Pileus Git - ~andy/linux/blob - fs/cifs/smb1ops.c

   1 /*
   2  *  SMB1 (CIFS) version specific operations
   3  *
   4  *  Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License v2 as published
   8  *  by the Free Software Foundation.
   9  *
  10  *  This library is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  *  the GNU Lesser General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU Lesser General Public License
  16  *  along with this library; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  */
  19
  20 #include "cifsglob.h"
  21 #include "cifsproto.h"
  22 #include "cifs_debug.h"
  23 #include "cifspdu.h"
  24
  25 /*
  26  * An NT cancel request header looks just like the original request except:
  27  *
  28  * The Command is SMB_COM_NT_CANCEL
  29  * The WordCount is zeroed out
  30  * The ByteCount is zeroed out
  31  *
  32  * This function mangles an existing request buffer into a
  33  * SMB_COM_NT_CANCEL request and then sends it.
  34  */
  35 static int
  36 send_nt_cancel(struct TCP_Server_Info *server, void *buf,
  37                struct mid_q_entry *mid)
  38 {
  39         int rc = 0;
  40         struct smb_hdr *in_buf = (struct smb_hdr *)buf;
  41
  42         /* -4 for RFC1001 length and +2 for BCC field */
  43         in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4  + 2);
  44         in_buf->Command = SMB_COM_NT_CANCEL;
  45         in_buf->WordCount = 0;
  46         put_bcc(0, in_buf);
  47
  48         mutex_lock(&server->srv_mutex);
  49         rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
  50         if (rc) {
  51                 mutex_unlock(&server->srv_mutex);
  52                 return rc;
  53         }
  54         rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
  55         mutex_unlock(&server->srv_mutex);
  56
  57         cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
  58                 in_buf->Mid, rc);
  59
  60         return rc;
  61 }
  62
  63 static bool
  64 cifs_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
  65 {
  66         return ob1->netfid == ob2->netfid;
  67 }
  68
  69 static unsigned int
  70 cifs_read_data_offset(char *buf)
  71 {
  72         READ_RSP *rsp = (READ_RSP *)buf;
  73         return le16_to_cpu(rsp->DataOffset);
  74 }
  75
  76 static unsigned int
  77 cifs_read_data_length(char *buf)
  78 {
  79         READ_RSP *rsp = (READ_RSP *)buf;
  80         return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
  81                le16_to_cpu(rsp->DataLength);
  82 }
  83
  84 static struct mid_q_entry *
  85 cifs_find_mid(struct TCP_Server_Info *server, char *buffer)
  86 {
  87         struct smb_hdr *buf = (struct smb_hdr *)buffer;
  88         struct mid_q_entry *mid;
  89
  90         spin_lock(&GlobalMid_Lock);
  91         list_for_each_entry(mid, &server->pending_mid_q, qhead) {
  92                 if (mid->mid == buf->Mid &&
  93                     mid->mid_state == MID_REQUEST_SUBMITTED &&
  94                     le16_to_cpu(mid->command) == buf->Command) {
  95                         spin_unlock(&GlobalMid_Lock);
  96                         return mid;
  97                 }
  98         }
  99         spin_unlock(&GlobalMid_Lock);
 100         return NULL;
 101 }
 102
 103 static void
 104 cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add)
 105 {
 106         spin_lock(&server->req_lock);
 107         server->credits += add;
 108         server->in_flight--;
 109         spin_unlock(&server->req_lock);
 110         wake_up(&server->request_q);
 111 }
 112
 113 static void
 114 cifs_set_credits(struct TCP_Server_Info *server, const int val)
 115 {
 116         spin_lock(&server->req_lock);
 117         server->credits = val;
 118         server->oplocks = val > 1 ? enable_oplocks : false;
 119         spin_unlock(&server->req_lock);
 120 }
 121
 122 static int *
 123 cifs_get_credits_field(struct TCP_Server_Info *server)
 124 {
 125         return &server->credits;
 126 }
 127
 128 struct smb_version_operations smb1_operations = {
 129         .send_cancel = send_nt_cancel,
 130         .compare_fids = cifs_compare_fids,
 131         .setup_request = cifs_setup_request,
 132         .check_receive = cifs_check_receive,
 133         .add_credits = cifs_add_credits,
 134         .set_credits = cifs_set_credits,
 135         .get_credits_field = cifs_get_credits_field,
 136         .read_data_offset = cifs_read_data_offset,
 137         .read_data_length = cifs_read_data_length,
 138         .map_error = map_smb_to_linux_error,
 139         .find_mid = cifs_find_mid,
 140         .check_message = checkSMB,
 141         .dump_detail = cifs_dump_detail,
 142         .is_oplock_break = is_valid_oplock_break,
 143 };
 144
 145 struct smb_version_values smb1_values = {
 146         .version_string = SMB1_VERSION_STRING,
 147         .large_lock_type = LOCKING_ANDX_LARGE_FILES,
 148         .exclusive_lock_type = 0,
 149         .shared_lock_type = LOCKING_ANDX_SHARED_LOCK,
 150         .unlock_lock_type = 0,
 151         .header_size = sizeof(struct smb_hdr),
 152         .max_header_size = MAX_CIFS_HDR_SIZE,
 153         .read_rsp_size = sizeof(READ_RSP),
 154 };