src/proto_ip_authentication_hdr.h

   1 /*
   2  * IP Authentication Header described in RFC4302
   3  * programmed by Markus Amend 2012 as a contribution to
   4  * netsniff-ng - the packet sniffing beast
   5  * Copyright 2012 Markus Amend.
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 #ifndef PROTO_IP_AUTHENTICATION_HDR_H
  10 #define PROTO_IP_AUTHENTICATION_HDR_H
  11
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <netinet/in.h>    /* for ntohs() */
  15
  16 #include "proto_struct.h"
  17 #include "dissector_eth.h"
  18 #include "built_in.h"
  19
  20 struct auth_hdrhdr {
  21         uint8_t h_next_header;
  22         uint8_t h_payload_len;
  23         uint16_t h_reserved;
  24         uint32_t h_spi;
  25         uint32_t h_snf;
  26 } __packed;
  27
  28 static inline void auth_hdr(uint8_t *packet, size_t len)
  29 {
  30         uint8_t hdr_payload_len;
  31         struct auth_hdrhdr *auth_hdr = (struct auth_hdrhdr *) packet;
  32
  33         hdr_payload_len = (auth_hdr->h_payload_len * 4) + 8;
  34         if (len < hdr_payload_len || len < sizeof(struct auth_hdrhdr))
  35                 return;
  36
  37         tprintf(" [ Authentication Header ");
  38         tprintf("NextHdr (%u), ", auth_hdr->h_next_header);
  39         tprintf("HdrLen (%u), ", hdr_payload_len);
  40         tprintf("Reserved (0x%x), ", ntohs(auth_hdr->h_reserved));
  41         tprintf("SPI (0x%x), ", ntohl(auth_hdr->h_spi));
  42         tprintf("SNF (0x%x), ", ntohl(auth_hdr->h_snf));
  43         tprintf("ICV 0x");
  44         for (uint8_t i = sizeof(struct auth_hdrhdr); i < hdr_payload_len; i++)
  45                 tprintf("%02x",(uint8_t) packet[i]);
  46         tprintf(" ]\n");
  47 }
  48
  49 static inline void auth_hdr_less(uint8_t *packet, size_t len)
  50 {
  51         uint8_t hdr_payload_len;
  52         struct auth_hdrhdr *auth_hdr = (struct auth_hdrhdr *) packet;
  53
  54         hdr_payload_len = (auth_hdr->h_payload_len * 4) + 8;
  55         if (len < hdr_payload_len || len < sizeof(struct auth_hdrhdr))
  56                 return;
  57
  58         tprintf(" AH");
  59 }
  60
  61 static inline void auth_hdr_next(uint8_t *packet, size_t len,
  62                                  struct hash_table **table,
  63                                  unsigned int *key, size_t *off)
  64 {
  65         uint8_t hdr_payload_len;
  66         struct auth_hdrhdr *auth_hdr = (struct auth_hdrhdr *) packet;
  67
  68         hdr_payload_len = (auth_hdr->h_payload_len * 4) + 8;
  69         if (len < hdr_payload_len || len < sizeof(struct auth_hdrhdr))
  70                 return;
  71
  72         (*off) = hdr_payload_len;
  73         (*key) = auth_hdr->h_next_header;
  74         (*table) = &eth_lay3;
  75 }
  76
  77 struct protocol ip_auth_hdr_ops = {
  78         .key = 0x33,
  79         .print_full = auth_hdr,
  80         .print_less = auth_hdr_less,
  81         .proto_next = auth_hdr_next,
  82 };
  83
  84 #endif /* PROTO_IP_AUTHENTICATION_HDR_H */