The Tcpdump Group git mirrors - tcpdump/blob - 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 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <tcpdump-stdinc.h>
  33
  34 #include "netdissect.h"
  35
  36 #if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
  37 #include <pcap/nflog.h>
  38
  39 static const struct tok nflog_values[] = {
  40         { AF_INET,              "IPv4" },
  41 #ifdef INET6
  42         { AF_INET6,             "IPv6" },
  43 #endif /*INET6*/
  44         { 0,                    NULL }
  45 };
  46
  47 static inline void
  48 nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
  49 {
  50         ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
  51
  52         if (!ndo->ndo_qflag) {
  53                 ND_PRINT((ndo,", family %s (%d)",
  54                                                   tok2str(nflog_values, "Unknown",
  55                                                                   hdr->nflog_family),
  56                                                   hdr->nflog_family));
  57                 } else {
  58                 ND_PRINT((ndo,", %s",
  59                                                   tok2str(nflog_values,
  60                                                                   "Unknown NFLOG (0x%02x)",
  61                                                                   hdr->nflog_family)));
  62                 }
  63
  64         ND_PRINT((ndo, ", length %u: ", length));
  65 }
  66
  67 u_int
  68 nflog_if_print(netdissect_options *ndo,
  69                            const struct pcap_pkthdr *h, const u_char *p)
  70 {
  71         const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
  72         const nflog_tlv_t *tlv;
  73         uint16_t size;
  74         uint16_t h_size = sizeof(nflog_hdr_t);
  75         u_int caplen = h->caplen;
  76         u_int length = h->len;
  77
  78         if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
  79                 ND_PRINT((ndo, "[|nflog]"));
  80                 return h_size;
  81         }
  82
  83         if (!(hdr->nflog_version) == 0) {
  84                 ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
  85                 return h_size;
  86         }
  87
  88         if (ndo->ndo_eflag)
  89                 nflog_hdr_print(ndo, hdr, length);
  90
  91         p += sizeof(nflog_hdr_t);
  92         length -= sizeof(nflog_hdr_t);
  93         caplen -= sizeof(nflog_hdr_t);
  94
  95         while (length > 0) {
  96                 /* We have some data.  Do we have enough for the TLV header? */
  97                 if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
  98                         /* No. */
  99                         ND_PRINT((ndo, "[|nflog]"));
 100                         return h_size;
 101                 }
 102
 103                 tlv = (const nflog_tlv_t *) p;
 104                 size = tlv->tlv_length;
 105                 if (size % 4 != 0)
 106                         size += 4 - size % 4;
 107
 108                 /* Is the TLV's length less than the minimum? */
 109                 if (size < sizeof(nflog_tlv_t)) {
 110                         /* Yes. Give up now. */
 111                         ND_PRINT((ndo, "[|nflog]"));
 112                         return h_size;
 113                 }
 114
 115                 /* Do we have enough data for the full TLV? */
 116                 if (caplen < size || length < size) {
 117                         /* No. */
 118                         ND_PRINT((ndo, "[|nflog]"));
 119                         return h_size;
 120                 }
 121
 122                 if (tlv->tlv_type == NFULA_PAYLOAD) {
 123                         /*
 124                          * This TLV's data is the packet payload.
 125                          * Skip past the TLV header, and break out
 126                          * of the loop so we print the packet data.
 127                          */
 128                         p += sizeof(nflog_tlv_t);
 129                         h_size += sizeof(nflog_tlv_t);
 130                         length -= sizeof(nflog_tlv_t);
 131                         caplen -= sizeof(nflog_tlv_t);
 132                         break;
 133                 }
 134
 135                 p += size;
 136                 h_size += size;
 137                 length -= size;
 138                 caplen -= size;
 139         }
 140
 141         switch (hdr->nflog_family) {
 142
 143         case AF_INET:
 144                 ip_print(ndo, p, length);
 145                 break;
 146
 147 #ifdef AF_INET6
 148         case AF_INET6:
 149                 ip6_print(ndo, p, length);
 150                 break;
 151 #endif /* AF_INET6 */
 152
 153         default:
 154                 if (!ndo->ndo_eflag)
 155                         nflog_hdr_print(ndo, hdr,
 156                                 length + sizeof(nflog_hdr_t));
 157
 158                 if (!ndo->ndo_suppress_default_print)
 159                         ND_DEFAULTPRINT(p, caplen);
 160                 break;
 161         }
 162
 163         return h_size;
 164 }
 165
 166 #endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */