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 #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         { AF_INET6,             "IPv6" },
  43         { 0,                            NULL }
  44 };
  45
  46 static inline void
  47 nflog_hdr_print(struct netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
  48 {
  49         ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
  50
  51         if (!ndo->ndo_qflag) {
  52                 ND_PRINT((ndo,", family %s (%d)",
  53                                                   tok2str(nflog_values, "Unknown",
  54                                                                   hdr->nflog_family),
  55                                                   hdr->nflog_family));
  56                 } else {
  57                 ND_PRINT((ndo,", %s",
  58                                                   tok2str(nflog_values,
  59                                                                   "Unknown NFLOG (0x%02x)",
  60                                                                   hdr->nflog_family)));
  61                 }
  62
  63         ND_PRINT((ndo, ", length %u: ", length));
  64 }
  65
  66 u_int
  67 nflog_if_print(struct netdissect_options *ndo,
  68                            const struct pcap_pkthdr *h, const u_char *p)
  69 {
  70         const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
  71         const nflog_tlv_t *tlv;
  72         u_int16_t size;
  73         u_int16_t h_size = sizeof(nflog_hdr_t);
  74         u_int caplen = h->caplen;
  75         u_int length = h->len;
  76
  77         if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
  78                 ND_PRINT((ndo, "[|nflog]"));
  79                 return h_size;
  80         }
  81
  82         if (!(hdr->nflog_version) == 0) {
  83                 ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
  84                 return h_size;
  85         }
  86
  87         if (ndo->ndo_eflag)
  88                 nflog_hdr_print(ndo, hdr, length);
  89
  90         p += sizeof(nflog_hdr_t);
  91         length -= sizeof(nflog_hdr_t);
  92         caplen -= sizeof(nflog_hdr_t);
  93
  94         while (length > 0) {
  95                 /* We have some data.  Do we have enough for the TLV header? */
  96                 if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
  97                         /* No. */
  98                         ND_PRINT((ndo, "[|nflog]"));
  99                         return h_size;
 100                 }
 101
 102                 tlv = (const nflog_tlv_t *) p;
 103                 size = tlv->tlv_length;
 104                 if (size % 4 != 0)
 105                         size += 4 - size % 4;
 106
 107                 /* Is the TLV's length less than the minimum? */
 108                 if (size < sizeof(nflog_tlv_t)) {
 109                         /* Yes. Give up now. */
 110                         ND_PRINT((ndo, "[|nflog]"));
 111                         return h_size;
 112                 }
 113
 114                 /* Do we have enough data for the full TLV? */
 115                 if (caplen < size || length < size) {
 116                         /* No. */
 117                         ND_PRINT((ndo, "[|nflog]"));
 118                         return h_size;
 119                 }
 120
 121                 if (tlv->tlv_type == NFULA_PAYLOAD) {
 122                         /*
 123                          * This TLV's data is the packet payload.
 124                          * Skip past the TLV header, and break out
 125                          * of the loop so we print the packet data.
 126                          */
 127                         p += sizeof(nflog_tlv_t);
 128                         h_size += sizeof(nflog_tlv_t);
 129                         length -= sizeof(nflog_tlv_t);
 130                         caplen -= sizeof(nflog_tlv_t);
 131                         break;
 132                 }
 133
 134                 p += size;
 135                 h_size += size;
 136                 length -= size;
 137                 caplen -= size;
 138         }
 139
 140         switch (hdr->nflog_family) {
 141
 142         case AF_INET:
 143                 ip_print(ndo, p, length);
 144                 break;
 145
 146 #ifdef INET6
 147         case AF_INET6:
 148                 ip6_print(ndo, p, length);
 149                 break;
 150 #endif /*INET6*/
 151
 152         default:
 153                 if (!ndo->ndo_eflag)
 154                         nflog_hdr_print(ndo, hdr,
 155                                 length + sizeof(nflog_hdr_t));
 156
 157                 if (!ndo->ndo_suppress_default_print)
 158                         ND_DEFAULTPRINT(p, caplen);
 159                 break;
 160         }
 161
 162         return h_size;
 163 }
 164
 165 #endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */