FreeRTOS/Common/ethernet/lwIP/core/inet.c

   1 /*
   2  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification,
   6  * are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  19  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  25  * OF SUCH DAMAGE.
  26  *
  27  * This file is part of the lwIP TCP/IP stack.
  28  *
  29  * Author: Adam Dunkels <adam@sics.se>
  30  *
  31  */
  32
  33
  34 /* inet.c
  35  *
  36  * Functions common to all TCP/IP modules, such as the Internet checksum and the
  37  * byte order functions.
  38  *
  39  */
  40
  41
  42 #include "lwip/opt.h"
  43
  44 #include "lwip/arch.h"
  45
  46 #include "lwip/def.h"
  47 #include "lwip/inet.h"
  48
  49 #include "lwip/sys.h"
  50
  51 /* These are some reference implementations of the checksum algorithm, with the
  52  * aim of being simple, correct and fully portable. Checksumming is the
  53  * first thing you would want to optimize for your platform. If you create
  54  * your own version, link it in and in your sys_arch.h put:
  55  *
  56  * #define LWIP_CHKSUM <your_checksum_routine>
  57 */
  58 #ifndef LWIP_CHKSUM
  59 #define LWIP_CHKSUM lwip_standard_chksum
  60
  61 #if 1 /* Version A */
  62 /**
  63  * lwip checksum
  64  *
  65  * @param dataptr points to start of data to be summed at any boundary
  66  * @param len length of data to be summed
  67  * @return host order (!) lwip checksum (non-inverted Internet sum)
  68  *
  69  * @note accumulator size limits summable length to 64k
  70  * @note host endianess is irrelevant (p3 RFC1071)
  71  */
  72 static u16_t
  73 lwip_standard_chksum(void *dataptr, u16_t len)
  74 {
  75   u32_t acc;
  76   u16_t src;
  77   u8_t *octetptr;
  78
  79   acc = 0;
  80   /* dataptr may be at odd or even addresses */
  81   octetptr = (u8_t*)dataptr;
  82   while (len > 1)
  83   {
  84     /* declare first octet as most significant
  85        thus assume network order, ignoring host order */
  86     src = (*octetptr) << 8;
  87     octetptr++;
  88     /* declare second octet as least significant */
  89     src |= (*octetptr);
  90     octetptr++;
  91     acc += src;
  92     len -= 2;
  93   }
  94   if (len > 0)
  95   {
  96     /* accumulate remaining octet */
  97     src = (*octetptr) << 8;
  98     acc += src;
  99   }
 100   /* add deferred carry bits */
 101   acc = (acc >> 16) + (acc & 0x0000ffffUL);
 102   if ((acc & 0xffff0000) != 0) {
 103     acc = (acc >> 16) + (acc & 0x0000ffffUL);
 104   }
 105   /* This maybe a little confusing: reorder sum using htons()
 106      instead of ntohs() since it has a little less call overhead.
 107      The caller must invert bits for Internet sum ! */
 108   return htons((u16_t)acc);
 109 }
 110 #endif
 111
 112 #if 0 /* Version B */
 113 /*
 114  * Curt McDowell
 115  * Broadcom Corp.
 116  * csm@broadcom.com
 117  *
 118  * IP checksum two bytes at a time with support for
 119  * unaligned buffer.
 120  * Works for len up to and including 0x20000.
 121  * by Curt McDowell, Broadcom Corp. 12/08/2005
 122  */
 123
 124 static u16_t
 125 lwip_standard_chksum(void *dataptr, int len)
 126 {
 127   u8_t *pb = dataptr;
 128   u16_t *ps, t = 0;
 129   u32_t sum = 0;
 130   int odd = ((u32_t)pb & 1);
 131
 132   /* Get aligned to u16_t */
 133   if (odd && len > 0) {
 134     ((u8_t *)&t)[1] = *pb++;
 135     len--;
 136   }
 137
 138   /* Add the bulk of the data */
 139   ps = (u16_t *)pb;
 140   while (len > 1) {
 141     sum += *ps++;
 142     len -= 2;
 143   }
 144
 145   /* Consume left-over byte, if any */
 146   if (len > 0)
 147     ((u8_t *)&t)[0] = *(u8_t *)ps;;
 148
 149   /* Add end bytes */
 150   sum += t;
 151
 152   /*  Fold 32-bit sum to 16 bits */
 153   while (sum >> 16)
 154     sum = (sum & 0xffff) + (sum >> 16);
 155
 156   /* Swap if alignment was odd */
 157   if (odd)
 158     sum = ((sum & 0xff) << 8) | ((sum & 0xff00) >> 8);
 159
 160   return sum;
 161 }
 162 #endif
 163
 164 #if 0 /* Version C */
 165 /**
 166  * An optimized checksum routine. Basically, it uses loop-unrolling on
 167  * the checksum loop, treating the head and tail bytes specially, whereas
 168  * the inner loop acts on 8 bytes at a time.
 169  *
 170  * @arg start of buffer to be checksummed. May be an odd byte address.
 171  * @len number of bytes in the buffer to be checksummed.
 172  *
 173  * by Curt McDowell, Broadcom Corp. December 8th, 2005
 174  */
 175
 176 static u16_t
 177 lwip_standard_chksum(void *dataptr, int len)
 178 {
 179   u8_t *pb = dataptr;
 180   u16_t *ps, t = 0;
 181   u32_t *pl;
 182   u32_t sum = 0, tmp;
 183   /* starts at odd byte address? */
 184   int odd = ((u32_t)pb & 1);
 185
 186   if (odd && len > 0) {
 187     ((u8_t *)&t)[1] = *pb++;
 188     len--;
 189   }
 190
 191   ps = (u16_t *)pb;
 192
 193   if (((u32_t)ps & 3) && len > 1) {
 194     sum += *ps++;
 195     len -= 2;
 196   }
 197
 198   pl = (u32_t *)ps;
 199
 200   while (len > 7)  {
 201     tmp = sum + *pl++;          /* ping */
 202     if (tmp < sum)
 203       tmp++;                    /* add back carry */
 204
 205     sum = tmp + *pl++;          /* pong */
 206     if (sum < tmp)
 207       sum++;                    /* add back carry */
 208
 209     len -= 8;
 210   }
 211
 212   /* make room in upper bits */
 213   sum = (sum >> 16) + (sum & 0xffff);
 214
 215   ps = (u16_t *)pl;
 216
 217   /* 16-bit aligned word remaining? */
 218   while (len > 1) {
 219     sum += *ps++;
 220     len -= 2;
 221   }
 222
 223   /* dangling tail byte remaining? */
 224   if (len > 0)                  /* include odd byte */
 225     ((u8_t *)&t)[0] = *(u8_t *)ps;
 226
 227   sum += t;                     /* add end bytes */
 228
 229   while (sum >> 16)             /* combine halves */
 230     sum = (sum >> 16) + (sum & 0xffff);
 231
 232   if (odd)
 233     sum = ((sum & 0xff) << 8) | ((sum & 0xff00) >> 8);
 234
 235   return sum;
 236 }
 237 #endif
 238
 239 #endif /* LWIP_CHKSUM */
 240
 241 /* inet_chksum_pseudo:
 242  *
 243  * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
 244  */
 245
 246 u16_t
 247 inet_chksum_pseudo(struct pbuf *p,
 248        struct ip_addr *src, struct ip_addr *dest,
 249        u8_t proto, u16_t proto_len)
 250 {
 251   u32_t acc;
 252   struct pbuf *q;
 253   u8_t swapped;
 254
 255   acc = 0;
 256   swapped = 0;
 257   /* iterate through all pbuf in chain */
 258   for(q = p; q != NULL; q = q->next) {
 259     LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
 260       (void *)q, (void *)q->next));
 261     acc += LWIP_CHKSUM(q->payload, q->len);
 262     /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
 263     while (acc >> 16) {
 264       acc = (acc & 0xffffUL) + (acc >> 16);
 265     }
 266     if (q->len % 2 != 0) {
 267       swapped = 1 - swapped;
 268       acc = ((acc & 0xff) << 8) | ((acc & 0xff00UL) >> 8);
 269     }
 270     /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
 271   }
 272
 273   if (swapped) {
 274     acc = ((acc & 0xff) << 8) | ((acc & 0xff00UL) >> 8);
 275   }
 276   acc += (src->addr & 0xffffUL);
 277   acc += ((src->addr >> 16) & 0xffffUL);
 278   acc += (dest->addr & 0xffffUL);
 279   acc += ((dest->addr >> 16) & 0xffffUL);
 280   acc += (u32_t)htons((u16_t)proto);
 281   acc += (u32_t)htons(proto_len);
 282
 283   while (acc >> 16) {
 284     acc = (acc & 0xffffUL) + (acc >> 16);
 285   }
 286   LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
 287   return (u16_t)~(acc & 0xffffUL);
 288 }
 289
 290 /* inet_chksum:
 291  *
 292  * Calculates the Internet checksum over a portion of memory. Used primarily for IP
 293  * and ICMP.
