1 files changed, 243 insertions, 0 deletions
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
new file mode 100644
index 00000000000..6dec38f5522
--- /dev/null
+++ b/fs/cifs/smb1ops.c
@@ -0,0 +1,243 @@
+/*
+ *  SMB1 (CIFS) version specific operations
+ *
+ *  Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
+ *
+ *  This library is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License v2 as published
+ *  by the Free Software Foundation.
+ *
+ *  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 "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+#include "cifspdu.h"
+
+/*
+ * An NT cancel request header looks just like the original request except:
+ *
+ * The Command is SMB_COM_NT_CANCEL
+ * The WordCount is zeroed out
+ * The ByteCount is zeroed out
+ *
+ * This function mangles an existing request buffer into a
+ * SMB_COM_NT_CANCEL request and then sends it.
+ */
+static int
+send_nt_cancel(struct TCP_Server_Info *server, void *buf,
+	       struct mid_q_entry *mid)
+{
+	int rc = 0;
+	struct smb_hdr *in_buf = (struct smb_hdr *)buf;
+
+	/* -4 for RFC1001 length and +2 for BCC field */
+	in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4  + 2);
+	in_buf->Command = SMB_COM_NT_CANCEL;
+	in_buf->WordCount = 0;
+	put_bcc(0, in_buf);
+
+	mutex_lock(&server->srv_mutex);
+	rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
+	if (rc) {
+		mutex_unlock(&server->srv_mutex);
+		return rc;
+	}
+	rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
+	mutex_unlock(&server->srv_mutex);
+
+	cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
+		in_buf->Mid, rc);
+
+	return rc;
+}
+
+static bool
+cifs_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
+{
+	return ob1->netfid == ob2->netfid;
+}
+
+static unsigned int
+cifs_read_data_offset(char *buf)
+{
+	READ_RSP *rsp = (READ_RSP *)buf;
+	return le16_to_cpu(rsp->DataOffset);
+}
+
+static unsigned int
+cifs_read_data_length(char *buf)
+{
+	READ_RSP *rsp = (READ_RSP *)buf;
+	return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
+	       le16_to_cpu(rsp->DataLength);
+}
+
+static struct mid_q_entry *
+cifs_find_mid(struct TCP_Server_Info *server, char *buffer)
+{
+	struct smb_hdr *buf = (struct smb_hdr *)buffer;
+	struct mid_q_entry *mid;
+
+	spin_lock(&GlobalMid_Lock);
+	list_for_each_entry(mid, &server->pending_mid_q, qhead) {
+		if (mid->mid == buf->Mid &&
+		    mid->mid_state == MID_REQUEST_SUBMITTED &&
+		    le16_to_cpu(mid->command) == buf->Command) {
+			spin_unlock(&GlobalMid_Lock);
+			return mid;
+		}
+	}
+	spin_unlock(&GlobalMid_Lock);
+	return NULL;
+}
+
+static void
+cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add)
+{
+	spin_lock(&server->req_lock);
+	server->credits += add;
+	server->in_flight--;
+	spin_unlock(&server->req_lock);
+	wake_up(&server->request_q);
+}
+
+static void
+cifs_set_credits(struct TCP_Server_Info *server, const int val)
+{
+	spin_lock(&server->req_lock);
+	server->credits = val;
+	server->oplocks = val > 1 ? enable_oplocks : false;
+	spin_unlock(&server->req_lock);
+}
+
+static int *
+cifs_get_credits_field(struct TCP_Server_Info *server)
+{
+	return &server->credits;
+}
+
+/*
+ * Find a free multiplex id (SMB mid). Otherwise there could be
+ * mid collisions which might cause problems, demultiplexing the
+ * wrong response to this request. Multiplex ids could collide if
+ * one of a series requests takes much longer than the others, or
+ * if a very large number of long lived requests (byte range
+ * locks or FindNotify requests) are pending. No more than
+ * 64K-1 requests can be outstanding at one time. If no
+ * mids are available, return zero. A future optimization
+ * could make the combination of mids and uid the key we use
+ * to demultiplex on (rather than mid alone).
