit; *target_hint = NULL; /* If dfs target list is empty, then reconnect to last server */ tit = dfs_cache_get_tgt_iterator(tl); if (!tit) return __reconnect_target_unlocked(server, server->hostname); /* Otherwise, try every dfs target in @tl */ for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) { rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit)); if (!rc) { *target_hint = tit; break; } } return rc; } static int reconnect_dfs_server(struct TCP_Server_Info *server) { int rc = 0; const char *refpath = server->current_fullpath + 1; struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl); struct dfs_cache_tgt_iterator *target_hint = NULL; int num_targets = 0; /* * Determine the number of dfs targets the referral path in @cifs_sb resolves to. * * smb2_reconnect() needs to know how long it should wait based upon the number of dfs * targets (server->nr_targets). It's also possible that the cached referral was cleared * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after * refreshing the referral, so, in this case, default it to 1. */ if (!dfs_cache_noreq_find(refpath, NULL, &tl)) num_targets = dfs_cache_get_nr_tgts(&tl); if (!num_targets) num_targets = 1; if (!cifs_tcp_ses_needs_reconnect(server, num_targets)) return 0; cifs_mark_tcp_ses_conns_for_reconnect(server); do { try_to_freeze(); mutex_lock(&server->srv_mutex); rc = reconnect_target_unlocked(server, &tl, &target_hint); if (rc) { /* Failed to reconnect socket */ mutex_unlock(&server->srv_mutex); 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(&GlobalMid_Lock); if (server->tcpStatus != CifsExiting) server->tcpStatus = CifsNeedNegotiate; spin_unlock(&GlobalMid_Lock); cifs_swn_reset_server_dstaddr(server); mutex_unlock(&server->srv_mutex); } 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 */ if (server->tcpStatus == CifsNeedNegotiate) mod_delayed_work(cifsiod_wq, &server->echo, 0); wake_up(&server->response_q); return rc; } int cifs_reconnect(struct TCP_Server_Info *server) { /* If tcp session is not an dfs connection, then reconnect to last target server */ spin_lock(&cifs_tcp_ses_lock); if (!server->is_dfs_conn || !server->origin_fullpath || !server->leaf_fullpath) { spin_unlock(&cifs_tcp_ses_lock); return __cifs_reconnect(server); } spin_unlock(&cifs_tcp_ses_lock); return reconnect_dfs_server(server); } #else int cifs_reconnect(struct TCP_Server_Info *server) { return __cifs_reconnect(server); } #endif static void cifs_echo_request(struct work_struct *work) { int rc; struct TCP_Server_Info *server = container_of(work, struct TCP_Server_Info, echo.work); /* * We cannot send an echo if it is disabled. * Also, no need to ping if we got a response recently. */ if (server->tcpStatus == CifsNeedReconnect || server->tcpStatus == CifsExiting || server->tcpStatus == CifsNew || (server->ops->can_echo && !server->ops->can_echo(server)) || time_before(jiffies, server->lstrp + server->echo_interval - HZ)) goto requeue_echo; rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS; if (rc) cifs_dbg(FYI, "Unable to send echo request to server: %s\n", server->hostname); /* Check witness registrations */ cifs_swn_check(); requeue_echo: queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval); } static bool allocate_buffers(struct TCP_Server_Info *server) { if (!server->bigbuf) { server->bigbuf = (char *)cifs_buf_get(); if (!server->bigbuf) { cifs_server_dbg(VFS, "No memory for large SMB response\n"); msleep(3000); /* retry will check if exiting */ return false; } } else if (server->large_buf) { /* we are reusing a dirty large buf, clear its start */ memset(server->bigbuf, 0, HEADER_SIZE(server)); } if (!server->smallbuf) { server->smallbuf = (char *)cifs_small_buf_get(); if (!server->smallbuf) { cifs_server_dbg(VFS, "No memory for SMB response\n"); msleep(1000); /* retry will check if exiting */ return false; } /* beginning of smb buffer is cleared in our buf_get */ } else { /* if existing small buf clear beginning */ memset(server->smallbuf, 0, HEADER_SIZE(server)); } return true; } static bool server_unresponsive(struct TCP_Server_Info *server) { /* * We need to wait 3 echo intervals to make sure we handle such * situations right: * 1s client sends a normal SMB request * 2s client gets a response * 30s echo workqueue job pops, and decides we got a response recently * and don't need to send another * ... * 65s kernel_recvmsg times out, and we see that we haven't gotten * a response in >60s. */ 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)) { cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n", (3 * server->echo_interval) / HZ); cifs_reconnect(server); return true; } 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); 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); if (server->tcpStatus == CifsExiting) return -ESHUTDOWN; if (server->tcpStatus == CifsNeedReconnect) { cifs_reconnect(server); return -ECONNABORTED; } 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); return -ECONNABORTED; } } return total_read; } int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf, unsigned int to_read) { struct msghdr smb_msg = {}; struct kvec iov = {.iov_base = buf, .iov_len = to_read}; iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read); return cifs_readv_from_socket(server, &smb_msg); } ssize_t cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read) { struct msghdr smb_msg = {}; /* * iov_iter_discard already sets smb_msg.type and count and iov_offset * and cifs_readv_from_socket sets msg_control and msg_controllen * so little to initialize in struct msghdr */ iov_iter_discard(&smb_msg.msg_iter, READ, to_read); return cifs_readv_from_socket(server, &smb_msg); } int cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page, unsigned int page_offset, unsigned int to_read) { struct msghdr smb_msg = {}; struct bio_vec bv = { .bv_page = page, .bv_len = to_read, .bv_offset = page_offset}; iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read); return cifs_readv_from_socket(server, &smb_msg); } static bool is_smb_response(struct TCP_Server_Info *server, unsigned char type) { /* * The first byte big endian of the length field, * is actually not part of the length but the type * with the most common, zero, as regular data. */ switch (type) { case RFC1002_SESSION_MESSAGE: /* Regular SMB response */ return true; case RFC1002_SESSION_KEEP_ALIVE: cifs_dbg(FYI, "RFC 1002 session keep alive\n"); break; case RFC1002_POSITIVE_SESSION_RESPONSE: cifs_dbg(FYI, "RFC 1002 positive session response\n"); break; case RFC1002_NEGATIVE_SESSION_RESPONSE: /* * We get this from Windows 98 instead of an error on * SMB negprot response. */ cifs_dbg(FYI, "RFC 1002 negative session response\n"); /* give server a second to clean up */ msleep(1000); /* * Always try 445 first on reconnect since we get NACK * on some if we ever connected to port 139 (the NACK * is since we do not begin with RFC1001 session * initialize frame). */ cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT); cifs_reconnect(server); break; default: cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type); cifs_reconnect(server); } return false; } void dequeue_mid(struct mid_q_entry *mid, bool malformed) { #ifdef CONFIG_CIFS_STATS2 mid->when_received = jiffies; #endif spin_lock(&GlobalMid_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) pr_warn_once("trying to dequeue a deleted mid\n"); else { list_del_init(&mid->qhead); mid->mid_flags |= MID_DELETED; } spin_unlock(&GlobalMid_Lock); } static unsigned int smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server) { struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer; /* * SMB1 does not use credits. */ if (server->vals->header_preamble_size) 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); } static void clean_demultiplex_info(struct TCP_Server_Info *server) { int length; /* take it off the list, if it's not already */ spin_lock(&cifs_tcp_ses_lock); list_del_init(&server->tcp_ses_list); spin_unlock(&cifs_tcp_ses_lock); cancel_delayed_work_sync(&server->echo); cancel_delayed_work_sync(&server->resolve); spin_lock(&GlobalMid_Lock); server->tcpStatus = CifsExiting; spin_unlock(&GlobalMid_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(&GlobalMid_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(&GlobalMid_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); cifs_mid_q_entry_release(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) - server->vals->header_preamble_size) { cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length); cifs_reconnect(server); 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 - HEADER_SIZE(server) + 1 + server->vals->header_preamble_size); 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 length; /* * 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. We borrow the length * var for the rest of the loop to avoid a new stack var. * * 48 bytes is enough to display the header and a little bit * into the payload for debugging purposes. */ length = server->ops->check_message(buf, server->total_read, server); if (length != 0) 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); return -1; } if (server->ops->is_status_pending && server->ops->is_status_pending(buf, server)) return -1; if (!mid) return length; handle_mid(mid, server, buf, length); return 0; } static void smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server) { struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer; int scredits, in_flight; /* * SMB1 does not use credits. */ if (server->vals->header_preamble_size) 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_add_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 (server->vals->header_preamble_size == 0) server->total_read = 0; else server->total_read = length; /* * 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 < HEADER_SIZE(server) - 1 - server->vals->header_preamble_size) { cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n", server->pdu_size); cifs_reconnect(server); continue; } /* read down to the MID */ length = cifs_read_from_socket(server, buf + server->vals->header_preamble_size, HEADER_SIZE(server) - 1 - server->vals->header_preamble_size); if (length < 0) continue; server->total_read += length; if (server->ops->next_header) { next_offset = server->ops->next_header(buf); if (next_offset) server->pdu_size = next_offset; } memset(mids, 0, sizeof(mids)); memset(bufs, 0, sizeof(bufs)); num_mids = 0; if (server->ops->is_transform_hdr && server->ops->receive_transform && server->ops->is_transform_hdr(buf)) { length = server->ops->receive_transform(server, mids, bufs, &num_mids); } else { mids[0] = server->ops->find_mid(server, buf); bufs[0] = buf; num_mids = 1; if (!mids[0] || !mids[0]->receive) length = standard_receive3(server, mids[0]); else length = mids[0]->receive(server, mids[0]); } if (length < 0) { for (i = 0; i < num_mids; i++) if (mids[i]) cifs_mid_q_entry_release(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]); cifs_mid_q_entry_release(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(&midCount)); 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); } /* 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_exit(0); } /* * Returns true if srcaddr isn't specified and rhs isn't specified, or * if srcaddr is specified and matches the IP address of the rhs argument */ bool cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs) { switch (srcaddr->sa_family) { case AF_UNSPEC: return (rhs->sa_family == AF_UNSPEC); case AF_INET: { struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr; struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs; return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr); } case AF_INET6: { struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr; struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs; return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr); } default: WARN_ON(1); return false; /* don't expect to be here */ } } /* * If no port is specified in addr structure, we try to match with 445 port * and if it fails - with 139 ports. It should be called only if address * families of server and addr are equal. */ static bool match_port(struct TCP_Server_Info *server, struct sockaddr *addr) { __be16 port, *sport; /* SMBDirect manages its own ports, don't match it here */ if (server->rdma) return true; switch (addr->sa_family) { case AF_INET: sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port; port = ((struct sockaddr_in *) addr)->sin_port; break; case AF_INET6: sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port; port = ((struct sockaddr_in6 *) addr)->sin6_port; break; default: WARN_ON(1); return false; } if (!port) { port = htons(CIFS_PORT); if (port == *sport) return true; port = htons(RFC1001_PORT); } return port == *sport; } static bool match_address(struct TCP_Server_Info *server, struct sockaddr *addr, struct sockaddr *srcaddr) { switch (addr->sa_family) { case AF_INET: { struct sockaddr_in *addr4 = (struct sockaddr_in *)addr; struct sockaddr_in *srv_addr4 = (struct sockaddr_in *)&server->dstaddr; if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr) return false; break; } case AF_INET6: { struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr; struct sockaddr_in6 *srv_addr6 = (struct sockaddr_in6 *)&server->dstaddr; if (!ipv6_addr_equal(&addr6->sin6_addr, &srv_addr6->sin6_addr)) return false; if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id) return false; break; } default: WARN_ON(1); return false; /* don't expect to be here */ } if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr)) return false; return true; } static bool match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { /* * The select_sectype function should either return the ctx->sectype * that was specified, or "Unspecified" if that sectype was not * compatible with the given NEGOTIATE request. */ if (server->ops->select_sectype(server, ctx->sectype) == Unspecified) return false; /* * Now check if signing mode is acceptable. No need to check * global_secflags at this point since if MUST_SIGN is set then * the server->sign had better be too. */ if (ctx->sign && !server->sign) return false; return true; } static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr; if (ctx->nosharesock) return 0; /* this server does not share socket */ if (server->nosharesock) return 0; /* If multidialect negotiation see if existing sessions match one */ if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) { if (server->vals->protocol_id < SMB30_PROT_ID) return 0; } else if (strcmp(ctx->vals->version_string, SMBDEFAULT_VERSION_STRING) == 0) { if (server->vals->protocol_id < SMB21_PROT_ID) return 0; } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops)) return 0; if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns)) return 0; if (strcasecmp(server->hostname, ctx->server_hostname)) return 0; if (!match_address(server, addr, (struct sockaddr *)&ctx->srcaddr)) return 0; if (!match_port(server, addr)) return 0; if (!match_security(server, ctx)) return 0; if (server->echo_interval != ctx->echo_interval * HZ) return 0; if (server->rdma != ctx->rdma) return 0; if (server->ignore_signature != ctx->ignore_signature) return 0; if (server->min_offload != ctx->min_offload) return 0; return 1; } struct TCP_Server_Info * cifs_find_tcp_session(struct smb3_fs_context *ctx) { struct TCP_Server_Info *server; spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { #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) continue; #endif /* * Skip ses channels since they're only handled in lower layers * (e.g. cifs_send_recv). */ if (server->is_channel || !match_server(server, ctx)) continue; ++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); 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(&GlobalMid_Lock); server->tcpStatus = CifsExiting; spin_unlock(&GlobalMid_Lock); cifs_crypto_secmech_release(server); cifs_fscache_release_client_cookie(server); kfree(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 *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; init_waitqueue_head(&tcp_ses->response_q); init_waitqueue_head(&tcp_ses->request_q); INIT_LIST_HEAD(&tcp_ses->pending_mid_q); mutex_init(&tcp_ses->srv_mutex); memcpy(tcp_ses->workstation_RFC1001_name, ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL); memcpy(tcp_ses->server_RFC1001_name, ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL); tcp_ses->session_estab = false; tcp_ses->sequence_number = 0; tcp_ses->reconnect_instance = 1; tcp_ses->lstrp = jiffies; tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression); spin_lock_init(&tcp_ses->req_lock); 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 */ tcp_ses->tcpStatus = CifsNeedNegotiate; 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); cifs_fscache_get_client_cookie(tcp_ses); /* 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) { kfree(tcp_ses->hostname); if (tcp_ses->ssocket) sock_release(tcp_ses->ssocket); kfree(tcp_ses); } return ERR_PTR(rc); } static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx) { if (ctx->sectype != Unspecified && ctx->sectype != ses->sectype) return 0; /* * If an existing session is limited to less channels than * requested, it should not be reused */ spin_lock(&ses->chan_lock); if (ses->chan_max < ctx->max_channels) { spin_unlock(&ses->chan_lock); return 0; } spin_unlock(&ses->chan_lock); switch (ses->sectype) { case Kerberos: if (!uid_eq(ctx->cred_uid, ses->cred_uid)) return 0; break; default: /* NULL username means anonymous session */ if (ses->user_name == NULL) { if (!ctx->nullauth) return 0; break; } /* anything else takes username/password */ if (strncmp(ses->user_name, ctx->username ? ctx->username : "", CIFS_MAX_USERNAME_LEN)) return 0; if ((ctx->username && strlen(ctx->username) != 0) && ses->password != NULL && strncmp(ses->password, ctx->password ? ctx->password : "", CIFS_MAX_PASSWORD_LEN)) return 0; } return 1; } /** * cifs_setup_ipc - helper to setup the IPC tcon for the session * @ses: smb session to issue the request on * @ctx: the superblock configuration context to use for building the * new tree connection for the IPC (interprocess communication RPC) * * A new IPC connection is made and stored in the session * tcon_ipc. The IPC tcon has the same lifetime as the session. */ static int cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx) { int rc = 0, xid; struct cifs_tcon *tcon; char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0}; bool seal = false; struct TCP_Server_Info *server = ses->server; /* * If the mount request that resulted in the creation of the * session requires encryption, force IPC to be encrypted too. */ if (ctx->seal) { if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION) seal = true; else { cifs_server_dbg(VFS, "IPC: server doesn't support encryption\n"); return -EOPNOTSUPP; } } tcon = tconInfoAlloc(); if (tcon == NULL) return -ENOMEM; scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname); xid = get_xid(); tcon->ses = ses; tcon->ipc = true; tcon->seal = seal; rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls); free_xid(xid); if (rc) { cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc); tconInfoFree(tcon); goto out; } cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid); ses->tcon_ipc = tcon; out: return rc; } /** * cifs_free_ipc - helper to release the session IPC tcon * @ses: smb session to unmount the IPC from * * Needs to be called everytime a session is destroyed. * * On session close, the IPC is closed and the server must release all tcons of the session. * No need to send a tree disconnect here. * * Besides, it will make the server to not close durable and resilient files on session close, as * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request. */ static int cifs_free_ipc(struct cifs_ses *ses) { struct cifs_tcon *tcon = ses->tcon_ipc; if (tcon == NULL) return 0; tconInfoFree(tcon); ses->tcon_ipc = NULL; return 0; } static struct cifs_ses * cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) { struct cifs_ses *ses; spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { if (ses->status == CifsExiting) continue; if (!match_session(ses, ctx)) continue; ++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; cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); spin_lock(&cifs_tcp_ses_lock); if (ses->status == CifsExiting) { spin_unlock(&cifs_tcp_ses_lock); return; } cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count); cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE"); 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); spin_lock(&GlobalMid_Lock); if (ses->status == CifsGood) ses->status = CifsExiting; spin_unlock(&GlobalMid_Lock); cifs_free_ipc(ses); if (ses->status == CifsExiting && 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); spin_lock(&ses->chan_lock); chan_count = ses->chan_count; spin_unlock(&ses->chan_lock); /* close any extra channels */ if (chan_count > 1) { int i; for (i = 1; i < chan_count; i++) { /* * note: for now, we're okay accessing ses->chans * without chan_lock. But when chans can go away, we'll * need to introduce ref counting to make sure that chan * is not freed from under us. */ cifs_put_tcp_session(ses->chans[i].server, 0); ses->chans[i].server = NULL; } } sesInfoFree(ses); cifs_put_tcp_session(server, 0); } #ifdef CONFIG_KEYS /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */ #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1) /* Populate username and pw fields from keyring if possible */ static int cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses) { int rc = 0; int is_domain = 0; const char *delim, *payload; char *desc; ssize_t len; struct key *key; struct TCP_Server_Info *server = ses->server; struct sockaddr_in *sa; struct sockaddr_in6 *sa6; const struct user_key_payload *upayload; desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL); if (!desc) return -ENOMEM; /* try to find an address key first */ switch (server->dstaddr.ss_family) { case AF_INET: sa = (struct sockaddr_in *)&server->dstaddr; sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr); break; case AF_INET6: sa6 = (struct sockaddr_in6 *)&server->dstaddr; sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr); break; default: cifs_dbg(FYI, "Bad ss_family (%hu)\n", server->dstaddr.ss_family); rc = -EINVAL; goto out_err; } cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc); key = request_key(&key_type_logon, desc, ""); if (IS_ERR(key)) { if (!ses->domainName) { cifs_dbg(FYI, "domainName is NULL\n"); rc = PTR_ERR(key); goto out_err; } /* didn't work, try to find a domain key */ sprintf(desc, "cifs:d:%s", ses->domainName); cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc); key = request_key(&key_type_logon, desc, ""); if (IS_ERR(key)) { rc = PTR_ERR(key); goto out_err; } is_domain = 1; } down_read(&key->sem); upayload = user_key_payload_locked(key); if (IS_ERR_OR_NULL(upayload)) { rc = upayload ? PTR_ERR(upayload) : -EINVAL; goto out_key_put; } /* find first : in payload */ payload = upayload->data; delim = strnchr(payload, upayload->datalen, ':'); cifs_dbg(FYI, "payload=%s\n", payload); if (!delim) { cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n", upayload->datalen); rc = -EINVAL; goto out_key_put; } len = delim - payload; if (len > CIFS_MAX_USERNAME_LEN || len <= 0) { cifs_dbg(FYI, "Bad value from username search (len=%zd)\n", len); rc = -EINVAL; goto out_key_put; } ctx->username = kstrndup(payload, len, GFP_KERNEL); if (!ctx->username) { cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n", len); rc = -ENOMEM; goto out_key_put; } cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username); len = key->datalen - (len + 1); if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) { cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len); rc = -EINVAL; kfree(ctx->username); ctx->username = NULL; goto out_key_put; } ++delim; ctx->password = kstrndup(delim, len, GFP_KERNEL); if (!ctx->password) { cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n", len); rc = -ENOMEM; kfree(ctx->username); ctx->username = NULL; goto out_key_put; } /* * If we have a domain key then we must set the domainName in the * for the request. */ if (is_domain && ses->domainName) { ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL); if (!ctx->domainname) { cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n", len); rc = -ENOMEM; kfree(ctx->username); ctx->username = NULL; kfree_sensitive(ctx->password); ctx->password = NULL; goto out_key_put; } } 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->status); mutex_lock(&ses->session_mutex); rc = cifs_negotiate_protocol(xid, ses); if (rc) { mutex_unlock(&ses->session_mutex); /* problem -- put our ses reference */ cifs_put_smb_ses(ses); free_xid(xid); return ERR_PTR(rc); } if (ses->need_reconnect) { cifs_dbg(FYI, "Session needs reconnect\n"); rc = cifs_setup_session(xid, ses, 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); /* 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; } 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; mutex_lock(&ses->session_mutex); /* 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; spin_unlock(&ses->chan_lock); rc = cifs_negotiate_protocol(xid, ses); if (!rc) rc = cifs_setup_session(xid, ses, ctx->local_nls); /* each channel uses a different signing key */ memcpy(ses->chans[0].signkey, ses->smb3signingkey, sizeof(ses->smb3signingkey)); mutex_unlock(&ses->session_mutex); if (rc) goto get_ses_fail; /* success, put it on the list and add it as first channel */ spin_lock(&cifs_tcp_ses_lock); list_add(&ses->smb_ses_list, &server->smb_ses_list); spin_unlock(&cifs_tcp_ses_lock); free_xid(xid); cifs_setup_ipc(ses, ctx); return ses; get_ses_fail: sesInfoFree(ses); free_xid(xid); return ERR_PTR(rc); } static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx) { if (tcon->tidStatus == CifsExiting) return 0; if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE)) return 0; if (tcon->seal != ctx->seal) return 0; if (tcon->snapshot_time != ctx->snapshot_time) return 0; if (tcon->handle_timeout != ctx->handle_timeout) return 0; if (tcon->no_lease != ctx->no_lease) return 0; if (tcon->nodelete != ctx->nodelete) return 0; return 1; } static struct cifs_tcon * cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx) { struct list_head *tmp; struct cifs_tcon *tcon; spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &ses->tcon_list) { tcon = list_entry(tmp, struct cifs_tcon, tcon_list); if (!match_tcon(tcon, ctx)) continue; ++tcon->tc_count; spin_unlock(&cifs_tcp_ses_lock); return