// SPDX-License-Identifier: LGPL-2.1 /* * * Copyright (C) International Business Machines Corp., 2002,2008 * Author(s): Steve French (sfrench@us.ibm.com) * Jeremy Allison (jra@samba.org) 2006. * */ #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_debug.h" #include "smb2proto.h" #include "smbdirect.h" /* Max number of iovectors we can use off the stack when sending requests. */ #define CIFS_MAX_IOV_SIZE 8 void cifs_wake_up_task(struct mid_q_entry *mid) { if (mid->mid_state == MID_RESPONSE_RECEIVED) mid->mid_state = MID_RESPONSE_READY; wake_up_process(mid->callback_data); } static struct mid_q_entry * alloc_mid(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server) { struct mid_q_entry *temp; if (server == NULL) { cifs_dbg(VFS, "%s: null TCP session\n", __func__); return NULL; } temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS); memset(temp, 0, sizeof(struct mid_q_entry)); kref_init(&temp->refcount); temp->mid = get_mid(smb_buffer); temp->pid = current->pid; temp->command = cpu_to_le16(smb_buffer->Command); cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command); /* easier to use jiffies */ /* when mid allocated can be before when sent */ temp->when_alloc = jiffies; temp->server = server; /* * The default is for the mid to be synchronous, so the * default callback just wakes up the current task. */ get_task_struct(current); temp->creator = current; temp->callback = cifs_wake_up_task; temp->callback_data = current; atomic_inc(&mid_count); temp->mid_state = MID_REQUEST_ALLOCATED; return temp; } void __release_mid(struct kref *refcount) { struct mid_q_entry *midEntry = container_of(refcount, struct mid_q_entry, refcount); #ifdef CONFIG_CIFS_STATS2 __le16 command = midEntry->server->vals->lock_cmd; __u16 smb_cmd = le16_to_cpu(midEntry->command); unsigned long now; unsigned long roundtrip_time; #endif struct TCP_Server_Info *server = midEntry->server; if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) && (midEntry->mid_state == MID_RESPONSE_RECEIVED || midEntry->mid_state == MID_RESPONSE_READY) && server->ops->handle_cancelled_mid) server->ops->handle_cancelled_mid(midEntry, server); midEntry->mid_state = MID_FREE; atomic_dec(&mid_count); if (midEntry->large_buf) cifs_buf_release(midEntry->resp_buf); else cifs_small_buf_release(midEntry->resp_buf); #ifdef CONFIG_CIFS_STATS2 now = jiffies; if (now < midEntry->when_alloc) cifs_server_dbg(VFS, "Invalid mid allocation time\n"); roundtrip_time = now - midEntry->when_alloc; if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) { if (atomic_read(&server->num_cmds[smb_cmd]) == 0) { server->slowest_cmd[smb_cmd] = roundtrip_time; server->fastest_cmd[smb_cmd] = roundtrip_time; } else { if (server->slowest_cmd[smb_cmd] < roundtrip_time) server->slowest_cmd[smb_cmd] = roundtrip_time; else if (server->fastest_cmd[smb_cmd] > roundtrip_time) server->fastest_cmd[smb_cmd] = roundtrip_time; } cifs_stats_inc(&server->num_cmds[smb_cmd]); server->time_per_cmd[smb_cmd] += roundtrip_time; } /* * commands taking longer than one second (default) can be indications * that something is wrong, unless it is quite a slow link or a very * busy server. Note that this calc is unlikely or impossible to wrap * as long as slow_rsp_threshold is not set way above recommended max * value (32767 ie 9 hours) and is generally harmless even if wrong * since only affects debug counters - so leaving the calc as simple * comparison rather than doing multiple conversions and overflow * checks */ if ((slow_rsp_threshold != 0) && time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) && (midEntry->command != command)) { /* * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command * NB: le16_to_cpu returns unsigned so can not be negative below */ if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) cifs_stats_inc(&server->smb2slowcmd[smb_cmd]); trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid, midEntry->when_sent, midEntry->when_received); if (cifsFYI & CIFS_TIMER) { pr_debug("slow rsp: cmd %d mid %llu", midEntry->command, midEntry->mid); cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n", now - midEntry->when_alloc, now - midEntry->when_sent, now - midEntry->when_received); } } #endif put_task_struct(midEntry->creator); mempool_free(midEntry, cifs_mid_poolp); } void delete_mid(struct mid_q_entry *mid) { spin_lock(&mid->server->mid_lock); if (!(mid->mid_flags & MID_DELETED)) { list_del_init(&mid->qhead); mid->mid_flags |= MID_DELETED; } spin_unlock(&mid->server->mid_lock); release_mid(mid); } /* * smb_send_kvec - send an array of kvecs to the server * @server: Server to send the data to * @smb_msg: Message to send * @sent: amount of data sent on socket is stored here * * Our basic "send data to server" function. Should be called with srv_mutex * held. The caller is responsible for handling the results. */ static int smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg, size_t *sent) { int rc = 0; int retries = 0; struct socket *ssocket = server->ssocket; *sent = 0; if (server->noblocksnd) smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; else smb_msg->msg_flags = MSG_NOSIGNAL; while (msg_data_left(smb_msg)) { /* * If blocking send, we try 3 times, since each can block * for 5 seconds. For nonblocking we have to try more * but wait increasing amounts of time allowing time for * socket to clear. The overall time we wait in either * case to send on the socket is about 15 seconds. * Similarly we wait for 15 seconds for a response from * the server in SendReceive[2] for the server to send * a response back for most types of requests (except * SMB Write past end of file which can be slow, and * blocking lock operations). NFS waits slightly longer * than CIFS, but this can make it take longer for * nonresponsive servers to be detected and 15 seconds * is more than enough time for modern networks to * send a packet. In most cases if we fail to send * after the retries we will kill the socket and * reconnect which may clear the network problem. */ rc = sock_sendmsg(ssocket, smb_msg); if (rc == -EAGAIN) { retries++; if (retries >= 14 || (!server->noblocksnd && (retries > 2))) { cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n", ssocket); return -EAGAIN; } msleep(1 << retries); continue; } if (rc < 0) return rc; if (rc == 0) { /* should never happen, letting socket clear before retrying is our only obvious option here */ cifs_server_dbg(VFS, "tcp sent no data\n"); msleep(500); continue; } /* send was at least partially successful */ *sent += rc; retries = 0; /* in case we get ENOSPC on the next send */ } return 0; } unsigned long smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst) { unsigned int i; struct kvec *iov; int nvec; unsigned long buflen = 0; if (!is_smb1(server) && rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) { iov = &rqst->rq_iov[1]; nvec = rqst->rq_nvec - 1; } else { iov = rqst->rq_iov; nvec = rqst->rq_nvec; } /* total up iov array first */ for (i = 0; i < nvec; i++) buflen += iov[i].iov_len; buflen += iov_iter_count(&rqst->rq_iter); return buflen; } static int __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) { int rc; struct kvec *iov; int n_vec; unsigned int send_length = 0; unsigned int i, j; sigset_t mask, oldmask; size_t total_len = 0, sent, size; struct socket *ssocket = server->ssocket; struct msghdr smb_msg = {}; __be32 rfc1002_marker; cifs_in_send_inc(server); if (cifs_rdma_enabled(server)) { /* return -EAGAIN when connecting or reconnecting */ rc = -EAGAIN; if (server->smbd_conn) rc = smbd_send(server, num_rqst, rqst); goto smbd_done; } rc = -EAGAIN; if (ssocket == NULL) goto out; rc = -ERESTARTSYS; if (fatal_signal_pending(current)) { cifs_dbg(FYI, "signal pending before send request\n"); goto out; } rc = 0; /* cork the socket */ tcp_sock_set_cork(ssocket->sk, true); for (j = 0; j < num_rqst; j++) send_length += smb_rqst_len(server, &rqst[j]); rfc1002_marker = cpu_to_be32(send_length); /* * We should not allow signals to interrupt the network send because * any partial send will cause session reconnects thus increasing * latency of system calls and overload a server with unnecessary * requests. */ sigfillset(&mask); sigprocmask(SIG_BLOCK, &mask, &oldmask); /* Generate a rfc1002 marker for SMB2+ */ if (!is_smb1(server)) { struct kvec hiov = { .iov_base = &rfc1002_marker, .iov_len = 4 }; iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, &hiov, 1, 4); rc = smb_send_kvec(server, &smb_msg, &sent); if (rc < 0) goto unmask; total_len += sent; send_length += 4; } cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length); for (j = 0; j < num_rqst; j++) { iov = rqst[j].rq_iov; n_vec = rqst[j].rq_nvec; size = 0; for (i = 0; i < n_vec; i++) { dump_smb(iov[i].iov_base, iov[i].iov_len); size += iov[i].iov_len; } iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, iov, n_vec, size); rc = smb_send_kvec(server, &smb_msg, &sent); if (rc < 0) goto unmask; total_len += sent; if (iov_iter_count(&rqst[j].rq_iter) > 0) { smb_msg.msg_iter = rqst[j].rq_iter; rc = smb_send_kvec(server, &smb_msg, &sent); if (rc < 0) break; total_len += sent; } } unmask: sigprocmask(SIG_SETMASK, &oldmask, NULL); /* * If signal is pending but we have already sent the whole packet to * the server we need to return success status to allow a corresponding * mid entry to be kept in the pending requests queue thus allowing * to handle responses from the server by the client. * * If only part of the packet has been sent there is no need to hide * interrupt because the session will be reconnected anyway, so there * won't be any response from the server to handle. */ if (signal_pending(current) && (total_len != send_length)) { cifs_dbg(FYI, "signal is pending after attempt to send\n"); rc = -ERESTARTSYS; } /* uncork it */ tcp_sock_set_cork(ssocket->sk, false); if ((total_len > 0) && (total_len != send_length)) { cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n", send_length, total_len); /* * If we have only sent part of an SMB then the next SMB could * be taken as the remainder of this one. We need to kill the * socket so the server throws away the partial SMB */ cifs_signal_cifsd_for_reconnect(server, false); trace_smb3_partial_send_reconnect(server->CurrentMid, server->conn_id, server->hostname); } smbd_done: /* * there's hardly any use for the layers above to know the * actual error code here. All they should do at this point is * to retry the connection and hope it goes away. */ if (rc < 0 && rc != -EINTR && rc != -EAGAIN) { cifs_server_dbg(VFS, "Error %d sending data on socket to server\n", rc); rc = -ECONNABORTED; cifs_signal_cifsd_for_reconnect(server, false); } else if (rc > 0) rc = 0; out: cifs_in_send_dec(server); return rc; } struct send_req_vars { struct smb2_transform_hdr tr_hdr; struct smb_rqst rqst[MAX_COMPOUND]; struct kvec iov; }; static int smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst, int flags) { struct send_req_vars *vars; struct smb_rqst *cur_rqst; struct kvec *iov; int rc; if (!(flags & CIFS_TRANSFORM_REQ)) return __smb_send_rqst(server, num_rqst, rqst); if (WARN_ON_ONCE(num_rqst > MAX_COMPOUND - 1)) return -EIO; if (!server->ops->init_transform_rq) { cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n"); return -EIO; } vars = kzalloc(sizeof(*vars), GFP_NOFS); if (!vars) return -ENOMEM; cur_rqst = vars->rqst; iov = &vars->iov; iov->iov_base = &vars->tr_hdr; iov->iov_len = sizeof(vars->tr_hdr); cur_rqst[0].rq_iov = iov; cur_rqst[0].rq_nvec = 1; rc = server->ops->init_transform_rq(server, num_rqst + 1, &cur_rqst[0], rqst); if (rc) goto out; rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]); smb3_free_compound_rqst(num_rqst, &cur_rqst[1]); out: kfree(vars); return rc; } int smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer, unsigned int smb_buf_length) { struct kvec iov[2]; struct smb_rqst rqst = { .rq_iov = iov, .rq_nvec = 2 }; iov[0].iov_base = smb_buffer; iov[0].iov_len = 4; iov[1].iov_base = (char *)smb_buffer + 4; iov[1].iov_len = smb_buf_length; return __smb_send_rqst(server, 1, &rqst); } static int wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits, const int timeout, const int flags, unsigned int *instance) { long rc; int *credits; int optype; long int t; int scredits, in_flight; if (timeout < 0) t = MAX_JIFFY_OFFSET; else t = msecs_to_jiffies(timeout); optype = flags & CIFS_OP_MASK; *instance = 0; credits = server->ops->get_credits_field(server, optype); /* Since an echo is already inflight, no need to wait to send another */ if (*credits <= 0 && optype == CIFS_ECHO_OP) return -EAGAIN; spin_lock(&server->req_lock); if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) { /* oplock breaks must not be held up */ server->in_flight++; if (server->in_flight > server->max_in_flight) server->max_in_flight = server->in_flight; *credits -= 1; *instance = server->reconnect_instance; scredits = *credits; in_flight = server->in_flight; spin_unlock(&server->req_lock); trace_smb3_nblk_credits(server->CurrentMid, server->conn_id, server->hostname, scredits, -1, in_flight); cifs_dbg(FYI, "%s: remove %u credits total=%d\n", __func__, 1, scredits); return 0; } while (1) { spin_unlock(&server->req_lock); spin_lock(&server->srv_lock); if (server->tcpStatus == CifsExiting) { spin_unlock(&server->srv_lock); return -ENOENT; } spin_unlock(&server->srv_lock); spin_lock(&server->req_lock); if (*credits < num_credits) { scredits = *credits; spin_unlock(&server->req_lock); cifs_num_waiters_inc(server); rc = wait_event_killable_timeout(server->request_q, has_credits(server, credits, num_credits), t); cifs_num_waiters_dec(server); if (!rc) { spin_lock(&server->req_lock); scredits = *credits; in_flight = server->in_flight; spin_unlock(&server->req_lock); trace_smb3_credit_timeout(server->CurrentMid, server->conn_id, server->hostname, scredits, num_credits, in_flight); cifs_server_dbg(VFS, "wait timed out after %d ms\n", timeout); return -EBUSY; } if (rc == -ERESTARTSYS) return -ERESTARTSYS; spin_lock(&server->req_lock); } else { /* * For normal commands, reserve the last MAX_COMPOUND * credits to compound requests. * Otherwise these compounds could be permanently * starved for credits by single-credit requests. * * To prevent spinning CPU, block this thread until * there are >MAX_COMPOUND credits available. * But only do this is we already have a lot of * credits in flight to avoid triggering this check * for servers that are slow to hand out credits on * new sessions. */ if (!optype && num_credits == 1 && server->in_flight > 2 * MAX_COMPOUND && *credits <= MAX_COMPOUND) { spin_unlock(&server->req_lock); cifs_num_waiters_inc(server); rc = wait_event_killable_timeout( server->request_q, has_credits(server, credits, MAX_COMPOUND + 1), t); cifs_num_waiters_dec(server); if (!rc) { spin_lock(&server->req_lock); scredits = *credits; in_flight = server->in_flight; spin_unlock(&server->req_lock); trace_smb3_credit_timeout( server->CurrentMid, server->conn_id, server->hostname, scredits, num_credits, in_flight); cifs_server_dbg(VFS, "wait timed out after %d ms\n", timeout); return -EBUSY; } if (rc == -ERESTARTSYS) return -ERESTARTSYS; spin_lock(&server->req_lock); continue; } /* * Can not count locking commands against total * as they are allowed to block on server. */ /* update # of requests on the wire to server */ if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) { *credits -= num_credits; server->in_flight += num_credits; if (server->in_flight > server->max_in_flight) server->max_in_flight = server->in_flight; *instance = server->reconnect_instance; } scredits = *credits; in_flight = server->in_flight; spin_unlock(&server->req_lock); trace_smb3_waitff_credits(server->CurrentMid, server->conn_id, server->hostname, scredits, -(num_credits), in_flight); cifs_dbg(FYI, "%s: remove %u credits total=%d\n", __func__, num_credits, scredits); break; } } return 0; } static int wait_for_free_request(struct TCP_Server_Info *server, const int flags, unsigned int *instance) { return wait_for_free_credits(server, 1, -1, flags, instance); } static int wait_for_compound_request(struct TCP_Server_Info *server, int num, const int flags, unsigned int *instance) { int *credits; int scredits, in_flight; credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK); spin_lock(&server->req_lock); scredits = *credits; in_flight = server->in_flight; if (*credits < num) { /* * If the server is tight on resources or just gives us less * credits for other reasons (e.g. requests are coming out of * order and the server delays granting more credits until it * processes a missing mid) and we exhausted most available * credits there may be situations when we try to send * a compound request but we don't have enough credits. At this * point the client needs to decide if it should wait for * additional credits or fail the request. If at least one * request is in flight there is a high probability that the * server will return enough credits to satisfy this compound * request. * * Return immediately if no requests in flight since we will be * stuck on waiting for credits. */ if (server->in_flight == 0) { spin_unlock(&server->req_lock); trace_smb3_insufficient_credits(server->CurrentMid, server->conn_id, server->hostname, scredits, num, in_flight); cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n", __func__, in_flight, num, scredits); return -EDEADLK; } } spin_unlock(&server->req_lock); return wait_for_free_credits(server, num, 60000, flags, instance); } int cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size, unsigned int *num, struct cifs_credits *credits) { *num = size; credits->value = 0; credits->instance = server->reconnect_instance; return 0; } static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf, struct mid_q_entry **ppmidQ) { spin_lock(&ses->ses_lock); if (ses->ses_status == SES_NEW) { if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) && (in_buf->Command != SMB_COM_NEGOTIATE)) { spin_unlock(&ses->ses_lock); return -EAGAIN; } /* else ok - we are setting up session */ } if (ses->ses_status == SES_EXITING) { /* check if SMB session is bad because we are setting it up */ if (in_buf->Command != SMB_COM_LOGOFF_ANDX) { spin_unlock(&ses->ses_lock); return -EAGAIN; } /* else ok - we are shutting down session */ } spin_unlock(&ses->ses_lock); *ppmidQ = alloc_mid(in_buf, ses->server); if (*ppmidQ == NULL) return -ENOMEM; spin_lock(&ses->server->mid_lock); list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q); spin_unlock(&ses->server->mid_lock); return 0; } static int wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ) { int error; error = wait_event_state(server->response_q, midQ->mid_state != MID_REQUEST_SUBMITTED && midQ->mid_state != MID_RESPONSE_RECEIVED, (TASK_KILLABLE|TASK_FREEZABLE_UNSAFE)); if (error < 0) return -ERESTARTSYS; return 0; } struct mid_q_entry * cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) { int rc; struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base; struct mid_q_entry *mid; if (rqst->rq_iov[0].iov_len != 4 || rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base) return ERR_PTR(-EIO); /* enable signing if server requires it */ if (server->sign) hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; mid = alloc_mid(hdr, server); if (mid == NULL) return ERR_PTR(-ENOMEM); rc = cifs_sign_rqst(rqst, server, &mid->sequence_number); if (rc) { release_mid(mid); return ERR_PTR(rc); } return mid; } /* * Send a SMB request and set the callback function in the mid to handle * the result. Caller is responsible for dealing with timeouts. */ int cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst, mid_receive_t *receive, mid_callback_t *callback, mid_handle_t *handle, void *cbdata, const int flags, const struct cifs_credits *exist_credits) { int rc; struct mid_q_entry *mid; struct cifs_credits credits = { .value = 0, .instance = 0 }; unsigned int instance; int optype; optype = flags & CIFS_OP_MASK; if ((flags & CIFS_HAS_CREDITS) == 0) { rc = wait_for_free_request(server, flags, &instance); if (rc) return rc; credits.value = 1; credits.instance = instance; } else instance = exist_credits->instance; cifs_server_lock(server); /* * We can't use credits obtained from the previous session to send this * request. Check if there were reconnects after we obtained credits and * return -EAGAIN in such cases to let callers handle it. */ if (instance != server->reconnect_instance) { cifs_server_unlock(server); add_credits_and_wake_if(server, &credits, optype); return -EAGAIN; } mid = server->ops->setup_async_request(server, rqst); if (IS_ERR(mid)) { cifs_server_unlock(server); add_credits_and_wake_if(server, &credits, optype); return PTR_ERR(mid); } mid->receive = receive; mid->callback = callback; mid->callback_data = cbdata; mid->handle = handle; mid->mid_state = MID_REQUEST_SUBMITTED; /* put it on the pending_mid_q */ spin_lock(&server->mid_lock); list_add_tail(&mid->qhead, &server->pending_mid_q); spin_unlock(&server->mid_lock); /* * Need to store the time in mid before calling I/O. For call_async, * I/O response may come back and free the mid entry on another thread. */ cifs_save_when_sent(mid); rc = smb_send_rqst(server, 1, rqst, flags); if (rc < 0) { revert_current_mid(server, mid->credits); server->sequence_number -= 2; delete_mid(mid); } cifs_server_unlock(server); if (rc == 0) return 0; add_credits_and_wake_if(server, &credits, optype); return rc; } /* * * Send an SMB Request. No response info (other than return code) * needs to be parsed. * * flags indicate the type of request buffer and how long to wait * and whether to log NT STATUS code (error) before mapping it to POSIX error * */ int SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses, char *in_buf, int flags) { int rc; struct kvec iov[1]; struct kvec rsp_iov; int resp_buf_type; iov[0].iov_base = in_buf; iov[0].iov_len = get_rfc1002_length(in_buf) + 4; flags |= CIFS_NO_RSP_BUF; rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov); cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc); return rc; } static int cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server) { int rc = 0; cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n", __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state); spin_lock(&server->mid_lock); switch (mid->mid_state) { case MID_RESPONSE_READY: spin_unlock(&server->mid_lock); return rc; case MID_RETRY_NEEDED: rc = -EAGAIN; break; case MID_RESPONSE_MALFORMED: rc = -EIO; break; case MID_SHUTDOWN: rc = -EHOSTDOWN; break; default: if (!