+ * In addition to the above check, the cifs demultiplex
+ * code already used the command code as a secondary
+ * check of the frame and if signing is negotiated the
+ * response would be discarded if the mid were the same
+ * but the signature was wrong. Since the mid is not put in the
+ * pending queue until later (when it is about to be dispatched)
+ * we do have to limit the number of outstanding requests
+ * to somewhat less than 64K-1 although it is hard to imagine
+ * so many threads being in the vfs at one time.
+ */
+static __u64
+cifs_get_next_mid(struct TCP_Server_Info *server)
+{
+	__u64 mid = 0;
+	__u16 last_mid, cur_mid;
+	bool collision;
+
+	spin_lock(&GlobalMid_Lock);
+
+	/* mid is 16 bit only for CIFS/SMB */
+	cur_mid = (__u16)((server->CurrentMid) & 0xffff);
+	/* we do not want to loop forever */
+	last_mid = cur_mid;
+	cur_mid++;
+
+	/*
+	 * This nested loop looks more expensive than it is.
+	 * In practice the list of pending requests is short,
+	 * fewer than 50, and the mids are likely to be unique
+	 * on the first pass through the loop unless some request
+	 * takes longer than the 64 thousand requests before it
+	 * (and it would also have to have been a request that
+	 * did not time out).
+	 */
+	while (cur_mid != last_mid) {
+		struct mid_q_entry *mid_entry;
+		unsigned int num_mids;
+
+		collision = false;
+		if (cur_mid == 0)
+			cur_mid++;
+
+		num_mids = 0;
+		list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {
+			++num_mids;
+			if (mid_entry->mid == cur_mid &&
+			    mid_entry->mid_state == MID_REQUEST_SUBMITTED) {
+				/* This mid is in use, try a different one */
+				collision = true;
+				break;
+			}
+		}
+
+		/*
+		 * if we have more than 32k mids in the list, then something
+		 * is very wrong. Possibly a local user is trying to DoS the
+		 * box by issuing long-running calls and SIGKILL'ing them. If
+		 * we get to 2^16 mids then we're in big trouble as this
+		 * function could loop forever.
+		 *
+		 * Go ahead and assign out the mid in this situation, but force
+		 * an eventual reconnect to clean out the pending_mid_q.
+		 */
+		if (num_mids > 32768)
+			server->tcpStatus = CifsNeedReconnect;
+
+		if (!collision) {
+			mid = (__u64)cur_mid;
+			server->CurrentMid = mid;
+			break;
+		}
+		cur_mid++;
+	}
+	spin_unlock(&GlobalMid_Lock);
+	return mid;
+}
+
+struct smb_version_operations smb1_operations = {
+	.send_cancel = send_nt_cancel,
+	.compare_fids = cifs_compare_fids,
+	.setup_request = cifs_setup_request,
+	.check_receive = cifs_check_receive,
+	.add_credits = cifs_add_credits,
+	.set_credits = cifs_set_credits,
+	.get_credits_field = cifs_get_credits_field,
+	.get_next_mid = cifs_get_next_mid,
+	.read_data_offset = cifs_read_data_offset,
+	.read_data_length = cifs_read_data_length,
+	.map_error = map_smb_to_linux_error,
+	.find_mid = cifs_find_mid,
+	.check_message = checkSMB,
+	.dump_detail = cifs_dump_detail,
+	.is_oplock_break = is_valid_oplock_break,
+};
+
+struct smb_version_values smb1_values = {
+	.version_string = SMB1_VERSION_STRING,
+	.large_lock_type = LOCKING_ANDX_LARGE_FILES,
+	.exclusive_lock_type = 0,
+	.shared_lock_type = LOCKING_ANDX_SHARED_LOCK,
+	.unlock_lock_type = 0,
+	.header_size = sizeof(struct smb_hdr),
+	.max_header_size = MAX_CIFS_HDR_SIZE,
+	.read_rsp_size = sizeof(READ_RSP),
+};