 294  */
 295
 296 u16_t
 297 inet_chksum(void *dataptr, u16_t len)
 298 {
 299   u32_t acc;
 300
 301   acc = LWIP_CHKSUM(dataptr, len);
 302   while (acc >> 16) {
 303     acc = (acc & 0xffff) + (acc >> 16);
 304   }
 305   return (u16_t)~(acc & 0xffff);
 306 }
 307
 308 u16_t
 309 inet_chksum_pbuf(struct pbuf *p)
 310 {
 311   u32_t acc;
 312   struct pbuf *q;
 313   u8_t swapped;
 314
 315   acc = 0;
 316   swapped = 0;
 317   for(q = p; q != NULL; q = q->next) {
 318     acc += LWIP_CHKSUM(q->payload, q->len);
 319     while (acc >> 16) {
 320       acc = (acc & 0xffffUL) + (acc >> 16);
 321     }
 322     if (q->len % 2 != 0) {
 323       swapped = 1 - swapped;
 324       acc = (acc & 0x00ffUL << 8) | (acc & 0xff00UL >> 8);
 325     }
 326   }
 327
 328   if (swapped) {
 329     acc = ((acc & 0x00ffUL) << 8) | ((acc & 0xff00UL) >> 8);
 330   }
 331   return (u16_t)~(acc & 0xffffUL);
 332 }
 333
 334 /* Here for now until needed in other places in lwIP */
 335 #ifndef isprint
 336 #define in_range(c, lo, up)  ((u8_t)c >= lo && (u8_t)c <= up)
 337 #define isprint(c)           in_range(c, 0x20, 0x7f)
 338 #define isdigit(c)           in_range(c, '0', '9')
 339 #define isxdigit(c)          (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
 340 #define islower(c)           in_range(c, 'a', 'z')
 341 #define isspace(c)           (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
 342 #endif
 343
 344 /*
 345  * Ascii internet address interpretation routine.
 346  * The value returned is in network order.
 347  */
 348
 349 u32_t
 350 inet_addr(const char *cp)
 351 {
 352   struct in_addr val;
 353
 354   if (inet_aton(cp, &val)) {
 355     return (val.s_addr);
 356   }
 357   return (INADDR_NONE);
 358 }
 359
 360 /*
 361  * Check whether "cp" is a valid ascii representation
 362  * of an Internet address and convert to a binary address.
 363  * Returns 1 if the address is valid, 0 if not.
 364  * This replaces inet_addr, the return value from which
 365  * cannot distinguish between failure and a local broadcast address.
 366  */
 367 int
 368 inet_aton(const char *cp, struct in_addr *addr)
 369 {
 370   u32_t val;
 371   int base, n, c;
 372   u32_t parts[4];
 373   u32_t *pp = parts;
 374
 375   c = *cp;
 376   for (;;) {
 377     /*
 378      * Collect number up to ``.''.
 379      * Values are specified as for C:
 380      * 0x=hex, 0=octal, 1-9=decimal.