(mid->mid_flags & MID_DELETED)) { list_del_init(&mid->qhead); mid->mid_flags |= MID_DELETED; } spin_unlock(&server->mid_lock); cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n", __func__, mid->mid, mid->mid_state); rc = -EIO; goto sync_mid_done; } spin_unlock(&server->mid_lock); sync_mid_done: release_mid(mid); return rc; } static inline int send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst, struct mid_q_entry *mid) { return server->ops->send_cancel ? server->ops->send_cancel(server, rqst, mid) : 0; } int cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, bool log_error) { unsigned int len = get_rfc1002_length(mid->resp_buf) + 4; dump_smb(mid->resp_buf, min_t(u32, 92, len)); /* convert the length into a more usable form */ if (server->sign) { struct kvec iov[2]; int rc = 0; struct smb_rqst rqst = { .rq_iov = iov, .rq_nvec = 2 }; iov[0].iov_base = mid->resp_buf; iov[0].iov_len = 4; iov[1].iov_base = (char *)mid->resp_buf + 4; iov[1].iov_len = len - 4; /* FIXME: add code to kill session */ rc = cifs_verify_signature(&rqst, server, mid->sequence_number); if (rc) cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n", rc); } /* BB special case reconnect tid and uid here? */ return map_and_check_smb_error(mid, log_error); } struct mid_q_entry * cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored, struct smb_rqst *rqst) { int rc; struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base; struct mid_q_entry *mid; if (rqst->rq_iov[0].iov_len != 4 || rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base) return ERR_PTR(-EIO); rc = allocate_mid(ses, hdr, &mid); if (rc) return ERR_PTR(rc); rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number); if (rc) { delete_mid(mid); return ERR_PTR(rc); } return mid; } static void cifs_compound_callback(struct mid_q_entry *mid) { struct TCP_Server_Info *server = mid->server; struct cifs_credits credits; credits.value = server->ops->get_credits(mid); credits.instance = server->reconnect_instance; add_credits(server, &credits, mid->optype); if (mid->mid_state == MID_RESPONSE_RECEIVED) mid->mid_state = MID_RESPONSE_READY; } static void cifs_compound_last_callback(struct mid_q_entry *mid) { cifs_compound_callback(mid); cifs_wake_up_task(mid); } static void cifs_cancelled_callback(struct mid_q_entry *mid) { cifs_compound_callback(mid); release_mid(mid); } /* * Return a channel (master if none) of @ses that can be used to send * regular requests. * * If we are currently binding a new channel (negprot/sess.setup), * return the new incomplete channel. */ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses) { uint index = 0; unsigned int min_in_flight = UINT_MAX, max_in_flight = 0; struct TCP_Server_Info *server = NULL; int i; if (!ses) return NULL; spin_lock(&ses->chan_lock); for (i = 0; i < ses->chan_count; i++) { server = ses->chans[i].server; if (!server || server->terminate) continue; if (CIFS_CHAN_NEEDS_RECONNECT(ses, i)) continue; /* * strictly speaking, we should pick up req_lock to read * server->in_flight. But it shouldn't matter much here if we * race while reading this data. The worst that can happen is * that we could use a channel that's not least loaded. Avoiding * taking the lock could help reduce wait time, which is * important for this function */ if (server->in_flight < min_in_flight) { min_in_flight = server->in_flight; index = i; } if (server->in_flight > max_in_flight) max_in_flight = server->in_flight; } /* if all channels are equally loaded, fall back to round-robin */ if (min_in_flight == max_in_flight) { index = (uint)atomic_inc_return(&ses->chan_seq); index %= ses->chan_count; } server = ses->chans[index].server; spin_unlock(&ses->chan_lock); return server; } int compound_send_recv(const unsigned int xid, struct cifs_ses *ses, struct TCP_Server_Info *server, const int flags, const int num_rqst, struct smb_rqst *rqst, int *resp_buf_type, struct kvec *resp_iov) { int i, j, optype, rc = 0; struct mid_q_entry *midQ[MAX_COMPOUND]; bool cancelled_mid[MAX_COMPOUND] = {false}; struct cifs_credits credits[MAX_COMPOUND] = { { .value = 0, .instance = 0 } }; unsigned int instance; char *buf; optype = flags & CIFS_OP_MASK; for (i = 0; i < num_rqst; i++) resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */ if (!ses || !ses->server || !server) { cifs_dbg(VFS, "Null session\n"); return -EIO; } spin_lock(&server->srv_lock); if (server->tcpStatus == CifsExiting) { spin_unlock(&server->srv_lock); return -ENOENT; } spin_unlock(&server->srv_lock); /* * Wait for all the requests to become available. * This approach still leaves the possibility to be stuck waiting for * credits if the server doesn't grant credits to the outstanding * requests and if the client is completely idle, not generating any * other requests. * This can be handled by the eventual session reconnect. */ rc = wait_for_compound_request(server, num_rqst, flags, &instance); if (rc) return rc; for (i = 0; i < num_rqst; i++) { credits[i].value = 1; credits[i].instance = instance; } /* * Make sure that we sign in the same order that we send on this socket * and avoid races inside tcp sendmsg code that could cause corruption * of smb data. */ cifs_server_lock(server); /* * All the parts of the compound chain belong obtained credits from the * same session. We can not use credits obtained from the previous * session to send this request. Check if there were reconnects after * we obtained credits and return -EAGAIN in such cases to let callers * handle it. */ if (instance != server->reconnect_instance) { cifs_server_unlock(server); for (j = 0; j < num_rqst; j++) add_credits(server, &credits[j], optype); return -EAGAIN; } for (i = 0; i < num_rqst; i++) { midQ[i] = server->ops->setup_request(ses, server, &rqst[i]); if (IS_ERR(midQ[i])) { revert_current_mid(server, i); for (j = 0; j < i; j++) delete_mid(midQ[j]); cifs_server_unlock(server); /* Update # of requests on wire to server */ for (j = 0; j < num_rqst; j++) add_credits(server, &credits[j], optype); return PTR_ERR(midQ[i]); } midQ[i]->mid_state = MID_REQUEST_SUBMITTED; midQ[i]->optype = optype; /* * Invoke callback for every part of the compound chain * to calculate credits properly. Wake up this thread only when * the last element is received. */ if (i < num_rqst - 1) midQ[i]->callback = cifs_compound_callback; else midQ[i]->callback = cifs_compound_last_callback; } rc = smb_send_rqst(server, num_rqst, rqst, flags); for (i = 0; i < num_rqst; i++) cifs_save_when_sent(midQ[i]); if (rc < 0) { revert_current_mid(server, num_rqst); server->sequence_number -= 2; } cifs_server_unlock(server); /* * If sending failed for some reason or it is an oplock break that we * will not receive a response to - return credits back */ if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) { for (i = 0; i < num_rqst; i++) add_credits(server, &credits[i], optype); goto out; } /* * At this point the request is passed to the network stack - we assume * that any credits taken from the server structure on the client have * been spent and we can't return them back. Once we receive responses * we will collect credits granted by the server in the mid callbacks * and add those credits to the server structure. */ /* * Compounding is never used during session establish. */ spin_lock(&ses->ses_lock); if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) { spin_unlock(&ses->ses_lock); cifs_server_lock(server); smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec); cifs_server_unlock(server); spin_lock(&ses->ses_lock); } spin_unlock(&ses->ses_lock); for (i = 0; i < num_rqst; i++) { rc = wait_for_response(server, midQ[i]); if (rc != 0) break; } if (rc != 0) { for (; i < num_rqst; i++) { cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n", midQ[i]->mid, le16_to_cpu(midQ[i]->command)); send_cancel(server, &rqst[i], midQ[i]); spin_lock(&server->mid_lock); midQ[i]->mid_flags |= MID_WAIT_CANCELLED; if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED || midQ[i]->mid_state == MID_RESPONSE_RECEIVED) { midQ[i]->callback = cifs_cancelled_callback; cancelled_mid[i] = true; credits[i].value = 0; } spin_unlock(&server->mid_lock); } } for (i = 0; i < num_rqst; i++) { if (rc < 0) goto out; rc = cifs_sync_mid_result(midQ[i], server); if (rc != 0) { /* mark this mid as cancelled to not free it below */ cancelled_mid[i] = true; goto out; } if (!midQ[i]->resp_buf || midQ[i]->mid_state != MID_RESPONSE_READY) { rc = -EIO; cifs_dbg(FYI, "Bad MID state?\n"); goto out; } buf = (char *)midQ[i]->resp_buf; resp_iov[i].iov_base = buf; resp_iov[i].iov_len = midQ[i]->resp_buf_size + HEADER_PREAMBLE_SIZE(server); if (midQ[i]->large_buf) resp_buf_type[i] = CIFS_LARGE_BUFFER; else resp_buf_type[i] = CIFS_SMALL_BUFFER; rc = server->ops->check_receive(midQ[i], server, flags & CIFS_LOG_ERROR); /* mark it so buf will not be freed by delete_mid */ if ((flags & CIFS_NO_RSP_BUF) == 0) midQ[i]->resp_buf = NULL; } /* * Compounding is never used during session establish. */ spin_lock(&ses->ses_lock); if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) { struct kvec iov = { .iov_base = resp_iov[0].iov_base, .iov_len = resp_iov[0].iov_len }; spin_unlock(&ses->ses_lock); cifs_server_lock(server); smb311_update_preauth_hash(ses, server, &iov, 1); cifs_server_unlock(server); spin_lock(&ses->ses_lock); } spin_unlock(&ses->ses_lock); out: /* * This will dequeue all mids. After this it is important that the * demultiplex_thread will not process any of these mids any futher. * This is prevented above by using a noop callback that will not * wake this thread except for the very last PDU. */ for (i = 0; i < num_rqst; i++) { if (!cancelled_mid[i]) delete_mid(midQ[i]); } return rc; } int cifs_send_recv(const unsigned int xid, struct cifs_ses *ses, struct TCP_Server_Info *server, struct smb_rqst *rqst, int *resp_buf_type, const int flags, struct kvec *resp_iov) { return compound_send_recv(xid, ses, server, flags, 1, rqst, resp_buf_type, resp_iov); } int SendReceive2(const unsigned int xid, struct cifs_ses *ses, struct kvec *iov, int n_vec, int *resp_buf_type /* ret */, const int flags, struct kvec *resp_iov) { struct smb_rqst rqst; struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov; int rc; if (n_vec + 1 > CIFS_MAX_IOV_SIZE) { new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec), GFP_KERNEL); if (!new_iov) { /* otherwise cifs_send_recv below sets resp_buf_type */ *resp_buf_type = CIFS_NO_BUFFER; return -ENOMEM; } } else new_iov = s_iov; /* 1st iov is a RFC1001 length followed by the rest of the packet */ memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec)); new_iov[0].iov_base = new_iov[1].iov_base; new_iov[0].iov_len = 4; new_iov[1].iov_base += 4; new_iov[1].iov_len -= 4; memset(&rqst, 0, sizeof(struct smb_rqst)); rqst.rq_iov = new_iov; rqst.rq_nvec = n_vec + 1; rc = cifs_send_recv(xid, ses, ses->server, &rqst, resp_buf_type, flags, resp_iov); if (n_vec + 1 > CIFS_MAX_IOV_SIZE) kfree(new_iov); return rc; } int SendReceive(const unsigned int xid, struct cifs_ses *ses, struct smb_hdr *in_buf, struct smb_hdr *out_buf, int *pbytes_returned, const int flags) { int rc = 0; struct mid_q_entry *midQ; unsigned int len = be32_to_cpu(in_buf->smb_buf_length); struct kvec iov = { .iov_base = in_buf, .iov_len = len }; struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 }; struct cifs_credits credits = { .value = 1, .instance = 0 }; struct TCP_Server_Info *server; if (ses == NULL) { cifs_dbg(VFS, "Null smb session\n"); return -EIO; } server = ses->server; if (server == NULL) { cifs_dbg(VFS, "Null tcp session\n"); return -EIO; } spin_lock(&server->srv_lock); if (server->tcpStatus == CifsExiting) { spin_unlock(&server->srv_lock); return -ENOENT; } spin_unlock(&server->srv_lock); /* Ensure that we do not send more than 50 overlapping requests to the same server. We may make this configurable later or use ses->maxReq */ if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) { cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n", len); return -EIO; } rc = wait_for_free_request(server, flags, &credits.instance); if (rc) return rc; /* make sure that we sign in the same order that we send on this socket and avoid races inside tcp sendmsg code that could cause corruption of smb data */ cifs_server_lock(server); rc = allocate_mid(ses, in_buf, &midQ); if (rc) { cifs_server_unlock(server); /* Update # of requests on wire to server */ add_credits(server, &credits, 0); return rc; } rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number); if (rc) { cifs_server_unlock(server); goto out; } midQ->mid_state = MID_REQUEST_SUBMITTED; rc = smb_send(server, in_buf, len); cifs_save_when_sent(midQ); if (rc < 0) server->sequence_number -= 2; cifs_server_unlock(server); if (rc < 0) goto out; rc = wait_for_response(server, midQ); if (rc != 0) { send_cancel(server, &rqst, midQ); spin_lock(&server->mid_lock); if (midQ->mid_state == MID_REQUEST_SUBMITTED || midQ->mid_state == MID_RESPONSE_RECEIVED) { /* no longer considered to be "in-flight" */ midQ->callback = release_mid; spin_unlock(&server->mid_lock); add_credits(server, &credits, 0); return rc; } spin_unlock(&server->mid_lock); } rc = cifs_sync_mid_result(midQ, server); if (rc != 0) { add_credits(server, &credits, 0); return rc; } if (!midQ->resp_buf || !out_buf || midQ->mid_state != MID_RESPONSE_READY) { rc = -EIO; cifs_server_dbg(VFS, "Bad MID state?\n"); goto out; } *pbytes_returned = get_rfc1002_length(midQ->resp_buf); memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4); rc = cifs_check_receive(midQ, server, 0); out: delete_mid(midQ); add_credits(server, &credits, 0); return rc; } /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows blocking lock to return. */ static int send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon, struct smb_hdr *in_buf, struct smb_hdr *out_buf) { int bytes_returned; struct cifs_ses *ses = tcon->ses; LOCK_REQ *pSMB = (LOCK_REQ *)in_buf; /* We just modify the current in_buf to change the type of lock from LOCKING_ANDX_SHARED_LOCK or LOCKING_ANDX_EXCLUSIVE_LOCK to LOCKING_ANDX_CANCEL_LOCK. */ pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES; pSMB->Timeout = 0; pSMB->hdr.Mid = get_next_mid(ses->server); return SendReceive(xid, ses, in_buf, out_buf, &bytes_returned, 0); } int SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon, struct smb_hdr *in_buf, struct smb_hdr *out_buf, int *pbytes_returned) { int rc = 0; int rstart = 0; struct mid_q_entry *midQ; struct cifs_ses *ses; unsigned int len = be32_to_cpu(in_buf->smb_buf_length); struct kvec iov = { .iov_base = in_buf, .iov_len = len }; struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 }; unsigned int instance; struct TCP_Server_Info *server; if (tcon == NULL || tcon->ses == NULL) { cifs_dbg(VFS, "Null smb session\n"); return -EIO; } ses = tcon->ses; server = ses->server; if (server == NULL) { cifs_dbg(VFS, "Null tcp session\n"); return -EIO; } spin_lock(&server->srv_lock); if (server->tcpStatus == CifsExiting) { spin_unlock(&server->srv_lock); return -ENOENT; } spin_unlock(&server->srv_lock); /* Ensure that we do not send more than 50 overlapping requests to the same server. We may make this configurable later or use ses->maxReq */ if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) { cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n", len); return -EIO; } rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance); if (rc) return rc; /* make sure that we sign in the same order that we send on this socket and avoid races inside tcp sendmsg code that could cause corruption of smb data */ cifs_server_lock(server); rc = allocate_mid(ses, in_buf, &midQ); if (rc) { cifs_server_unlock(server); return rc; } rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number); if (rc) { delete_mid(midQ); cifs_server_unlock(server); return rc; } midQ->mid_state = MID_REQUEST_SUBMITTED; rc = smb_send(server, in_buf, len); cifs_save_when_sent(midQ); if (rc < 0) server->sequence_number -= 2; cifs_server_unlock(server); if (rc < 0) { delete_mid(midQ); return rc; } /* Wait for a reply - allow signals to interrupt. */ rc = wait_event_interruptible(server->response_q, (!(midQ->mid_state == MID_REQUEST_SUBMITTED || midQ->mid_state == MID_RESPONSE_RECEIVED)) || ((server->tcpStatus != CifsGood) && (server->tcpStatus != CifsNew))); /* Were we interrupted by a signal ? */ spin_lock(&server->srv_lock); if ((rc == -ERESTARTSYS) && (midQ->mid_state == MID_REQUEST_SUBMITTED || midQ->mid_state == MID_RESPONSE_RECEIVED) && ((server->tcpStatus == CifsGood) || (server->tcpStatus == CifsNew))) { spin_unlock(&server->srv_lock); if (in_buf->Command == SMB_COM_TRANSACTION2) { /* POSIX lock. We send a NT_CANCEL SMB to cause the blocking lock to return. */ rc = send_cancel(server, &rqst, midQ); if (rc) { delete_mid(midQ); return rc; } } else { /* Windows lock. We send a LOCKINGX_CANCEL_LOCK to cause the blocking lock to return. */ rc = send_lock_cancel(xid, tcon, in_buf, out_buf); /* If we get -ENOLCK back the lock may have already been removed. Don't exit in this case. */ if (rc && rc != -ENOLCK) { delete_mid(midQ); return rc; } } rc = wait_for_response(server, midQ); if (rc) { send_cancel(server, &rqst, midQ); spin_lock(&server->mid_lock); if (midQ->mid_state == MID_REQUEST_SUBMITTED || midQ->mid_state == MID_RESPONSE_RECEIVED) { /* no longer considered to be "in-flight" */ midQ->callback = release_mid; spin_unlock(&server->mid_lock); return rc; } spin_unlock(&server->mid_lock); } /* We got the response - restart system call. */ rstart = 1; spin_lock(&server->srv_lock); } spin_unlock(&server->srv_lock); rc = cifs_sync_mid_result(midQ, server); if (rc != 0) return rc; /* rcvd frame is ok */ if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_READY) { rc = -EIO; cifs_tcon_dbg(VFS, "Bad MID state?