epan/dissectors/packet-nflog.c

   1 /* packet-nflog.c
   2  * Copyright 2011,2012 Jakub Zawadzki <darkjames-ws@darkjames.pl>
   3  *
   4  * Wireshark - Network traffic analyzer
   5  * By Gerald Combs <gerald@wireshark.org>
   6  * Copyright 1998
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define NEW_PROTO_TREE_API
  24
  25 #include "config.h"
  26
  27 #include <glib.h>
  28
  29 #include <epan/packet.h>
  30 #include <epan/prefs.h>
  31 #include <epan/aftypes.h>
  32 #include <wiretap/wtap.h>
  33
  34 void proto_register_nflog(void);
  35 void proto_reg_handoff_nflog(void);
  36
  37 /* nfulnl_attr_type enum from <linux/netfilter/nfnetlink_log.h> */
  38 enum ws_nfulnl_attr_type {
  39     WS_NFULA_UNSPEC,
  40     WS_NFULA_PACKET_HDR,
  41     WS_NFULA_MARK,               /* __u32 nfmark */
  42     WS_NFULA_TIMESTAMP,          /* nfulnl_msg_packet_timestamp */
  43     WS_NFULA_IFINDEX_INDEV,      /* __u32 ifindex */
  44     WS_NFULA_IFINDEX_OUTDEV,     /* __u32 ifindex */
  45     WS_NFULA_IFINDEX_PHYSINDEV,  /* __u32 ifindex */
  46     WS_NFULA_IFINDEX_PHYSOUTDEV, /* __u32 ifindex */
  47     WS_NFULA_HWADDR,             /* nfulnl_msg_packet_hw */
  48     WS_NFULA_PAYLOAD,            /* opaque data payload */
  49     WS_NFULA_PREFIX,             /* string prefix */
  50     WS_NFULA_UID,                /* user id of socket */
  51     WS_NFULA_SEQ,                /* instance-local sequence number */
  52     WS_NFULA_SEQ_GLOBAL,         /* global sequence number */
  53     WS_NFULA_GID,                /* group id of socket */
  54     WS_NFULA_HWTYPE,             /* hardware type */
  55     WS_NFULA_HWHEADER,           /* hardware header */
  56     WS_NFULA_HWLEN               /* hardware header length */
  57 };
  58
  59 static const value_string nflog_tlv_vals[] = {
  60     { WS_NFULA_UNSPEC,             "NFULA_UNSPEC" },
  61     { WS_NFULA_PACKET_HDR,         "NFULA_PACKET_HDR" },
  62     { WS_NFULA_MARK,               "NFULA_MARK" },
  63     { WS_NFULA_TIMESTAMP,          "NFULA_TIMESTAMP" },
  64     { WS_NFULA_IFINDEX_INDEV,      "NFULA_IFINDEX_INDEV" },
  65     { WS_NFULA_IFINDEX_OUTDEV,     "NFULA_IFINDEX_OUTDEV" },
  66     { WS_NFULA_IFINDEX_PHYSINDEV,  "NFULA_IFINDEX_PHYSINDEV" },
  67     { WS_NFULA_IFINDEX_PHYSOUTDEV, "NFULA_IFINDEX_PHYSOUTDEV" },
  68     { WS_NFULA_HWADDR,             "NFULA_HWADDR" },
  69     { WS_NFULA_PAYLOAD,            "NFULA_PAYLOAD" },
  70     { WS_NFULA_PREFIX,             "NFULA_PREFIX" },
  71     { WS_NFULA_UID,                "NFULA_UID" },
  72     { WS_NFULA_SEQ,                "NFULA_SEQ" },
  73     { WS_NFULA_SEQ_GLOBAL,         "NFULA_SEQ_GLOBAL" },
  74     { WS_NFULA_GID,                "NFULA_GID" },
  75     { WS_NFULA_HWTYPE,             "NFULA_HWTYPE" },
  76     { WS_NFULA_HWHEADER,           "NFULA_HWHEADER" },
  77     { WS_NFULA_HWLEN,              "NFULA_HWLEN" },
  78     { 0, NULL }
  79 };
  80
  81 static int ett_nflog = -1;
  82 static int ett_nflog_tlv = -1;
  83
  84 static header_field_info *hfi_nflog = NULL;
  85
  86 #define NFLOG_HFI_INIT HFI_INIT(proto_nflog)
  87
  88 /* Header */
  89 static header_field_info hfi_nflog_family NFLOG_HFI_INIT =
  90     { "Family", "nflog.family", FT_UINT8, BASE_DEC | BASE_EXT_STRING, &linux_af_vals_ext, 0x00, NULL, HFILL };
  91
  92 static header_field_info hfi_nflog_version NFLOG_HFI_INIT =
  93     { "Version", "nflog.version", FT_UINT8, BASE_DEC, NULL, 0x00, NULL, HFILL };
  94
  95 static header_field_info hfi_nflog_resid NFLOG_HFI_INIT =
  96     { "Resource id", "nflog.res_id", FT_UINT16, BASE_DEC, NULL, 0x00, NULL, HFILL };
  97
  98 /* TLV */
  99 static header_field_info hfi_nflog_tlv NFLOG_HFI_INIT =
 100     { "TLV", "nflog.tlv", FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL };
 101
 102 static header_field_info hfi_nflog_tlv_length NFLOG_HFI_INIT =
 103     { "Length", "nflog.tlv_length", FT_UINT16, BASE_DEC, NULL, 0x00, "TLV Length", HFILL };
 104
 105 static header_field_info hfi_nflog_tlv_type NFLOG_HFI_INIT =
 106     { "Type", "nflog.tlv_type", FT_UINT16, BASE_DEC, VALS(nflog_tlv_vals), 0x7fff, "TLV Type", HFILL };
 107
 108 /* TLV values */
 109 static header_field_info hfi_nflog_tlv_prefix NFLOG_HFI_INIT =
 110     { "Prefix", "nflog.prefix", FT_STRINGZ, BASE_NONE, NULL, 0x00, "TLV Prefix Value", HFILL };
 111
 112 static header_field_info hfi_nflog_tlv_uid NFLOG_HFI_INIT =
 113     { "UID", "nflog.uid", FT_INT32, BASE_DEC, NULL, 0x00, "TLV UID Value", HFILL };
 114
 115 static header_field_info hfi_nflog_tlv_gid NFLOG_HFI_INIT =
 116     { "GID", "nflog.gid", FT_INT32, BASE_DEC, NULL, 0x00, "TLV GID Value", HFILL };
 117
 118 static header_field_info hfi_nflog_tlv_timestamp NFLOG_HFI_INIT =
 119     { "Timestamp", "nflog.timestamp", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00, "TLV Timestamp Value", HFILL };
 120
 121 static header_field_info hfi_nflog_tlv_unknown NFLOG_HFI_INIT =
 122     { "Value", "nflog.tlv_value", FT_BYTES, BASE_NONE, NULL, 0x00, "TLV Value", HFILL };
 123
 124 static dissector_handle_t ip_handle;
 125 static dissector_handle_t ip6_handle;
 126 static dissector_handle_t data_handle;
 127
 128 static void
 129 dissect_nflog(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 130 {
 131     const int start_tlv_offset = 4;
 132
 133     proto_tree *nflog_tree = NULL;
 134     proto_item *ti;
 135
 136     int offset = 0;
 137
 138     tvbuff_t *next_tvb = NULL;
 139     int aftype;
 140
 141     col_set_str(pinfo->cinfo, COL_PROTOCOL, "NFLOG");
 142     col_clear(pinfo->cinfo, COL_INFO);
 143
 144     aftype = tvb_get_guint8(tvb, 0);
 145
 146     /* Header */
 147     if (proto_field_is_referenced(tree, hfi_nflog->id)) {
 148         ti = proto_tree_add_item(tree, hfi_nflog, tvb, 0, -1, ENC_NA);
 149         nflog_tree = proto_item_add_subtree(ti, ett_nflog);
 150
 151         proto_tree_add_item(nflog_tree, &hfi_nflog_family, tvb, offset, 1, ENC_NA);
 152         offset += 1;
 153
 154         proto_tree_add_item(nflog_tree, &hfi_nflog_version, tvb, offset, 1, ENC_NA);
 155         offset += 1;
 156
 157         proto_tree_add_item(nflog_tree, &hfi_nflog_resid, tvb, offset, 2, ENC_BIG_ENDIAN);
 158         /*offset += 2;*/
 159     }
 160
 161     offset = start_tlv_offset;
 162     /* TLVs */
 163     while (tvb_reported_length_remaining(tvb, offset) >= 4) {
 164         guint16 tlv_len = tvb_get_h_guint16(tvb, offset + 0);
 165         guint16 tlv_type;
 166         guint16 value_len;
 167
 168         proto_tree *tlv_tree;
 169
 170         /* malformed */
 171         if (tlv_len < 4)
 172             return;
 173
 174         value_len = tlv_len - 4;
 175         tlv_type = (tvb_get_h_guint16(tvb, offset + 2) & 0x7fff);
 176
 177         if (nflog_tree) {
 178             gboolean handled = FALSE;
 179
 180             ti = proto_tree_add_bytes_format(nflog_tree, hfi_nflog_tlv.id,
 181                              tvb, offset, tlv_len, NULL,
 182                              "TLV Type: %s (%u), Length: %u",
 183                              val_to_str_const(tlv_type, nflog_tlv_vals, "Unknown"),
 184                              tlv_type, tlv_len);
 185             tlv_tree = proto_item_add_subtree(ti, ett_nflog_tlv);
 186
 187             proto_tree_add_item(tlv_tree, &hfi_nflog_tlv_length, tvb, offset + 0, 2, ENC_HOST_ENDIAN);
 188             proto_tree_add_item(tlv_tree, &hfi_nflog_tlv_type, tvb, offset + 2, 2, ENC_HOST_ENDIAN);
 189             switch (tlv_type) {
 190                 case WS_NFULA_PAYLOAD:
 191                     handled = TRUE;
 192                     break;
 193
 194                 case WS_NFULA_PREFIX:
 195                     if (value_len >= 1) {
 196                         proto_tree_add_item(tlv_tree, &hfi_nflog_tlv_prefix,
 197                                     tvb, offset + 4, value_len, ENC_NA);
 198                         handled = TRUE;
 199                     }
 200                     break;
 201
 202                 case WS_NFULA_UID:
 203                     if (value_len == 4) {
 204                         proto_tree_add_item(tlv_tree, &hfi_nflog_tlv_uid,
 205                                     tvb, offset + 4, value_len, ENC_BIG_ENDIAN);
 206                         handled = TRUE;
 207                     }
 208                     break;
 209
 210                 case WS_NFULA_GID:
 211                     if (value_len == 4) {
 212                         proto_tree_add_item(tlv_tree, &hfi_nflog_tlv_gid,
 213                                     tvb, offset + 4, value_len, ENC_BIG_ENDIAN);
 214                         handled = TRUE;
 215                     }
 216                     break;
 217
 218                 case WS_NFULA_TIMESTAMP:
 219                     if (value_len == 16) {
 220                         nstime_t ts;
 221
 222                         ts.secs  = (time_t)tvb_get_ntoh64(tvb, offset + 4);
 223                         /* XXX - add an "expert info" warning if this is >= 10^9? */
 224                         ts.nsecs = (int)tvb_get_ntoh64(tvb, offset + 12);
 225                         proto_tree_add_time(tlv_tree, &hfi_nflog_tlv_timestamp,
 226                                     tvb, offset + 4, value_len, &ts);
 227                         handled = TRUE;
 228                     }
 229                     break;
 230             }
 231
 232             if (!handled)
 233                     proto_tree_add_item(tlv_tree, &hfi_nflog_tlv_unknown,
 234                                         tvb, offset + 4, value_len, ENC_NA);
 235         }
 236
 237         if (tlv_type == WS_NFULA_PAYLOAD)
 238             next_tvb = tvb_new_subset_length(tvb, offset + 4, value_len);
 239
 240         offset += ((tlv_len + 3) & ~3); /* next TLV aligned to 4B */
 241     }
 242
 243     if (next_tvb) {
 244         switch (aftype) {
 245             case LINUX_AF_INET:
 246                 call_dissector(ip_handle, next_tvb, pinfo, tree);
 247                 break;
 248             case LINUX_AF_INET6:
 249                 call_dissector(ip6_handle, next_tvb, pinfo, tree);
 250                 break;
 251             default:
 252                 call_dissector(data_handle, next_tvb, pinfo, tree);
 253                 break;
 254         }
 255     }
 256 }
 257
 258 void
 259 proto_register_nflog(void)
 260 {
 261 #ifndef HAVE_HFI_SECTION_INIT
 262     static header_field_info *hfi[] = {
 263     /* Header */
 264         &hfi_nflog_family,
 265         &hfi_nflog_version,
 266         &hfi_nflog_resid,
 267     /* TLV */
 268         &hfi_nflog_tlv,
 269         &hfi_nflog_tlv_length,
 270         &hfi_nflog_tlv_type,
 271     /* TLV values */
 272         &hfi_nflog_tlv_prefix,
 273         &hfi_nflog_tlv_uid,
 274         &hfi_nflog_tlv_gid,
 275         &hfi_nflog_tlv_timestamp,
 276         &hfi_nflog_tlv_unknown,
 277     };
 278 #endif
 279
 280     static gint *ett[] = {
 281         &ett_nflog,
 282         &ett_nflog_tlv
 283     };
 284
 285     int proto_nflog;
 286
 287     proto_nflog = proto_register_protocol("Linux Netfilter NFLOG", "NFLOG", "nflog");
 288     hfi_nflog = proto_registrar_get_nth(proto_nflog);
 289
 290     register_dissector("nflog", dissect_nflog, proto_nflog);
 291
 292     proto_register_fields(proto_nflog, hfi, array_length(hfi));
 293     proto_register_subtree_array(ett, array_length(ett));
 294
 295 }
 296
 297 void
 298 proto_reg_handoff_nflog(void)
 299 {
 300     dissector_handle_t nflog_handle;
 301
 302     ip_handle   = find_dissector("ip");
 303     ip6_handle  = find_dissector("ipv6");
 304     data_handle = find_dissector("data");
 305
 306     nflog_handle = find_dissector("nflog");
 307     dissector_add_uint("wtap_encap", WTAP_ENCAP_NFLOG, nflog_handle);
 308 }
 309
 310 /*
 311  * Editor modelines
 312  *
 313  * Local Variables:
 314  * c-basic-offset: 4
 315  * tab-width: 8
 316  * indent-tabs-mode: nil
 317  * End:
 318  *
 319  * ex: set shiftwidth=4 tabstop=8 expandtab:
 320  * :indentSize=4:tabSize=8:noTabs=true:
 321  */