 381      */
 382     if (!isdigit(c))
 383       return (0);
 384     val = 0;
 385     base = 10;
 386     if (c == '0') {
 387       c = *++cp;
 388       if (c == 'x' || c == 'X') {
 389         base = 16;
 390         c = *++cp;
 391       } else
 392         base = 8;
 393     }
 394     for (;;) {
 395       if (isdigit(c)) {
 396         val = (val * base) + (int)(c - '0');
 397         c = *++cp;
 398       } else if (base == 16 && isxdigit(c)) {
 399         val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A'));
 400         c = *++cp;
 401       } else
 402         break;
 403     }
 404     if (c == '.') {
 405       /*
 406        * Internet format:
 407        *  a.b.c.d
 408        *  a.b.c   (with c treated as 16 bits)
 409        *  a.b (with b treated as 24 bits)
 410        */
 411       if (pp >= parts + 3)
 412         return (0);
 413       *pp++ = val;
 414       c = *++cp;
 415     } else
 416       break;
 417   }
 418   /*
 419    * Check for trailing characters.
 420    */
 421   if (c != '\0' && (!isprint(c) || !isspace(c)))
 422     return (0);
 423   /*
 424    * Concoct the address according to
 425    * the number of parts specified.
 426    */
 427   n = pp - parts + 1;
 428   switch (n) {
 429
 430   case 0:
 431     return (0);       /* initial nondigit */
 432
 433   case 1:             /* a -- 32 bits */
 434     break;
 435
 436   case 2:             /* a.b -- 8.24 bits */
 437     if (val > 0xffffff)
 438       return (0);
 439     val |= parts[0] << 24;
 440     break;
 441
 442   case 3:             /* a.b.c -- 8.8.16 bits */
 443     if (val > 0xffff)
 444       return (0);
 445     val |= (parts[0] << 24) | (parts[1] << 16);
 446     break;
 447
 448   case 4:             /* a.b.c.d -- 8.8.8.8 bits */
 449     if (val > 0xff)
 450       return (0);
 451     val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
 452     break;
 453   }
 454   if (addr)
 455     addr->s_addr = htonl(val);
 456   return (1);
 457 }
 458
 459 /* Convert numeric IP address into decimal dotted ASCII representation.
 460  * returns ptr to static buffer; not reentrant!
 461  */
 462 char *
 463 inet_ntoa(struct in_addr addr)
 464 {
 465   static char str[16];
 466   u32_t s_addr = addr.s_addr;
 467   char inv[3];
 468   char *rp;
 469   u8_t *ap;
 470   u8_t rem;
 471   u8_t n;
 472   u8_t i;
 473
 474   rp = str;
 475   ap = (u8_t *)&s_addr;
 476   for(n = 0; n < 4; n++) {
 477     i = 0;
 478     do {
 479       rem = *ap % (u8_t)10;
 480       *ap /= (u8_t)10;
 481       inv[i++] = '0' + rem;
 482     } while(*ap);
 483     while(i--)
 484       *rp++ = inv[i];
 485     *rp++ = '.';
 486     ap++;
 487   }
 488   *--rp = 0;
 489   return str;
 490 }
 491
 492 /*
 493  * These are reference implementations of the byte swapping functions.
 494  * Again with the aim of being simple, correct and fully portable.
 495  * Byte swapping is the second thing you would want to optimize. You will
 496  * need to port it to your architecture and in your cc.h:
 497  *
 498  * #define LWIP_PLATFORM_BYTESWAP 1
 499  * #define LWIP_PLATFORM_HTONS(x) <your_htons>
 500  * #define LWIP_PLATFORM_HTONL(x) <your_htonl>
 501  *
 502  * Note ntohs() and ntohl() are merely references to the htonx counterparts.
 503  */
 504
 505 #ifndef BYTE_ORDER
 506 #error BYTE_ORDER is not defined
 507 #endif
 508 #if (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN)
 509
 510 u16_t
 511 htons(u16_t n)
 512 {
 513   return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);
 514 }
 515
 516 u16_t
 517 ntohs(u16_t n)
 518 {
 519   return htons(n);
 520 }
 521
 522 u32_t
 523 htonl(u32_t n)
 524 {
 525   return ((n & 0xff) << 24) |
 526     ((n & 0xff00) << 8) |
 527     ((n & 0xff0000) >> 8) |
 528     ((n & 0xff000000) >> 24);
 529 }
 530
 531 u32_t
 532 ntohl(u32_t n)
 533 {
 534   return htonl(n);
 535 }
 536
 537 #endif /* (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN) */