epan/dissectors/packet-nntp.c

   1 /* packet-nntp.c
   2  * Routines for nntp packet dissection
   3  * Copyright 1999, Richard Sharpe <rsharpe@ns.aus.com>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 #include "config.h"
  13
  14 #include <epan/packet.h>
  15
  16 #include "packet-tls-utils.h"
  17
  18 void proto_register_nntp(void);
  19 void proto_reg_handoff_nntp(void);
  20
  21 static int proto_nntp;
  22 static int hf_nntp_response;
  23 static int hf_nntp_request;
  24
  25 static int ett_nntp;
  26
  27 static dissector_handle_t nntp_handle;
  28 static dissector_handle_t tls_handle;
  29
  30 #define TCP_PORT_NNTP                   119
  31
  32 /* State of NNTP conversation */
  33 typedef struct nntp_conversation_t {
  34         bool tls_requested;
  35 } nntp_conversation_t;
  36
  37 static int
  38 dissect_nntp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  39 {
  40         const char      *type;
  41         proto_tree      *nntp_tree;
  42         proto_item      *ti;
  43         int             offset = 0;
  44         int             next_offset;
  45         const unsigned char    *line;
  46         int             linelen;
  47         conversation_t  *conversation;
  48         nntp_conversation_t *session_state;
  49
  50         conversation = find_or_create_conversation(pinfo);
  51         session_state = (nntp_conversation_t *)conversation_get_proto_data(conversation, proto_nntp);
  52         if (!session_state) {
  53                 session_state = wmem_new0(wmem_file_scope(), nntp_conversation_t);
  54                 session_state->tls_requested = false;
  55                 conversation_add_proto_data(conversation, proto_nntp, session_state);
  56         }
  57
  58         if (pinfo->match_uint == pinfo->destport)
  59                 type = "Request";
  60         else
  61                 type = "Response";
  62
  63         col_set_str(pinfo->cinfo, COL_PROTOCOL, "NNTP");
  64
  65         /*
  66          * Put the first line from the buffer into the summary
  67          * (but leave out the line terminator).
  68          *
  69          * Note that "tvb_find_line_end()" will return a value that
  70          * is not longer than what's in the buffer, so the
  71          * "tvb_get_ptr()" call won't throw an exception.
  72          */
  73         linelen = tvb_find_line_end(tvb, offset, -1, &next_offset, false);
  74         line    = tvb_get_ptr(tvb, offset, linelen);
  75         col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %s", type,
  76                     tvb_format_text(pinfo->pool, tvb, offset, linelen));
  77
  78         ti = proto_tree_add_item(tree, proto_nntp, tvb, offset, -1, ENC_NA);
  79         nntp_tree = proto_item_add_subtree(ti, ett_nntp);
  80
  81         if (pinfo->match_uint == pinfo->destport) {
  82                 ti = proto_tree_add_boolean(nntp_tree, hf_nntp_request, tvb, 0, 0, true);
  83
  84                 if (line && g_ascii_strncasecmp(line, "STARTTLS", 8) == 0) {
  85                         session_state->tls_requested = true;
  86                 }
  87         } else {
  88                 ti = proto_tree_add_boolean(nntp_tree, hf_nntp_response, tvb, 0, 0, true);
  89
  90                 if (session_state->tls_requested) {
  91                         if (line && g_ascii_strncasecmp(line, "382", 3) == 0) {
  92                                 /* STARTTLS command accepted */
  93                                 ssl_starttls_ack(tls_handle, pinfo, nntp_handle);
  94                         }
  95                         session_state->tls_requested = false;
  96                 }
  97         }
  98         proto_item_set_hidden(ti);
  99
 100         /*
 101          * Show the request or response as text, a line at a time.
 102          * XXX - for requests, we could display the stuff after the
 103          * first line, if any, based on what the request was, and
 104          * for responses, we could display it based on what the
 105          * matching request was, although the latter requires us to
 106          * know what the matching request was....
 107          */
 108         while (tvb_offset_exists(tvb, offset)) {
 109                 /*
 110                  * Find the end of the line.
 111                  */
 112                 tvb_find_line_end(tvb, offset, -1, &next_offset, false);
 113
 114                 /*
 115                  * Put this line.
 116                  */
 117                 proto_tree_add_format_text(nntp_tree, tvb, offset, next_offset - offset);
 118                 offset = next_offset;
 119         }
 120
 121         return tvb_captured_length(tvb);
 122 }
 123
 124 void
 125 proto_register_nntp(void)
 126 {
 127         static hf_register_info hf[] = {
 128                 { &hf_nntp_response,
 129                 { "Response",           "nntp.response",
 130                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 131                         "true if NNTP response", HFILL }},
 132
 133                 { &hf_nntp_request,
 134                 { "Request",            "nntp.request",
 135                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 136                         "true if NNTP request", HFILL }}
 137         };
 138         static int *ett[] = {
 139                 &ett_nntp,
 140         };
 141
 142         proto_nntp = proto_register_protocol("Network News Transfer Protocol",
 143             "NNTP", "nntp");
 144         proto_register_field_array(proto_nntp, hf, array_length(hf));
 145         proto_register_subtree_array(ett, array_length(ett));
 146 }
 147
 148 void
 149 proto_reg_handoff_nntp(void)
 150 {
 151         nntp_handle = register_dissector("nntp", dissect_nntp, proto_nntp);
 152         dissector_add_uint_with_preference("tcp.port", TCP_PORT_NNTP, nntp_handle);
 153
 154         tls_handle = find_dissector("tls");
 155 }
 156
 157 /*
 158  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 159  *
 160  * Local variables:
 161  * c-basic-offset: 8
 162  * tab-width: 8
 163  * indent-tabs-mode: t
 164  * End:
 165  *
 166  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 167  * :indentSize=8:tabSize=8:noTabs=false:
 168  */