\n"); goto out; } *pbytes_returned = get_rfc1002_length(midQ->resp_buf); memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4); rc = cifs_check_receive(midQ, server, 0); out: delete_mid(midQ); if (rstart && rc == -EACCES) return -ERESTARTSYS; return rc; } /* * Discard any remaining data in the current SMB. To do this, we borrow the * current bigbuf. */ int cifs_discard_remaining_data(struct TCP_Server_Info *server) { unsigned int rfclen = server->pdu_size; size_t remaining = rfclen + HEADER_PREAMBLE_SIZE(server) - server->total_read; while (remaining > 0) { ssize_t length; length = cifs_discard_from_socket(server, min_t(size_t, remaining, CIFSMaxBufSize + MAX_HEADER_SIZE(server))); if (length < 0) return length; server->total_read += length; remaining -= length; } return 0; } static int __cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid, bool malformed) { int length; length = cifs_discard_remaining_data(server); dequeue_mid(mid, malformed); mid->resp_buf = server->smallbuf; server->smallbuf = NULL; return length; } static int cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid) { struct cifs_readdata *rdata = mid->callback_data; return __cifs_readv_discard(server, mid, rdata->result); } int cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) { int length, len; unsigned int data_offset, data_len; struct cifs_readdata *rdata = mid->callback_data; char *buf = server->smallbuf; unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server); bool use_rdma_mr = false; cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n", __func__, mid->mid, rdata->offset, rdata->bytes); /* * read the rest of READ_RSP header (sans Data array), or whatever we * can if there's not enough data. At this point, we've read down to * the Mid. */ len = min_t(unsigned int, buflen, server->vals->read_rsp_size) - HEADER_SIZE(server) + 1; length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1, len); if (length < 0) return length; server->total_read += length; if (server->ops->is_session_expired && server->ops->is_session_expired(buf)) { cifs_reconnect(server, true); return -1; } if (server->ops->is_status_pending && server->ops->is_status_pending(buf, server)) { cifs_discard_remaining_data(server); return -1; } /* set up first two iov for signature check and to get credits */ rdata->iov[0].iov_base = buf; rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server); rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server); rdata->iov[1].iov_len = server->total_read - HEADER_PREAMBLE_SIZE(server); cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n", rdata->iov[0].iov_base, rdata->iov[0].iov_len); cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n", rdata->iov[1].iov_base, rdata->iov[1].iov_len); /* Was the SMB read successful? */ rdata->result = server->ops->map_error(buf, false); if (rdata->result != 0) { cifs_dbg(FYI, "%s: server returned error %d\n", __func__, rdata->result); /* normal error on read response */ return __cifs_readv_discard(server, mid, false); } /* Is there enough to get to the rest of the READ_RSP header? */ if (server->total_read < server->vals->read_rsp_size) { cifs_dbg(FYI, "%s: server returned short header. got=%u expected=%zu\n", __func__, server->total_read, server->vals->read_rsp_size); rdata->result = -EIO; return cifs_readv_discard(server, mid); } data_offset = server->ops->read_data_offset(buf) + HEADER_PREAMBLE_SIZE(server); if (data_offset < server->total_read) { /* * win2k8 sometimes sends an offset of 0 when the read * is beyond the EOF. Treat it as if the data starts just after * the header. */ cifs_dbg(FYI, "%s: data offset (%u) inside read response header\n", __func__, data_offset); data_offset = server->total_read; } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) { /* data_offset is beyond the end of smallbuf */ cifs_dbg(FYI, "%s: data offset (%u) beyond end of smallbuf\n", __func__, data_offset); rdata->result = -EIO; return cifs_readv_discard(server, mid); } cifs_dbg(FYI, "%s: total_read=%u data_offset=%u\n", __func__, server->total_read, data_offset); len = data_offset - server->total_read; if (len > 0) { /* read any junk before data into the rest of smallbuf */ length = cifs_read_from_socket(server, buf + server->total_read, len); if (length < 0) return length; server->total_read += length; } /* how much data is in the response? */ #ifdef CONFIG_CIFS_SMB_DIRECT use_rdma_mr = rdata->mr; #endif data_len = server->ops->read_data_length(buf, use_rdma_mr); if (!use_rdma_mr && (data_offset + data_len > buflen)) { /* data_len is corrupt -- discard frame */ rdata->result = -EIO; return cifs_readv_discard(server, mid); } #ifdef CONFIG_CIFS_SMB_DIRECT if (rdata->mr) length = data_len; /* An RDMA read is already done. */ else #endif length = cifs_read_iter_from_socket(server, &rdata->iter, data_len); if (length > 0) rdata->got_bytes += length; server->total_read += length; cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n", server->total_read, buflen, data_len); /* discard anything left over */ if (server->total_read < buflen) return cifs_readv_discard(server, mid); dequeue_mid(mid, false); mid->resp_buf = server->smallbuf; server->smallbuf = NULL; return length; }