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 <stdio.h>
  35 #include <pcap.h>
  36
  37 #include "netdissect.h"
  38 #include "interface.h"
  39
  40 #include "nflog.h"
  41
  42 #ifdef DLT_NFLOG
  43
  44 #define NFULA_PAYLOAD 9
  45
  46 static const struct tok nflog_values[] = {
  47         { AF_INET,              "IPv4" },
  48         { AF_INET6,             "IPv6" },
  49         { 0,                            NULL }
  50 };
  51
  52 static inline void
  53 nflog_hdr_print(struct netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
  54 {
  55         ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
  56
  57         if (!ndo->ndo_qflag) {
  58                 ND_PRINT((ndo,", family %s (%d)",
  59                                                   tok2str(nflog_values, "Unknown",
  60                                                                   hdr->nflog_family),
  61                                                   hdr->nflog_family));
  62                 } else {
  63                 ND_PRINT((ndo,", %s",
  64                                                   tok2str(nflog_values,
  65                                                                   "Unknown NFLOG (0x%02x)",
  66                                                                   hdr->nflog_family)));
  67                 }
  68
  69         ND_PRINT((ndo, ", length %u: ", length));
  70 }
  71
  72 u_int
  73 nflog_if_print(struct netdissect_options *ndo,
  74                            const struct pcap_pkthdr *h, const u_char *p)
  75 {
  76         const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
  77         const nflog_tlv_t *tlv;
  78         u_int16_t size;
  79         u_int16_t h_size = sizeof(nflog_hdr_t);
  80         u_int caplen = h->caplen;
  81         u_int length = h->len;
  82
  83         if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
  84                 ND_PRINT((ndo, "[|nflog]"));
  85                 return h_size;
  86         }
  87
  88         if (!(hdr->nflog_version) == 0) {
  89                 ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
  90                 return h_size;
  91         }
  92
  93         if (ndo->ndo_eflag)
  94                 nflog_hdr_print(ndo, hdr, length);
  95
  96         length -= sizeof(nflog_hdr_t);
  97         caplen -= sizeof(nflog_hdr_t);
  98         p += sizeof(nflog_hdr_t);
  99
 100         do {
 101                 tlv = (const nflog_tlv_t *) p;
 102                 size = tlv->tlv_length;
 103
 104                 if (size % 4 != 0)
 105                         size += 4 - size % 4;
 106
 107                 h_size = h_size + size;
 108
 109                 /* wrong size of the packet */
 110                 if (size > length || size == 0)
 111                         return h_size;
 112
 113                 p += size;
 114                 length = length - size;
 115                 caplen = caplen - size;
 116
 117         } while (tlv->tlv_type != NFULA_PAYLOAD);
 118
 119         /* dont skip payload just tlv length and type */
 120         p = p - size + 4;
 121         length += size - 4;
 122         caplen += size - 4;
 123         h_size -= length;
 124
 125         switch (hdr->nflog_family) {
 126
 127         case AF_INET:
 128                         ip_print(ndo, p, length);
 129                 break;
 130
 131 #ifdef INET6
 132         case AF_INET6:
 133                 ip6_print(ndo, p, length);
 134                 break;
 135 #endif /*INET6*/
 136
 137         default:
 138                 if (!ndo->ndo_eflag)
 139                         nflog_hdr_print(ndo, hdr,
 140                                 length + sizeof(nflog_hdr_t));
 141
 142                 if (!ndo->ndo_suppress_default_print)
 143                         ndo->ndo_default_print(ndo, p, caplen);
 144                 break;
 145         }
 146
 147         return h_size;
 148 }
 149
 150 #endif /* DLT_NFLOG */