source/libsmb/unexpected.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    handle unexpected packets
   4    Copyright (C) Andrew Tridgell 2000
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20 */
  21
  22 #include "includes.h"
  23
  24 static TDB_CONTEXT *tdbd = NULL;
  25
  26 /* the key type used in the unexpeceted packet database */
  27 struct unexpected_key {
  28         enum packet_type packet_type;
  29         time_t timestamp;
  30         int count;
  31 };
  32
  33
  34
  35 /****************************************************************************
  36  all unexpected packets are passed in here, to be stored in a unexpected
  37  packet database. This allows nmblookup and other tools to receive packets
  38  erroneoously sent to the wrong port by broken MS systems
  39   **************************************************************************/
  40 void unexpected_packet(struct packet_struct *p)
  41 {
  42         static int count;
  43         TDB_DATA kbuf, dbuf;
  44         struct unexpected_key key;
  45         char buf[1024];
  46         int len=0;
  47
  48         if (!tdbd) {
  49                 tdbd = tdb_open_log(lock_path("unexpected.tdb"), 0,
  50                                TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
  51                                O_RDWR | O_CREAT, 0644);
  52                 if (!tdbd) {
  53                         DEBUG(0,("Failed to open unexpected.tdb\n"));
  54                         return;
  55                 }
  56         }
  57
  58         memset(buf,'\0',sizeof(buf));
  59
  60         len = build_packet(buf, p);
  61
  62         key.packet_type = p->packet_type;
  63         key.timestamp = p->timestamp;
  64         key.count = count++;
  65
  66         kbuf.dptr = (char *)&key;
  67         kbuf.dsize = sizeof(key);
  68         dbuf.dptr = buf;
  69         dbuf.dsize = len;
  70
  71         tdb_store(tdbd, kbuf, dbuf, TDB_REPLACE);
  72 }
  73
  74
  75 static time_t lastt;
  76
  77 /****************************************************************************
  78 delete the record if it is too old
  79   **************************************************************************/
  80 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
  81 {
  82         struct unexpected_key key;
  83
  84         memcpy(&key, kbuf.dptr, sizeof(key));
  85
  86         if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
  87                 tdb_delete(ttdb, kbuf);
  88         }
  89
  90         return 0;
  91 }
  92
  93
  94 /****************************************************************************
  95 delete all old unexpected packets
  96   **************************************************************************/
  97 void clear_unexpected(time_t t)
  98 {
  99         if (!tdbd) return;
 100
 101         if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
 102                 return;
 103
 104         lastt = t;
 105
 106         tdb_traverse(tdbd, traverse_fn, NULL);
 107 }
 108
 109
 110 static struct packet_struct *matched_packet;
 111 static int match_id;
 112 static enum packet_type match_type;
 113 static const char *match_name;
 114
 115 /****************************************************************************
 116 tdb traversal fn to find a matching 137 packet
 117   **************************************************************************/
 118 static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 119 {
 120         struct unexpected_key key;
 121         struct packet_struct *p;
 122
 123         memcpy(&key, kbuf.dptr, sizeof(key));
 124
 125         if (key.packet_type != match_type) return 0;
 126
 127         p = parse_packet(dbuf.dptr, dbuf.dsize, match_type);
 128
 129         if ((match_type == NMB_PACKET &&
 130              p->packet.nmb.header.name_trn_id == match_id) ||
 131             (match_type == DGRAM_PACKET &&
 132              match_mailslot_name(p, match_name))) {
 133                 matched_packet = p;
 134                 return -1;
 135         }
 136
 137         free_packet(p);
 138
 139         return 0;
 140 }
 141
 142
 143 /****************************************************************************
 144 check for a particular packet in the unexpected packet queue
 145   **************************************************************************/
 146 struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
 147                                          const char *mailslot_name)
 148 {
 149         TDB_CONTEXT *tdb2;
 150
 151         tdb2 = tdb_open_log(lock_path("unexpected.tdb"), 0, 0, O_RDONLY, 0);
 152         if (!tdb2) return NULL;
 153
 154         matched_packet = NULL;
 155         match_id = id;
 156         match_type = packet_type;
 157         match_name = mailslot_name;
 158
 159         tdb_traverse(tdb2, traverse_match, NULL);
 160
 161         tdb_close(tdb2);
 162
 163         return matched_packet;
 164 }