tcon; } spin_unlock(&cifs_tcp_ses_lock); return NULL; } void cifs_put_tcon(struct cifs_tcon *tcon) { unsigned int xid; struct cifs_ses *ses; /* * IPC tcon share the lifetime of their session and are * destroyed in the session put function */ if (tcon == NULL || tcon->ipc) return; ses = tcon->ses; cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count); spin_lock(&cifs_tcp_ses_lock); if (--tcon->tc_count > 0) { spin_unlock(&cifs_tcp_ses_lock); return; } /* tc_count can never go negative */ WARN_ON(tcon->tc_count < 0); 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); } } list_del_init(&tcon->tcon_list); spin_unlock(&cifs_tcp_ses_lock); 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 { cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n"); rc = -EOPNOTSUPP; goto out_fail; } } /* * BB Do we need to wrap session_mutex around this TCon call and Unix * SetFS as we do on SessSetup and reconnect? */ 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; 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); spin_lock(&cifs_tcp_ses_lock); list_add(&tcon->tcon_list, &ses->tcon_list); spin_unlock(&cifs_tcp_ses_lock); cifs_fscache_get_super_cookie(tcon); 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 = (struct cifs_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; 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(&cifs_tcp_ses_lock); cifs_put_tlink(tlink); return rc; } #ifdef CONFIG_DEBUG_LOCK_ALLOC static struct lock_class_key cifs_key[2]; static struct lock_class_key cifs_slock_key[2]; static inline void cifs_reclassify_socket4(struct socket *sock) { struct sock *sk = sock->sk; BUG_ON(!sock_allow_reclassification(sk)); sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS", &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]); } static inline void cifs_reclassify_socket6(struct socket *sock) { struct sock *sk = sock->sk; BUG_ON(!sock_allow_reclassification(sk)); sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS", &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]); } #else static inline void cifs_reclassify_socket4(struct socket *sock) { } static inline void cifs_reclassify_socket6(struct socket *sock) { } #endif /* See RFC1001 section 14 on representation of Netbios names */ static void rfc1002mangle(char *target, char *source, unsigned int length) { unsigned int i, j; for (i = 0, j = 0; i < (length); i++) { /* mask a nibble at a time and encode */ target[j] = 'A' + (0x0F & (source[i] >> 4)); target[j+1] = 'A' + (0x0F & source[i]); j += 2; } } static int bind_socket(struct TCP_Server_Info *server) { int rc = 0; if (server->srcaddr.ss_family != AF_UNSPEC) { /* Bind to the specified local IP address */ struct socket *socket = server->ssocket; rc = socket->ops->bind(socket, (struct sockaddr *) &server->srcaddr, sizeof(server->srcaddr)); if (rc < 0) { struct sockaddr_in *saddr4; struct sockaddr_in6 *saddr6; saddr4 = (struct sockaddr_in *)&server->srcaddr; saddr6 = (struct sockaddr_in6 *)&server->srcaddr; if (saddr6->sin6_family == AF_INET6) cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n", &saddr6->sin6_addr, rc); else cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n", &saddr4->sin_addr.s_addr, rc); } } return rc; } static int ip_rfc1001_connect(struct TCP_Server_Info *server) { int rc = 0; /* * some servers require RFC1001 sessinit before sending * negprot - BB check reconnection in case where second * sessinit is sent but no second negprot */ struct rfc1002_session_packet *ses_init_buf; struct smb_hdr *smb_buf; ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet), GFP_KERNEL); if (ses_init_buf) { ses_init_buf->trailer.session_req.called_len = 32; if (server->server_RFC1001_name[0] != 0) rfc1002mangle(ses_init_buf->trailer. session_req.called_name, server->server_RFC1001_name, RFC1001_NAME_LEN_WITH_NULL); else rfc1002mangle(ses_init_buf->trailer. session_req.called_name, DEFAULT_CIFS_CALLED_NAME, RFC1001_NAME_LEN_WITH_NULL); ses_init_buf->trailer.session_req.calling_len = 32; /* * calling name ends in null (byte 16) from old smb * convention. */ if (server->workstation_RFC1001_name[0] != 0) rfc1002mangle(ses_init_buf->trailer. session_req.calling_name, server->workstation_RFC1001_name, RFC1001_NAME_LEN_WITH_NULL); else rfc1002mangle(ses_init_buf->trailer. session_req.calling_name, "LINUX_CIFS_CLNT", RFC1001_NAME_LEN_WITH_NULL); ses_init_buf->trailer.session_req.scope1 = 0; ses_init_buf->trailer.session_req.scope2 = 0; smb_buf = (struct smb_hdr *)ses_init_buf; /* sizeof RFC1002_SESSION_REQUEST with no scope */ smb_buf->smb_buf_length = cpu_to_be32(0x81000044); rc = smb_send(server, smb_buf, 0x44); kfree(ses_init_buf); /* * RFC1001 layer in at least one server * requires very short break before negprot * presumably because not expecting negprot * to follow so fast. This is a simple * solution that works without * complicating the code and causes no * significant slowing down on mount * for everyone else */ usleep_range(1000, 2000); } /* * else the negprot may still work without this * even though malloc failed */ return rc; } static int generic_ip_connect(struct TCP_Server_Info *server) { int rc = 0; __be16 sport; int slen, sfamily; struct socket *socket = server->ssocket; struct sockaddr *saddr; saddr = (struct sockaddr *) &server->dstaddr; if (server->dstaddr.ss_family == AF_INET6) { struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr; sport = ipv6->sin6_port; slen = sizeof(struct sockaddr_in6); sfamily = AF_INET6; cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr, ntohs(sport)); } else { struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr; sport = ipv4->sin_port; slen = sizeof(struct sockaddr_in); sfamily = AF_INET; cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr, ntohs(sport)); } if (socket == NULL) { rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM, IPPROTO_TCP, &socket, 1); if (rc < 0) { cifs_server_dbg(VFS, "Error %d creating socket\n", rc); server->ssocket = NULL; return rc; } /* BB other socket options to set KEEPALIVE, NODELAY? */ cifs_dbg(FYI, "Socket created\n"); server->ssocket = socket; socket->sk->sk_allocation = GFP_NOFS; if (sfamily == AF_INET6) cifs_reclassify_socket6(socket); else cifs_reclassify_socket4(socket); } rc = bind_socket(server); if (rc < 0) return rc; /* * Eventually check for other socket options to change from * the default. sock_setsockopt not used because it expects * user space buffer */ socket->sk->sk_rcvtimeo = 7 * HZ; socket->sk->sk_sndtimeo = 5 * HZ; /* make the bufsizes depend on wsize/rsize and max requests */ if (server->noautotune) { if (socket->sk->sk_sndbuf < (200 * 1024)) socket->sk->sk_sndbuf = 200 * 1024; if (socket->sk->sk_rcvbuf < (140 * 1024)) socket->sk->sk_rcvbuf = 140 * 1024; } if (server->tcp_nodelay) tcp_sock_set_nodelay(socket->sk); cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n", socket->sk->sk_sndbuf, socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo); rc = socket->ops->connect(socket, saddr, slen, server->noblockcnt ? O_NONBLOCK : 0); /* * When mounting SMB root file systems, we do not want to block in * connect. Otherwise bail out and then let cifs_reconnect() perform * reconnect failover - if possible. */ if (server->noblockcnt && rc == -EINPROGRESS) rc = 0; if (rc < 0) { cifs_dbg(FYI, "Error %d connecting to server\n", rc); sock_release(socket); server->ssocket = NULL; return rc; } 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); } 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"); } } } 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); 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; /* 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); if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) && (le64_to_cpu(tcon->fsUnixInfo.Capability) & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) { rc = -EACCES; goto out; } } else 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); 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(&cifs_tcp_ses_lock); mnt_ctx->server->is_dfs_conn = true; spin_unlock(&cifs_tcp_ses_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 (e.g. a DFS share). Return -EREMOTE if it is, * otherwise 0. */ 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) { kfree(full_path); return rc; } 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; } } 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; 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 */ 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); 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; server->origin_fullpath = mnt_ctx->origin_fullpath; server->leaf_fullpath = mnt_ctx->leaf_fullpath; server->current_fullpath = mnt_ctx->leaf_fullpath; 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; 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 == -EREMOTE) 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->tidStatus = CifsGood; tcon->need_reconnect = false; 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); strlcpy(tcon->treeName, tree, sizeof(tcon->treeName)); /* mostly informational -- no need to fail on error here */ kfree(tcon->nativeFileSystem); tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr, bytes_left, is_unicode, nls_codepage); cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem); if ((smb_buffer_response->WordCount == 3) || (smb_buffer_response->WordCount == 7)) /* field is in same location */ tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport); else tcon->Flags = 0; cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags); } cifs_buf_release(smb_buffer); return rc; } static void delayed_free(struct rcu_head *p) { struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu); unload_nls(cifs_sb->local_nls); smb3_cleanup_fs_context(cifs_sb->ctx); kfree(cifs_sb); } void cifs_umount(struct cifs_sb_info *cifs_sb) { struct rb_root *root = &cifs_sb->tlink_tree; struct rb_node *node; struct tcon_link *tlink; cancel_delayed_work_sync(&cifs_sb->prune_tlinks); spin_lock(&cifs_sb->tlink_tree_lock); while ((node = rb_first(root))) { tlink = rb_entry(node, struct tcon_link, tl_rbnode); cifs_get_tlink(tlink); clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); rb_erase(node, root); spin_unlock(&cifs_sb->tlink_tree_lock); cifs_put_tlink(tlink); spin_lock(&cifs_sb->tlink_tree_lock); } spin_unlock(&cifs_sb->tlink_tree_lock); kfree(cifs_sb->prepath); #ifdef CONFIG_CIFS_DFS_UPCALL dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id); #endif call_rcu(&cifs_sb->rcu, delayed_free); } int cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses) { int rc = 0; struct TCP_Server_Info *server = cifs_ses_server(ses); if (!server->ops->need_neg || !server->ops->negotiate) return -ENOSYS; /* only send once per connect */ if (!server->ops->need_neg(server)) return 0; rc = server->ops->negotiate(xid, ses); if (rc == 0) { spin_lock(&GlobalMid_Lock); if (server->tcpStatus == CifsNeedNegotiate) server->tcpStatus = CifsGood; else rc = -EHOSTDOWN; spin_unlock(&GlobalMid_Lock); } return rc; } int cifs_setup_session(const unsigned int xid, struct cifs_ses *ses, struct nls_table *nls_info) { int rc = -ENOSYS; struct TCP_Server_Info *server = cifs_ses_server(ses); if (!ses->binding) { ses->capabilities = server->capabilities; if (!linuxExtEnabled) ses->capabilities &= (~server->vals->cap_unix); if (ses->auth_key.response) { cifs_dbg(FYI, "Free previous auth_key.response = %p\n", ses->auth_key.response); kfree(ses->auth_key.response); ses->auth_key.response = NULL; ses->auth_key.len = 0; } } cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n", server->sec_mode, server->capabilities, server->timeAdj); if (server->ops->sess_setup) rc = server->ops->sess_setup(xid, ses, nls_info); if (rc) cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc); return rc; } static int cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses) { ctx->sectype = ses->sectype; /* krb5 is special, since we don't need username or pw */ if (ctx->sectype == Kerberos) return 0; return cifs_set_cifscreds(ctx, ses); } static struct cifs_tcon * cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid) { int rc; struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb); struct cifs_ses *ses; struct cifs_tcon *tcon = NULL; struct smb3_fs_context *ctx; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (ctx == NULL) return ERR_PTR(-ENOMEM); ctx->local_nls = cifs_sb->local_nls; ctx->linux_uid = fsuid; ctx->cred_uid = fsuid; ctx->UNC = master_tcon->treeName; ctx->retry = master_tcon->retry; ctx->nocase = master_tcon->nocase; ctx->nohandlecache = master_tcon->nohandlecache; ctx->local_lease = master_tcon->local_lease; ctx->no_lease = master_tcon->no_lease; ctx->resilient = master_tcon->use_resilient; ctx->persistent = master_tcon->use_persistent; ctx->handle_timeout = master_tcon->handle_timeout; ctx->no_linux_ext = !master_tcon->unix_ext; ctx->linux_ext = master_tcon->posix_extensions; ctx->sectype = master_tcon->ses->sectype; ctx->sign = master_tcon->ses->sign; ctx->seal = master_tcon->seal; ctx->witness = master_tcon->use_witness; rc = cifs_set_vol_auth(ctx, master_tcon->ses); if (rc) { tcon = ERR_PTR(rc); goto out; } /* get a reference for the same TCP session */ spin_lock(&cifs_tcp_ses_lock); ++master_tcon->ses->server->srv_count; spin_unlock(&cifs_tcp_ses_lock); ses = cifs_get_smb_ses(master_tcon->ses->server, ctx); if (IS_ERR(ses)) { tcon = (struct cifs_tcon *)ses; cifs_put_tcp_session(master_tcon->ses->server, 0); goto out; } tcon = cifs_get_tcon(ses, ctx); if (IS_ERR(tcon)) { cifs_put_smb_ses(ses); goto out; } if (cap_unix(ses)) reset_cifs_unix_caps(0, tcon, NULL, ctx); 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 static void mark_tcon_tcp_ses_for_reconnect(struct cifs_tcon *tcon) { int i; for (i = 0; i < tcon->ses->chan_count; i++) { spin_lock(&GlobalMid_Lock); if (tcon->ses->chans[i].server->tcpStatus != CifsExiting) tcon->ses->chans[i].server->tcpStatus = CifsNeedReconnect; spin_unlock(&GlobalMid_Lock); } } /* 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; } int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, char *tree, struct dfs_cache_tgt_list *tl, struct dfs_info3_param *ref) { 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; bool islink; 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); islink = ref->server_type == DFS_TYPE_LINK; free_dfs_info_param(ref); 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); /* 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, ref, &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); break; } /* 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); free_dfs_info_param(ref); } break; } out: kfree(share); kfree(prefix); return rc; } int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, char *tree, struct dfs_cache_tgt_list *tl, struct dfs_info3_param *ref) { 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, tl, ref); 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; mark_tcon_tcp_ses_for_reconnect(tcon); } 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}; tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL); if (!tree) return -ENOMEM; if (tcon->ipc) { scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname); rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc); goto out; } sb = cifs_get_tcp_super(server); if (IS_ERR(sb)) { rc = PTR_ERR(sb); cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc); goto out; } cifs_sb = CIFS_SB(sb); /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */ if (!server->current_fullpath || dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) { rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls); goto out; } rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, &tl, &ref); out: kfree(tree); cifs_put_tcp_super(sb); return rc; } #else int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc) { const struct smb_version_operations *ops = tcon->ses->server->ops; return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc); } #endif