contrib/tcpdump/print-nflog.c

   1 /*
   2  * Copyright (c) 2013, Petar Alilovic,
   3  * Faculty of Electrical Engineering and Computing, University of Zagreb
   4  * All rights reserved
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * * Redistributions of source code must retain the above copyright notice,
  10  *       this list of conditions and the following disclaimer.
  11  * * Redistributions in binary form must reproduce the above copyright
  12  *       notice, this list of conditions and the following disclaimer in the
  13  *       documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
  19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  22  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  25  * DAMAGE.
  26  */
  27
  28 #define NETDISSECT_REWORKED
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <tcpdump-stdinc.h>
  34
  35 #include "interface.h"
  36
  37 #if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
  38 #include <pcap/nflog.h>
  39
  40 static const struct tok nflog_values[] = {
  41         { AF_INET,              "IPv4" },
  42 #ifdef INET6
  43         { AF_INET6,             "IPv6" },
  44 #endif /*INET6*/
  45         { 0,                    NULL }
  46 };
  47
  48 static inline void
  49 nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
  50 {
  51         ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
  52
  53         if (!ndo->ndo_qflag) {
  54                 ND_PRINT((ndo,", family %s (%d)",
  55                                                   tok2str(nflog_values, "Unknown",
  56                                                                   hdr->nflog_family),
  57                                                   hdr->nflog_family));
  58                 } else {
  59                 ND_PRINT((ndo,", %s",
  60                                                   tok2str(nflog_values,
  61                                                                   "Unknown NFLOG (0x%02x)",
  62                                                                   hdr->nflog_family)));
  63                 }
  64
  65         ND_PRINT((ndo, ", length %u: ", length));
  66 }
  67
  68 u_int
  69 nflog_if_print(netdissect_options *ndo,
  70                            const struct pcap_pkthdr *h, const u_char *p)
  71 {
  72         const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
  73         const nflog_tlv_t *tlv;
  74         uint16_t size;
  75         uint16_t h_size = sizeof(nflog_hdr_t);
  76         u_int caplen = h->caplen;
  77         u_int length = h->len;
  78
  79         if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
  80                 ND_PRINT((ndo, "[|nflog]"));
  81                 return h_size;
  82         }
  83
  84         if (!(hdr->nflog_version) == 0) {
  85                 ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
  86                 return h_size;
  87         }
  88
  89         if (ndo->ndo_eflag)
  90                 nflog_hdr_print(ndo, hdr, length);
  91
  92         p += sizeof(nflog_hdr_t);
  93         length -= sizeof(nflog_hdr_t);
  94         caplen -= sizeof(nflog_hdr_t);
  95
  96         while (length > 0) {
  97                 /* We have some data.  Do we have enough for the TLV header? */
  98                 if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
  99                         /* No. */
 100                         ND_PRINT((ndo, "[|nflog]"));
 101                         return h_size;
 102                 }
 103
 104                 tlv = (const nflog_tlv_t *) p;
 105                 size = tlv->tlv_length;
 106                 if (size % 4 != 0)
 107                         size += 4 - size % 4;
 108
 109                 /* Is the TLV's length less than the minimum? */
 110                 if (size < sizeof(nflog_tlv_t)) {
 111                         /* Yes. Give up now. */
 112                         ND_PRINT((ndo, "[|nflog]"));
 113                         return h_size;
 114                 }
 115
 116                 /* Do we have enough data for the full TLV? */
 117                 if (caplen < size || length < size) {
 118                         /* No. */
 119                         ND_PRINT((ndo, "[|nflog]"));
 120                         return h_size;
 121                 }
 122
 123                 if (tlv->tlv_type == NFULA_PAYLOAD) {
 124                         /*
 125                          * This TLV's data is the packet payload.
 126                          * Skip past the TLV header, and break out
 127                          * of the loop so we print the packet data.
 128                          */
 129                         p += sizeof(nflog_tlv_t);
 130                         h_size += sizeof(nflog_tlv_t);
 131                         length -= sizeof(nflog_tlv_t);
 132                         caplen -= sizeof(nflog_tlv_t);
 133                         break;
 134                 }
 135
 136                 p += size;
 137                 h_size += size;
 138                 length -= size;
 139                 caplen -= size;
 140         }
 141
 142         switch (hdr->nflog_family) {
 143
 144         case AF_INET:
 145                 ip_print(ndo, p, length);
 146                 break;
 147
 148 #ifdef AF_INET6
 149         case AF_INET6:
 150                 ip6_print(ndo, p, length);
 151                 break;
 152 #endif /* AF_INET6 */
 153
 154         default:
 155                 if (!ndo->ndo_eflag)
 156                         nflog_hdr_print(ndo, hdr,
 157                                 length + sizeof(nflog_hdr_t));
 158
 159                 if (!ndo->ndo_suppress_default_print)
 160                         ND_DEFAULTPRINT(p, caplen);
 161                 break;
 162         }
 163
 164         return h_size;
 165 }
 166
 167 #endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */