--- /dev/null
+/*
+ * fs/cifs/transport.c
+ *
+ * Copyright (C) International Business Machines Corp., 2002,2008
+ * Author(s): Steve French (sfrench@us.ibm.com)
+ * Jeremy Allison (jra@samba.org) 2006.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/gfp.h>
+#include <linux/wait.h>
+#include <linux/net.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/tcp.h>
+#include <linux/highmem.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <linux/mempool.h>
+#include "cifspdu.h"
+#include "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+
+void
+cifs_wake_up_task(struct mid_q_entry *mid)
+{
+ wake_up_process(mid->callback_data);
+}
+
+struct mid_q_entry *
+AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
+{
+ struct mid_q_entry *temp;
+
+ if (server == NULL) {
+ cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
+ return NULL;
+ }
+
+ temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
+ if (temp == NULL)
+ return temp;
+ else {
+ memset(temp, 0, sizeof(struct mid_q_entry));
+ 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);
+ /* do_gettimeofday(&temp->when_sent);*/ /* 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.
+ */
+ temp->callback = cifs_wake_up_task;
+ temp->callback_data = current;
+ }
+
+ atomic_inc(&midCount);
+ temp->mid_state = MID_REQUEST_ALLOCATED;
+ return temp;
+}
+
+void
+DeleteMidQEntry(struct mid_q_entry *midEntry)
+{
+#ifdef CONFIG_CIFS_STATS2
+ __le16 command = midEntry->server->vals->lock_cmd;
+ unsigned long now;
+#endif
+ midEntry->mid_state = MID_FREE;
+ atomic_dec(&midCount);
+ if (midEntry->large_buf)
+ cifs_buf_release(midEntry->resp_buf);
+ else
+ cifs_small_buf_release(midEntry->resp_buf);
+#ifdef CONFIG_CIFS_STATS2
+ now = jiffies;
+ /* commands taking longer than one second are indications that
+ something is wrong, unless it is quite a slow link or server */
+ if ((now - midEntry->when_alloc) > HZ) {
+ if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) {
+ pr_debug(" CIFS slow rsp: cmd %d mid %llu",
+ midEntry->command, midEntry->mid);
+ pr_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
+ now - midEntry->when_alloc,
+ now - midEntry->when_sent,
+ now - midEntry->when_received);
+ }
+ }
+#endif
+ mempool_free(midEntry, cifs_mid_poolp);
+}
+
+void
+cifs_delete_mid(struct mid_q_entry *mid)
+{
+ spin_lock(&GlobalMid_Lock);
+ list_del(&mid->qhead);
+ spin_unlock(&GlobalMid_Lock);
+
+ DeleteMidQEntry(mid);
+}
+
+/*
+ * smb_send_kvec - send an array of kvecs to the server
+ * @server: Server to send the data to
+ * @iov: Pointer to array of kvecs
+ * @n_vec: length of kvec array
+ * @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 kvec *iov, size_t n_vec,
+ size_t *sent)
+{
+ int rc = 0;
+ int i = 0;
+ struct msghdr smb_msg;
+ unsigned int remaining;
+ size_t first_vec = 0;
+ struct socket *ssocket = server->ssocket;
+
+ *sent = 0;
+
+ smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
+ smb_msg.msg_namelen = sizeof(struct sockaddr);
+ smb_msg.msg_control = NULL;
+ smb_msg.msg_controllen = 0;
+ if (server->noblocksnd)
+ smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
+ else
+ smb_msg.msg_flags = MSG_NOSIGNAL;
+
+ remaining = 0;
+ for (i = 0; i < n_vec; i++)
+ remaining += iov[i].iov_len;
+
+ i = 0;
+ while (remaining) {
+ /*
+ * 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 = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
+ n_vec - first_vec, remaining);
+ if (rc == -EAGAIN) {
+ i++;
+ if (i >= 14 || (!server->noblocksnd && (i > 2))) {
+ cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
+ ssocket);
+ rc = -EAGAIN;
+ break;
+ }
+ msleep(1 << i);
+ continue;
+ }
+
+ if (rc < 0)
+ break;
+
+ /* send was at least partially successful */
+ *sent += rc;
+
+ if (rc == remaining) {
+ remaining = 0;
+ break;
+ }
+
+ if (rc > remaining) {
+ cifs_dbg(VFS, "sent %d requested %d\n", rc, remaining);
+ break;
+ }
+
+ if (rc == 0) {
+ /* should never happen, letting socket clear before
+ retrying is our only obvious option here */
+ cifs_dbg(VFS, "tcp sent no data\n");
+ msleep(500);
+ continue;
+ }
+
+ remaining -= rc;
+
+ /* the line below resets i */
+ for (i = first_vec; i < n_vec; i++) {
+ if (iov[i].iov_len) {
+ if (rc > iov[i].iov_len) {
+ rc -= iov[i].iov_len;
+ iov[i].iov_len = 0;
+ } else {
+ iov[i].iov_base += rc;
+ iov[i].iov_len -= rc;
+ first_vec = i;
+ break;
+ }
+ }
+ }
+
+ i = 0; /* in case we get ENOSPC on the next send */
+ rc = 0;
+ }
+ return rc;
+}
+
+/**
+ * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec
+ * @rqst: pointer to smb_rqst
+ * @idx: index into the array of the page
+ * @iov: pointer to struct kvec that will hold the result
+ *
+ * Helper function to convert a slot in the rqst->rq_pages array into a kvec.
