src/header.c

   1 /*======================================================================*
   2  * Copyright (C) 2008 Light Weight Event System                         *
   3  * All rights reserved.                                                 *
   4  *                                                                      *
   5  * This program is free software; you can redistribute it and/or modify *
   6  * it under the terms of the GNU General Public License as published by *
   7  * the Free Software Foundation; either version 2 of the License, or    *
   8  * (at your option) any later version.                                  *
   9  *                                                                      *
  10  * This program is distributed in the hope that it will be useful,      *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  13  * GNU General Public License for more details.                         *
  14  *                                                                      *
  15  * You should have received a copy of the GNU General Public License    *
  16  * along with this program; if not, write to the Free Software          *
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                   *
  18  * Boston, MA 02110-1301 USA.                                           *
  19  *======================================================================*/
  20 #include "config.h"
  21
  22 #include "header.h"
  23
  24 #include "log.h"
  25 #include "opt.h"
  26 #include "stats.h"
  27
  28 #include "lwes.h"
  29 #include "marshal.h"
  30
  31 #include <sys/socket.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34
  35 #define ntohll(x) ( ( (uint64_t)(ntohl( (uint32_t)((x << 32) >> 32) )) << 32) | ntohl( ((uint32_t)(x >> 32)) ) )
  36
  37 void header_add(void* buf, int count, unsigned long addr, unsigned short port)
  38 {
  39   unsigned char*     cp = (unsigned char*)buf;
  40   unsigned long long tm = time_in_milliseconds();
  41
  42   marshal_short(cp, count);    /* Size of message body. */
  43   marshal_ulong_long(cp, tm);  /* Now in msec. */
  44   marshal_long(cp, addr);      /* Sender IP address. */
  45   marshal_short(cp, port);     /* Sender port number. */
  46   marshal_short(cp, arg_site); /* Site ID number */
  47   /* TODO: should be perfectly alright, but un-QA'd  marshal_long(cp, 0); */
  48   /* reserved */
  49 }
  50
  51 int header_is_rotate (void* buf)
  52 {
  53   return toknam_eq((unsigned char *)buf + HEADER_LENGTH,
  54                    (unsigned char *)ROTATE_COMMAND);
  55   LOG_PROG("Command::Rotate message received.\n");
  56 }
  57
  58 void header_fingerprint(void* buf, struct packet_check* pc)
  59 {
  60   unsigned char* cp = (unsigned char*)buf;
  61   long long zero = 0LL;
  62   unsigned long long tm;
  63   short length;
  64
  65   /* Extract the timestamp. */
  66   unmarshal_short(cp, length);
  67   unmarshal_ulong_long(cp, tm);
  68
  69   /* Add phony timestamp of zero. */
  70   cp -= 8;
  71   marshal_long_long(cp, zero);
  72
  73   pc->received = tm;
  74   /* pc->md5 = md5(); */
  75 }
  76
  77 /////////////////////////////////////////////////////////////////////////////
  78 // It's a small thing, but toknam_eq() is quicker than memcmp().
  79 //   * memcmp does a tremendous amount of setup before comparing the first
  80 //     character (it's designed to compare large strings efficently)
  81 //   * we don't care if greater-than or less-than, just equal or not
  82 //   * syntactically simpler (taking advantage of token's length byte)
  83 int toknam_eq(const unsigned char* toknam, const unsigned char* nam)
  84 {
  85   unsigned char len = *nam+1 ;
  86   while ( *toknam++ == *nam++ )
  87     if ( --len == 0 )
  88       return 1 ;
  89   return 0 ;
  90 }
  91
  92 /////////////////////////////////////////////////////////////////////////////
  93
  94 void header_print (const char* buf)
  95 {
  96   LOG_INF("header payload length: %u\n",   header_payload_length(buf));
  97   LOG_INF("receipt time:          %llu\n", header_receipt_time(buf));
  98   LOG_INF("now:                   %llu\n", time(NULL)*1000L);
  99   LOG_INF("sender IP text:        %s\n",   header_sender_ip_formatted(buf));
 100   LOG_INF("sender port:           %u\n",   header_sender_port(buf));
 101   LOG_INF("site id:               %u\n",   header_site_id(buf));
 102 }
 103
 104 static uint16_t header_uint16(const char* bytes) {
 105   return ntohs(*((uint16_t*) bytes));
 106 }
 107
 108 static uint32_t header_uint32(const char* bytes) {
 109   return ntohl(*((uint32_t*) bytes));
 110 }
 111
 112 static uint64_t header_uint64(const char* bytes) {
 113   return (((uint64_t)header_uint32(bytes))<<32) | header_uint32(bytes+4);
 114 }
 115
 116 uint16_t header_payload_length(const char* header)
 117 {
 118   return header_uint16(header);
 119 }
 120
 121 uint64_t header_receipt_time(const char* header) {
 122   return header_uint64(header+RECEIPT_TIME_OFFSET);
 123 }
 124
 125 const char* header_sender_ip_formatted(const char* header) {
 126   struct in_addr addr = { header_uint32(header+SENDER_IP_OFFSET) };
 127   return inet_ntoa(addr);
 128 }
 129
 130 uint16_t header_sender_port(const char* header) {
 131   return header_uint16(header+SENDER_PORT_OFFSET);
 132 }
 133
 134 uint16_t header_site_id(const char* header) {
 135   return header_uint16(header+SITE_ID_OFFSET);
 136 }
 137
 138 /* end-of-file */