epan/dissectors/packet-lpd.c

   1 /* packet-lpd.c
   2  * Routines for LPR and LPRng packet disassembly
   3  * Gilbert Ramirez <gram@alumni.rice.edu>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <glib.h>
  29 #include <epan/packet.h>
  30
  31 #define TCP_PORT_PRINTER                515
  32
  33 static int proto_lpd = -1;
  34 static int hf_lpd_response = -1;
  35 static int hf_lpd_request = -1;
  36
  37 static gint ett_lpd = -1;
  38
  39 enum lpr_type { request, response, unknown };
  40
  41 static gint find_printer_string(tvbuff_t *tvb, int offset);
  42
  43 static dissector_handle_t data_handle;
  44
  45 static void
  46 dissect_lpd(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  47 {
  48         proto_tree      *lpd_tree;
  49         proto_item      *ti, *hidden_item;
  50         enum lpr_type   lpr_packet_type;
  51         guint8          code;
  52         gint            printer_len;
  53
  54         /* This information comes from the LPRng HOWTO, which also describes
  55                 RFC 1179. http://www.astart.com/lprng/LPRng-HOWTO.html */
  56         static const value_string lpd_client_code[] = {
  57                 { 1, "LPC: start print / jobcmd: abort" },
  58                 { 2, "LPR: transfer a printer job / jobcmd: receive control file" },
  59                 { 3, "LPQ: print short form of queue status / jobcmd: receive data file" },
  60                 { 4, "LPQ: print long form of queue status" },
  61                 { 5, "LPRM: remove jobs" },
  62                 { 6, "LPRng lpc: do control operation" },
  63                 { 7, "LPRng lpr: transfer a block format print job" },
  64                 { 8, "LPRng lpc: secure command transfer" },
  65                 { 9, "LPRng lpq: verbose status information" },
  66                 { 0, NULL }
  67         };
  68         static const value_string lpd_server_code[] = {
  69                 { 0, "Success: accepted, proceed" },
  70                 { 1, "Queue not accepting jobs" },
  71                 { 2, "Queue temporarily full, retry later" },
  72                 { 3, "Bad job format, do not retry" },
  73                 { 0, NULL }
  74         };
  75
  76         col_set_str(pinfo->cinfo, COL_PROTOCOL, "LPD");
  77         col_clear(pinfo->cinfo, COL_INFO);
  78
  79         /* rfc1179 states that all responses are 1 byte long */
  80         code = tvb_get_guint8(tvb, 0);
  81         if (tvb_reported_length(tvb) == 1) {
  82                 lpr_packet_type = response;
  83         }
  84         else if (code <= 9) {
  85                 lpr_packet_type = request;
  86         }
  87         else {
  88                 lpr_packet_type = unknown;
  89         }
  90
  91         if (lpr_packet_type == request && code !=0) {
  92                 col_add_str(pinfo->cinfo, COL_INFO, val_to_str(code, lpd_client_code, "Unknown client code: %u"));
  93         }
  94         else if (lpr_packet_type == response) {
  95                 col_set_str(pinfo->cinfo, COL_INFO, "LPD response");
  96         }
  97         else {
  98                 col_set_str(pinfo->cinfo, COL_INFO, "LPD continuation");
  99         }
 100
 101         if (tree) {
 102                 ti = proto_tree_add_item(tree, proto_lpd, tvb, 0, -1, ENC_NA);
 103                 lpd_tree = proto_item_add_subtree(ti, ett_lpd);
 104
 105                 if (lpr_packet_type == response) {
 106                   hidden_item = proto_tree_add_boolean(lpd_tree, hf_lpd_response,
 107                                                 tvb, 0, 0, TRUE);
 108                 } else {
 109                   hidden_item = proto_tree_add_boolean(lpd_tree, hf_lpd_request,
 110                                                 tvb, 0, 0, TRUE);
 111                 }
 112                 PROTO_ITEM_SET_HIDDEN(hidden_item);
 113
 114                 if (lpr_packet_type == request) {
 115                         printer_len = find_printer_string(tvb, 1);
 116
 117                         if (code <= 9 && printer_len != -1) {
 118                                 proto_tree_add_text(lpd_tree, tvb, 0, 1, "%s",
 119                                         val_to_str(code, lpd_client_code, "Unknown client code: %u"));
 120                                 proto_tree_add_text(lpd_tree, tvb, 1, printer_len,
 121                                          "Printer/options: %s",
 122                                          tvb_format_text(tvb, 1, printer_len));
 123                         }
 124                         else {
 125                                 call_dissector(data_handle,tvb, pinfo, lpd_tree);
 126                         }
 127                 }
 128                 else if (lpr_packet_type == response) {
 129                         if (code <= 3) {
 130                                 proto_tree_add_text(lpd_tree, tvb, 0, 1,
 131                                         "Response: %s", val_to_str(code, lpd_server_code, "Unknown server code: %u"));
 132                         }
 133                         else {
 134                                 call_dissector(data_handle,tvb, pinfo, lpd_tree);
 135                         }
 136                 }
 137                 else {
 138                         call_dissector(data_handle,tvb, pinfo, lpd_tree);
 139                 }
 140         }
 141 }
 142
 143
 144 static gint
 145 find_printer_string(tvbuff_t *tvb, int offset)
 146 {
 147         int     i;
 148
 149         /* try to find end of string, either '\n' or '\0' */
 150         i = tvb_find_guint8(tvb, offset, -1, '\0');
 151         if (i == -1)
 152                 i = tvb_find_guint8(tvb, offset, -1, '\n');
 153         if (i == -1)
 154                 return -1;
 155         return i - offset;      /* length of string */
 156 }
 157
 158
 159 void
 160 proto_register_lpd(void)
 161 {
 162   static hf_register_info hf[] = {
 163     { &hf_lpd_response,
 164       { "Response",           "lpd.response",
 165         FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 166         "TRUE if LPD response", HFILL }},
 167
 168     { &hf_lpd_request,
 169       { "Request",            "lpd.request",
 170         FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 171         "TRUE if LPD request", HFILL }}
 172   };
 173   static gint *ett[] = {
 174     &ett_lpd,
 175   };
 176
 177   proto_lpd = proto_register_protocol("Line Printer Daemon Protocol", "LPD", "lpd");
 178   proto_register_field_array(proto_lpd, hf, array_length(hf));
 179   proto_register_subtree_array(ett, array_length(ett));
 180 }
 181
 182 void
 183 proto_reg_handoff_lpd(void)
 184 {
 185   dissector_handle_t lpd_handle;
 186
 187   lpd_handle = create_dissector_handle(dissect_lpd, proto_lpd);
 188   dissector_add_uint("tcp.port", TCP_PORT_PRINTER, lpd_handle);
 189   data_handle = find_dissector("data");
 190 }