src/hextools.c

   1 /*
   2  * Mausezahn - A fast versatile traffic generator
   3  * Copyright (C) 2008 Herbert Haas
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License version 2 as published by the
   7  * Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
  12  * details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, see http://www.gnu.org/licenses/gpl-2.0.html
  16  *
  17 */
  18
  19
  20
  21
  22
  23 ///////////////////////////////////////////////////////////////////////////////////////////
  24 //
  25 //  Contains various tools for hex-based conversions and manipulation of bytestrings
  26 //
  27 //  str2hex_mac     ..... converts "00:01:02:0a:ff:ff" into       u_int8_t dst[6]
  28 //  str2hex         ..... converts "1a 00:00-2f"       into       u_int8_t dst[n] (any length)
  29 //  num2hex         ..... converts "192.16.1.1"        into       u_int8_t dst[4]
  30 //  bs2str          ..... converts {0,1,10}            into       "00-01-0A"
  31 //  getbytes        ..... a stupid implementation of memcpy - prefer memcpy instead !!!
  32 //  str2ip32        ..... converts "192.168.0.1"       into       3232235521 (u_int32_t)
  33 //  str2ip32_rev    .....          same but assumes network byte order
  34 //  type2str        ..... converts a u_int16_t into a string, e. g. 0x800 into "08:00"
  35 //
  36 ////////////////////////////////////////////////////////////////////////////////////////////
  37
  38
  39 #include "mz.h"
  40
  41
  42
  43 // converts MAC address specified in str into u_int8_t array
  44 // Usage: str2hex_mac ( "00:01:02:aa:ff:ee", src_addr )
  45 // Returns 1 if specified MAC address string is invalid, 0 upon success.
  46 int str2hex_mac(char* str, u_int8_t *addr)
  47 {
  48    char *hs;
  49    int i;
  50    unsigned int test;
  51    char tmp[32];
  52
  53    strcpy(tmp,str); // necessary because strtok cannot operate on fixed strings
  54
  55    hs=(char*)strtok(tmp,"-:., ");
  56
  57    for (i=0; i<6; i++)
  58      {
  59         test = (unsigned int) strtol (hs, NULL, 16);
  60         if (test>0xff) return 1;
  61         addr[i]=(u_int8_t) strtol (hs, NULL, 16);
  62         hs = strtok(NULL,"-:., ");
  63         if ( (hs == NULL ) && (i!=5) )
  64              {
  65                 // Not a valid MAC address
  66                 return 1;
  67              }
  68      }
  69
  70    if (hs!=NULL) return 1; // more than 6 bytes
  71
  72    return 0;
  73 }
  74
  75
  76
  77
  78 // Converts ascii hex values (string) into integer array
  79 // For example "1a 00:00-2f" will be converted to {26, 0, 0, 47}
  80 //
  81 // NOTE: n ist the max number of bytes to be converted
  82 //
  83 // RETURN VALUE: number of bytes converted
  84 //               or -1 upon failure
  85 //
  86 int str2hex(char* str, u_int8_t *hp, int n)
  87 {
  88         char *hs;
  89         int curval,i;
  90
  91
  92         if (strlen(str)==0) return 0;
  93
  94         char tmp[8192]=""; //for very long payloads
  95
  96         strncpy(tmp,str,8191); // necessary because strtok cannot operate on fixed strings
  97
  98         hs=(char*)strtok(tmp,"-:., ");
  99
 100         i=0;
 101         do
 102         {       n--;
 103                 curval=strtol(hs,NULL,16);
 104                 if (curval>0xff) return -1;
 105                 hp[i]=(u_int8_t) curval;
 106                 i++;
 107         }
 108         while ((n) && ((hs=(char*)strtok(NULL,"-:., "))!= NULL));
 109
 110         return i; // return the length of the array
 111 }
 112
 113
 114
 115 // Converts ascii numbers (terminated string) into integer array
 116 // Every byte can be specified as integers {0..255}
 117 // For example "192.16.1.1" will be converted to {C0, 10, 01, 01}
 118 //
 119 // NOTE: Returns the number of converted bytes!
 120 int num2hex(char* str, u_int8_t *hp)
 121 {
 122    char *hs;
 123    int i;
 124    unsigned int curval;
 125
 126    if (strlen(str)==0) return 0;
 127
 128    char tmp[8192]=""; //for very long payloads
 129
 130    strncpy(tmp,str,8192); // necessary because strtok cannot operate on fixed strings
 131
 132    hs = (char*) strtok (tmp,"-:., ");
 133
 134    i=0;
 135    do
 136      {
 137         curval =  (unsigned int) str2int(hs);
 138         if (curval<256)
 139           {
 140              hp[i] = (u_int8_t) curval;
 141              i++;
 142           }
 143      }
 144    while ((hs=(char*)strtok(NULL,"-:., "))!= NULL);
 145    //hp[i]='\0'; // termination not necessary
 146
 147    return i;
 148 }
 149
 150
 151
 152 // Convert array of integers into string of hex
 153 // E.g. {0,1,10} => "00-01-0A"
 154 // Useful for verification messages.
 155 int bs2str(u_int8_t *bs, char* str, int len)
 156 {
 157    int i;
 158    char t[4];
 159
 160    str[0]='\0';
 161
 162    for (i=0; i<len; i++)
 163      {
 164 //      if (bs[i]<16) strcat(str,"0"); // enforce two hex digits (e.g. "0a")
 165
 166         sprintf(t,"%02x:",bs[i]);
 167         strcat(str,t);
 168      }
 169    str[strlen(str)-1]='\0'; //remove the last ":"
 170    return 1;
 171 }
 172
 173
 174 // Extract contiguous sequence of bytes from an array
 175 // NOTE: first element has number 1 !!!