+ * The page will be kmapped and the address placed into iov_base. The length
+ * will then be adjusted according to the ptailoff.
+ */
+void
+cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
+ struct kvec *iov)
+{
+ /*
+ * FIXME: We could avoid this kmap altogether if we used
+ * kernel_sendpage instead of kernel_sendmsg. That will only
+ * work if signing is disabled though as sendpage inlines the
+ * page directly into the fraglist. If userspace modifies the
+ * page after we calculate the signature, then the server will
+ * reject it and may break the connection. kernel_sendmsg does
+ * an extra copy of the data and avoids that issue.
+ */
+ iov->iov_base = kmap(rqst->rq_pages[idx]);
+
+ /* if last page, don't send beyond this offset into page */
+ if (idx == (rqst->rq_npages - 1))
+ iov->iov_len = rqst->rq_tailsz;
+ else
+ iov->iov_len = rqst->rq_pagesz;
+}
+
+static unsigned long
+rqst_len(struct smb_rqst *rqst)
+{
+ unsigned int i;
+ struct kvec *iov = rqst->rq_iov;
+ unsigned long buflen = 0;
+
+ /* total up iov array first */
+ for (i = 0; i < rqst->rq_nvec; i++)
+ buflen += iov[i].iov_len;
+
+ /* add in the page array if there is one */
+ if (rqst->rq_npages) {
+ buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
+ buflen += rqst->rq_tailsz;
+ }
+
+ return buflen;
+}
+
+static int
+smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
+{
+ int rc;
+ struct kvec *iov = rqst->rq_iov;
+ int n_vec = rqst->rq_nvec;
+ unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
+ unsigned long send_length;
+ unsigned int i;
+ size_t total_len = 0, sent;
+ struct socket *ssocket = server->ssocket;
+ int val = 1;
+
+ if (ssocket == NULL)
+ return -ENOTSOCK;
+
+ /* sanity check send length */
+ send_length = rqst_len(rqst);
+ if (send_length != smb_buf_length + 4) {
+ WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
+ send_length, smb_buf_length);
+ return -EIO;
+ }
+
+ cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
+ dump_smb(iov[0].iov_base, iov[0].iov_len);
+
+ /* cork the socket */
+ kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
+ (char *)&val, sizeof(val));
+
+ rc = smb_send_kvec(server, iov, n_vec, &sent);
+ if (rc < 0)
+ goto uncork;
+
+ total_len += sent;
+
+ /* now walk the page array and send each page in it */
+ for (i = 0; i < rqst->rq_npages; i++) {
+ struct kvec p_iov;
+
+ cifs_rqst_page_to_kvec(rqst, i, &p_iov);
+ rc = smb_send_kvec(server, &p_iov, 1, &sent);
+ kunmap(rqst->rq_pages[i]);
+ if (rc < 0)
+ break;
+
+ total_len += sent;
+ }
+
+uncork:
+ /* uncork it */
+ val = 0;
+ kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
+ (char *)&val, sizeof(val));
+
+ if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
+ cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
+ smb_buf_length + 4, 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
+ */
+ server->tcpStatus = CifsNeedReconnect;
+ }
+
+ if (rc < 0 && rc != -EINTR)
+ cifs_dbg(VFS, "Error %d sending data on socket to server\n",
+ rc);
+ else
+ rc = 0;
+
+ return rc;
+}
+
+static int
+smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
+{
+ struct smb_rqst rqst = { .rq_iov = iov,
+ .rq_nvec = n_vec };
+
+ return smb_send_rqst(server, &rqst);
+}
+
+int
+smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
+ unsigned int smb_buf_length)
+{
+ struct kvec iov;
+
+ iov.iov_base = smb_buffer;
+ iov.iov_len = smb_buf_length + 4;
+
+ return smb_sendv(server, &iov, 1);
+}
+
+static int
+wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
+ int *credits)
+{
+ int rc;
+
+ spin_lock(&server->req_lock);
+ if (timeout == CIFS_ASYNC_OP) {
+ /* oplock breaks must not be held up */
+ server->in_flight++;
+ *credits -= 1;
+ spin_unlock(&server->req_lock);
+ return 0;
+ }
+
+ while (1) {
+ if (*credits <= 0) {
+ spin_unlock(&server->req_lock);
+ cifs_num_waiters_inc(server);
+ rc = wait_event_killable(server->request_q,
+ has_credits(server, credits));
+ cifs_num_waiters_dec(server);
+ if (rc)
+ return rc;
+ spin_lock(&server->req_lock);
+ } else {
+ if (server->tcpStatus == CifsExiting) {
+ spin_unlock(&server->req_lock);
+ return -ENOENT;
+ }
+
+ /*
+ * Can not count locking commands against total
+ * as they are allowed to block on server.
+ */
+
+ /* update # of requests on the wire to server */
+ if (timeout != CIFS_BLOCKING_OP) {
+ *credits -= 1;
+ server->in_flight++;
+ }
+ spin_unlock(&server->req_lock);
+ break;
+ }
+ }
+ return 0;
+}
+
+static int
+wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
+ const int optype)
+{
+ int *val;
+
+ val = server->ops->get_credits_field(server, optype);
+ /* Since an echo is already inflight, no need to wait to send another */
+ if (*val <= 0 && optype == CIFS_ECHO_OP)
+ return -EAGAIN;
+ return wait_for_free_credits(server, timeout, val);
+}
+
+int
+cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
+ unsigned int *num, unsigned int *credits)
+{
+ *num = size;
+ *credits = 0;
+ return 0;
+}
+
+static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
+ struct mid_q_entry **ppmidQ)
+{
+ if (ses->server->tcpStatus == CifsExiting) {
+ return -ENOENT;
+ }
+
+ if (ses->server->tcpStatus == CifsNeedReconnect) {
+ cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
+ return -EAGAIN;
+ }
+
+ if (ses->status == CifsNew) {
+ if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
+ (in_buf->Command != SMB_COM_NEGOTIATE))
+ return -EAGAIN;
+ /* else ok - we are setting up session */
+ }
+
+ if (ses->status == CifsExiting) {
+ /* check if SMB session is bad because we are setting it up */
+ if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
+ return -EAGAIN;
+ /* else ok - we are shutting down session */
+ }
+
+ *ppmidQ = AllocMidQEntry(in_buf, ses->server);
+ if (*ppmidQ == NULL)
+ return -ENOMEM;
+ spin_lock(&GlobalMid_Lock);
+ list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
+ spin_unlock(&GlobalMid_Lock);
+ return 0;
+}
+
+static int
+wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
+{
+ int error;
+
+ error = wait_event_freezekillable_unsafe(server->response_q,
+ midQ->mid_state != MID_REQUEST_SUBMITTED);
+ 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;
+
+ /* enable signing if server requires it */
+ if (server->sign)
+ hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
+
+ mid = AllocMidQEntry(hdr, server);
+ if (mid == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
+ if (rc) {
+ DeleteMidQEntry(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,
+ void *cbdata, const int flags)
+{
+ int rc, timeout, optype;
+ struct mid_q_entry *mid;
+ unsigned int credits = 0;
+
+ timeout = flags & CIFS_TIMEOUT_MASK;
+ optype = flags & CIFS_OP_MASK;
+
+ if ((flags & CIFS_HAS_CREDITS) == 0) {
+ rc = wait_for_free_request(server, timeout, optype);
+ if (rc)
+ return rc;
+ credits = 1;
+ }
+
+ mutex_lock(&server->srv_mutex);
+ mid = server->ops->setup_async_request(server, rqst);
+ if (IS_ERR(mid)) {
