source3/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 3 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, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 #include "includes.h"
  22
  23 static TDB_CONTEXT *tdbd = NULL;
  24
  25 /* the key type used in the unexpeceted packet database */
  26 struct unexpected_key {
  27         enum packet_type packet_type;
  28         time_t timestamp;
  29         int count;
  30 };
  31
  32 /****************************************************************************
  33  All unexpected packets are passed in here, to be stored in a unexpected
  34  packet database. This allows nmblookup and other tools to receive packets
  35  erroneoously sent to the wrong port by broken MS systems.
  36 **************************************************************************/
  37
  38 void unexpected_packet(struct packet_struct *p)
  39 {
  40         static int count;
  41         TDB_DATA kbuf, dbuf;
  42         struct unexpected_key key;
  43         char buf[1024];
  44         int len=0;
  45         uint32_t enc_ip;
  46
  47         if (!tdbd) {
  48                 tdbd = tdb_open_log(lock_path("unexpected.tdb"), 0,
  49                                TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
  50                                O_RDWR | O_CREAT, 0644);
  51                 if (!tdbd) {
  52                         DEBUG(0,("Failed to open unexpected.tdb\n"));
  53                         return;
  54                 }
  55         }
  56
  57         memset(buf,'\0',sizeof(buf));
  58
  59         /* Encode the ip addr and port. */
  60         enc_ip = ntohl(p->ip.s_addr);
  61         SIVAL(buf,0,enc_ip);
  62         SSVAL(buf,4,p->port);
  63
  64         len = build_packet(&buf[6], sizeof(buf)-6, p) + 6;
  65
  66         key.packet_type = p->packet_type;
  67         key.timestamp = p->timestamp;
  68         key.count = count++;
  69
  70         kbuf.dptr = (uint8_t *)&key;
  71         kbuf.dsize = sizeof(key);
  72         dbuf.dptr = (uint8_t *)buf;
  73         dbuf.dsize = len;
  74
  75         tdb_store(tdbd, kbuf, dbuf, TDB_REPLACE);
  76 }
  77
  78
  79 static time_t lastt;
  80
  81 /****************************************************************************
  82  Delete the record if it is too old.
  83 **************************************************************************/
  84
  85 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
  86 {
  87         struct unexpected_key key;
  88
  89         memcpy(&key, kbuf.dptr, sizeof(key));
  90
  91         if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
  92                 tdb_delete(ttdb, kbuf);
  93         }
  94
  95         return 0;
  96 }
  97
  98
  99 /****************************************************************************
 100  Delete all old unexpected packets.
 101 **************************************************************************/
 102
 103 void clear_unexpected(time_t t)
 104 {
 105         if (!tdbd) return;
 106
 107         if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
 108                 return;
 109
 110         lastt = t;
 111
 112         tdb_traverse(tdbd, traverse_fn, NULL);
 113 }
 114
 115
 116 static struct packet_struct *matched_packet;
 117 static int match_id;
 118 static enum packet_type match_type;
 119 static const char *match_name;
 120
 121 /****************************************************************************
 122  tdb traversal fn to find a matching 137 packet.
 123 **************************************************************************/
 124
 125 static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 126 {
 127         struct unexpected_key key;
 128         struct in_addr ip;
 129         uint32_t enc_ip;
 130         int port;
 131         struct packet_struct *p;
 132
 133         memcpy(&key, kbuf.dptr, sizeof(key));
 134
 135         if (key.packet_type != match_type) return 0;
 136
 137         if (dbuf.dsize < 6) {
 138                 return 0;
 139         }
 140
 141         /* Decode the ip addr and port. */
 142         enc_ip = IVAL(dbuf.dptr,0);
 143         ip.s_addr = htonl(enc_ip);
 144         port = SVAL(dbuf.dptr,4);
 145
 146         p = parse_packet((char *)&dbuf.dptr[6],
 147                         dbuf.dsize-6,
 148                         match_type,
 149                         ip,
 150                         port);
 151
 152         if ((match_type == NMB_PACKET &&
 153              p->packet.nmb.header.name_trn_id == match_id) ||
 154             (match_type == DGRAM_PACKET &&
 155              match_mailslot_name(p, match_name))) {
 156                 matched_packet = p;
 157                 return -1;
 158         }
 159
 160         free_packet(p);
 161
 162         return 0;
 163 }
 164
 165 /****************************************************************************
 166  Check for a particular packet in the unexpected packet queue.
 167 **************************************************************************/
 168
 169 struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
 170                                          const char *mailslot_name)
 171 {
 172         TDB_CONTEXT *tdb2;
 173
 174         tdb2 = tdb_open_log(lock_path("unexpected.tdb"), 0, 0, O_RDONLY, 0);
 175         if (!tdb2) return NULL;
 176
 177         matched_packet = NULL;
 178         match_id = id;
 179         match_type = packet_type;
 180         match_name = mailslot_name;
 181
 182         tdb_traverse(tdb2, traverse_match, NULL);
 183
 184         tdb_close(tdb2);
 185
 186         return matched_packet;
 187 }