 176 // THIS IS DEPRECATED: PREFER memcpy INSTEAD !!!
 177 int getbytes(u_int8_t *source,
 178              u_int8_t *target,
 179              int from,
 180              int to)
 181
 182 {
 183    int i;
 184
 185    // Check wrong arguments
 186    if  (from<1)
 187      {
 188         return -1;
 189      }
 190
 191    // copy bytes
 192    for (i=0; i<(to-from+1); i++)
 193        {
 194           target[i]=source[from-1+i];
 195        }
 196
 197    return 1;
 198 }
 199
 200
 201 // Converts an  IP address given in 'dotted decimal' into an unsigned 32-bit integer
 202 // Example: "192.168.0.1" => 3232235521
 203 u_int32_t str2ip32 (char* str)
 204 {
 205         u_int32_t ip = 0;
 206         unsigned int a,b,c,d;
 207         int r;
 208
 209         // check whether str really contains an IP address
 210         if (strlen(str)<3) return 0;
 211         if (str==NULL) return 0;
 212
 213         if ((r=sscanf(str,"%i.%i.%i.%i",&a,&b,&c,&d))==0) return 0;
 214         if (r==EOF) return 0;
 215
 216         /* or an alternative method...
 217         // these are the four bytes of a dotted decimal notation IP address:
 218         a = (unsigned int) strtol(strtok(str,"."), (char **)NULL, 10);
 219         b = (unsigned int) strtol(strtok(NULL,"."), (char **)NULL, 10);
 220         c = (unsigned int) strtol(strtok(NULL,"."), (char **)NULL, 10);
 221         d = (unsigned int) strtol(strtok(NULL,"."), (char **)NULL, 10);
 222         */
 223
 224         if ((a>255)||(b>255)||(c>255)||(d>255)) return 0;
 225
 226         ip = d + 256*c + 256*256*b + 256*256*256*a;
 227
 228         //check with:
 229         //printf("str2ip32 got 4 bytes: %i %i %i %i\n",a,b,c,d);
 230         //printf("str2ip32 returned %u\n",ip);
 231
 232         return ip;
 233 }
 234
 235
 236 // Converts an  IP address given in 'dotted decimal' into an unsigned 32-bit integer
 237 // This version does the same as str2ip32() but in 'network byte order'
 238 u_int32_t str2ip32_rev (char* str)
 239 {
 240         u_int32_t ip = 0;
 241         unsigned int a,b,c,d;
 242         int r;
 243
 244         // check whether str really contains an IP address
 245         if (strlen(str)<3) return 0;
 246         if (str==NULL) return 0;
 247
 248         if ((r=sscanf(str,"%i.%i.%i.%i",&a,&b,&c,&d))==0) return 0;
 249         if (r==EOF) return 0;
 250
 251         /* or an alternative method...
 252         // these are the four bytes of a dotted decimal notation IP address:
 253         a = (unsigned int) strtol(strtok(str,"."), (char **)NULL, 10);
 254         b = (unsigned int) strtol(strtok(NULL,"."), (char **)NULL, 10);
 255         c = (unsigned int) strtol(strtok(NULL,"."), (char **)NULL, 10);
 256         d = (unsigned int) strtol(strtok(NULL,"."), (char **)NULL, 10);
 257         */
 258
 259         if ((a>255)||(b>255)||(c>255)||(d>255)) return 0;
 260
 261         ip = a + b*256 + c*256*256 + d*256*256*256;
 262
 263         //check with:
 264         //printf("str2ip32 got 4 bytes: %i %i %i %i\n",a,b,c,d);
 265         //printf("str2ip32 returned %u\n",ip);
 266
 267         return ip;
 268 }
 269
 270
 271 // Converts a 2-byte value (e. g. a EtherType field)
 272 // into a nice string using hex notation.
 273 // Useful for verification messages.
 274 // Example: type2str (tx.eth_type, msg) may result in msg="08:00"
 275 // Return value: how many hex digits have been found.
 276 int type2str(u_int16_t type, char *str)
 277 {
 278    char hex[8];
 279    int i=0;
 280
 281    (void) sprintf (hex, "%x",type);
 282    i=strlen(hex);
 283
 284    switch (i)
 285      {
 286       case 1:
 287         str[0]='0';
 288         str[1]='0';
 289         str[2]=':';
 290         str[3]='0';
 291         str[4]=hex[0];
 292         str[5]='\0';
 293         break;
 294       case 2:
 295         str[0]='0';
 296         str[1]='0';
 297         str[2]=':';
 298         str[3]=hex[0];
 299         str[4]=hex[1];
 300         str[5]='\0';
 301         break;
 302       case 3:
 303         str[0]='0';
 304         str[1]=hex[0];
 305         str[2]=':';
 306         str[3]=hex[1];
 307         str[4]=hex[2];
 308         str[5]='\0';
 309         break;
 310       case 4:
 311         str[0]=hex[0];
 312         str[1]=hex[1];
 313         str[2]=':';
 314         str[3]=hex[2];
 315         str[4]=hex[3];
 316         str[5]='\0';
 317         break;
 318
 319      }
 320    return i;
 321 }
 322