packet-lpd.c

   1 /* packet-lpd.c
   2  * Routines for LPR and LPRng packet disassembly
   3  * Gilbert Ramirez <gram@alumni.rice.edu>
   4  *
   5  * $Id: packet-lpd.c,v 1.35 2002/01/24 09:20:49 guy Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #ifdef HAVE_SYS_TYPES_H
  31 # include <sys/types.h>
  32 #endif
  33
  34 #include <string.h>
  35
  36 #include <glib.h>
  37 #include <epan/packet.h>
  38
  39 #define TCP_PORT_PRINTER                515
  40
  41 static int proto_lpd = -1;
  42 static int hf_lpd_response = -1;
  43 static int hf_lpd_request = -1;
  44
  45 static gint ett_lpd = -1;
  46
  47 enum lpr_type { request, response, unknown };
  48
  49 static gint find_printer_string(tvbuff_t *tvb, int offset);
  50
  51 static dissector_handle_t data_handle;
  52
  53 static void
  54 dissect_lpd(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  55 {
  56         proto_tree      *lpd_tree;
  57         proto_item      *ti;
  58         enum lpr_type   lpr_packet_type;
  59         guint8          code;
  60         gint            printer_len;
  61
  62         /* This information comes from the LPRng HOWTO, which also describes
  63                 RFC 1179. http://www.astart.com/lprng/LPRng-HOWTO.html */
  64         static char     *lpd_client_code[] = {
  65                 "Unknown command",
  66                 "LPC: start print / jobcmd: abort",
  67                 "LPR: transfer a printer job / jobcmd: receive control file",
  68                 "LPQ: print short form of queue status / jobcmd: receive data file",
  69                 "LPQ: print long form of queue status",
  70                 "LPRM: remove jobs",
  71                 "LPRng lpc: do control operation",
  72                 "LPRng lpr: transfer a block format print job",
  73                 "LPRng lpc: secure command transfer",
  74                 "LPRng lpq: verbose status information"
  75         };
  76         static char     *lpd_server_code[] = {
  77                 "Success: accepted, proceed",
  78                 "Queue not accepting jobs",
  79                 "Queue temporarily full, retry later",
  80                 "Bad job format, do not retry"
  81         };
  82
  83         if (check_col(pinfo->cinfo, COL_PROTOCOL))
  84                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "LPD");
  85         if (check_col(pinfo->cinfo, COL_INFO))
  86                 col_clear(pinfo->cinfo, COL_INFO);
  87
  88         /* rfc1179 states that all responses are 1 byte long */
  89         code = tvb_get_guint8(tvb, 0);
  90         if (tvb_reported_length(tvb) == 1) {
  91                 lpr_packet_type = response;
  92         }
  93         else if (code <= 9) {
  94                 lpr_packet_type = request;
  95         }
  96         else {
  97                 lpr_packet_type = unknown;
  98         }
  99
 100         if (check_col(pinfo->cinfo, COL_INFO)) {
 101                 if (lpr_packet_type == request) {
 102                         col_set_str(pinfo->cinfo, COL_INFO, lpd_client_code[code]);
 103                 }
 104                 else if (lpr_packet_type == response) {
 105                         col_set_str(pinfo->cinfo, COL_INFO, "LPD response");
 106                 }
 107                 else {
 108                         col_set_str(pinfo->cinfo, COL_INFO, "LPD continuation");
 109                 }
 110         }
 111
 112         if (tree) {
 113                 ti = proto_tree_add_item(tree, proto_lpd, tvb, 0, -1, FALSE);
 114                 lpd_tree = proto_item_add_subtree(ti, ett_lpd);
 115
 116                 if (lpr_packet_type == response) {
 117                   proto_tree_add_boolean_hidden(lpd_tree, hf_lpd_response,
 118                                                 tvb, 0, 0, TRUE);
 119                 } else {
 120                   proto_tree_add_boolean_hidden(lpd_tree, hf_lpd_request,
 121                                                 tvb, 0, 0, TRUE);
 122                 }
 123
 124                 if (lpr_packet_type == request) {
 125                         printer_len = find_printer_string(tvb, 1);
 126
 127                         if (code <= 9 && printer_len != -1) {
 128                                 proto_tree_add_text(lpd_tree, tvb, 0, 1,
 129                                         lpd_client_code[code]);
 130                                 proto_tree_add_text(lpd_tree, tvb, 1, printer_len,
 131                                          "Printer/options: %s",
 132                                          tvb_format_text(tvb, 1, printer_len));
 133                         }
 134                         else {
 135                                 call_dissector(data_handle,tvb, pinfo, tree);
 136                         }
 137                 }
 138                 else if (lpr_packet_type == response) {
 139                         if (code <= 3) {
 140                                 proto_tree_add_text(lpd_tree, tvb, 0, 1,
 141                                         "Response: %s", lpd_server_code[code]);
 142                         }
 143                         else {
 144                                 call_dissector(data_handle,tvb, pinfo, tree);
 145                         }
 146                 }
 147                 else {
 148                         call_dissector(data_handle,tvb, pinfo, tree);
 149                 }
 150         }
 151 }
 152
 153
 154 static gint
 155 find_printer_string(tvbuff_t *tvb, int offset)
 156 {
 157         int     i;
 158
 159         /* try to find end of string, either '\n' or '\0' */
 160         i = tvb_find_guint8(tvb, offset, -1, '\0');
 161         if (i == -1)
 162                 i = tvb_find_guint8(tvb, offset, -1, '\n');
 163         if (i == -1)
 164                 return -1;
 165         return i - offset;      /* length of string */
 166 }
 167
 168
 169 void
 170 proto_register_lpd(void)
 171 {
 172   static hf_register_info hf[] = {
 173     { &hf_lpd_response,
 174       { "Response",           "lpd.response",
 175         FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 176         "TRUE if LPD response", HFILL }},
 177
 178     { &hf_lpd_request,
 179       { "Request",            "lpd.request",
 180         FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 181         "TRUE if LPD request", HFILL }}
 182   };
 183   static gint *ett[] = {
 184     &ett_lpd,
 185   };
 186
 187   proto_lpd = proto_register_protocol("Line Printer Daemon Protocol", "LPD", "lpd");
 188   proto_register_field_array(proto_lpd, hf, array_length(hf));
 189   proto_register_subtree_array(ett, array_length(ett));
 190 }
 191
 192 void
 193 proto_reg_handoff_lpd(void)
 194 {
 195   dissector_handle_t lpd_handle;
 196
 197   lpd_handle = create_dissector_handle(dissect_lpd, proto_lpd);
 198   dissector_add("tcp.port", TCP_PORT_PRINTER, lpd_handle);
 199   data_handle = find_dissector("data");
 200 }