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 AUTHENTICATION_HEADER_H
  10 #define AUTHENTICATION_HEADER_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
  19 struct auth_hdrhdr {
  20         uint8_t h_next_header;
  21         uint8_t h_payload_len;
  22         uint16_t h_reserved;
  23         uint32_t h_spi;
  24         uint32_t h_snf;
  25 } __attribute__((packed));
  26
  27 static inline void auth_hdr(uint8_t *packet, size_t len)
  28 {
  29         uint8_t hdr_payload_len;
  30         struct auth_hdrhdr *auth_hdr = (struct auth_hdrhdr *) packet;
  31
  32         hdr_payload_len = (auth_hdr->h_payload_len * 4) + 8;
  33         if (len < hdr_payload_len || len < sizeof(struct auth_hdrhdr))
  34                 return;
  35
  36         tprintf(" [ Authentication Header ");
  37         tprintf("NextHdr (%u), ", auth_hdr->h_next_header);
  38         tprintf("HdrLen (%u), ", hdr_payload_len);
  39         tprintf("Reserved (0x%x), ", ntohs(auth_hdr->h_reserved));
  40         tprintf("SPI (0x%x), ", ntohl(auth_hdr->h_spi));
  41         tprintf("SNF (0x%x), ", ntohl(auth_hdr->h_snf));
  42         tprintf("ICV 0x");
  43         for (uint8_t i = sizeof(struct auth_hdrhdr); i < hdr_payload_len; i++)
  44                 tprintf("%02x",(uint8_t) packet[i]);
  45         tprintf(" ]\n");
  46 }
  47
  48 static inline void auth_hdr_less(uint8_t *packet, size_t len)
  49 {
  50         uint8_t hdr_payload_len;
  51         struct auth_hdrhdr *auth_hdr = (struct auth_hdrhdr *) packet;
  52
  53         hdr_payload_len = (auth_hdr->h_payload_len * 4) + 8;
  54         if (len < hdr_payload_len || len < sizeof(struct auth_hdrhdr))
  55                 return;
  56
  57         tprintf(" AH");
  58 }
  59
  60 static inline void auth_hdr_next(uint8_t *packet, size_t len,
  61                                  struct hash_table **table,
  62                                  unsigned int *key, size_t *off)
  63 {
  64         uint8_t hdr_payload_len;
  65         struct auth_hdrhdr *auth_hdr = (struct auth_hdrhdr *) packet;
  66
  67         hdr_payload_len = (auth_hdr->h_payload_len * 4) + 8;
  68         if (len < hdr_payload_len || len < sizeof(struct auth_hdrhdr))
  69                 return;
  70
  71         (*off) = hdr_payload_len;
  72         (*key) = auth_hdr->h_next_header;
  73         (*table) = &eth_lay3;
  74 }
  75
  76 struct protocol ip_auth_hdr_ops = {
  77         .key = 0x33,
  78         .print_full = auth_hdr,
  79         .print_less = auth_hdr_less,
  80         .print_pay_ascii = empty,
  81         .print_pay_hex = empty,
  82         .print_pay_none = auth_hdr,
  83         .print_all_hex = hex,
  84         .proto_next = auth_hdr_next,
  85 };
  86
  87 #endif /* AUTHENTICATION_HEADER_H */