Commit message: cifs: move check for NULL socket into smb_send_rqst

Cai reported this oops:

[90701.616664] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
[90701.625438] IP: [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.632167] PGD fea319067 PUD 103fda4067 PMD 0
[90701.637255] Oops: 0000 [#1] SMP
[90701.640878] Modules linked in: des_generic md4 nls_utf8 cifs dns_resolver binfmt_misc tun sg igb iTCO_wdt iTCO_vendor_support lpc_ich pcspkr i2c_i801 i2c_core i7core_edac edac_core ioatdma dca mfd_core coretemp kvm_intel kvm crc32c_intel microcode sr_mod cdrom ata_generic sd_mod pata_acpi crc_t10dif ata_piix libata megaraid_sas dm_mirror dm_region_hash dm_log dm_mod
[90701.677655] CPU 10
[90701.679808] Pid: 9627, comm: ls Tainted: G        W    3.7.1+ #10 QCI QSSC-S4R/QSSC-S4R
[90701.688950] RIP: 0010:[<ffffffff814a343e>]  [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.698383] RSP: 0018:ffff88177b431bb8  EFLAGS: 00010206
[90701.704309] RAX: ffff88177b431fd8 RBX: 00007ffffffff000 RCX: ffff88177b431bec
[90701.712271] RDX: 0000000000000003 RSI: 0000000000000006 RDI: 0000000000000000
[90701.720223] RBP: ffff88177b431bc8 R08: 0000000000000004 R09: 0000000000000000
[90701.728185] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
[90701.736147] R13: ffff88184ef92000 R14: 0000000000000023 R15: ffff88177b431c88
[90701.744109] FS:  00007fd56a1a47c0(0000) GS:ffff88105fc40000(0000) knlGS:0000000000000000
[90701.753137] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[90701.759550] CR2: 0000000000000028 CR3: 000000104f15f000 CR4: 00000000000007e0
[90701.767512] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[90701.775465] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[90701.783428] Process ls (pid: 9627, threadinfo ffff88177b430000, task ffff88185ca4cb60)
[90701.792261] Stack:
[90701.794505]  0000000000000023 ffff88177b431c50 ffff88177b431c38 ffffffffa014fcb1
[90701.802809]  ffff88184ef921bc 0000000000000000 00000001ffffffff ffff88184ef921c0
[90701.811123]  ffff88177b431c08 ffffffff815ca3d9 ffff88177b431c18 ffff880857758000
[90701.819433] Call Trace:
[90701.822183]  [<ffffffffa014fcb1>] smb_send_rqst+0x71/0x1f0 [cifs]
[90701.828991]  [<ffffffff815ca3d9>] ? schedule+0x29/0x70
[90701.834736]  [<ffffffffa014fe6d>] smb_sendv+0x3d/0x40 [cifs]
[90701.841062]  [<ffffffffa014fe96>] smb_send+0x26/0x30 [cifs]
[90701.847291]  [<ffffffffa015801f>] send_nt_cancel+0x6f/0xd0 [cifs]
[90701.854102]  [<ffffffffa015075e>] SendReceive+0x18e/0x360 [cifs]
[90701.860814]  [<ffffffffa0134a78>] CIFSFindFirst+0x1a8/0x3f0 [cifs]
[90701.867724]  [<ffffffffa013f731>] ? build_path_from_dentry+0xf1/0x260 [cifs]
[90701.875601]  [<ffffffffa013f731>] ? build_path_from_dentry+0xf1/0x260 [cifs]
[90701.883477]  [<ffffffffa01578e6>] cifs_query_dir_first+0x26/0x30 [cifs]
[90701.890869]  [<ffffffffa015480d>] initiate_cifs_search+0xed/0x250 [cifs]
[90701.898354]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.904486]  [<ffffffffa01554cb>] cifs_readdir+0x45b/0x8f0 [cifs]
[90701.911288]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.917410]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.923533]  [<ffffffff81195970>] ? fillonedir+0x100/0x100
[90701.929657]  [<ffffffff81195848>] vfs_readdir+0xb8/0xe0
[90701.935490]  [<ffffffff81195b9f>] sys_getdents+0x8f/0x110
[90701.941521]  [<ffffffff815d3b99>] system_call_fastpath+0x16/0x1b
[90701.948222] Code: 66 90 55 65 48 8b 04 25 f0 c6 00 00 48 89 e5 53 48 83 ec 08 83 fe 01 48 8b 98 48 e0 ff ff 48 c7 80 48 e0 ff ff ff ff ff ff 74 22 <48> 8b 47 28 ff 50 68 65 48 8b 14 25 f0 c6 00 00 48 89 9a 48 e0
[90701.970313] RIP  [<ffffffff814a343e>] kernel_setsockopt+0x2e/0x60
[90701.977125]  RSP <ffff88177b431bb8>
[90701.981018] CR2: 0000000000000028
[90701.984809] ---[ end trace 24bd602971110a43 ]---

This is likely due to a race vs. a reconnection event.

The current code checks for a NULL socket in smb_send_kvec, but that's
too late. By the time that check is done, the socket will already have
been passed to kernel_setsockopt. Move the check into smb_send_rqst, so
that it's checked earlier.

