source4/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 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         TALLOC_CTX *mem_ctx;
  48
  49         if (!tdbd) {
  50                 mem_ctx = talloc_init("receive_unexpected");
  51                 if (!mem_ctx) return;
  52                 tdbd = tdb_open_log(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                         DEBUG(0,("Failed to open unexpected.tdb\n"));
  58                         return;
  59                 }
  60         }
  61
  62         memset(buf,'\0',sizeof(buf));
  63
  64         len = build_packet(buf, p);
  65
  66         key.packet_type = p->packet_type;
  67         key.timestamp = p->timestamp;
  68         key.count = count++;
  69
  70         kbuf.dptr = (char *)&key;
  71         kbuf.dsize = sizeof(key);
  72         dbuf.dptr = 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 static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
  85 {
  86         struct unexpected_key key;
  87
  88         memcpy(&key, kbuf.dptr, sizeof(key));
  89
  90         if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
  91                 tdb_delete(ttdb, kbuf);
  92         }
  93
  94         return 0;
  95 }
  96
  97
  98 /****************************************************************************
  99 delete all old unexpected packets
 100   **************************************************************************/
 101 void clear_unexpected(time_t t)
 102 {
 103         if (!tdbd) return;
 104
 105         if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
 106                 return;
 107
 108         lastt = t;
 109
 110         tdb_traverse(tdbd, traverse_fn, NULL);
 111 }
 112
 113
 114 static struct packet_struct *matched_packet;
 115 static int match_id;
 116 static enum packet_type match_type;
 117 static const char *match_name;
 118
 119 /****************************************************************************
 120 tdb traversal fn to find a matching 137 packet
 121   **************************************************************************/
 122 static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
 123 {
 124         struct unexpected_key key;
 125         struct packet_struct *p;
 126
 127         memcpy(&key, kbuf.dptr, sizeof(key));
 128
 129         if (key.packet_type != match_type) return 0;
 130
 131         p = parse_packet(dbuf.dptr, dbuf.dsize, match_type);
 132
 133         if ((match_type == NMB_PACKET &&
 134              p->packet.nmb.header.name_trn_id == match_id) ||
 135             (match_type == DGRAM_PACKET &&
 136              match_mailslot_name(p, match_name))) {
 137                 matched_packet = p;
 138                 return -1;
 139         }
 140
 141         free_packet(p);
 142
 143         return 0;
 144 }
 145
 146
 147 /****************************************************************************
 148 check for a particular packet in the unexpected packet queue
 149   **************************************************************************/
 150 struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
 151                                          const char *mailslot_name)
 152 {
 153         TDB_CONTEXT *tdb2;
 154         TALLOC_CTX *mem_ctx;
 155
 156         mem_ctx = talloc_init("receive_unexpected");
 157         if (!mem_ctx) return NULL;
 158         tdb2 = tdb_open_log(lock_path(mem_ctx, "unexpected.tdb"), 0, 0, O_RDONLY, 0);
 159         talloc_destroy(mem_ctx);
 160         if (!tdb2) return NULL;
 161
 162         matched_packet = NULL;
 163         match_id = id;
 164         match_type = packet_type;
 165         match_name = mailslot_name;
 166
 167         tdb_traverse(tdb2, traverse_match, NULL);
 168
 169         tdb_close(tdb2);
 170
 171         return matched_packet;
 172 }