+ mutex_unlock(&server->srv_mutex);
+ add_credits_and_wake_if(server, credits, optype);
+ return PTR_ERR(mid);
+ }
+
+ mid->receive = receive;
+ mid->callback = callback;
+ mid->callback_data = cbdata;
+ mid->mid_state = MID_REQUEST_SUBMITTED;
+
+ /* put it on the pending_mid_q */
+ spin_lock(&GlobalMid_Lock);
+ list_add_tail(&mid->qhead, &server->pending_mid_q);
+ spin_unlock(&GlobalMid_Lock);
+
+
+ cifs_in_send_inc(server);
+ rc = smb_send_rqst(server, rqst);
+ cifs_in_send_dec(server);
+ cifs_save_when_sent(mid);
+
+ if (rc < 0)
+ server->sequence_number -= 2;
+ mutex_unlock(&server->srv_mutex);
+
+ if (rc == 0)
+ return 0;
+
+ cifs_delete_mid(mid);
+ 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];
+ int resp_buf_type;
+
+ iov[0].iov_base = in_buf;
+ iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
+ flags |= CIFS_NO_RESP;
+ rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
+ 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(&GlobalMid_Lock);
+ switch (mid->mid_state) {
+ case MID_RESPONSE_RECEIVED:
+ spin_unlock(&GlobalMid_Lock);
+ return rc;
+ case MID_RETRY_NEEDED:
+ rc = -EAGAIN;
+ break;
+ case MID_RESPONSE_MALFORMED:
+ rc = -EIO;
+ break;
+ case MID_SHUTDOWN:
+ rc = -EHOSTDOWN;
+ break;
+ default:
+ list_del_init(&mid->qhead);
+ cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
+ __func__, mid->mid, mid->mid_state);
+ rc = -EIO;
+ }
+ spin_unlock(&GlobalMid_Lock);
+
+ DeleteMidQEntry(mid);
+ return rc;
+}
+
+static inline int
+send_cancel(struct TCP_Server_Info *server, void *buf, struct mid_q_entry *mid)
+{
+ return server->ops->send_cancel ?
+ server->ops->send_cancel(server, buf, 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;
+ int rc = 0;
+ struct smb_rqst rqst = { .rq_iov = &iov,
+ .rq_nvec = 1 };
+
+ iov.iov_base = mid->resp_buf;
+ iov.iov_len = len;
+ /* FIXME: add code to kill session */
+ rc = cifs_verify_signature(&rqst, server,
+ mid->sequence_number);
+ if (rc)
+ cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
+ rc);
+ }
+
+ /* BB special case reconnect tid and uid here? */
+ return map_smb_to_linux_error(mid->resp_buf, log_error);
+}
+
+struct mid_q_entry *
+cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
+{
+ int rc;
+ struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
+ struct mid_q_entry *mid;
+
+ rc = allocate_mid(ses, hdr, &mid);
+ if (rc)
+ return ERR_PTR(rc);
+ rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
+ if (rc) {
+ cifs_delete_mid(mid);
+ return ERR_PTR(rc);
+ }
+ return mid;
+}
+
+int
+SendReceive2(const unsigned int xid, struct cifs_ses *ses,
+ struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
+ const int flags)
+{
+ int rc = 0;
+ int timeout, optype;
+ struct mid_q_entry *midQ;
+ char *buf = iov[0].iov_base;
+ unsigned int credits = 1;
+ struct smb_rqst rqst = { .rq_iov = iov,
+ .rq_nvec = n_vec };
+
+ timeout = flags & CIFS_TIMEOUT_MASK;
+ optype = flags & CIFS_OP_MASK;
+
+ *resp_buf_type = CIFS_NO_BUFFER; /* no response buf yet */
+
+ if ((ses == NULL) || (ses->server == NULL)) {
+ cifs_small_buf_release(buf);
+ cifs_dbg(VFS, "Null session\n");
+ return -EIO;
+ }
+
+ if (ses->server->tcpStatus == CifsExiting) {
+ cifs_small_buf_release(buf);
+ return -ENOENT;
+ }
+
+ /*
+ * 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.
+ */
+
+ rc = wait_for_free_request(ses->server, timeout, optype);
+ if (rc) {
+ cifs_small_buf_release(buf);
+ 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.
+ */
+
+ mutex_lock(&ses->server->srv_mutex);
+
+ midQ = ses->server->ops->setup_request(ses, &rqst);
+ if (IS_ERR(midQ)) {
+ mutex_unlock(&ses->server->srv_mutex);
+ cifs_small_buf_release(buf);
+ /* Update # of requests on wire to server */
+ add_credits(ses->server, 1, optype);
+ return PTR_ERR(midQ);
+ }
+
+ midQ->mid_state = MID_REQUEST_SUBMITTED;
+ cifs_in_send_inc(ses->server);
+ rc = smb_sendv(ses->server, iov, n_vec);
+ cifs_in_send_dec(ses->server);
+ cifs_save_when_sent(midQ);
+
+ if (rc < 0)
+ ses->server->sequence_number -= 2;
+ mutex_unlock(&ses->server->srv_mutex);
+
+ if (rc < 0) {
+ cifs_small_buf_release(buf);
+ goto out;
+ }
+
+ if (timeout == CIFS_ASYNC_OP) {
+ cifs_small_buf_release(buf);
+ goto out;
+ }
+
+ rc = wait_for_response(ses->server, midQ);
+ if (rc != 0) {
+ send_cancel(ses->server, buf, midQ);
+ spin_lock(&GlobalMid_Lock);
+ if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
+ midQ->callback = DeleteMidQEntry;
+ spin_unlock(&GlobalMid_Lock);
+ cifs_small_buf_release(buf);
+ add_credits(ses->server, 1, optype);
+ return rc;
+ }
+ spin_unlock(&GlobalMid_Lock);
+ }
+
+ cifs_small_buf_release(buf);
+
+ rc = cifs_sync_mid_result(midQ, ses->server);
+ if (rc != 0) {
+ add_credits(ses->server, 1, optype);
+ return rc;
+ }
+
+ if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
+ rc = -EIO;
+ cifs_dbg(FYI, "Bad MID state?\n");
+ goto out;
+ }
+
+ buf = (char *)midQ->resp_buf;
+ iov[0].iov_base = buf;
+ iov[0].iov_len = get_rfc1002_length(buf) + 4;
+ if (midQ->large_buf)
+ *resp_buf_type = CIFS_LARGE_BUFFER;
+ else
+ *resp_buf_type = CIFS_SMALL_BUFFER;
+
+ credits = ses->server->ops->get_credits(midQ);
+
+ rc = ses->server->ops->check_receive(midQ, ses->server,
+ flags & CIFS_LOG_ERROR);
+
+ /* mark it so buf will not be freed by cifs_delete_mid */
+ if ((flags & CIFS_NO_RESP) == 0)
+ midQ->resp_buf = NULL;
+out:
+ cifs_delete_mid(midQ);
+ add_credits(ses->server, credits, optype);
+
+ 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 timeout)
+{
+ int rc = 0;
+ struct mid_q_entry *midQ;
+
+ if (ses == NULL) {
+ cifs_dbg(VFS, "Null smb session\n");
+ return -EIO;
+ }
+ if (ses->server == NULL) {
+ cifs_dbg(VFS, "Null tcp session\n");
+ return -EIO;
+ }
+
+ if (ses->server->tcpStatus == CifsExiting)
+ return -ENOENT;
+
+ /* 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 (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
+ MAX_CIFS_HDR_SIZE - 4) {
+ cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
+ be32_to_cpu(in_buf->smb_buf_length));
+ return -EIO;
+ }
+
+ rc = wait_for_free_request(ses->server, timeout, 0);
+ 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 */
+
+ mutex_lock(&ses->server->srv_mutex);
+
+ rc = allocate_mid(ses, in_buf, &midQ);
+ if (rc) {
+ mutex_unlock(&ses->server->srv_mutex);
+ /* Update # of requests on wire to server */
+ add_credits(ses->server, 1, 0);
+ return rc;
+ }
+
+ rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
+ if (rc) {
+ mutex_unlock(&ses->server->srv_mutex);
+ goto out;
+ }
+
+ midQ->mid_state = MID_REQUEST_SUBMITTED;
+
+ cifs_in_send_inc(ses->server);
+ rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
+ cifs_in_send_dec(ses->server);
+ cifs_save_when_sent(midQ);
+
+ if (rc < 0)
+ ses->server->sequence_number -= 2;
+
+ mutex_unlock(&ses->server->srv_mutex);
+
+ if (rc < 0)
+ goto out;
+
+ if (timeout == CIFS_ASYNC_OP)
+ goto out;
+
+ rc = wait_for_response(ses->server, midQ);
+ if (rc != 0) {
+ send_cancel(ses->server, in_buf, midQ);
