source/libcli/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 struct tdb_wrap *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         TALLOC_CTX *mem_ctx;
  48
  49         if (!tdbd) {
  50                 mem_ctx = talloc_init("receive_unexpected");
  51                 if (!mem_ctx) return;
  52                 tdbd = tdb_wrap_open(NULL, lock_path(mem_ctx, "unexpected.tdb"), 0,
  53                                      TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
  54                                      O_RDWR | O_CREAT, 0644);
  55                 talloc_destroy(mem_ctx);
  56                 if (!tdbd) {
  57                         return;
  58                 }
  59         }
  60
  61         memset(buf,'\0',sizeof(buf));
  62
  63         len = build_packet(buf, p);
  64
  65         key.packet_type = p->packet_type;
  66         key.timestamp = p->timestamp;
  67         key.count = count++;
  68
  69         kbuf.dptr = (char *)&key;
  70         kbuf.dsize = sizeof(key);
  71         dbuf.dptr = buf;
  72         dbuf.dsize = len;
  73
  74         tdb_store(tdbd->tdb, kbuf, dbuf, TDB_REPLACE);
  75 }
  76
  77
  78 static time_t lastt;
  79
  80 /****************************************************************************
  81 delete the record if it is too old
  82   **************************************************************************/
  83 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
  84 {
  85         struct unexpected_key key;
  86
  87         memcpy(&key, kbuf.dptr, sizeof(key));
  88
  89         if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
  90                 tdb_delete(ttdb, kbuf);
  91         }
  92
  93         return 0;
  94 }
  95
  96
  97 /****************************************************************************
  98 delete all old unexpected packets
  99   **************************************************************************/
 100 void clear_unexpected(time_t t)
 101 {
 102         if (!tdbd) return;
 103
 104         if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
 105                 return;
 106
 107         lastt = t;
 108
 109         tdb_traverse(tdbd->tdb, traverse_fn, NULL);
 110 }
 111
 112
 113 static struct packet_struct *matched_packet;
 114 static int match_id;
 115 static enum packet_type match_type;
 116 static const char *match_name;
 117
 118 /****************************************************************************
 119 tdb traversal fn to find a matching 137 packet
 120   **************************************************************************/
 121 static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 122 {
 123         struct unexpected_key key;
 124         struct packet_struct *p;
 125
 126         memcpy(&key, kbuf.dptr, sizeof(key));
 127
 128         if (key.packet_type != match_type) return 0;
 129
 130         p = parse_packet(dbuf.dptr, dbuf.dsize, match_type);
 131
 132         if ((match_type == NMB_PACKET &&
 133              p->packet.nmb.header.name_trn_id == match_id) ||
 134             (match_type == DGRAM_PACKET &&
 135              match_mailslot_name(p, match_name))) {
 136                 matched_packet = p;
 137                 return -1;
 138         }
 139
 140         free_packet(p);
 141
 142         return 0;
 143 }
 144
 145
 146 /****************************************************************************
 147 check for a particular packet in the unexpected packet queue
 148   **************************************************************************/
 149 struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
 150                                          const char *mailslot_name)
 151 {
 152         struct tdb_wrap *tdb2;
 153         TALLOC_CTX *mem_ctx;
 154
 155         mem_ctx = talloc_init("receive_unexpected");
 156         if (!mem_ctx) return NULL;
 157         tdb2 = tdb_wrap_open(mem_ctx, lock_path(mem_ctx, "unexpected.tdb"), 0, 0, O_RDONLY, 0);
 158         if (!tdb2) {
 159                 talloc_destroy(mem_ctx);
 160                 return NULL;
 161         }
 162
 163         matched_packet = NULL;
 164         match_id = id;
 165         match_type = packet_type;
 166         match_name = mailslot_name;
 167
 168         tdb_traverse(tdb2->tdb, traverse_match, NULL);
 169
 170         talloc_destroy(mem_ctx);
 171
 172         return matched_packet;
 173 }