In truth, this is a bit of a half-assed fix. The -ENOTSOCK error
return here looks like it could bubble back up to userspace. The locking
rules around the ssocket pointer are really unclear as well. There are
cases where the ssocket pointer is changed without holding the srv_mutex,
but I'm not clear whether there's a potential race here yet or not.

This code seems like it could benefit from some fundamental re-think of
how the socket handling should behave. Until then though, this patch
should at least fix the above oops in most cases.

Cc: <stable@vger.kernel.org> # 3.7+
Reported-and-Tested-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CVE: CVE-2013-3302
CWE: CWE-362
Vulnerability description: Race condition in the smb_send_rqst function in fs/cifs/transport.c in the Linux kernel before 3.7.2 allows local users to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact via vectors involving a reconnection event.

Project: linux
File: transport.c

AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
{
	struct mid_q_entry *temp;

	if (server == NULL) {
		cERROR(1, "Null TCP session in AllocMidQEntry");
		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 = smb_buffer->Mid;	/* always LE */
		temp->pid = current->pid;
		temp->command = cpu_to_le16(smb_buffer->Command);
		cFYI(1, "For smb_command %d", 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;
}

Project: linux
File: transport.c

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)) {
			printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %llu",
			       midEntry->command, midEntry->mid);
			printk(" 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);
}

Project: linux
File: transport.c

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) {
		cERROR(1, "Null smb session");
		return -EIO;
	}
	if (ses->server == NULL) {
		cERROR(1, "Null tcp session");
		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) {
		cERROR(1, "Illegal length, greater than maximum frame, %d",
			   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);
	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;
		cERROR(1, "Bad MID state?");
		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;
}

Project: linux
File: transport.c

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);
		cERROR(1, "Null session");
		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);

	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;
		cFYI(1, "Bad MID state?");
		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;
}

Project: linux
File: transport.c

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) {
		cERROR(1, "Null smb session");
		return -EIO;
	}
	ses = tcon->ses;

	if (ses->server == NULL) {
		cERROR(1, "Null tcp session");
		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) {
		cERROR(1, "Illegal length, greater than maximum frame, %d",
			   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);
	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;
		cERROR(1, "Bad MID state?");
		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;
}

Project: linux
File: transport.c

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);
	cFYI(DBG2, "SendRcvNoRsp flags %d rc %d", flags, rc);

	return rc;
}

Project: linux
File: transport.c

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) {
		cFYI(1, "tcp session dead - return to caller to retry");
		return -EAGAIN;
	}

	if (ses->status != CifsGood) {
		/* check if SMB session is bad because we are setting it up */
		if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
			(in_buf->Command != SMB_COM_NEGOTIATE))
			return -EAGAIN;
		/* else ok - we are setting up 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;
}

Project: linux
File: transport.c

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;

	timeout = flags & CIFS_TIMEOUT_MASK;
	optype = flags & CIFS_OP_MASK;

	rc = wait_for_free_request(server, timeout, optype);
	if (rc)
		return rc;

	mutex_lock(&server->srv_mutex);
	mid = server->ops->setup_async_request(server, rqst);
	if (IS_ERR(mid)) {
		mutex_unlock(&server->srv_mutex);
		add_credits(server, 1, optype);
		wake_up(&server->request_q);
		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);
	mutex_unlock(&server->srv_mutex);

	if (rc == 0)
		return 0;

	cifs_delete_mid(mid);
	add_credits(server, 1, optype);
	wake_up(&server->request_q);
	return rc;
}

Project: linux
File: transport.c

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->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
		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 + 1);
		if (rc)
			cERROR(1, "SMB signature verification returned error = "
			       "%d", rc);
	}

	/* BB special case reconnect tid and uid here? */
	return map_smb_to_linux_error(mid->resp_buf, log_error);
}

Project: linux
File: transport.c

cifs_delete_mid(struct mid_q_entry *mid)
{
	spin_lock(&GlobalMid_Lock);
	list_del(&mid->qhead);
	spin_unlock(&GlobalMid_Lock);

	DeleteMidQEntry(mid);
}

Project: linux
File: transport.c

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;
}

Project: linux
File: transport.c

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->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
		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;
}

Project: linux
File: transport.c

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;
}

Project: linux
File: transport.c

cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
{
	int rc = 0;

	cFYI(1, "%s: cmd=%d mid=%llu state=%d", __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);
		cERROR(1, "%s: invalid mid state mid=%llu state=%d", __func__,
		       mid->mid, mid->mid_state);
		rc = -EIO;
	}
	spin_unlock(&GlobalMid_Lock);

	DeleteMidQEntry(mid);
	return rc;
}

Project: linux
File: transport.c

cifs_wake_up_task(struct mid_q_entry *mid)
{
	wake_up_process(mid->callback_data);
}

Project: linux
File: transport.c

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;
}

Project: linux
File: transport.c

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);
}

Project: linux
File: transport.c

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);
}

Project: linux
File: transport.c

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;
}

Project: linux
File: transport.c

wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
		      const int optype)
{
	return wait_for_free_credits(server, timeout,
				server->ops->get_credits_field(server, optype));
}

Project: linux
File: transport.c

wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
{
	int error;

	error = wait_event_freezekillable(server->response_q,
				    midQ->mid_state != MID_REQUEST_SUBMITTED);
	if (error < 0)
		return -ERESTARTSYS;

	return 0;
}