+ spin_lock(&GlobalMid_Lock);
+ if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
+ /* no longer considered to be "in-flight" */
+ midQ->callback = DeleteMidQEntry;
+ spin_unlock(&GlobalMid_Lock);
+ add_credits(ses->server, 1, 0);
+ return rc;
+ }
+ spin_unlock(&GlobalMid_Lock);
+ }
+
+ rc = cifs_sync_mid_result(midQ, ses->server);
+ if (rc != 0) {
+ add_credits(ses->server, 1, 0);
+ return rc;
+ }
+
+ if (!midQ->resp_buf || !out_buf ||
+ midQ->mid_state != MID_RESPONSE_RECEIVED) {
+ rc = -EIO;
+ cifs_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, ses->server, 0);
+out:
+ cifs_delete_mid(midQ);
+ add_credits(ses->server, 1, 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;
+
+ if (tcon == NULL || tcon->ses == NULL) {
+ cifs_dbg(VFS, "Null smb session\n");
+ return -EIO;
+ }
+ ses = tcon->ses;
+
+ if (ses->server == NULL) {
+ cifs_dbg(VFS, "Null tcp session\n");
+ return -EIO;
+ }
+
+ if (ses->server->tcpStatus == CifsExiting)
+ return -ENOENT;
+
+ /* 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 (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
+ MAX_CIFS_HDR_SIZE - 4) {
+ cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
+ be32_to_cpu(in_buf->smb_buf_length));
+ return -EIO;
+ }
+
+ rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
+ 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 */
+
+ mutex_lock(&ses->server->srv_mutex);
+
+ rc = allocate_mid(ses, in_buf, &midQ);
+ if (rc) {
+ mutex_unlock(&ses->server->srv_mutex);
+ return rc;
+ }
+
+ rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
+ if (rc) {
+ cifs_delete_mid(midQ);
+ mutex_unlock(&ses->server->srv_mutex);
+ return rc;
+ }
+
+ midQ->mid_state = MID_REQUEST_SUBMITTED;
+ cifs_in_send_inc(ses->server);
+ rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
+ cifs_in_send_dec(ses->server);
+ cifs_save_when_sent(midQ);
+
+ if (rc < 0)
+ ses->server->sequence_number -= 2;
+
+ mutex_unlock(&ses->server->srv_mutex);
+
+ if (rc < 0) {
+ cifs_delete_mid(midQ);
+ return rc;
+ }
+
+ /* Wait for a reply - allow signals to interrupt. */
+ rc = wait_event_interruptible(ses->server->response_q,
+ (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
+ ((ses->server->tcpStatus != CifsGood) &&
+ (ses->server->tcpStatus != CifsNew)));
+
+ /* Were we interrupted by a signal ? */
+ if ((rc == -ERESTARTSYS) &&
+ (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
+ ((ses->server->tcpStatus == CifsGood) ||
+ (ses->server->tcpStatus == CifsNew))) {
+
+ 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(ses->server, in_buf, midQ);
+ if (rc) {
+ cifs_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) {
+ cifs_delete_mid(midQ);
+ return rc;
+ }
+ }
+
+ rc = wait_for_response(ses->server, midQ);
+ if (rc) {
+ send_cancel(ses->server, in_buf, midQ);
+ spin_lock(&GlobalMid_Lock);
+ if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
+ /* no longer considered to be "in-flight" */
+ midQ->callback = DeleteMidQEntry;
+ spin_unlock(&GlobalMid_Lock);
+ return rc;
+ }
+ spin_unlock(&GlobalMid_Lock);
+ }
+
+ /* We got the response - restart system call. */
+ rstart = 1;
+ }
+
+ rc = cifs_sync_mid_result(midQ, ses->server);
+ if (rc != 0)
+ return rc;
+
+ /* rcvd frame is ok */
+ if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
+ rc = -EIO;
+ cifs_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, ses->server, 0);
+out:
+ cifs_delete_mid(midQ);
+ if (rstart && rc == -EACCES)
+ return -ERESTARTSYS;
+ return rc;
+}
Code Review / kvmfornfv.git / blobdiff